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Biomedical subjects

A Sebille

Publications and source records attributed to A Sebille.

At least 37 records · Page 2Linked to original sources
PubMed1990

Low prevalence of cisplatin-induced neuropathy after 4-day continuous infusion in head and neck cancer.

The toxicity of cisplatin on peripheral nerves was studied using electrophysiologic recordings in 52 patients with head and neck squamous cell carcinoma. Induction chemotherapy (cisplatin: 25 mg/m2/day, days 1-4; 5-fluorouracil: 1 g/m2/day, days 1-4) was administered by continuous infusion every 3 weeks. Electrophysiologic recordings were performed before and after the completion of three courses of chemotherapy (cisplatin total dose: 250-300 mg/m2). The comparison between the recordings showed 14% of the patients had an increase in the latency of the soleus muscle monosynaptic reflex as studied by the Hoffman reflex and 9% showed a decrease in the conduction velocity of the cutaneous sensory fibers of the median nerve. These results indicated a low prevalence of cisplatin-induced neuropathy. The respective roles played by the continuous infusion of the drug and by the potentiation of neurotoxic effects resulting from the association of cisplatin with other neurotoxins is discussed to explain this low toxicity.

Adult↗
PubMed1989

Conditioning lesion effects on rat sciatic nerve regeneration are influenced by electrical stimulation delivered to denervated muscles.

The rate of regeneration and the initial delay of the fastest growing fibers of the rat sciatic nerve were electrophysiologically evaluated after a freeze at mid-thigh. A prior section or a prior freeze at the ankle level increased the rate of regeneration and decreased the initial delay with different magnitudes. These phenomena are named 'conditioning lesion effects'. A daily electrical stimulation transcutaneously delivered to the foot sole muscles from the day following their denervation by the prior lesion did not modify the increased rate of regeneration but prevented the decrease of the initial delay whatever the type of the prior lesion. Therefore, the initiation of earlier sprouting of the parent axons seems to be specifically controlled by a signal associated with muscle denervation properties.

Animals↗
PubMed1989

[Direct electric stimulation of the denervated posterior cricoarytenoid muscle triggered by subglottic temperature in the cat. Preliminary to a laryngeal pacemaker].

Using a temperature sensor to detect inspiratory fresh air flow in the subglottis, we triggered direct electrical stimulation of unilaterally denervated posterior cricoarytenoid muscle (PCA) in cats. Respiratory air flow temperature variations were recorded in awake animals and stimulation of the PCA resulting in vocal cord abduction was obtained several weeks after surgery. Difficulties related to chronic implantation and stimulation are discussed. Their solutions are required before laryngeal pacemaker is used.

Animals↗
PubMed1988

Electrophysiological study of conditioning lesion effects on rat sciatic nerve regeneration following either prior section or freeze. II. Blocking by prior tenotomy.

The conditioning lesion effects refer to the earlier formation and the accelerated regeneration of axonal sprouts following two successive axotomies. In a previous study, we observed that a prior freeze or a prior cut of rat sciatic nerve resulted in differences in the enhancement of the regeneration rate and the reduction of the initial delay. These differences were interpreted as a possible non-neuronal cells influence on the intrinsic regulation of the conditioning lesion phenomenon. In the present study, we attempted to modify the status of the muscles using tenotomy before the prior nerve injury to determine the respective influence of the muscular cells on conditioning lesion effects. Thus, the conditioning lesion, which was either a cut or a freeze of the tibial nerve at the ankle, was performed 14 days after foot sole muscles were tenotomized, close to their insertion into the calcaneus bone. The test lesion was always a freeze of the sciatic nerve at midthigh performed 7 days following the prior lesion. The elongation of the regenerating sprouts was electrophysiologically evaluated and the regeneration rate as well as the initial delay were calculated by means of regression analysis. Tenotomy did not influence the regeneration as was demonstrated in a group with a single sciatic nerve lesion. In contrast, when prior lesion was performed, the tenotomy prevented both the enhancement of the rate of regeneration and the reduction of the initial delay, whatever was the type of the conditioning lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

A blind trial of silicone chamber fluid in nerve regeneration in the rat.

The nerve growth-promoting effects of the fluid accumulating in vivo from 1 to 28 days within silicone chambers were tested on the sciatic nerves of rats. We measured the elongation of sensory axons following nerve transection repaired by means of fibrin sealant allowing local application of the fluid. We found no difference between transections treated with chamber fluid and controls.

