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Biomedical subjects

L Pain

Publications and source records attributed to L Pain.

At least 19 recordsLinked to original sources
PubMed2005

[Systemic Candida albicans infection with neuromeningeal complication in a premature infant].

INTRODUCTION: Systemic maternal-fetal Candida albicans infections are uncommon diseases with a poor outcome. An associated cerebromeningeal infection increases morbidity. We present a case of neuromeningeal candidiasis following systemic neonatal infection in a premature infant. Management and therapeutic difficulties are outlined. OBSERVATION: The patient was a male infant born preterm at 30 weeks gestation. During his first week of life, he developed a systemic infection with an associated symptomatic hydrocephalus. Systemic candidaisis with neuromeningeal complication was diagnosed five weeks later. Despite treatment including cerebrospinal fluid (CSF) shunting and antimycotic medications (flucytosin and amphotericin B), the candidal infection did not resolve. Infectious and mechanical complications of the CSF drainage were treated by several surgical interventions during the following months. At 10 months of life, there was clinical and laboratory evidence of active persistent neuromeningeal candidaisis. Finally, candidal infection was eradicated with intravenous administration of fluconazole. After five year follow-up, the intellectual and psychological status of the patient was quite satisfactory, and no neurological deficits were found on clinical examination. DISCUSSION: Management of neuromeningeal candidaisis in premature infants is a challenging task particularly because of delayed diagnosis. Candida infection should routinely be suspected in cases of systemic infection with neurological impairment in premature infants. Fluconazole may constitute an efficient therapeutic option.

Amphotericin B↗
PubMed2002

Mechanisms of action of midazolam on expression of contextual fear in rats.

BACKGROUND: Midazolam may suppress conditioned fear after an aversive event by disrupting the memory trace formed during conditioning, by altering the emotional part of the aversive event, or by the combination of both effects. The purpose of the present study was to determine whether affective-related processes contribute to the amnesic-like effects of midazolam on aversive events. METHODS: The effects of acute administration of low doses of midazolam (0.37-3 mg kg(-1)) on fear conditioning (association between a neutral context and an aversive stimulus) and on innate anxiety in fearful surroundings were examined in rats. The effect of midazolam on the deleterious consequences of pre-exposure to the context (a non-aversive event) for subsequent fear conditioning was then compared with its effect on fear conditioning. The role of midazolam as an affective context was assessed by performing the testing phase under midazolam. Possible locomotor impairment or long-term effects of midazolam were controlled in additional experiments. RESULTS: Midazolam reduced both contextual fear conditioning and spontaneous fear. The deleterious effect of midazolam on pre-exposure to the context was of the same magnitude as its effect on the acquisition phase of fear conditioning. The effects of midazolam on both pre-exposure to the context and fear conditioning were unchanged when rats received a second injection of midazolam before the retention phase. CONCLUSIONS: Low doses of midazolam that do not impair locomotion suppress conditioned fear to the context by acting on memory processes rather than on affective or anxiolytic processes.

Analysis of Variance↗
PubMed2000

Combined lesions of cholinergic and serotonergic neurons in the rat brain using 192 IgG-saporin and 5,7-dihydroxytryptamine: neurochemical and behavioural characterization.

This study assessed behavioural and neurochemical effects of i.c.v. injections of both the cholinergic toxin 192 IgG-saporin (2 microgram) and the serotonergic toxin 5,7-dihydroxytryptamine (5,7-DHT; 150 microgram) in Long-Evans female rats. Dependent behavioural variables were locomotor activity, forced T-maze alternation, beam walking, Morris water-maze (working and reference memory) and radial-maze performances. After killing by microwave irradiation, the concentrations of acetylcholine, monoamines and 5-hydroxyindoleacetic acid (5-HIAA) were measured in the hippocampus, frontoparietal cortex and striatum. 192 IgG-saporin reduced the concentration of acetylcholine by approximately 40% in the frontoparietal cortex and hippocampus, but had no effect in the striatum. 5,7-DHT lesions reduced the concentration of serotonin by 60% in the frontoparietal cortex and 80% in the hippocampus and striatum. Noradrenaline was unchanged in all structures except the ventral hippocampus where it was slightly increased in rats given 192 IgG-saporin. Cholinergic lesions induced severe motor deficits but had no other effect. Serotonergic lesions produced diurnal and nocturnal hyperactivity but had no other effect. Rats with combined lesions were more active than those with only serotonergic lesions, showed motor dysfunctions similar to those found in rats with cholinergic lesions alone, and exhibited impaired performances in the T-maze alternation test, the water-maze working memory test and the radial-maze. Taken together and although cholinergic lesions were not maximal, these data show that 192 IgG-saporin and 5,7-DHT lesions can be combined to selectively damage cholinergic and serotonergic neurons, and confirm that cholinergic-serotonergic interactions play an important role in some aspects of memory, particularly in spatial working memory.

