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Biomedical subjects

J Pelletier

Publications and source records attributed to J Pelletier.

At least 19 recordsLinked to original sources
PubMed2005

Idiopathic acute transverse myelitis: application of the recent diagnostic criteria.

Despite an extensive diagnostic workup, some cases of acute transverse myelitis (ATM) remain of unknown etiology and have been referred to as "idiopathic" by the Transverse Myelitis Consortium group. In a retrospective study of 288 patients with ATM, 45 cases (15.6%) met the criteria for idiopathic ATM. The patients formed a relatively homogeneous group in terms of clinical and MRI data, but the prognosis was highly variable.

Adrenal Cortex Hormones↗
PubMed2005

A new aldehyde oxidase selectively expressed in chemosensory organs of insects.

Signal termination is a crucial step in the dynamic of the olfactory process. It involves different classes of odorant-degrading enzymes. Whereas aldehyde oxidase enzymatic activities have been demonstrated in insect antennae by previous biochemical studies, the corresponding enzymes have never been characterized at the molecular level. In the cabbage armyworm Mamestra brassicae, we isolated for the first time an aldehyde oxidase partial cDNA specifically expressed in chemosensory organs, with the strongest expression in antennae of both sexes. In these organs, expression was restricted to the olfactory sensilla. Our results suggest that the corresponding enzyme could degrade aldehyde odorant compounds, such as pheromones or plant's volatiles.

Aldehyde Oxidase↗
PubMed2005

Modafinil for fatigue in MS: a randomized placebo-controlled double-blind study.

OBJECTIVE: To assess whether modafinil, a wakefulness-promoting agent, is useful for fatigue in patients with multiple sclerosis (MS). METHODS: Patients with MS with stable disability, and a baseline score of 45 or more on the Modified Fatigue Impact Scale (MFIS), were eligible for the 5-week randomized, double-blind, placebo-controlled, parallel group study. The initial daily dose of modafinil was 200 mg for 1 week. Depending on tolerance, the dose was increased by 100 mg every week up to 400 mg/day and remained unchanged between day 21 and day 35. The primary outcome variable was the change of MFIS score at day 35. RESULTS: A total of 115 patients with MS were enrolled in the study and in the intention to treat analysis. The mean MFIS score at baseline was 63 +/- 9 in the placebo group and 63 +/- 10 in the modafinil group. MFIS scores improved between day 0 and day 35 in both placebo-treated and modafinil-treated groups, but no significant difference was detected between the two groups. There was no major safety concern. CONCLUSIONS: There was no improvement of fatigue in patients with multiple sclerosis treated with modafinil vs placebo according to the Modified Fatigue Impact Scale.

Adult↗
PubMed2005

Functional MRI study of PASAT in normal subjects.

The paced auditory serial addition test (PASAT) is routinely used to evaluate the cognitive part of the multiple sclerosis functional composite (MSFC) score, the new reference index of patient disability. PASAT is sensitive to subtle cognitive impairment related to MS, although the cognitive components of this test still remain unclear. In order to better characterize brain systems involved during this complex task, functional magnetic resonance imaging (fMRI) experiments were conducted during PASAT in a population of ten normal subjects. The paradigm consisted of a series of 61 single-digit numbers delivered every 3 s. After each number, subjects were asked to overt vocalize the result of the addition of the two last numbers heard. A control task consisting of the repetition of the same series of single-digit numbers was used. Statistical group analysis was performed using the random effect procedure (SPM 99). Cortical activation was observed in the left prefrontal cortex, the supplementary motor area, the lateral premotor cortex, the cingulate gyrus, the left parietal lobe, the left superior temporal gyrus, the left temporal pole, and visual associative areas. fMRI activations underlying PASAT were consistent with an involvement of verbal working memory and the semantic memory retrieval network which could be related to arithmetic fact retrieval. This study on normal subjects could provide a base for the understanding of the potential abnormal cortical activation in MS patients performing this test for a cognitive evaluation.

Adult↗
PubMed2005

[Multiple strokes after chickenpox primo-infection in an adult].

