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R Bordet

Publications and source records attributed to R Bordet.

At least 55 records · Page 3Linked to original sources
PubMed1997

Bronchial arteries in the pig before and after permanent pulmonary artery occlusion.

RATIONALE AND OBJECTIVES: The authors study the bronchial arteries in the adult pig before and after pulmonary artery occlusion. METHODS: The bronchial artery anatomy was analyzed on postmortem aortograms in six pigs in group 1. In 20 animals in group 2, the left diaphragmatic lobar pulmonary artery (DLPA) was proximally (n = 12), medially (n = 5), or distally (n = 3) occluded via angiographic procedures; an unintentional embolization of coils in the right DLPA led to an incomplete pulmonary arterial occlusion. Eight to 12 weeks later, postmortem bronchial angiograms and pathologic studies were performed systematically in group 2. RESULTS: Outcomes in group 1 were: (A) a common trunk to the right and left bronchial arteries found in five animals, and (B) bronchopulmonary anastomoses found in the five lungs optimally injected. Outcomes in group 2 were: (A) the absence of pulmonary infarct and the development of a collateral bronchial supply were constant in the left lung; (B) the left DLPAs were patent beyond the coils and opacified via bronchopulmonary anastomoses; (C) dilated subpleural bronchial arteries were constant in the interlobular septa of the lung parenchyma devoid of pulmonary arterial perfusion; (D) the right bronchial arteries were normal after incomplete pulmonary artery occlusion. CONCLUSIONS: Because of an anastomosed dual circulation, the pig is a reliable experimental model for interventional and surgical procedures.

Animals↗
PubMed1997

Effects of octreotide on experimental neurogenic orthostatic hypotension in anaesthetized dogs.

This paper investigates the effects of octreotide (0.1 mg/kg, subcutaneous) on cardiovascular adaptation during head-up tilt test in an experimental model of neurogenic orthostatic hypotension (OH) obtained by chronic sinoaortic denervation in anaesthetized dogs. Blood pressure (BP), heart rate (HR), spectral variability (Fast Fourier transformation on 512 consecutive points, delta t: 2 Hz) and plasma catecholamine levels were measured in a double blind cross-over randomized study versus placebo, in supine position and during a head-up tilt test (80 degrees, 10 min) in six sinoaortic denervated and six control (normal) dogs. In normal dogs, head-up tilt test significantly increased HR and diastolic blood pressure (DBP). Plasma noradrenaline levels and energy of the low frequency band (40-150 mHz) of systolic blood pressure (SBP) significantly increased whereas the energy of the low frequency band of HR significantly decreased. Placebo and octreotide failed to modify supine and head-up tilt values of the measured parameters (except the value of low frequency band of SBP, which increased after octreotide). In sinoaortic denervated dogs, supine values of BP, HR and plasma noradrenaline levels were significantly higher than in controls whereas the energy of the low frequency spectral band of HR and SBP was similar to controls. Head-up tilt test induced a dramatic decrease in BP. HR, plasma noradrenaline levels and energy of the low frequency band of SBP and HR remained unchanged during head-up tilt tests. Neither supine nor head-up tilt values of these parameters were modified 45 min after octreotide or placebo administration. These results show that sinoaortic denervation is a reproducible model of OH characterized by a lack of activation of sympathetic efferent pathways during head-up tilt tests. Octreotide at the dose used remains ineffective to prevent the fall in BP under these experimental conditions.

Anesthesia↗
PubMed1996

Sympathetic skin response and R-R interval variability in multiple system atrophy and idiopathic Parkinson's disease.

We compared autonomic function in patients with multiple system atrophy (MSA) or with idiopathic Parkinson's disease (IPD) by measuring sympathetic skin response (SSR) and R-R interval variability (RRIV). SSR was investigated in 26 patients (13 with MSA and 13 patients with IPD). RRIV during deep breathing, Valsalva maneuver, and on standing was investigated in 20 patients (nine with MSA and 11 with IPD). MSA and IPD patients had similar age, illness duration, and therapy. Abnormal SSR was more frequent in MSA (69%) than in IPD (7.7%; x2, 10.4; p < 0.002). RRIV during deep breathing and the Valsalva maneuver was lower in MSA than in IPD (p = 0.02). RRIV during standing up was not significantly different in IPD and MSA. These differences between MSA and IPD may be due to more severe and widespread autonomic disturbance in MSA, related to more severe neuropathologic involvement of the autonomic nervous system. SSR and RRIV may aid in the differential diagnosis of parkinsonism and help to exclude from clinical trials MSA patients clinically misdiagnosed as having IPD.

Aged↗
PubMed1996

Lack of relation between genetic polymorphism of cytochrome P-450IID6 and sporadic idiopathic Parkinson's disease.

