Comparative Analysis of Catalase Activity in Plants: Spectrophotometry and Native PAGE Approaches.

Catalase, a pivotal enzyme in plant antioxidative defense mechanisms, plays a crucial role in detoxifying hydrogen peroxide, a reactive oxygen species (ROS). In this chapter, a comparative analysis of catalase activity was conducted using two distinct methodologies: spectrophotometry and non-denaturing polyacrylamide gel electrophoresis (PAGE). The spectrophotometric approach allowed the quantification of catalase activity by measuring the breakdown rate of hydrogen peroxide, while native PAGE enabled the separation and visualization of catalase isozymes, based on their native molecular weight and charge characteristics, and specific staining assay. Both methods provide valuable insights into catalase activity, offering complementary information on the enzyme's functional diversity and distribution within different plant tissues. This study integrates different techniques, previously described, to comprehensively elucidate the role of catalase in plant metabolism. Furthermore, it provides the possibility of obtaining a holistic understanding of antioxidant defense mechanisms by considering both total activity and isoenzyme distribution of catalase enzyme.

Multifaceted roles of nitric oxide in tomato fruit ripening: NO-induced metabolic rewiring and consequences for fruit quality traits.

Nitric oxide (NO) has been implicated as part of the ripening regulatory network in fleshy fruits. However, very little is known about the simultaneous action of NO on the network of regulatory events and metabolic reactions behind ripening-related changes in fruit color, taste, aroma and nutritional value. Here, we performed an in-depth characterization of the concomitant changes in tomato (Solanum lycopersicum) fruit transcriptome and metabolome associated with the delayed-ripening phenotype caused by NO supplementation at the pre-climacteric stage. Approximately one-third of the fruit transcriptome was altered in response to NO, including a multilevel down-regulation of ripening regulatory genes, which in turn restricted the production and tissue sensitivity to ethylene. NO also repressed hydrogen peroxide-scavenging enzymes, intensifying nitro-oxidative stress and S-nitrosation and nitration events throughout ripening. Carotenoid, tocopherol, flavonoid and ascorbate biosynthesis were differentially affected by NO, resulting in overaccumulation of ascorbate (25%) and flavonoids (60%), and impaired lycopene production. In contrast, the biosynthesis of compounds related to tomato taste (sugars, organic acids, amino acids) and aroma (volatiles) was slightly affected by NO. Our findings indicate that NO triggers extensive transcriptional and metabolic rewiring at the early ripening stage, modifying tomato antioxidant composition with minimal impact on fruit taste and aroma.

Changes in the diet composition of fatty acids and fiber affect the lower gastrointestinal motility but have no impact on cardiovascular parameters: In vivo and in vitro studies.

BACKGROUND: Food and diet are central issues for proper functioning of the cardiovascular (CV) system and gastrointestinal (GI) tract. We hypothesize that different types of dietary FAs affect CV parameters as well as GI motor function and visceral sensitivity. METHODS: Male Wistar rats were fed with control diet (CTRL), diet supplemented with 7% soybean oil (SOY), SOY + 3.5% virgin coconut oil (COCO), and SOY + 3.5% evening primrose oil (EP) for 4 weeks. The content of insoluble fiber in CTRL was higher than in SOY, COCO, or EP. Body weight gain and food/water intake were measured. At day 28, biometric, biochemical, CV parameters, GI motor function (X-ray and colon bead expulsion test), and visceral sensitivity were evaluated. Changes in propulsive colonic activity were determined in vitro. The colon and adipose tissue were histologically studied; the number of mast cells (MCs) in the colon was calculated. RESULTS: SOY, COCO, and EP had increased body weight gain but decreased food intake vs CTRL. Water consumption, biometric, biochemical, and CV parameters were comparable between groups. SOY increased the sensitivity to colonic distention. All groups maintained regular propulsive neurogenic contractions; EP delayed colonic motility (P < 0.01). SOY, COCO, and EP displayed decreased size of the cecum, lower number and size of fecal pellets, and higher infiltration of MCs to the colon (P < 0.001). CONCLUSIONS AND INFERENCES: Dietary FAs supplementation and lower intake of insoluble fiber can induce changes in the motility of the lower GI tract, in vivo and in vitro, but CV function and visceral sensitivity are not generally affected.