INTRODUCTION: Chickenpox is considered as a high risk factor for developing stroke in childhood, but descriptions in adult are exceptional (only three cases reported, to our knowledge). CASE REPORT: A 37-year-old man presented with a chickenpox eruption, followed by a right parietal and a left occipital infarcts, associated with multiple lacunae. There was no coagulation disorder, no hypertension or cardiovascular disorder. Cerebral angiography showed an irregular narrowing of the right internal parietal artery and vascular defects in right parietal and left occipital areas. The diagnosis of VZV-related vasculitis was evoked. White cell count, serology and VZV PCR were negative in the cerebrospinal fluid. Clinical improvement was observed after treatment by corticosteroids and aciclovir. CONCLUSION: Chickenpox is a rare cause of cerebral vasculitis. Involvement of both medium and small vessels was present here, contrary to other adult case reports in the literature. Hematogenous dissemination of the virus responsible for cerebral vasculitis seems to be the most probable pathophysiological mechanism.

Adult↗
PubMed2005

Randomized study of once-weekly interferon beta-1la therapy in relapsing multiple sclerosis: three-year data from the OWIMS study.

BACKGROUND: Once weekly interferon beta-1a for multiple sclerosis (OWIMS) demonstrated modest, but significant, magnetic resonance imaging (MRI) benefit of once-weekly (qw) interferon (IFN) beta-1a at 48 weeks, but no significant effect on relapses. OBJECTIVE: An OWIMS extension permitted assessment of longer-term efficacy/safety of qw IFN beta-1a in relapsing-remitting multiple sclerosis (RRMS). METHODS: Placebo patients were rerandomized to IFN beta-1a, 22 or 44 mcg qw, for two additional 48-week intervals. Primary outcome was MRI lesion activity. Relapse rate and other MRI measures were secondary outcomes. RESULTS: After three years, median (mean) T2 lesion count/patient/scan was 1.3 (2.6) for 44 mcg, 1.7 (3.3) for 22 mcg, 1.7 (3.4) for placebo/22 mcg, 2.0 (3.6) for placebo/44 mcg (all differences not significant). Annualized relapse rates were lowest for 44 mcg (0.77) versus other groups (0.83-0.86, not significant). Persistent neutralizing antibodies did not affect relapse rates, but MRI active lesions were increased in antibody-positive patients receiving 44 mcg compared to antibody negative patients. CONCLUSIONS: In RRMS, once weekly IFN beta-1a, particularly 44 mcg, can induce a significant MRI, but not relapse, effect, compared with placebo. No significant dose effect was seen. In contrast to the significant effect observed with three-times-weekly dosing of subcutaneous IFN beta-1a compared with placebo, this study confirms the lack of meaningful clinical benefit with once-weekly dosing.

Adjuvants, Immunologic↗
PubMed2004

Modulation of effective connectivity inside the working memory network in patients at the earliest stage of multiple sclerosis.

fMRI and structural equation modeling (SEM) were used to study effective connectivity inside the working memory network in patients at the earliest stage of multiple sclerosis (MS), while performing paced auditory serial addition test (PASAT), a sensitive task to reveal subtle cognitive impairments related to working memory and information speed processing. The path model used for SEM included bilateral connections between left and right BA 46, left and right BA 40, left and right anterior cingulate cortex (ACC), left BA 44 and left BA 40, right BA 44 and right BA 40, and unidirectional ipsilateral connections from BA 46 to BA 44, from ACC to BA 46, and from ACC to BA 44. Experimental data from the two groups fit accurately the working memory model, in patients [chi20(2) = 13, P = 0.877] as well as in controls [chi20(2) = 13.54, P = 0.853]. The omnibus test indicated a significant difference of model fits in patients and in controls [chi40(2) = 160.07, P < 0.0001]. Connectivity strengths from right BA 46 to left BA 46, from left ACC to left BA 46 were lower in patients than in controls, and higher from right ACC to right BA 46, from left to right and from right to left ACC (stacked model). Effective connectivity inside the working memory network appears altered in patients at the earliest stage of MS. Modulation of effective connectivity is present in patients inside the executive subsystems of working memory, and could be related to adaptive cognitive control processes that may limit the clinical manifestation of MS.

Acoustic Stimulation↗
PubMed2004

Program sustainability: focus on organizational routines.

