Development of a rapid risk evaluation tool for herbs/drugs interactions in cancer patients: a multicentric experience in south of France.

Cancer patients use herbs in spite of severe interactions risks with major anticancer drugs. In daily practice, it is very difficult for oncologists to detect and define the risk of a herb-anticancer drug interaction (HDI). In this work, we realised a state of play in one of the most populated region of France by evaluating, through a specific questionnaire, the position of a representative panel of oncologists. About 80% of them thought that herbs interact with anticancer treatments whereas only 15.4% of them actually knew the real HDI. About 89.1% of them thought that a practical detection tool would be relevant and useful for their daily practice. Then, we constructed a tool in order to rapidly evaluate a HDI risk level. Based on experts' reviews and using a criticality matrix, we determined the HDI risk level between 11 herbs and 126 anticancer drugs. Then, we measured satisfactory of oncologists. All of them considered the tool as useful in their daily practice and then used it. This work highlighted that even if HDI has been integrated as a theoretical risk, its practical detection and risk evaluation is difficult to implement for oncologists in their daily practice. Thus, the tool we developed should answer to an unmet medical need.

What can be learned from a chaotic cancer model?

A simple model of three competing cell populations (host, immune and tumor cells) is revisited by using a topological analysis and computing observability coefficients. Our aim is to show that a non-conventional analysis might suggest new trends in understanding the interactions of some tumor cells and their environment. The action of some parameter values on the resulting dynamics is investigated. Our results are related to some clinical features, suggesting that this model thus captures relevant phenomena to cell interactions.

Nonstationarity signatures in the dynamics of global nonlinear models.

The aim of this paper is to learn how to recognize a posteriori signatures that nonstationarity leaves on global models obtained from data. To this end the effects of nonstationarity on the dynamics of such models are reported for two benchmarks. Parameters of the Rössler and Lorenz models are varied to produce nonstationary data. It is shown that not only the rate of change of the varying parameter but also which recorded variable is used to estimate global models may have visible effects on the results, which are system-dependent and therefore difficult to generalize. Although the effects of nonstationarity are not necessarily obvious from the phase portraits, the first-return map to a Poincaré section is a much more adequate tool to recognize such effects. Three examples of models previously obtained from experimental data are analyzed in the light of the concepts discussed in this paper.

Finger tapping movements of Parkinson's disease patients automatically rated using nonlinear delay differential equations.

Parkinson's disease is a degenerative condition whose severity is assessed by clinical observations of motor behaviors. These are performed by a neurological specialist through subjective ratings of a variety of movements including 10-s bouts of repetitive finger-tapping movements. We present here an algorithmic rating of these movements which may be beneficial for uniformly assessing the progression of the disease. Finger-tapping movements were digitally recorded from Parkinson's patients and controls, obtaining one time series for every 10 s bout. A nonlinear delay differential equation, whose structure was selected using a genetic algorithm, was fitted to each time series and its coefficients were used as a six-dimensional numerical descriptor. The algorithm was applied to time-series from two different groups of Parkinson's patients and controls. The algorithmic scores compared favorably with the unified Parkinson's disease rating scale scores, at least when the latter adequately matched with ratings from the Hoehn and Yahr scale. Moreover, when the two sets of mean scores for all patients are compared, there is a strong (r = 0.785) and significant (p<0.0015) correlation between them.

First identification of ITM2B interactome in the human retina.

Integral Membrane Protein 2 B (ITM2B) is a type II ubiquitous transmembrane protein which role remains unclear. ITM2B mutations have been associated with different disorders: mutations leading to longer mutant proteins have been reported in two distinct Alzheimer-like autosomal dominant disorders with early-onset progressive dementia and cerebellar ataxia. Both disorders share neurological features including severe cerebral amyloid angiopathy, non-neuritic plaques, and fibrillary tangles as in Alzheimer disease. Our group reported a missense mutation in ITM2B, in an unusual retinal dystrophy with no dementia. This finding suggests a specific role of ITM2B in the retina. As the identification of retinal-specific ITM2B partners could bring new insights into the cellular functions of ITM2B, we performed quantitative proteomics of ITM2B interactome of the human retina. Overall, 457 ITM2B partners were identified with 8 of them involved in visual transduction. In addition, bulk Gene Ontology analyses showed that many ITM2B partners are involved in several other biological functions, such as microtubule organization, protein translation and interestingly, mitochondrial homeostasis. These data represent the first report of the ITM2B interactome in the human retina and may serve as a valuable inventory of new potential ITM2B partners for future investigations of ITM2B physiological functions and dysfunctions.

Protecting effect of vitamin E supplementation on submaximal exercise-induced oxidative stress in sedentary dogs as assessed by erythrocyte membrane fluidity and paraoxonase-1 activity.

