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result(s) for
"Witkowska, Ewa"
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How Does Education Quality Affect Economic Growth?
by
Witkowska, Ewa
,
Goczek, Łukasz
,
Witkowski, Bartosz
in
Cognition & reasoning
,
Economic aspects
,
Economic growth
2021
In a seminal article, Hanushek and Woessmann explained economic growth as a function of the quality of education. While they did not find evidence of the importance of years of schooling, they argued for the relevance of cognitive skills and a basic literacy ratio for economic growth. However, this result was based on cross-country data limited to 23 observations. In this study, we extended and modified their approach based on the results of PISA (Programme for International Student Assessment) tests to explain the GDP changes over the last 50 years. Using panel data, we considered the possible lag that characterizes this relationship, used statistical methods to address the risk of reversed causality of economic performance affecting the quality of education, and extended the model by the inclusion of other potential growth factors. The results, which also included several robustness checks, confirmed the relevance of earlier education quality as a significant growth factor. Our results suggest the significance of educational skills for GDP growth, which might be treated as a confirmation of the importance of quality primary and secondary education for economic development. We showed that our results are robust to changes in the order of lags and confirmed the validity of the conclusion with the use of specification-robust Bayesian model averaging.
Journal Article
High-Molecular-Mass APOBEC3G Complexes Restrict Alu Retrotransposition
by
Soros, Vanessa B.
,
Santiago, Mario
,
Chiu, Ya-Lin
in
Alu Elements
,
Antibodies
,
Antiretroviral agents
2006
APOBEC3G (A3G) and related deoxycytidine deaminases are potent intrinsic antiretroviral factors. A3G is expressed either as an enzymatically active low-molecular-mass (LMM) form or as an enzymatically inactive high-molecular-mass (HMM) ribonucleoprotein complex. Resting CD4 T cells exclusively express LMM A3G, where it functions as a powerful postentry restriction factor for HIV-1. Activation of CD4 T cells promotes the recruitment of LMM A3G into 5- to 15-MDa HMM complexes whose function is unknown. Using tandem affinity purification techniques coupled with MS, we identified Staufen-containing RNA-transporting granules and Ro ribonucleoprotein complexes as specific components of HMM A3G complexes. Analysis of RNAs in these complexes revealed Alu and small Y RNAs, two of the most prominent nonautonomous mobile genetic elements in human cells. These retroelement RNAs are recruited into Staufen-containing RNA-transporting granules in the presence of A3G. Retrotransposition of Alu and hY RNAs depends on the reverse transcriptase machinery provided by long interspersed nucleotide elements 1 (L1). We now show that A3G greatly inhibits L1-dependent retrotransposition of marked Alu retroelements not by inhibiting L1 function but by sequestering Alu RNAs in cytoplasmic HMM A3G complexes away from the nuclear L1 enzymatic machinery. These findings identify nonautonomous Alu and hY retroelements as natural cellular targets of A3G and highlight how different forms of A3G uniquely protect cells from the threats posed by exogenous retroviruses (LMM A3G) and endogenous retroelements (HMM A3G).
Journal Article
Does an increase in education quality cause developing countries to catch up?
by
Witkowska, Ewa
,
Goczek, Łukasz
,
Witkowski, Bartosz
in
Causality
,
Developing countries
,
Economic growth
2022
We investigate whether increasing the education quality causes increases in economic growth allowing poorer countries to catch up. To this end, we extend Nelson-Phelps's classic paper by introducing differences in education quality (proxied by students' performance on the Program for International Student Assessment [PISA] test) in a leader-follower type of growth model with knowledge diffusion. We use students' performance in a standardized international PISA test to measure education quality's impact on economic growth using a panel Vector Error Correction allowing for cross-correlation in the co-integration analysis in a set of all countries observed over the years 1975–2018. Additionally, we consider the possible reverse causality that characterizes economic development and the quality of education. Our results confirm the relevance of education quality as a significant causal factor of economic growth. However, further analyses indicate that the discussed relation is long-run, which may have important implications for policymakers.
