Receptory glutaminianu u roślin

Badania prowadzone na pobudliwych plechach wątrobowca Conocephalum conicum wykazały, że podanie 5 mM roztworu glutaminianu (Glu) bądź glicyny (Gly) wywołuje serie potencjałów czynnościowych (AP), którym towarzyszy napływ wapnia do cytoplazmy pobudzonej komórki. Otrzymane wyniki są zgodne z istniejącą hipotezą że międzykomórkowy signalling oparty na aminokwasach jest obecny w królestwie roślin i zwierząt. Jak dotąd opublikowane dane eksperymentalne z równoległych pomiarów wewnątrzkom órkowego stężenia Ca"+ i poziomu potencjału transmem branowego izolowanych komórek liści (M eyerhoff et al. 2004, 2005) lub korzenia (Dennison i Spalding 2000) dotyczą głownie A rabidopsis thaliana, u której to rośliny zlokalizowano i sklonowano geny receptora kwasu glutaminowego (GLR). Nasze badania po raz pierwszy wykazały istnienie zależności między podaniem Glu a pobudzeniem u roślin niższych.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 dofinansowane zostało ze środków MNiSW w ramach działalności upowszechniającej naukę

Obserwacja długoterminowa u pacjentów z wszczepialnym kardiowerterem- -defibrylatorem i poddanych terapii resynchronizującej oraz bez niej

Introduction. An implantable cardioverter-defibrillator (ICD) with or without resynchronisation therapy (CRT-D) is an effective treatment in heart failure patients (pts.).  Materials and methods. We retrospectively analysed 60 patients (50/60; 83.33% male) with implanted ICD or CRT-D followed-up in the Cardiology Department between May 1995 and February 2019 who had undergone at least one device exchange.  Results. Women rarely received ICD, and especially ICD with CRT-D, compared to men [9/26 females in ICD and 1/24 in CRT-D group (p = 0.035) OR 8.31 95% CI (0.98–70.56)] and presented higher left ventricular ejection fraction (LVEF) (38.11 ± 12.74% vs 29.65 ± 12.63, p = 0.027). CRT-D in our patients was implanted mainly as primary prevention [22/25 vs 18/35 (p = 0.0726) OR 6.93 95% CI (1.75–27.43)] and in patients with a lower LVEF compared to the ICD- only patients [24.75 ± 8.98 vs 35.52 ± 13.55% (p = 0.001)]. Technical analysis of endocardial lead parameters at im- plantation and at the final follow-up revealed a decrease in impedance in cases of atrial, defibrillator and left-ventricular leads. In the ICD-only group, atrial impedance was 280.03 ± 335.3 vs 218.29 ± 229.48 ohm (p = 0.0018), and defi- brillator lead impedance was 768.66 ± 210.62 vs 507.03 ± 131.67 ohm (p &lt; 0.001) (at implantation vs final follow-up respectively). In the ICD plus CRT-D group, mean atrial lead impedance was 511.05 ± 271.30 vs 388.55 ± 231.75 ohm (p = 0.007), impedance of the defibrillator lead was 698.95 ± 165.45 vs 547.13 ± 385.24 ohm (p = 0.002), and impe- dance of the left-ventricular lead was 1,036.28 ± 337.34 vs 794.87 ± 274.99 ohm (p &lt; 0.001).  