Showing papers by "University of Grenoble published in 1998"
TL;DR: The overall results favour the neurosurgical treatment of Parkinson's disease by stimulating the STn rather than the GPi, and the reduction of levodopa dosage in the STN group led to an indirect reduction of LID similar to that in theGPi group during activities of everyday life.
Abstract: The aim of this study was to compare, retrospectively, the value of chronic bilateral stimulation of the internal globus pallidus (GPi) and the subthalamic nucleus (STN) in patients with young onset Parkinson's disease. We selected 13 consecutive patients with similar characteristics at the time of surgery: age at onset < 40 years, disabling motor fluctuations (Hoehn and Yahr stage 4 or 5 in off-drug phases) and levodopa-induced dyskinesias (LID). Eight patients were operated on in the STN and five in the GPi. The Unified Parkinson's Disease Rating Scale (UPDRS), timed motor tests and a LID scale were compared in on- and off-drug conditions before surgery and 6 months after surgery on stimulation using the chronic electrical parameters found to improve best the motor state of the individual patient, without adverse effects. In off-drug phases, the motor score of the UPDRS was improved by 71% with STN stimulation and by 39% with GPi stimulation on average. This difference was statistically significant (P < 0.05). Whereas rigidity and tremor showed good improvement in both groups, the decrease in the akinesia score was more pronounced in the STN group. In the STN group, the improvement of all motor symptoms was very close, or equal, to the best levodopa response. Thus the levodopa test was predictive of outcome. The improvement in off-drug period motor handicap allowed a decrease in the levodopa-equivalent dose only in the STN group (-56%). The voltage, frequency and pulse width used for chronic stimulation were lower in the STN group. In the on-drug phases there was a marked improvement in LID in the GPi group, as measured by the dyskinesias score during an acute levodopa test, whereas there was only a small decrease in the STN group (P < 0.05). However, in the long term, the reduction of levodopa dosage in the STN group led to an indirect reduction of LID similar to that in the GPi group during activities of everyday life. In conclusion, the overall results favour the neurosurgical treatment of Parkinson's disease by stimulating the STN rather than the GPi.
583 citations
TL;DR: There are at least two different functional zones within the globus pallidus within the GPi, at the basis of a different pathophysiology of the cardinal symptoms of PD, which may explain the variable results of pallidal surgery reported in the literature and largely explain the paradox of PD surgery.
Abstract: We studied the effects--on parkinsonian signs, on levodopa-induced dyskinesias, and on levodopa response--of acute experimental high-frequency stimulation of the internal pallidum (GPi) during off-drug and on-drug phases. Thirteen quadripolar electrodes were evaluated in 8 patients with Parkinson's disease (PD). Stimulation of the most ventral contacts, lying at the ventral margin of or just below the GPi, led to pronounced improvement in rigidity and a complete arrest of levodopa-induced dyskinesias. The antiakinetic effect of levodopa was also blocked and the patients became severely akinetic. Stimulation of the most dorsal contacts, lying at the dorsal border of the GPi or inside the external pallidum, usually led to moderate improvement of off-drug akinesia and could also induce dyskinesias in some patients. When using an intermediate contact for chronic stimulation, a good compromise between these opposite effects was usually obtained, mimicking the effect of pallidotomy. We conclude that there are at least two different functional zones within the globus pallidus, at the basis of a different pathophysiology of the cardinal symptoms of PD. The opposite effects may explain the variable results of pallidal surgery reported in the literature and may also largely explain the paradox of PD surgery. A possible anatomical basis for these differential functional effects could be a functional somatotopy within the GPi, with the segregation of the pallidofugal fibers from the outer portion of the GPi, on one hand, forming the ventral ansa lenticularis and from the inner portion of the GPi, on the other hand, forming the dorsal lenticular fasciculus.
332 citations
TL;DR: Ten large European cities provided data on daily air pollution as well as mortality from respiratory and cardiovascular mortality, using Poisson autoregressive models that controlled for trend, season, influenza epidemics, and meteorologic influences to assess the short-term effects of air pollution.