Journal Article
Synthesis, Physicochemical and Biological Study of Gallium-68- and Lutetium-177-Labeled VEGF-A165/NRP-1 Complex Inhibitors Based on Peptide A7R and Branched Peptidomimetic
by
Gniazdowska, Ewa
,
Misicka, Aleksandra
,
Tymecka, Dagmara
in
68Ga/177Lu-radiopharmaceuticals
,
A7R peptide
,
Amino acids
2022
Neuropilin-1 (NRP-1) is a surface receptor found on many types of cancer cells. The overexpression of NRP-1 and its interaction with vascular endothelial growth factor-165 (VEGF165) are associated with tumor growth and metastasis. Therefore, compounds that block the VEGF165/NRP-1 interaction represent a promising strategy to image and treat NRP-1-related pathologies. The aim of the presented work was to design and synthesize radioconjugates of two known peptide-type inhibitors of the VEGF165/NRP-1 complex: A7R peptide and its shorter analog, the branched peptidomimetic Lys(hArg)-Dab-Pro-Arg. Both peptide-type inhibitors were coupled to a radionuclide chelator (DOTA) via a linker (Ahx) and so radiolabeled with Ga-68 and Lu-177 radionuclides, for diagnostic and therapeutic uses, respectively. The synthesized radioconjugates were tested for their possible use as theranostic-like radiopharmaceuticals for the imaging and therapy of cancers that overexpress NRP-1. The obtained results indicate good efficiency of the radiolabeling reaction and satisfactory stability, at least 3t1/2 for the 68Ga- and 1t1/2 for the 177Lu-radiocompounds, in solutions mimicking human body fluids. However, enzymatic degradation of both the studied inhibitors caused insufficient stability of the radiocompounds in human serum, indicating that further modifications are needed to sufficiently stabilize the peptidomimetics with inhibitory properties against VEGF165/NRP-1 complex formation.
Journal Article
Scandium-44 Radiolabeled Peptide and Peptidomimetic Conjugates Targeting Neuropilin-1 Co-Receptor as Potential Tools for Cancer Diagnosis and Anti-Angiogenic Therapy
2023
Pathological angiogenesis, resulting from an imbalance between anti- and pro-angiogenic factors, plays a pivotal role in tumor growth, development and metastasis. The inhibition of the angiogenesis process by the VEGF/VEGFR-2/NRP-1 pathway raises interest in the search for such interaction inhibitors for the purpose of the early diagnosis and treatment of angiogenesis-dependent diseases. In this work we designed and tested peptide-based radiocompounds that selectively bind to the neuropilin-1 co-receptor and prevent the formation of the pro-angiogenic VEGF-A165/NRP-1 complex. Three biomolecules, A7R and retro-inverso DR7A peptides, and the branched peptidomimetic Lys(hArg)-Dab-Pro-Arg (K4R), conjugated with macrocyclic chelator through two linkers’ types, were labeled with theranostic scandium-44 radionuclide, and studied in vitro as potential targeted radiopharmaceuticals. ELISA (enzyme-linked immunosorbent assay) studies showed no negative effect of the introduced biomolecules’ changes and high NRP-1 affinity in the case of A7R- and K4R-radiocompounds and a lack affinity for DR7A-radiocompounds. All radiopeptides showed a hydrophilic nature as well as high stability against ligand exchange reactions in cysteine/histidine solutions. Unfortunately, all radiocompounds showed unsatisfactory nano-scale stability in human serum, especially for use as therapeutic radioagents. Further work is ongoing and focused on the search for angiogenesis inhibitors that are more human serum stable.
