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F Roux

Publications and source records attributed to F Roux.

At least 19 recordsLinked to original sources
PubMed2003

[Sclerosing cholangitis as a complication of Langerhans'cell histiocytosis].

INTRODUCTION: Langerhans'cell histiocytosis is a rare and mainly pediatric disease. Patients with hepatic involvement usually have a disseminated form of the disease, with poor prognosis. Sclerosing cholangitis can occur in 10 to 15% of multivisceral Langerhans'cell histiocytosis. We report the case of a 56-years-old patient who developed sclerosing cholangitis 12 years after the diagnosis of Langerhans'cell histiocytosis. EXEGESIS: A 56-years-old man was admitted because of rapid general health impairment with epigastric pain. He was diagnosed as having Langerhans'cell histiocytosis 12 years ago because of a diabetes insipidus. Lungs were involved and during follow-up vertebral osteocondensation also developed. However, Langerhans'cell histiocytosis was clinically silent at the time of admission, without any treatment. Biologically, cholestasis and inflammation were noted. Digestive radiological investigations (echo-endoscopy, CT-scan, MRI) showed homogenous hepatomegaly and a diffuse infiltration of intra and extrahepatic bile ducts. Liver biopsy yielded the diagnosis of sclerosing cholangitis. Clinical and biological improvement occurred with oral corticosteroids (at 12 months after sclerosing cholangitis diagnosis). CONCLUSION: Sclerosing cholangitis is a potential complication of Langerhans'cell histiocytosis, mainly in its multivisceral form. It can occur at a median of 2 years after diagnosis in children, but occasionally much later in adults, whereas Langerhans'cell histiocytosis seems quiescent. Diagnosis is supported by radiological investigations and liver biopsy. As no drug therapy appears clearly effective, liver transplantation must frequently be considered in these patients.

Abdominal Pain↗
PubMed2001

Factor(s) released by glucose-deprived astrocytes enhance glucose transporter expression and activity in rat brain endothelial cells.

Glucose transporter (GLUT) expression and regulation were studied in rat brain endothelial cells in primary culture (RBEC) and in immortalised RBE4 cells. Immunoblotting analysis showed a low expression of the endothelium-specific GLUT1 in RBEC and RBE4 cells compared to isolated brain capillaries. RBEC and RBE4 cells also expressed the GLUT3 isoform, whereas it was not present in isolated brain capillaries. No change in GLUT expression was observed in endothelial cells treated with astrocyte-conditioned medium. However, treatment with conditioned medium obtained from glucose-deprived astrocytes increased endothelial GLUT1 expression and glucose uptake. These results suggest that astrocytes submitted to hypoglycaemic conditions may release factor(s) that increase glucose uptake through the blood-brain barrier.

Animals↗
PubMed2001

Does aging affect the allocation of visual attention in global and local information processing?

The earliest studies of Navon (1977) showed that in certain conditions the visual perception of hierarchical stimuli generates a global precedence effect. This hypothesis is based on the joint occurrence of two effects: a response time (RT) advantage for identifying global targets and interference by global distractors when responding to a local target. The aim of the present study was to determine the involvement of attentional mechanisms and whether certain aspects are specifically altered by normal aging. In a selective-attention task, a complete global precedence effect was found for young and old subjects. However, for the old subjects, global interference on local identification was more pronounced than for the young subjects. In a divided-attention task, the RT advantage was affected by attention shifts between global and local forms for both young and old subjects, but the global interference effect did not change.

Adult↗
PubMed2001

Lamproglena hoi n.sp. (Copepoda: Lernaeidae) from two yellowfish hosts, Barbus marequensis and Barbus polylepis, caught in a river in Mpumalanga, South Africa.

Lamproglena hoi n.sp. species was collected from the gill filaments of largescale yellowfish, Barbus marequensis A. Smith, 1841 and smallscale yellowfish, Barbus polylepis Boulenger, 1907 from the Spekboom River, Mpumalanga, South Africa. The genus Lamproglena is characterized. Morphological features of L. hoi are described and illustrated by means of drawings and scanning electron micrographs. This species is also compared with congener species described from other Barbus spp.

Animals↗
PubMed2000

Interactions of racemic mefloquine and its enantiomers with P-glycoprotein in an immortalised rat brain capillary endothelial cell line, GPNT.

