Genetic predispositions may influence geographical and interethnic differences in COVID-19 prevalence and mortality in affected populations. Of the many genes implicated in COVID-19 progression, a substantial number have no direct functional link on virus transfer/viability or on the host immune system. To address this knowledge deficit, a large number of in silico studies have recently been published. However, the results of these studies often contradict the findings of studies involving real patients. For example, the ACE2 has been shown to play an important role in regulating coronavirus entry into cells, but none of its variations have been directly associated with COVID19 susceptibility or severity. Consistently was reported that increased risk of COVID-19 is associated with blood group A and with the APOE4 allele. Among other genes with potential impacts are the genes for CCR5, IL-10, CD14, TMPRSS2 and angiotensinconverting enzyme. Variants within the protein-coding genes OAS1 and LZTFL1 (transferred to the human genome from Neanderthals) are understood to be among the strongest predictors of disease severity. The intensive research efforts have helped to identify the genes and polymorphisms that contribute to SARS-CoV-2 infection and COVID-19 severity.
Plant essential oils (EOs) have been reported to have health benefit properties and their preventive and therapeutic use in animals is expected to increase in the future. We evaluated the influence of five essential oils obtained from plant species which are known to have positive antimicrobial, antioxidative and anti-inflammatory effects – sage EO from Salvia officinalis L. (Lamiaceae), oregano EO from Origanum vulgare L. (Lamiaceae), thyme EO from Thymus vulgaris L. (Lamiaceae), clove EO from Syzygium aromaticum L. (Myrtaceae) and cinnamon EO from Cinnamomum zeylanicum Blume (Lauraceae) on the growth and development of mouse preimplantation embryos in vivo. Essential oils were added to commercial diet at concentrations of 0.25 % for sage EO, thyme EO, clove EO, cinnamon EO and 0.1 % for oregano EO, and fed to ICR female mice for 2 weeks ad libitum. Females were then mated with males of the same strain. Embryos obtained on Day 4 of pregnancy at the blastocyst stage were stained by morphological triple staining (Hoechst, PI, Calcein-AM) and evaluated using fluorescent microscopy. The effects of essential oils were estimated by the viability of embryos, number of nuclei and distribution of embryos according to nucleus number. Cinnamon EO significantly decreased the number of nuclei and the distribution of embryos according to nucleus number was significantly altered. Sage EO negatively influenced the distribution of embryos according to nucleus number. Clove and oregano EOs induced a significantly increased rate of cell death. Only thyme EO had no detectable effects on embryo development. In conclusion, none of the essential oils had any positive effect on embryo development, but some of them reduced the number of cells and increased the incidence of cell death., M. Domaracký, P. Rehák, Š. Juhás, J. Koppel., and Obsahuje bibliografii a bibliografické odkazy
An important mechanism underlying cochlear hair cell (HC) susceptibility to hypoxia/ischemia is the influx of Ca2+. Two main ATP-dependent mechanisms contribute to maintaining low Ca2+ levels: uptake of Ca2+ into intracellular stores via smooth endoplasmic reticulum calcium ATPase (SERCA) and extrusion of Ca2+ via plasma membrane calcium ATPase (PMCA). The effects of the SERCA inhibitors thapsigargin (10 nM-10 μM) and cyclopiazonic acid (CPA; 10-50 μM) and of the PMCA blockers eosin (1.5-10 μM) and o-vanadate (1-5 mM) on inner and outer hair cells (IHCs/OHCs) were examined in normoxia and ischemia using an in vitro model of the newborn rat cochlea. Exposure of the cultures to ischemia resulted in a significant loss of HCs. Thapsigargin and CPA had no effect. Eosin decreased the numbers of IHCs and OHCs by up to 25 % in normoxia and significantly aggravated the ischemia-induced damage to IHCs at 5 and 10 μM and to OHCs at 10 μM. o-Vanadate had no effect on IHC and OHC counts in normoxia, but aggravated the ischemia-induced HC loss in a dose-dependent manner. The effects of eosin and o-vanadate indicate that PMCA has an important role to play in protecting the HCs from ischemic cell death., N. Amarjargal, B. Mazurek, H. Haupt, N. Andeeva, J. Fuchs, J. Gross., and Obsahuje bibliografii a bibliografické odkazy
