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Biomedical subjects

B Devaux

Publications and source records attributed to B Devaux.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Intracavernous extension of hypophyseal macroadenomas: infiltration or invagination?].

Frequency of intracavernous invasion by a pituitary adenoma varies from 9% to 40% depending on the publications. Without putting off the possibility of true intracavernous invasion, it seems less frequent than evocated on CT-Scan and/or MRI data. We studied 153 files of pituitary adenomas operated upon recently: 72 prolactinomas (47.3%), 30 GH-secreting adenomas (19.7%), 7 corticotrop adenomas (4.6%), 44 non secreting adenomas (28.3%). 108 patients (70.4%) harboured a macroadenoma (diameter > 10 mm). A suprasellar expansion was seen 90 times on CT-Scan and/or MRI views. 19 times (17.7% of macroadenomas, 12.5% of the whole series) MRI evocated an infiltration of one or both cavernous sinuses (CS). Such data were found 3 times before 1991, 16 times since 1991, i.e. since MRI is systematically performed preoperatively. Except in two patients who respectively presented with a large intraorbital or temporal expansion, we have not been able to confirm the reality of the intracavernous invasion. We think that most of CT-Scan or MRI data of so-called intracavernous invasion correspond in fact to a compression or to a fingerglove invagination of the medial wall of the CS. In fact, anatomical studies by Harris & Rhoton (1976) and by Taptas (1990) demonstrated that such an invagination of the medial wall exists in almost one third of normal pituitary glands. These data must bring up to much carefulness when considering a possible pathological CS invasion by a macroadenoma. Therefore, it should be thoroughly assessed with anatomoradiological and radio-surgical correlations.

Adenoma↗
PubMed1998

[Controversies in the management of operated pituitary macroadenomas].

BACKGROUND AND PURPOSE: Complete resection of a pituitary adenoma is feasible in almost 50 to 70% of cases. Dealing with the remnant is still controversial. Three positions can be discussed: second stage operation, radiation therapy, clinical and radiological follow-up. METHODS: Among 108 pituitary macroadenomas operated on during the last 10 years, 54 patients (50%) with partially removed tumors were studied. Three cases best illustrating the evolution of these remnants are reported. RESULTS: Late MRI performed 4 to 6 months postoperatively is more valuable than early MRI in the evaluation of these remnants, which can remain stable for a long period of time without any adjuvant treatment. CONCLUSION: MRI should be performed 4 to 6 months postoperatively. Rather than performing radiation therapy systematically for asymptomatic patients, these patients should be followed up at regular intervals and treated only in case of regrowth of the tumor.

Adenoma↗
PubMed1997

A GPI-linked protein that interacts with Ret to form a candidate neurturin receptor.

Glial-cell-line-derived neurotrophic factor (GDNF) and neurturin (NTN) are two structurally related, potent survival factors for sympathetic, sensory and central nervous system neurons. GDNF mediates its actions through a multicomponent receptor system composed of a ligand-binding glycosyl-phosphatidylinositol (GPI)-linked protein (designated GDNFR-alpha) and the transmembrane protein tyrosine kinase Ret. In contrast, the mechanism by which the NTN signal is transmitted is not well understood. Here we describe the identification and tissue distribution of a GPI-linked protein (designated NTNR-alpha) that is structurally related to GDNFR-alpha. We further demonstrate that NTNR-alpha binds NTN (K[d] approximately 10 pM) but not GDNF with high affinity; that GDNFR-alpha binds to GDNF but not NTN with high affinity; and that cellular responses to NTN require the presence of NTNR-alpha. Finally, we show that NTN, in the presence of NTNR-alpha, induces tyrosine-phosphorylation of Ret, and that NTN, NTNR-alpha and Ret form a physical complex on the cell surface. These findings identify Ret and NTNR-alpha as signalling and ligand-binding components, respectively, of a receptor for NTN and define a novel family of receptors for neurotrophic and differentiation factors composed of a shared transmembrane protein tyrosine kinase and a ligand-specific GPI-linked protein.