Program sustainability is an ongoing concern for most people in health promotion. However, the current notion of sustainability in organizations, namely routinization, needs refinement. This article examines organizational routines. In so doing, it refines the notion of sustainability and the assessment of routines. Drawing on the organizational literature, a routinized program is defined by the presence of routinized activities, meaning that these activities exhibit four characteristics of organizational routines: memory, adaptation, values and rules. To answer the question of how these characteristics are useful, we conducted an empirical study of the routinization of the Quebec Heart Health Demonstration Project in five community health centers. Our method consisted of a multiple-case study. We observed project activities in each center in 2000. The data came from documents and interviews with project actors. Our results show that, in one of the centers, no resources had been officially committed to project activities. Even so, the actors continued some activities on an informal basis. In another center, the activities satisfied three of the four routine characteristics. In the three others, activities satisfied all of the characteristics. These results suggest focusing the study of program sustainability on the routinization of activities resulting from it. They indicate four distinct degrees of sustainability: (1) the absence of sustainability; no program activity is continued; (2) precarious sustainability; some residual activities are pursued, at least unofficially; (3) weak sustainability; the program produces some official activities that are not routinized; and (4) sustainability through routinization; routinized activities result from the program.

Community Health Centers↗
PubMed2004

Influence of encapsulation on the in vitro percutaneous absorption of octyl methoxycinnamate.

The purpose of this study was to evaluate the in vitro transdermal permeation and skin accumulation of one ultraviolet (UV) absorber-octyl methoxycinnamate (OMC)-through pig skin and to determine the quantity of OMC in the skin surface and different pig skin layers (stratum corneum, viable epidermis, dermis, and receptor fluid). Four cases have been considered: the application of oil-in-water (O/W) and water-in-oil (W/O) emulsions containing the same filter free and encapsulated in nanocapsules (NC). The influence of the carrier on the percutaneous penetration was studied. Data showed that UV absorber exhibited increases in skin accumulation when is formulated in emulsions in free form. Skin accumulation of OMC-free in the emulsions was significantly (P < 0.05) greater than that of OMC-encapsulated for all formulations investigated. OMC-free skin accumulation ranged from 127.8 +/- 22.8 microg/cm(2) (O/W emulsion) to 172.1 +/- 12.9 microg/cm(2) (W/O emulsion). OMC-encapsulated skin accumulation ranged from 50.3 +/- 13.1 microg/cm(2) to 43.0 +/- 6.5 microg/cm(2) at NC-O/W and NC-W/O, respectively. No significant differences were found in the transdermal permeation of cinnamate for any of the formulations tested. The results of this study demonstrate that the inclusion of OMC-encapsulated in sunscreen formulations decreases the skin accumulation of the cinnamate since the in vitro release mechanism of OMC-nanocapsules is governed by hydrophobicity and crystallinity of the polymer and by the high lipophilicity of the drug. The crystallinity of the polymer have the ability of reflecting and scattering UV radiation on their own thus leading to photoprotection without the need for molecular sunscreens.

Administration, Cutaneous↗
PubMed2004

Treatment of progressive forms of multiple sclerosis by cyclophosphamide: a cohort study of 490 patients.

There are no generally effective disease-modifying drugs for progressive forms of multiple sclerosis (MS). Some MS centres use cyclophosphamide (CYC) in secondary progressive (SP) forms of MS, especially after interferon beta-1b (INFbeta-1b) treatment failure. Moreover, there are currently no approved drugs for primary progressive (PP) MS. Using the collected data of patients with progressive MS, we studied clinical patterns that predicted a good response to CYC treatment. Secondly, we compared the therapeutic response of SPMS and PPMS patients to the treatment. Data from 490 MS patients were collected. All patients presented an SP (n = 362) or PP (n = 128) form of the disease and 476 had been treated for at least one year with a monthly pulse of CYC associated with methylprednisolone (MP). CYC treatment was justified because of at least a 1-point worsening on the Expanded Disability Status Scale (EDSS) during the previous year. The EDSS score was assessed at baseline and after 6 months (M6) and 12 months (M12) of treatment. After 12 months of CYC treatment, 78.6% of SPMS and 73.5% of PPMS patients had stabilised or had an improved EDSS score. Response to CYC was not significantly different in the two progressive forms of MS. Twenty-two patients presented noticeable drug side effects, one of whom withdrew from the treatment due to intolerance. Patients with an improved EDSS at M12 had a shorter mean progressive time course (5.1 years) than patients who stabilised or worsened (7.1 years) (p = 0.02). We also observed that poor responders at M6 were also poor responders at M12 (p < 0.001). This large cohort study showed that CYC treatment was well tolerated and suggested that a better response occurred in cases with a short progressive time course. We did not find any difference in treatment response between the two progressive forms of MS. To date, no treatment is approved for PPMS and we therefore propose a trial to test the use of CYC treatment early in the course of the disease in PPMS patients with disability progression.

