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Biomedical subjects

D Bentue-Ferrer

Publications and source records attributed to D Bentue-Ferrer.

At least 37 records · Page 2Linked to original sources
PubMed1989

Comparative evaluation of scavenger properties of exifone, piracetam and vinburnine.

The involvement of radical reactions in the ageing process, physiological as well as pathological, is well demonstrated. It is accepted that alloxan cyto-toxicity is linked to a production of hydroxylated free radicals and that a substance preventing the development of alloxanic diabetes possesses scavenger properties. The objective of this work was to demonstrate, in this model, the anti-radical effect of 3 molecules recommended in the treatment of cerebral insufficiency and a reference substance (+)-catechin. We observed a protective action with catechin (P less than 0.05) at the highest dose (100 mg/kg). PEG alone was moderately active but comparison of PEG-alloxan and PEG-exifone-alloxan showed a highly significant difference (P less than 0.001) at the two highest doses (60 and 120 mg/kg). Piracetam (200 and 400 mg/kg) and vinburnine (7.5 and 15 mg/kg) were inactive. Under these experimental conditions, exifone demonstrated remarkable anti-radical properties.

Animals↗
PubMed1989

[Chemotherapy combined with Lipiodol. In vitro study of the kinetics of release of adriamycin].

Intra-arterial injection of lipiodol-adriamycin mixtures are commonly used in the treatment of hepatic tumors based on the progressive release of adriamycin. This study was undertaken to assess, in vitro, the influence of mixture formulations on the adriamycin release pattern. Eight mixtures containing 10 mg of adriamycin were tested. Adriamycin was tested in solution (mixture A) in suspension (mixture B), or in emulsions with Hexabrix 320 (mixtures C to F). Ratios between Hexabrix and lipiodol volumes were 2/1, 1/1, 1/2, and 1/4 for emulsions C, D, E, and F, respectively. Emulsions G and H corresponded to emulsions E and F, with Arlacel A as emulsifying agent. All mixtures were prepared in triplicate and added with water. Samples of 200 microliters were taken from the aqueous phase after 10, 20, 30 min, 1, 2, 4, 8, 24, 48, 72, and 120 h for adriamycin dosage. Lipiodol-adriamycin mixture formulation significantly influenced the release pattern of adriamycin. Three formulations (suspension, emulsions 2/1 and 1/4) induced the most progressive release of adriamycin from lipiodol. This release was dramatically retarded by the addition of an emulsifying agent.

Delayed-Action Preparations↗
PubMed1989

Pharmacology of the memory process.

Rather than reviewing once again the published literature on drugs which are capable of modifying the memory process, the authors stress the methodological difficulties which impede the development of such products. At the moment, substances which act on neurotransmission systems, and in particular cholinergic and gabaergic agents, seem to be good candidates. The choice of the molecule to be studied in man depends on the neurochemical physiopathology of the memory disorder which one seeks to correct. For this reason, one tries to select an animal model of memory which is closest to the clinical situation pertaining to man on which the tested molecule might act favorably.

Animals↗
PubMed1988

Randomized, double-blind trial of exifone versus cognitive problems in Parkinson's disease.

Exifone is a novel substance of the benzophenone group that possesses potent scavenging properties. Initial findings demonstrate beneficial effects on age-related cognitive disorders. In this double-blind clinical trial versus placebo, the efficacy of 2 dosages (600 and 1200 mg/d) was evaluated with regard to Parkinson's disease (PD)-related cognitive disorders, for which there is increasing suspicion of a free-radicals origin. Despite disparities between the treatment groups as assessed by validated scales and subtests, and a considerable placebo effect on main parameters, both dose levels of exifone produced statistically significant improvement of the cognitive items most commonly impaired by PD: immediate recall, naming of objects presented, spatiotemporal orientation, and calculation. These properties suggest a new slot for exifone in the range of therapeutics available.

Aged↗
PubMed1987

[Cerebral edema: intra-cellular or extra-cellular mechanisms?].

Many cerebral pathological processes are attended by edema defined as an increase in brain volume associated with an increase in brain water and sodium contents. The aggravation of lesions induced by this edema warrants a pharmacological and therapeutic approach based on a detailed knowledge of its physiopathological mechanisms. Experimental models and in vitro studies have shown that the fundamental mechanisms leading to edema are: cold, acute hypoxia, ischaemia, arachidonic acid, toxic substances and plasma hypo-osmolarity. To the various types of edema described (vasogenic, cytotoxic, hydrocephalic) correspond different mechanisms. Vasogenic edema essentially depends on osmotic and hydrodynamic factors; cytotoxic edema results from perturbations in energy-dependent cellular osmoregulation. The underlying biochemical disorders have now been demonstrated, mostly in ischaemic edema; they include, during the revascularization phase, disruption of the blood-brain barrier (vasogenic component) and changes in ion concentrations, neurotransmitters and energetic mechanisms. Key factors in the development of edema are cyclic AMP, serotonin and Na-K-ATPase.

