279 research outputs found
Effect Of Dietary Folate Restriction On Colon Carcinogenesis In Dna Polymerase β Haploinsufficient Mice
The data presented in this research is central to establishing the role that the base excision repair pathway (BER) plays in the development and progression of colon cancer when dietary folate is deficient. Both cellular folate restriction and BER deficiencies have been shown to result in the accumulation of endogenous damage and lesions that could eventually develop into carcinogenesis. In this study, a dietary folate deficiency (FD) resulted in a significant increase in aberrant crypt foci (ACF) formation and triggered liver tumorogenesis in wildtype (WT) animals, as did a BER deficiency in DNA polymerase Î’ haploinsufficient (Î’-pol+/-) mice exposed to 1, 2-dimethylhydrazine (DMH), a known colon and liver carcinogen. We combined both folate restriction and a BER deficiency to determine the fate of colon tissue after exposure to DMH. Of interest, we show that this model supports a protection against colon carcinogenesis. FD attenuated onset and progression of ACF and prevented liver tumorigenesis in Î’-pol haploinsufficient mice. Analysis of the data suggests that the mechanism by which this phenomenon occurs appears to be through an elevation in DNA damage that signals recruitment of PARP enzymes to the site of damage, however, with a deficiency in BER, PARP function in DNA repair is futile leading to a depletion of cellular energetic levels. This energetic stress is sensed by cell death machinery and as such apoptosis is invoked
Critical Behavior in the Gravitational Collapse of a Scalar Field with Angular Momentum in Spherical Symmetry
We study the critical collapse of a massless scalar field with angular
momentum in spherical symmetry. In order to mimic the effects of angular
momentum we perform a sum of the stress-energy tensors for all the scalar
fields with the same eigenvalue, l, of the angular momentum operator and
calculate the equations of motion for the radial part of these scalar fields.
We have found that the critical solutions for different values of l are
discretely self-similar (as in the original l=0 case). The value of the
discrete, self-similar period, Delta_l, decreases as l increases in such a way
that the critical solution appears to become periodic in the limit. The mass
scaling exponent, gamma_l, also decreases with l.Comment: 10 pages, 8 figure
Accurate Evolutions of Orbiting Binary Black Holes
We present a detailed analysis of binary black hole evolutions in the last orbit and demonstrate consistent and convergent results for the trajectories of the individual bodies. The gauge choice can significantly affect the overall accuracy of the evolution. It is possible to reconcile certain gauge-dependent discrepancies by examining the convergence limit. We illustrate these results using an initial data set recently evolved by Brügmann et al. [Phys. Rev. Lett. 92, 211101 (2004)]. For our highest resolution and most accurate gauge, we estimate the duration of this data set's last orbit to be approximately 59MADM
Electronic nose and isotope ratio mass spectrometry in combination with chemometrics for the characterization of the geographical origin of Italian sweet cherries
Sweet cherries from two Italian regions, Apulia and Emilia Romagna, were analysed using electronic nose
(EN) and isotope ratio mass spectrometry (IRMS), with the aim of distinguishing them according to their
geographic origin. The data were elaborated by statistical techniques, examining the EN and IRMS datasets
both separately and in combination. Preliminary exploratory overviews were performed and then
linear discriminant analyses (LDA) were used for classification. Regarding EN, different approaches for
variable selection were tested, and the most suitable strategies were highlighted. The LDA classification
results were expressed in terms of recognition and prediction abilities and it was found that both EN and
IRMS performed well, with IRMS showing better cross-validated prediction ability (91.0%); the EN–IRMS
combination gave slightly better results (92.3%). In order to validate the final results, the models were
tested using an external set of samples with excellent results
Characterization of metabolic profiles and lipopolysaccharide effects on porcine vascular wall mesenchymal stem cells
The link between metabolic remodeling and stem cell fate is still unclear. To explore this topic, the metabolic profile of porcine vascular wall mesenchymal stem cells (pVW-MSCs) was investigated. At the first and second cell passages, pVW-MSCs exploit both glycolysis and cellular respiration to synthesize adenosine triphosphate (ATP), but in the subsequent (third to eighth) passages they do not show any mitochondrial ATP turnover. Interestingly, when the first passage pVW-MSCs are exposed to 0.1 or 10 μg/ml lipopolysaccharides (LPSs) for 4 hr, even if ATP synthesis is prevented, the spare respiratory capacity is retained and the glycolytic capacity is unaffected. In contrast, the exposure of pVW-MSCs at the fifth passage to 10 μg/ml LPS stimulates mitochondrial ATP synthesis. Flow cytometry rules out any reactive oxygen species (ROS) involvement in the LPS effects, thus suggesting that the pVW-MSC metabolic pattern is modulated by culture conditions via ROS-independent mechanisms
Low-Protein Diets in Diabetic Chronic Kidney Disease (CKD) Patients: Are They Feasible and Worth the Effort?
