The effects of NaCl stress on the growth and photosynthetic characters of Ulmus pumila L. seedlings were investigated under sand culture condition. With increasing NaCl concentration, main stem height, branch number, leaf number, and leaf area declined, while Na+ content and the Na+/K+ ratio in both expanded and expanding leaves increased. Na+ content was significantly higher in expanded leaves than in those just expanding. Chlorophyll (Chl) a and Chl b contents declined as NaCl concentration increased. The net photosynthetic rate, intercellular CO2 concentration, stomatal conductance, and transpiration rate also declined, but stomatal limitation value increased as NaCl concentration increased. Both the maximal quantum yield of PSII photochemistry and the effective quantum yield of PSII photochemistry declined as NaCl concentration rose. These results suggest that the accumulation of Na+ in already expanded leaves might reduce damage to the expanding leaves and help U. pumila endure high salinity. The reduced photosynthesis in response to salt stress was mainly caused by stomatal limitation., Z. T. Feng, Y. Q. Deng, H. Fan, Q. J. Sun, N. Sui, B. S. Wang., and Obsahuje bibliografii
Polyurie se v neurointenzivní péči vyskytuje poměrně často a je spojena s rizikem vzniku vodní nebo sodné dysbalance. Polyurii způsobují dva základní mechanizmy: vodní nebo osmotická diuréza. Typickou vodní diurézou u akutního onemocnění mozku je centrální diabetes insipidus, u kterého ztráta čisté vody způsobuje hypernatremii. Osmotická diuréza se vyskytuje u syndromu cerebrálně podmíněné ztráty soli (cerebral salt wasting syndrome), kde natriuréza způsobuje hypoosmolální hyponatremii. Cílem neurointenzivní péče je prevence iatrogenních dysnatremií bezpečným managementem polyurií, který spočívá v diagnostice typu polyurie a odlišení kompenzační reakce organizmu na zvýšenou zátěž osmotických látek nebo tekutin od poruchy způsobené akutním poškozením mozku. V naší kazuistice prezentujeme 34letou pacientku se subarachnoidálním krvácením, u níž vznikla iatrogenní hypoosmolální hyponatremie, tzv. iatrogenní lékem způsobený SIADH (syndrom nepřiměřené sekrece antidiuretického hormonu, iatrogenic drug‑associated SIADH) v důsledku nesprávně podaného desmopresinu u polyurie s vodní diurézou., Polyuria is often seen in neurocritical care patients and can cause severe water and sodium imbalance. There are two major mechanisms causing the loss of water via the kidneys. The loss may be either due to osmotic or water diuresis. Central diabetes insipidus is a typical water diuresis, with free water losses causing hypernatremia in acute brain disease. Sodium diuresis occurs in cerebral salt wasting syndrome and causes hypoosmolal hyponatremia. One of the aims of neurocritical care is to prevent iatrogenic dysnatremias by careful management of polyuria. This requires correct diagnosis of the type of diuresis and differentiation of the possible cause – whether this is the organism’s compensatory response to higher fluid or osmotic agent intake or acute brain damage. We present a case of a 34‑year‑old female patient with subarachnoid hemorrhage and iatrogenic hypoosmolal hyponatremia, iatrogenic drug‑associated SIADH (syndrome of inappropriate secretion of antidiuretic hormone) caused by erroneous administration of desmopressine acetate in polyuria with free water diuresis., and V. Špatenková, P. Škrabálek
Physiological traits, which are positively associated with yield under salt-stress conditions, can be useful selection criteria in screening for salt tolerance. We examined whether chlorophyll (Chl) content can be used as screening criterion in wheat. Our study involved 5 wheat genotypes under both saline and nonsaline field conditions as well as in a sand-culture experiment. Salt stress reduced significantly biomass, grain yield, total Chl and both Chl a and b in all genotypes. In the sand-culture experiment, Chl accumulation was higher in PF70354/BOW, Ghods, and H499.71A/JUP genotypes at nonsaline control, moderate, and high salt concentrations, respectively. In the field experiment, genotype H499.71A/JUP belonged to those with the highest Chl density. The SPAD (Soil Plant Analysis Development) meter readings were linearly related to Chl content both in the sand-culture and in the field experiment. However, salt stress affected the calibration of SPAD meter. Therefore, separate Chl-SPAD equations were suggested for saline and nonsaline conditions. The correlation coefficients between the grain yield and SPAD were positive and significant both in the sand culture and in the field experiment. These findings suggested that SPAD readings could be used as a tool for rapid assessment of relative Chl content in wheat genotypes. It could be used for the indirect selection of high-yielding genotypes of wheat under saline condition in sand-culture and field experiments., A. Kiani-Pouya, F. Rasouli., and Obsahuje bibliografii
The present research was conducted to assess physiological responses of ‘Malas-e-Saveh’ (Malas) and ‘Shishe-Kab’ (Shishe) pomegranates to water of different salt content and electrical conductivity (1.05, 4.61, and 7.46 dS m-1). Both cultivars showed a reduced trunk length due to salinity. Relative water content and stomatal conductivity of both cultivars were significantly reduced under salt stress, but ion leakage increased. In both cultivars, total chlorophyll (Chl) and carbohydrates decreased with rise in salinity, while proline accumulation increased. With salinity increment, the Chl fluorescence parameters (maximum photochemical efficiency of PSII and effective quantum yield of PSII) declined significantly in both cultivars, with higher reduction observed in Shishe. Generally, more Na+ accumulated in shoots and more Cl- was observed in leaves. Cl- accumulation increased by salinity in leaves of Malas, but it was reduced in Shishe. The K+/Na+ ratio in leaves decreased in both cultivars by salinity increment. Malas was less affected by osmotic effects of NaCl, but it accumulated more Cl- in its leaves. Thus, Malas might be more affected by negative effects of salinity., M. Khayyat, A. Tehranifar, G. H. Davarynejad, M. H. Sayyari-Zahan., and Obsahuje bibliografii