Abstract: Ten large European cities provided data on daily air pollution as well as mortality from respiratory and cardiovascular mortality. We used Poisson autoregressive models that controlled for trend, season, influenza epidemics, and meteorologic influences to assess the short-term effects of air pollution at each city. We then compared and pooled the city-specific results in a meta-analysis. The pooled relative risks of daily deaths from cardiovascular conditions were 1.02 [95% confidence interval (CI) = 1.01-1.04] for a 50 microg/m3 increment in the concentration of black smoke and 1.04 (95% CI = 1.01-1.06) for an increase in sulfur dioxide levels in western European cities. For respiratory diseases, these figures were 1.04 (95% CI = 1.02-1.07) and 1.05 (95% CI = 1.03-1.07), respectively. These associations were not found in the five central European cities. Eight-hour averages of ozone were also moderately associated with daily mortality in western European cities (relative risk = 1.02; 95% CI = 1.00-1.03 for cardiovascular conditions and relative risk = 1.06; 95% CI = 1.02-1.10 for respiratory conditions). Nitrogen dioxide did not show consistent relations with daily mortality. These results are similar to previously published data and add credence to the causal interpretation of these associations at levels of air pollution close to or lower than current European standards.
209 citations
TL;DR: Fungal cell walls possess strong complexing properties, which make them valuable biosorbents to remove heavy metals from wastewaters.
Abstract: Fungal cell walls possess strong complexing properties, which make them valuable biosorbents to remove heavy metals from wastewaters. The binding mechanisms of Zn and Pb to Penicillium chrysogenum ...
185 citations
TL;DR: Some lichens have a unique ability to grow in heavily contaminated areas due to the development of adaptative mechanisms allowing a high tolerance to metals as mentioned in this paper, and the chemical forms of these organisms are reported in the literature.
Abstract: Some lichens have a unique ability to grow in heavily contaminated areas due to the development of adaptative mechanisms allowing a high tolerance to metals. Here we report on the chemical forms of...
176 citations
TL;DR: In this paper, an introduction to equivariant cohomology, a classical tool for topological transformation groups, and intersection theory, a much more recent topic initiated by D. Edidin and W. Graham, is presented.
Abstract: This text is an introduction to equivariant cohomology, a classical tool for topological transformation groups, and to equivariant intersection theory, a much more recent topic initiated by D. Edidin and W. Graham.
163 citations
TL;DR: The hypothesis that the yellow phenotype might result from a deletion of the CCS gene is supported and these specific markers were integrated into the genetic map and will be useful for marker assisted plant breeding.
Abstract: The red colour of pepper fruits is determined by the y+ dominant allele and the yellow colour by the y recessive allele. The capsanthin-capsorubin synthase (CCS) gene is activated specifically during the final stages of pepper fruit ripening. RFLP and specific-PCR polymorphisms derived from the CCS gene were analysed in a F2 progeny of a red by yellow-fruited cross. They cosegregated completely with fruit colour. Our results support the hypothesis that the yellow phenotype might result from a deletion of the CCS gene. These specific markers were integrated into the genetic map and will be useful for marker assisted plant breeding.
137 citations
TL;DR: Adenovirus-mediated catalase gene transfer is validated as a realistic approach to reduce non specific inflammation effects on human or porcine islet grafts.
Abstract: Susceptibility of pancreatic islets to oxidant stress may affect islet viability and contribute to primary non function of allo- or xenogenic grafts. We investigated the influence of overexpression of catalase (CAT) on the viability of human, porcine and rat islets, as well as INS-1 beta-cell line. Islets were transfected with a replication-deficient adenovirus vector containing human CAT cDNA under the control of the adenovirus major late promoter (AdCAT) or a vector containing no foreign gene (AdNull) and used as a control. Oxidant stress was induced 48 h later by xanthine oxidase-hypoxanthine (XO 25 mU/ml, HX 0.5 mmol/l) or hydrogen peroxide (100 or 250 micromol/l). Islet cell viability was assessed 72 h after CAT transfer by 4-[3-(4-Idophenyl)-2-(4 nitrophenyl)-2H-5-tetrazolio]-1,2,benzene disulphonate (WST-1) test. Baseline catalase activity was three to fourfold lower in porcine than in human islets. CAT activity was reproducibly increased 2.5- to 7-fold in AdCAT infected islets, at least for 13 days. Overall, AdCAT conferred on human and pig islets a protection of 26.1 +/- 6.1 and 21.2 +/- 9.8% on XOHX injury and 35.4 +/- 4.2 and 57.9 +/- 10.5% on H2O2 stress. Similarly, rat islet cells and INS-1 cells were protected on XOHX stress by 17.8 +/- 2.3 and 30.8 +/- 8.7%, respectively. AdNull had no effect. Basal and stimulated insulin secretion was preserved in AdCAT-transfected human islets despite a XOHX challenge. This study validates adenovirus-mediated catalase gene transfer as a realistic approach to reduce non specific inflammation effects on human or porcine islet grafts. Moreover the relevance of defense mechanisms, previously suggested in human islets, is here illustrated in porcine islets.
