Gene mapping of 28S and 5S rDNA sites in the spined loach Cobitis taenia (Pisces, Cobitidae) from a diploid population and a diploid–tetraploid population

We compare the chromosomal 28S and 5S rDNA patterns of the spined loach C. taenia (2n = 48) from an exclusively diploid population and from a diploid–polyploid population using 28S and 5S rDNA probe preparation and labelling, and fluorescence in situ hybridization (FISH). The 5S rDNA was located in two to three chromosome pairs, and separated from the 28S loci for the males and one female (F1) from the diploid population. Loaches from a diploid–polyploid population, and one female (F2) from the diploid population were characterized by at least one chromosome pair with 5S and 28S overlapping signals. The fishes differed mainly in their number of 28S rDNA loci, located on 3–6 chromosomes. All individuals from both populations were characterized by one acrocentric chromosome bearing a 28S rDNA signal on the telomeres of its long arm. The number of major ribosomal DNA in the karyotype of C. taenia by FISH was always higher than the number of Ag-NORs. Our data confirm the extensive polymorphism of NORs in both populations, as already has been observed in closely related Cobitis species, and less polymorphic 5S rDNA pattern. However, this preliminary result highlights the need for a wider scale study.     

Fluoxetine results in misleading conclusions on fish behavior

Fluoxetine is an antidepressant medicine causing relaxation and mood improvement in people, with silencing certain personality traits in some cases. The question arise if such phenomena can be observed in nontarget organisms such as fish. Fluoxetine affects fishes behavior; however, it is not known if the medicine affects its “personality.” This study aimed to evaluate the reaction of the invasive Neogobius fluviatilis and native Gobio gobio individuals to fluoxetine at environmental concentration of 360 ng/L. We prepared three variants of the experiments: (a) behavioral trials with unexposed fishes, (b) behavioral trials with the same fishes after 21 days of fluoxetine exposure, and (c) behavioral trials with the same fishes after 21‐day depuration period, that is, without fluoxetine. The fishes reaction time (RT), that is, difference in time spent on reaching food with and without the necessity of overcoming the obstacle, was analyzed. Additionally, the personality, bold or shy, traits of each fish individual, was assigned. The results indicated that environmental concentrations of the antidepressant influenced RT. The average RT of the fishes cultured with fluoxetine was by 7‐min shorter in comparison with the nonexposed control. Share of individuals exposed to fluoxetine assigned as bold raised to 71.4% in comparison with 46.4% in nonexposed control. This sheds new light on wild fishes behavior caught from freshwater. Environmental concentrations of the antidepressant influenced the time of fishes reaction and share individuals assigned as bold. Moreover, 21‐day recovery lasting might be not enough to get fluoxetine effect on fishes.     

Macrozoobenthos of two Antarctic glacial coves: a comparison with non-disturbed bottom areas

There are only few studies on shallow Antarctic benthic communities associated with habitats affected by intense mineral sedimentation inflow. The analysis of macrofaunal communities associated with two shallow, isolated glacial coves was performed in Admiralty Bay (King George Island) and compared with non-disturbed sites. Multivariate analyses (hierarchical classification, nMDS) clearly separated glacial cove communities (two assemblages) from the sites situated outside both basins (two assemblages). The community influenced by the streamflow of glacial discharge of meltwater situated in the area with sandy–clay–silt sediments had a very low species richness, diversity and abundance. It was dominated by eurytopic, motile deposit feeding polychaetes such as Mesospio moorei, Tharyx cincinnatus and Leitoscoloplos kerguelensis as well as the bivalve Yoldia eightsi. The second glacial community of the area located at a grater distance from the outlet of the stream was characterized by sandy–clay–silt and clay–silt deposits and showed also a low diversity and species richness. The most abundant here were peracarid crustaceans, with the dominant opportunistic feeder Cheirimedon femoratus. Community from the non-disturbed area with silty–clay–sand, and silty–sand sediments had higher species richness and diversity. The assemblage of fauna from the sandy bottom has values of those two indexes similar to those found in the disturbed areas.     

