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Biomedical subjects

B Ferry

Publications and source records attributed to B Ferry.

At least 19 recordsLinked to original sources
PubMed1997

Bicuculline administration into basolateral amygdala facilitates trace conditioning of odor aversion in the rat.

This study investigated the effect of bicuculline methiodide (BMI) microinjection into basolateral amygdala (BLA) on conditioned odor aversion. Bilateral injections of BMI (39 or 59 pmol/0.2 microliter) or artificial CSF were done in the BLA 5 min after the presentation of the conditioned stimulus (water intake at an almond-scented tube). This was followed 30 min later by lithium chloride-induced toxicosis. Whereas under these experimental conditions control rats (CSF injected) did not develop a conditioned odor aversion, BMI-treated rats (59 pmol) did so, suggesting that the blockade of GABAA receptors facilitated this learning. This facilitation was unlikely due to an unconditioned action of BMI, as a group microinjected with 59 pmol of BMI but not intoxicated did not display conditioned aversion. This result suggest that blockade of the GABAA receptors can prolong the olfactory trace duration, making it accessible to association with delayed toxicosis. Combined with previous results, these data support the hypothesis that the GABAergic system of the basolateral amygdala exerts control over the duration of a short-term odor trace in our conditioned odor aversion paradigms.

Amygdala↗
PubMed1997

Noradrenaline modulates glutamate-mediated neurotransmission in the rat basolateral amygdala in vitro.

The entorhinal cortex and the amygdala are interconnected structures of the limbic system in which paroxysmal activity occurs during temporal lobe epilepsy. Conflicting evidence shows that noradrenaline (i) inhibits the spreading to other parts of the limbic system of paroxysmal activity generated in the amygdala or the entorhinal cortex, but also (ii) increases glutamatergic transmission in the basolateral amygdala. Given our previous work on the inhibitory effect of noradrenaline on entorhinal cortex neurons, we developed an in vitro slice preparation to study the synaptic transmission in the basolateral amygdala and its modulation by noradrenaline. Noradrenaline reduced the fast excitatory postsynaptic potential (EPSP) by approximately 40% at 100 microM and the slow EPSP by approximately 50% at 50 microM. A similar effect was obtained with the alpha2-agonist UK 14304 at 100 and 50 microM respectively. In contrast, the beta-agonist isoproterenol increased the fast EPSP by approximately 40% at 100 microM and the slow EPSP by approximately 20% at 50 microM. Accordingly, the effect of noradrenaline on the EPSPs was blocked by the alpha2-antagonist yohimbine (10 microM) but not by the alpha1-antagonist prazosine (10 microM) and the beta-antagonist propranolol (10 microM). Noradrenaline (50-100 microM) was ineffective on most (14/16) of the isolated inhibitory postsynaptic potentials (IPSPs). These experiments provide evidence that noradrenaline inhibits the excitatory synaptic response of basolateral amygdala neurons. A pharmacological analysis revealed that the noradrenergic modulation of the excitatory transmission in the basolateral amygdala can be dissected into a predominant alpha2-adrenoreceptor-mediated inhibition and a beta-adrenoreceptor-mediated excitation.

Amygdala↗
PubMed1996

Facilitation of conditioned odor aversion by entorhinal cortex lesions in the rat.

This study examined the role of the entorhinal cortex (EC) in conditioned odor aversion learning (COA). Lateral EC lesions did not impair but rather facilitated COA. In the experiments the delay separating the odor cue presentation from the subsequent toxicosis was varied during acquisition. EC-lesioned rats demonstrated COA for delays up to 2 hr, whereas sham-operated rats displayed COA only if toxicosis immediately followed the odor cue. This facilitation was not dependent on the intensity of the odor and corresponded to a facilitated long-delay learning. EC lesion did not affect conditioned taste aversion, confirming that the facilitation effect does not correspond to a general facilitation of conditioned aversion learning. Taken together, these results indicate that the removal of the EC may allow odor-toxicosis associations across longer delays by extending the duration of the olfactory trace.

