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Biomedical subjects

P Gallois

Publications and source records attributed to P Gallois.

At least 19 recordsLinked to original sources
PubMed2001

Paternally inherited transgenes are down-regulated but retain low activity during early embryogenesis in Arabidopsis.

We investigated the timing of transgene activation after fertilisation in Arabidopsis following crosses and using two transgenic promoters (from the AtCYCB1 and AtLTP1 genes). Using both a transactivation system and direct transcriptional fusion to drive beta-glucuronidase reporter expression, reciprocal crosses showed a lack of expression of the paternal components. This is consistent with a lack of paternal genome activity previously reported during early seed development in Arabidopsis [Viella-Calzada et al. (2000) Nature 404, 91-94]. However, transactivation experiments of the BARNASE gene gave evidence that at least some paternal loci retain transcriptional activity, though at a low level, during early embryogenesis.

Arabidopsis↗
PubMed2001

A double blind randomized controlled trial of Maharishi Vedic vibration technology in subjects with arthritis.

To explore ancient Vedic medical techniques, one hundred and seventy-six subjects with arthritis participated in a controlled study through the non-pharmacologic approach known as the Maharishi Vedic Vibration Technology (MVVT). Using a double-blinded and randomized experimental design, the findings showed significant reductions of pain and stiffness, and improvement in range of motion in the study sample. One hundred percent relief of symptoms was the most commonly reported category of improvement due to treatment. For the group as a whole, differences in mean response of treatment and control conditions with respect to relief of pain, limitation of motion, and reduction in stiffness were highly significant: t values ranged from a low of 5.609 in stiffness to a high of 20.950 in pain, p = 0.000009 to <10-49 respectively. Analysis by sub-categories of peripheral arthritis, painful conditions of the spine, and rheumatoid arthritis likewise produced significant results. Mechanisms of action were proposed, drawing on Maharishi Vedic Science, developments in quantum field theory, and specifically the theories of chaos and self-organizing systems as they relate to physiological functioning. The instantaneous relief of pain and improvement in function in such a high proportion of subjects with chronic arthritis is unparalleled in modern medical science

Arthralgia↗
PubMed2001

Silver stained isoelectrophoresis of tears and cerebrospinal fluid in multiple sclerosis.

Cerebrospinal fluid (CSF) analysis aids in the diagnosis of multiple sclerosis. However, this examination is invasive. The aim of this study was to assess the potentials of a new method of tears isoelectrophoresis (IEF). Silver staining of IEF was used to examined tears and CSF from 123 patients including 60 patients with multiple sclerosis (MS), 50 other neurological patients and 13 patients with inflammatory neurological diseases. Tears were collected on a Shirmer strip placed in one eye, avoiding reflex secretion. This method of IEF with silver staining allowed the detection of oligoclonal bands in tears that were truly immunoglobulin G on immunofixation. The concordance rate between tears and CSF was 83%, meaning that CSF provided no more information than tears analysis in 83% of cases. Sensitivity in tears (72%) and CSF (75%) was very close as was specificity (respectively 84 % and 86 %). High concordance between tears and CSF is the first step in developing a non invasive test which could replace lumbar puncture, particularly when this procedure is not fearalele or is refused by the patient.

Adolescent↗
PubMed2001

Future of early embryogenesis studies in Arabidopsis thaliana.

Embryogenesis is a long-standing field of interest for plant scientist as recorded in the 'notes' of the French Science Academy. This either with fundamental or applied points of view. Since the beginning of the century techniques and questions have co-evolved, from microscope and fate map to laser ablation and cell-cell signalling. So far in plant embryogenesis, a limited use has been made of the whole range of approaches generally available to study development. This is due to technical limitations when working with plant embryos. Novel mutant screens and techniques are now at hand and are expected to unravel further the nature of cell interactions underlying embryo development. This in turn will modify the focus of our questioning.

Arabidopsis↗
PubMed2001

Transactivation of BARNASE under the AtLTP1 promoter affects the basal pole of the embryo and shoot development of the adult plant in Arabidopsis.

Genetically controlled expression of a toxin provides a tool to remove a specific structure and consequently study its role during a developmental process. The availability of many tissue-specific promoters is a good argument for the development of such a strategy in plants. We have developed a conditional system for targeted toxin expression and demonstrated its use for generating embryo phenotypes that can bring valuable information about signalling during embryogenesis. The BARNASE gene was expressed in the Arabidopsis embryo under the control of two promoters, one from the cyclin AtCYCB1 gene and one from the AtLTP1 gene (Lipid Transfer Protein 1). One-hundred percent seed abortion was obtained with the cyclin promoter. Surprisingly however, the embryos displayed a range of lethal phenotypes instead of a single arrested stage as expected from this promoter. We also show that BARNASE expression under the control of the AtLTP1 promoter affects the basal pole of the globular embryo. Together with reporter expression studies, this result suggests a role of the epidermis in controlling the development of the lower tier of the embryo. This defect was not embryo-lethal and we show that the seedlings displayed a severe shoot phenotype correlated to epidermal defects. Therefore, the epidermis does not play an active role during organogenesis in seedlings but is important for the postgermination development of a viable plant.

