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Biomedical subjects

N Guy

Publications and source records attributed to N Guy.

At least 19 recordsLinked to original sources
PubMed2006

[Symptomatic treatments in amyotrophic lateral sclerosis].

ALS is a progressive, fatal, degenerative motor neuron disease of unknown cause. Although advances in understanding pathophysiology of ALS have stimulated the development of new therapies, most of them remain few efficient or ineffective and the main management of ALS patient, to improve quality of life by alleviating symptoms, is symptomatic treatment. This article discusses the approaches now in use to manage some of the most common symptoms of ALS including the following: spasticity, cramps, pain, laryngospasm, pseudobulbar syndrome, salivation and drooling, sleep disorders and fatigue, constipation and trophic troubles.

Amyotrophic Lateral Sclerosis↗
PubMed2005

Nociceptive stimulation activates locus coeruleus neurones projecting to the somatosensory thalamus in the rat.

In the thalamus, noradrenergic output from the pontine nucleus locus coeruleus (LC) may actively shape the response properties of various sensory networks en route to the cortex. Little is known, however, about the involvement of ascending noradrenergic innervation of the somatosensory thalamus in the processing of nociceptive information. To address this question, we combined the study of Fos expression upon nociceptive tooth pulp stimulation in the anaesthetized rat, with the detection of retrogradely traced neurones from the somatosensory thalamus. Cell bodies labelled retrogradely from the left thalamus were observed on both sides of the LC, with an ipsilateral predominance (n = 8). Electrical stimulation of the right incisor pulp (n = 4) provoked a significantly stronger Fos expression (around twice) than sham surgery (n = 4), in both the ipsi- and contralateral LC. Significantly larger numbers of double labelled neurones were counted in the LC of tooth-pulp-stimulated animals (representing around 30% of retrogradely labelled cells in LC) than in the LC of sham animals. They were found bilaterally, but with a clear, significant, ipsilateral (i.e. left) predominance. The present data offer an anatomical framework to understand how the LC is involved in the sensory processing of nociceptive information in the thalamus. For the first time, it is shown that nociceptive stimulation activates LC neurones projecting to the somatosensory thalamus. This suggests a new role for LC in modulating nociception within the thalamus.

Action Potentials↗
PubMed2004

TREK-1, a K+ channel involved in neuroprotection and general anesthesia.

TREK-1 is a two-pore-domain background potassium channel expressed throughout the central nervous system. It is opened by polyunsaturated fatty acids and lysophospholipids. It is inhibited by neurotransmitters that produce an increase in intracellular cAMP and by those that activate the Gq protein pathway. TREK-1 is also activated by volatile anesthetics and has been suggested to be an important target in the action of these drugs. Using mice with a disrupted TREK-1 gene, we now show that TREK-1 has an important role in neuroprotection against epilepsy and brain and spinal chord ischemia. Trek1-/- mice display an increased sensitivity to ischemia and epilepsy. Neuroprotection by polyunsaturated fatty acids, which is impressive in Trek1+/+ mice, disappears in Trek1-/- mice indicating a central role of TREK-1 in this process. Trek1-/- mice are also resistant to anesthesia by volatile anesthetics. TREK-1 emerges as a potential innovative target for developing new therapeutic agents for neurology and anesthesiology.

Anesthesia, General↗
PubMed2004

Risk factors for the development of extended-spectrum beta-lactamase-producing bacteria in nonhospitalized patients.