We investigated genetic polymorphism of the cytochrome P-450 CYP2D6 gene from white patients with idiopathic Parkinson's disease (IPD). The mutations of the CYP2D6 gene associated with the poor metabolizer (PM) phenotype of the debrisoquine/sparteine polymorphism were analyzed in DNA of 130 IPD patients by a polymerase chain reaction (PCR)-based DNA amplification combined with Xba I restriction fragment length polymorphism (RFLP) analysis in 105 patients. Another mutation located in exon 6 was analyzed by Hha I RFLP in 94 IPD patients. The frequencies of the different CYP2D6 gene mutations were compared to the frequencies in sex- and age-matched white control population with chronic bronchitis. The rate of genotypically defined PM and the frequencies of the different mutations were not significantly different in IPD patients and controls. These results fail to confirm the previously reported results concerning CYP2D6 gene mutations in IPD. These equivocal results might be related to methodologic problems. However, other hypotheses have been suggested: impairment of neuronal CYP 2D6 expression, transient modification of CYP 2D6 phenotype, or linkage of CYP2D6 gene to the candidate gene locus directly involved in IPD.

Aged↗
PubMed1996

[Effects of octreotide on experimental orthostatic neurogenic hypotension].

The synthetic somatostatin analogue, octreotide, has recently been proposed for the treatment of both postprandial and orthostatic hypotension (OH) in humans with autonomic failure related to multiple system atrophy (MSA) or diabetes mellitus. However, pharmacodynamic data are not still available in experimental models of orthostatic hypotension. We investigated in a model of neurogenic orthostatic hypotension, obtained by chronic sinoaortic denervation (SAD) in chloralose-anaesthetized dogs, the effects of octreotide (0.1 mg/kg, subcutaneous route) during a double-blind cross-over study vs placebo. Blood pressure (BP) and heart rate (HR) average values, SBP and HR short-term variabilities (using fast Fourier transformation) in both low (LF: 50-150 mHz) and high frequency range (respiratory rate +/- 50 mHz) and plasma noradrenaline (NA) levels (HPLC) were measured in supine position and during head-up tilt test (HUT: 80 degrees, 10 min) before and 45 min after drug administration. In controls, as expected, head-up tilt test induced a significant increase in DBP (+14 +/- 8 mmHg), HR (+36 +/- 21 beat/min), NA (296 +/- 118 vs 141 +/- 63 pg/ml), SBP-LF (25 +/- 5 vs 14 +/- 3%) whereas HR-HF significantly decreased. The changes during head-up tilt test were not modified after placebo or octreotide administration. In SAD dogs, head-up tilt test elicited a dramatic fall in SBP (-74 +/- 39 mmHg), DBP (-20 +/- 15 mmHg) without any significant change in HR (-5 +/- 12 beat/min), NA (708 +/- 213 vs 606 +/- 331 pg/ml), SBP-LF (16 +/- 3 vs 16 +/- 3%), HR-HF (8 +/- 2 vs 7 +/- 1%). Octreotide or placebo failed to significantly modify any of the measured parameters during head-up tilt test performed 45 min after drug administration. At the dose used, octreotide elicited a 80% decrease in insulin plasma levels after 45 min in both normal and SAD dogs. These results suggest that 1) this experimental model of orthostatic hypotension in SAD dogs is reproductible and can be used to investigate the pharmacological effects of antihypotensive drugs, 2) cardiovascular and biochemical characteristics of the SAD model are similar to those observed in MSA and 3) octreotide, in these experimental conditions, is not able to correct the BP fall during head-up tilt test.

Animals↗
PubMed1995

Octreotide effects on orthostatic hypotension in patients with multiple system atrophy: a controlled study of acute administration.

In nine patients with orthostatic hypotension due to multiple system atrophy, the effects of octreotide (100 micrograms s.c.), a somatostatin analogue, on blood pressure (BP), heart rate (HR), and norepinephrine (NE) plasma levels after 60 degrees head up tilt test were evaluated by a randomly controlled study. Octreotide increased supine BP, tilt-test duration (+28%), and delay to obtain minimal BP during the 60 degrees head up tilt (+50%). Octreotide changed neither HR nor NE plasma levels.

Aged↗
PubMed1995

[Demonstration of a specific profile of pathological Tau proteins in frontotemporal dementia cases].