The brain distribution of the enantiomers of the antimalarial drug mefloquine is stereoselective according to the species. This stereoselectivity may be related to species-specific differences in the properties of some membrane-bound transport proteins, such as P-glycoprotein (P-gp). The interactions of racemic mefloquine and its individual enantiomers with the P-glycoprotein efflux transport system have been analysed in immortalised rat brain capillary endothelial GPNT cells. Parallel studies were carried out for comparison in human colon carcinoma Caco-2 cells. The cellular accumulation of the P-glycoprotein substrate, [(3)H]vinblastine, was significantly increased both in GPNT cells and in Caco-2 cells when treated with racemic mefloquine and the individual enantiomers. In GPNT cells, the (+)-stereoisomer of mefloquine was up to 8-fold more effective than its antipode in increasing cellular accumulation of [(3)H]vinblastine, while in Caco-2 cells, both enantiomers were equally effective. These results suggest that racemic mefloquine and its enantiomers are effective inhibitors of P-gp. Furthermore, a stereoselective P-glycoprotein inhibition is observed in rat cells but not in human cells. The efflux of [(14)C]mefloquine from GPNT cells was decreased when the cells were incubated with the P-gp modulators, verapamil, cyclosporin A or chlorpromazine, suggesting that MQ could be a P-gp substrate.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Functional expression of P-glycoprotein and multidrug resistance-associated protein (Mrp1) in primary cultures of rat astrocytes.

Although it has been well established that the drug efflux pump P-glycoprotein (P-gp) protects the brain against the entry of cytotoxic drugs, its real in situ localization, i.e., at brain capillary endothelial cells or on astrocyte foot processes, is still controversial. The aim of this study was to compare the expression of P-gp and of multidrug resistance-associated protein (Mrp1), another drug efflux pump, in cultured neonatal rat brain astrocytes and in cultured brain capillary endothelial cells. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that the mdr1b gene was preferentially expressed in astrocytes, whereas both mdr1a and mdr1b mRNA were detected in endothelial cells. Moreover, the mrp1 gene encoding Mrp1 was expressed in both cell types. Western blotting analysis revealed higher expression of P-gp in endothelial cells as compared with astrocytes, but higher expression of Mrp1 in astrocytes. Moreover, P-gp and Mrp1 expression was not modified in more differentiated astrocytes obtained when cultured with db-cAMP for 48 hr. Our functional analysis of P-gp showed a modest effect of P-gp modulators (CsA, verapamil, PSC 833) on the uptake of colchicine (a substrate of P-gp) by astrocytes, whereas they increased by about 50% the uptake of vincristine (a common substrate of P-gp and MRP) by astrocytes. MRP modulators (genistein, probenecid, and sulfinpyrazone) did not modify the uptake of colchicine but increased that of vincristine with a major effect found for sulfinpyrazone. Moreover, indomethacin, probenecid, and sulfinpyrazone increased the uptake of fluorescein (a substrate of MRP but not of P-gp). Taken together, our results provide the first biochemical and functional evidence supporting the expression of P-gp and Mrp1 in rat cultured astrocytes.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Sleep-related breathing disorders and cardiovascular disease.

Sleep-related breathing disorders, ranging from habitual snoring to the increased upper airway resistance syndrome to sleep apnea, are now recognized as major health problems. The majority of patients have excessive daytime sleepiness and tiredness. Neuropsychological dysfunction results in poor work performance, memory impairment, and even depression. Until recently, the coexistence of cardiovascular and cerebrovascular diseases with sleep-related breathing disorders was thought to be the result of shared risk factors, such as age, sex, and obesity. However, in the past 5 years several epidemiologic studies have demonstrated that sleep-related breathing disorders are an independent risk factor for hypertension, probably resulting from a combination of intermittent hypoxia and hypercapnia, arousals, increased sympathetic tone, and altered baroreflex control during sleep. Sleep apnea may lead to the development of cardiomyopathy and pulmonary hypertension. Early recognition and treatment of sleep-related breathing disorders may improve cardiovascular function.

Cardiovascular Diseases↗
PubMed2000

High-Resolution Fourier Spectrometry of the (14)N(+)(2) Ion.