Arabidopsis↗
PubMed2000

Accumulation and nuclear targeting of BnC24, a Brassica napus ribosomal protein corresponding to a mRNA accumulating in response to cold treatment.

Previously, we described two cDNA clones corresponding to a new family of cold regulated genes, pBnC24a and pBnC24b homologous to the human BBC1 (Breast Basic Conserved) gene. In order to further analyze the function and regulation of these two genes we have prepared antibodies against a recombinant fusion protein, MBP-BnC24A and used them to study expression at the protein level. In contrast to the increased mRNA accumulation induced by cold, immuno-blot analysis showed that the quantity of the BnC24 protein was not correlated with the accumulation of BnC24 transcripts and is identical in both control and low temperature treated (4 degrees C) plants, suggesting a translational or post-translational regulation. This was confirmed by overexpressing BnC24 in transgenic Arabidopsis thaliana plants. Despite a substantial increase in mRNA, the BnC24 protein level is unchanged. In addition, we demonstrated by subcellular fractionation and immunodetection that a significant fraction of BnC24 protein is located in the nucleus. Using a GUS fusion construction and biolistic experiments it was found that a portion of the amino terminal region is sufficient to target this protein to the nucleus. These results are consistent with the recent finding that BBC1 and its homologues code for the ribosomal large subunit protein L13. In addition they illustrate the difficulty of correlating accumulation of a given mRNA in response to a given stimulus with a biologically significant role in the adaptation to a new environment.

Journal Article↗
PubMed2000

The distribution of T-DNA in the genomes of transgenic Arabidopsis and rice.

Almost all the nuclear genes of four Gramineae (maize, wheat, barley, rice) and pea are located in DNA fractions covering only a 1-2% GC range and representing between 10 and 25% of the different genomes. These DNA fractions comprise large gene-rich regions (collectively called the 'gene space') separated by vast gene-empty, repeated sequences. In contrast, in Arabidopsis thaliana, genes are distributed in DNA fractions covering an 8% GC range and representing 85% of the genome. Here, we investigated the integration of a transferred DNA (T-DNA) in the genomes of Arabidopsis and rice and found different patterns of integration, which are correlated with the different gene distributions. While T-DNA integrates essentially everywhere in the Arabidopsis genome, integration was detected only in the gene space, namely in the gene-rich, transcriptionally active, regions of the rice genome. The implications of these results for the integration of foreign DNA are discussed.

Arabidopsis↗
PubMed1998

UV-C radiation induces apoptotic-like changes in Arabidopsis thaliana.

With a view to studying programmed cell death in plants at the molecular level, we report here for the first time that apoptotic-like changes are induced by UV radiation in plant nuclei. In Arabidopsis thaliana seedlings a UV-C dose of 10-50 kJ/m2 induces an oligonucleosomal DNA fragmentation which is reminiscent of the apoptotic DNA ladder described in animal cells. This DNA fragmentation was also detected in situ in protoplast nuclei as soon as 2 h after UV-C treatment. Moreover, UV-C induced a nuclear morphology characteristic of animal apoptotic nuclei. We propose that UV-C induction constitutes a powerful tool to compare the cellular response to irreversible UV damage in plants to that in animals and to study programmed cell death in A. thaliana.

Apoptosis↗
PubMed1998

Mutations in Arabidopsis thaliana genes involved in the tryptophan biosynthesis pathway affect root waving on tilted agar surfaces.

Arabidopsis thaliana roots grow in a wavy pattern upon a slanted surface. A novel mutation in the anthranilate synthase alpha 1 (ASA1) gene, named trp5-2wvc1, and mutations in the tryptophan synthase alpha and beta 1 genes (trp3-1 and trp2-1, respectively) confer a compressed root wave phenotype on tilted agar surfaces. When trp5-2wvc1 seedlings are grown on media supplemented with anthranilate metabolites, their roots wave like wild type. Genetic and pharmacological experiments argue that the compressed root wave phenotypes of trp5-2wvc1, trp2-1 and trp3-1 seedlings are not due to reduced IAA biosynthetic potential, but rather to a deficiency in L-tryptophan (L-Trp), or in a L-Trp derivative. Although the roots of 7-day-old seedlings possess higher concentrations of free L-Trp than the shoot as a whole, trp5-2wvc1 mutants show no detectable alteration in L-Trp levels in either tissue type, suggesting that a very localized shortage of L-Trp, or of a L-Trp-derived compound, is responsible for the observed phenotype.

Alleles↗
PubMed1998

[Traumatic bilateral paralysis of the abducens nerve without cervical fracture].

