Different outcomes for transplant-eligible newly diagnosed multiple myeloma patients in Latin America according to the public versus private management: a GELAMM study.

The aim of this study was to describe clinical and survival characteristics of transplant-eligible multiple myeloma (MM) patients in Latin America (LA), with a special focus on differences between public and private healthcare facilities. We included 1293 patients diagnosed between 2010 and 2018. A great disparity in outcomes and survival between both groups was observed. Late diagnosis and low access to adequate frontline therapy and ASCT in public institutions probably explain these differences. Patients treated with novel drug induction protocols, followed by autologous stem cell transplantation (ASCT) and maintenance, have similar overall survival compared to that published internationally.

Biochemical and molecular approach of oxidative damage triggered by water stress and rewatering in sunflower seedlings of two inbred lines with different ability to tolerate water stress.

Water stress accelerates the generation of reactive oxygen species, which trigger a cascade of antioxidative defence mechanisms comprising enzymatic and nonenzymatic antioxidants. The aim of this study was to investigate the oxidative damage and the antioxidative defence systems in seedlings of the water stress-tolerant (B71) and the sensitive (B59) inbred lines of sunflower (Helianthus annuus L.) in response to water stress and rewatering. In addition, we characterised the transcriptomic profile associated with enzymatic antioxidative defence. An elevated electrolyte leakage in B59 indicated increased plasmatic membrane permeability, which correlated with greater sensitivity to water stress. In response to water stress, both lines showed an increase in malondialdehyde and H2O2 content but these increases were more noticeable in the sensitive line. In both lines, an increase in enzymatic activity (e.g. peroxidase and ascorbate peroxidase) was not sufficient to overcome the H2O2 accumulation triggered by water stress. Upon water stress, the overall expression level of genes associated with the enzymatic antioxidant system increased in B71 and decreased in B59, which showed downregulated levels of most genes in the shoots. The general profile of phenolic compounds was clearly different between organs and between inbred lines. The B59 line activated nonenzymatic antioxidant responses to counteract the oxidative stress caused by water stress. The tolerance of B71 to water stress could be associated with compensatory antioxidant mechanisms based on the expression of genes encoding enzyme components of the ascorbate-glutathione and redoxin cycles, which contributed to explaining, at least partly, the response of this line.

Effect of Arbuscular Mycorrhizal Colonization on Cadmium-Mediated Oxidative Stress in Glycine max (L.) Merr.

Cadmium is a heavy metal (HM) that inhibits plant growth and leads to death, causing great losses in yields, especially in Cd hyperaccumulator crops such as Glycine max (L.) Merr. (soybean), a worldwide economically important legume. Furthermore, Cd incorporation into the food chain is a health hazard. Oxidative stress (OS) is a plant response to abiotic and biotic stresses with an intracellular burst of reactive oxygen species (ROS) that causes damage to lipids, proteins, and DNA. The arbuscular mycorrhizal fungal (AMF) association is a plant strategy to cope with HM and to alleviate OS. Our aim was to evaluate the mitigation effects of mycorrhization with AMF Rhizophagus intraradices on soybean growth, nutrients, Cd accumulation, lipid peroxidation, and the activity of different antioxidant agents under Cd (0.7-1.2 mg kg-1 bioavailable Cd) induced OS. Our results suggest that glutathione may act as a signal molecule in a defense response to Cd-induced OS, and mycorrhization may avoid Cd-induced growth inhibition and reduce Cd accumulation in roots. It is discussed that R. intraradices mycorrhization would act as a signal, promoting the generation of a soybean cross tolerance response to Cd pollution, therefore evidencing the potential of this AMF association for bioremediation and encouragement of crop development, particularly because it is an interaction between a worldwide cultivated Cd hyperaccumulator plant and an AMF-HM-accumulator commonly present in soils.

Spatiotemporal variations in salicylic acid and hydrogen peroxide in sunflower seeds during transition from dormancy to germination.

Phytohormones and reactive oxygen species mediate processes such as germination and dormancy. The elucidation of the physiological and biochemical events implicated in the transition from dormancy to germination in different plant species such as sunflower becomes a topic of interest. In this study, we investigated the spatiotemporal variation of salicylic acid (SA), hydrogen peroxide (H2 O2 ) and the activity of two antioxidant enzymes (catalase, CAT - EC 1.11.1.6 and ascorbate peroxidase - EC 1.11.1.11) in embryonic axis and cotyledons of dry and imbibed seeds of dormant (B123) and non-dormant (B91) sunflower lines. The results showed that embryonic axis had higher level of SA and H2 O2 than cotyledons in both lines. In dry seeds, B123 embryo (embryonic axis + cotyledons) showed a higher SA content than B91. After dry storage at room temperature, SA decreased in B123 embryos to a value close to that registered in B91 embryos. B123 embryonic axis of dry seeds presented higher H2 O2 levels than B91. Dry storage led to an increase of H2 O2 levels and a decrease of CAT activity in B123 embryonic axis. During imbibition, B123 seeds stored for 33 days displayed an increase in SA level in the embryonic axis (3 h of imbibition) and this lower level correlated with a decrease in H2 O2 (6 h of imbibition). Thus, the embryo-imposed dormancy in B123 dry seeds was associated with high levels of SA and low H2 O2 , whereas the dormancy release was linked with SA decrease and increase of H2 O2 as a consequence of lower CAT activity.

Cadmium induces two waves of reactive oxygen species in Glycine max (L.) roots.

Cadmium (Cd) is a non-essential heavy metal that may be toxic or even lethal to plants as it can be easily taken up by the roots and loaded into the xylem to the leaves. Using soybean roots (Glycine max L.) DM 4800, we have analysed various parameters related to reactive oxygen metabolism and nitric oxide (NO) during a 6 day Cd exposure. A rise in H(2)O(2) and NO, and to a lesser extent O(2)(·-) content was observed after 6 h exposure with a concomitant increase in lipid peroxidation and carbonyl group content. Both oxidative markers were significantly reduced after 24 h. A second, higher wave of O(2)(·-) production was also observed after 72 h of exposure followed by a reduction until the end of the treatment. NOX and glicolate oxidase activity might be involved in the initial Cd-induced reactive oxygen species (ROS) production and it appears that other sources may also participate. The analysis of antioxidative enzymes showed an increase in glutathione-S-transferase activity and in transcript levels and activity of enzymes involved in the ascorbate-glutathione cycle and the NADPH-generating enzymes. These results suggest that soybean is able to respond rapidly to oxidative stress imposed by Cd by improving the availability of NADPH necessary for the ascorbate-glutathione cycle.