Papers by ROLANDO P PECORA
Acta bioquím. clín. …, 2007
Se estudió la regulación del receptor de lipoproteína de muy baja densidad (VLDLR) en dos tipos d... more Se estudió la regulación del receptor de lipoproteína de muy baja densidad (VLDLR) en dos tipos de células que intervienen en la respuesta inflamatoria: hepatocitos (HepG2) y células linfocitarias de bazo de ratón (CMB) por agentes implicados en la inflamación: VLDL o Gemfibrozil, lipopolisacárido bacteriano (LPS) para HepG2 o Concanavalina A (ConA) para CMB. Se determinaron por citometría de flujo las subpoblaciones de CMB y de HepG2 en distintas fases del ciclo celular (G1 y G2/M) con ioduro de propidio y las VLDLR+ con VLDL fluorescente. Entre 10 a 60 por ciento de células expresaron VLDLR dependiendo de las condiciones experimentales. El enfrentamiento con LPS o ConA produjo un aumento de células VLDLR+. El tratamiento con Gemfibrozil disminuyó el número de hepatocitos en reposo VLDLR+ pero incrementó significativamente (más de dos veces) los hepatocitos VLDLR+ en fase G2/M. En los cultivos de CMB Gemfibrozil aumentó por igual el porcentaje de células VLDLR+ quiescentes y en G2/M. El comportamiento de estos tipos celulares con VLDL fue distinto: CMB no mostró cambios en las subpoblaciones VLDLR+, los hepatocitos mostraron disminución de VLDLR+ tanto en fase G1 como en fase G2/M. Se concluyó que el estudio de la regulación de VLDLR en distintas células facilitará el diseño de fármacos específicos para el tratamiento de enfermedades de etiología inflamatoria. Palabras clave: inflamación * lipoproteínas * receptor de lipoproteína de muy baja densidad * Gemfibrozil Summary The regulation of the VLDL receptor (VLDLR) by molecules involved in the inflammation process (lipopolysaccharide, LPS; Concanavalin A, ConA, VLDL or Gemfibrozil) in two cellular types implied in the inflammatory response, hepatocytes (HepG2) and lymphocitary cells from mice spleen (CMB), was studied. Different subpopulations of CMB and HepG2 in different cell cycle phases (G1 and G2/M) were analyzed using flow citometry
Journal of dairy science, 2010
We investigated how protein changes occur, at the primary or higher structural levels, when prote... more We investigated how protein changes occur, at the primary or higher structural levels, when proteins are exposed to UV or fluorescent (FL) light while in the complex matrix, milk. Whole milk (WM) or skim milk (SM) samples were exposed to FL or UV light from 0 to 24h at 4°C. Protein oxidation was evaluated by the formation of protein carbonyls (PC), dityrosine bond (DiTyr), and changes in molecular weight (protein fragmentation and polymerization). Oxidative changes in AA residues were measured by PC. Dityrosine and N'-formylkynurenine (NFK), a carbonylation derivative of Trp, were measured by fluorometry. Protein carbonyls increased as a function of irradiation time for both WM and SM. The initial rate for PC formation by exposure to FL light (0.25 or 0.27 nmol/h for WM and SM, respectively) was slower than that following exposure to UV light (1.95 or 1.20 nmol/h, respectively). The time course of NFK formation resembled that of PC. After 24h of UV exposure, SM had significantly...
International Journal of Food Science Technology, Apr 1, 1989
... subpoblaciones de linfocitos CD4+ y/o CD25+ se utilizaron anticuerpos monoclonales anti-CD4 o... more ... subpoblaciones de linfocitos CD4+ y/o CD25+ se utilizaron anticuerpos monoclonales anti-CD4 o anti-CD25 marcados con Ficoeritrina (fluorescente rojo) (1 µg/10 6 células, Pharmingen, SanDiego, CA, EE ... Marx N, Kehrle B, Kohlhammer K, Grub M, Koenig W, Hombach V, et al ...
Journal of Dairy Science, Jan 6, 2013
levels. Our results highlight the importance of protein oxidative status in milk powder and its r... more levels. Our results highlight the importance of protein oxidative status in milk powder and its relationship to other related quality parameters, such as protein integrity and dispersibility. Our findings suggest that the understanding of such relationships could help in developing quality differentiation for different types of milk powders in the product market.
