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Armand Perret-Liaudet

Publications and source records attributed to Armand Perret-Liaudet.

10 recordsLinked to original sources
PubMed2005

Impact of standardized calibration on the inter-assay variation of 14 automated assays for the measurement of creatinine in human serum.

PURPOSE: The aim of our study was to measure the inter-assay variation and accuracy of serum creatinine assays and to assess the effect of standardized calibration procedures on this variability. METHODS: We analyzed 30 human sera and three reference materials, using 17 creatinine assays (12 colorimetric, 4 enzymatic and 1 HPLC). We compared two standardized calibration procedures, using either a reference material or secondary standards, to that recommended by the manufacturers. RESULTS: For assays calibrated according to the manufacturers' recommendations, the median inter-assay coefficient of variation (CV) was 14.2% for 20 low samples (45-150 microM), and 7.7% for 10 high samples (250-350 microM). The CV was significantly influenced by the calibration procedure, but none of the standardized calibration procedures significantly improved the inter-assay variability. However, a significant decrease in CV was noted within each type of assay method (colorimetric or enzymatic) when the standardized calibration used standards of level(s) close to the concentrations to be measured. Only the compensated Jaffe technique and the amido-hydrolase assay showed bias of less than 10%. CONCLUSIONS: Standardizing calibration procedures is unlikely to decrease the analytical variability of creatinine assays enough to allow uniform and reliable use of the equations for estimation of glomerular filtration rate.

Automation↗
PubMed2004

Pathologic prion protein spreading in the peripheral nervous system of a patient with sporadic Creutzfeldt-Jakob disease.

BACKGROUND: Involvement of the peripheral nervous system in the pathogenesis of prion diseases is becoming increasingly evident. However, pathologic protease-resistant prion protein deposition in the peripheral nerves of patients with Creutzfeldt-Jakob disease has never been demonstrated, to our knowledge. OBJECTIVE: To determine whether mutated prion protein accumulation could be shown in the peripheral nervous system of patients with sporadic Creutzfeldt-Jakob disease. DESIGN: Autopsy study. PATIENTS: Three patients with sporadic Creutzfeldt-Jakob disease. INTERVENTIONS: Study of the brain, spinal cord, and sciatic and superficial peroneal nerves by immunohistochemistry and Western blot analysis. MAIN OUTCOME MEASURE: Demonstration of protease-resistant prion protein accumulation. RESULTS: In all cases, protease-resistant prion protein accumulation was found in the brain and posterior horns of the spinal cord. In 1 case, protease-resistant prion protein deposits were also evidenced in the dorsal root ganglia and the superficial peroneal nerve. CONCLUSIONS: Protease-resistant prion protein may be found in the peripheral nervous system of some patients with sporadic Creutzfeldt-Jakob disease. However, a larger series is required to assess the incidence of peripheral nervous system involvement and to discuss the diagnostic usefulness of peripheral nerve biopsy in sporadic Creutzfeldt-Jakob disease.

Aged↗
PubMed2004

Quantitative study of spongiform change in putamen of 24 cases of Creutzfeldt-Jakob disease.

Creutzfeldt-Jakob disease (CJD) is characterized by 4 main neuropathological lesions: spongiform change, neuronal loss, astrocytic gliosis, and accumulation of pathological prion protein (PrPsc), which is partially protease-resistant (PrPres). This study focused on spongiform change (SC) in the putamen. Because SC varies from case to case, we investigated whether its quantification could provide relevant criteria to discriminate types of PrPres in CJD. SC was quantified in 24 CJD cases, 12 with PrPres type 1 (CJD-PrP1) and 12 with PrPres type 2 (CJD-PrP2), compared to 25 control cases. The study was performed by direct microscopy examination (DME) and by semiautomatic quantification (SAQ) using shape and size criteria previously described. These criteria were suitable for SC quantification in putamen in the majority of cases, except for those with microspongiosis. The results obtained by DME and SAQ methods were correlated and SC scores were compared to the types of PrPres. Sporadic CJD cases with PrPres type 2 were more affected by SC than type 1, suggesting that putamen could be a preferential site to distinguish type 1 from type 2 histologically. The origin of the difference in SC intensity according to the type of PrPres is discussed in terms of host and strain factors.

