24 research outputs found
Structure and Function of Enterocyte in Intrauterine Growth Retarded Pig Neonates
The intestine of intrauterine growth retarded (IUGR) neonates showed different morphology compared to neonates born with normal body weight (NBW). The aim of the present study was to investigate the ultrastructure and proteomic profile of the gut epithelium in IUGR pig neonates with special attention to the digestive and absorptive function. Intestine tissue samples were investigated in 7-day-old IUGR and NBW littermate piglets using histometry, immunofluorescence, scanning electron microscopy (SEM), and mass spectrometry analysis. IUGR piglets have shown reduced mucosa and muscularis thickness and an enhanced number of foetal type enterocytes (FTE). SEM studies have shown the lack of the characteristic large-size vacuole in IUGR’s enterocytes. Delayed removal of FTE in IUGR neonates was probably due to the inhibited apoptosis in the apical part of villi and increased apoptosis and reduced mitosis in the crypt region. In the expression of proteins in the intestinal mucosa such as hexokinase I, histones, and prelamin A/C, carbamoyl phosphate was reduced in IUGR neonates. Finally, IUGR intestines showed higher expression of HSPA9 and HSPA5 as apoptosis markers. The data indicate modifications of gut mucosa in IUGRs that may result in slower gut mucosa maturation and reduced utilisation of nutrient as compared to NBW pig neonates
Differential Levels of Stress Proteins (HSPs) in Male and Female Daphnia magna in Response to Thermal Stress: A Consequence of Sex-Related Behavioral Differences?
In two independent experiments, we compared: (1) water depth selection (and accompanying temperature selection) by male and female Daphnia magna under different kinds of environmental stress, including the presence of filamentous cyanobacteria, the risk of predation from fish, and the presence of toxic compounds; and (2) sex-dependent production of heat shock proteins (HSP60, 70, and 90) in response to a sudden change in temperature. Male D. magna selected deep water strata, which offer a relatively stable environment, and thereby avoided the threat of predation and the presence of toxic compounds in surface waters. Correlated with this behavior, males reduce their molecular defenses against stress, such as the production of heat shock proteins (HSPs), and do not maintain the physiological machinery that triggers an increase in HSP levels in response to stress. In contrast, female D. magna actively select habitats that offer optimal conditions for growth and production of offspring. Consequently, females are exposed to variable environmental conditions that may be associated with increased stress. To permit survival in these different habitats, D. magna females require molecular mechanisms to protect their cells from rapid changes in stress levels. Thus, they maintain high constitutive levels of the heat shock proteins from HSP 60, 70, and 90 families, and they have the potential to further enhance the production of the majority of these proteins under stress conditions. The results of this study indicate that the separate habitats selected by male and female D. magna result in different patterns of HSP production, leading us to hypothesize that that male and female Daphnia magna adopt different strategies to maximize the fitness of the species
ALKBH overexpression in head and neck cancer: potential target for novel anticancer therapy
The nine identified human homologues of E. coli AlkB 2-oxoglutarate (2OG) and Fe(II)-dependent dioxygenase, ALKBH1-8 and FTO, display different substrate specificities and diverse biological functions. Here we discovered the combined overexpression of members of the ALKBH family in head and neck squamous cell carcinomas (HNSCC). We found direct correlation of ALKBH3 and FTO expression with primary HNSCC tumor size. We observed unidentified thus far cytoplasmic localization of ALKBH2 and 5 in HNSCC, suggesting abnormal role(s) of ALKBH proteins in cancer. Further, high expression of ALKBHs was observed not only in HNSCC, but also in several cancerous cell lines and silencing ALKBH expression in HeLa cancer cells resulted in dramatically decreased survival. considering the discovered impact of high expression of ALKBH proteins on HNSCC development, we screened for ALKBH blockers among newly synthetized anthraquinone derivatives and demonstrated their potential to support standard anticancer therapy
The effect of pharmaceuticals on selected components of aquatic food web
The effect of pharmaceuticals on selected components of aquatic food webPharmaceuticals regularly contaminate freshwater ecosystems all over the world. Permanent discharge of pharmaceuticals to the environment causes chronic exposure of aquatic organisms to chemical pollutants, often posing to them the direct threat.In the freshwater environment, drugs are detected in nanograms per liter, while the concentrations used in experiments conducted to investigate their impact on aquatic organisms are usually significantly higher (milligrams per liter). The scarcity of research on the effects of environmentally relevant concentrations of pharmaceuticals on so-called non-target organisms, has remained a problem.Freshwater environments are complex systems, vulnerable to change. Algae constitute an important component of these ecosystems, as