Although the risk factors for acquiring infection by extended-spectrum beta-lactamase (ESBL)-producing bacteria have been investigated in hospitalized patients, such risk factors have not been defined in the community setting. In this study, clinical data from a total of 311 nonhospitalized patients with community-acquired urinary tract infection (128 with ESBL-positive strains and 183 with ESBL-negative strains) were obtained. According to a multivariate analysis, the following were identified as independent risk factors: previous hospitalization in the past 3 months (OR=8.95, 95%CI, 3.77-21.25), antibiotic treatment in the past 3 months (OR=3.23, 95%CI, 1.76-5.91), age over 60 years (OR=2.65, 95%CI, 1.45-4.83), diabetes (OR=2.57, 95%CI, 1.20-5.51), male gender (OR=2.47, 95%CI, 1.22-5.01), Klebsiella pneumoniae infection (OR=2.31, 95%CI, 1.17-4.54), previous use of third-generation cephalosporins (P=0.014, OR=15.8, 95%CI, 1.7-143), previous use of second-generation cephalosporins (P<0.0001, OR=10.1, 95%CI, 4.2-24), previous use of quinolones (P=0.001, OR=4.1, 95%CI, 1.8-9.0), and previous use of penicillin (P=0.003, OR=4.0, 95%CI, 1.6-9.0).

Adolescent↗
PubMed2001

Spontaneous internal carotid artery dissection with lower cranial nerve palsy.

BACKGROUND: Typical presentation of spontaneous internal carotid artery (ICA) dissection is an ipsilateral pain in neck and face with Horner's syndrome and contralateral deficits. Although rare, lower cranial nerve palsy have been reported in association with an ipsilateral spontaneous ICA dissection. CASE STUDIES: We report three new cases of ICA dissection with lower cranial nerve palsies. RESULTS: The first symtom to appear was headache in all three patients. Examination disclosed a Horner's syndrome in two cases (1 and 2), an isolated XIIth nerve palsy in two patients (case 1 and 3) and IX, X, and XIIth nerve palsies (case 2) revealing an ipsilateral carotid dissection, confirmed by MRI and angiography. In all cases, prognosis was good after a few weeks. CONCLUSIONS: These cases, analysed with those in the literature, led us to discuss two possible mechanisms: direct compression of cranial nerves by a subadventitial haematoma in the parapharyngeal space or ischemic palsy by compression of the ascending pharyngeal artery.

Anticoagulants↗
PubMed1999

The effect of long-term antipsychotic treatment on the body weight of patients suffering from chronic schizophrenia: clozapine versus classical antipsychotic agents.

The aim of this study was to evaluate the effect of long-term clozapine treatment on body weight changes in neuroleptic-resistant chronic schizophrenic patients and to compare it with that of classical antipsychotic agents. The body mass index (BMI) of 96 neuroleptic-resistant chronic schizophrenic patients was calculated before the beginning and after long-term (mean +/- SD 1.7 +/- 1.3 years) clozapine treatment. These data were compared to the BMI of 98 chronic schizophrenic patients maintained on classical antipsychotic agents for a similar duration (mean +/- SD 1.9 +/- 1.6 years). A significant elevation in BMI was detected in both groups during these periods (P < 0.0001 versus baseline, for both groups). The change in BMI (delta BMI) was similar in both groups (P < 0.9). We conclude that the increase in body weight caused by long-term (> 6 months) clozapine treatment is comparable to that obtained following long-term classical antipsychotic agents treatment.

Adult↗
PubMed1999

Clomipramine-induced urinary retention in a cat.

A 10-year-old, female, spayed shorthair with presumed psychogenic alopecia was treated with clomipramine (1 mg/kg body weight/day). The cat developed urinary retention within 2 days. Clomipramine was discontinued. Clinical signs resolved over the next 7 days. The urinary retention was attributed to the anticholinergic effects of clomipramine.

Alopecia↗
PubMed1995

[Clozapine for resistant schizophrenia and characteristics of those responding].

Clozapine (Leponex) is an atypical antipsychotic drug which is effective in the treatment of resistant schizophrenia. The most severe side-effect is agranulocytosis, which occurs in 12%. 50 patients with resistant schizophrenia were screened retrospectively in order to characterize features which might help predict good response to the drug. The drug was more effective in young patients with recent onset of illness and short total duration of hospitalization.

Adolescent↗
PubMed1995

Brain chimeras for the study of an avian model of genetic epilepsy: structures involved in sound and light-induced seizures.