Rotational analyses of the B(2)Sigma(+)(u) --> X(2)Sigma(+)(g) system of the (14)N(+)(2) molecule have been extended to include the vibrational levels up to v' = 4. Spectral data from 20 bands obtained from high-resolution Fourier transform spectrometry of a hollow-cathode and a Pointolite lamp were included in the analysis. A global deperturbation yielded molecular parameters of the highly perturbed B(2)Sigma state and interaction parameters A(2)Pi(u) approximately B(2)Sigma(u) with a standard deviation of 0.011 cm(-1). Rotational term values of the B(2)Sigma(+) state were also determined. New perturbations in the B(2)Sigma(+) (v = 0) level have been observed at N approximately 85 and N approximately 96. Copyright 2000 Academic Press.

Journal Article↗
PubMed2000

Notch4 and Jagged-1 induce microvessel differentiation of rat brain endothelial cells.

The mouse Notch4 gene is expressed specifically in endothelial cells. Notch4/int-3, a truncated form of Notch4, acts as a constitutive activated Notch receptor. We used rat brain microvessel endothelial cells (RBE4) to study the role of Notch4 and Jagged-1 in endothelial cell differentiation. Both Notch4/int-3 and Jagged-1 were able to induce microvessel-like structures with morphological and biochemical properties similar to brain endothelial microvessels. Ectopic expression of full-length Notch4 did not effect RBE4 cells. Activation of the Notch signal transduction pathway was measured by the induction of endogenous Notch4 and Jagged-1 genes and of Jagged-1 proteins. The observed morphological changes to RBE4 cells correlated with endogenous Notch4 and Jagged-1 gene activation. Our observations demonstrate that Notch signaling can promote endothelial cell differentiation and morphogenesis.

Animals↗
PubMed2000

The attendance cycles of the Cory's Shearwater Calonectris diomedea borealis on Selvagem Grande.

In the Cory's Shearwater Calonectris diomedea borealis of Selvagem Grande (30 degrees 09'N, 15 degrees 52'W), the visits the birds pay to their colonies are cyclic throughout the breeding period. The number of visitors varies regularly between a minimum and a maximum following a sinusoid, the half-period of which is 4.8 +/- 1.5 d (2-8 d). No variation exists according to the status of the birds (breeders or non-breeders) or to the stage of the breeding cycle (pre-egg, incubation or chick rearing) and moon phases have no influence. Among Procellariids, such attendance cycles are related to the length of the pre-egg stage. They are absent when it is short (less than 50 d), present when it is long (more than 60 d), and indifferently present or absent when it is intermediate (50-60 d). Considering the comparative scarcity of the visits of the birds to the colonies during the pre-egg stage, these cycles are likely to play a part essentially in the synchronisation of individuals in colonies and of mates in pairs.

Animals↗
PubMed2000

Assessment of the in vitro and in vivo properties of a (99m)Tc-labeled inhibitor of the multidrug resistant gene product P-glycoprotein.

Overexpression of P-glycoprotein (Pgp), which is present in the plasma membrane of various tumor cells and in several normal cell types, contributes to the multidrug resistance (MDR) phenotype of many human cancers. As a prerequisite for therapy, the expression of Pgp must be studied. The available clinical radiopharmaceuticals for studying the expression of Pgp include the lipophilic (99m)Tc cations (sestamibi, tetrofosmin) as well as [(99m)Tc]Q57, [(99m)Tc]Q58, and [(99m)Tc]Q63. Here we describe the in vitro and in vivo properties of the structurally different complex (3-thiapentane-1, 5-dithiolato)[[N-(3-phenylpropyl)-N-2(3-quinazoline-2, 4-dionyl)-ethyl]amino-ethylthiolato¿ oxotechnetium(V) ((99/99m)Tc1) as a potential inhibitor of Pgp. (99)Tc1 enhances the net cell accumulation of Pgp substrates [(3)H]vinblastine, [(3)H]vincristine, [(3)H]colchicine, [(99m)Tc]sestamibi, and [(99m)Tc]tetrofosmin in rat brain endothelial cells (RBE4), an immortalized endothelial cell line that expresses Pgp. In addition, the cell accumulation of (99m)Tc1 could be increased by verapamil and reserpine, which are known Pgp inhibitors. A multitracer approach was used to study the side effects of (99)Tc1 on cell metabolism. The cells were simultaneously incubated with [(99m)Tc]sestamibi, 2-[(18)F]fluoro-2-deoxyglucose ([(18)F]FDG), and various (3)H-labeled tracers. Two-dimensional scatter plots of [(99m)Tc]sestamibi uptake/[(18)F]FDG uptake show typical changes of known Pgp inhibitors including (99)Tc1. The effects of (99)Tc1 on the in vivo distribution of [(99m)Tc]sestamibi and [(18)F]FDG in rats also are comparable with the effects of verapamil, an established Pgp inhibitor and calcium channel blocker. We conclude that (99/99m)Tc1 is a transport substrate and a potential inhibitor of Pgp. Our approach may be useful in the design of further radiotracers with specificity to Pgp.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Functional expression of the serotonin transporter in immortalized rat brain microvessel endothelial cells.