125 citations
TL;DR: To determine the characteristic spectral signatures for all different combinations of fluorochromes, a novel multichannel image analysis method is developed, which is solely guided by the image information itself and does not require any user interaction.
Abstract: Multiplex-FISH (M-FISH) is a recently developed technique by which each of the two dozen human chromosomes-the 22 autosomes and the X and Y sex chromosomes-can be stained or "painted" with uniquely distinctive colors. Using a combinatorial labeling technique and a specially designed filter set, each DNA probe can be identified by its unique spectral signature. Here we present several significant optimizations of the M-FISH technology. First, a new strategy for labeling the probes is described which allows for easy and fast production of the complex M-FISH probe mix. Second, a newly developed, completely motorized microscope equipped with an eight-position filter wheel and a new generation of filter sets is presented that allows fully automatic imaging of a complete metaphase spread within seconds. Third, to determine the characteristic spectral signatures for all different combinations of fluorochromes, we developed a novel multichannel image analysis method. The spectral analysis is solely guided by the image information itself and does not require any user interaction. A complete analysis of a metaphase spread can be accomplished in less than 3 min. Sophisticated built-in quality controls were developed, and the value of visual inspection of M-FISH images as a simple means of controlling the computer-generated chromosome classification are illustrated. In addition, we discuss advantages of adding new fluorochromes to the traditionally used five fluorochromes.
115 citations
TL;DR: In this article, age data from the Virunga, Bukavu and Mwenga-Kamituga Volcanic Provinces in the Western Branch of the East African Rift System are given.
109 citations
TL;DR: In this paper, the authors present new astrometric observations made with Hipparcos, as well as photometry from the Hubble Space Telescope WFPC2 images, and combine these observations and reanalyzing previous work to estimate the age and masses of the stars in the system.
Abstract: HD 98800 is a system of four stars, and it has a large infrared excess that is thought to be due to a dust disk within the system. In this paper we present new astrometric observations made with Hipparcos, as well as photometry from Hubble Space Telescope WFPC2 images. Combining these observations and reanalyzing previous work allow us to estimate the age and masses of the stars in the system. Uncertainty in these ages and masses results from uncertainty in the temperatures of the stars and any reddening they may have. We find that HD 98800 is most probably about 10 Myr old, although it may be as young as 5 Myr or as old as 20 Myr old. The stars in HD 98800 appear to have metallicities that are about solar. An age of 10 Myr means that HD 98800 is a member of the post T Tauri class of objects, and we argue that the stars in HD 98800 can help us understand why post T Tauris have been so elusive, HD 98800 may have formed in the Centaurus star-forming region, but it is extraordinary in being so young and yet so far from where it was born.
01 Aug 1998
TL;DR: First order logic and standard information retrieval techniques are combined together, to the same effect: obtaining an expressive system, able to accurately handle complex documents, improve retrieval effectiveness, and achieve good time performance.
Abstract: This paper constitutes a proposal for an efficient and effective logical information retrieval system. Following a relational indexing approach, which is in our opinion a necessity to cope with the emerging applications such as those based on multimedia, we use the conceptual graphs formalism as our indexing language. This choice allows for relational indexing support and captures all the useful properties of the logical information retrieval model, in a workable system. First order logic and standard information retrieval techniques are combined together, to the same effect: obtaining an expressive system, able to accurately handle complex documents, improve retrieval effectiveness, and achieve good time performance. Experimentations on an image test collection, within a system available on the Web, provide an illustration of the role that logic may have in the future development of information retrieval systems.