The epileptic homozygotes of the Fayoumi strain of chickens (Fepi) are affected by photogenic reflex epilepsy with complete penetrance. Here we demonstrate that they are equally affected by audiogenic reflex epilepsy induced by intense sound stimulation. All the Fepi display sound-induced seizures from hatching to adulthood consisting of initial 'ictal arousal' and running fits usually followed by generalized clonico-tonic convulsions. A running fit is the preconvulsive motor symptom specifically induced by auditory stimulation while neck myoclonus is the preconvulsive motor symptom specifically induced by photic stimulation. The EEG interictal spikes and spike and waves are suppressed and replaced by a desynchronized trace during the seizures of both kinds. Viable neural chimeras were obtained by graft of embryonic brain vesicles from Fepi donors into normal chick embryos. Transfer of the complete audiogenic and photogenic phenotypes was obtained in chimeras resulting from embryonic substitution of both the prosencephalon and mesencephalon. The substitution of the prosencephalon alone resulted in transfer of interictal paroxysmal EEG activity accompanied by the sound and light-induced desynchronization and 'ictal arousal' with no motor seizures. Chimeras with embryonic substitution of the mesencephalon alone displayed running fits and convulsions induced by sound stimulation but only neck myoclonus following light stimulation. The conclusions are reached that: (i) the Fepi is a model of audiogenic and photogenic reflex epilepsy; (ii) in both types, the seizure initiator and the convulsion generator are localized in the brainstem, although reinforcement from telencephalic visual structures is needed to trigger photogenic generalized convulsions.

Acoustic Stimulation↗
PubMed1994

[Retrograde ejaculation as a side-effect of clozapine].

3 chronic paranoid schizophrenic men, aged 29, 30 and 37 years, respectively, developed retrograde ejaculation, a rare side-effect of clozapine. It disappeared after the dose was lowered in 1 of the patients and after stopping the drug in the other 2. On rechallenging with the drug, retrograde ejaculation recurred.

Adult↗
PubMed1994

[A case of self-circumcision].

A 29-year-old bachelor had immigrated from Uzbekistan to Israel 2 years before to improve his economic situation. He began drinking at the age of 20, and increased to 1-1.5 bottles of vodka a day. He was unable to keep a job more than a few months. When called up for limited military service, he thought that the army might be a solution for his employment problem. However, he felt that he would not be able to integrate into the army, and later into Israeli society, unless he was circumcised. The Ministry of Religion deferred his request for a religious circumcision because they did not consider him Jewish. Since he could not afford to pay for the operation, he read up on the procedure, drank a bottle of vodka as premedication, and tried to circumcise himself with a razor blade. Since he was unable to control bleeding, he applied to the hospital emergency room half an hour later, where the circumcision was completed and sutured. The psychiatric diagnosis was an unspecified personality disorder with psychopathic but not psychotic features.

Adult↗
PubMed1994

[Mediagenic psychoses].

Disturbances of psychotic intensity resulting from external trauma at times of crisis and tension have been described in the literature, particularly in combat reactions, including the Saddam syndrome. Acute psychoses as reactions to mystical-religious fervor have also been described. We describe 2 clusters of patients admitted with an acute, delusional, psychotic picture against the background of the Vanunu treason trial and later the strong messianic expectations aroused among the followers of the Rebbe of Lubavitch. Both of these events received extensive coverage in the Israeli press and electronic telecommunication media. The emergence of the mental disturbances and the content of the psychoses were linked to the particularly strident and dramatic media coverage of these 2 events. The impact of the reports of wide-spread messianic fantasies in the contemporary news bulletins on those with preexisting premorbid sensitivity was sufficient to trigger the psychoses. The delusional content was topical, and not that of the traditional psychotic delusions such as that of being Napoleon. This emphasizes that not only an authentic major external trauma such as a war is capable of triggering psychosis, but also emotionladen, stressful news items, frequently repeated in the media (such as reports of espionage or messianic fervor), may have similar effects.