Animals↗
PubMed1984

Impairment of acquired temporal response regulation of rats under normobaric hypoxia.

Effects of hypoxia on learning involving temporal regulation of behaviour was investigated. Under 10% hypoxia there was a decrease in the number of conditioned responses, and the 'efficiency' of reinforcement, but no modification of temporal discrimination. Normobaric hypoxia may be a useful model for studying certain behavioural and pharmacological effects of cerebral circulatory insufficiency, and their implications at the level of the central nervous system, but it would be incorrect to use such a model to study factors that might prevent the loss of acquired knowledge.

Animals↗
PubMed1983

[Epidural anesthesia using the bupivacaine-fentanyl combination for cesarean section].

This prospective study was designed to evaluate the benefit of a bupivacaine-fentanyl mixture vs bupivacaine alone in epidural anaesthesia for caesarean section. In 10 women, 0.5% bupivacaine (1.18 ml per metamer) was injected in the epidural space. In 20 women, 0.5% bupivacaine (1.06 ml per metamer) was injected by the same route together with fentanyl (1.70 +/- 0.09 micrograms X kg-1). The bupivacaine-fentanyl group showed a significantly shortened onset of analgesia (p less than 0.001), as well as a significant reinforcement of this analgesia graduated from 0 to 4 (p less than 0.01 at 25 min, p less than 0.001 at 75 min and at the maximum of pain, for the two sets of scores). All the Apgar scores were maximal at 5 min. No clinical respiratory depression was observed in either the mothers or the neonates. Fetal and maternal blood concentrations were in favour of respiratory innocuousness of the method (peak fentanyl concentrations: in mothers 1.5 ng X ml-1, in neonates 0.8 ng X ml-1). Fentanyl never induced any significant haemodynamic variations. Pruritus and nausea respectively occurred in six and two patients respectively in the bupivacaine-fentanyl group. In conclusion, in caesarean section, the adjunction of fentanyl to bupivacaine significantly improved analgesia without any clinical respiratory depression both in the mother and the neonate.

Adult↗
PubMed1983

[Undesirable dermatologic results of drugs. Result of a drug monitoring survey].

A prospective survey of drug-induced diseases has been performed along a one year period in a department of dermatology. Among the 550 patients hospitalized during this period for a cutaneomucous event, a drug-induced disease is pointed out in 30 of them (5.6 p. cent). The use of algorithm allows the establishment of the cause-effect relationship; the relative value of literature data and the role of three main predisposing factors (age, allergic antecedents, polymedication) are insisted upon. Three categories of drugs are primarily implicated: cardiovascular, antiinflammatory and antiinfectious drugs. The most commonly observed events are erythrodermia and allergic phenomena. If favorable evolution is usual, one fatal adverse drug reaction is firmly established in our series. Such a survey would lead to preventive attitudes.

Adult↗
PubMed1981

[Study of three biocides (dimethoate, parathion ethyl and zineb) on female rat neuro endocrinological balance (author's transl)].

The authors studied the neuro endocrinological effects of three pesticides. Two of them were organophosphorus compounds (ethyl parathion and dimethoate) and one was a carbamate (zineb). Mature female rats have been orally administered these compounds for 16 days at respectively 1/25, 1/10 and 1/10 of the LD50. The parameters recorded are: the gonadotropins, the length of estrous cycle and the weight of the anterior pituitary gland, the ovaries and the uterus. In contradistinction with the organochlorine compounds the organophosphorus did not induce any disturbances in the neuro endocrinological system, whereas the carbamate compound decreased the pituitary gonadotropins.

Animals↗
PubMed1980

The use of bromocriptine for testing central dopaminergic reactivity.

A single oral intake of 10 mg of Bromocriptine can modify both plasma renin activity (PRA) and arterial blood pressure (BP). The changes in both variables depend on the integrity of the central dopaminergic systems. The parkinsonians whose extrapyramidal symptoms are markedly improved by L-Dopa in association with a decarboxylase inhibitor (IDC) and the untreated parkinsonians are the only patients whose PRA and BP are lowered 1 h after Bromocriptine ingestion. The results obtained in the L-dopa-induced dyskinetic parkinsonians are similar to those obtained in the group of L-Dopa-resistant patients. This points to the paradoxical hypothesis of dopaminergic hyposensitivity in the dyskinetic patients. In spite of the absence of correlation between PRA and BP, it is possible that lowering of BP by Bromocriptine is linked to the parallel decrease of PRA. An increase of the BP may be obtained in the dyskinetic and L-Dopa-resistant groups. These data point to a possible involvement of central dopaminergic systems in some aspects of hypertension.

