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F Gaillard

Publications and source records attributed to F Gaillard.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1995

[Breast cancer and hMG treatment: is there a relationship?].

The promoter effect of oestradiol in breast cancer, the higher risk of breast cancer in infertile nulliparous women and the increased use of treatments to include ovulation would suggest that the risk of cancer after this type of treatment might be affected. We thus evaluated the files of patients under 45 years of age treated for breast cancer at the Bergonié Foundation. Six such cases were found. Due to the small number of cases observed to date, no statistical analysis could be performed. Nevertheless, several cases may have gone unrecognized or unpublished. Two hypothesis might be involved: the facilitating effect of stimulation on infraclinical or undiagnosed cancers, initiation of new cancers. We thus propose: a register to follow treated women in order to monitor the appearance of new cases of cancer, improved surveillance in patients with other associated risk factors.

Adult↗
PubMed1995

[Abdominal lymphomas in children: place of surgery].

To determine the place of surgery in the management of abdominal Burkitt's lymphoma, we retrospectively reviewed the records of 17 children treated over a period of 10 years (1983-1992). Patients were 14 males. Seven patients presented with acute abdominal pain, 6 with an abdominal mass and 5 with intestinal obstruction. In 3 cases, the diagnosis was made without laparotomy (2 percutaneous tumoral puncture, 1 pleural puncture). In the 14 other cases, the diagnosis was made by laparotomy with 3 biopsies and 11 resection of the tumor (7 complete and 4 incomplete). These laparotomies were complicated by 1 evisceration and 2 intestinal obstruction. At the end of the initial chemotherapy, 1 children was reoperated for a residual mass with no histological viable tumor. Sixteen children were long term survivors (14 > 2 years); 1 died. Surgery was indicated in cases of intestinal intussusception. In cases of abdominal mass, surgery could have been avoided twice (positive ascitic fluid). A complete tumoral resection had no influence on survival which depend of extra-abdominal extension and more over of response to chemotherapy.

Abdominal Neoplasms↗
PubMed1994

Testicular tumor and the acquired immunodeficiency syndrome.

Immunocompromised patients, particularly those suffering from the acquired immunodeficiency syndrome (AIDS), present an increased risk of tumoral pathology. From the observation of a testicular lymphoma associated with Epstein-Barr virus in a HIV + patient, we review 19 cases of testicular tumor in HIV + patients previously published in the literature. These tumors are either lymphomas (4 cases) or germ cell tumors (15 cases). Their diagnosis was not difficult, although in the first stages enlarged and painful testicles are often wrongly identified as orchiepididymitis and treated as such. Therapy management proves to be delicate as a result of the significant tumor spread seen in these patients with dysfunctional immune systems. Regarding lymphomas, a low-dose multiagent chemotherapy with intrathecal chemotherapy was recommended by Levine. Concerning germ cell tumors, Wilson prefers an instant aggressive treatment with retroperitoneal lymphadenectomy (whether or not combined with chemotherapy) to avoid the risk of recurrence. In fact, tumor relapses will be difficult to control in the progressive stages of immunodeficiency syndrome.

Adult↗
PubMed1993

[The role of adrenal gland x-ray computed tomography and scintigraphy using radiolabelled norcholesterol in the etiological diagnosis of primary hyperaldosteronism].

The major etiologies of primary aldosteronism are aldosterone-producing adrenal adenoma, requiring a surgical treatment, and bilateral hyperplasia, usually managed with medical therapy. We only report a retrospective study on 22 patients with primary aldosteronism diagnosed by clinical and usual biochemical tests. All the patients were explored by computed tomography scan (CT) and iodomethyl-norcholesterol scintigraphy. The purpose of this study was to compare the capacity of the two methods to differentiate adrenal adenoma and hyperplasia. The CT scan was more sensitive (sensitivity: 88%) compare to scintigraphy (sensitivity: 64%) for the diagnosis of adrenal adenoma. However, the scintigraphy was a useful tool to detect asymmetric macronodular adrenal hyperplasia. Therefore, the catheterisation of adrenal venous would be only necessary for a few cases. We conclude from this study and the literature review that CT scan and iodomethyl-norcholesterol scintigraphy are complementary and both useful to increase diagnostic reliability of primary aldosteronism.

19-Iodocholesterol↗
PubMed1993

[Extramedullary hematopoiesis. An unusual cause of Pagetic spinal cord compression].

An original case is reported: spinal cord compression due to extramedullary hematopoiesis of the epidural space, related to Paget's disease of bone, successfully treated by surgery. Extramedullary hematopoiesis, usually occurring in cases of hematological disease, can also complicate Paget's disease, probably by bone effraction mechanism. A review of literature has found 5 other cases of extramedullary hematopoiesis occurring in Paget's disease, without hematological disease. Medullar scintigraphy (Indium111, Technetium99 Sulfur colloid) can confirm the diagnosis after X-ray findings, without the need for biopsy. Awareness knowledge of this complication can sometimes avoid invasive investigation. Low dose radiotherapy is useful in the case of hematological disorders. In Paget's disease, there is a risk of sarcomatous degeneration. In our patient, surgery cured cord compression, but it relapsed because of extensive fibrosis, in complicating surgical hemorrhage.

