Is DNA methylation modulated by wounding-induced oxidative burst in maize?

Plants respond to environmental changes by modifying gene expression. One of the mechanisms regulating gene expression is methylation of cytosine to 5-methylcytosine (m5C) which modulates gene expression by changing chromatin structure. Methylation/demethylation processes affect genes that are controlled upon environmental stresses. Here, on account of the regulatory role of m5C, we evaluate the content of m5C in DNA from normal and wound-damaged maize leaves. Wounding leads to a transient decrease of the global DNA methylation level ca 20-30% 1 hour after the treatment followed by a return to the initial level within the next hours. Similar results were obtained using of radio-labelled nucleotides separated by Thin Layer Chromatography (TLC) or using m5C-specific Enzyme-Linked Immunosorbent Assay (ELISA). Wounding induced in maize leaves a two-step oxidative stress, an early one just after wounding and the second two hours later. It coincides with the transient changes of the cytosine methylation level. In the stress-inducible maize calcium-dependent protein kinase ZmCPK11 gene wounding transiently reduced methylation of cytosines 100 and 126 in the first exon

Phosphorylation of maize eif5a by ck2: identification of phosphorylated residue and influence on intracellular localization of eif5a.

Maize eukaryotic translation initiation factor 5A (ZmeIF5A) co-purifies with catalytic subunit of protein kinase CK2 and is phosphorylated by this enzyme. Phosphorylated ZmeIF5A was also identified after separation of maize leaf proteins by two-dimensional electrophoresis. Multiple sequence alignment of eIF5A proteins showed that in monocots, in contrast to other eukaryotes, there are two serine/threonine residues that could potentially be phosphorylated by CK2. To identify the phosphorylation site(s) of ZmeIF5A, the serine residues potentially phosphorylated by CK2 were mutated. ZmeIF5A and its mutated variants Ser2Ala and Ser4Ala were expressed in E. coli and purified. Of these recombinant proteins, only ZmeIF5ASer2Ala was not phosphorylated by maize CK2. Also, Arabidopsis thaliana and Saccharomyces cerevisiae eIF5A Ser2Ala mutants were not phosphorylated despite effective phosphorylation of wild-type variants. A newly developed method exploiting the specificity of thrombin cleavage was used to confirm that Ser2 in ZmeIF5A is indeed phosphorylated. To find a role of the Ser2 phosphorylation, ZmeIF5A and its variants mutated at Ser2 (Ser2Ala and Ser2Asp) were transiently expressed in maize protoplasts. The expressed fluorescence labeled proteins were visualized by confocal microscopy. While wild-type ZmeIF5A and its Ser2Ala variant were distributed evenly between the nucleus and the cytoplasm, the variant with Ser2 replaced by aspartic acid, which mimics a phosphorylated serine, was sequestered in the nucleus. These results suggests that phosphorylation of Ser2 plays a role in the regulation of nucleocytoplasmic shuttling of eIF5A in plant cells

Motives and Barriers in the Field of Cooperation Between Companies. Research Outcomes Based on the Polish Engineering Industry

Polish firms need to improve their performance in order to be more competitive internationally. As theoretical concepts of firm international competitiveness underline the importance of external sources of competitive advantage, empirical studies on firms cooperation may bring significant insight into this field. This paper presents theoretical foundations of firms' motives to form business partnerships and barriers to partnership relations. It is based on results of the study on cooperation of 155 Polish firms from the engineering sector

Smoking and Smoking Cessation in the Risk for Fetal Growth Restriction and Low Birth Weight and Additive Effect of Maternal Obesity