Journal Article
Micropropagation of Chaenomeles japonica: A Step towards Production of Polyphenol-rich Extracts Showing Antioxidant and Antimicrobial Activities
by
Studzińska-Sroka, Elżbieta
,
Kikowska, Małgorzata
,
Rewers, Monika
in
Acids
,
Anti-Infective Agents - chemistry
,
Anti-Infective Agents - pharmacology
2019
A protocol for C. japonica micropropagation with a confirmation of genome size stability of the in vitro-propagated plantlets was developed. The highest number of shoots multiplied in vitro was obtained on Murashige & Skoog medium (MS) with 1.0 mg L−1 N6-benzyladenine plus 1.0 mg L−1 indole-3-acetic acid. The highest number of roots was observed for the shoots on MS with 15 g L−1 sucrose plus 1.0 mg L−1 indole-3-acetic acid. The acclimatization rate was significantly high. The qualitative HPLC analyses confirmed the presence of phenolic acids and flavonoids in the extracts. The extracts from both shoot cultures and the leaves from field-grown plants revealed antioxidant activity and they exhibited moderate antimicrobial activity. The conducted research confirmed the regeneration potential of genetically-stable plants of C. japonica under in vitro conditions, the ability of the plantlets to produce polyphenols as those present in field-grown plants, as well as their antioxidant potential.
Journal Article
Preclinical evaluation of 18FSYN1 and 18FSYN2, novel radiotracers for PET myocardial perfusion imaging
by
Łyczko, Krzysztof
,
Witkowska-Patena, Ewa
,
Dziuk, Mirosław
in
Cardiac Imaging
,
Cardiotracer
,
Cardiovascular disease
2024
Background
Positron emission tomography (PET) is now an established diagnostic method for myocardial perfusion imaging (MPI) in coronary artery disease, which is the main cause of death globally. The available tracers show several limitations, therefore, the
18
F-labelled tracer is in high demand nowadays. The preclinical studies on normal Wistar rats aimed to characterise two potential, novel radiotracers, [
18
F]SYN1 and [
18
F]SYN2, to evaluate which is a better candidate for PET MPI cardiotracer.
Results
The dynamic microPET images showed rapid myocardial uptake for both tracers. However, the uptake was higher and also stable for [
18
F]SYN2, with an average standardized uptake value of 3.8. The biodistribution studies confirmed that [
18
F]SYN2 uptake in the cardiac muscle was high and stable (3.02%ID/g at 15 min and 2.79%ID/g at 6 h) compared to [
18
F]SYN1 (1.84%ID/g at 15 min and 0.32%ID/g at 6 h). The critical organs determined in dosimetry studies were the small intestine and the kidneys. The estimated effective dose for humans was 0.00714 mSv/MBq for [
18
F]SYN1 and 0.0109 mSv/MBq for [
18
F]SYN2. The tested dose level of 2 mg/kg was considered to be the No Observed Adverse Effect Level (NOAEL) for both candidates. The better results were achieved for [
18
F]SYN2, therefore, further preclinical studies were conducted only for this tracer. Radioligand binding assays showed significant responses in 3 from 68 assays: muscarinic acetylcholine M
1
and M
2
receptors and potassium channel hERG. The compound was mostly metabolised via an oxidative N-dealkylation, while the fluor substituent was not separated from the molecule.
Conclusion
[
18
F]SYN2 showed a favourable pharmacodynamic and pharmacokinetic profile, which enabled a clear visualization of the heart in microPET. The compound was well-tolerated in studies in normal rats with moderate radiation exposure. The results encourage further exploration of [
18
F]SYN2 in clinical studies.
Journal Article
Mass spectrometry-based analyses showing the effects of secretor and blood group status on salivary N-glycosylation
by
Cuison, Severino
,
Ewa Witkowska, H.
