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Biomedical subjects

M Poncet

Publications and source records attributed to M Poncet.

At least 19 recordsLinked to original sources
PubMed2000

[Chief health risks associated with intravenous heroin and cocaine abuse].

THREE CATEGORIES OF COMPLICATIONS: Heroine and cocaine are the main drugs used by injecting drug-users (IDU) in France. There are three categories of complications associated with intravenous drug abuse: effects related to drug toxicity, effects associated with the administration route, and effects associated with social implications of drug-dependence. OTHER HEALTH PROBLEMS: The impact of HIV infection among IDU, particularly in southern Europe, has led to renewed interest in the other health problems raised by this population. A review of recent literature shows that cocaine toxicity is better understood than heroine toxicity. In addition, intravenous drug abuse can lead to a whole series of disease states related to trauma or infection.

Cocaine↗
PubMed2000

Multicenter prospective study of children with sickle cell disease: radiographic and psychometric correlation.

After obtaining familial informed consent, between January 1996 and July 1997, 173 children (5 to 15 years old) with sickle cell disease were enrolled in a prospective multicenter study using blood screening, transcranial Doppler ultrasonography (n = 143), cerebral magnetic resonance imaging (n = 144), and neuropsychologic performance evaluation (n = 156) (Wechsler Intelligence tests WISC-III, WIPPSI-R), which were also performed in 76 sibling controls (5 to 15 years old). Among the 173 patients with sickle cell disease (155 homozygous for hemoglobin SS, 8 sickle cell beta0 thalassemia, 3 sickle cell beta+ thalassemia, 7 sickle cell hemoglobin C disease SC), 12 (6.9%) had a history of overt stroke, and the incidence of abnormal transcranial Doppler ultrasonography (defined as mean middle cerebral artery velocity > 200 cm/sec or absent) was 8.4% in the overall study population and 9.6% in patients with homozygous sickle cell anemia The silent stroke rate was 15%. Significantly impaired cognitive functioning was observed in sickle cell disease patients with a history of stroke (Performance IQ and Full Scale IQ), but also in patients with silent strokes (Similarities, Vocabulary, and Verbal Comprehension). However, infarcts on magnetic resonance imaging were not the only factors of cognitive deficit: Verbal IQ, Performance IQ, and Full Scale IQ were strongly impaired in patients with severe chronic anemia (hematocrit < or = 20%) and in those with thrombocytosis (platelets > 500 x 10(9)/L). Multivariate logistic regression analysis showed that abnormal magnetic resonance imaging (odds ratio [OR] = 2.76) (P = .047), hematocrit < or =20% (OR = 5.85) (P = .005), and platelets > 500 x 10(9)/L (OR = 3.99) (P = .004) were independent factors of cognitive deficiency (Full Scale IQ < 75) in sickle cell disease patients. The unfavorable effect of low hematocrit has already been suggested, but this is the first report concerning an effect of thrombocytosis and showing that silent stroke alone is not a factor of cognitive deficit when not associated with low hematocrit or thrombocytosis. The effect of hydroxyurea, which is known to increase hematocrit and decrease platelet count, on cognitive functioning of sickle cell patients should be evaluated prospectively.

Adolescent↗
PubMed1999

Category specificity in object agnosia: preservation of sensorimotor experiences related to objects.

We report a case of semantic agnosia, characterized by category specificity. Object recognition, mainly involving visual representation, was severely impaired, whereas object recognition involving both visual and sensorimotor representations, was relatively well preserved. His ability to recognize gestures and produce appropriate gestural responses to objects was remarkable. These two factors lead the authors to form a hypothesis, in an attempt to explain the mechanisms involved in object recognition. It has been argued that manipulation of an object may give access to a certain amount of knowledge about it, and that preservation of sensorimotor experiences of objects might be important in recognizing some of them. This could account for the category specificity, described in object agnosia.

Agnosia↗
PubMed1999

A 24-month, double-blind, placebo-controlled multicentre pilot study of the efficacy and safety of nicergoline 60 mg per day in elderly hypertensive patients with leukoaraiosis.

