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F Gaillard

Publications and source records attributed to F Gaillard.

At least 37 records · Page 2Linked to original sources
PubMed1998

Expression and function of tap in the gustatory and olfactory organs of Drosophila.

We have recently described the identification of a gene, tap, which encodes a bHLH protein expressed in one neuron of each larval chemosensory organ. Here we show that tap is expressed at a late stage in the development of one type of adult chemosensory organ, the gustatory bristles of the leg, wing and proboscis. We also show that tap is expressed very early in the development of a second type of chemosensory receptors, the olfactory organs of the antenna. The results of behavioral experiments suggest that the ectopic expression of tap affects the response to sugar and salt.

Animals↗
PubMed1997

Visual integration of data and basic motor skills under laparoscopy. Influence of 2-D and 3-D video-camera systems.

BACKGROUND: The qualities of visual perception and of motor reaction to the visual stimulus have never been studied in reference to the type of video-camera system (2-D vs 3-D) used during laparoscopy. METHODS: The study was designed in two parts. The first evaluated the ability of the eye to discriminate how objects are spaced relative to one another. The second investigated the motor reaction to the visual stimulus in an environment where depth was the preponderent cue. The tests were performed in a pelvi-trainer in which were inserted different modules built either for visual observation (Part 1) or for evaluation of motor ability (Part 2). Variables studied during Part 1 were the time required to do the test and the number of errors committed during its performance. The variable evaluated during Part 2 was the time needed to terminate the test. Each of these two parts of the study were completed alternating the 2-D and 3-D systems. A total of 304 observations were recorded. Statistics used were the paired t-test, the independent group t-test, and the Newman-Keuls multiple comparisons test. RESULTS: Results of Part 1 of the study confirm that visual perception varies significantly among individuals (n = 10) (p < 0.05) and that a true 3-D video-camera system facilitates visual perception when compared to a 2-D system (p < 0.001). Results of Part 2 of the study also show significant differences among participants (n = 9)(p < 0.05). The true 3-D system allowed significantly faster motor performances than the 2-D system (p < 0.001). CONCLUSION: Our experiment shows that the 3-D system allowed significant improvements in the execution of the evaluated parameters. Also noted were significant differences among participants in term of visual and motor skills.

Humans↗
PubMed1997

Comparative genomic hybridization detects genomic abnormalities in 80% of follicular lymphomas.

Comparative genomic hybridization (CGH) was used to analyse 34 follicular lymphoma (FL) samples. 27 samples showed DNA sequence copy number changes of at least one genomic region (26 samples with at least one gain and nine with at least one loss). Some chromosomes or chromosomal regions were preferentially involved. The most frequently gained regions were chromosome 18q (29% of samples), chromosome X (21%), chromosome 7 (18%), chromosomes 2, 6p and 8q (12%). Two regions were preferentially lost: 6q (12%) and 17p (9%). All these gained and lost regions have been previously reported in cytogenetic studies, confirming the accuracy of CGH in detecting genetic abnormalities in FL. 21% of samples displayed normal profiles, probably reflecting the absence of unbalanced abnormality, which is also in agreement with the cytogenetic data. In conclusion, we showed that CGH is an accurate, reliable and rapid method and we propose the inclusion of CGH in the evaluation of FL at diagnosis.

Chromosome Aberrations↗
PubMed1997

Qualitative and quantitative analysis of HLA-DRB gene expression.

Determination of the molecular mechanisms influencing HLA-DRB gene expression would allow better understanding of the regulation of the immune response in normal as well as in pathological conditions. We started an extensive sequencing analysis of the proximal promoter regions of the DRB genes and observed a nucleotide polymorphism involving the classical regulatory regions of the DRB promoters. These nucleotide substitutions were observed to induce variations of the promoter activities as assessed by chloramphenicol acetyl transferase assays and the quantification of DRB transcripts. Similar analysis performed in patients with rheumatoid arthritis strongly suggests dysregulation of HLA-DRB gene expression.

Alleles↗
PubMed1996

[Ontogenesis of lateralities. A review and attempted interpretation].

The present paper offers an updated review on lateralization development in normal children. Instead of just citing a voluminous litterature, we prefer to present an interpretation which perhaps is too synthetic but which tries to go beyond the frequent contradictions encountered within experimental studies as well as between the studies themselves. Results plead for a double movement in the human development, first towards a species-specific asymmetry, then towards a differentiated symmetry. We propose different advantages for the development of human competencies and for the underlying neuro-behavioural organization: asymmetry corresponds to phases in the intrahemispheric cerebral organization and symmetry to phases of interhemispheric synergy.