Amino Acid Sequence↗
PubMed1997

Early versus delayed angiotensin-converting enzyme inhibition in experimental chronic heart failure. Effects on survival, hemodynamics, and cardiovascular remodeling.

BACKGROUND: The efficacy of ACE inhibitors in congestive heart failure (CHF) might be affected by the pathophysiological status present at the onset of treatment. We compared in a rat model the effects of ACE inhibition (lisinopril, 10 mg.kg-1.d-1) initiated early (1 week) or late (3 months) after myocardial infarction (i.e., at time points corresponding to moderate or severe CHF without or with established cardiac remodeling). METHODS AND RESULTS: Survival was improved by early treatment at 3 months (from 76% to 95%) and by both early and delayed treatment at 9 months (placebo, 28%; early, 90%; delayed, 61%). Delayed treatment was initiated in a more severe pathophysiological context of CHF than early treatment, illustrated in untreated rats by higher left ventricular (LV) end-diastolic and central venous pressures and by increased LV weight and LV cavity circumference. After 9 months, early and delayed treatments reduced systolic, LV end-diastolic, and central venous pressures. Both treatments also similarly decreased LV weight, LV cavity circumference, and LV collagen density. CONCLUSIONS: In this rat model of CHF, early and delayed ACE inhibitor treatments both increase survival and exert similar beneficial effects on cardiac hemodynamics and remodeling. Although early treatment prevents the development of ventricular dysfunction and remodeling, delayed treatment is capable of reversing cardiac hypertrophy and remodeling, as well as ventricular dysfunction. Thus, ACE inhibitors exert marked beneficial effects even when treatment is initiated late into the evolution of heart failure (ie, at a time of established ventricular dysfunction and remodeling).

Analysis of Variance↗
PubMed1997

Radiologic anatomy of segmental agenesis of the internal carotid artery.

We report six cases of segmental agenesis of the internal carotid a. discovered in adult patients: one case of cervical segmental agenesis (no. 1), one case of cervical and petrosal segmental agenesis (no. 2), two cases of vertical cavernous segmental agenesis (nos. 3 and 4) and two cases of distal segmental agenesis, one unilateral (no. 5) and the other bilateral (no. 6). The collateral pathways observed were: the ascending pharyngeal a. which constitutes an "intratympanic course" of the internal carotid a. (no. 1), an intercarotid anastomosis (no. 2), an arterial network at the base of the skull, the so-called "rete mirabile" (nos. 3 and 4) and the posterior communicating a. (nos. 5 and 6). Recognition of these rare dysgenesis relies upon the following radio-anatomic characteristics: reduced caliber of the a., inconsistent sparing of the carotid body, reduced diameter or even absence of the carotid canal and above all, the presence of collateral pathways. The collateral pathways allow an understanding of the segmental nature of carotid a. development and a distinction between congenital and acquired stenoses.

Adult↗
PubMed1997

The role of Fas/APO 1 and apoptosis in the development of human atherosclerotic lesions.

The possibility that Fas/APO 1 is involved in the apoptosis of advanced human coronary atherosclerosis was examined in the present study. Coronary arteries with atherosclerosis were obtained from human hearts with chronic ischemic heart disease at cardiac transplantation. Normal vessels were used as controls. Fas/APO 1 was detected by immunohistochemistry with a monoclonal antibody. Apoptotic cells were stained in situ by terminal deoxynucleotidyl transferase mediated-dUTP nick end labeling (TUNEL) and DNA fragmentation into oligonucleosomes was checked by gel electrophoresis. Bcl-2, an antiapoptotic oncoprotein, was detected by immunohistochemistry and Western blot. Apoptotic cells were present in the neointima in all stages of atherosclerosis, and in intraplaque small vessels. In initial lesions, only a few cells were undergoing apoptosis. By contrast, in advanced lesions, many cells were found to undergo apoptosis. Apoptosis was further confirmed by genomic DNA analysis using gel electrophoresis. Apoptotic cells were either smooth muscle cells or macrophages, but also endothelial and blood borne cells. Fas/APO 1 was present in foam cells. Most of the Fas/APO 1 positive cells were stained for the macrophage marker CD68 and for alpha-smooth muscle actin in serial sections. Several anti-Fas/APO 1 positive foam cells were revealed to undergo apoptosis by double staining. Bcl-2 was detected in Fas/APO 1 expressing plaques. A number of CD3-positive T-lymphocytes were found around foam cells expressing Fas/APO 1. This data suggests that Fas/APO 1 regulated apoptosis is involved in the development of advanced human atherosclerotic lesions and that it probably determines the amount of tissue mass in the diseased vessels.