Journal of dairy science, 2010
We investigated how protein changes occur, at the primary or higher structural levels, when prote... more We investigated how protein changes occur, at the primary or higher structural levels, when proteins are exposed to UV or fluorescent (FL) light while in the complex matrix, milk. Whole milk (WM) or skim milk (SM) samples were exposed to FL or UV light from 0 to 24h at 4°C. Protein oxidation was evaluated by the formation of protein carbonyls (PC), dityrosine bond (DiTyr), and changes in molecular weight (protein fragmentation and polymerization). Oxidative changes in AA residues were measured by PC. Dityrosine and N'-formylkynurenine (NFK), a carbonylation derivative of Trp, were measured by fluorometry. Protein carbonyls increased as a function of irradiation time for both WM and SM. The initial rate for PC formation by exposure to FL light (0.25 or 0.27 nmol/h for WM and SM, respectively) was slower than that following exposure to UV light (1.95 or 1.20 nmol/h, respectively). The time course of NFK formation resembled that of PC. After 24h of UV exposure, SM had significantly...
Journal of The Science of Food and Agriculture, 1987
Total, non-volatile free fatty acids (FFA) content was determined in hake muscle during fkh stora... more Total, non-volatile free fatty acids (FFA) content was determined in hake muscle during fkh storage in ice. FFA increased linearly in every season according to freshness loss as determined by sensory scoring. FFA determination is proposed as a valuable alternative to sensory scoring in determining fkh deterioration in ice.
Journal of Dairy Science, 2013
Journal of Dairy Science, 2013
levels. Our results highlight the importance of protein oxidative status in milk powder and its r... more levels. Our results highlight the importance of protein oxidative status in milk powder and its relationship to other related quality parameters, such as protein integrity and dispersibility. Our findings suggest that the understanding of such relationships could help in developing quality differentiation for different types of milk powders in the product market.
Journal of the Science of Food and Agriculture, 1987
Total, non-volatile free fatty acids (FFA) content was determined in hake muscle during fkh stora... more Total, non-volatile free fatty acids (FFA) content was determined in hake muscle during fkh storage in ice. FFA increased linearly in every season according to freshness loss as determined by sensory scoring. FFA determination is proposed as a valuable alternative to sensory scoring in determining fkh deterioration in ice.
Journal of Food Science, 1987
Edible mushrooms (Boletus tropicus and Boletus granulatus) were comparatively analyzed for eight ... more Edible mushrooms (Boletus tropicus and Boletus granulatus) were comparatively analyzed for eight essential elements by atomic absorption spectrophotometry. Values obtained for Fe and Mn were three times higher in B. tropicus than in B. granulatus, whereas similar values were obtained with both species for K, Ca, Zn, Mn and Cu. No Co was detected in the samples analyzed.
International Journal of Food Science & Technology, 2007
Biochemical and Biophysical Research Communications, 1997
Oxidized lipoproteins have been involved in the pathogenesis of atherosclerosis and atherosclerot... more Oxidized lipoproteins have been involved in the pathogenesis of atherosclerosis and atherosclerotic lesions contain oxidized low density lipoprotein. Conversely, the presence of oxidized high density lipoprotein (HDL)in vivohas not been clearly established. Oxidation of HDLin vitromodels produces an increase in peroxidized lipids and the appearance of apolipoprotein A-I (apo A-I) oligomers. We investigated the oxidative status of HDL in anin
Biochemical and Biophysical Research Communications, 1997
scarce indirect evidence advances the possibility of its Oxidized lipoproteins have been involved... more scarce indirect evidence advances the possibility of its Oxidized lipoproteins have been involved in the occurrence, i.e., it is known that HDL is modified in an pathogenesis of atherosclerosis and atherosclerotic leoxidatively way by human polymorphonuclear leukosions contain oxidized low density lipoprotein. Concytes probably due to the actions of superoxide anions versely, the presence of oxidized high density lipopro-(4). Another potential source of oxidized HDL could be tein (HDL) in vivo has not been clearly established. HDL of the interstitial fluid bathing the epidermis of Oxidation of HDL in vitro models produces an increase uv-exposed skin (5). in peroxidized lipids and the appearance of apolipo-HDL has been oxidized in vitro under different condiprotein A-I (apo A-I) oligomers. We investigated the tions: uv irradiation (5), incubation with Fe 2/ , Mn 2/ , oxidative status of HDL in an in vivo model: the hyper-Cu 2/ (6, 7, 8) or prolonged storage at 4ЊC without EDTA cholesterolemic chicken. The HDLs from control and (9). Under all these conditions, some common modifihyperlipemic animals were analyzed for the content cations of HDL were observed like an increase in peroxof lipid peroxides employing spectroscopic and fluoidized lipids and the appearance of apolipoprotein A-I rescence techniques, for the level of apo A-I oligomerization, and for susceptibility to in vitro oxidation. (apo A-I) oligomers. Moreover, we have described that HDL from hypercholesterolemic chickens was more chicken HDL oxidized by heatin or uv irradiation in peroxidized (as detected by fluorescence), had higher the absence of EDTA forms a supramolecular aggreamount of oligomeric apo A-I, and was oxidized to a gate that produced neurodegeneration both on undifgreater extent by uv irradiation than that of control ferentiated and on differentiated cerebral neurons in animals. We speculate that apo A-I oligomerization culture (10). The presence of aggregated HDL in vivo could be a key step in the atheroma formation. ᭧ 1997 could be of relevance in the pathogenesis of Alzeheim-Academic Press
Biotechnology letters, 2002
A cell density monitor, comprising parts of a liquid chromatography system, was adapted for on-li... more A cell density monitor, comprising parts of a liquid chromatography system, was adapted for on-line real-time measurement of bacterial cell density up to 75 g l −1. The device dilutes the sample containing cells and measures the absorbancy at 280 nm. This detector gives an excellent correlation with off-line measurements, good reproducibility, a low limit of detection (3.5 mg l −1), and becomes a low cost alternative for fermentation monitoring in small stirred bioreactors.