The effects of exposing winter-grown tomato {Lycopersicon esculentum L.) to various sunlight irradiances and CO2 concentrations, on dark respiration (Ro), night respiration (/?},}), net photosynthetic' rate (P^), dry matter production (DMP), yield earliness and yield amount were studied. Plants were grown in greenhouses under controlled temperatures and exposed to: fiill (FS) oř half (HS) sunlight irradiance in combination with atmospheric (A) oř enriched (E) concentrations of 300-330 or 1400-1500 g(C02) m'^, respectively. The of intact leaves at noontime reached 10.7, 15.2, 5.9 and 9.6 pmol(C02) m-2 s-i in treatments of FSA, FSE, HSA and HSE, respectively. The irradiances on the upper leaf surface during the measurements ranged between 160-190 and 450-550 pmol s'^ in the HS and FS treatments, respectively. of leaves which were kept in darkness following the measurement amved at efflux of 2.6, 2.5, 1.4 and 1.4 pmol(C02) m‘2 s'* while their Pn G^etween 20:00 and 24:00) reached values of 0.9, 1.3, 0.8 and 0.8 pmol(C02) treatments of FSA, FSE, HSA and HSE, respectively. Elevating the CO2 concentration from 300 to 1500 g m'^ increased P^ by 16, 28, 30 and 46 % under an irradiance of 160 pmol m‘2 s'*, and 19, 34, 59 and 44 % under irradiance of 320 pmol m-2 s'* in the FSA, FSE, HSA and HSE treatments, respectively. Increasing the measurement irradiance from 160 to 320 pmol m'2 s'* enhanced P^ by 69, 78, 23 and 49 % in an atmosphere of 300 g m-^ CO2, and by 73, 84, 49 and 47 % in an atmosphere of 1500 g m-^ CO2, in the FSA, FSE, HSA and HSE treatments, respectively. DMP was strongly influenced by the different environmental conditions and the total dry matter accumulation in the shoot per plant during 145 d reached 580, 347, 398 and 235 g in the FSA, FSE, HSA and HSE treatments, respectively. CO2 emichment promoted early yield under both full and partial sunlight irradiance. The HSE treatment led to earlier yield harvesting than the FSA and HSA treatments. The yield of the seven first trusses reached 6.8, 4.6, 5.7 and 3.2 kg per plant in the FSA, FSE, HSA and HSE treatments, respectively. Some increase in fruit fresh matter and diameter of fruits was detected in the C02-enrichéd treatments as compared to the non-enriched ones. Thus the combination of moderate shading and CO2 enrichment might provide a more productive option for winter- grown tomatoes in regions of subtropical climate, even in the winter, than the conventional management of aerated greenhouses without CO2 enrichment which are exposed to fiill sunlight.
The effects of shoot girdling on stomatal conductance (gs), leaf photosynthesis (PN), concentrations of carbohydrates, nitrogen and chlorophyll (Chl) in leaves, areal leaf mass (ALM), the diameter and length of shoots, and bud abscission in pistachio were investigated. Girdling individual shoots at the base of the current year’s shoot (girdle I), separating inflorescent buds on the terminal current year’s shoot from the developing fruits on the previous year’s shoot, reduced inflorescent bud abscission by 70% in comparison to nongirdled controls. Girdle I significantly reduced concentrations of nitrogen in leaves but increased those of nonstructural carbohydrates particularly of starch. Shoot diameter increased by 13.1% and 26.4% at 33 and 81 days after girdling (DAG), respectively, compared to 1% and 3.4% in the control, respectively. Both the leaf dry mass/fresh mass ratio and ALM were increased significantly by girdle I from 12 DAG. The concentrations of Chl a, Chl b, Chl (a+b), as well as the ratio of Chl a/b, all decreased with girdle I. The greatest negative effect of girdle I was on gs and PN. PN was reduced by 55% of its initial value and was 44% less than in the control leaves at 10 DAG, and fell to approximately 30% that of the control from 21 DAG. In contrast, girdling at the base of one-year-old shoots (girdle II), thus not separating fruits from the inflorescent buds, did not significantly affect gs or PN. The effect of girdling on PN and the possible factors that are involved in the reduction of photosynthesis in pistachio are discussed., S. N. Vemmos, A. Papagiannopoulou, S. Coward., and Obsahuje bibliografii
We examined the effects of weight loss induced by diet-orlistat (DO) and diet-orlistat combined with exercise (DOE) on maximal work rate production (Wmax) capacity in obese patients. Total of 24 obese patients were involved in this study. Twelve of them were subjected to DO therapy only and the remaining 12 patients participated in a regular aerobic exercise-training program in addition to DO therapy (DOE). Each patient performed two incremental ramp exercise tests up to exhaustion using an electromagnetically-braked cycle ergometer: one at the onset and one at the end of the 4th week. DOE therapy caused a significant decrease in total body weight: 101.5±17.4 kg (basal) vs 96.3±17.3 kg (4 wk) associated with a significant decrease in body fat mass: 45.0±10.5 kg (basal) vs 40.9±9.8 kg (4 wk). DO therapy also resulted in a significant decrease of total body weight 94.9±14.9 kg (basal) vs 91.6±13.5 kg (4 wk) associated with small but significant decreases in body fat mass: 37.7±5.6 kg (basal) to 36.0±6.2 kg (4 wk). Weight reduction achieved during DO therapy was not associated with increased Wmax capacity: 106±32 W (basal) vs 106±33 W (4 wk), while DOE therapy resulted in a markedly increased Wmax capacity: 109±39 W (basal) vs 138±30 W (4 wk). DO therapy combined with aerobic exercise training resulted in a significant reduction of fat mass tissue and markedly improved the aerobic fitness and Wmax capacities of obese patients. Considering this improvement within such a short period, physicians should consider applying an aerobic exercise-training program to sedentary obese patients for improving their physical fitness and thereby reduce the negative outcomes of obesity.