We compared samples of different brain areas from patients with Alzheimer's disease (AD), progressive supranuclear palsy (PSP), controls subjects and from 4 patients who met the clinical and pathological criteria for frontotemporal dementia (FTD), using a Western blot analysis. We used polyclonal antibodies directed against Tau proteins and the monoclonal antibody AD2 for the immunodetection of the pathological Tau proteins which are the basic components of neurofibrillary degeneration. In the PSP and AD cases, we respectively detected the abnormal Tau proteins 64 and 69 and the Tau proteins 55, 64, and 69, systematically associated with bands and smears, corresponding to catabolic products or aggregates of these abnormal Tau proteins. In FTD cases, the abnormal Tau proteins 55, 64 and 69 were also detected in the frontal and temporal poles from the autopsied case and in the cortical biopsies. However, the profiles were different because smears and proteolytics products of Tau proteins were absent. There was no detection of abnormal Tau proteins in control brain homogenates and in biopsies from patients with other neurodegenerative disorders such as spongiform encephalopathies or primitive gliosis. These results demonstrate that pathological Tau proteins are produced during FTD degenerating process, despite the absence of neurofibrillary lesions.

Adult↗
PubMed1994

Genetic polymorphism of cytochrome P450 2D6 in idiopathic Parkinson disease and diffuse Lewy body disease.

We investigated genetic polymorphism of the cytochrome P450 CYP 2D6 gene in 105 caucasian patients with idiopathic Parkinson's disease (IPD) and 15 patients with diffuse Lewy body disease (DLBD). The mutations of the CYP 2D6 gene associated with the poor metabolizer (PM) phenotype of the debrisoquine/sparteine polymorphism were analyzed in DNA by a polymerase chain reaction (PCR)-based DNA amplification combined with Xba I restriction fragment length polymorphism (RFLP) analysis. The rate of genotypically defined PM and the frequencies of the mutation D6-B were not significantly different in IPD and DLBD patients. This study fails to find a relationship between CYP 2D6 impairment and neuropathological lesions diffusion in IPD and DLBD. This study cannot exclude involvement of neuronal expression of CYP 2D6.

Aged↗
PubMed1994

Octreotide in the management of orthostatic hypotension in multiple system atrophy: pilot trial of chronic administration.

The aim of the study was to determine the potential effect of octreotide chronic administration on the functional prognosis of patients suffering from multiple system atrophy (MSA) with orthostatic hypotension (OH). Five patients received octreotide (100 micrograms s.c. injections t.i.d.) during 6 months in an open trial. Patients experienced functional improvement after 6 months of treatment. All of them continued to receive octreotide after the 6-month evaluation period (mean duration: 12 months).

Aged↗
PubMed1992

[From Parkinson's disease to Lewy body disease].

Lewy bodies are intraneuronal inclusions initially found in the pigmented brainstem nuclei of patients with Parkinson's disease. Their aspect varies according to their neuronal or cerebral situation. They have been a long time the hallmark of Parkinson's disease, but in recent years it has emerged that a small group of rare disorders or rare variants of common degenerative diseases are also sometimes associated with Lewy bodies in the nervous system. Pathological studies have also individualized a new disorder characterized by the presence of numerous Lewy bodies throughout the cerebral cortex and the brainstem: Lewy body disease. The clinical syndrome associates dementia, parkinsonian features, dysautonomia and motor neuron disease. The dementia is cortical in type and psychiatric symptoms such as agitation, hallucinations or delusions are frequent. The pathological features are nerve cell loss, diffuse Lewy bodies, and sometimes senile plaques. The origin of this disorder remains unclear, but it could be a primitive abnormality of neuronal cytoskeleton.

Alzheimer Disease↗
PubMed1992

[Hashimoto's encephalopathy: toxic or autoimmune mechanism?].

A 36-year-old woman presented with partial complex status epilepticus. Magnetic resonance imaging with T2-weighted sequences showed a high-intensity signal in the left posterior frontal area. Hashimoto's thyroiditis was then discovered. The disappearance of the high-intensity signal after corticosteroid therapy was suggestive of an autoimmune mechanism. However, improvement could be obtained only with a hormonal treatment, which supports the hypothesis of a pathogenetic role of the Tyrosine-Releasing Hormone (TRH).

Adult↗
PubMed1992

[Facial paralysis and chicken-pox].

Ten days after chicken-pox, a 24-year old man presented with a right facial palsy without meningitis. Albumino-cytologic dissociation in CSF--not observed in two other published cases--suggests an immune-mediated process. The patient was treated by prednisone and aciclovir. The upper facial muscles remained paretic 2 months after onset.

Acyclovir↗
PubMed1991

[Epidural angiolipoma and multiple familial lipomatosis].

In a 35-year old woman presenting familial multiple lipomatosis, spastic paraparesis developed and became worse under tetracosactide therapy. Signs of spinal cord compression at T3 were present. CT and MRI revealed a fat-containing epidural tumour (angiolipoma). The association of angiolipoma with familial multiple lipomatosis has not yet been reported. This association supports the theory that angiolipomas are hamartomatous lesions. The deterioration observed under tetracosactide suggests that iatrogenic epidural lipomatosis is due to the development of a pre-existing lipoma.

Adult↗