There is evidence from recent studies that the brain endothelium (of capillaries and/or larger vessels) may serve as a specific target for serotonin [5-hydroxytryptamine (5-HT)]. This neurotransmitter is expected to be involved in the regulation of the blood-brain barrier (BBB) permeability and/or of the cerebral blood flow via receptor-mediated mechanisms. Effective control of these processes depends on a speedy uptake and metabolism of released 5-HT molecules. To realize this, a similar mechanism of 5-HT uptake as in brain may exist at the BBB. In this study, we have demonstrated using RT-PCR that 5-HT transporter mRNA is present in the brain endothelium and that a saturable transport system for 5-HT is functionally expressed in immortalized rat brain endothelial cells (RBE4 cells). These cells take up [3H]5-HT by an active saturable process with a Km value of 397 +/- 64 nmol/L and a transport capacity of 51.7 +/- 3.5 pmol x g(-1) x min(-1). The 5-HT uptake depends on Na+, as indicated by the replacement of NaCl by LiCl. The 5-HT uptake was sensitive to specific 5-HT transport inhibitors such as paroxetine, clomipramine, fluoxetine, and citalopram but not to inhibitors of the vesicular amine transporter such as reserpine or tetrabenazine. Our results demonstrate that cerebral endothelial cells are able to participate actively in the removal and metabolism of the released 5-HT, which supports the concept of direct serotoninergic regulation of the BBB function.

Animals↗
PubMed2000

IL-13 stimulates vascular endothelial cell growth factor and protects against hyperoxic acute lung injury.

Hyperoxia is an important cause of acute lung injury. To determine whether IL-13 is protective in hyperoxia, we compared the survival in 100% O(2) of transgenic mice that overexpress IL-13 in the lung and of nontransgenic littermate controls. IL-13 enhanced survival in 100% O(2). One hundred percent of nontransgenic mice died in 4-5 days, whereas 100% of IL-13-overexpressing mice lived for more than 7 days, and many lived 10-14 days. IL-13 also stimulated VEGF accumulation in mice breathing room air, and it interacted with 100% (2) to increase VEGF accumulation further. The 164-amino acid isoform was the major VEGF moiety in bronchoalveolar lavage from transgenic mice in room air, whereas the 120- and 188-amino acid isoforms accumulated in these mice during hyperoxia. In addition, antibody neutralization of VEGF decreased the survival of IL-13-overexpressing mice in 100% (2). These studies demonstrate that IL-13 has protective effects in hyperoxic acute lung injury. They also demonstrate that IL-13, alone and in combination with 100% (2), stimulates pulmonary VEGF accumulation, that this stimulation is isoform-specific, and that the protective effects of IL-13 are mediated, in part, by VEGF.

Animals↗
PubMed1999

Chemical reactivity in matrix-assisted laser desorption/ionization mass spectrometry

During the control of a multistep organic synthesis on a soluble polymer (PEG) by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, a chemical reactivity was encountered when the matrix was acidic, for the samples where the amino moiety of the anchored compounds was protected as a Schiff base. Such imine hydrolysis was proven to be solely mediated by the acidic matrix during analyses since the expected protected structures were detected when the experiments were duplicated with a non-acidic matrix. Even if MALDI mass spectrometry was found to be more convenient than electrospray ionization mass spectrometry for the monitoring of liquid phase organic syntheses, the chemical reactivity imparted by the use of a matrix must be taken into account to avoid erroneous spectra interpretations. Copyright 1999 John Wiley & Sons, Ltd.