Antibodies, Monoclonal↗
PubMed1997

Induction of EAE in mice with recombinant human MOG, and treatment of EAE with a MOG peptide.

Myelin oligodendrocyte glycoprotein (MOG) is a transmembrane glycoprotein expressed on the surface of central nervous system (CNS) myelin membranes, which has been shown to induce experimental autoimmune encephalomyelitis (EAE) in rodents. Here we describe the induction of EAE in SJL and (PLJ X SJL)F1 mice with truncated human recombinant MOG (thr-MOG, amino acids 1-120) which has been expressed in insect cells in soluble form. We show that in SJL mice, immunization with thr-MOG produces an immune response to the 1-30 and the 81-110 regions of the MOG molecule. We also demonstrate effective treatment of thr-MOG-induced EAE in SJL mice with intravenous injections of a single peptide, MOG 91-110. These results support the possibility of treating MS using an antigen dependent approach.

Amino Acid Sequence↗
PubMed1997

Upregulation of cell adhesion molecules and the presence of low grade inflammation in human chronic heart failure.

BACKGROUND: In the present study, the hypothesis was tested that cell adhesion molecules are expressed in failing human hearts and that a chronic inflammatory process contributes to chronic degeneration known to occur in cardiac incompetence. The cell adhesion molecules: ICAM-1, VCAM-1, PECAM-1, and E-selectin were studied, in addition to cellular markers of inflammation. METHODS AND RESULTS: Tissue was obtained at transplantation from patients with either myocarditis, chronic ischaemic heart disease, or dilated cardiomyopathy. Controls were taken from patients with normal ventricles. Cell adhesion molecules were qualitatively evaluated and counted using specific antibodies and confocal microscopy. Additionally, semiquantitative evaluation of the presence of the CD3 antigen (T-lymphocytes), CD68 (macrophages), CD11a/CD18 (ICAM-1 receptor) and human tumour necrosis factor-a were used as indicators of chronic inflammation. PECAM-1 stained all endothelial cells but ICAM-1 was only present in 80% of all capillaries in control tissue. The ratio ICAM-1/PECAM-1 was significantly enhanced in all groups of diseased hearts. Myocytes in myocarditic hearts expressed ICAM-ICAM. CD3 positive lymphocytes, CD68 positive macrophages and CD11a/CD18 positive cells were more abundantly present than in control. Macrophages expressing tumour necrosis factor-a were found in failing myocardium but not in control tissue. CONCLUSION: Independent of the cause of heart failure, chronic low grade inflammation is present in failing human myocardium. This may significantly contribute to the structural deterioration that is the basis of reduced cardiac function in congestive heart failure.

Adult↗
PubMed1997

Response of large and small vessels to alpha and beta adrenoceptor stimulation in heart failure: effect of angiotensin converting enzyme inhibition.