they are key primary producers in most aquatic environments, forming the basis of the food web. Toxic effects of contaminants at this level could bring about the negative consequences for organisms from higher trophic levels.Primary consumers such as filter feeding cladocerans, including those of the genus Daphnia, occupy a central position in freshwater trophic networks. Daphnia play a major role in controlling algal biomass. On the other hand, planktonic animals (and Daphnia among them), constitute the essential food for planktivorous fish. Changes in any of parameters related to fitness caused by the presence of pharmaceuticals can affect the dynamics and biomass of planktonic crustaceans, thus, the functioning of the aquatic food webs.The aim of my doctoral thesis was to determine the direct, long-term effects of pharmaceuticals in the concentrations registered in the environment on aquatic organisms from different trophic levels, and to examine the possible transfer of medicines’ effects along the trophic chain. In the study on the sensitivity of aquatic organisms to medicines (cyclophosphamide, fluoxetine, ibuprofen, and propranolol), wide range of methods and indicators was used. In primary producers – algae (Acutodesmus obliquus, Chlamydomonas reinhardtii and Nannochloropsis limnetica), I analyzed cell growth, pigments (chlorophyll, carotenoids) concentrations, photosynthesis and fatty acids profile. In primary consumers - Daphnia, I measured the growth rate, age and size at the first reproduction and number of offspring. Changes in Daphnia proteome caused by the presence of pharmaceutical were also analyzed.In the study of the effects of pharmaceuticals on aquatic organisms from various trophic levels, both traditional (EC50 designation) and innovative (long-term exposure to environmental drug doses) approach was used. For the first time rapid light curves in the Phyto-PAM was used in ecotoxicological study concerning the effect of pharmaceuticals on aquatic biota.It has been for the first time demonstrated that (i) even low doses of medicines can significantly affect eukaryotic aquatic organisms from two trophic levels (primary producers and first-order consumers), (ii) the impact of pharmaceuticals can spread to other trophic levels (from primary producers to first-order consumers).Wpływ farmaceutyków na wybrane komponenty sieci troficznej w ekosystemach wodnych.Farmaceutyki są regularnie wykrywane w wodach słodkich na całym świecie. Stałe przedostawanie się farmaceutyków do środowiska naraża organizmy wodne na chroniczną na nie ekspozycję, często stanowiąc dla nich bezpośrednie zagrożenie.W środowisku słodkowodnym leki wykrywane są w stężeniach rzędu nanogramów na litr, natomiast stężenia stosowane w eksperymentach służących poznaniu ich wpływu na organizmy wodne są zazwyczaj znacząco wyższe. Brakuje zatem danych dotyczących wpływu leków w stężeniach rejestrowanych w środowisku na organizmy słodkowodne. Środowiska słodkowodne są systemami złożonymi. Podstawę pelagicznej piramidy troficznej budują glony planktonowe, a toksyczne działanie zanieczyszczeń na organizmy pierwszego poziomu troficznego może pośrednio powodować negatywne skutki dla organizmów wyższych poziomów troficznych. Konsumenci I rzędu jakimi są filtrujące wioślarki planktonowe zajmują centralną pozycję w słodkowodnych sieciach troficznych. Z jednej strony kontrolują one biomasę fitoplanktonu, z drugiej stanowią zasadniczy pokarm ryb planktonożernych. Zmiany któregokolwiek z parametrów biologii wioślarek planktonowych spowodowane bezpośrednim lub pośrednim wpływem farmaceutyków mogą mieć znaczące skutki dla ichtiofauny, a co za tym idzie, dla funkcjonowania całego ekosystemu.Celem rozprawy doktorskiej było określenie bezpośredniego, długotrwałego wpływu leków w dawkach rejestrowanych w środowisku na organizmy wodne z dwóch różnych poziomów troficznych oraz scharakteryzowanie ewentualnego przenoszenia się wpływu leków wzdłuż sieci troficznej. W badaniach wrażliwości organizmów wodnych na leki (cyklofosfamid, fluoksetyne, ibuprofen, propranolol) zastosowano szeroki wachlarz metod i wskaźników. U producentów pierwotnych - glonów (Acutodesmus obliquus, Chlamydomonas reinhardtii i Nannochloropsis limnetica) analizowałam wzrost komórek, zawartość barwników (chlorofilu, karotenoidów), wydajność fotosyntezy i profil tłuszczowy. U konsumentów I rzędu – Daphnia magna, mierzyłam tempo wzrostu, wiek i wielkość przy pierwszej reprodukcji oraz liczbę potomstwa. Analizowałam również zmiany w proteomie spowodowane obecnością farmaceutyku.W pracy zastosowano zarówno tradycyjne (wyznaczenie EC50) jak i nowatorskie (długotrwała ekspozycja na środowiskowe dawki leków) podejście eksperymentalne. Po raz pierwszy w laboratoryjnych badaniach ekotoksykologicznych wykorzystano analizę transportu elektronów w zależności od natężenia światła (phyto PAM), w celu zbadania wpływu leków na fotosyntezą przedstawicieli fitoplanktonu. Po raz pierwszy wykazano że: (i) nawet niskie dawki leków mogą istotnie wpływać na eukariotyczne organizmy wodne z dwóch poziomów troficznych (producentów pierwotnych i konsumentów I rzędu), (ii) wpływ farmaceutyków może przenosić się na kolejne poziomy troficzne (od producentów pierwotnych do konsumentów I rzędu)
Correction: How cyclophosphamide at environmentally relevant concentration influences Daphnia magna life history and its proteome.