Analysis of mercury levels in historical bone material from syphilitic subjects--pilot studies (short report)

The aim of the present work is to study the remains of seven individuals with typical symptoms of tertiary syphilis in terms of mercury content in bones, thereby verifying whether they were subjected to treatment and, if they were, how long their organisms were exposed to toxic mercury fumes. Mercury was used, mainly in the Middle Ages and in the early modern period, as a preventive measure in case of individuals suffering from syphilis, a venereal disease, and also leprosy. Syphilitic patients treated this way should demonstrate increased concentration of mercury in their bones. The skeletons studied in the present work originate from various archaeological sites in southern and north-central Poland. The analyses concerned individuals with diagnosed syphilis as well as healthy individuals who constituted the control group. The analyses were performed by the LA-ICP-MS technique, with the use of laser Nd: YAG, Macro, 266 nm, New Wave, USA, coupled with Spectrometer Elan DRC-e Perkin Elmer, USA. The content analysis of the studied bone material revealed with high probability that the contact method of mercurial treatment was used only in the case of two women from north-central Poland, deceased at the turn of the 15th century at the earliest.     

Study on the influence of cranberry extract ?uravit S·O·S(?) on the properties of uropathogenic Escherichia coli strains, their ability to form biofilm and its antioxidant properties

Consumption of cranberries is known to exert positive health effects, especially against urinary tract infections. For this reason, presumably, they are widely used in folk medicine. Different aspects of cranberry phenolics activity were studied in individual papers but complex study in this matter is missing. The aim of the present study is to provide complex data concerning various aspects of cranberry extract activity. We studied the effects of subinhibitory concentrations of commercially available extract (?uravit S·O·S(?)) against two Escherichia coli strains isolated from urine of patients with pyelonephritis. Additionally the main extract anthocyanins were characterized. The activity of extract against lipid peroxidation and its radical scavenging ability were also assessed. ?uravit S·O·S(?) decreased the hydrophobicity of one of the studied E. coli strains, reduced swimming motility and adhesion to epithelial cells of both studied strains, it also limited the ability of bacteria to form biofilm. Expression of curli was not affected by cranberry extract, the assessment of P fimbriae expression was not reliable due to extract-induced agglutination of erythrocytes. Cranberry extract caused filamentation in both studied E. coli strains. It also showed pronounced antioxidant and radical scavenging properties. The properties of the studied cranberry extract show that it could be effectively used in prevention and/or elimination of urinary tract infections, specially the recurrent ones.     

Socio-economic position and type 2 diabetes risk factors: patterns in UK children of South Asian, black African-Caribbean and white European origin

Background

Socio-economic position (SEP) and ethnicity influence type 2 diabetes mellitus (T2DM) risk in adults. However, the influence of SEP on emerging T2DM risks in different ethnic groups and the contribution of SEP to ethnic differences in T2DM risk in young people have been little studied. We examined the relationships between SEP and T2DM risk factors in UK children of South Asian, black African-Caribbean and white European origin, using the official UK National Statistics Socio-economic Classification (NS-SEC) and assessed the extent to which NS-SEC explained ethnic differences in T2DM risk factors.

Methods and Findings

Cross-sectional school-based study of 4,804 UK children aged 9–10 years, including anthropometry and fasting blood analytes (response rates 70%, 68% and 58% for schools, individuals and blood measurements). Assessment of SEP was based on parental occupation defined using NS-SEC and ethnicity on parental self-report. Associations between NS-SEC and adiposity, insulin resistance (IR) and triglyceride differed between ethnic groups. In white Europeans, lower NS-SEC status was related to higher ponderal index (PI), fat mass index, IR and triglyceride (increases per NS-SEC decrement [95%CI] were 1.71% [0.75, 2.68], 4.32% [1.24, 7.48], 5.69% [2.01, 9.51] and 3.17% [0.96, 5.42], respectively). In black African-Caribbeans, lower NS-SEC was associated with lower PI (−1.12%; [−2.01, −0.21]), IR and triglyceride, while in South Asians there were no consistent associations between NS-SEC and T2DM risk factors. Adjustment for NS-SEC did not appear to explain ethnic differences in T2DM risk factors, which were particularly marked in high NS-SEC groups.