We report the case of a 75-year-old woman with an uneventful medical history who presented with sudden-onset diplopia immediately after neck trauma in a traffic accident. Clinical and ophthalmological examinations were consistent with bilateral abducens nerve palsy. The causal relationship, including the medicolegal implications and the pathophysiological mechanism are discussed. The case demonstrates that exceptionally benign trauma can cause severe diplopia. The delay to recovery may be very long, suggesting caution concerning the decision of surgical care.

Abducens Nerve Injury↗
PubMed1997

[Sensorimotor polyneuropathy in a flare-up of Crohn disease].

A 22-year-old man developed an axonal sensorimotor polyneuropathy and an episode of pyloroduodenal stenosis at the same time. Rectal biopsy established the diagnosis of Crohn's disease. The etiologic investigations were negative. The neurological and gastrointestinal troubles improved and followed a parallel course. Without vitamin deficiency or metronidazole treatment, peripheral polyneuropathy is a rare event in Crohn's disease. An autoimmune cause is suspected.

Adult↗
PubMed1997

[Diagnostic importance of middle latency auditory evoked potentials (MLAEP) in multiple sclerosis].

This study was aimed at assessing the interest of middle latency auditory evoked potentials (MLAEP) recordings in multiple sclerosis (MS). Brainstem auditory evoked potentials (BAEP) and MLAEP were recorded in 40 control subjects and 65 patients who had MS according to Poser's criteria. Na and Pa latencies were significantly delayed in the MS group. These abnormalities were detected in 60% of the patients. In 26% of the cases with normal BAEP, abnormalities of MLAEP were present. In 71% of the patients abnormalities of both BAEP and MLAEP were observed. These results suggest the ability of MLAEP recordings to detect lesions of the auditory pathways rostral to the pons and show the value of their combined recordings in MS patients.

Adult↗
PubMed1997

A new Arabidopsis nucleic-acid-binding protein gene is highly expressed in dividing cells during development.

An Arabidopsis thaliana cDNA encoding a new RNA-binding protein (RBP37) was cloned from a silique cDNA library. The predicted amino acid sequence corresponds to a RBP containing two RNA recognition motifs (RRM) and a basic domain. An affinity for nucleic acids was confirmed in binding assays using in vitro synthesised AtRBP37 protein. In situ hybridisation experiments on sections of flowers and siliques showed expression only in growing organs: gynoecium, petals, filaments and during early-embryogenesis expression is located in the embryo proper and the suspensor up to late heart stage. Expression is not detected in the embryo during maturation. This results suggests an expression pattern correlated with dividing cells.

Amino Acid Sequence↗
PubMed1997

An Arabidopsis thaliana cDNA complementing a hamster apoptosis suppressor mutant.

Programmed cell death or apoptosis is a process in which unwanted cells are eliminated during growth and development. In mammals, several genes have been identified whose products are necessary to prevent entry into the apoptotic process. We have isolated a clone from an Arabidopsis thaliana cDNA library whose predicted translation product shows highly significant similarity to the mammalian defender against apoptotic death 1 (DAD1) protein. Transformation of the mutant hamster tsBN7 cells, which undergo apoptosis at restrictive temperature, demonstrates that the plant protein is as efficient as human DAD1 in rescuing these hamster cells from apoptosis. In contrast to mammals, Southern hybridisation and genomic data indicate that there are probably two genes in Arabidopsis thaliana. Northern blot analysis shows that AtDAD transcripts are present in all tissues examined, although the abundance of the transcripts is reduced in siliques during the maturation and desiccation phase of the seed. This is the first experimental proof that a homologue of an animal gene involved in apoptosis exists in plants and the first demonstration of complementation of a vertebrate mutant by a plant cDNA. Our results suggest that this process of suppression of apoptosis has been conserved in animals and plants.

Amino Acid Sequence↗
PubMed1997

Variations of IL2, IL6, TNF alpha plasmatic levels in relapsing remitting multiple sclerosis.

We performed a longitudinal analysis of serum IL2, IL6 and TNF alpha concentrations in 40 relapsing remitting MS patients and 20 healthy subjects. Disease activity was quantified by Minimal Record of Disease (M.R.D.) for MS, every 2 or 3 months. IL2, IL6 TNF alpha production was analysed without and with PHA stimulation of whole blood for 2 hours at 37 degrees C. No significant change in IL2 level was found in MS serum. Individual TNF alpha production was significantly increased (P < 0.007) during relapses. The global spontaneous IL6 production was markedly higher in the relapse group than in the control group (P < 0.01) and than in the remission group (P < 0.002) without significant individual variations of cytokine levels regarding the disease activity. Productions of cytokines were enhanced by PHA stimulation, a condition that however suppressed the differences observed without mitogen stimulation. Our data suggest that TNF alpha could be a marker for relapses while IL6 might reflect the global activity of the immune system in MS.

Adult↗