Angiosarcoma de mama radioinducido / Radiotherapy-induced angiosarcoma of the breast

El angiosarcoma radioinducido de mama tras tratamiento quirúrgico conservador y radioterapia complementaria en una paciente con cáncer de mama es una entidad poco frecuente, de difícil diagnóstico y mal pronóstico. Se presenta el caso de una mujer de 71 años, con antecedentes personales de carcinoma ductal infiltrante de mama izquierda, a la que se practicó tumorectomía y linfadenectomía axilar (pT1cpN0M0), y recibió tratamiento adyuvante con radioterapia y hormonoterapia. 77 meses después del tratamiento, la paciente consultó al presentar una lesión cutánea en la mama izquierda. Tras valoración clínica, radiológica e histológica y con el diagnóstico de angiosarcoma de mama, se practicó mastectomía izquierda. Posteriormente no recibió tratamiento complementario

Radiotherapy-induced angiosarcoma of the breast after conservative surgical treatment and complementary radiotherapy in a patient with breast cancer is a rare condition, with both difficult diagnosis and poor prognosis. We present the case of a 71-year-old woman with a personal history of infiltrating ductal carcinoma of the left breast, who underwent tumorectomy and axillary lymphadenectomy (pT1cpN0M0), and received adjuvant treatment with radiotherapy and hormone therapy. 77 months after treatment, the patient consulted with a skin lesion on her left breast. After clinical, radiological and histological assessment and with the diagnosis of angiosarcoma of the breast, a mastectomy of her left breast was performed. The patient did not receive complementary treatment

Molecular Characterization and Stress Tolerance Evaluation of New Allotetraploid Somatic Hybrids Between Carrizo Citrange and Citrus macrophylla W. rootstocks.

Polyploidy is one of the main forces that drives the evolution of plants and provides great advantages for breeding. Somatic hybridization by protoplast fusion is used in citrus breeding programs. This method allows combining the whole parental genomes in a single genotype, adding complementary dominant characters, regardless of parental heterozygosity. It also contributes to surpass limitations imposed by reproductive biology and quickly generates progenies that combine the required traits. Two allotetraploid somatic hybrids recovered from the citrus rootstocks-Citrus macrophylla (CM) and Carrizo citrange (CC)-were characterized for morphology, genome composition using molecular markers (SNP, SSR, and InDel), and their tolerance to iron chlorosis, salinity, and Citrus tristeza virus (CTV). Both hybrids combine the whole parental genomes even though the loss of parental alleles was detected in most linkage groups. Mitochondrial genome was inherited from CM in both the hybrids, whereas recombination was observed for chloroplastic genome. Thus, somatic hybrids differ from each other in their genome composition, indicating that losses and rearrangements occurred during the fusion process. Both inherited the tolerance to stem pitting caused by CTV from CC, are tolerant to iron chlorosis such as CM, and have a higher tolerance to salinity than the sensitive CC. These hybrids have potential as improved rootstocks to grow citrus in areas with calcareous and saline soils where CTV is present, such as the Mediterranean region. The provided knowledge on the effects of somatic hybridization on the genome composition, anatomy, and physiology of citrus rootstocks will be key for breeding programs that aim to address current and future needs of the citrus industry.

Miming neurological syndromes improves medical student's long-term retention and delayed recall of neurology.

Basic examination and diagnostic skills in neurology are important for every graduating medical student. However, a majority of medical students consider neurology as complex and difficult to master. We evaluate the impact a learner-friendly, innovative simulation-based training programme has on long-term retention and delayed recall of neurological semiology amongst third-year medical students from the University Pierre et Marie Curie in Paris, France. The 2013 class received standard teaching in neurological semiology. The 2015 class who received the same standard teaching in neurological semiology were also invited to voluntarily participate in The Move, a mime-based role-play training programme of neurological semiology. During the Move, students were trained to simulate a patient with a neurological syndrome or the physician examining the patient. Students were evaluated with an assessment thirty months after their neurological rotation, including 15 questions to evaluate long-term retention of neurological semiology, and 10 to test background knowledge in general semiology. The semiology test was performed by 366/377 students from the 2013 class (standard education group) and by 272/391 students from the 2015 class, among which 186 participated in The Move (The Move group) and 86 did not (standard education group). The mean neurological semiology score was higher in the 2015 class compared to the 2013 class (p = 0.007) and remained so after adjustment for the general semiology performance (p = 0.003). The adjusted mean neurological semiology score was 1.21/15 points higher [95% CI 0.66, 1.75] in The Move group compared to the standard education group, corresponding to a 14% better ranking. The Move programme improves medical student's long-term retention and delayed recall of neurological semiology. This learner-friendly interactive teaching may in turn enhance clinical proficiency of future physicians in neurological semiology.