The increased sympathetic drive in chronic heart failure (CHF) might provoke vascular adrenoceptor desensitization, which, together with endothelial dysfunction, could contribute to the altered vasomotor tone seen in CHF. We investigated 1) whether CHF alters the responses mediated by alpha and beta adrenoceptors in small and large peripheral arteries, and 2) the effect of angiotensin-converting enzyme (ACE) inhibition. Rats with CHF (coronary artery ligation) were treated with placebo or the ACE inhibitor lisinopril (10 mg/kg/d) starting 7 days after ligation. Responses to phenylephrine (alpha 1 agonist), salbutamol (beta 2 agonist) as well as acetylcholine (endothelium-dependent), were assessed after 3 months in isolated and pressurized segments of the abdominal aorta, the femoral and the mesenteric arteries. In animals with hemodynamic signs of CHF, neither the vasoconstrictor responses to phenylephrine nor the vasodilator response to salbutamol were affected. In contrast, the dilator response to acetylcholine of both small arteries, but not that of the aorta, was impaired. Furthermore, CHF did not modify vessel structure. While lisinopril did not modify the responses to adrenergic agonists, it normalized the response to acetylcholine. Furthermore, ACE inhibition reduced vascular media cross sectional area and collagen density. Thus, the unchanged arterial responsiveness to adrenoceptor agonists does not indicate any vascular adrenoceptor desensitization, while endothelial dependent vasodilation of small arteries is impaired in CHF. ACE inhibition does not modify the response to adrenergic stimuli, prevents endothelial dysfunction and induces both cardiac and vascular remodeling, which probably contribute to the effect ACE inhibitors have on exercise tolerance and survival.

Acetylcholine↗
PubMed1997

Chronic intractable epilepsy associated with a tumor located in the central region: functional mapping data and postoperative outcome.

Out of 57 patients operated for intractable epilepsy of the central region, 8 harbored an indolent glioma (7 dysembryoplastic neuroepithelial tumors, 1 ganglioglioma). Mapping of the sensorimotor area with depth electrodes implanted for stereoelectroencephalographic exploration demonstrated no or abnormal motor responses after low-frequency stimulation, and variable sensory responses to high-frequency stimulation, suggesting reorganization of the sensorimotor cortex representation around the tumor and absence of functional tissue within the neoplastic volume. After lesionectomy (3 cases) or corticectomy including the tumor (5 cases), 6 (75%) patients were seizure-free (class I of Engel) at the time to follow-up. No permanent motor or sensory deficit was observed in 6 cases. In 2, a mild facial (in 1) and arm (in 1) deficit persisted. It is concluded that the resection of intrinsic low-grade tumors associated with long-standing epilepsy and located in the central region can be associated with excellent seizure outcome and no or minimal postoperative deficit because of functional reorganization of the sensorimotor cortex.

Adolescent↗
PubMed1997

[Trans-facial approaches of cancers of the ethmoid].

Lateral rhinotomy, midface degloving approach and medial maxillectomy are described. Lateral rhinotomy allows for a wide surgical approach, complete tumor removal with safe margins and satisfying cosmetic result. Lateral rhinotomy with medial maxillectomy is recommended for surgical resection of ethmoid sinus carcinoma. This surgical approach allows for a simultaneous neurosurgical subfrontal approach.

Ethmoid Sinus↗
PubMed1997

[Malignant tumors of the ethmoid region. Neurosurgical techniques].

We describe the main neurosurgical approaches in use for removing cancers of the ethmoid region: a) the classical subfrontal procedure usually combined with a transfacial approach, b) the sub-fronto-orbito-nasal approach (SFON) now performed in a majority of procedures as long as the tumor does not present with a large intra-cranial and/or maxillary extension. The advantages and drawbacks of both techniques are discussed. The progressive simplification of techniques for anterior cranial base reconstruction is explained and warranted.

Ethmoid Bone↗
PubMed1997

[Malignant ethmoid-sphenoidal tumors. 130 cases. Retrospective study].