Animals↗
PubMed1987

Dapsone-induced neuropathy compounds Hansen's disease nerve damage: an electrophysiological study in tuberculoid patients.

In 17 previous cases of dermatological disorders, an axonal motor neuropathy was described as a dapsone (DDS) therapy side effect. In this study, we attempted to assess DDS-induced neuropathy in the ulnar and popliteal nerves of 39 tuberculoid Hansen's disease patients using electrophysiological recordings at the time of DDS withdrawal, owing to dermatological improvement, and 4 months after. Distal motor latencies, conduction velocities at forearm and leg and above the epicondyle and the neck of the fibula were improved at a highly significant level. Twenty-five percent of the patients presented abnormal values (outside of the 95% confidence interval) at the first recording session compared to those at the second session. By contrast, parameters exploring the degree of innervation of distal muscles showed a progressive denervation. These results lead to an impairment of Hansen's disease neuropathy during DDS therapy affecting the motor conduction velocities of one quarter of the patients, and are discussed in terms of physiopathological mechanisms.

Adolescent↗
PubMed1986

Electrophysiological study of conditioning lesion effect on rat sciatic nerve regeneration following either prior section or freeze. I. Intensity and time course.

A peripheral nerve lesion performed distally prior to a proximal axotomy is known to result in an increase in the rate of regeneration of both sensory and motor fibres. This phenomenon is called the 'conditioning lesion effect'. The aim of this study was to determine whether or not the kind of the conditioning lesion influences the intensity and the time course of the conditioning lesion effect. The prior lesion was performed on the tibial nerve of rats at the ankle either by cutting the nerve or freezing it by means of a 1 mm diameter liquid nitrogen cryod. At several points in time up to 28 days a second (or test) lesion consisting of a freeze was performed on the sciatic nerve at the middle part of the thigh. The regeneration of the fastest growing fibres of the sciatic nerve was measured electrophysiologically 5, 7 and 9 days after the test lesion. The nerve was surgically removed, immediately mounted in a recording nerve chamber and stimulated proximally to the test lesion. The distance between the test lesion and the most distal point where an evoked nerve potential was detectable was taken as the regenerated nerve length. Then the rate of regeneration was calculated and the initial delay was estimated by means of a linear regression plotting the regenerated nerve lengths against the days of recording. All the results were compared to those of a control group where the test lesion alone was performed. The increase in the maximal rate of regeneration was greater following a prior section (+25%) than following a prior freeze (+12%). Following a prior section, the rate of regeneration began to be significantly increased for a conditioning interval of 4 days, and went on until a conditioning interval of 28 days. By contrast, after a prior freeze the rate of regeneration was significantly increased solely for an interval of 14 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Nerve regeneration in exogenous cerebral ganglioside-treated rats.

Intraperitoneal injection of 50 mg/kg of exogenous cerebral gangliosides resulted in a statistically significant (23%) increase (compared with saline-injected controls) in the tetanic isometric tension of the rat plantaris muscle 7 days after section of the fourth lumbar root (L4). In a second experiment, intraperitoneal-injected exogenous gangliosides were found to have no effect on axonal regeneration following cryo-injury to the sciatic nerve. These results lead to the possibility of an early enhancement of muscular collateral sprouting in partially denervated muscles under an intraperitoneal-injected ganglioside mixture treatment.

Animals↗
PubMed1984

Axon regeneration and vascularisation of nerve grafts. An experimental study.

An experimental model has been designed to assess the effect of vascularisation on axon regeneration in nerve grafts. The vascular status of the grafts has been demonstrated by microangiography and histology. Rat sciatic nerve grafts in which the vascular pedicles were left intact retained a normal vascular pattern which was not adversely affected by wrapping the graft in a polythene sleeve. In devascularised grafts, revascularisation commenced at three days and was complete at nine days. If the devascularised grafts were wrapped in a polythene sleeve, revascularisation was impeded and at fifteen days the middle segment of the graft was avascular and infarcted. The rate of axon regeneration was measured electrophysiologically in the above four groups of nerve grafts. There was a linear relationship between the rate of axon regeneration with time post-graft, axon growth proceeding at a mean rate of 1.150mm/day (S.E. +/- 0.084) after a mean delay of 4.85 days. There was no significant difference in the rate of axon regeneration in the four groups.

Animals↗
PubMed1984

Electrophysiological studies of the sciatic nerves in Mycobacterium leprae foot pad-injected rats.