In this pilot study, 72 non-demented and non-depressive elderly hypertensive patients with evidence of leukoaraiosis on cerebral computed tomography scan (Rezek score: > 16) were randomly assigned to receive either nicergoline 30 mg b.i.d. (n = 36) or a placebo (n = 36) for 24 months. All patients received antihypertensives and their hypertension was controlled under treatment. They were evaluated by nine neuropsychological tests exploring memory, concentration, verbal and motor performances, administered at baseline and at every six-month interval during the study period. At baseline, the two groups were comparable for all demographic and clinical characteristics, including cognitive functions, except for the delayed recall of the Auditory Verbal Learning Test (AVLT), which was better in the placebo group (P = 0.04). Changes in scores over time were compared between the two groups. At the last visit, patients on nicergoline (n = 31) were found to have deteriorated less or to have improved more on test scores than the patients on placebo (n = 30). Significant differences were observed for memory function (AVLT short term recall, P = 0.026; AVLT delayed recall, P = 0.013; and, Benton Visual Retention Test, P = 0.002) and attention and concentration (Letter Cancellation Test, P = 0.043; and, WAIS-R Digit Symbol subtest, P = 0.006). The Rezek score remained unchanged in the two groups. Tolerance of nicergoline was similar to that of placebo. In conclusion, this study shows that nicergoline 30 mg b.i. d. administered over a 24-month period attenuates the deterioration in cognitive functions in elderly hypertensive patients with leukoaraiosis. Whether these effects were specific for this type of white matter changes could not be determined in the context of this pilot study.

Aged↗
PubMed1999

[Progressive focal cortical atrophies].

Progressive focal cortical atrophies are degenerative conditions characterised by the insidious onset and gradual exacerbation of an impairment in a single cognitive domain related to circumscribed cerebral atrophy. Several focal cortical syndromes with deficits in the realm of cognition are reviewed: progressive impairment of language (primary progressive aphasia), speech (progressive anarthria), semantic memory (semantic dementia), episodic memory (pure progressive amnesia), vision (progressive perceptual or visuo-spatial deficits) and gesture (progressive apraxia). These conditions are histologically heterogeneous and can be associated with focal non-specific neuronal loss and gliosis with some spongiform changes (non-specific lesions), pathological features of Pick's disease (inclusion bodies and swollen neurones) or Alzheimer's disease (AD) (senile plaques and neurofibrillary tangles). A relationship between neuropsychological profiles and lesional types emerges from this review of the literature. Non-fluent primary progressive aphasia, semantic dementia and progressive anarthria are usually associated with non-specific lesions and Pick-type pathology. Progressive disorders of episodic memory and progressive visuo-spatial deficits are more often related to AD. If adequate clinical characterisation can determine the underlying disorder, it appears even more important to establish the neuropsychological profile in patients with cortical degenerative disease. Progressive deficits of only one domain of cognition may well be due to preferential involvement of anatomically and functionally defined neural systems and could therefore be considered as "system atrophies". There remains no doubt that these syndromes are particularly well suited models for studies on the relationship between cerebral functions and their neural substrate.

Aged↗
PubMed1998

A permanent pure amnestic syndrome of insidious onset related to Alzheimer's disease.

A 55-year-old patient experienced a pure amnestic syndrome of insidious onset that worsened progressively. Subsequently, her memory disorder stabilized and remained her only cognitive impairment for several years. She ultimately developed more widespread cognitive decline and terminal dementia. Postmortem examination 18 years after the onset revealed numerous senile plaques and neurofibrillary tangles consistent with Alzheimer's disease. A permanent pure amnestic syndrome of insidious onset may represent a further type of focal cerebral degeneration.

Alzheimer Disease↗
PubMed1998

Optic aphasia with pure alexia: a mild form of visual associative agnosia? A case study.

A single-case study is reported of a naming disorder selective to the visual modality. The patient showed intact access to structural knowledge of objects and letters, but impaired access to complete semantic knowledge of objects and alphabetical knowledge of letters from visual input. The impairment was most striking when the patient had to discriminate between semantically similar objects or within a given symbolic repertoire, i.e. letters. The co-occurrence of a partial deficit of visual recognition for objects and for letters indicated features of optic aphasia and pure alexia. This symmetric performance between object and letter processing may also constitute a mild form of visual associative agnosia.

Aged↗
PubMed1998

Adapalene 0.1% gel and adapalene 0.1% cream stimulate retinoic acid receptor mediated gene transcription without significant irritative effects in the skin of healthy human volunteers.

A randomized, investigator masked, intra individual comparative study was conducted in 30 healthy volunteers to compare the cutaneous effects of adapalene 0.1% gel and adapalene 0.1% cream with their respective vehicles, using tretinoin 0.05% cream (n = 21) or tretinoin 0.1% cream (n = 9) and a tretinoin cream vehicle (n = 30) as controls. The products were applied to hip/buttock skin for 4 days under occlusive conditions. Cytosolic retinoic acid binding protein-II (CRABP-II) mRNA levels were measured using the RT-PCR technique in punch biopsies taken from 10 subjects. Epidermal thickness was assessed using image analysis of haematoxylin and eosin stained sections from another 11 subjects. Erythema was assessed in all subjects both by a visual scoring system and by chromameter. Adapalene 0.1% gel and adapalene 0.1% cream produced similar significant increases in CRABP-II mRNA levels compared to their vehicles (P < 0.01). The two tretinoin formulations also resulted in similar significant increases in CRABP-II compared to the cream vehicle (P < 0.001). However, only the two tretinoin formulations resulted in an increase in epidermal thickness and only the tretinoin 0.1% cream resulted in significant erythema. Adapalene 0.1% gel and adapalene 0.1% cream induce RAR-mediated gene expression to a similar degree in this model, without the irritant effects of tretinoin.

