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G Bernard

Publications and source records attributed to G Bernard.

13 recordsLinked to original sources
PubMed1992

Age-dependent alteration in regional cerebrovascular permeability during drug-induced epilepsy.

Age-related changes in blood-brain barrier permeability were investigated during pentylenetetrazol-induced seizures in rats aged from 15 days to 120 days. Tracers such as [14C]sucrose and [3H]inulin which diffuse very slowly across the intact endothelium were simultaneously injected i.v. in rats treated with pentylenetetrazol (PTZ) or in control animals. Permeability-surface area products (PA) were determined in 9 brain regions. Pentylenetetrazol-induced seizures caused a significant increase in PA for both sucrose and inulin in all brain regions studied. Blood-brain barrier dysfunction was present only in animals in which the mean arterial blood pressure rose at seizure onset. Although increased blood-brain barrier permeability was found partly in similar areas in both young and adult rat brains, in adults the increase was the highest in the preoptic area, septum, colliculus inferior, hypothalamus and in the cerebellum while the increase was comparatively much smaller in the same areas of young brains. The increase in blood-brain barrier permeability was extremely high in the hippocampus, hypothalamus and cerebellum of 15-day-old rat brain and, was least affected in the corpus striatum and cerebral cortex in contrast to older rats. From the results obtained it may be concluded that the increased cerebrovascular permeability induced by pentylenetetrazol differs markedly in localization in young and adult rats. The age-dependent increased blood-brain barrier integrity is not over all dependent on variations in the blood pressure, but rather on progressive maturation of capillaries and changes in their internal structure, and local phenomena in neuronal activity during the seizures.

Aging↗
PubMed1991

Initial process of diffusion of small molecules from blood vessels to the meninges in the young rat.

Pathways taken by peripherally administered small molecules when entering the brain were investigated in 6-day-old rats by radioautography and fluorescence microscopy after intravenous administration and rapid freezing. L-[U-14C]Phenylalanine, [U-14C]sucrose and sodium fluorescein reached the brain within less than 5 seconds. These blood-borne molecules were found in the subarachnoid cisterns and the superficial parenchyma. These results suggest a special permeability of the arachnoid layer and/or the pial vessels. Phenylalanine alone reached the deep parenchyma because of the existence of a specific endothelial carrier.

Animals↗
PubMed1990

Blood-brain barrier permeability: regional alterations after acute and chronic administration of ethinyl estradiol.

In this study we measured the effect of acute and chronic estrogen treatment on cerebrovascular permeability to sucrose and inulin. Animals were subcutaneously injected once with 0.1 micrograms/rat of ethinyl estradiol or injected daily with the same drug dose for 3 weeks. Control rats received the same amount of arachis oil vehicle. Three weeks treatment but not the single injection of ethinyl estradiol produced significant increases in the cerebrovascular permeability-surface area product for sucrose and inulin in almost all brain regions.

Animals↗
PubMed1990

Luminal CCK-releasing factors in the isolated vascularly perfused rat duodenojejunum.

The factors operating at the apical side of the endocrine cell releasing cholecystokinin (CCK) were investigated using the isolated vascularly perfused rat duodenojejunum. In the protease-free intestinal segment, a 30-min infusion of glucose (280 mM), oleic acid (100 mM), or triglycerides containing short- or long-chain fatty acids did not alter significantly the basal level of portal CCK-like immunoreactivity (CCK-LI), while octanoic acid (100 mM) produced a transient rise of plasma CCK-LI to approximately 250% of basal. Infusion of proteins (5% solutions of ovalbumin or casein) or of a mixture of all amino acids brought about a modest CCK secretion. In contrast, isocaloric amounts of an ovalbumin hydrolysate produced a sharp rise of portal CCK-LI to 530% of basal followed by a well-sustained plateau secretion (420% of basal) until the end of the infusion. An acid casein hydrolysate induced a slightly less pronounced CCK-LI release and was followed in decreasing order by meat, casein, and soybean peptones. Simultaneous infusion of trypsin with ovalbumin or casein hydrolysate reduced by approximately 60% the CCK release induced by peptone alone. This effect was reversed by coinfusion of soybean trypsin inhibitor (SBTI) with the trypsin-peptone mixture. Arterial infusion of tetrodotoxin (10(-6) M) or atropine (10(-5) M) had no significant effect on the trypsin-induced inhibition of peptone-mediated CCK-LI release. Administration of SBTI or camostate alone or in combination with trypsin did not alter basal CCK. Monitor peptide produced a dose-dependent transient rise of portal CCK-LI over the range from 2 to 12 micrograms.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1990

Studies of an antiendotoxin antibody in preventing the physiologic changes of endotoxemia in awake sheep.

In sheep, endotoxin (LPS) causes pulmonary hypertension, hypoxemia, leukopenia, exudation of protein-rich lung lymph, reduced dynamic compliance (Cdyn), and increased resistance to airflow (RL), changes similar to those seen in human sepsis and sepsis-induced ARDS. We used well-described methods in the awake sheep-endotoxin model to evaluate the effectiveness of a commercially manufactured antibody to prevent the physiologic changes of endotoxemia. In awake sheep with chronic lung lymph fistulas, we used a whole-body plethysmograph to measure Cdyn, RL, and FRC. Pulmonary artery, left atrial, and systemic arterial pressures were recorded continuously. Arterial blood gases (for calculating AaPO2), leukocyte counts, and lymph samples were collected every 30 min. Animals received a 30-min (2 mg/kg) infusion of antiendotoxin antibody 4 h before LPS (0.75 micrograms/kg) challenge (n = 4), or were given a mixture of LPS (0.75 micrograms/kg) and antibody (2 mg/kg) that had been incubated in vitro at 37 degrees C for 30 min before infusion (n = 6). A control group given only 2 mg/kg of antibody (n = 4) showed no change in any measured parameter, whereas control animals receiving LPS alone (n = 6) exhibited a typical endotoxin response. In all animals receiving endotoxin, Cdyn declined by approximately 50% within 30 to 60 min, and RL increased approximately sixfold over a similar time course. Accompanying the abnormalities in lung mechanics were pulmonary hypertension, leukopenia, and widening of the AaPO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Effect of dimethyl sulfoxide on blood-to-brain transfer of alpha-aminoisobutyric acid: examination of regional blood-brain barrier function.

