Effects of fine-scale environmental heterogeneity on local genetic structure in Macoma balthica from the Gulf of Gdañsk (southern Baltic Sea)

Surveys of unionid populations have been incorporated into the Swedish national environmental monitoring program. Nevertheless there is still lack of knowledge of important aspects of the biology of many unionid species. There may also be differences between species. This work compares the spatial distribution of two unionid species, Anodonta anatina and Unio tumidus, at four sites in Sweden. Samples were taken at transects along the shoreline at different water depths on the surface bed and in the sediments. Individual mussel ages were determined. Our results indicated that younger mussel individuals do not show differences in horizontal spatial distribution compared to older mussel individuals. However, they showed a preference to be burrowed in the sediment compared to older individuals that were predominantly found at the sediment surface. We also found a large difference in burrowing frequency between species with a higher frequency of burrowed adult individuals of A. anatina than U. tumidus. This result may be due to the timing of our field survey that coincided with the period of glochidia release for U. tumidus. We can conclude that a monitoring program for freshwater mussel populations needs to be carefully planned in time.     

Triterpene saponosides from Lysimachia ciliata differentially attenuate invasive potential of prostate cancer cells

Neither androgen ablation nor chemotherapeutic agents are effective in reducing the risk of prostate cancer progression. On the other hand, multifaceted effects of phytochemicals, such as triterpene saponins, on cancer cells have been suggested. A promising safety and tolerability profile indicate their possible application in the treatment of advanced prostate cancers. We analyzed the specificity, selectivity and versatility of desglucoanagalloside B effects on human prostate cancer cells derived from prostate cancer metastases to brain (DU-145 cells) and bone (PC-3 cells). Prominent growth arrest and apoptotic response of both cell types was observed in the presence of sub-micromolar desglucoanagalloside B concentrations. This was accompanied by cytochrome c release and caspase 3/7 activation. A relatively low cytostatic and pro-apoptotic response of cancer cells to a desglucoanagalloside B analog, anagallosaponin IV, illustrated the specificity of the effects of desglucoanagalloside B, whereas the low sensitivity of normal prostate PNT2 cells to desglucoanagalloside B showed the selectivity of its action. Inhibition of cancer cell motility was observed in the presence of both saponins, however only desglucoanagalloside B attenuated cancer cell invasive potential, predominantly through an effect on cell elastic properties. These data demonstrate the versatility of its effects on prostate cancer cells. In contrast to PNT2 cells, cancer cells tested in this study were relatively resistant to mitoxantrone. The multifaceted action of desglucoanagalloside B on basic cellular traits, crucial for prostate cancer progression, opens perspectives for elaboration of combined palliative therapies and new prostate cancer prophylaxis regimens.     

Impaired dynamics of the late endosome/lysosome compartment in human Niemann-Pick type C skin fibroblasts carrying mutation in NPC1 gene

The Niemann-Pick type C (NPC) disease is characterized by accumulation of lipids within the late endosome/lysosome (LE/LY) compartment as a result of dysfunctions of the NPC1 or NPC2 proteins and an altered distribution and/or functioning of proteins involved in the regulation of membrane dynamics. In our previous report we isolated membranes of the LE/LY compartment from NPC L1 skin fibroblasts with a mutation in the NPC1 gene (exon 8, R348X) and showed that annexin A6 (AnxA6) may contribute to the impaired dynamics of these membranes in a cholesterol-dependent manner and therefore to the overnormative storage of cholesterol. In this report we show that the LE/LY fraction isolated from NPC L1 cells is characterized by a 4-fold enrichment in cholesterol, 2.5-fold in sphingomyelin and 2-fold in saturated fatty acids. As a result, the fluidity of LE/LY membranes isolated from NPC L1 cells is greatly reduced in comparison to control ones. We conclude that modified lipid composition and properties of this compartment may affect distribution and function of proteins implicated in cellular membrane dynamics. As a consequence, the backward vesicular transport of cholesterol from the LE/LY compartment to the Golgi apparatus, endoplasmic reticulum and finally to plasma membrane is impaired.     

Role of N-acetyl-beta-d-hexosaminidase in cholesteatoma tissue

Cholesteatoma is a destructive disease characterized by the progressive expansion of keratinizing squamous epithelium in the middle ear and mastoid, and chronic inflammatory reaction of the subepithelial connective tissue. N-Acetyl-beta-d-hexosaminidase (HEX) catalyzes the release of terminal non-reducing N-acetyl-d-hexosamine residues acting on glucosides and galactosides in glycoproteins, G(M2)-gangliosides and glycosaminoglycans (GAGs). In this study the activities of HEX were measured in cholesteatoma tissue and in normal skin to demonstrate a possible role of HEX in bone resorption in the area adjacent to cholesteatoma. Cholesteatomas (n = 21) and normal adult retroauricular skin (controls, n = 21), were collected from patients during surgery due to chronic otitis media. In 20 of 21 specimens a significantly higher activity of HEX was observed in cholesteatoma tissue compared with that in normal skin. Mean release of HEX from the activated cells was 68.55 +/- 30.77 nkat/g wet tissue in cholesteatoma and 31.79 +/- 10.02 nkat/g wet tissue in skin specimens. It may explain the process of bone resorption in the area adjacent to cholesteatoma, i.e. ossicles or temporal bone. This study suggests that drugs inhibiting HEX activity, such as iminocyclitols, may be useful in cholesteatoma treatment.     