Adult↗
PubMed2004

[Multiple sclerosis associated with neurofibromatosis type I].

Association between neurofibromatosis type 1 (NF-1) and multiple sclerosis (MS) has been very rarely described. We report the case of a 40-year-old woman presenting familial NF-1 who had café au lait spots and cutaneous neurofibromatosis since childhood. Five years earlier, she experienced a first episode of unilateral optic neuritis, recurrent sensory and motor disturbances, then gait ataxia and pyramidal tract dysfunction with progressive walking impairment. Altered evoked potentials, CSF analysis and cerebral MRI findings were consistent with the diagnosis of MS (secondary progressive form after relapsing-remitting phase). We review major demographic, clinical and laboratory data of MS associated with NF-1 and discuss about the potential pathophisiological mechanisms implied.

Adult↗
PubMed2004

Poly-epsilon-caprolactone nanocapsules containing octyl methoxycinnamate: preparation and characterization.

This study investigates the different nanocapsules (NCs) made of poly-epsilon-caprolactone (PCL) containing the lipophilic sunscreen Escalol 557 [octyl methoxycinnamate (OMC)] and analyzes the influence of nanoparticle-based systems on light-induced decomposition of the sunscreen agent. The NCs were designed and prepared by the solvent displacement method. Formulation parameters, such as the nature and volume of the organic and aqueous phase and the nature and concentration of the surfactants and polymer, have relevant implications on NC elaboration. We investigated the influence of several technological (stirring speed: 300-800 rpm) and formulation factors [polymer amount, 195-244.5 mg; surfactant, Tween 85 (Polysorbate 85), Montanox 80 (Polysorbate 80), and Synperonic PE/F68 (Poloxamer 188) as stabilizing agents; and volume of the organic phase, 20-30 mL of acetone] on the particle size and the OMC loading capacity of the formulations--encapsulation efficiency and yield. The sizes of NC obtained were in the range of 309 to 1042 nm, the encapsulation efficiencies ranged from 93.82% to 99.97%, and yields of NC encapsulation ranged from 48.12% to 86.28%. Of all the preset experimental conditions, Montanox 80, 30 mL of acetone, 244.5 mg of polymer, and a stirring speed of 350 rpm have been selected as the best in this experimental design study. The experimental conditions selected to obtain OMC-loaded NC of 374 nm resulted in a high entrapment percentage (97.52%) and yield (82.95%). The PCL nanoparticles loaded with OMC were effective in reducing light-induced degradation of the sunscreen agent.

Acetone↗
PubMed2003

MRI/MRS of corpus callosum in patients with clinically isolated syndrome suggestive of multiple sclerosis.

Atrophy of corpus callosum (CC) related to axonal loss has previously been observed in patients at the early stage of clinically definite multiple sclerosis (CDMS). Atrophy increases with the progression of the disease. Nevertheless, no data concerning the onset of atrophy of CC are currently available. The purpose of this study is to determine if damage in callosal tissue was present at the earliest stage of MS, in a subgroup of patients presenting with a clinically isolated syndrome suggestive of MS (CISSMS), fulfilling the dissemination in space criteria according to McDonald. Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) techniques were applied to measure CC volume, magnetization transfer ratio (MTR), mean diffusivity (MD), N-acetyl aspartate/choline-containing compounds (NAA/Cho) ratio, N-acetyl aspartate/total creatine (NAA/Cr) ratio and Cho/Cr ratio inside the CC of 46 CISSMS patients and 24 sex- and age-matched controls. No atrophy of CC was observed in the CISSMS group. CC of patients was characterized by decreased MTR and increased MD. No change in the NAA/Cr ratio was observed while the NAA/Cho ratio decreased and Cho/Cr ratio increased in the splenium and the central anterior part of CC. These abnormalities were present in patients with, but also without, macroscopic lesions inside the CC. Our results indicate that diffuse structural and metabolic changes, which may be interpreted as representing predominantly myelin pathology, occur in the CC at the earliest stage of MS before any atrophy is detected.