Acute Disease↗
PubMed1993

[Transfer of photosensitive epilepsy of genetic origin by selective grafts of brain vesicles in chick embryo].

We transferred the avian photosensitive genetic epilepsy to normal chicken by transplanting at least prosencephalic and mesencephalic vesicles from epileptic to normal chick embryos at day 2 of incubation. Chimeras showed typical interictal EEG and developed, under intermittent light stimulation, seizures phenotypically and electrically similar to the epileptic strain seizures.

Animals↗
PubMed1992

Pattern of electroencephalographic activity during light induced seizures in genetic epileptic chicken and brain chimeras.

Genetic epilepsy was studied in Fayoumi epileptic (F.Epi) chickens and in neural chimeras obtained by selective substitution of embryonic brain vesicles of F.Epi donors in normal recipient chickens. Typical motor seizures accompanied by convulsions were evoked by intermittent light stimulation in F.Epi and in chimeras having embryonic substitution of the prosencephalon and the mesencephalon. The motor seizure was less severe in chimeras receiving only the prosencephalon. In the F.Epi, as well as in all the chimeras, the EEG during seizures was characterized by a desynchronized (or a flattening) pattern of activity. F.Epi and chimeras had a lower threshold to Metrazol induced seizures than control chickens. The experimental animals show that, in this model, large prosencephalic and mesencephalic areas are involved in the epileptic disease. The epileptic character of this genetic dysfunction is discussed.

Animals↗
PubMed1992

Superoxide production during refeeding in patients with anorexia nervosa.

The effect of undernutrition and refeeding on superoxide production by polymorphonuclear cells (PMN) was studied in 11 girls suffering from anorexia nervosa (AN) and 17 age-matched, normal, healthy, control subjects. Superoxide anion production by PMNs from undernourished AN patients was comparable to normal, while a significant decrease in this function was observed during the initial period of refeeding. After a more extended period of refeeding, superoxide production by PMNs from AN patients increased and gradually returned toward normal values. Superoxide production correlated with length of the refeeding period (RF), weight as a percentage of ideal weight for height (W/H%), and rate of weight gain (WG). These results imply that a variety of physiological parameters, including susceptibility to infection, may be altered by refeeding undernourished patients.

Adolescent↗
PubMed1992

["Saddam syndrome:" acute psychotic reactions during the Gulf War--renewal of concept of brief reactive psychosis].

6 patients came to our psychiatric emergency room during the first 2 weeks of the Gulf War presenting the clinical picture of acute delusional paranoid psychosis (4 women and 2 men between the ages of 30-77). 4 were without previously known psychopathology, while the other 2 were known to have had some nonpsychotic cognitive impairment. The first 4 recovered completely within a short time while the other 2 continued to have psychopathological symptoms. We discuss psychogenic or reactive psychosis, and the concept of reactivation when cumulative trauma exceed the individual's personal threshold, as may occur during a war. Different phenomenological syndromes may follow.

Acute Disease↗
PubMed1992

[Combined tricyclic antidepressants and ritalin in elderly depressives].

Psychostimulants, including ritalin (methylphenidate), were used as antidepressives in the '50s but were then replaced by tricyclics and MAO inhibitors. Treatment of depression with psychostimulants is still controversial. Several anecdotal reports in the past decade approved the use of tricyclic antidepressants (TCA) together with methylphenidate in apathetic and withdrawal states in medically ill and in elderly patients. Ritalin elevates mood by releasing catecholamines and blocking their re-uptake, and also increases serum TCA levels. 5 men and 5 women between the ages of 65 and 79 were diagnosed as suffering from major depressive disorders, either single or recurrent, based on the Revised Diagnostic and Statistical Manual for Mental Disorders (DSM-III-R). They had been treated with TCA for up to several months with no response. Following addition of methylphenidate, 5-15 mg/d for 2 weeks, 4 men and 3 women improved rapidly, 2 of them within 24 hours.

Aged↗