,
Ng, Connie Jen
in
Biomedical and Life Sciences
,
Biotechnology
,
Cell Biology
2015
Background
The carbohydrate portions of salivary glycoproteins play important roles, including mediating bacterial and leukocyte adhesion. Salivary glycosylation is complex. Many of its glycoproteins present ABO and Lewis blood group determinants. An individual’s genetic complement and secretor status govern the expression of blood group antigens. We queried the extent to which salivary glycosylation varies according to blood group and secretor status. First, we screened submandibular/sublingual and parotid salivas collected as ductal secretions for reactivity with a panel of 16 lectins. We selected three lectins that reacted with the largest number of glycoproteins and one that recognized uncommon lactosamine-containing structures. Ductal salivas representing a secretor with complex blood group expression and a nonsecretor with a simple pattern were separated by SDS-PAGE. Gel slices were trypsin digested and the glycopeptides were individually separated on each of the four lectins. The bound fractions were de-
N
-glycosylated. LC–MS/MS identified the original glycosylation sites, the peptide sequences, and the parent proteins.
Results
The results revealed novel salivary
N
-glycosites and glycoproteins not previously reported. As compared to the secretor, nonsecretor saliva had higher levels of
N
-glycosylation albeit with simpler structures.
Conclusions
Together, the results suggested a molecular basis for inter-individual variations in salivary protein glycosylation with functional implications for oral health.
Journal Article
Synthesis and Structural Analysis of Polyester Prodrugs of Norfloxacin
by
Olędzka, Ewa
,
Kolodziejski, Waclaw
,
Sobczak, Marcin
in
aliphatic polyesters
,
Blood substitutes
,
Cancer
2008
Two-, three- and four-arm, star-shaped poly(ε-caprolactone) andpoly(D,L-lactide) homopolymers, and copolymers of ε-caprolactone with D,L-lactide weresynthesized via ring-opening polymerization of cyclic esters in the presence of glycerol,penthaerythritol and poly(ethylene glycol) as initiators and stannous octoate as a catalyst.Thus obtained oligomers were successfully used in the synthesis of novel macromolecularprodrugs of norfloxacin. The structures of the polymers and prodrugs were elucidated bymeans of MALDI-TOF MS, NMR and IR studies.
Journal Article
Diagnostic performance of 18F-PSMA-1007 PET/CT in biochemically relapsed patients with prostate cancer with PSA levels ≤ 2.0 ng/ml
2020
BackgroundThe aim of the study was to prospectively evaluate diagnostic performance of 18F-PSMA-1007 PET/CT in patients with prostate cancer (PCa) after radical treatment and low but rising prostate-specific antigen (PSA) levels.MethodsWe prospectively enrolled 40 consecutive patients after radical treatment (80%—radical prostatectomy, 20%—radiation beam therapy) of PCa and low (0.008 to ≤2.0 ng/ml), rising PSA. Skull to mid-thigh PET/CT imaging was performed 95 (±12) min after injection of 295.5 (±14.1) MBq 18F-PSMA-1007. Detection rate was correlated with PSA levels, Gleason score (GS) and T stage ≥ 3. PET/CT results were verified during 10.3 (±4.7) months follow-up to calculate sensitivity, specificity, negative predictive values (NPV) and positive predictive values (PPV).Results18F-PSMA-1007 PET/CT was positive in 24/40 patients, which yielded overall detection rate of 60%. Detection rate was 39%, 55% and 100% for PSA < 0.5, 0.5 to <1.0 and 1.0 to ≤2.0 ng/ml, respectively. PET/CT showed metastases in locoregional lymph nodes in 55% of patients, bones in 36% of patients and local recurrence in 9% of patients. Detection rate was correlated with PSA—a 0.1 ng/ml rise in PSA level increased odds for positive PET/CT by ~30%. PET/CT positivity was independent of GS and T stage. Verification of 40 lesions yielded sensitivity, specificity, PPV and NPV of 100%, 94.4%, 66.7% and 100%, respectively.Conclusions18F-PSMA-1007 PET/CT shows relatively high detection rate in patients with PCa after radical treatment and low, rising PSA levels. Like other PSMA-targeting radiotracers, its detection rate is dependent on PSA levels. 18F-PSMA-1007 also presents excellent sensitivity, specificity and NPV.
Journal Article