The aim of this placebo-controlled study was to investigate the effects of oral vitamin E supplementation for 10 weeks on exercise-induced oxidative damage in untrained dogs. Eight dogs were randomly assigned to a supplementation (n=4) or control (n=4) group and underwent two isolated submaximal exercise sessions, 10 weeks apart. Blood was collected during each session to measure erythrocyte membrane fluidity (EMF), paraoxonase-1 (PON1) activity, plasma malondialdehyde (MDA) and vitamin E concentrations. These biomarkers were measured in venous blood samples collected before (t(0)), just after (t, EMF only) and 1d (t+1d) and 7d (t+7d) after the dogs ran on a treadmill. Prior to vitamin E supplementation, exercise induced a significant decrease in PON1 activity, EMF, vitamin E concentration and a significant increase in MDA concentration at t+1d. After a 10 week vitamin E supplementation period, these exercise-induced changes in PON1 activity, EMF and MDA concentration were still significant in the control group, but not in the supplemented group. These results suggested that vitamin E supplementation had a protective effect on submaximal exercise-induced oxidative damage in sedentary dogs.

Comparison of tests for embeddings.

It is possible to compare results for the classical tests for embeddings of chaotic data with the results of a recently proposed test. The classical tests, which depend on real numbers (fractal dimensions, Lyapunov exponents) averaged over an attractor, are compared with a topological test that depends on integers. The comparison can only be done for mappings into three dimensions. We find that the classical tests fail to predict when a mapping is an embedding and when it is not. We point out the reasons for this failure, which are not restricted to three dimensions.

When are projections also embeddings?

We study an autonomous four-dimensional dynamical system used to model certain geophysical processes. This system generates a chaotic attractor that is strongly contracting, with four Lyapunov exponents lambdai that satisfy lambda1+lambda2+lambda3<0 , so the Lyapunov dimension is DL=2+|lambda3|/lambda1<3 in the range of coupling parameter values studied. As a result, it should be possible to find three-dimensional spaces in which the attractors can be embedded so that topological analyses can be carried out to determine which stretching and squeezing mechanisms generate chaotic behavior. We study mappings into R3 to determine which can be used as embeddings to reconstruct the dynamics. We find dramatically different behavior in the two simplest mappings: projections from R4 to R3 . In one case the one-parameter family of attractors studied remains topologically unchanged for all coupling parameter values. In the other case, during an intermediate range of parameter values the projection undergoes self-intersections, while the embedded attractors at the two ends of this range are topologically mirror images of each other.

Effects of exercise and oral antioxidant supplementation enriched in (n-3) fatty acids on blood oxidant markers and erythrocyte membrane fluidity in horses.

The aim of this study was to investigate in a placebo-controlled field study the effect of a (n-3)-vitamin supplementation on erythrocyte membrane fluidity (EMF), oxidant/antioxidant markers and plasmatic omega3/omega6 fatty acid ratio (FAR) in 12 eventing horses. Venous blood was sampled at rest before (PRE) and after (POST) a three week treatment period with either the supplement (group S, n=6) or a placebo (group P, n=6) as well as after 15min (POST E15') and 24h (POST E24h) after a standardised exercise test. The following markers were analysed: EMF, plasma antioxidant capacity of water and lipid soluble components, ascorbic acid, uric acid (UA), glutathione (reduced: GSH, oxidised: GSSG), vitamin E (Vit E), beta-carotene, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity, selenium, copper (Cu), zinc (Zn), oxidised proteins (Protox), lipid peroxides (Pool) and FAR. EMF did not differ between group S and P after treatment, but GPx remained unchanged in group S whereas it decreased in group P and plasma Cu/Zn ratio remained unchanged whereas it increased in group P. FAR were significantly increased in group S. Exercise induced a significant decrease of EMF (POST vs. E24h) in both groups, but which was significantly lower at E15' in group S than in group P. Exercise induced a significant increase of UA and ACW (POST vs. E15') and Protox (POST vs. E24h) in both groups. An exercise-related decrease in GSH and Pool (POST vs. E15') was found in group P, whereas Vit E and FAR (POST vs. E24h) significantly decreased in both groups. The study showed that exercise induced a decrease in EMF in horses associated with changes of blood oxidative balance. The (omega-3)-vitamin supplementation tested improved the oxidative balance poorly but delayed the exercise-induced decrease of EMF and increased the FAR.

Real Time RT-PCR for the detection and quantitation of bovine respiratory syncytial virus.

