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Marc Paccalin

Publications and source records attributed to Marc Paccalin.

13 recordsLinked to original sources
PubMed2006

Peripheral p70S6k levels and emotional memory in patients with Alzheimer's disease.

Alzheimer's disease (AD) is clinically marked at the onset, by memory disturbances affecting explicit memory. Emotional explicit memory is enhanced in normal subjects and remained less affected at the beginning of AD. The kinase p70S6k participates in the control of protein translation and seems also implicated in the process of synaptic plasticity and the formation of memory at the molecular level. In a previous study, we have shown that peripheral p70S6k level is correlated with the decline of cognitive and memory functions in patients with AD. The goal of the present study was to analyse emotional and neutral explicit memory in AD patients and to evaluate the levels of active p70S6k in lymphocytes by western blots. The results reveal that the difference between emotional and neutral memories are correlated with the levels of peripheral p70S6k in patients with AD, as well as with the global cognitive scores assessed by the Mini Mental Status Examination. The decline of emotional memory in AD patients is reflected by the decrease of p70S6k levels.

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PubMed2006

Activated mTOR and PKR kinases in lymphocytes correlate with memory and cognitive decline in Alzheimer's disease.

BACKGROUND: The control of translation, involving the kinases mTOR (mammalian target of rapamycin) and PKR (double-stranded RNA-dependent protein kinase), modulates cell survival and death and is altered in the brains of patients with Alzheimer's disease (AD). In AD increased susceptibility of lymphocytes to apoptosis has been reported. METHODS: We investigated the level of the kinases mTOR and PKR and the eukaryotic initiation factor 2alpha (eIF2alpha) in lymphocytes of patients with AD in comparison with controls. In AD patients we also looked for a correlation between activated proteins and cognitive and memory tests. RESULTS: We report significant alterations of the levels of these kinases and eIF2alpha in lymphocytes of AD patients that were also significantly correlated with cognitive and memory test scores. CONCLUSION: These results suggest that the levels of mTOR, PKR and eIF2alpha in lymphocytes could follow the cognitive decline in AD.

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PubMed2006

Lack of correlation between nutritional status and seroprotection against influenza in a long term care facility.

UNLABELLED: We conducted a prospective study in a long-term care facility. Virologic diagnosis was assessed using viral isolation, polymerase chain reaction and serology for all patients with a flu-like syndrome. Albumin, vitamins and trace elements were also measured. RESULTS: The risk of influenza increased 6.5-fold in patients with an antibody titer of 40 during the influenza outbreak (P=0.04). Micronutrients and vitamins deficiencies were important. Patients with antibody titer >1:40 could still be infected by the virus without correlation with the nutritional status. CONCLUSION: Humoral protection with a titer >1:40 might not be protective in the elderly. Nutritional deficiencies were too prevalent to detect any effect on the results.

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PubMed2005

[Automobile driving among patients with dementia. Survey in the Poitou-Charentes region].

OBJECTIVES: To determine the characteristics of drivers with dementia and analyze their driving habits. METHODS: The study was conducted among neurologists and geriatricians in the Poitou-Charentes region. We asked 75 physicians to question (according to a structured questionnaire) the patients they saw in January 2004 who were known to suffer from dementia, defined by a Folstein Mini-Mental State (MMS) score pound 25. We compared the epidemiologic characteristics of drivers and nondrivers and described their driving habits. RESULTS: Of the 75 practitioners asked to participate, 27 (36%) accepted and interviewed 146 patients, 74 women and 72 men. Their mean MMS score was 17.6 +/- 5.6 [0-25]. In all, 52 were still driving at the time of the interview, and 48 had stopped, 9 because of motor vehicle accidents. Logistic regression analysis revealed 3 significant variables that differed between the drivers and the nondrivers: drivers were mainly male (p=0.0002), younger (p=0.001) and more recently diagnosed (p=0.003). Half those still driving drove only occasionally (< or =3 times a week), usually during daylight and for short distances. One driver was involved in an accident the year before. DISCUSSION: Patients appeared to be aware of the dangers of driving and avoided taking risks. The MMS score predicted driving status. It is essential to develop simple tests to assess driving ability as objectively as possible.

Accidents, Traffic↗
PubMed2005

Localized amyloidosis: a survey of 35 French cases.

Since the prognosis of localized amyloidosis remains unclear, we conducted a survey to define the characteristics and the course of this disease. The charts of 35 patients with either laryngeal (14 patients), tracheobronchial (10 patients), colonic (1 patient), or lower urinary tract amyloidosis (10 patients) were analyzed. The average age at diagnosis was 52.7+/-12 years (range 33-73 years). The amyloid protein type was specified to be amyloid light chain (AL) in 15 cases. All patients had undergone additional biopsies (accessory salivary glands, rectal, fat pad and bone marrow aspirates) to rule out a systemic disease. Symptomatic treatments included endoscopic excision and laser therapy. Colchicine and chemotherapy with prednisone and melphalan were prescribed with limited success. During a mean follow-up period of 6.1+/-5.3 years no patient developed a systemic form of amyloidosis. Six deaths were reported, one related to the disease because of a fatal airway hemorrhage. We suggest that immunolabeling studies should be more routinely performed. There was no risk of developing a systemic disease from local amyloid deposits in our survey. However, local evolution can be life-threatening. Such patients should be referred to specialist centers for further evaluation. Management requires close follow-up to exclude recurrence and to determine the appropriate symptomatic treatment.

Adult↗
PubMed2005

mTOR/p70S6k signalling alteration by Abeta exposure as well as in APP-PS1 transgenic models and in patients with Alzheimer's disease.

In Alzheimer's disease, neuropathological hallmarks include the accumulation of beta-amyloid peptides (Abeta) in senile plaques, phosphorylated tau in neurofibrillary tangles and neuronal death. Abeta is the major aetiological agent according to the amyloid cascade hypothesis. Translational control includes phosphorylation of the kinases mammalian target of rapamycin (mTOR) and p70S6k which modulate cell growth, proliferation and autophagy. It is mainly part of an anti-apoptotic cellular signalling. In this study, we analysed modifications of mTOR/p70S6k signalling in cellular and transgenic models of Alzheimer's disease, as well as in lymphocytes of patients and control individuals. Abeta 1-42 produced a rapid and persistent down-regulation of mTOR/p70S6k phosphorylation in murine neuroblastoma cells associated with caspase 3 activation. Using western blottings, we found that phosphorylated forms of mTOR and p70S6k are decreased in the cortex but not in the cerebellum (devoid of plaques) of double APP/PS1 transgenic mice compared with control mice. These results were confirmed by immunohistochemical methods. Finally, the expression of phosphorylated p70S6k was significantly reduced in lymphocytes of Alzheimer's patients, and levels of phosphorylated p70S6k were statistically correlated with Mini Mental Status Examination (MMSE) scores. Taken together, these findings demonstrate that the mainly anti-apoptotic mTOR/p70S6k signalling is altered in cellular and transgenic models of Alzheimer's disease and in peripheral cells of patients, and could contribute to the pathogenesis of the disease.

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PubMed2002

Infective endocarditis after transrectal prostatic biopsy.

We report the first case of infective endocarditis secondary to transrectal prostatic biopsy, occurring 2 weeks later in a patient with no obvious risk factors. Enterococcus faecalis was isolated in blood and urine cultures. This case suggests that infective endocarditis can be associated with transrectal procedures.

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