This study tested the possibility of developing an experimental model of neuropathy in female Wistar rats inoculated with Mycobacterium leprae in the foot pad and assessed by repeated electrophysiological methods. M. leprae multiplied in the rats but considerably less than in simultaneously inoculated mice. No acid-fast bacilli were found in nerves. Motor and sensory conduction velocities remained normal at the thigh level of the sciatic nerve. At the leg, they decreased significantly bilaterally for motor conduction and in the inoculated side for sensory conduction at 21 months after inoculation. These results suggest the possibility of developing an experimental model of leprosy neuropathy which might be useful for therapeutic research. Further histopathological studies are needed to assess this paucibacillary model.

Animals↗
PubMed1982

[Detection of peripheral diabetic neuropathy. A reappraisal of electrophysiological data].

In addition to motor and sensory nerve conduction, monosynaptic triceps surae reflex, amplitude of median nerve voltage and response of extensor digitorum brevis and soleus muscles were investigated in 29 diabetic patients. These parameters were altered earlier than motor and sensory nerve conduction, which considerably increased the incidence of subclinical peripheral neuropathy (90% of the patients). It was also found that sensory fibers were affected earlier than motor fibers. The electrically detected neuropathy correlated with duration of diabetes and control of glycaemia.

Axons↗
PubMed1982

[Peripheral neuropathies. Current data concerning nerve regeneration (author's transl)].

The peripheral neuropathies in humans could be classified both with clinical criteria and pathological aspects. Between these, only axonal neuropathies are subject to regeneration. Axonal neuropathies present two aspects: wallerian degeneration and dying-back neuropathy. Dying-back neuropathy is the commonest type of human neuropathy but wallerian degeneration has been the most studied model of axonal neuropathy. The regeneration in this case lead to two questions: what is the signal for regeneration and what are the factors which improve the nerve growth?

Animals↗
PubMed1982

[Acceleration by isaxonine of muscle reinnervation. Electrophysiological demonstration in leprotic neuropathy (author's transl)].

On a model of compressive human neuropathy--leprous neuropathy occuring below an osteoligamentary canal following a process of sclerosis--a double-blind survey of isaxonine versus a placebo was undertaken after matching of patients to obtain similar pairs. After four months of treatment with isaxonine, the electrophysiological tests (EMG of the anterior tibialis and of the abductor digiti minimi muscle) showed a very significant improvement in the graphs of patients receiving the active agent, as compared to a lack of improvement, even an aggravation for those patients receiving the placebo. It may thus be concluded that muscular reinnervation has occurred, either by sprouting of the remaining healthy fibers or by regeneration of the damaged axons, or by both phenomena simultaneously.

Adolescent↗
PubMed1982

[Neurotoxic substances as a tool to understand some mechanisms of peripheral neuropathies (author's transl)].

The study of toxic experimental models of neuropathies has been a decisive step to understand some cellular mechanisms of human neuropathies. The progressive development of toxic neuropathies allow to the possibility of isolating their initial mechanism. Dying back axonopathies are the commonest neuropathies as observed in clinical practice, and their experimental models had been extensively studied. Acrylamide and n-hexane intoxications have shown the following results : 1) The onset of the neuropathy is located at the most distal node of the longest and largest fibres. Sensory fibres are impaired before the motor ones. 2) Fast axoplasmic transport stops distally. 3) Impaired enzymes of the energetic cycle were observed distally. Proximal axonopathies as those resulting from IDPN intoxication are a possible model to clear up the cellular mechanisms of the lateral amyotrophic sclerosis. Human toxic neuronopathies and myelinopathies are uncommon. Such experimental models are described in relation to other human neuropathies.

Acrylamides↗
PubMed1981

[The early phase of vincristine-induced neuropathy. Electrophysiological evidence of a "dying-back" phenomenon (author's transl)].

Electrophysiological exploration was carried out in 12 patients before and during administration of vincristine sulphate 1,4 mg/m2 body surface area. The patients had stage III or IV lymphoreticulosarcoma and received one injection of vincristine weekly for 6 weeks. Compared with pretreatment findings, (1) motor and sensory conduction velocity, as well as delay in triceps surae H reflex remained unchanged; (2) sensory nerve amplitude and density of distal muscle electromyographic recordings rapidly decreased; (3) the amplitude of distal tendinous reflexes rapidly diminished, whereas that of the H reflex remained stable. These results being similar to those observed in experimental acrylamide toxicity, where a "dying back" hemopathy has been demonstrated, it is suggested that the neuropathy induced by vincristine in man is of the same type.

Acrylamides↗