Many studies have shown that neonates of smoking mothers have a lower birth weight, but several issues remain poorly studied, e.g., the effects of giving up smoking or the combined effects of smoking and maternal obesity. Therefore, we evaluated a prospective cohort of 912 mothers in a single pregnancy, recruited in Poland, in 2015−2016. In the cohort, we recorded 72 (7.9%) newborns with birth weight <10th percentile, 21 (2.3%) fetal growth restriction (FGR) cases, and 60 (6.6%) low birth weight (LBW, <2500 g) newborns. In the cohort, 168 (18.4%) women smoked before pregnancy; the mean number of cigarettes/day was 10.8 (1–30), and the mean number of years of cigarette smoking was 8.5 (1–25). Among smokers, 57 (6.3%) women smoked in the first trimester. Adjusted odds ratio (AOR) of newborn outcomes (with 95% confidence intervals, CI) was calculated in multi-dimensional logistic regressions. Compared to participants who had never smoked, smoking before pregnancy was associated with a higher odds ratio of birth weight <10th percentile (AOR = 1.93, CI: 1.08–3.44, p = 0.027), but the result for LBW (AOR = 2.76, CI: 1.05–7.26, p = 0.039) and FGR (AOR = 1.13, CI: 0.38–3.36, p = 0.822) had the wider confidence interval or was insignificant. Effects of smoking cessation before pregnancy were statistically insignificant for the studied outcomes. Smoking in the first trimester was associated with a higher risk of birth weight <10th percentile (AOR = 4.68, CI: 2.28–9.62, p < 0.001), LBW (AOR = 6.42, CI: 1.84–22.36, p = 0.004), and FGR (AOR = 3.60, CI: 0.96–13.49, p = 0.057). Smoking cessation in the second/third trimester was associated with a higher odds ratio of birth weight <10th percentile (AOR = 4.54, CI: 1.58–13.02, p = 0.005), FGR (AOR = 3.36, CI: 0.6–18.74, p = 0.167), and LBW (AOR = 2.14, CI: 0.62–7.36), p = 0.229), to a similar degree to smoking in the first trimester. The odds ratios were higher in the subgroup of pre-pregnancy body mass index ≥25 kg/m2 for the risk of birth weight <10th percentile (AOR = 6.39, CI: 2.01–20.34, p = 0.002) and FGR (AOR = 6.25, CI: 0.86–45.59, p = 0.071). The length of cigarette smoking time was also the risk factor for studied outcomes. Conclusions: Smoking in the first trimester increased the studied risks, and the coexistence of excessive maternal weight increased the effects. Smoking cessation during the second/third trimester did not have a protective effect

Sprawność innowacyjna zagranicznych spółek zależnych w gospodarce po transformacji systemowej: wyniki dla Polski

The host country environment is an important source of knowledge for multinational enterprises (MNEs). The resources and competencies of MNEs’ foreign subsidiaries (FS) as well as internal and external relationships are perceived to be critically important for their performance. This study intends to fill a cognitive gap in the understanding of factors influencing the innovation performance of FS established in Poland. FS innovation performance is explained by their resourcebased specific advantages, internal embeddedness in the corporate network, external embeddedness, and by interactions between their systemic power and autonomy. The analysis is based on a 2018 survey of 436 manufacturing FS in Poland. The ordinary least squares (OLS) regression model was applied, along with three quantile regression equations to provide additional layers of detail. We observed a positive influence of FS’ own assets on innovation performance, especially if coupled with their deep internal embeddedness. The study also found a positive influence of internal embeddedness on innovation performance enhanced for high/medium-high-tech firms if coinciding with strong resource-based specific advantages. Another finding was that the external embeddedness of FS had a positive effect on their innovation performance. Besides, the positive influence of systemic power on innovation performance was only revealed for high/medium-high-tech FS, while the subsidiaries’ autonomy showed no significant influence on their innovation performance.Środowisko kraju goszczącego jest ważnym źródłem wiedzy dla przedsiębiorstw międzynarodowych. Zasoby i kompetencje filii zagranicznych (FZ) przedsiębiorstw międzynarodowych, a także ich relacje wewnętrzne i zewnętrzne są postrzegane jako krytyczne dla ich wyników ekonomicznych. Niniejsze opracowanie ma na celu wypełnienie luki poznawczej dotyczącej czynników wpływających na sprawność innowacyjną FZ utworzonych w Polsce. Sprawność innowacyjną FZ tłumaczy się ich przewagami opartymi na własnych zasobach: zakorzenieniem w wewnętrznej sieci korporacyjnej, zakorzenieniem zewnętrznym (w relacjach z niezależnymi partnerami) oraz poprzez interakcje między siłą systemową i autonomią FZ. Analiza opiera się na wynikach badania przeprowadzonego w 2018 r. w 436 FZ zlokalizowanych w Polsce. Zastosowano model OLS (metoda najmniejszych kwadratów) oraz trzy równania regresji kwantylowej, dostarczające bardziej szczegółowych wyników. Zaobserwowano: pozytywny wpływ zasobów własnych filii na ich sprawność innowacyjną, zwłaszcza w połączeniu z ich silnym wewnętrznym zakorzenieniem; pozytywny wpływ wewnętrznego zakorzenienia na innowacyjność, silniejszy wśród FZ w branżach wysokiej/średniowysokiej techniki, w połączeniu z przewagami opartymi na zasobach; pozytywny wpływ zewnętrznego zakorzenienia FZ na sprawność innowacyjną. Poza tym udowodniono: pozytywny wpływ siły systemowej na sprawność innowacyjną, ale tylko w przypadku FZ z branż wysokiej/średniowysokiej techniki. Nie zaobserwowano znaczącego wpływu autonomii FZ na ich wyniki innowacyjne