Modification of thiamine pyrophosphate dependent enzyme activity by oxythiamine in Saccharomyces cerevisiae cells

Oxythiamine is an antivitamin derivative of thiamine that after phosphorylation to oxythiamine pyro phosphate can bind to the active centres of thiamine-dependent enzymes. In the present study, the effect of oxythiamine on the viability of Saccharomyces cerevisiae and the activity of thiamine pyrophosphate dependent enzymes in yeast cells has been investigated. We observed a decrease in pyruvate decarboxylase specific activity on both a control and an oxythiamine medium after the first 6 h of culture. The cytosolic enzymes transketolase and pyruvate decarboxylase decreased their specific activity in the presence of oxythiamine but only during the beginning of the cultivation. However, after 12 h of cultivation, oxythiamine-treated cells showed higher specific activity of cytosolic enzymes. More over, it was established by SDS-PAGE that the high specific activity of pyruvate decarboxylase was followed by an increase in the amount of the enzyme protein. In contrast, the mitochondrial enzymes, pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase complexes, were inhibited by oxythiamine during the entire experiment. Our results suggest that the observed strong decrease in growth rate and viability of yeast on medium with oxythiamine may be due to stronger inhibition of mitochondrial pyruvate dehydrogenase than of cytosolic enzymes.     

Factors controlling hydrochemical and trophic state variables in 86 shallow lakes in Europe

The total nitrogen mass balance was studied over a two-year period in two reservoirs located in south-eastern Poland. Theobserved nitrogen retention (N_ret) inthe reservoirs ranged from 0.18 to 2.12g m^-2d^-1 (mean 0.83g m^-2d^-1) in case of theRzeszów Reservoir and from -0.02 to0.41 g m^-2d^-1 (mean 0.13g m^-2d^-1) in case of the SolinaReservoir, while the percentage retention(N_ret) ranged from 7 to 42% (mean22%) and -15 to 73% (mean 35%),respectively. A good relationship betweenN_ret and nitrogen loads was observedfor the Solina Reservoir. The data obtainedby the author and collected from theresearches of 6 other reservoirs located insouthern Poland were used to develop anempirical model suitable to predict thenitrogen seasonal dynamics in a reservoir.The model allows for the determination ofboth the annual mean N_ret value andits seasonal variation in a reservoir.     

Pulsed feeding strategy is more favorable to medium‐chain‐length polyhydroxyalkanoates production from waste rapeseed oil

This article presents the results of production and characterization of medium‐chain‐length polyhydroxyalkanoates (mcl‐PHAs) using Pseudomonas sp. Gl01. Studies have been carried out to find suitable feeding strategies for mcl‐PHAs production and, for the first time, to investigate in‐depth the properties of biopolyesters obtained under controlled conditions with waste rapeseed oil as a substrate. Up to 44% mcl‐PHAs of cell dry weight was produced at 41 h of biofermentor culture by employing pulsed feeding of waste rapeseed oil. GC analysis showed a polymer composition with monomer length of C₆ to C₁₂ with C₈ and C₁₀ as the principal monomers. The monomeric structure of the extracted polyesters did not depend on the cultivation time and the feeding strategy. Molecular weight of the mcl‐PHAs was found to be ranging from 57 to 154 kDa. Thermal analyses showed the obtained mcl‐polyhydroxyalkanaotes to be semi‐crystalline biopolymer with promising thermal stability, having a glass transition temperature of ?38 to ?50°C. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1243–1246, 2014     

Nutrition transition and dietary energy availability in Eastern Europe after the collapse of communism.

After the economic transition of the late 1980s and early 1990s there was a rapid increase in overweight and obesity in many countries of Eastern Europe. This article describes changing availability of dietary energy from major dietary components since the transition to free-market economic systems among Eastern European nations, using food balance data obtained at national level for the years 1990-92 and 2005 from the FAOSTAT-Nutrition database. Dietary energy available to the East European nations satellite to the former Soviet Union (henceforth, Eastern Europe) was greater than in the nations of the former Soviet Union. Among the latter, the Western nations of the former Soviet Union had greater dietary energy availability than the Eastern and Southern nations of the former Soviet Union. The higher energy availability in Eastern Europe relative to the nations of the former Soviet Union consists mostly of high-protein foods. There has been no significant change in overall dietary energy availability to any category of East European nation between 1990-1992 and 2005, indicating that, at the macro-level, increasing rates of obesity in Eastern European countries cannot be attributed to increased dietary energy availability. The most plausible macro-level explanations for the obesity patterns observed in East European nations are declines in physical activity, increased real income, and increased consumption of goods that contribute to physical activity decline: cars, televisions and computers.