Aged↗
PubMed1992

Primary Epstein-Barr virus infection with clonal T-cell lymphoproliferation.

A case of fatal Epstein-Barr virus infection in a previously healthy girl who was first found to have severe infectious mononucleosis with spontaneous recovery is reported. Because an abnormal immune response to the virus persisted, the disease relapsed, manifesting in cutaneous and pulmonary lesions associated with hemophagocytic syndrome responsible for death. Pathologic findings were characterized by polymorphous atypical lymphoid infiltrate, prominent necrosis, and histiocytic hyperplasia. Lymphoid cells displayed CD8 phenotype and clonal T-cell receptor gene rearrangement. Viral genome was detected in lesions by Southern blot and located in nuclei of lymphoid cells by in situ hybridization. Pathologic findings suggested fatal infectious mononucleosis; however, phenotype and genotype favored a malignant diagnosis. Clonality was demonstrated to have arisen during primary infection. Virologic examination indicated that Epstein-Barr virus was a causative agent. Such a process belongs to the recently recognized spectrum of Epstein-Barr virus-related T-cell lymphoproliferative disorders that might overlap fatal infectious mononucleosis in patients who are especially vulnerable to the virus.

Adolescent↗
PubMed1992

Immunohistochemical detection of cells positive for colony-stimulating factor 1 in lymph nodes from reactive lymphadenitis, and Hodgkin's disease.

Colony-stimulating factor 1 (CSF-1) is a cytokine involved in hematopoiesis and perhaps more importantly in the early stages of immunological defense mechanisms. Although numerous studies of in vitro CSF-1-producing cells have been published, in vivo data is totally lacking. According, we performed immunohistochemical detection of CSF-1-positive cells on frozen sections of reactive lymphadenitis (three cases) and Hodgkin's disease (13 cases) lymph node biopsies, using as antibody a highly specific polyclonal rabbit antiserum prepared in our laboratory. Endothelial cells from high endothelial venules and most fibroblasts were positive in all cases (reactive lymphadenitis and Hodgkin's samples), and most lymphocytes in interfollicular T cell areas showed faint granular positivity in reactive lymphadenitis lymph nodes. Hodgkin and Reed-Sternberg cells were positive in all cases tested, although staining intensity was highly variable and the percentage of positive cells differed from case to case. These data from in vivo biopsies confirm previous results for in vitro CSF-1 production by endothelial cells, fibroblasts, T lymphocytes, and Hodgkin cell lines. They are consistent with the role of this cytokine in immune response and raise the question of its significance in Hodgkin's disease.

Hodgkin Disease↗
PubMed1991

[Vertebral compressions revealing Cushing's syndrome. 3 cases].

The authors report three cases of osteoporotic vertebral fractures in the Cushing Syndrome. This osteoporosis is partially reversible after treatment of the cause. Laboratory findings must comport a cortisonuric and a 17 hydroxycorticosterone cycle.

Adult↗
PubMed1990

[Prognostic and therapeutic aspects of lympho-epithelial lesions of the parotid. Apropos of 8 cases].

The so-called benign lympho-epithelial lesion (BLEL) of the parotid is a rare condition. Its diagnosis is based on histology. For a long time there have been problems with its classification and prognosis: classification since certain cases may be classified as Sjögren's syndrome or as a precursor of the latter, prognosis there may be recurrence, contralateral involvement or progression to non-hodgkin's lymphoma. The authors discuss these factors in 8 cases and propose total parotidectomy with facial nerve preservation as the treatment of choice.

Adult↗
PubMed1989

Quantitative studies on ipsilateral type 2 retinotectotectal (IRTT) units in frogs: homologies with R3 ganglion cells.

Contralateral and ipsilateral responses from deep layers of the rostral neuropil of the optic tectum of Rana esculenta were recorded extracellularly and quantitatively analyzed. Effects of the velocity and diameter of the stimulus on the neuronal response (measured as the mean firing frequency, R) were mainly tested in this work. 1. Among the population of changing contrast or event ganglion cells, R3-like units (with a weak response to background off-on stimulation) were defined in addition to typical R3 ganglion cells. 2. A power function relating R and the stimulus velocity (v) was established in all units (R = k v alpha), with alpha = 0.80-1.07 and k = 2.1-9.5 for R3 units, alpha = 0.55-0.77 and k = 5.8-15.2 for R3-like units, and alpha = 0.80-1.16 and k = 1.3-5.1 for ipsilateral I2 units. 3. The area function was expressed by a logarithmic function. In all classes the maximal response was obtained with 4.4 degrees-7.5 degrees targets, independent of the test velocity. 4. Both the velocity and the diameter of the stimulus influenced the value of the dynamic receptive field diameter. 5. Finally, results show that qualitative and quantitative properties of I2 units are similar to those of R3 ganglion cells.

Action Potentials↗