Blood Pressure↗
PubMed1979

[Shy and Drager syndrome. Physiopathological and pharmacological approach based upon one case (author's transl)].

The authors report a new case of Shy and Drager syndrome characterized by the severity of the extrapyramidal signs as well as that of orthostatic hypotension and urinary dysfunction. Peripheral adrenergic disturbance was proven, associated with an abnormality of the renin-angiotensin system. The authors describe the various drugs tried experimentally in treatment of the three main symptoms of the disease. A combination of Trihexyphenidyl and Dibenzepine finally appeared to be the most effective. Six months later, there remained a marked improvement in extrapyramidal signs and orthostatic hypotension. By contrast there was no improvement in urological symptoms.

Basal Ganglia Diseases↗
PubMed1979

Plasmatic renin activity in patients treated with L-dopa and inhibitor of dopa decarboxylase (IDC).

Plasmatic renin activity (PRA) was studied in patients receiving L-dopa, together with a decarboxylase inhibitor, at rest times and after periods of physical exertion. Although we can superimpose the results from unrelated Parkinson's disease patients on those of the control group, the results are inversed in stabilized patients (lowered PRA) and dyskinetic patients (increased PRA). There is a definite correlation between the increase in PRA and intensity of the dyskinesia. Dosage is the only other factor differentiating the two groups of Parkinsonians treated. The figures relative to arterial pressure are studied in the various groups.

Adult↗
PubMedDate not supplied

Drugs used in Alzheimer's disease and neuroplasticity.

Drugs indicated for use in Alzheimer's disease (AD) must clinically improve the cognitive symptomatology of the disorder, although nonexclusively. From a neurochemical standpoint, these drugs must oppose the multiple processes recognized as stigmata of AD. In these two ways, so-called AD drugs may be considered substances modifying cerebral plasticity. Long-term evaluation of anticholinesterases and of tacrine, in particular, provides arguments in support of this initially purely biologic, theoretical approach. This concept of neuroplasticity applied to dementia may modify the traditional pharmaceutical drug development programs.

Alzheimer Disease↗
PubMedDate not supplied

Effect of triethyltin chloride on the central aminergic neurotransmitters and their metabolites: relationship with pathophysiology of aging.

Triethyltin (TET) salt intoxication provokes a myelinic vacuolisation associated with a white matter cerebral edema. The central nervous system disturbances accompanying these phenomena (Na-K-ATPase activity, neurological symptoms, water and sodium cerebral content) can be counteracted by drugs used in age-related brain failure; consequently, TET intoxication could be suggested as an experimental model for studying the aging process. The aim of the present study is to follow-up the biogenic amine concentrations in different brain areas of TET treated rats, knowing that modifications of cerebral amines exist throughout the aging process. The following results are obtained: the cerebral water content of the TET treated rats is significantly increased, confirming the existence of a brain edema. Monoamine concentrations are significantly decreased, specifically noradrenaline (in hypothalamus, mesencephalon, cerebellum); serotonin (in striatum, hypothalamus, mesencephalon); dopamine only in hypothalamus; these are accompanied by an increase of the metabolites 5 HIAA (in striatum and mesencephalon) and HVA (striatum). These modifications are compared to those occurring in physiological aging, and hypothetical mechanisms are reviewed. We conclude that TET intoxication must not be considered as a pathophysiological model of brain aging, but may be considered as a useful pharmacological tool for studying experimental drugs liable to counteract brain age-induced disturbances.

3,4-Dihydroxyphenylacetic Acid↗
PubMedDate not supplied

[Comparative effects of seven beta adrenolytic agents on blood pressure after injection into the posterior hypothalamus of rats. The frequency heart and the plasma renin activity (author's transl)].

The author's studied the central action of seven beta-blocking agents: alprenolol, atenolol, bupranolol, oxprenolol, pindolol, practolol, propranolol. The drugs were stereotactically injected into the posterior hypothalamus of non anaesthesized rats. Three dosages were used. Blood pressure, heart rate and plasma renin activity (PRA) were recorded. 2. The seven beta-blocking drugs used decreased heart frequency for at least one dosages PRA always decreased but blood pressure was lowered only after administration of alprenolol, oxprenolol, pindolol. 3. The discussion deals with: --the specificity of the target, --the involvement of the central beta receptors into the PRA regulation, --the correlations between the cardiovascular responses and the pharmacological properties of the different molecules; the hypothetic role of the intrinsic activity is postulated --the dissociation between heart rate and blood pressure responses, suggesting the existence of two different receptors for the specific control of those two parameters.

Adrenergic beta-Antagonists↗