Animals↗
PubMed1996

Inhibition of the transendothelial migration of human lymphocytes but not monocytes by phosphodiesterase inhibitors.

This study describes an in vitro model of peripheral blood mononuclear cell (PBMC) migration through human endothelial cells, held on polycarbonate inserts, which allows automatic differential counting of migrated cells as lymphocytes and monocytes. Using this system it was found that treatment of PBMC with the phosphodiesterase (PDE) inhibitors theophylline (at 1 and 10 micrograms/ml) and RO-20-1724 (at 1 microM) inhibited the migration of the lymphocyte component to 64.2+/-16.4%, 48.9+/-3.0% and 47.5+/-5.8% of the control values, respectively, while the migration of the monocytes component was largely unaffected. The PDE inhibitors needed to be present during the assay to inhibit migration, whereas pre-treatment of either the endothelium or the PBMC did not consistently effect lymphocyte migration. The drugs also inhibited the migration of lymphocytes through control inserts, either uncoated or coated with fibronectin, suggesting that some of the inhibition is an effect on lymphocyte motility rather than lymphocyte-endothelial interactions. Lymphocyte migration through fibronectin-coated filters was significantly enhanced compared with uncoated filters. Activation of the PBMC by anti-CD3 MoAb increased motility and migration by up to 300%. This migration appeared to be greatly inhibited by the PDE inhibitors, although the effect was complicated by problems of lymphocyte aggregation. This study provides a novel method of measuring mononuclear cell transendothelial migration, and suggests a possible role of PDE inhibitors in reducing this progress.

4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone↗
PubMed1996

[Preliminary analysis of the modifications of spinal curves, in extreme amplitudes, observed in rhythmic and athletic gymnastics].

Trained users of Rhythmic and Athletic Gymnastic, present kinetic spinal vast extents. Analysis, with pasted cutaneous markers, shows that, according to the codified movement, various segments of the vertebral column are requested and realized important displacements. Nevertheless, to have an homogeneous attitude, some subjects request more either lumbar or thoracic segments, of both. To prevent frequent spinal pain, it is important to realize a preliminary subject selection using their total spine and to improve protection by adapted gymnastic.

Adaptation, Physiological↗
PubMed1996

[Comparative study of static curves of the human spine in vivo during exercise and stretching in men and women].

Comparative study of static curves of the thoracic and lumbar spine in men and women has been realized under constraints of compression by weightlifting and elongation by exercise to parallel bars. In two athletic practices, curves decrease their arrow, ending to a straighter and more rigid column. This behavior expresses muscular actions. The greatest amplitude of displacement, observed in female series, shows lesser muscular forces in connection with a poor practice of exercises of body building.

Adaptation, Physiological↗
PubMed1995

Neuroanatomical and functional specificity of the basolateral amygdaloid nucleus in taste-potentiated odor aversion.

The present study aimed at documenting the neurobiological substrate of taste-potentiated odor aversion (TPOA) in the rat. The role of several temporal lobe structures in discriminative TPOA learning was questioned. The effects of excitotoxic lesions (ibotenate) of the basolateral amygdaloid nucleus, the central amygdaloid nucleus, the caudate putamen nucleus, and aspirative lesion of the entorhinal cortex were studied. The results show that only basolateral amygdaloid nucleus (ABL) damage impaired TPOA. This effect was selective of TPOA, since it spared conditioned taste aversion (CTA) and olfactory perception. In order to find out which process in TPOA requires normal functioning of the ABL, the effects of microinjections of a GABAA agonist (muscimol) into the ABL at various stages of the experiment were examined. The results show that application of muscimol during the acquisition, before or after the presentation of the odor-taste stimulus, impaired TPOA without affecting CTA. Contrastingly, application of muscimol before the test impaired neither TPOA nor CTA. These results suggest that ABL is involved in the acquisition but not in the retrieval of TPOA. The efficacy of muscimol microinjected after the presentation of the odor-taste stimulus further suggests that the deficit is not due to a sensory impairment but rather to the disruption of a memory process, critical for TPOA.

Amygdala↗
PubMed1995

Sexual behaviour in developing countries: implications for HIV control.