5,7-Dihydroxytryptamine↗
PubMed2000

Central cholinergic depletion induced by 192 IgG-saporin alleviates the sedative effects of propofol in rats.

We examined the effect of central cholinergic depletion on the sedative potency of propofol in rats. Depletion was produced by intracerebroventricular administration of an immunotoxin specific to cholinergic neurones (192 IgG-Saporin; 2 microg). As a result of this lesion, acetylcholine concentration was reduced by about 40% in the frontoparietal cortex and in the hippocampus but was essentially normal in the striatum and cerebellum. Sedation in rats was assessed as the decrease in locomotor activity. Sedative potency of propofol (30 mg kg(-1) i.p.) was reduced by about 50% in rats who received the injection of 192 IgG-Saporin as compared to controls. These results show that a central cholinergic depletion alleviates the sedative effect of propofol, and indicates that basal forebrain cholinergic neurones might mediate part of the sedative/hypnotic effects of propofol.

Acetylcholine↗
PubMed1999

Effect of nonsedative doses of propofol on an innate anxiogenic situation in rats.

BACKGROUND: The effect of propofol on anxiety has not been well studied. In humans, such investigations are confused by the fact that sedation often coexists with anxiolysis. Therefore, the authors evaluated the effects of minimal sedation with propofol in rats placed in an innate anxiogenic situation, the elevated plus-shaped maze. METHODS: In experiment 1, spontaneous locomotor activity was determined in rats as a measure of sedative effect induced by propofol (0-9 mg/kg administered intraperitoneally). In experiment 2, groups of rats received propofol (0-9 mg/kg) or diazepam (0-2 mg/kg) and then were placed on a plus-shaped maze elevated above the ground that was composed of two opposite closed arms and two opposite open arms. On an initial exposure to the maze, undrugged rats avoid the open arms, with the number of entries into and time spent within the open arms constituting approximately 20% of their total activity. This reflects normal anxiety in a rodent for any elevated open platform. RESULTS: In experiment 1, 0-9 mg/kg propofol did not alter spontaneous activity in rats. In experiment 2, propofol and diazepam significantly increased the number of entries into and the time spent within the open arms. Propofol at a dose of 9 mg/kg significantly increased the rats' level of exploration of the open arms to about 50% of all exploratory activity, and a similar observation was made with 2 mg/kg diazepam. CONCLUSIONS: In a standard animal model, propofol has anxiolytic properties at doses that do not produce sedation.

Animals↗
PubMed1998

The anxiolytic effect of gamma-hydroxybutyrate in the elevated plus maze is reversed by the benzodiazepine receptor antagonist, flumazenil.

The effects of gamma-hydroxybutyrate (GHB), a product of gamma-aminobutyric acid (GABA) metabolism which possesses neuromodulatory properties in brain, were investigated in the elevated plus maze in rats. The number of entries and the time spent in the open arms of the maze were increased by GHB (50, 150, 250 mg/kg i.p.). This is classically considered as indicative of an anxiolytic effect of the drug. There was no sedative effect at these doses as measured by the spontaneous locomotor activity in the actimeter or the total number of arm entries. The anxiolytic properties of GHB were reversed by neither the GHB receptor antagonist, NCS-382 (6,7,8,9-tetrahydro-5(H)-5-olylidene acetic acid) (300 mg/kg i.p.), nor the opioid receptor antagonist, naloxone (10 mg/kg i.p.). However the anti-anxiety effect of GHB was antagonized by the benzodiazepine receptor antagonist, flumazenil (10 mg/kg i.p.), suggesting an interaction of GHB with the GABA(A) receptor complex which mediates the anti-anxiety effect of benzodiazepines.