Acta bioquím. clín. …, 2007
Se estudió la regulación del receptor de lipoproteína de muy baja densidad (VLDLR) en dos tipos d... more Se estudió la regulación del receptor de lipoproteína de muy baja densidad (VLDLR) en dos tipos de células que intervienen en la respuesta inflamatoria: hepatocitos (HepG2) y células linfocitarias de bazo de ratón (CMB) por agentes implicados en la inflamación: VLDL o Gemfibrozil, lipopolisacárido bacteriano (LPS) para HepG2 o Concanavalina A (ConA) para CMB. Se determinaron por citometría de flujo las subpoblaciones de CMB y de HepG2 en distintas fases del ciclo celular (G1 y G2/M) con ioduro de propidio y las VLDLR+ con VLDL fluorescente. Entre 10 a 60 por ciento de células expresaron VLDLR dependiendo de las condiciones experimentales. El enfrentamiento con LPS o ConA produjo un aumento de células VLDLR+. El tratamiento con Gemfibrozil disminuyó el número de hepatocitos en reposo VLDLR+ pero incrementó significativamente (más de dos veces) los hepatocitos VLDLR+ en fase G2/M. En los cultivos de CMB Gemfibrozil aumentó por igual el porcentaje de células VLDLR+ quiescentes y en G2/M. El comportamiento de estos tipos celulares con VLDL fue distinto: CMB no mostró cambios en las subpoblaciones VLDLR+, los hepatocitos mostraron disminución de VLDLR+ tanto en fase G1 como en fase G2/M. Se concluyó que el estudio de la regulación de VLDLR en distintas células facilitará el diseño de fármacos específicos para el tratamiento de enfermedades de etiología inflamatoria. Palabras clave: inflamación * lipoproteínas * receptor de lipoproteína de muy baja densidad * Gemfibrozil Summary The regulation of the VLDL receptor (VLDLR) by molecules involved in the inflammation process (lipopolysaccharide, LPS; Concanavalin A, ConA, VLDL or Gemfibrozil) in two cellular types implied in the inflammatory response, hepatocytes (HepG2) and lymphocitary cells from mice spleen (CMB), was studied. Different subpopulations of CMB and HepG2 in different cell cycle phases (G1 and G2/M) were analyzed using flow citometry
Acta bioquímica …, 2007
... subpoblaciones de linfocitos CD4+ y/o CD25+ se utilizaron anticuerpos monoclonales anti-CD4 o... more ... subpoblaciones de linfocitos CD4+ y/o CD25+ se utilizaron anticuerpos monoclonales anti-CD4 o anti-CD25 marcados con Ficoeritrina (fluorescente rojo) (1 µg/10 6 células, Pharmingen, SanDiego, CA, EE ... Marx N, Kehrle B, Kohlhammer K, Grub M, Koenig W, Hombach V, et al ...
Journal of Dairy Science, 2005
We developed a simple microtechnique to measure lipids in milk by UV spectrophotometry. This tech... more We developed a simple microtechnique to measure lipids in milk by UV spectrophotometry. This tech- nique is based upon the property of fatty acids to ab- sorb UV light proportional to their concentration. Samples of powdered or fluid milk (30 or 60 µL) were added to 3 mL of analytic grade ethanol and stored at −20°C for at least 1
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Papers by ROLANDO P PECORA