Adapalene↗
PubMed1998

Evaluation of clinical efficacy and safety of adapalene 0.1% gel versus tretinoin 0.025% gel in the treatment of acne vulgaris, with particular reference to the onset of action and impact on quality of life.

A randomized, multicentre, investigator-masked study was conducted in 105 patients with mild to moderate acne vulgaris to compare the efficacy and safety of adapalene 0.1% gel with tretinoin 0.025% gel after three months of treatment, with particular emphasis on reduction in inflammatory lesion counts after one week of treatment and impact on quality of life. In terms of efficacy, adapalene gel was found to be superior to tretinoin gel after one week of treatment, with respect to reduction in inflammatory lesion counts (32% vs. 17%, respectively; P = 0.001), total lesion counts (28% vs. 22%, respectively; P = 0.042) and global severity grade (28% vs. 16%, respectively; P = 0.001). No significant difference between the two treatments was found after 12 weeks of treatment for any of these variables. Evaluation of facial skin tolerance parameters showed significant differences between the two treatments in favour of adapalene for dryness, erythema, immediate and persistent burning and pruritus for at least one time point. One patient in the adapalene group and three patients in the tretinoin group experienced medical events which lead to discontinuation of treatment (skin irritation; NS). Quality of life scores improved more rapidly in the adapalene group than in the tretinoin group, with significant differences (P < 0.05) appearing at week 1 for questions related to problems with partners, close friends or relatives and to skin symptoms. There was also a significantly greater improvement in social and leisure activity in the adapalene group at week 12. Adapalene 0.1% gel reduced inflammatory and total lesion counts more rapidly than tretinoin 0.025% gel, and was also better tolerated. These differences appear to result in an earlier and greater quality of life improvement for the patients receiving adapalene.

Acne Vulgaris↗
PubMed1998

A comparison of the efficacy and tolerability of adapalene 0.1% gel versus tretinoin 0.025% gel in patients with acne vulgaris: a meta-analysis of five randomized trials.

The purpose of this meta-analysis was to determine if adapalene 0.1% gel (Differin) provided superior efficacy and better tolerability than tretinoin 0.025% gel in the treatment of acne vulgaris. All comparative studies, both published and unpublished, from the United States and Europe, that fulfilled rigorous protocol criteria (multicentre, randomized, investigator-blind) were used. Five comparative studies met these criteria. In total, the meta-analysis evaluated 900 patients (450 treated with adapalene 0.1% gel, 450 treated with tretinoin 0.025% gel) with mild-to-moderate acne from the combined clinical trials. To avoid study bias, the meta-analysis used an intention-to-treat analysis. Statistical methodology for the meta-analysis included analysis of covariance, analysis of variance and Cochran-Mantel-Haenszel test. All statistical tests were two-sided, with the 0.05 probability level used to establish statistical significance, and 95% confidence intervals used to assess equivalence. Adapalene demonstrated equivalent efficacy to tretinoin in terms of reducing total lesion count. Adapalene demonstrated more rapid efficacy, as evidenced by a significant difference in the reduction of inflammatory and total lesions at week 1. Adapalene also demonstrated considerably greater local tolerability at all evaluation periods. The findings from this meta-analysis suggest that adapalene 0.1% gel constitutes a pharmacologic advance over such classic retinoids as tretinoin for the treatment of acne vulgaris.

Acne Vulgaris↗
PubMed1998

Separate visual pathways for perception of actions and objects: evidence from a case of apperceptive agnosia.

Recognition of different kinds of visual stimuli was studied in a patient who acquired apperceptive visual agnosia after a bilateral occipitotemporal lesion which partially spared the primary visual cortex. Impairment in recognising static objects perceived visually sharply contrasts with the relatively well preserved ability to recognise objects from gestures illustrating their use, and to recognise actions shown in line drawings. It is suggested that the occipitoparieto-frontal pathway is involved in the recognition of actions, and in the recognition of objects when sensorimotor experience is evoked.

Aged↗
PubMed1998

Progressive loss of speech: a neuropsychological profile of premotor dysfunction.