Creutzfeldt-Jakob Syndrome↗
PubMed2004

Assessment of jugular blood oxygen and lactate indices for detection of cerebral ischemia and prognosis.

Levels of jugular blood oxygen saturation (SjvO2) and lactate have been proposed as indicators of cerebral ischemia and prognosis. However, sensitivity and specificity of these markers remain unknown. We retrospectively analyzed records of a series of 43 comatose patients at risk for cerebral ischemia, mainly after head injuries or subarachnoidal hemorrhage. Their SjvO2, jugulo-arterial lactate difference (VADLactate), and lactate-oxygen index (LOI) were determined every 8 hours. An increase in VADLactate and LOI was found, indicative of ischemia on CT scan, with threshold values of 0.30 mmol/L and 0.15, respectively. Sensitivity and specificity were 100% and 64%, respectively, for the VADLactate threshold, and 90% and 55%, respectively, for the LOI threshold. Regarding prediction of a poor outcome, only an increase in VADLactate had a predictive value with a sensitivity of 100% and specificity of 67%. No threshold value with sufficient sensitivity and specificity was found for SjvO2, as indicator of either ischemia or outcome. During progression to brain death, VADLactate and LOI reached abnormal levels earlier than cerebral perfusion pressure or SjvO2. They reacted markedly to focal ischemia due to vasospasm. Hyperlactacidemia rendered VADLactate and LOI uninterpretable by causing a brain lactate influx. Present data, if confirmed by a prospective study, would justify inclusion of intermittent VADLactate and LOI determinations in the multimodal cerebral monitoring.

Brain Injuries↗
PubMed2003

The sympathetic nervous system is involved in variant Creutzfeldt-Jakob disease.

Prion epizoonoses spread from animals consumed by humans raise the question of which pathways lead to prion neuroinvasion after oral exposure of humans. Here we show that neurons of sympathetic ganglia of patients with variant Creutzfeldt-Jakob disease (vCJD) accumulate the abnormal isoform of the protein prion. This observation shows the involvement of the sympathetic nervous system in the pathogenesis of vCJD and suggests a role for GUT-associated sympathetic neurons in prion propagation in humans after oral contamination.

Adult↗
PubMed2002

Immunohistochemical localization of 14.3.3 zeta protein in amyloid plaques in human spongiform encephalopathies.

The localization of 14.3.3 proteins was studied in different subtypes of brain amyloid plaques. We examined paraffin-embedded brain sections of sporadic MV2 Creutzfeldt-Jakob disease (sCJD) with Kuru plaques, sporadic VV2 CJD with plaque-like PrP(sc) (the abnornal form of prion protein) deposits, variant CJD (vCJD) with florid plaques, Gerstmann-Straüssler-Scheinker (GSS) with multicentric plaques and of Alzheimer's disease (AD) with senile plaques. Adjacent immunostaining revealed PrP(sc) and 14.3.3 zeta deposits in the same amyloid plaques in all cases of sporadic CJD and vCJD, whereas 14.3.3 zeta was not seen in amyloid plaques of GSS with A117V, P102L and D202N mutations. The same immunostaining method using anti-betaA4 and anti-14.3.3 zeta antibodies revealed no colocalization in patients with AD. Our data suggest that 14.3.3 zeta protein could interact either with PrP or with other components of PrP(sc) deposits in CJD.

14-3-3 Proteins↗
PubMed2002

Increased detection of 14-3-3 protein in cerebrospinal fluid in Sporadic Creutzfeldt-Jakob Disease during the disease course.

Diagnosis of Creutzfeldt-Jakob Disease (CJD) is based on neurological signs associated with characteristic electroencephalographic activity or detection of 14-3-3 protein in cerebrospinal fluid. However, the time course of 14-3-3 protein release during sporadic CJD is unknown. We report two observations in which the level of the detected 14-3-3 protein increased significantly with time. These preliminary cases suggest that there may be an increased release of 14-3-3 protein during the course of CJD as already proven for iatrogenic CJD.

14-3-3 Proteins↗