TL;DR: Toxicity and consumption assays have not shown any toxicity of anthracene towards fungi, and zygomycetes appeared to be the most efficient group while Melanconiales were the least efficient.
TL;DR: Infusion of anti‐LFA1 plus anti‐CD2 monoclonal antibodies (MAb), combined with ex‐vivo T‐cell depletion of the graft, was efficient in preventing graft rejection and aGVHD.
Abstract: HLA-mismatched bone marrow transplantation (BMT) is hampered by three major complications: graft rejection, acute graft-versus-host disease (aGVHD) and delayed immune reconstitution. Infusion of anti-LFA1 plus anti-CD2 monoclonal antibodies (MAb), combined with ex-vivo T-cell depletion of the graft, was efficient in preventing graft rejection and aGVHD. Nevertheless, disease-free survival was limited by the high frequency of lethal infections, including EBV-induced lymphoproliferative disease (BLPD), which originates mostly from donor B cells, with an incidence of 5-30%. To decrease the rate of this complication, ex-vivo B-cell depletion was attempted. This study compares a group of 19 patients who received a T- and B-cell-depleted marrow from an HLA-mismatched related donor with a retrospective control group of 19 patients, who had received T-cell-depleted marrow by the same method. The level of T-cell depletion was similar in the two groups. For B-cell depletion, two different methods were compared. The median number of B cells infused in the study group was 0.46/kg. Engraftment and aGVHD incidence were similar in the two groups. No EBV donor-derived BPLD occurred in the study group, compared with seven in the control group, four of whom died because of EBV-BPLD. Event-free survival was significantly different between the two groups. We conclude that ex-vivo B-cell depletion of the graft may be a useful means of preventing EBV-BPLD, and warrants further study on a larger group of patients.
01 Aug 1998
TL;DR: An algorithm to compute rational function solutions for a first order system of linear difference equations with rational coefficients that does not require preliminary uncoupling of the given system is proposed.
Abstract: We propose an algorithm to compute rational function solutions for a first order system of linear difference equations with rational coefficients. This algorithm does not require preliminary uncoupling of the given system.
TL;DR: In this article, a full decomposition of transport is made and tabulated in terms of seasons, dynamic components (mean meridional, stationary eddy, transient eddy), and type of energy (sensible, latent, geopotential).
Abstract: Diagnostics of energy and moisture transport and disposal over the Antarctic polar cap (70°S to the pole) and ice sheet are extracted from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis archive over the 1979–93 period. Transport across 70°S is obtained from the 6-hourly analyses of wind, temperature, moisture, and geopotential, whereas top-of-the-atmosphere energy balance and surface energy and water fluxes are evaluated from 6- and 12-h forecasts. A full decomposition of transport is made and tabulated in terms of seasons, dynamic components (mean meridional, stationary eddy, transient eddy), and type of energy (sensible, latent, geopotential). For instance, in terms of type of energy, about 50% of the total converged to the polar cap is geopotential, which is almost entirely advected by the mean meridional circulation. Even though atmospheric moisture is very low, latent heat transport accounts for almost 20% of the total energy import, mostly by the transient eddies....
TL;DR: In patients with bilateral GPi stimulation for stage 4 Parkinson's disease with severe levodopa‐induced dyskinesias, the main interest of stimulation is the possibility of finding a compromise between LID alleviation in on‐phase without loss of the beneficial motor effects and improvement in parkinsonism in off‐phase.
Abstract: We report three patients with bilateral GPi stimulation for stage 4 Parkinson's disease (PD) with severe levodopa-induced dyskinesias (LID). In all three it was possible to completely inhibit LID using high-stimulation parameters. Parallel to complete inhibition of LID, an inhibition of the anti-akinetic effect of levodopa was observed, whereas, at the same time, rigidity was markedly improved. GPi stimulation is adaptable over time, and stimulation parameters have to be programmed according to off- and on-period motor symptoms. The main interest of stimulation is the possibility of finding a compromise between LID alleviation in on-phase without loss of the beneficial motor effects and improvement in parkinsonism in off-phase. In some patients, residual dyskinesias have to be accepted so as not to aggravate on-period motor symptoms by a presumed overinhibition of basal ganglia outflow.