Conclusion. Women receive CRT-D therapy less often than men. CRT-D is implanted in pts. with lower LVEF and mainly as primary prevention. All endocardial leads impedance decreased with the passing of time. Wprowadzenie. Wszczepialny kardiowerter-defibrylator (ICD) z terapią resynchronizującą (CRT-D) oraz bez niej stanowi efektywny element leczenia u pacjentów z niewydolnością serca.  Metody i wyniki. Sześćdziesięciu pacjentów (50/60; 83,33% mężczyzn) pozostających pod opieką kliniki kardiologii w la- tach od maja 1995 roku do lutego 2019 roku z wszczepionym ICD/CRT-D, u których wykonano przynajmniej jedną wy- mianę urządzenia, poddano retrospektywnej analizie. Kobietom rzadziej wszczepieniu zarówno ICD, jak i CRT-D niż męż- czyznom (9/26 kobiet w grupie z ICD oraz 1/24 w grupie z CRT-D [p = 0,035], iloraz szans [OR] 8.31 95-proc. przedział ufności [CI] 0,98–70,56). Panie charakteryzowały się wyższą frakcją wyrzutową lewej komory (LVEF) (38,11 ± 12,74% v. 29,65 ± 12,63 [p = 0,027]). U opisywanych chorych CRT-D wszczepiano głównie w ramach w prewencji pierwotnej (22/25 v. 18/35 [p = 0,0726], OR 6,93 95% CI 1,75–27,43) oraz u pacjentów z niższą LVEF niż u osób z ICD (24,75 ± 8,98 v. 35,52 ± 13,55%; p = 0,001). Analiza parametrów technicznych elektrod endokawitarnych wykazała obniżenie oporności, gdy porównano parametry z dnia wszczepienia i ostatniej wizyty kontrolnej. W grupie z wszczepionym ICD oporność elektrod przedsionkowych wynosiła 280,03 ± 335,3 w porównaniu z 218,29 ± 229,48 omów (p = 0,0018), a elektrod defibrylujących 768,66 ± 210,62 w porównaniu z 507,03 ± 131,67 omów (p < 0,001) (dzień implantacji v. ostatnia kontrola). W grupie poddanych CRT-D średnia oporność elektrod przedsionkowych wynosiła 511,05 ± 271,30 w porównaniu z 388,55 ± 231,75 omów (p = 0,007), elektrod defibrylujących 698,95 ± 165,45 w porównaniu z 547,13 ± 385,24 omów (p = 0,002), a elektrod lewokomorowych 1036,28 ± 337,34 w porównaniu z 794,87 ± 274,99 omów (p < 0,001), gdy porównano dzień implantacji z dniem ostatniej kontroli.  Wnioski. Kobiety podlegają terapii resynchronizującej znacznie rzadziej niż mężczyźni. Ponadto CRT-D poddano pacjen- tów z niższą LVEF, głównie w ramach prewencji pierwotnej. Oporność wszystkich elektrod ulegała obniżeniu z upływa- jącym czasem.