Low-protein diets (LPDs) are often considered as contraindicated in diabetic patients, and are seldom studied. The aim of this observational study was to provide new data on this issue. It involved 149 diabetic and 300 non-diabetic patients who followed a LPD, with a personalized approach aimed at moderate protein restriction (0.6 g/day). Survival analysis was performed according to Kaplan–Meier, and multivariate analysis with Cox model. Diabetic versus non-diabetic patients were of similar age (median 70 years) and creatinine levels at the start of the diet (2.78 mg/dL vs. 2.80 mg/dL). There was higher prevalence of nephrotic proteinuria in diabetic patients (27.52% vs. 13.67%, p = 0.002) as well as comorbidity (median Charlson index 8 vs. 6 p = 0.002). Patient survival was lower in diabetic patients, but differences levelled off considering only cases with Charlson index > 7, the only relevant covariate in Cox analysis. Dialysis-free survival was superimposable in the setting of good compliance (Mitch formula: 0.47 g/kg/day in both groups): about 50% of the cases remained dialysis-free 2 years after the first finding of e-GFR (estimated glomerular filtration rate) < 15 mL/min, and 1 year after reaching e-GFR < 10 mL/min. In patients with type 2 diabetes, higher proteinuria was associated with mortality and initiation of dialysis. In conclusion, moderately restricted LPDs allow similar results in diabetic and non non-diabetic patients with similar comorbidity
Polymorphic post-transplant lymphoproliferative disorder in a gilt
N.A. (case report, no abstract
Synergism and negative interference during co-infection of tomato and Nicotiana benthamiana with two bipartite begomoviruses
In Brazil, at least eight begomoviruses including Tomato rugose mosaic virus (ToRMV) and Tomato yellow spot virus (ToYSV) infect tomatoes. ToYSV symptoms in tomato and Nicotiana benthamiana appear earlier and are more severe compared to those of ToRMV. We investigated the role of several factors in this differential adaptation. To analyze infection kinetics, a single leaf was inoculated and subsequently detached after different periods of time. Viral DNA accumulation was quantified in plants, viral replication was analyzed in protoplasts, and tissue tropism was determined by in situ hybridization. Results indicate that ToYSV establishes a systemic infection and reaches a higher concentration earlier than ToRMV in both hosts. ToRMV negatively interferes with ToYSV during the initial stages of infection, but once systemic infection is established this interference ceases. In N. benthamiana, ToYSV invades the mesophyll, while ToRMV is phloem-restricted. During dual infection in this host, ToYSV releases ToRMV from the phloem
Evaluation of the suberin presence in baby carrot, during the cooled conservation
[POR] Objetivou-se avaliar histoquimicamente a formação de periderme em minicenoura submetida à imersão em suspensão utilizada para revestimento comestÃvel à base de amido e quitosana. Cenouras cv. Esplanada colhidas aos 90 dias, processadas na forma de minicenouras, foram imersas em suspensão contendo 3 % de amido de milho (m/v), 1,5 % de quitosana (m/v), 2 % de glicerol (v/v) e 0,4 % de ácido acético glacial (v/v). Foram mantidas sob ventilação por três horas, embaladas em bandejas de polipropileno envoltas com filme de polivinilcloreto e mantidas a 5±1 ºC. Aos 0; 10; 25 e 30 dias, amostras foram fixadas, desidratadas, incluÃdas em historresina ou não, cortadas em micrótomo manual, coradas com sudan Red B, montadas em lâminas e fotografadas. Minicenouras que não foram imersas em suspensão e cenouras com periderme, serviram como controle. Nas minicenouras não imersas em suspensão, foi nÃtido o esbranquecimento na superficie a partir do terceiro dia de conservação. TodavÃa, pouca diferença foi observada na perda de massa fresca entre minicenouras imersas em suspensão e não imersas. Nas avaliações microscópicas, observouse acúmulo de paredes celulares oriundas de células colapsadas e desidratadas na superfÃcie de minicenoura com ou sem revestimento. Em minicenouras imersas na suspensão, foi observado, aos 30 dias, uma leve coloração avermelhada caracterÃstica de reação positiva com sudan Red B. TodavÃa, isso parece estar relacionado com componentes do revestimento, uma vez que não se observou reação positiva na região das paredes celulares, onde é caracterÃstico a presença de suberina, como foi evidenciado em cenouras intactas, com periderme. Portanto, não houve evidências para formação de suberina em minicenouras, com ou sem revestimento, durante o perÃodo de conservação estudado. Apoio financeiro: CAPES, CNPq e FAPEMIG. [ENG] Aimed to evaluate histoquimicamentley the presence of the periderm in baby carrot treated with edible antimicrobial coating base on a starch- chitosan matrix. Carrots of, Esplanada cultivar were harvested at 90 days after planting, were minimally processed in form of baby carrots and immersed in the suspension coating with on 3 % maiz starch (w/v) +2 % glycerol (v/v) + chitosan (1,5 %, w/v) and 0,4 % glacial acetic acid (v/v). All the samples were placed in extended polystyrene trays, wrapped in polyvinylchloride film and stored at 5±1 ºC for 12 or 15 days. At 0; 25 and 30 days, the sample were fixed, desidrated, historresin inclused our not, manual microtomo cuted, cored with red B sudan, monted in lamines and photographed. Baby carrot no immersed in suspension presented simptoms of white blush surface with 3 days of the conservation. Little difference was observed in the mass loss between immersed in suspension and not immersed baby carrots. In the microscopical evaluations, accumulation of cellular walls of colapsadas and dehydrated cells in the Surface of baby carrot with or without coating was observed. In immersed baby carrots in the suspension, it was observed, to the 30 days, a light colored coloration characteristic of positive reaction with sudan. This seems to be related with components of the coating, a time that did not observe positive reaction in the region of the cellular walls, where is characteristic the presence of suberina, as it was evidenced in unbroken carrots, with periderme. Therefore, it did not have evidences for formation of suberina in baby carrots, with or without coating, during the studied period of conservation.Os autores agradecem ao prof. Ricardo Henrique Silva Santos e estudantes pelo fornecimento da matéria-prima. À CAPES, CNPq e FAPEMIG pelo apoio financeiro
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