OBJECTIVE: To provide basic information on pre- and extramarital sex in the general population and other factors related to HIV transmission. DESIGN: Cross-sectional household survey in 18 countries of the developing world, mainly in Africa and Asia. RESPONDENTS: Representative samples of 1300-6995 individuals aged 15-49 years, interviewed in 1989-1993. METHODS: Face-to-face interviewing. RESULTS: We observed a huge variability between study sites, with the proportion of men reporting sexual contact outside regular partnerships in the last year ranging from 4 to 47%. Contacts with sex workers range from 1 to 25%. Women were much less likely to report non-marital sex than men. CONCLUSIONS: This first cross-cultural attempt to examine aspects of sexual lifestyles suggests that broad generalizations about multiple-partner sexual networking in particular regions are misleading. Gender, marital status, age and a few other demographic correlates were disclosed as powerful determinants of sexual behaviour, although the strength of associations varied greatly between specific locations. Condom use was very low in most study sites.

Adolescent↗
PubMed1991

[Utilization of health statistics in peripheral structures in developing countries].

Health information in developing countries serves mostly to diseases notification and activity registration, but rarely is it used for analyzing the health status of populations or the results of health intervention. Moreover, it is stored at a national level, mainly to fill monthly or yearly reports, and very seldom at a peripheral level where it would be probably more helpful. On the basis of experiences realized in Senegal and Nepal, we try to answer the two following questions: how to make health statistics utilizable, i.e. which criteria of relevance and quality recommend and how to utilize them concretely where they are produced, taking into account their well known limits?

Data Interpretation, Statistical↗
PubMed1987

Tumour aneuploidy, prognostic parameters and survival in primary breast cancer.

Cellular DNA content of primary tumours from 280 patients with operable breast cancer was determined by flow cytometry using nuclei from paraffin sections stained with DAPI, and 199 of these patients were followed for 8-13 years after surgery. Tumours from 67 patients have also been analyzed for their DNA content using single cell suspensions from fresh tumour tissue stained with mithramycin and ethidium bromide, and the results compared with those obtained from paraffin blocks of the same tumours. Overall 60% of the tumours contained cells with abnormal DNA content (DNA-aneuploid populations). Survival and disease free interval were not significantly different in patients with DNA-diploid and DNA-aneuploid tumours when analysed by Mantel's life table method. There was however, an early advantage for patients with DNA-diploid tumours: during the first 30 months after surgery DNA-aneuploidy was associated with higher rate of recurrence and shorter survival. DNA-aneuploidy was strongly related to histological grade. Thus 11/49 (22%) grade I, 60/102 (59%) grade II, and 96/129 (74%) grade III tumours were DNA-aneuploid. Although there was no significant difference in survival of patients with DNA-diploid and DNA-aneuploid tumours overall, there appears to be an unexpected association between DNA-aneuploidy and better survival in grade II patients (P less than 0.01); a similar trend was observed for grade I patients. Although the proportion of DNA-aneuploid tumours was similar in oestrogen receptor positive and negative tumours, DNA-aneuploidy was associated with lower levels of oestrogen receptors in comparison to DNA-diploid tumours. Comparison between the modal DNA values of fresh and paraffin embedded samples showed high rate of comparability (64/67, P less than 0.0001).

Aneuploidy↗
PubMed1987

Impact of class II major histocompatibility complex antigen expression on the immunogenic potential of isolated rat vascular endothelial cells.