A quantitative Real Time RT-PCR assay was developed to detect and quantify bovine respiratory syncytial virus (BRSV) in the respiratory tract of infected animals. A pair of primers and a TaqMan probe targeting conserved regions of the nucleoprotein gene of BRSV were designed. The detection limit of the assay was shown to be 10(3) RNA copies and standard curve demonstrated a linear range from 10(3) to 10(8) copies as well as an excellent reproducibility. The efficiency of the BRSV Real Time RT-PCR was then assessed by detecting BRSV in lungs, tracheas and bronchoalveaolar fluids (BAL) samples of experimentally infected calves. The assay was shown to be 100 times more sensitive than conventional RT-PCR and was more efficient for BRSV diagnosis. Finally, the Real Time RT-PCR was used to quantify BRSV load in BAL fluids of four experimentally infected calves for 14 days. The high sensitivity, rapidity and reproducibility of the BRSV Real Time RT-PCR make this method suitable for diagnostic and for the evaluation of the efficiency of new vaccines.

Detection of BVDV persistently infected animals in Belgium: evaluation of the strategy implemented.

Until now, no official bovine virus diarrhea virus (BVDV) control program has been implemented in Belgium. The only legislation dealing with the detection of BVDV-infected animals concerns the purchase of animals. A strategy of control, based on the identification and elimination of persistently infected (PI) animals and the vaccination of cows before insemination has been designed in both the Northern and the Southern part of the country. The strategy of detection of PI animals relies on PCR testing of pools of blood. Individual blood samples corresponding to the positive pools are then tested by BVDV-antigen ELISA. A first evaluation of the measures already applied in Belgium is presented. Data obtained in 2003 are presented and discussed regarding the validation of the laboratory strategy, the prevalence of positive herds, the genotype of circulating viruses, the outcome of antigen positive animals and the need for improvement of the current legislation.

Genetic and antigenic variability in bovine viral diarrhea virus (BVDV) isolates from Belgium.

This report describes the genetic and antigenic variability of bovine viral diarrhea virus strains isolated in Belgium. Part of the 5' untranslated region and the 5' end of the gp53 (E2) coding sequence were amplified by PCR and sequenced. Phylogenetic analysis showed that most field isolates segregated into genotypes Ib or II. Only one out of 28 field isolates belonged to genotype Ia. Interestingly, some type I strains were equally divergent from types Ia and Ib strains and clustered into additional subtypes within genotype I. Immune sera from young calves experimentally inoculated with field isolates first identified on the basis of their sequences were used in two-way neutralisation experiments. The results clearly differentiated type I from type II strains although some degree of cross-neutralisation was observed. Within type I, the new clusters could not be antigenically differentiated from the more prevalent type Ib strains or from type Ia strain NADL, suggesting that BVDV genotype I is antigenically homogeneous. The isolation of BVDV types I and II strains from cell lines and from a bovine vaccine suggest that molecular epidemiology surveillance is warranted for BVDV.

Real-time PCR for simultaneous detection and genotyping of bovine viral diarrhea virus.

Since two genotypes of bovine viral diarrhea viruses (BVDV) occur in Belgian herds, their differentiation is important for disease surveillance. A quantitative real-time PCR assay was developed to detect and classify bovine viral diarrhea viruses in genotype I and II. A pair of primers specific for highly conserved regions of the 5'UTR and two TaqMan probes were designed. The FAM and VIC-labeled probe sequences differed by three nucleotides, allowing the differentiation between genotype I and II. The assay detectability of genotype I and II real-time PCR assay was 1000 and 100 copies, respectively. Highly reproducible data were obtained as the coefficients of variation of threshold cycle values in inter-runs were less than 2.2%. The correct classification of genotype I and II viruses was assessed by using reference strains and characterized field isolates of both genotypes. The application to clinical diagnosis was evaluated on pooled blood samples by post run measurement of the FAM- and VIC-associated fluorescence. The 100% agreement with the conventional RT-PCR method confirmed that this new technique could be used for routine detection of persistently infected immunotolerant animals.

Determination of lipoprotein(a) concentrations and apolipoprotein(a) molecular weights in diabetic patients.

Lipoprotein(a) (Lp(a)) with atherogenic and thrombotic properties has been frequently studied in diabetes, because a high cardiovascular risk has been reported both in type 1 and type 2 diabetes. Few studies have considered genetic factors, especially the isoforms of apolipoprotein(a). The aim of this work is to determine the distribution of apo(a) phenotypes in the serum of 148 diabetic patients (59 type 1, 89 type 2) with or without vascular complications. Apo(a) phenotypes are determined using 4-15% sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by immunoblotting (PhastSystem - Pharmacia). An inverse relationship is observed between Lp(a) serum concentration and the apparent molecular mass of apo(a) isoforms: type 1 r=- 0.61, p<0.01; type 2 r=- 0.55, p<0.01. The frequency of apo(a) isoforms is significantly different between type 1 and type 2 diabetes mellitus. A higher prevalence of isoforms of low molecular weight was observed in the type 2 diabetic population.