Several patients with 'progressive loss of speech output' or 'progressive anarthria' of degenerative origin have been reported in the literature. We report 5 clinical cases with slowly progressive loss of speech output and initially no deficit in other cognitive domains. The early clinical features were analysed in an attempt to identify the anatomo-functional systems implied in the degenerative process. The first phase of the disorder was characterised by impaired articulation consistent with speech apraxia, telegraphic style and a difficulty to elaborate a series of orofacial or hand movements. It is argued that these symptoms result from an impairment of complex motor processing due to dysfunction of the ventral premotor system. In the second phase, a decrease in spontaneous speech and self-initiated action was combined with exaggerated dependency on external stimuli, interpreted as dysfunction of the dorsal premotor system. We suggest that the neuropsychological profile of the disorder may result from progressive degeneration of the premotor cortex.

Aged↗
PubMed1998

[Diagnostic dyspraxia and frontal syndrome].

A 27-year-old ambidexter woman experienced a clinical and psychometric frontal syndrome associated with a partial callosal syndrome following transcallosal surgery for an intraventricular neurocytoma. She also complained of difficulties with her left hand which realized a particular form of diagnostic dyspraxia: there were specific features of an isolated dysfunction of the control of the realization of a program.

Adult↗
PubMed1997

Category-specific anomia: implication of different neural networks in naming.

The occurrence of anomia specifically affecting the ability to name animals is described in three patients. This deficit is contrasted with their capacity to name actions and tools. It is suggested that it is easier to access the names of 'operative' items, which were learned through both visual and sensorimotor experience, than the names of 'figurative' items, which were primarily learned through the visual modality. This hypothesis is consistent with the infero-temporal location of brain damage in these patients. Their ability to retrieve knowledge about operative items is assumed to be due to the sparing of the occipito-parietal area. Because the impairment also involves the recognition of animals, the likely locus of damage is the semantic component of the processing system.

Aged↗
PubMed1997

Three-dimensional MRI of hemifacial spasm with surgical correlation.

MRI was used to investigate 100 patients with hemifacial spasm, using 3D-FT T2-weighted (CISS) and contrast-enhanced 3D-FT T1-weighted (turbo-FLASH) sequences in all cases. MR angiography was performed in 54 patients, using 3D-MT FISP images. Decompression of the facial nerve through a retromastoid craniotomy was performed in all patients. Hemifacial spasm caused by tumours in the cerebellopontine angle was not included. Vascular contact with the facial nerve root-exit zone or at the internal auditory canal was present in 96 of 100 patients with hemifacial spasm. The vessel responsible was the vertebral artery (VA) in 18 cases, the posterior inferior cerebellar artery (PICA) in 23, the anterior inferior cerebellar artery (AICA) in 22, the VA and PICA in 24, VA and AICA in 3, PICA and AICA in 1, VA, PICA and AICA in 4, and a vein in 1 case. CISS images showed compressive vascular loops better than contrast-enhanced turbo-FLASH images alone. The sensitivity of MRI was high, since only one false-negative case was found among the 100 patients who underwent surgery.

Adult↗
PubMed1997

Optic aphasia: evidence of the contribution of different neural systems to object and action naming.

Visual stimulus naming was studied in a 66-year-old male patient with optic aphasia subsequent to left occipito-temporal infarction. While having difficulty in naming objects perceived visually, he was able to name objects by viewing gestures illustrating their use, and to name actions shown in pictures. These results suggest that naming performance depends on the kind of stimulus that is visually presented (object vs. action). The present findings lend support to congnitive models which postulate the existence of visual and functional semantic systems.

Aged↗
PubMed1997

Adapalene 0.1% gel has low skin-irritation potential.

BACKGROUND: Adapalene is a new naphthoic acid derivative with potent retinoid and antiinflammatory properties, developed for the topical treatment of acne vulgaris. OBJECTIVE: We compare the cutaneous safety of adapalene in different gel vehicles with tretinoin 0.025% gel. METHODS: A total of 42 healthy human subjects were enrolled in two randomized, double-blind, controlled, intraindividual studies. In the first study (study A), adapalene aqueous 0.03% and 0.1% gels were evaluated for their 21-day cumulative irritation potential compared with vehicle alone, patch alone, and tretinoin 0.025% gel under occlusion. In the second study (study B), adapalene aqueous (0.03% and 0.1%) gels and adapalene alcoholic (0.03% and 0.1%) gels were evaluated for their 5-day cumulative irritation potential compared with their respective vehicles and tretinoin 0.025% gel. Transepidermal water loss (TEWL) was measured daily at each visit. RESULTS: In study A, adapalene had a slight irritation potential that was in the same range as the gel vehicle and the patch alone, whereas tretinoin 0.025% gel was a severe irritant. In study B, no irritation was seen with either adapalene aqueous gels or adapalene gel vehicles or patch alone. The adapalene alcoholic gels were slightly irritating, and tretinoin gel produced intense irritation reactions in the majority of subjects. TEWL increased fourfold at the tretinoin site but remained unchanged at all adapalene sites. CONCLUSION: Adapalene 0.1% gel was significantly less irritating than tretinoin 0.025% gel.

Adapalene↗