N metabolism performance in Chenopodium quinoa subjected to drought or salt stress conditions.

Currently it is estimated that the 20% of total cultivated land is affected by salt. Besides, drought events will increase worldwide. These factors are affecting plant growth and crop production compromising food security. Within this context, quinoa (Chenopodium quinoa) is becoming an alternative pseudocereal for food supply due to its capacity to grow under harsh environmental conditions. Besides, it is being proposed as key model species to study the physiological processes that permit this tolerance, although how N metabolism responds has been barely studied. This paper addresses, on one hand, the response of quinoa's N metabolism (N uptake, translocation, reduction and assimilation) under the forthcoming climatic conditions and, on the other hand, the comparison of the effects of both stresses when plants have similar relative water content and photosynthetic rates. Under mild salt stress (120 and 240 mM NaCl) N assimilation is not affected, while the N uptake is favored. Under severe salt stress (500 mM NaCl), N uptake is reduced, decreasing leaf nitrate and protein concentration; nevertheless, leaf free amino acids are maintained -to perform osmotic adjustment-. N uptake rate is more affected under drought than under severe salt; furthermore, under severe salt stress, quinoa allocates more nitrogen to roots to finely regulate NO3- and Cl- uptake, while under drought it allocates more to leaves to ensure photosynthesis. These results indicate that quinoa's N metabolism is tolerant to drought and salt stress, although the strategies of this species for coping with the aforementioned stresses are different.

Tissue damage markers after a spinal manipulation in healthy subjects: a preliminary report of a randomized controlled trial.

Spinal manipulation (SM) is a manual therapy technique frequently applied to treat musculoskeletal disorders because of its analgesic effects. It is defined by a manual procedure involving a directed impulse to move a joint past its physiologic range of movement (ROM). In this sense, to exceed the physiologic ROM of a joint could trigger tissue damage, which might represent an adverse effect associated with spinal manipulation. The present work tries to explore the presence of tissue damage associated with SM through the damage markers analysis. Thirty healthy subjects recruited at the University of Jaén were submitted to a placebo SM (control group; n = 10), a single lower cervical manipulation (cervical group; n = 10), and a thoracic manipulation (n = 10). Before the intervention, blood samples were extracted and centrifuged to obtain plasma and serum. The procedure was repeated right after the intervention and two hours after the intervention. Tissue damage markers creatine phosphokinase (CPK), lactate dehydrogenase (LDH), C-reactive protein (CRP), troponin-I, myoglobin, neuron-specific enolase (NSE), and aldolase were determined in samples. Statistical analysis was performed through a 3 × 3 mixed-model ANOVA. Neither cervical manipulation nor thoracic manipulation did produce significant changes in the CPK, LDH, CRP, troponin-I, myoglobin, NSE, or aldolase blood levels. Our data suggest that the mechanical strain produced by SM seems to be innocuous to the joints and surrounding tissues in healthy subjects.