Effect of linseed supplementation and slaughter age on meat quality of grazing cross-bred Galician x Burguete foals.

BACKGROUND: The aim of this study was to assess the effect of finishing diet (control concentrate vs. linseed concentrate) and slaughter age (13 vs. 26 months) on meat and nutritional quality of foal meat. For this study, 46 foals from crossing Galicia Mountain x Burguete breeds were used. RESULTS: The obtained results showed that slaughter age had an influence on chemical composition and colour parameters. Foals slaughtered at the age of 13 months had lower content of intramuscular fat and higher cholesterol contents than those slaughtered at 26 months of age. Regarding colour parameters, older foals showed the highest values of redness and lowest myoglobin contents. Finishing diet had a low effect on the majority of parameters evaluated. Foals fed with linseed presented lower shear force values than those fed with control concentrate. Fatty acid and amino acid contents were hardly influenced by finishing diet, whereas slaughter age effect had a high impact on fatty acid profile. Older animals showed lowest SFA values and n-6/n-3 ratio. CONCLUSION: Older animals presented the best meat quality. Diet had low effect in meat quality and could be related to the short time during finishing diet was administered and the low amount of linseed in the experimental diet. © 2017 Society of Chemical Industry.

A randomized, controlled, double-blind, crossover trial of triheptanoin in alternating hemiplegia of childhood.

BACKGROUND: Based on the hypothesis of a brain energy deficit, we investigated the safety and efficacy of triheptanoin on paroxysmal episodes in patients with alternating hemiplegia of childhood due to ATP1A3 mutations. METHODS: We conducted a randomized, double-blind, placebo-controlled crossover study of triheptanoin, at a target dose corresponding to 30% of daily calorie intake, in ten patients with alternating hemiplegia of childhood due to ATP1A3 mutations. Each treatment period consisted of a 12-week fixed-dose phase, separated by a 4-week washout period. The primary outcome was the total number of paroxysmal events. Secondary outcomes included the number of paroxysmal motor-epileptic events; a composite score taking into account the number, severity and duration of paroxysmal events; interictal neurological manifestations; the clinical global impression-improvement scale (CGI-I); and safety parameters. The paired non-parametric Wilcoxon test was used to analyze treatment effects. RESULTS: In an intention-to-treat analysis, triheptanoin failed to reduce the total number of paroxysmal events (p = 0.646), including motor-epileptic events (p = 0.585), or the composite score (p = 0.059). CGI-I score did not differ between triheptanoin and placebo periods. Triheptanoin was well tolerated. CONCLUSIONS: Triheptanoin does not prevent paroxysmal events in Alternating hemiplegia of childhood. We show the feasibility of a randomized placebo-controlled trial in this setting. TRIAL REGISTRATION: The study has been registered with clinicaltrials.gov ( NCT002408354 ) the 03/24/2015.

Arsenic-induced stress activates sulfur metabolism in different organs of garlic (Allium sativum L.) plants accompanied by a general decline of the NADPH-generating systems in roots.

Arsenic (As) contamination is a major environmental problem which affects most living organisms from plants to animals. This metalloid poses a health risk for humans through its accumulation in crops and water. Using garlic (Allium sativum L.) plants as model crop exposed to 200µM arsenate, a comparative study among their main organs (roots and shoots) was made. The analysis of arsenic, glutathione (GSH), phytochelatins (PCs) and lipid peroxidation contents with the activities of antioxidant enzymes (catalase, superoxide dismutase, ascorbate-glutathione cycle), and the main components of the NADPH-generating system, including glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), NADP-malic enzyme (NADP-ME) and NADP-isocitrate dehydrogenase (NADP-ICDH) was carried out. Data showed a correlation among arsenic accumulation in the different organs, PCs content and the antioxidative response, with a general decline of the NADPH-generating systems in roots. Overall, our results demonstrate that there are clear connections between arsenic uptake, increase of their As-chelating capacity in roots and a decline of antioxidative enzyme activities (catalase and the ascorbate peroxidase) whose alteration provoked As-induced oxidative stress. Thus, the data suggest that roots act as barrier of arsenic mediated by a prominent sulfur metabolism which is characterized by the biosynthesis of high amount of PCs.