The effect of dimethyl sulfoxide (DMSO) on brain capillary permeability has been controversial. We have studied the effect of DMSO on unidirectional transport of alpha-aminoisobutyric acid (AIB) across the blood-brain barrier (BBB) in rats. Rats were treated with 15% DMSO intraperitoneally (i.p.), intravenously (i.v.) or by an i.p. injection in combination with an i.v. injection, or in some cases intra-arterially by rapid infusion into left external carotid artery. The unidirectional blood-to-brain transfer constant (Ki) for AIB was measured in each group after the animals were killed. DMSO administration did not significantly increase Ki as compared to control Kj. These results show that it is unlikely that DMSO increases the permeability of BBB and therefore do not support the proposal that DMSO can act as a carrier at the BBB for compounds with restricted vascular permeability.

Aminoisobutyric Acids↗
PubMed1978

[Local synthesis of immunoglobulins in pleural effusions. II].

A report is given about the synthesis of IgG immunoglobulins in the pleural infiltrations. The quantity of immunoglobulins locally yielded is estimated through the ratio IgG/Albumin in the blood and in the infiltration. Evidence is given that the mechanic and neoplastic transudates are easily detectable on account of the failed local synthesis of immunoglobulins of IgG type. A short account is given of the local synthesis of IgA.

Humans↗
PubMed1977

Clioquinol.

Explore the source record for details and available documents.

Benzoates↗
PubMed1977

[Advantages of the combination of the technics of double arc precipitation analysis and of scaled dilutions in the study of asymptomatic monoclonal gammopathies].

A report is given about the opportunity and the advantages of combining the traditional scheme for the study of the pathological immunoglobulins with the analysis of the uncoupling of the bow of precipitation against IgG and the isolation of the pathological immunoglobulin through a diluition of the serum such as to bring the fraction electrophoretically dispersed to not detectable levels and make it detectable the monoclonae portion electrophoretically homogeneous.

Humans↗
PubMedDate not supplied

Blockade of bombesin receptors with [Leu14-psi(CH2NH)-Leu13]bombesin fails to suppress nutrient-induced CCK release from rat duodenojejunum.

The present study was undertaken in order to delineate the contribution of enteric bombesin (BBS)-containing nerves in the food-induced release of intestinal cholecystokinin (CCK). For this purpose, the isolated vascularly perfused rat duodenojejunum model was used and the new compound [Leu14-psi(CH2NH)-Leu13]BBS was infused intraarterially at a concentration of 10(-6) M to block the BBS receptors. Vascular infusion of BBS alone (10(-8) M or 10(-9) M) provoked a dose-dependent release of CCK-like immunoreactivity (CCK-LI). The secretion pattern of CCK was biphasic and consisted of a transient peak (300-400% above basal) followed by a sustained response (200-300% above basal). Vascular coinfusion of the BBS analogue with BBS 10(-9) M completely abolished both phases of CCK release while only the second phase of CCK secretion was profoundly reduced upon coadministration of BBS 10(-8) M with the BBS receptor antagonist. Luminal administration of mixed nutrients induced a prompt and well-sustained release of CCK-LI which was unaffected upon arterial infusion of the BBS analogue. These data suggest that the intestinal supply in BBS-producing nerves is not involved in the food-induced release of intestinal CCK in the rat.

Animals↗
PubMedDate not supplied

[Comparative study of the efficacy and acceptability of amineptine and fluoxetine in patients with major depression].

We compare two anti-depressant drugs, amineptine and fluoxetine, in a multicentric study. Amineptine is a dopamine reuptake inhibitor, and fluoxetine a serotonin reuptake inhibitor. Eighteen french centers participate in the study. One hundred and sixty nine outpatients were randomly assigned to either 200 mg of amineptine or 20 mg of fluoxetine during 90 days. They fulfilled the DSM III-R criteria of major depressive disorder. They were aged from 18 to 70. Minor tranquilizers were allowed during the study. The patients were evaluated at D0, D7, D21, D42 and D90. If possible, an additional evaluation was made at D4. Clinical evaluations included Clinical Global Investigation (CGI), Montgomery and Asberg Depressive Rating Scale (MADRS), HARD scale, Widlocher Retardation rating scale and Hopkins Symptom Check-list (HSCL). Somatic concerns were recorded at each visit. Among the 169 patients included in the study, only 141 ended it at D90. The two drugs had good antidepressive efficacy which was noticed as soon as D7 up to D90. If we compare the antidepressant activity, no statistical differences could be observed between the two drugs using different scales. The percentage of patients with an improvement of at least 50% of the global score at MADRS was 8.3% at D7; 41% at D21, 69.2% at D42 and 83.2% at D90 for the amineptine group. For the fluoxetine group, these percentages were, 7.7%; 37.8%; 78.9%; 82.1%. No statistical differences could be noticed between the two groups, and at any time of the study. We have tried to look for a rapid antidepressive action by a clinical evaluation at D4.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