TL;DR: In this paper, the authors construct approximate solutions to the time-dependent Schrodinger equation with error norms bounded by a constant factor of the norm of the errors, and prove that for sufficiently small values of the error norms, these solutions agree with exact solutions up to errors whose norms are bounded by C' \exp{-\gamma'/\hbar^{\sigma}} for some ε > 0.
Abstract: We construct approximate solutions to the time--dependent Schrodinger equation $i \hbar (\partial \psi)/(\partial t) = - (\hbar^2)/2 \Delta \psi + V \psi$ for small values of $\hbar$. If $V$ satisfies appropriate analyticity and growth hypotheses and $|t|\le T$, these solutions agree with exact solutions up to errors whose norms are bounded by $C \exp{-\gamma/\hbar}$, for some $C$ and $\gamma>0$. Under more restrictive hypotheses, we prove that for sufficiently small $T', |t|\le T' |\log(\hbar)|$ implies the norms of the errors are bounded by $C' \exp{-\gamma'/\hbar^{\sigma}}$, for some $C', \gamma'>0$, and $\sigma>0$.
20 Jul 1998
TL;DR: This paper tries to answer the question: are the involved concepts and techniques close enough to envision a common tool capable of supporting both domains?
Abstract: Software Configuration Management (SCM) is the discipline of controlling the evolution of a software product. Product Data Management (PDM) is the disciple of designing and controlling the evolution of a product design. For a long time, these two domains have been disconnected, but they probably share common concepts and techniques. Furthermore, any large product development includes a substantial (and growing) part of software development. There is a need to control the evolution of both the product and its associated software. Thus we are faced with the question: are the involved concepts and techniques close enough to envision a common tool capable of supporting both domains. This paper tries to answer this question, through an analysis of the PDM standard STEP and tools characteristic of both domains: Metaphase for PDM; Clear Case and Adele for SCM.
TL;DR: In this article, an excess of 66±14 (stat.) events were observed in the D∗+π+π−π− final state with a mass of 2637±2(stat.)±6(syst.) MeV/c2 and a full width smaller than 15 MeV /c2 (95% C.L.).
TL;DR: The 2-fold increase of nephropathy in E2 non-carriers with NIDDM argues for a role for LDL in the development of human nephtropathy in NID DM patients, and support evidence for the pathogenic and morphologic similarities between kidney disease and atherosclerosis in N IDDM patients.
Abstract: BACKGROUND Chronic hyperglycaemia stands with diabetes duration as the main predicting factor for the development of nephropathy in insulin dependent diabetes mellitus (IDDM). In contrast, nephropathy in non-insulin-dependent diabetes mellitus (NIDDM) presents with a different natural history and, as well as atherosclerosis, can precede diabetes diagnosis and even the onset of patent hyperglycaemia. The role of lipid abnormalities in this matter remains debated. METHODS We studied the prevalence of nephropathy (N+ = urinary albumin excretion rate (UAE) > 20 mg/d) in 134 Caucasian NIDDM patients ranked according to alipoprotein E (apoE) genotype (same distribution in 132 controls). Age, diabetes duration and sex ratio did not differ between N+ and N-. A patient with E2E4 (n = 1) was excluded from the analysis. RESULTS The prevalence of nephropathy was significantly reduced in E2 allele carriers (36%, 8/22) vs 69% (77/111) in E2 non-carriers (P < 0.01). Relative risk (RR) of E2 carriers developing nephropathy was 0.52 (95% CI = 0.35-0.80). Both groups were comparable in terms of age (55 +/- 11 vs 57 +/- 11 years), diabetes duration (15 +/- 9 vs 14 +/- 10 years) and prevalence of retinopathy (59 vs 48%). Similar results were observed when patients with diabetes duration longer than 8 years were studied (n = 94). CONCLUSIONS It has been largely established that low-density lipoprotein (LDL)-cholesterol level in E2 allele carriers (whether diabetic or not) was lower than in E2 non-carriers. The 2-fold increase of nephropathy in E2 non-carriers with NIDDM argues for a role for LDL in the development of human nephropathy in NIDDM patients. This result is in agreement with previous data established both in vitro and in vivo in animal models. These findings support evidence for the pathogenic and morphologic similarities between kidney disease and atherosclerosis in NIDDM patients.
