Papers by Nancy Hernandez
PLOS One, 2012
Creutzfeldt-Jakob disease (CJD) is the most frequent human Prion-related disorder (PrD). The dete... more Creutzfeldt-Jakob disease (CJD) is the most frequent human Prion-related disorder (PrD). The detection of 14-3-3 protein in the cerebrospinal fluid (CSF) is used as a molecular diagnostic criterion for patients clinically compatible with CJD. However, there is a pressing need for the identification of new reliable disease biomarkers. The pathological mechanisms leading to accumulation of 14-3-3 protein in CSF are not fully understood, however neuronal loss followed by cell lysis is assumed to cause the increase in 14-3-3 levels, which also occurs in conditions such as brain ischemia. Here we investigated the relation between the levels of 14-3-3 protein, Lactate dehydrogenase (LDH) activity and expression of the prion protein (PrP) in CSF of sporadic and familial CJD cases. Unexpectedly, we found normal levels of LDH activity in CJD cases with moderate levels of 14-3-3 protein. Increased LDH activity was only observed in a percentage of the CSF samples that also exhibited high 14-3-3 levels. Analysis of the PrP expression pattern in CSF revealed a reduction in PrP levels in all CJD cases, as well as marked changes in its glycosylation pattern. PrP present in CSF of CJD cases was sensitive to proteases. The alterations in PrP expression observed in CJD cases were not detected in other pathologies affecting the nervous system, including cases of dementia and tropical spastic paraparesis/HTLV-1 associated myelopathy (HAM/TSP). Time course analysis in several CJD patients revealed that 14-3-3 levels in CSF are dynamic and show a high degree of variability during the end stage of the disease. Post-mortem analysis of brain tissue also indicated that 14-3-3 protein is upregulated in neuronal cells, suggesting that its expression is modulated during the course of the disease. These results suggest that a combined analysis of 14-3-3 and PrP expression pattern in CSF is a reliable biomarker to confirm the clinical diagnosis of CJD patients and follow disease progression.
PLoS ONE, 2012
Creutzfeldt-Jakob disease (CJD) is the most frequent human Prion-related disorder (PrD). The dete... more Creutzfeldt-Jakob disease (CJD) is the most frequent human Prion-related disorder (PrD). The detection of 14-3-3 protein in the cerebrospinal fluid (CSF) is used as a molecular diagnostic criterion for patients clinically compatible with CJD. However, there is a pressing need for the identification of new reliable disease biomarkers. The pathological mechanisms leading to accumulation of 14-3-3 protein in CSF are not fully understood, however neuronal loss followed by cell lysis is assumed to cause the increase in 14-3-3 levels, which also occurs in conditions such as brain ischemia. Here we investigated the relation between the levels of 14-3-3 protein, Lactate dehydrogenase (LDH) activity and expression of the prion protein (PrP) in CSF of sporadic and familial CJD cases. Unexpectedly, we found normal levels of LDH activity in CJD cases with moderate levels of 14-3-3 protein. Increased LDH activity was only observed in a percentage of the CSF samples that also exhibited high 14-3-3 levels. Analysis of the PrP expression pattern in CSF revealed a reduction in PrP levels in all CJD cases, as well as marked changes in its glycosylation pattern. PrP present in CSF of CJD cases was sensitive to proteases. The alterations in PrP expression observed in CJD cases were not detected in other pathologies affecting the nervous system, including cases of dementia and tropical spastic paraparesis/HTLV-1 associated myelopathy (HAM/TSP). Time course analysis in several CJD patients revealed that 14-3-3 levels in CSF are dynamic and show a high degree of variability during the end stage of the disease. Post-mortem analysis of brain tissue also indicated that 14-3-3 protein is upregulated in neuronal cells, suggesting that its expression is modulated during the course of the disease. These results suggest that a combined analysis of 14-3-3 and PrP expression pattern in CSF is a reliable biomarker to confirm the clinical diagnosis of CJD patients and follow disease progression.
Journal of Ethnopharmacology, 2000
Preliminary studies of flavonoids have been realised in five native species from Tafı́ del... more Preliminary studies of flavonoids have been realised in five native species from Tafı́ del Valle (Tucumán, Argentina) used in popular medicine. Most of compounds detected were flavonoids mono and dihydroxylated in B ring. Screening for antimicrobial activity against Gram positive and Gram negative microorganisms has been realised with Lippia turbinata, Satureja parvifolia, Sambucus peruviana, Verbena officinalis and Chenopodium graveolens. The total extracts of flavonoids of each plant were tested and four species studied showed antimicrobial activity.
Journal of Ethnopharmacology, 2000
Preliminary studies of flavonoids have been realised in five native species from Tafí del Valle (... more Preliminary studies of flavonoids have been realised in five native species from Tafí del Valle (Tucumán, Argentina) used in popular medicine. Most of compounds detected were flavonoids mono and dihydroxylated in B ring. Screening for antimicrobial activity against Gram positive and Gram negative microorganisms has been realised with Lippia turbinata, Satureja par6ifolia, Sambucus peru6iana, Verbena officinalis and Chenopodium gra6eolens. The total extracts of flavonoids of each plant were tested and four species studied showed antimicrobial activity.
Journal of Electroanalytical Chemistry, 2001
Electrodeposition of silver on a poly(o-aminophenol) (POAP) modified platinum electrode was studi... more Electrodeposition of silver on a poly(o-aminophenol) (POAP) modified platinum electrode was studied by using cyclic voltammetry and chronoamperometry techniques. Results suggest that this process occurs at the polymer electrode interface. The polymer film is rather indifferent to the electrodeposition of silver because of the low conductivity of the film at potentials where crystallization occurs. Experimental transients indicated that at very short times the process follows a three-dimensional and progressive nucleation pattern with diffusion controlled growth. At pH 5, the formation of silver-polymer amino-complexes may take place.
Journal of Electroanalytical Chemistry, 2001
Electrodeposition of silver on a poly(o-aminophenol) (POAP) modified platinum electrode was studi... more Electrodeposition of silver on a poly(o-aminophenol) (POAP) modified platinum electrode was studied by using cyclic voltammetry and chronoamperometry techniques. Results suggest that this process occurs at the polymer ∣ electrode interface. The polymer film is rather indifferent to the electrodeposition of silver because of the low conductivity of the film at potentials where crystallization occurs. Experimental transients indicated that at very short times the process follows a three-dimensional and progressive nucleation pattern with diffusion controlled growth. At pH 5, the formation of silver-polymer amino-complexes may take place.
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Papers by Nancy Hernandez