Characterization of the Partitioning System of Myxococcus Plasmid pMF1

pMF1 is the only autonomously replicating plasmid that has been recently identified in myxobacteria. This study characterized the partitioning (par) system of this plasmid. The fragment that significantly increased the retaining stability of plasmids in Myxococcus cells in the absence of selective antibiotics contained three open reading frames (ORFs) pMF1.21-pMF1.23 (parCAB). The pMF1.22 ORF (parA) is homologous to members of the parA ATPase family, with the highest similarity (56%) to the Sphingobium japonicum ParA-like protein, while the other two ORFs had no homologs in GenBank. DNase I footprinting and electrophoretic mobility shift assays showed that the pMF1.23 (parB) product is a DNA-binding protein of iteron DNA sequences, while the product of pMF1.21 (parC) has no binding activity but is able to enhance the DNA-binding activity of ParB to iterons. The ParB protein autogenously repressed the expression of the par genes, consistent with the type Ib par pattern, while the ParC protein has less repressive activity. The ParB-binding iteron sequences are distributed not only near the partitioning gene loci but also along pMF1. These results indicate that the pMF1 par system has novel structural and functional characteristics

d- and l-amino acids in Antarctic lakes: assessment of a very sensitive HPLC-MS method

Amino acids represent a fraction of organic matter in marine and freshwater ecosystems, and a source of carbon, nitrogen and energy. l-Amino acids are the most common enantiomers in nature because these chiral forms are used during the biosynthesis of proteins and peptide. To the contrary, the occurrence of d-amino acids is usually linked to the presence of bacteria. We investigated the distribution of l- and d-amino acids in the lacustrine environment of Terra Nova Bay, Antarctica, in order to define their natural composition in this area and to individuate a possible relationship with primary production. A simultaneous chromatographic separation of 40 l- and d-amino acids was performed using a chiral stationary phase based on teicoplainin aglycone (chirobiotic tag). The chromatographic separation was coupled to two different mass spectrometers-an LTQ-Orbitrap XL (Thermo Fisher Scientific) and an API 4000 (ABSciex)-in order to investigate their quantitative performance. High-performance liquid chromatography coupled with mass spectrometry methods were evaluated through the estimation of their linear ranges, repeatability, accuracy and detection and quantification limits. The high-resolution mass spectrometer LTQ-Orbitrap XL presented detection limits between 0.4 and 7 mu g l (-1), while the triple quadrupole mass spectrometer API 4000 achieved the best detection limits reported in the literature for the quantification of amino acids (between 4 and 200 ng l (-1)). The most sensitive method, HPLC-API 4000, was applied to lake water samples

The level of knowledge on nutrition and its relation to health among Polish young men

Background. Men are less than women interested in nutrition and health. Also low is their nutritional knowledge. More than 25% of men are unwilling to increase their knowledge about food and nutrition. The main sources of men’s knowledge about lifestyle including nutrition consist of Internet, colleagues and family. The low level of knowledge about nutrition and health among men is worrying especially in the context of their incidence of chronic non-communicable diseases like cardiovascular disease, higher than in women. Objective. The aim of the study was to determine the level of knowledge on nutrition and health among young men. Material and Methods. The study included 107 men aged 19-34 years from different places and backgrounds in Poland. Men were selected by the snowball method. The study was conducted using an authors’ validated questionnaire containing six types of closed questions (85 detailed questions in total). For statistical analysis Chi2 test was used (p≤0.05). Results. Almost 42% of men under the study were overweight or obese, and less than ¼ declared high physical activity, most showed (on a 4-point scale) sufficient (45%) or low level (40%) of knowledge of nutrition and health. Younger respondents had higher knowledge than older ones. Very low was the respondent’s awareness of an energy content of products, sources of high quality protein and amount of recommended vegetable and fruit consumption. The well-known were the reasons for civilisation diseases and the effect of dietary fibre. The internet was the main source of nutritional knowledge and health related information followed by: colleagues and family. Conclusions. The majority of men presented sufficient or low knowledge about food, nutrition and their relation to health. Young men should be encouraged to participate in various forms of nutritional and health education. This would increase the chance to avoid civilisation diseases.Wprowadzenie. Mężczyźni mniej niż kobiety interesują się zdrowiem i żywieniem. Mała jest też ich wiedza żywieniowa. Ponad 25% mężczyzn nie chce zwiększyć swej wiedzy o żywności i żywieniu. Głównymi źródłami wiedzy mężczyzn na temat stylu życia, w tym żywienia, są Internet oraz koledzy i rodzina. Niski poziom wiedzy żywieniowo-zdrowotnej jest niepokojący, szczególnie w kontekście występowania przewlekłych chorób niezakaźnych jak choroby układu krążenia, częściej niż u kobiet. Cel. Określenie poziomu wiedzy żywieniowo-zdrowotnej młodych mężczyzn. Materiał i metody. Badania obejmowały grupę 107 mężczyzn w wieku 19-34 lata, pochodzących z różnych miejsc oraz środowisk w Polsce. Mężczyźni zostali wybrani za pomocą metody „kuli śnieżnej”. Badania przeprowadzono metodą ankietową przy użyciu kwestionariusza autorskiej, zwalidowanej ankiety zawierającej 6 różnych pytań zamkniętych (w nich łącznie 85 pytań szczegółowych). Do analizy statystycznej użyto testu Chi2 przy poziomie istotności p ≤0.05. Wyniki. Około 42% badanych mężczyzn miało nadwagę lub otyłość, a niej niż 1/4 deklarowała aktywność fizyczną; w 4. stopniowej skali większość wykazała dostateczną (45%) albo małą (40%) wiedzę żywieniowo-zdrowotną. Młodsi respondenci mieli większą wiedzę niż starsi. Respondenci wykazali bardzo małą świadomość na temat wartości energetycznej produktów, źródeł wysoko wartościowego białka oraz zalecanych ilości spożywania warzyw i owoców. Dobrze znali przyczyny chorób cywilizacyjnych oraz wpływu błonnika pokarmowego na organizm. Głównym źródłem wiedzy żywieniowo-zdrowotnej był internet, a następnie koledzy oraz rodzina. Wnioski. Większość mężczyzn prezentowała dostateczną lub małą wiedzę o żywności i żywieniu oraz ich związkach ze zdrowiem. Młodzi mężczyźni powinni być zachęcani do udziału w różnych formach edukacji żywieniowej i zdrowotnej. Mogłoby to zwiększyć szanse ograniczenia przewlekłych chorób niezakaźnych

Large-conductance K+ channel opener CCS7184 as a regulator of endothelial cell function

Endothelium, Potassium channels, Channel openers, Mitochondri

Potassium currents in human myogenic cells from healthy and congenital myotonic dystrophy foetuses

The whole-cell patch clamp technique was used to record potassium currents in in vitro differentiating myoblasts isolated from healthy and myotonic dystrophy type 1 (DM1) foetuses carrying 2000 CTG repeats. The fusion of the DM1 myoblasts was reduced in comparison to that of the control cells. The dystrophic muscle cells expressed less voltage-activated K(+) (delayed rectifier and non-inactivating delayed rectifier) and inward rectifier channels than the age-matched control cells. However, the resting membrane potential was not significantly different between the control and the DM1 cells. After four days in a differentiation medium, the dystrophic cells expressed the fast-inactivating transient outward K(+) channels, which were not observed in healthy cells. We suggest that the low level of potassium currents measured in differentiated DM1 cells could be related to their impaired fusion