A Successful Outcome of Veno-Venous Extracorporeal Membrane Oxygenation in Obese Patients with Respiratory Failure in the Course of COVID-19: A Report of Two Cases

The use of extracorporeal membrane oxygenation (ECMO) in patients with respiratory failure in the course of COVID-19 indicates its limited efficacy and high mortality rates. It seems that one of the conditions for the success of veno-venous ECMO (VV ECMO) in obese patients with COVID-19 is the correct qualification and rapid implementation of this method. We present two cases of obese patients with acute respiratory distress syndrome (ARDS) as a result of SARS-CoV-2 infection with the successful use of ECMO. Two 41-year-old obese patients (Case 1: BMI 31.5 kg/m2 and Case 2: 44.5 kg/m2), with pneumonia and severe respiratory failure in the course of COVID-19, underwent ECMO therapy. The Extracorporeal Life Support Organization (ELSO) guidelines were used to qualify the patients. Due to the persistence of PaO2/FiO2 rate <80 for 6 h, a decision was made to implement VV ECMO. Both patients were discharged from the intensive care unit (Case 1: on day 35; Case 2: on day 22). Rapid implementation of VV ECMO in middle-aged, obese patients with ARDS in the course of COVID-19 showed a positive outcome

Netrin-1 and semaphorin 3A predict the development of acute kidney injury in liver transplant patients.

Acute kidney injury (AKI) is a serious complication after liver transplantation. Currently there are no validated biomarkers available for early diagnosis of AKI. The current study was carried out to determine the usefulness of the recently identified biomarkers netrin-1 and semaphorin 3A in predicting AKI in liver transplant patients. A total of 63 patients' samples were collected and analyzed. AKI was detected at 48 hours after liver transplantation using serum creatinine as a marker. In contrast, urine netrin-1 (897.8 ± 112.4 pg/mg creatinine), semaphorin 3A (847.9 ± 93.3 pg/mg creatinine) and NGAL (2172.2 ± 378.1 ng/mg creatinine) levels were increased significantly and peaked at 2 hours after liver transplantation but were no longer significantly elevated at 6 hours after transplantation. The predictive power of netrin-1, as demonstrated by the area under the receiver-operating characteristic curve for diagnosis of AKI at 2, 6, and 24 hours after liver transplantation was 0.66, 0.57 and 0.59, respectively. The area under the curve for diagnosis of AKI was 0.63 and 0.65 for semaphorin 3A and NGAL at 2 hr respectively. Combined analysis of two or more biomarkers for simultaneous occurrence in urine did not improve the AUC for the prediction of AKI whereas the AUC was improved significantly (0.732) only when at least 1 of the 3 biomarkers in urine was positive for predicting AKI. Adjusting for BMI, all three biomarkers at 2 hours remained independent predictors of AKI with an odds ratio of 1.003 (95% confidence interval: 1.000 to 1.006; P = 0.0364). These studies demonstrate that semaphorin 3A and netrin-1 can be useful early diagnostic biomarkers of AKI after liver transplantation

The radiolytic studies of panipenem in the solid state

The influence of ionizing radiation on the physicochemical properties of panipenem in solid state was studied. In the first part of our studies, we evaluated the possibility of applying radiosterilization to obtain sterile panipenem. Spectroscopic (FT-IR, Raman), chromatography (HPLC and HPLC-MS) and X-ray powder diffraction (XRPD) studies have shown that irradiation of ertapenem with the 25 kGy, the dose required to achieve sterility, does not change the physicochemical properties of the studied compound. The antimicrobial activity of panipenem irradiated with the dose of 25 kGy was reduced for three species. It was confirmed that the decrease in antimicrobial activity might be related to isomerization of panipenem