We report on 130 ethmoidal cancers. 96 (74%) were adenocarcinomas (ADKE). 110 were operated upon between 1984 and 1996: 9.1% T1 + T2, 27.7% T3, 36.2% T4a, 27% T4b. Neoadjuvant chemotherapy was administered in 93 patients (76 ADKE). Combined surgical route was performed 103 times, sub-fronto-orbito-nasal (SFON) route 7 times. Post-operative radiotherapy was performed in 36 patients. Complete clinical and radiological response to chemotherapy was noted in 21.5% of cases (23% of ADKE). Post-operative mortality concerned one patient who died from a pulmonary embolism during the third post-operative week. Morbidity included: 3 transient clinical rhinorrheas, 5 meningitis (one of which was responsible for heavy psycho-intellectual disability), 4 deep suppurations associated with osteitis of the bone flap and two superficial suppurations. 44 patients had a local recurrence (10 ADKE). No recurrence appeared in complete chemoresponders. Systematic preservation of intra-orbital contents did not increase the risk of local failure. Eleven patients (4 ADKE) developed cervical nodes and/or systemic metastasis. Death occurred after a mean of three months following the diagnosis of metastasis. Survival rate was: 60% at 3 years, 51.5% at 5 years, 32.5% at 10 years. ADKE survival rate was: 55% at 3 years, 51.5% at 5 years, 23% at 10 years. Survival ws related to tumoral extension: 75% at 5 and 10 years for T3, 45% at 5 years and 38% at 10 years for T4a, 40% at 3 years and null at 5 years for T4b, 5 and 10 years survival rate of complete chemoresponders are 100% whatever the tumour. Prognosis remained poor for epidermoid carcinomas (survival rate: 36% at 3 years, 0% at 5 years) and for melanomas (mean survival: 19.6 months). Post-operative radiotherapy should be indicated for large tumors T3, T4a and T4b).

Adenocarcinoma↗
PubMed1997

[Stereotaxic technics and clinical neurosurgery].

Stereotactic methodology developed at Sainte-Anne Hospital Center from 1947 is based on the application of a simple spatial geometry-the Talairach Ac-Pc reference system-to the cranial volume and the identification of any anatomical structure or brain lesion within this volume. Now upgraded with modern imaging techniques, this methodology is the ground for multiple applications in functional as well as lesional neurosurgery and is now a a part of the daily neurosurgical practice at Sainte-Anne Hospital. Stereotactic procedures include three steps: first, the identification of one or several target-volumes through stereotactic imaging acquisition: CT, MRI and conventional stereoscopic angiography; second, the image treatment on a dedicated workstation for stereotactic coordinates determination and surgical planning; third, the surgical procedure itself and its control. The most frequent applications for stereotactic methodology are: image-guided stereotactic biopsies of brain tumors, in order to obtain tissue pathological diagnosis and spatial configuration; linac-based radiosurgery of arterio-venous malformations and tumors with high energy collimated beams converging towards a simple or complex target volume; surgery for partial drug-resistant epilepsy including depth electrode implantation for stereo-electroencephalography and epileptogenic cortex resection; stereotactic image-guided resection of superficial or deep-seated tumors or vascular malformation; Rhenium 186 intracavitary irradiation of cystic tumors such as craniopharyngiomas.

Biopsy↗
PubMed1997

[Stereotaxic radiotherapy of cerebral arteriovenous malformations: the role of neuroradiology].

The therapeutic approach to cerebral arteriovenous malformations has been modified with the availability of stereotactic radiosurgery, initially, the main indications of radiosurgery were limited, non surgical arteriovenous malformations. Indications are now much more diverse. Imaging plays an important role in the radiosurgical management of arteriovenous malformations and its evaluation. In this review, the different roles of neuroimaging are discussed; characterization of malformations, choice of the best indications, role of embolization, delimitation of the target, evaluation of results and complications of radiosurgery.

Cerebral Angiography↗
PubMed1996

Expression of adhesion molecules is specific and time-dependent in cytokine-stimulated endothelial cells in culture.