Quite a few reasons for calling carnivores "the most wonderful plants in the world"

A plant is considered carnivorous if it receives any noticeable benefit from catching small animals. The morphological and physiological adaptations to carnivorous existence is most complex in plants, thanks to which carnivorous plants have been cited by Darwin as ‘the most wonderful plants in the world’. When considering the range of these adaptations, one realizes that the carnivory is a result of a multitude of different features. Scope: This review discusses a selection of relevant articles, culled from a wide array of research topics on plant carnivory, and focuses in particular on physiological processes associated with active trapping and digestion of prey. Carnivory offers the plants special advantages in habitats where nutrient supply is scarce. Counterbalancing costs are the investments in synthesis and the maintenance of trapping organs and hydrolysing enzymes. With the progress in genetic, molecular and microscopic techniques, we are well on the way to a full appreciation of various aspects of plant carnivory. Conclusions: Sufficiently complex to be of scientific interest and finite enough to allow conclusive appraisal, carnivorous plants can be viewed as unique models for the examination of rapid organ movements, plant excitability, enzyme secretion, nutrient absorption, food-web relationships, phylogenetic and intergeneric relationships or structural and mineral investment in carnivory

Genetic insights into resting heart rate and its role in cardiovascular disease

Resting heart rate is associated with cardiovascular diseases and mortality in observational and Mendelian randomization studies. The aims of this study are to extend the number of resting heart rate associated genetic variants and to obtain further insights in resting heart rate biology and its clinical consequences. A genome-wide meta-analysis of 100 studies in up to 835,465 individuals reveals 493 independent genetic variants in 352 loci, including 68 genetic variants outside previously identified resting heart rate associated loci. We prioritize 670 genes and in silico annotations point to their enrichment in cardiomyocytes and provide insights in their ECG signature. Two-sample Mendelian randomization analyses indicate that higher genetically predicted resting heart rate increases risk of dilated cardiomyopathy, but decreases risk of developing atrial fibrillation, ischemic stroke, and cardio-embolic stroke. We do not find evidence for a linear or non-linear genetic association between resting heart rate and all-cause mortality in contrast to our previous Mendelian randomization study. Systematic alteration of key differences between the current and previous Mendelian randomization study indicates that the most likely cause of the discrepancy between these studies arises from false positive findings in previous one-sample MR analyses caused by weak-instrument bias at lower P-value thresholds. The results extend our understanding of resting heart rate biology and give additional insights in its role in cardiovascular disease development

Osmotic and Salt Stresses Modulate Spontaneous and Glutamate-Induced Action Potentials and Distinguish between Growth and Circumnutation in Helianthus annuus Seedlings

Action potentials (APs), i.e., long-distance electrical signals, and circumnutations (CN), i.e., endogenous plant organ movements, are shaped by ion fluxes and content in excitable and motor tissues. The appearance of APs and CN as well as growth parameters in seedlings and 3-week old plants of Helianthus annuus treated with osmotic and salt stress (0–500 mOsm) were studied. Time-lapse photography and extracellular measurements of electrical potential changes were performed. The hypocotyl length was strongly reduced by the osmotic and salt stress. CN intensity declined due to the osmotic but not salt stress. The period of CN in mild salt stress was similar to the control (~164 min) and increased to more than 200 min in osmotic stress. In sunflower seedlings growing in a hydroponic medium, spontaneous APs (SAPs) propagating basipetally and acropetally with a velocity of 12–20 cm min−1 were observed. The number of SAPs increased 2–3 times (7–10 SAPs 24 h−1plant−1) in the mild salt stress (160 mOsm NaCl and KCl), compared to the control and strong salt stress (3–4 SAPs 24 h−1 plant−1 in the control and 300 mOsm KCl and NaCl). Glutamate-induced series of APs were inhibited in the strong salt stress-treated seedlings but not at the mild salt stress and osmotic stress. Additionally, in 3-week old plants, the injection of the hypo- or hyperosmotic solution at the base of the sunflower stem evoked series of APs (3–24 APs) transmitted along the stem. It has been shown that osmotic and salt stresses modulate differently hypocotyl growth and CN and have an effect on spontaneous and evoked APs in sunflower seedlings. We suggested that potassium, sodium, and chloride ions at stress concentrations in the nutrient medium modulate sunflower excitability and CN

Plant Tolerance to Drought Stress in the Presence of Supporting Bacteria and Fungi: An Efficient Strategy in Horticulture

Increasing temperature leads to intensive water evaporation, contributing to global warming and consequently leading to drought stress. These events are likely to trigger modifications in plant physiology and microbial functioning due to the altered availability of nutrients. Plants exposed to drought have developed different strategies to cope with stress by morphological, physiological, anatomical, and biochemical responses. First, visible changes influence plant biomass and consequently limit the yield of crops. The presented review was undertaken to discuss the impact of climate change with respect to drought stress and its impact on the performance of plants inoculated with plant growth-promoting microorganisms (PGPM). The main challenge for optimal performance of horticultural plants is the application of selected, beneficial microorganisms which actively support plants during drought stress. The most frequently described biochemical mechanisms for plant protection against drought by microorganisms are the production of phytohormones, antioxidants and xeroprotectants, and the induction of plant resistance. Rhizospheric or plant surface-colonizing (rhizoplane) and interior (endophytic) bacteria and fungi appear to be a suitable alternative for drought-stress management. Application of various biopreparations containing PGPM seems to provide hope for a relatively cheap, easy to apply and efficient way of alleviating drought stress in plants, with implications in productivity and food condition