Brain↗
PubMed1996

[Post-transplantation of Hodgkin's disease. Clinico-pathologic study of 3 cases].

As a frequent complication of immunosuppression, lymphoproliferative disorders affect approximately 2 % of allorgan transplant recipients. Most of them are EBV-associated-B-cell-lymphoproliferations. Other types of non Hodgkin's lymphomas and Hodgkin's disease, as observed in general population, have only rarely been reported in this group of patients. We report three cases of Hodgkin's disease, which were diagnosed in two renal transplant recipients and one heart transplant patient. They were associated with Epstein-Barr virus, as demonstrated by immunohistochemistry and in situ hybridization. EBV is frequently associated with Hodgkin's disease in the general population, and always implicated in AIDS-related Hodgkin's disease. However in transplant patients the rarity of Hodgkin's disease argues against a direct oncogenic role of this virus.

Adult↗
PubMed1996

[Hemophagocytic syndromes. A series of 23 cases].

Inappropriate macrophage activation is responsible for clinical, biological and histological features characterized by diffuse non malignant histiocytic tissue infiltration called "reactive hemophagocytic syndrome" (RHS). We report here 23 new cases. Immunodepression (10 cases), hematologic malignancies (13 cases) and infection (10 cases) are the most favorable conditions associated with RHS. In many cases, several conditions were present at time of diagnosis of RHS and increased its severity. Mechanisms of RHS remains unclear, but cytokine may play a role. Outcome is variable, but death is the most common issue (17 deaths in our series related to RHS). Corticosteroids, etoposide can improve some situations. Further study is needed to establish the role of cyclosporine A or allogenic bone marrow transplantation.

Adolescent↗
PubMed1996

Experimental laparoscopic aortobifemoral bypass for occlusive aortoiliac disease.

OBJECTIVE: To describe a totally laparoscopic technique for aortobifemoral bypass to treat aortoiliac atheromatous occlusive disease. DESIGN: A feasibility study. SETTING: A university teaching hospital. SUBJECTS: Six piglets weighing between 70 and 80 kg were submitted to a totally laparoscopic retroperitoneal aortobifemoral bypass, performed through six trocar sites, with abdominal suspension and a gasless technique. No minilaparotomy was performed. After systemic heparinization, the infrarenal aorta was cross-clamped and the aortic bifurcation stapled. An end-to-end aorto-prosthetic anastomosis was performed. Retroperitoneal tunnels were created to allow each limb of the graft to join its corresponding femoral artery by a conventional anastomosis. INTERVENTION: Totally laparoscopic aortobifemoral bypass. MAIN OUTCOME MEASURES: Duration of the procedure, intraoperative blood loss and operative complications, bleeding in the immediate postoperative period. Evaluation of the aortic anastomosis at autopsy. RESULTS: All aortobifemoral bypasses were completed in less than 4 hours. Intraoperative blood loss did not exceed 250 mL. No intraoperative complication was encountered except occasional bleeding at the aortic anastomosis upon releasing the arterial clamp. This was controlled with a collagen sponge (three cases) or extra stitches (two cases). The animals were observed for 15 minutes before sacrifice. Autopsy revealed a normal aortic anastomosis in all cases and a normal progression of the limbs of the graft under the ureters in the retroperitoneal tunnels. CONCLUSIONS: This animal model demonstrates the feasibility of the aortobifemoral bypass through a laparoscopic approach. The retroperitoneal anatomy of the piglet is similar to that of man. Aortic surgery can be conducted as for the standard technique. We used a similar approach to perform the first human, totally laparoscopic aortobifemoral bypass with an end-to-end anastomosis.

Anastomosis, Surgical↗
PubMed1996

[Histopathologic features of cytomegalovirus lymphadenitis in the "immunocompetent" patient. Report of 7 cases].

The authors report seven cases of cytomegalovirus lymphadenitis in apparently immunocompetent patients. One patient presented with an infectious mononucleosis-like illness. The main presentation of the others was isolated cervical lymphadenopathies. The lymph node pathology showed aspecific lymphoid hyperplasia, resembling the human immunodeficiency virus related lymphadenopathy, associated with diagnostic inclusion cells. Infected cells were confined to areas of monocytoid B cell hyperplasia in all cases whereas exceptionally observed in germinal centers. Because of their variable appearance, serial sectioning was frequently necessary to disclose their characteristic features. In all cases, immunohistochemistry using an anti-cytomegalovirus antibody was positive and revealed more infected cells than detected by morphology alone. Except for the endothelial cell, the nature of infected cells remained undetermined. An alteration of the antigenic expression as a consequence of cell infection might be responsible for immunohistochemistry failure in the cell characterization.