Serum paraoxonase activity and paraoxonase gene polymorphism in type 2 diabetic patients with or without vascular complications.

BACKGROUND: Serum paraoxonase (PON) activity and the relevance of PON gene polymorphism in vascular complications of type 2 diabetic patients were investigated in a case-control study. METHODS: The population included 105 control subjects, 96 diabetic patients without vascular complications and 71 diabetics with vascular complications. RESULTS: Serum PON activity was significantly decreased (p<0.001) in diabetic patients without vascular complications: 207 IU (25-817) compared with the controls: 259 IU (24-950). Although serum PON activity was also decreased: 232 IU (34-797) in the population with vascular complications, the difference was not statistically significant (p=0.11). The Q192 allele frequency is significantly higher (p<0.005) in diabetics without vascular complications (77%), and with vascular complications (73%) than in the controls (63%). No significant association was found between either PON(1)55 L/M and PON(2)311 C/S gene polymorphisms and vascular complications. CONCLUSIONS: The difference in allele frequency for the PON(1) Q/R 192 gene polymorphism may be the cause of the low paraoxonase activity observed in type 2 diabetes mellitus. Further studies need to be conducted to elucidate the role of the enzyme in the development of vascular complications in diabetes.

Detection and genotyping of bovine diarrhea virus by reverse transcription-polymerase chain amplification of the 5' untranslated region.

A reverse-transcription polymerase chain reaction (RT-PCR) was developed to differentiate the bovine diarrhea virus (BVDV) from other pestiviruses, and to determine the genotype of the BVDV isolates. For this purpose, primer pairs were selected in the 5' untranslated region (5'UTR). The primers BE and B2 were located in highly conserved regions and were pestivirus-specific. Two primer pairs named B3B4 and B5B6 were specific of BVDV genotypes I and II, respectively. With this technique, an amplification product of the expected size was obtained with either the B3B4 or the B5B6 primer pairs for the 107 BVDV isolates tested but not for BDV or CSFV. For some isolates that were grouped in the genotype II, sequence analysis of the PCR fragments confirmed their classification into this genotype.

Characterization of monoclonal antibodies directed against the bovine herpesvirus-1 glycoprotein E and use for the differentiation between vaccinated and infected animals.

A panel of seven monoclonal antibodies (MAbs) directed against the bovine herpesvirus-1 (BHV-1) glycoprotein E (gE) was obtained. For that purpose, mice were either tolerized to BHV-1 gE-negative virus and then immunized with wild type BHV-1 or immunized with plasmid DNA expressing the gE and gI glycoproteins. The MAbs were characterized by their reactivity with the gE protein or the gE/gI complex and by competition experiments. Results showed that the MAbs were directed against three antigenic domains, two located on the gE glycoprotein and one on the gE/gI complex. Blocking experiments were performed with sera from experimentally vaccinated and infected cattle. A competition was observed between gE-positive bovine sera and six of the seven MAbs. The bovine sera thus recognized two of the three antigenic sites. Field sera were then tested in blocking enzyme-linked immunosorbent assay using one horseradish peroxidase-conjugated MAb. A specificity of 98.2% and a sensitivity of 98.2% compared to the commercially available test were observed.

Expression of the bovine leukemia virus transactivator protein p34 by a recombinant vaccinia virus.

In order to characterize the bovine leukemia virus transactivator protein, a recombinant vaccinia virus (v-LOR) containing the BLV post-envelope long open reading frame was constructed. v-LOR was shown to encode a functional protein able to transactivate the BLV long terminal repeat-directed gene expression in the infected cells. The encountered level of transactivation was about one third of that measured in BLV-infected fetal lamb kidney cell lysates.

Covering dynamical systems: twofold covers.

We study the relation between a dynamical system, which is unchanged (equivariant) under a discrete symmetry group G and another locally identical dynamical system with no residual symmetry. We also study the converse mapping: lifting a dynamical system without symmetry to a multiple cover, which is equivariant under G. This is done in R3 for the two element rotation and inversion groups. Comparisons are done for the equations of motion, the strange attractors that they generate, and the branched manifolds that classify these strange attractors. A dynamical system can have many inequivalent multiple covers, all equivariant under the same symmetry group G. These are distinguished by the value of a certain topological index. Many examples are presented. A new global bifurcation, the "peeling bifurcation," is described.

Unimodal order in the image of the simplest equivariant chaotic system.

The simplest equivariant chaotic dynamics is investigated in terms of its image, i.e., under the 2-->1 mapping allowing one to obtain a projection of the dynamics without any residual symmetry. The inversion symmetry is therefore deleted. The bifurcation diagram can thus be predicted from the unimodal order although the first-return map computed in the original phase space exhibits three critical points. This feature is the same as the one observed on the Burke and Shaw system although this latter system has a rotation symmetry.