Animals↗
PubMed1998

[The sitting position in neurosurgery: the viewpoint of the surgeon].

The sitting position offers the benefits of better access to the apex of the posterior fossa, and an improved exploration and dissection because blood and cerebral spinal fluid drain away from the operative site. Specific complications of the sitting position include cardiovascular instability, jugular venous obstruction, airway oedema, quadriplegia, displacements of catheters and the endotracheal tube, ulnar, sciatic and lateral peroneal nerve compression, venous air embolism, and tension pneumocephalus. In the only existing comparative study, the differences were an increased bleeding in the horizontal position and a better cranial nerve preservation in the sitting position. This argues strongly for teaching and use of the sitting position whenever surgically indicated.

Humans↗
PubMed1998

[Intracranial surgery in the lateral position].

The lateral posture (Park Bench) is now widely used. It provides a comfortable position for the surgeon and a convenient brain relaxation. However the positioning is complex and carries a risk of stretching of the brachial plexus. Spatial orientation is more difficult and requires surgical experience. The lateral position does not modify the haemodynamic and respiratory function in healthy patients. In the opposite, various cardiac or respiratory effects of right or left lateral position can occur in patients with cardiac and/or respiratory pathology.

Anesthesia↗
PubMed1997

Early assessment of transplanted liver function: lignocaine clearance test (MEGX).

The purpose of this study was to assess the value of lignocaine biotransformation into monoethylglycinexylidide (MEGX) and conventional liver function tests in the early post-operative period as an indicator of graft function and as a diagnostic tool for complications after hepatic transplantation. Monoethylglycinexylidide formation, plasma bilirubin, aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), factor V index (FVI) and prothrombin time index (PTI) were measured in 71 patients undergoing 80 liver transplantations respectively at 12 (T1), 24 (T2), 48 (T3) and 72 h (T4) after liver graft revascularization. Patients were divided into two group according to the post-operative outcome. Patients with favourable outcome (n = 59) had significantly higher monoethylglycinexylidide synthesis, higher factor V index and prothrombin time index plasma concentrations, lower bilirubin, ASAT and ALAT plasma concentration (P < 0.0001 at T2 and T3) than those with complicated time course (n = 21). Monoethylglycinexylidide synthesis was the best discriminant of a favourable outcome, whereas bilirubin and ALAT concentrations were associated with complications (bilirubin for primary non function [PNF], ALAT for acute rejection). Thus, the combination of parameters at T2 was a very efficient predictor of primary non function, acute rejection and an uncomplicated time course.

Anesthetics, Local↗
PubMed1997

Effect of midazolam on propofol-induced positive affective state assessed by place conditioning in rats.

BACKGROUND: The effect of either midazolam or the combination of midazolam and propofol on the affective state was assessed in rats at subanesthetic doses and at recovery from anesthesia. METHODS: The putative drug(s)-induced affective states were repeatedly paired with one of two distinguishable compartments of an experimental cage, whereas the vehicle(s)-induced effect was repeatedly paired with the other compartment. During a subsequent choice test for one compartment over the other, the rats' preference for the drug(s)-paired compartment over the vehicle(s)-paired compartment is indicative of a pleasant state induced by the drug(s). In experiment 1, rats were conditioned with different doses of midazolam either at subanesthetic states or at recovery from anesthesia. In experiment 2, groups of rats were conditioned with different combinations of midazolam and propofol either at subanesthetic states or at recovery from anesthesia induced jointly by midazolam (10 mg/kg) and propofol (60 mg/kg). Experiment 3 was conducted in the same way as experiment 2, except that midazolam was paired with both compartments. In addition, these groups were tested not only in an undrugged state but also in a drugged (with midazolam) state. RESULTS: In experiment 1, rats exhibited a place preference for the environment previously associated with midazolam, at subanesthetic and anesthetic doses. Experiment 2 showed that a propofol-induced place preference was found to be dose-dependently suppressed by midazolam. Experiment 3 replicated the findings of experiment 2 and extended them to the mechanism by which midazolam blocked a propofol-induced place preference. CONCLUSIONS: Midazolam administered before propofol blocked the expression of a propofol-induced pleasant state.

Affect↗
PubMed1996

Effect of propofol on affective state as assessed by place conditioning paradigm in rats.