Adult↗
PubMed2003

[Melanocytic meningitis and large congenital melanocytic naevus: neurocutaneous melanosis].

Neurological symptoms in a patient with large congenital melanocytic naevus are highly suggestive of cerebromeningeal melanoma metastasis. The presence of melanocytic cells in cerebrospinal fluid confirms this diagnosis If their malignant nature is shared with cutaneous naevocytic cells. Conversely, neurocutaneous melanosis is diagnosed when benign melanocytosis meningitis is found in patients with multiple and/or large congenital melanocytic naevus, whether cutaneous naevus cells are benign or not, or when cerebrospinal fluid cells are malignant with benign cutaneous melanocytic naevus. We report the case of a young man aged 19 presenting with multiple and large congenital melanocytic naevus who experienced transcient neurological signs and increased intracranial pressure. Cerebral neuroimaging evoked meningeal infiltration which benign melanocytic nature was supposed on CSF analysis and confirmed by necropsy findings, only 3 month after neurological onset, leading to neurocutaneous melanosis diagnosis. This rare neuroectodermal dysembryoplasia finds expression in various neurological signs, depending on patient's age and leptomeningeal and/or cerebral proliferation localization. Lumbar puncture, cerebral scanography and MRI may help diagnosis, but only histological examination can prove neurocutaneous melanosis, more often by necropsy because of poor prognosis.

Adult↗
PubMed2003

[Hashimoto's encephalitis and sleep disorders].

Hashimoto's encephalitis is a rare cause of encephalitis which is improved by corticosteroid treatment. We report the case of a 42-year-old woman who developed progressive dementia associated with episodes of recurrent discorders of consciousness which rapidly improved with corticosteroids. During these episodes, no sleep activity was recorded on the holter EEG. These discorders were reversible with treatment and a normal EEG sleep pattern reappeared. At physical examination, Hashimoto's encephalitis can mimic Creutzfeld-Jakob disease. Systematic sleep-EEG recordings can be helpful for diagnosis of sleep disorders related Hashimoto's encephalitis. This case illustrates the importance of searching for antithyroid antibodies in patients with unexplained encephalitis.

Adrenal Cortex Hormones↗
PubMed2003

[Acute heart failure in a patient treated by mitoxantrone for multiple sclerosis].

Mitoxantrone is an immunosuppressive drug usually delivered in severe relapsing remitting multiple sclerosis. It can also be used in secondary progressive and progressive relapsing remitting multiple sclerosis. Left ventricular ejection fraction has to be monitored because of the cardiotoxicity risk of mitoxantrone. Acute cardiac side effects in multiple sclerosis have not yet been described. We report the single case of an acute heart failure occurring in a cohort of more than 800 patients treated with mitoxantrone. We discuss about interruption criteria as maximal cumulative dose allowed and left ventricular ejection fraction cut off value.

Acute Disease↗
PubMed2002

Partial cloning and polymorphism of the melatonin1a (Mel1a) receptor gene in two breeds of goat with different reproductive seasonality.

The melatonin1a (Mel1a) receptor gene was cloned in two breeds of goat, one with marked seasonal ovarian activity (Alpine breed) and the other with low seasonal variations in ovulatory activity (Creole breed), to determine whether reproductive seasonality is related to the structure of the Mel1a gene. The main part of exon II was amplified by PCR using sheep sense and antisense primers in 17 Alpine and 13 Creole goats, and cDNAs were subcloned and sequenced in both directions. The results indicate the presence of an identical sequence in 12 of the 30 animals, that is, six Alpine and six Creole goats. The greatest similarity in the 784 nucleotides of exon II (primers excluded) that was obtained was found with ovine Mel1a receptor sequence (98.4%) and the differences consisted of 12 nucleotide and four amino acid changes. The presence of seven mutations compared with the previous reference sequence was observed and their combinations indicated the presence of at least five other alleles; one mutation resulted in a change in one amino acid in three Alpine goats. No difference in allelic distribution was observed between the two breeds. The results indicate that no relationship could be established between the Mel1a receptor gene structure and the expression of seasonality of reproduction in goats.

Amino Acid Sequence↗