The time course of expression of the adhesion molecules E-selectin, VCAM-1, ICAM-1 and PECAM-1 was studied in interleukin-1 beta-stimulated human umbilical vein cells (HUVEC) and the subcellular sites of synthesis were determined by means of fluorescence immunohistochemistry. The maximal number of cells labelled for E-selectin was observed at 2-4 h, for VCAM-1 at 4-8 h and ICAM-1 at 6-72 h. At 8 h, E-selectin and VCAM-1 started to disappear, but ICAM-1-positive cells persisted. PECAM-1 was constitutively expressed. De novo synthesis for E-selectin started at 1 h and for both, VCAM-1 and ICAM-1 at 1.5-2 h. Maximal synthetic activity was observed at 2.5-4 h for E-selectin and at 4-6 h for VCAM-1 and ICAM-1; thereafter, synthesis slowly decreased. Transport granules occurred at 1.5 h for E-selectin and 4 h for VCAM-1; they were absent for ICAM-1. Diffuse cellular and membrane labelling indicative of the functional activity of the adhesion molecules began at 2-4 h for E-selectin, and 4 h for VCAM, but was constitutively present for ICAM-1. In conclusion, each adhesion molecule shows a specific time-dependent course of appearance and disappearance in interleukin-1 beta-stimulated HUVECs in accordance with their physiological role in vivo. These morphological results confirm data obtained by flow cytometry and Western blotting, but they provide new information about the behaviour of individual cells with regard to the sites of synthesis and cellular localization of the adhesion molecules.

Antigens, Differentiation, Myelomonocytic↗
PubMed1996

Intraspinal meningiomas: review of 54 cases with discussion of poor prognosis factors and modern therapeutic management.

INTRODUCTION: Intraspinal meningiomas account for 25%-46% of primary spinal cord tumors. Technical advances in magnetic resonance imaging (MRI) and surgical procedures (ultrasonic cavitation aspirators [CUSA], lasers) have brought about better clinical results. In spite of these new techniques, a small percentage of patients still present with poor postoperative results and/or a recurrence. The authors tried to determine which data could influence clinical outcome and what therapeutic modalities could limit recurrence rate. MATERIALS AND METHODS: We reviewed 54 patients who from 1963 to 1994, each had surgery for an intraspinal meningioma. There were 43 females and 11 males, aged 8 to 85 years old. Thirty-six (66.6%) patients were ambulatory on admission; only 2 presented with a paraplegia. Tumor location was cervical in 10 cases, thoracic in 43 cases, lumbar in 1 case. Forty-seven tumors were intradural, 5 epidural, 2 epidural and intradural. Thirty patients underwent a myelography, 10 a computed tomography (CT) scan, and 14 an MRI. Twenty-three spinal angiographies were performed before surgery. Complete removal was achieved in 50 patients (92.6%). Ultrasonic cavitation was used 10 times for debulking the tumor, and laser was used in 12 surgical procedures to perform hemostasis of the meningioma and to coagulate the dural attachment. RESULTS: The majority of the neoplasms were meningothelial (N = 24) or psammomatous (N = 11). No mortality was noted. Morbidity concerned five patients: two pulmonary embolisms, one definitive paraplegia, one transient deficit, and one epidural suppuration, which necessitated a second operation. Mean follow-up was 28 months. Final functional results were very good in 85% and good in 13%; one patient (2%) worsened. Two recurrences were noted: one with clinical signs and the other with only CT-scan modifications. Both patients underwent complementary radiotherapy. DISCUSSION AND CONCLUSION: The authors discuss factors influencing functional results. Sex, pregnancy, pathologic diagnosis, and recurrence do not seem to have any influence. Calcification of the meningioma, as well as an anterior dural attachment, are pejorative factors. They insist on preoperative angiography and point out the advantage of using a CUSA and/or a laser to debulk and coagulate the tumor itself and its dural attachment. They propose radiation therapy as an adjuvant treatment or an alternative to reoperation, which could be hazardous for some patients when, for instance, a recurrence is located in a critical area or when the patient's general status is fragile.

Adolescent↗