BACKGROUND: Whether propofol produces a pleasant affective state remains unclear from clinical studies. In the current study, the effect on affective state of subanesthetic and anesthetic doses of propofol was assessed at a preclinical level with rats in a place conditioning paradigm. Propofol was compared with methohexital. METHODS: In the place conditioning paradigm, propofol-induced effect was repeatedly paired with one of two distinguishable compartments of the apparatus, whereas the vehicle-induced effect was repeatedly paired with the other compartment. During a subsequent free-choice test, a preference for the drug-paired compartment over the vehicle-paired compartment would be indicative of pleasant state induced by the drug. For all experiments, the conditioning session lasted 8 days and consisted of four pairings of the drug with one compartment and four pairings of the equivalent volume of vehicle with the other compartment. In experiment 1A, four groups of rats were designated according to the dose of propofol that they received intraperitoneally: 0,30,60, or 90 mg/kg. In experiment 1B, the same procedure was used with subanesthetic doses of intraperitoneal methohexital: 0,10,20, or 30 mg/kg. In experiment 2, the rats were conditioned during the recovery period from short-term anesthesia. For one group, anesthesia was induced by propofol (100 mg/kg) whereas for the other group, anesthesia was induced by an equivalent anesthetic dose of methohexital (40 mg/kg). RESULTS: In experiment 1A, the 30-mg/kg, 60-mg/kg, and 90-mg/kg groups showed a place preference for the drug-paired compartment, but only the group conditioned with 60 mg/kg propofol significantly differed from the 0-mg/kg group. In experiment 1B, the groups conditioned with methohexital showed no place preference for the drug-paired compartment. In experiment 2, the rats showed a place preference for the compartment in which they recovered from propofol-induced anesthesia but no place preference for the compartment in which they recovered from methohexital-induced anesthesia. CONCLUSIONS: Propofol, but not methohexital, induced a pleasant affective state in rats at subanesthetic doses as well as during recovery from an anesthetic dose.

Affect↗
PubMed1994

[Antibiotic prophylaxis and appendectomy].

Analysis of clinical studies shows that a single preoperative systematic administration of antibiotics may reduce postoperative sepsis rate after appendicectomy. If the appendix is gangrenous or perforated, this therapy must last for a longer time and is not considered as a prophylaxis. In clinical practice, there are obvious advantages in the use of a single agent efficient against both aerobes and anaerobes. According to the literature, cefotetan or cefoxitin (2 g in adults, 40 mg.kg-1 in children) can be proposed.

Anti-Bacterial Agents↗
PubMed1993

[Information to relatives of organ donors. Factors of consent or refusal. Results of a multicenter study].

The French law on organ harvesting in brain dead patients allows this to be done without the family's consent, but prescribes to inform the relatives. Despite this, most teams do not harvest organs if the family is strongly opposed to the procedure. Information given to the relatives is therefore a very important point in the management of the donor. This prospective multicentre enquiry was designed to assess the conditions in which relatives were informed, and to determine the criteria which improve the rate of consent for the donation. After such information had been given, a questionnaire was filled in and sent to France-Transplant. Two hundred and seven interviews were analysed over an 18-month period. In two thirds of cases, the relatives were interviewed less than three hours after the diagnosis of brain death had been made. A written information sheet was used in only one third of interviews. Information was given by telephone in 11% of cases. Organ donation was accepted, on average, in 74% of cases. This ratio, which did not depend on the hospital, increased with the age of the donor: 66% for donors aged less than 18 years to 86% for those more than 50 years old. The aetiology of brain death was not a factor determining acceptance of the donation. The main factor was the conditions of interview: acceptance rate was the highest when there was a one hour delay between giving the information on the donor's brain death and that concerning organ donation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Role of cyclic AMP in the prejunctional alpha 2-adrenoceptor modulation of noradrenaline release from the rat tail artery.