The effects of simulated acid rain on gas exchange, chlorophyll fluorescence, and anti-oxidative enzyme activity in cucumber seedlings (Cucumis sativus L. cv. Jingchun No. 4) were investigated. Acid rain significantly reduced net photosynthetic rate and mainly non-stomatal factors contributed to the decrease of photosynthesis during the experimental period. The reduced photosynthesis was associated with a decreased maximal photochemical efficiency (Fv/Fm) and the average quantum yield of the photosystem 2 (PS2) reaction centres (ΦPS2). Meanwhile, acid rain significantly increased the activities of guaiacol peroxidase (GPX) and superoxide dismutase (SOD), but decreased the activity of catalase (CAT) together with an increased content of malonyldialdehyde (MDA), Hence the changes in photosynthesis in acid rain treatment might be a secondary effect of acidity damage probably due to lipid peroxidation of lipids and proteins in thylakoid membrane rather than direct effect on PS2 reaction centre. and Jing-Quan Yu, Su-Feng Ye, Li-Feng Huang.
Crop plants in Closed Ecological Life Support Systems (CELSS), for future extended manned space missions, might use for photosynthesis natural sunlight rather than an artificial irradiation. In a low earth orbit (LEO: 300-600 km) space station CELSS, these plants would have to deal with very short light/dark cycles. As a result of the 90 min revolution period of the station around the earth, they would be subjected to approximately 60 min sunlight followed by 30 min darkness in the earth's shade. These orbital light/dark cycles were simulated in growth chambers, which was accompanied by control experiments under long-day conditions (16/8 h light/dark). In Phaseolus mungo L., Glycine max L. and Sorghum bicolor L. the net C02-uptake (PN) and stomatal conductance (gs), as well as 02-production and quantum yield (QY) were measured. P. mungo grown under orbital cycles was strongly affected by slow induction of photosynthesis and stomatal limitation, resulting in the photodestruction of pigment systems and leaf chlorosis. Stomata of G. max opened faster upon onset of irradiation, which resulted in a sufficient C02-supply to prevent photoinhibition. Stomata of S. bicolor opened very rapidly, and Pn resumed steady-state similar to that before the dark break, within the first minutes of the irradiation, thus utilizing the major part of the 60 min "day" for net carbon gain. These findings were supported by QY measurements of oxygen evolution. Strongly decreased QY in P. mungo compared to long-day grown plants indicated destruction in light-harvesting pigments and electron transport chains. No reduction in QY was observed in G. max and S. bicolor.
Kupffer cells (KC), resident macrophages of the liver, have been strongly implicated in lipopolysaccharide (LPS)-induced liver graft injury. However, our recent study showed that sizofiran (schizophyllan glucan) (SPG), which activates KC, did not influence cold ischemia-reperfusion liver injury of LPS-exposed rats. Here we investigated some mechanisms by which SPG does not aggravate LPS-enhanced cold ischemia-reperfusion rat liver injury. Control and SPG-treated rats were exposed to LPS for 2 h prior to hepatectomy. The livers were cold-preserved in University of Wisconsin solution followed by reperfusion with Krebs-Henseleit buffer. We found that SPG dramatically inhibited LPS-induced increases of tumor necrosis factor-α (TNF-α) in the plasma and bile in vivo. Moreover, LPS-induced TNF- release into the washout solution after cold ischemia was also abrogated by SPG pretreatment. However, SPG increased TNF-α release into the perfusate after reperfusion. On the other hand, SPG completely abolished expression of c-myc protooncogene, which is known to sensitize cells to TNF-α cytotoxicity. In conclusion, inhibition of both TNF-α release after LPS challenge and c-myc expression may explain why activation of KC with SPG does not aggravate endotoxin-enhanced cold ischemia-reperfusion liver injury.
Biochars, depending on the types of feedstocks and technological conditions of pyrolysis, can vary significantly in their properties and, therefore, it is difficult to predict biochar-induced effects on nitrous oxide (N2O) emissions from various soils, their physical properties and water availability. The objectives of this study were (1) to quantify effects of slow pyrolysis biochar (BC) and fast pyrolysis biochar (PYRO) on physical and hydro-physical properties of sandy soil (Haplic Arenosol) and clayey loam soil (Gleyic Fluvisol), and (2) to assess corresponding N2O emissions from these two soils. The study included a 63-day long laboratory investigation. Two doses of BC or PYRO (15 t ha–1 and 30 t ha–1) were applied to the soils in combination or without nitrogen fertilizer (NH4NO3, 90 kg N ha–1). The obtained results have shown a significant decrease in the bulk density of sandy soil after it was amended with either rate of BC or PYRO. Water retention capacity of the soils in all the treatments with BC or PYRO increased considerably although no changes was found in the soil water-filled pore space (WFPS) which was higher than 60%. BC was increasing N2O emission rates from the sandy soil treated with N fertilizer, and reducing N2O emission rates from the clayey loam soil treated with N fertilizer. PYRO was more efficient and was reducing N2O emissions from both fertilized soils, but for the sandy soil the reduction was statistically significant only at higher dose (30 t ha–1) of the biochar.