ABSTRACT
In this study, the feasibility of storing Marmande tomatoes (Solanum lycopersicum, cv Rojito) under hypobaric conditions was evaluated. The fruits were sorted into four lots of 72 fruits each. One lot was considered as a control, and the fruits were kept in the open box, while the fruits of the rest of the three remaining lots were enclosed in airtight containers and subjected to 101, 75 and 50 Kpa, respectively. Control fruits and airtight containers were kept at room temperature, and every three days from the beginning of the experiment the following main quality parameters were analysed: ethylene production rate, firmness, colour, total solids content, ascorbic acid, total phenolics and pigments, as well as a sensory analysis carried out by panellists. The results show that sub-atmospheric storage led a reduction in ethylene production, which was associated with a delay in ripening. The differences in the evolution of pigments were very significant, while a large degradation of chlorophylls was observed in the control fruits and in those kept at 101 kPa, in the fruits kept at 75 kPa and 50 kPa the degradation was much slower. In relation to carotenoid pigments, it was observed that sub-atmospheric treatments delayed their appearance compared to control and 101 kPa fruits. In relation to other quality parameters, it was found that control fruit and fruit held at 101 kPa softened more rapidly than fruit under sub-atmospheric conditions, whose loss of firmness was more gradual with differences found only at 9 and 12 days of storage with respect to fruit firmness at harvest. The appearance of these fruits was evaluated with the same score as at the time of harvesting, during 9 of the 12 days of the experiment, then a positive effect of sub-atmospheric treatments was also found in the sensory analysis. The results suggest that sub-atmospheric storage could be a suitable method of increasing the shelf-life of fruits.
ABSTRACT
Poli (ADP-Ribosa) polimerasa (PARP-1) cataliza la ADP ribosilación de proteínas usando NAD(+) como sustrato. La activación de PARP-1 conduce a la depleción intracelular de NAD(+). El daño por isquemia-reperfusión (IR) induce una activación excesiva de PARP-1 y la muerte celular por consumo masivo de ATP. Nuestra hipótesis de trabajo es que la excesiva expresión tubular de PARP-1 en riñones humanos trasplantados es una de las causas directas de la inducción de necrosis tubular aguda (NTA) y contribuye al retraso de la función renal del injerto. Material y Métodos: Estudiamos 193 biopsias de trasplante renal (95 preimplante biopsia de donante y 98 postrasplante) incluidas en parafina con diferentes grados de NTA y 65 biopsias renales de donante sin NTA. La NTA se estratificó en cuatro grados: ausente (0); leve (1) [50%]. La expresión nuclear de PARP-1 fue evaluada mediante inmunohistoquímica con el kit de polimeros conjugado con peroxidasa MasVision y el anticuerpo anti- PARP-1 (clón PARP01) y valorada semicuantitativamente de 0 a 3. Resultados: La expresión nuclear de PARP-1 antecedió a los cambios morfológicos sugerentes de NTA. Principalmente la inmunotinción se localizó en los núcleos de células tubulares, cuando fue intensa la lesión también apareció en glomérulos (epitelio de la cápsula de Bowman y células endoteliales de capilares glomerulares). La inmunotición fue observable hasta fases finales de la necrosis tubular. La totalidad de las 95 biopsias renales pre-trasplante con NTA grado 1 (86%) o grado 2 (14%) mostraron expresión nuclear de PARP-1 en túbulos. Las 98 biopsias postrasplante con NTA mostraron expresión más intensa de PARP-1 [grado 2 (45%), grado 3 (25%)]. El grado de NTA se correlacionó significantivamente con la expresión de PARP- 1(r=0,565, p=0,0001, test de Pearson), con una expresión media 2,74±0,45 en los casos de NTA severa frente a 1,94±0,74 en los casos de NTA leve y 0,29±0,45 en los casos sin NTA (p=0,0001, test ANOVA de una vía). En conclusión, PARP-1 está vinculado a la inducción de NTA y desempeña un papel importante en el comportamiento de la función precoz del injerto renal ya que está correlacionada significativamente con el tiempo en recuperar la diuresis eficaz (r=0,578, p=0,0001, test de Pearson) y con los niveles séricos de creatinina en el momento de la biopsia (r=0,649), y a los 3 meses (r=0,363, p=0,0001, test de Pearson) pero no a los 6 y 12 meses postrasplante
Poly (ADP-Ribose) Polymerase (PARP-1) catalyzes ADP-ribosylation of proteins using NAD(+) as substrate. Its overactivation leads to massive NAD+ consumption and ATP depletion. The ischemia/reperfusion injury (IR) induces PARP-1 overactivation and leads to cellular necrosis by massive ATP consumption. Our working hypothesis was that massive PARP-1 tubular expression in allograft human kidneys are a direct cause of acute tubular necrosis (ATN) and contribute to delay in early recovery of renal function (RRF) of the transplanted organ. Material and Methods:A total of 193 paraffin embedded renal allograft biopsies (95 pre-implant donor biopsies and 98 post-implant) with several ATN degrees, and 65 control renal biopsies from donors without ATN were studied. ATN degree was classified as: Absence (0); mild (1) [50%]. Nuclear expression of PARP-1 in tubular cells was evaluated by immunohistochemistry using polymer-conjugate MasVision kit and the monoclonal antibody anti-PARP-1 (clone PAR01). It was semiquantitatively determined, and scored from 0 to 3. Results: The nuclear PARP-1 preceded the morphological features of ATN. Immunostaining was located mainly in tubular cells nuclei, in cases of intense injury also was observed in glomeruli (capillary endothelial cells and epithelial cells of Bowmans capsule). Immunostaining was observed until advanced ATN condition. All 95 pre-transplant renal biopsies with ATN degree 1 (86%) or degree 2 (14%) showed tubular nuclei PARP-1 expression. The 98 post-transplant biopsies with ATN showed more intense expression of PARP-1 [degree 2 (45%), degree 3 (25%)]. Statistically significant relationship between ATN degree and PARP-1 expression was found (r=0.565, p=0.0001, Pearson test), with a mean expression of 2.74±0.45 in sever ATN cases versus 1.94±0.74 in mild ATN cases, and 0.29±0.45 in non-ATN cases (p=0.0001, one way ANOVA test). In conclusion, PARP-1 are linked to induction of ATN, and plays an important role in early graft renal function. This fact is indicated by the stati! stically significant relation with delay in total RRF (r=0.578, p=0.0001, Pearson test), creatinine serum levels at biopsy time (r=0.649) and at 3 months (r=0.363, p=0.0001, Pearson test), but not at 6 or 12 months post-transplant