Experiments were designed to evaluate the effect of cyclic AMP on the electrically-induced release of noradrenaline from vascular sympathetic nerve terminals. The possible implication of the inhibition of adenylate cyclase in the negative feed-back control by prejunctional alpha 2-adrenoceptors of neurotransmitter release was also investigated. Rat isolated tail arteries were preincubated with [3H]-noradrenaline; the preparations were subsequently perfused/superfused with [3H )-noradrenaline-free medium and their perivascular nerves were field stimulated with 24 pulses at 0.4 Hz (0.3 ms, 200 mA). 2 compounds known to enhance the intracellular concentration of cyclic AMP, namely the membrane permeant analogue 8-Br-cAMP (10-300 mumol/l) and forskolin (0.3-10 mumol/l), an activator of adenylate cyclase, concentration-dependently enhanced the stimulation-evoked tritium overflow. The 1,9-dideoxy derivative of forskolin, which does not stimulate adenylate cyclase, was ineffective. Exposure to the cyclic AMP phosphodiesterase inhibitor rolipram 30 mumol/l produced a moderate increase (about 20%) in tritium overflow. However, in the presence of rolipram the facilitatory effect of forskolin was significantly more pronounced than in its absence. Whereas 8-Br-cAMP produced a slight concentration-dependent enhancement of the stimulation-induced vasoconstriction, forskolin and rolipram depressed it. The alpha 2-adrenoceptor agonist B-HT 933 (3-30 mumol/l) concentration-dependently inhibited the tritium overflow. The effect of B-HT 933 30 mumol/l was slightly, but significantly reduced in the presence of 8-Br-cAMP 100 and 300 mumol/l, but was not changed in the presence of forskolin 3 mumol/l. The facilitatory effect of rauwolscine 1 mumol/l was enhanced in the presence of 8-Br-cAMP 100 mumol/l. During perfusion with 8-Br-cAMP 100 mumol/l, the current strength and frequency were decreased to 150 mA and 0.2 Hz, respectively in order to obtain similar amounts of tritium overflow to those observed in the absence of the cyclic AMP analogue with the initial stimulation parameters. Under these conditions, the inhibition of the overflow by B-HT 933 30 mumol/l and the facilitation by the alpha 2-adrenoceptor antagonist rauwolscine 1 mumol/l were unaltered as compared to controls under initial stimulation conditions. It is concluded that, in the rat tail artery, the terminals of perivascular sympathetic nerves are endowed with an adenylate cyclase system. Cyclic AMP is able to modulate noradrenaline release, but does not appear to play a role in the initiation of the release process itself. In addition, the results do not support the hypothesis that prejunctional alpha 2-adrenoceptors depress noradrenaline release through the inhibition of adenylate cyclase.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1990

[Long time hospitalization in pediatric surgical intensive care units].

If the great majority of children stay in intensive care unit only for few days, a small group of patients stay for a long period of time, varying from 3 months to five years or even more. The small group include two very different entities. On the one hand, newborns with a congenital malformation, often digestive e.a. with a short small intestine, need a long time parenteral nutrition. In such cases, the family disturbance, the opening of the unit to the parents, the awakening of the infant, his psychomotor and affective attainments are as many problems for the whole medical team. On the other hand, children severely injured in accidents, that occurred on public thoroughfares or in domestic house holds, most of the time are older than 3 years. These children may present important central neurologic sequelae, or other major sequelae (multiple trauma, burn injuries, hypoxic cervical spinal cord injury). Their education, activities, games, and family relations must be actively supported. Does the hospital structure, and particularly the intensive care unit, meet such requirements in very long time hospitalization?

Adolescent↗
PubMedDate not supplied

Fetal pulse oximetry during labor of 62 patients.

The objectives of the study were to assess the ability of a fetal pulse oximeter to measure the fetal oxygen saturation (SPO2) continuously during labor and to assess the correlation between readings of fetal pulse oximetry and cord blood gases at birth. The Nellcor N-400 Fetal Oximeter was used in 62 women prospectively. The mean SPO2 was unchanged at the different stages of normal labor. 53.3 +/- 9.1 to 50.1 +/- 11.8% (n = 50). The SPO2 recorded during the pushing phase of stage II (n = 40) was correlated significantly with umbilical cord arterial pH (r = 0.55; p = 0.0002), venous pH (r = 0.63; p = 0.0001), venous PCO2 (r = 0.47; p = 0.002) and venous PO2 (r = 0.39; p = 0.01). SPO2 was also correlated with scalp pH (r = 0.52; p < 0.05; n = 21). No side effects were noted. Fetal pulse oximetry could be useful to assess fetal oxygenation during labor and at birth.

Adult↗