Adult↗
PubMed1995

Stimulation, data acquisition, spikes detection and time/rate analysis with a graphical programming system: an application to vision studies.

A Macintosh-based system performs stimulus control and data acquisition, and an off-line analysis, in experiments on visually driven neurons in frog. The stimulus is a target moved on a modified XY recorder. The computer is equipped with a multifunction input/output board to perform stimulus control and data acquisition. The graphical programming system LabVIEW 2 was used to develop the 'Vision 93' package made of 4 main 'virtual instruments' (VIs). By means of DOCS-Exp, the user controls the experiment via screen displays which look like front panels of electronic instruments. DOCS-Preproc performs a user-controlled spike detection and computes mean impulse rate values. DOCS-SAS displays the instantaneous frequency, mean impulse rate, spike counts or interspike time intervals as staircase histograms and/or spline smoothed curves. Finally, DOCS-x-Functions computes and graphs quantitative stimulus/response relationships in terms of velocity, diameter, orientation and configuration of the target. The functionalities of these main VIs are presented and original software components are detailed. System operation is illustrated by using the successive VIs to process a sample signal record.

Algorithms↗
PubMed1995

Responses of ipsilateral retino-tectal (type I1) units of the frog (Rana esculenta) to moving configurational bars.

In frogs, retinal information projecting to the ipsilateral optic tectum uses a complex, at least bi-synaptic, route. Ipsilateral visual units recorded at the tectal level correspond to isthmic axon terminals. For a better approach of their visual function, these units have been stimulated with moving (V = 7.6 degrees/sec) configurational stimuli proved earlier to be able to elicit classical behavioural sequences in amphibians. In the presence of W("worm-like")-stimuli of increasing length (2 degrees < L < 20 degrees), the discharge rate of type I1 units remains rather constant. In response to A("antiworm-like")-stimuli, the discharge rate first increases up to L = 5-6 degrees and then decreases continuously. The ability of these units to discriminate bars of equal dimension but of different configuration was defined using the "contrast-like" formula originally proposed by Ewert et al. (1978). The relationship between the discrimination factor D(W, A) and the length of the stimuli is similar in shape to that found in class R3 ganglion cells. Results suggest thus that the classical functional homology between type I1 ipsilateral units and class R2 retinal neurons is inadequate.

Animals↗
PubMed1995

Transplants of embryonic cortical tissue placed in the previously damaged frontal cortex of adult rats: local cerebral glucose utilization following execution of forelimb movements.

Transplantation of fetal cortical tissue into the motor cortex of adult rats was used as an experimental model to examine the functional integration of homotopic fetal neocortical grafts into the motor pathways of adult host brain. We have employed the [14C]2-deoxy-D-glucose method to analyse the metabolic activity of the transplant and host sensorimotor cortex: (i) in animals solicited to perform specific lever-pressing movements with the limb contralateral to the transplant (experimental group); and (ii) in non-solicited animals or in animals using the limb ipsilateral to the transplant (control group). Grafts in the control group displayed homogeneous uptake of 2-deoxy-D-glucose throughout the rostrocaudal extent of the transplant. The local cerebral glucose utilization levels were low as compared to those of the surrounding cortex but were at least two-times higher than in the corpus callosum. Increase in 2-deoxy-D-glucose uptake by the transplant cells was found only in the experimental group. In this group, 2-deoxy-D-glucose uptake was higher in the caudal (AP: +3.0 to +1.7 mm, relative to Bregma) than in the rostral sectors of the transplants suggesting the existence of a topographic organization within the transplant. In addition, except in the rostral part, glucose utilization was higher in the transplant of the experimental group than in the sensorimotor areas of the non-activated cortex in the control group. Moreover, glucose utilization of the transplant cells was systematically higher in the experimental than in the control group. The transplants appear to display a certain level of metabolic integration with the host sensorimotor cortex since, in the experimental group, there was no significant differences in local cerebral glucose utilization values in the caudal sector of the transplant and in the surrounding sensorimotor cortical areas of the host. The 2-deoxy-D-glucose uptake was even higher in the caudal sector of the transplant than in some of the subfields of the contralateral sensorimotor cortex. The present findings indicate for the first time that motor activation of the contralateral forelimb produces an increase in metabolic activity in distinct transplant sectors, the topographic distribution of which matches the normal topographic organization of the forelimb somatomotor map. This suggests that transplants of embryonic frontal neocortex placed in the frontal cortex of adult hosts become functionally integrated with the host motor system.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