Journal Article↗
PubMed1999

Kinetics of postbiopsy levels of serum free prostate-specific antigen and percent free prostate-specific antigen.

OBJECTIVES: We evaluated the effects of transrectal ultrasound-guided biopsy of the prostate on serum total and free prostate-specific antigen (PSA) and the free/total PSA ratio and factors affecting variations in PSA levels. METHODS: Serum total and free PSA levels and the free/total PSA ratio were determined in 48 men (mean age 66+/-7 years) before and 1 hour, 8 days, and 30 days after prostate biopsy. At least six cores were taken using a biopsy gun with an 18-gauge needle. The coefficient of variation of PSA was calculated as the postbiopsy/prebiopsy PSA ratio. Changes in PSA levels and the coefficient of variation were studied. RESULTS: Fifteen (31%) of 48 men had adenocarcinoma on biopsy. Total and free PSA values were significantly increased 1 hour and 8 days after biopsy, and both returned to baseline 30 days after biopsy. The free/total PSA ratio was significantly increased (55%) 1 hour after biopsy and significantly decreased (12%) 8 days after biopsy. Thirty days after biopsy, the median of the free/total PSA ratio (18%) was not significantly different from the prebiopsy ratio (16%). The median of the coefficient of variation of the free/total PSA ratio was 3, 0.7, and 1 at 1 hour, 8 days, and 30 days after biopsy, respectively. Age, prostate volume, number of cores, and digital rectal examination and histologic findings were not significantly associated with variation in percent free PSA. Variation in percent free PSA at day 8 was associated with prebiopsy total PSA value and the free/total PSA ratio. CONCLUSIONS: Prostate biopsy dramatically alters the percent free PSA. The free/total PSA ratio was decreased 8 days after biopsy and returned to prebiopsy levels in 75% of patients at 1 month after biopsy. Measurement of free PSA levels and the free/total PSA ratio should not be done within 4 weeks of prostate biopsy.

Adenocarcinoma↗
PubMed1999

Effect of digital rectal examination on serum complexed and free prostate-specific antigen and percentage of free prostate-specific antigen.

OBJECTIVES: To evaluate the effects of digital rectal examination (DRE) on serum total, calculated complexed, and free prostate-specific antigen (PSA) and the free/total PSA ratio and factors affecting variations of PSA. METHODS: Serum total and free PSA and the percent free PSA ratio were determined in 91 urologically referred men (mean age 64 +/- 9 years) before and 30 minutes after DRE, with the Hybritech Tandem-R assay. Complexed PSA was calculated as the difference between total and free PSA. DRE effects on PSA were analyzed comparing pre-DRE and post-DRE values and by calculating the difference between pre-DRE and post-DRE PSA and the post/pre-DRE geometric ratio as a coefficient of variation. RESULTS: Thirty minutes after DRE, the increase in total, calculated complexed, and free PSA and the percent free PSA ratio was statistically significant. The difference between post-DRE and pre-DRE values of serum total, calculated complexed, and free PSA and percent free PSA was +0.9, +0.3, and +0.6 ng/mL and + 10%, respectively. The post/pre-DRE ratio of serum total, calculated complexed, and free PSA and percent free PSA was x1.5, x1.22, and x2.5 and x1.7, respectively. Patient age, DRE findings, prostate volume, prostate histologic features, and the initial value of total PSA had no statistically significant effect on the change of percent free PSA after DRE. The initial percent free PSA had a statistically significant effect on the change of percent free PSA after DRE. The values of calculated complexed PSA before and after DRE were significantly higher in patients with a prostate volume greater than 40 cc, prostate cancer on biopsy, and an initial free/total PSA ratio greater than 18%. CONCLUSIONS: In this study, DRE significantly increased total, calculated complexed, and free PSA and percent free PSA. The increase of PSA immediately after DRE was mainly due to the increase of free PSA. The change of percent free PSA after DRE depended on the initial percentage of free PSA. Complexed PSA seems less sensitive to DRE, and its changes after DRE were clinically modest. Free PSA measurement should be done before DRE and percent free PSA should be used only when the venipuncture is done before the DRE.

Aged↗