Anna Czapkiewicz

Erythrocyte membrane fatty acids in multiple myeloma patients

Mounting data show that fatty acids (FA) and fatty acid synthase (FAS) function could be potential targets for multiple myeloma (MM) therapy. Our study aimed at comparing the FA composition of erythrocyte membranes of MM patients and healthy controls. MM patients had higher saturated FA and n-6 polyunsaturated FA (PUFA) and lower monounsaturated, n-3 PUFA and trans-FA indices than controls. The n-3/n-6 PUFA ratio was lower in MM patients and there was distinct clustering of variants of individual FA in MM patients. The FA content of erythrocyte membrane could serve as a diagnostic and/or predictive biomarker in MM.

Plasma fatty acid profile in multiple myeloma patients

New membrane formation in the proliferating tumor cells consequently results in hypermetabolism of fatty acids (FA), as seen in many cancer patients, including multiple myeloma (MM). The FA composition of plasma reflects both endogenous synthesis as well as the dietary supply of these compounds. Additionally, obesity is a risk factor for the development of MM. The aim of this study was to compare the FA composition of plasma in 60 MM patients and 60 healthy controls. We noted significant differences in the FA profile of plasma from patients with MM when compared to the control group. Increased levels of saturated and n-6 polyunsaturated fatty acids in MM patients suggest that there may be increased endogenous synthesis of these fatty acids, likely due to increased expression of desaturase and elongase. Furthermore, cluster analysis showed differences in the distribution of FA in plasma from MM patients compared to controls. Dietary fat and a deranged endogenous FA metabolism may contribute to cancer-associated inflammation through an abnormal arachidonic acid metabolism, caused by pro-inflammatory derivatives. Our study supports further research on the biochemistry of lipids in patients with MM.

The four-factor asset pricing model on the Polish stock market

In the three-factor asset pricing model a cross sectional portfolio returns variation is explained by the excess return of the market portfolio (RM), stock capitalisation and a factor associated with the book-to-market (B/M) ratio. This model, however, does not explain the momentum effect. Since this effect is present on many stock markets, the three-factor model is augmented by the momentum factor. This article presents the study of the four-factor asset pricing model on the Warsaw Stock Exchange (WSE) which is one of the largest stock markets in Central and Eastern Europe. The empirical analysis is based on monthly data from the period April 2003–December 2012 which includes different stages of the business cycle. This article shows that momentum is a significant factor on the WSE and the four-factor model describes the returns variation much better than the three-factor model.

n-3 Fatty acids regulate the inflammatory-state related genes in the lung epithelial cells exposed to polycyclic aromatic hydrocarbons

BACKGROUND Chronic airway inflammation is coordinated by a complex of inflammatory mediators, including eicosanoids. The aim of this study was to evaluate the impact of polycyclic aromatic hydrocarbons (PAHs) on the human lung epithelial carcinoma A549 cells supplemented with docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids. METHODS We analyzed the influence of DHA, EPA and/or benzo(a)pyrene (BaP), chrysene (Chr), fluoranthene (Flu) and benzo(a)anthracene (Baa) treatment on the fatty acids (FAs) profile and the formation of isoprostanes. We studied the cyclooxygenase-2, FP-receptor, peroxisome proliferator-activated receptors PPARδ and PPARγ, transcription factor NF-кB p50 and p65 expression by Western blot, phospholipase A2 (cPLA2) activity, as well as aryl hydrocarbon receptor (AHR), cytochrome P450 (CYP1A1), phospholipase A2 (PLA2G4A) and prostaglandin synthase 2 (PTGS2) gene expression by qRT-PCR. RESULTS DHA or EPA supplementation and BaP or Baa treatment resulted in a higher level of PGF3α. COX-2 expression was decreased while PPARδ expression and cPLA2 activity was increased after fatty acid supplementation and PAHs treatment. DHA and EPA up-regulated AHR and PLA2G4A genes. CONCLUSIONS Supplementation with n-3 FAs resulted in changes of inflammatory-state related genes in the lung epithelial cells exposed to PAHs. The altered profile of lipid mediators from n-3 FA as well as repression of the COX-2 protein by n-3 PUFAs in A549 cells incubated with PAHs suggests anti-inflammatory and pro-resolving properties of DHA and EPA. It remains to be shown whether these pleiotropic and protective actions of n-3 FAs contribute to fish oils therapeutic effect in asthma.

An Application of Factor Pricing Models to the Polish Stock Market

ABSTRACT We evaluate and compare the performance of four popular factor pricing models: the capital asset pricing model, the Fama and French three-factor model, Carhart’s four-factor model, and the five-factor model of Fama and French. We aim to establish which of these models is most applicable in the Polish stock market. To do so, we employ a battery of tests—cross-sectional regressions, examination of one-way and two-way sorted portfolios, tests of monotonic relationships, and factor redundancy tests—and apply them to a sample of more than 1100 stocks for the years 2000–2018. The results indicate that the four-factor model outperforms the other models; it has the greatest explanatory ability for cross-sectional returns and is therefore well-suited for asset pricing in Poland.

Empirical Verification of World’s Regions Profitability in Dynamic International Investment Strategy

The main goal of the work is to present the empirical verification of the investment attractiveness in a given world financial region. The attractiveness of a region is represented by the share of assets from this region in the optimal portfolio. The multivariate GARCH model has been used to describe international dependencies. Optimal portfolios based on Value at Risk and Expected Shortfall minimization have been compared to the Markowitz portfolio. Indications, which should be taken into account by investors willing to invest in different world regions, have been presented as the result