TL;DR: In this paper, an update of the searches for charginos and neutralinos in DELPHI is presented, based mainly on recent data collected at centre-of-mass energies of 161 GeV and 172 GeV.
Abstract: An update of the searches for charginos and neutralinos in DELPHI is presented, based mainly on recent data collected at centre-of-mass energies of 161 GeV and 172 GeV. No signal is found. For a sneutrino with mass above 300 GeV/c2 and a mass difference between the chargino and the lightest neutralino above 10 GeV/c2, the lower limit at 95% confidence level on the chargino mass ranges from 84.3 GeV/c2 to the kinematical limit (86.0 GeV/c2), depending on the mixing parameters. The limit decreases for lower chargino-neutralino mass differences. The limit in the case of a light sneutrino is 67.6 GeV/c2, provided that that there is no light sneutrino with a mass within 10 GeV/c2 below the chargino mass. Upper limits on neutralino pair production cross-sections of about a picobarn are derived. The (μ,M2) domain excluded in the MSSM-GUT scenario is determined by combining the neutralino and chargino searches. These results imply a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 24.9 GeV/c2 for tans >- 1. The search has also been extended to the case where the lightest neutralino is unstable and decays into a photon and a gravitino. imply a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 24.9 GeV/c2 for tans >- 1. The search has also been extended to the case where the lightest neutralino is unstable and decays into a photon and a gravitino.
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TL;DR: The value of the b quark mass at the M Z scale defined in the MS renormalization scheme was determined using 2.8 million hadronic Z decays collected during 1992-1994 by the DELPHI detector to be m b (M Z )=2.67±0.25 ( stat. )± 0.34 ( frag. )−0.27 ( theo. ) GeV/c 2 ).
TL;DR: The optical spectropluviometer is a shadowgraph instrument able to measure independently the equivalent diameter and the fall speed of raindrops at ground level as discussed by the authors, and it has been used to estimate the rain rate from the measured drop size distributions with rain rates delivered by nearby rain gauges.
Abstract: The optical spectropluviometer is a shadowgraph instrument able to measure independently the equivalent diameter and the fall speed of raindrops at ground level. Hardware and software modifications are proposed and tested. A modern digital signal processing system allows for the simultaneous sampling and analyzing of the signal delivered by the sensor. The IR light transmission is pulsed to avoid interference with natural radiation and the protection of the optics is improved. The validation procedure consists of comparing the rain rates derived from the measured drop size distributions with rain rates delivered by nearby rain gauges. The results obtained during 65 storm events show that the proposed improvements reduce the bias of the rain-rate estimation from 34% to 16%. Suggestions are given to further improve the performance of this instrument.
TL;DR: The OPTIMISM seismic experiment on Mars as discussed by the authors was designed to perform a seismic reconnaissance of Mars, to constrain the level of martian seismic noise and its level of seismicity.
TL;DR: A search for stable and long-lived heavy charged particles used the data taken by the DELPHI experiment at energies from 130 to 183 GeV as mentioned in this paper, where the Cherenkov light detected in the Ring ImagingCherenkov D...
TL;DR: In this article, donnons des obstructions de nature locale a la possibilite de relever en caracteristique zero un revetement galoisien de courbes algebriques lisses defini sur un corps close de carcharacteristique p > 0.
Abstract: Resume Nous donnons des obstructions de nature locale a la possibilite de relever en caracteristique zero un revetement galoisien de courbes algebriques lisses defini sur un corps algebriquement clos de caracteristique p > 0.
TL;DR: In this paper, the total and the differential cross sections for the reaction e+e− → γγ(γ) have been measured with the DELPHI detector at LEP using an integrated luminosity of 36.9 pb−1.