Asymmetric dimethylarginine (ADMA) elevation and arginase up-regulation contribute to endothelial dysfunction related to insulin resistance in rats and morbidly obese humans.

KEY POINTS: The presence of insulin resistance (IR) is determinant for endothelial dysfunction associated with obesity. Although recent studies have implicated the involvement of mitochondrial superoxide and inflammation in the defective nitric oxide (NO)-mediated responses and subsequent endothelial dysfunction in IR, other mechanisms could compromise this pathway. In the present study, we assessed the role of asymmetric dimethylarginine (ADMA) and arginase with respect to IR-induced impairment of endothelium-dependent vasodilatation in human morbid obesity and in a non-obese rat model of IR. We show that both increased ADMA and up-regulated arginase are determinant factors in the alteration of the l-arginine/NO pathway associated with IR in both models and also that acute treatment of arteries with arginase inhibitor or with l-arginine significantly alleviate endothelial dysfunction. These results help to expand our knowledge regarding the mechanisms of endothelial dysfunction that are related to obesity and IR and establish potential therapeutic targets for intervention. ABSTRACT: Insulin resistance (IR) is determinant for endothelial dysfunction in human obesity. Although we have previously reported the involvement of mitochondrial superoxide and inflammation, other mechanisms could compromise NO-mediated responses in IR. We evaluated the role of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA) and arginase with respect to IR-induced impairment of l-arginine/NO-mediated vasodilatation in human morbid obesity and in a non-obese rat model of IR. Bradykinin-induced vasodilatation was evaluated in microarteries derived from insulin-resistant morbidly obese (IR-MO) and non-insulin-resistant MO (NIR-MO) subjects. Defective endothelial vasodilatation in IR-MO was improved by l-arginine supplementation. Increased levels of ADMA were detected in serum and adipose tissue from IR-MO. Serum ADMA positively correlated with IR score and negatively with pD2 for bradykinin. Gene expression determination by RT-PCR revealed not only the decreased expression of ADMA degrading enzyme dimethylarginine dimethylaminohydrolase (DDAH)1/2 in IR-MO microarteries, but also increased expression of arginase-2. Arginase inhibition improved endothelial vasodilatation in IR-MO. Analysis of endothelial vasodilatation in a non-obese IR model (fructose-fed rat) confirmed an elevation of circulating and aortic ADMA concentrations, as well as reduced DDAH aortic content and increased aortic arginase activity in IR. Improvement of endothelial vasodilatation in IR rats by l-arginine supplementation and arginase inhibition provided functional corroboration. These results demonstrate that increased ADMA and up-regulated arginase contribute to endothelial dysfunction as determined by the presence of IR in human obesity, most probably by compromising arginine availability. The results provide novel insights regarding the mechanisms of endothelial dysfunction related to obesity and IR and establish potential therapeutic targets for intervention.

Bioremediation and toxicity determination of natural seawater polluted with weathered crude oil by salt-tolerant consortia in a SBR.

The aim of this research was to compare the bioremediation treatment of seawater polluted with two different concentrations of weathered crude oil (0.2 for experiment (a) and 1.14% for experiment (b), v/v) by salt-tolerant consortia enriched from the sludge of a refinery wastewater treatment facility, in a SBR. The use of a commercial bioremediation stimulant (S200) was also evaluated as an alternative to the traditional nitrogen and phosphorus supplement.

Reflexiones epistemologicas sobre la teoría, la práctica y la investigación en enfermería / Meditate epistemology on the theory, the practice and the nursing research

En este trabajo se aborda, desde la reflexión epistemologica, la teoría, la práctica y la investigación en enfermería, presentando las categorías analizadas por Reimer y Tripp. El objetivo del mismo es introducir al lector en el analisis reflexivo de la producción del conocimiento, como requisito basico para la ubicación de la enfermería como disciplina en la comunidad científica.AU

Reflexiones epistemologicas sobre la teoría, la práctica y la investigación en enfermería / Meditate epistemology on the theory, the practice and the nursing research

En este trabajo se aborda, desde la reflexión epistemologica, la teoría, la práctica y la investigación en enfermería, presentando las categorías analizadas por Reimer y Tripp. El objetivo del mismo es introducir al lector en el analisis reflexivo de la producción del conocimiento, como requisito basico para la ubicación de la enfermería como disciplina en la comunidad científica.