[This corrects the article DOI: 10.1371/journal.pone.0195366.]
When males outlive females Archive Data
Lifespan (LS) data for D. magna clones (K), (T) and (B), for males (M) and females (F), recorded at temperature (16) and (20) degrees. The death of an individual was either observed (fin=1), or an individual lived to the end of the experiment (fin=0)
The relationship between the manifestations of mobbing and reactions of mobbing victims
Background: The study concerned workplace mobbing, a phenomenon affecting about 3–20% of the Polish population. The aim of the article is to distinguish the manifestations of mobbing, to study the coexistence of mobbing manifestations, and to search for the relationships between the symptoms of mobbing, reactions to mobbing and methods of dealing with mobbing used by victims. Material and Methods: Information on the above variables was obtained using a questionnaire on mobbing, risk factors, and responses to mobbing. The questionnaire was completed by 781 people (women: 66%, men: 34%). The average age of the respondents was 29 years. The current statistical analysis included: distinguishing the manifestations of mobbing by means of a confirmatory factor analysis, studying the coexistence of mobbing manifestations by means of a cluster analysis, and detecting the relationships between mobbing manifestations, reactions to mobbing and ways of dealing with it based on the system of structural equations. Results: The results of the research revealed 3 categories of relationships: a co-occurrence of mobbing manifestations, a relationship of mobbing manifestations with reactions to mobbing, and a relationship of mobbing reactions with methods of dealing with mobbing. Conclusions: Mobbing was found in 22% of the examined group. The study revealed the existence of 5 clusters of mobbing manifestations (i.e., subgroups of respondents characterized by experiencing at least 1 of the mobbing manifestations). In the most numerous clusters in which the symptoms of mobbing were diagnosed, unfriendly working conditions prevailed. In the context of mobbing, people were found to more often react with passivity or with using interpersonal coping methods. However, they rarely turned to institutions for help or used aggression against the mobber. Med Pr. 2022;73(1):1–1
Data from: When males outlive females: sex-specific effects of temperature on lifespan in a cyclic parthenogen
Lifespans of males and females frequently differ as a consequence of different life history strategies adopted to maximize fitness. It is well visible in cyclic parthenogens, such as water fleas of the genus Daphnia, where males appear in the population usually only for periods when receptive females are available. Moreover, even within one sex, different life history strategies and mechanisms regulating lifespan may exist. Previous studies suggested that Daphnia males may regulate their lifespan by staying in colder waters than females. We hypothesize that such behavioural mechanism should be associated with stronger reaction to low temperature that is greater lifespan extension in males than in females. In this study, we monitored survivorship of Daphnia magna females and males of three clonal lines cultured at 16 or 20°C. The results did not provide a species-level corroboration of our hypothesis, instead, they revealed very strong intraspecific differences in the responses of male and female lifespan to temperature change. They further suggest the existence of parallel life history strategies, hypotheses whose tests would bring new insights into the ecology of males in cyclic parthenogens
Photosynthetic activity in both algae and cyanobacteria changes in response to cues of predation
A plethora of adaptive responses to predation has been described in microscopic aquatic producers. Although the energetic costs of these responses are expected, with their consequences going far beyond an individual, their underlying molecular and metabolic mechanisms are not fully known. One, so far hardly considered, is if and how the photosynthetic efficiency of phytoplankton might change in response to the predation cues. Our main aim was to identify such responses in phytoplankton and to detect if they are taxon-specific. We exposed seven algae and seven cyanobacteria species to the chemical cues of an efficient consumer, Daphnia magna, which was fed either a green alga, Acutodesmus obliquus, or a cyanobacterium, Synechococcus elongatus (kairomone and alarm cues), or was not fed (kairomone alone). In most algal and cyanobacterial species studied, the quantum yield of photosystem II increased in response to predator fed cyanobacterium, whereas in most of these species the yield did not change in response to predator fed alga. Also, cyanobacteria tended not to respond to a non-feeding predator. The modal qualitative responses of the electron transport rate were similar to those of the quantum yield. To our best knowledge, the results presented here are the broadest scan of photosystem II responses in the predation context so far