We have investigated the immunogenic potential of rat heart vascular endothelial cells by their ability to induce an accelerated rejection of a relevant heart allograft, and related the immunogenic potential to the expression of class II major histocompatibility complex (MHC) antigens on the endothelial cell surface. Only 12% of freshly isolated rat vascular endothelial cells express class II antigens in serum-free medium, and the level of expression is low as judged by immunoperoxidase staining and/or the ability of endothelial cells to bind staphylococci to the cell surface after treatment with monoclonal antibodies to the class II molecule. On the other hand, 99% of the endothelial cells under the same conditions express class I, and the level of expression is high. The class II antigen expression of vascular endothelial cells can be upregulated to more than 98% by recombinant gamma-interferon in vitro--and, concomitantly, the level of expression becomes high, even on the cell surface. Treatment with gamma-interferon did not substantially alter the level of class I expression. The endothelial cells expressing class II antigens weakly, are also weakly immunogenic in vivo: 10(7) endothelial cells are required to reduce the graft survival by 50% of that of the unprimed host. On the contrary, the endothelial cells of the same lineage induced to express class II antigens by gamma-interferon in vitro are highly immunogenic in vivo, as immunogenic as freshly-isolated spleen dendritic cells: only 10(4) endothelial cells are required to induce a 50% reduction of graft survival. These observations demonstrate for the first time that rat vascular endothelial cells are immunogenic in a primary transplantation response in vivo--and, moreover, that the immunogenic capacity of the endothelial cells is directly proportional to the extent of class II MHC antigen expression on the cell surface.

Animals↗
PubMed1987

Frequency and functional characterization of specific T-helper cells infiltrating rat kidney allografts during acute rejection.

T-helper cells (ThC) play an important role in the induction of both cytotoxic T-cell responses and B-cell responses against the grafted organ. Furthermore, ThC alone are capable of causing graft rejection in T cell-deprived mice and rats. In view of these observations we found it important to analyse the frequency and functions of donor-specific ThC in the allograft and in the recipient lymphoid system during the course of acute renal allograft rejection. A limiting dilution assay was developed which, due to the absence of exogenous interleukin 2 (IL-2) and the low numbers of stimulator cells used, appears to be highly selective for the proliferation of specific ThC. Kidney transplants were performed from LBN (RT1n) to congenic Lewis (RT1l) strain differing in major histocompatibility complex (MHC) only. The inflammatory (white) cells were recovered from the graft, and blood and recipient spleen and the frequency of RT1n-responding ThC were determined at different times after transplantation. In the kidney graft itself, the frequency of ThC responding to RT1n MHC antigens was 1:3000 on day 2 and increased to 1:670-1320 at the peak of inflammation. In the spleen, the frequency increased from 1:1000 on day 0 to 1:200 on day 8, and remained high even after the graft was rejected. In the blood, the frequency stayed at the 1:400-1:800 level, and increased to 1:200 only after the graft had been completely destroyed. Individual ThC clones deriving from limited dilution assays of kidney and spleen cells were recovered and expanded with irradiated donor cells without IL-2 and finally with exogenous IL-2 only. All clones showed the T-helper (W3/25) phenotype, seven out of eight tested clones showed a specific anamnestic response to RT1n alloantigens and no response to RT1l or RT1a in a secondary MLC, 12 out of 12 clones produced IL-2 and 11 out of 11 clones produced gamma interferon upon re-stimulation with relevant allogeneic cells, and eight out of ten clones collaborated with syngeneic B cells for Ig synthesis, indicating that they were indeed derived from specific ThC and/or from their precursors. Taken together, the results demonstrate that specific ThC and/or their precursors represent only a very small minority in the graft-infiltrating inflammatory population. This makes it most unlikely that the ThC themselves are responsible for graft destruction; the results indicate rather that a major role of ThC in situ may be instruction of immunologically specific and nonspecific components of inflammation.

Animals↗
PubMed1986

Antagonistic effects of gamma interferon and steroids on tissue antigenicity.

A single injection of 10(5) U/kg of recombinant rat IFN-gamma increases the amount of tissue dendritic cells up to sixfold, and concomitantly induces the (capillary) endothelial cells to express class II MHC antigens. Both responses peak on the third day after IFN-gamma injection, and the antigen expression returns to basic levels on day 7. Simultaneous administration of 1 mg/kg/d of methylprednisolone entirely abolishes both responses. These observations demonstrate, for the first time, that IFN-gamma and steroids have antagonistic effects on class II MHC antigen presentation in tissue, and suggest that one immunosuppressive mechanism of glucocorticosteroids in organ transplantation is downregulation of graft antigenicity.

Animals↗