Conclusions

SEP is associated with T2DM risk factors in children but patterns of association differ by ethnic groups. Consequently, ethnic differences (which tend to be largest in affluent socio-economic groups) are not explained by NS-SEC. This suggests that strategies aimed at reducing social inequalities in T2DM risk are unlikely to reduce emerging ethnic differences in T2DM risk.     

Enterococcus in wound infections: virulence and antimicrobial resistance

Enterococci, a complex group of facultative pathogens have become increasingly isolated in various hospital settings. They are considerable frequently cultured from traumatic and surgical wounds. We investigated 57 strains of the species E. faecalis, E. faecium and E. casseliflavus isolated from infected wounds. Their ability to produce virulence factors and their sensitivity to antibiotics were evaluated using phenotypic and genotyping methods. In the phenotype studies, significant portion of the isolates produced biofilm (66.7%) and gelatinase (36.8%). Nearly 30% of the strains expressed hemolytic properties. Only a few produced DNAse (15.8%) and lipase (7.0%). The genes esp, gelE, cylA, cylB, cylM and agg were detected in most of the isolates (38.6-87.7%). All the isolated enterococci were susceptible to vancomycin and were characterized by their low resistance to antibiotics, except aminoglycosides (HLR).     

Molecular Mechanism of Mutant p53 Stabilization: The Role of HSP70 and MDM2

Numerous p53 missense mutations possess gain-of-function activities. Studies in mouse models have demonstrated that the stabilization of p53 R172H (R175H in human) mutant protein, by currently unknown factors, is a prerequisite for its oncogenic gain-of-function phenotype such as tumour progression and metastasis. Here we show that MDM2-dependent ubiquitination and degradation of p53 R175H mutant protein in mouse embryonic fibroblasts is partially inhibited by increasing concentration of heat shock protein 70 (HSP70/HSPA1-A). These phenomena correlate well with the appearance of HSP70-dependent folding intermediates in the form of dynamic cytoplasmic spots containing aggregate-prone p53 R175H and several molecular chaperones. We propose that a transient but recurrent interaction with HSP70 may lead to an increase in mutant p53 protein half-life. In the presence of MDM2 these pseudoaggregates can form stable amyloid-like structures, which occasionally merge into an aggresome. Interestingly, formation of folding intermediates is not observed in the presence of HSC70/HSPA8, the dominant-negative K71S variant of HSP70 or HSP70 inhibitor. In cancer cells, where endogenous HSP70 levels are already elevated, mutant p53 protein forms nuclear aggregates without the addition of exogenous HSP70. Aggregates containing p53 are also visible under conditions where p53 is partially unfolded: 37°C for temperature-sensitive variant p53 V143A and 42°C for wild-type p53. Refolding kinetics of p53 indicate that HSP70 causes transient exposure of p53 aggregate-prone domain(s). We propose that formation of HSP70- and MDM2-dependent protein coaggregates in tumours with high levels of these two proteins could be one of the mechanisms by which mutant p53 is stabilized. Moreover, sequestration of p73 tumour suppressor protein by these nuclear aggregates may lead to gain-of-function phenotypes.     

Mitochondrial Dysfunction in Pten Haplo-Insufficient Mice with Social Deficits and Repetitive Behavior: Interplay between Pten and p53

Etiology of aberrant social behavior consistently points to a strong polygenetic component involved in fundamental developmental pathways, with the potential of being enhanced by defects in bioenergetics. To this end, the occurrence of social deficits and mitochondrial outcomes were evaluated in conditional Pten (Phosphatase and tensin homolog) haplo-insufficient mice, in which only one allele was selectively knocked-out in neural tissues. Pten mutations have been linked to Alzheimer's disease and syndromic autism spectrum disorders, among others. By 4-6 weeks of age, Pten insufficiency resulted in the increase of several mitochondrial Complex activities (II-III, IV and V) not accompanied by increases in mitochondrial mass, consistent with an activation of the PI3K/Akt pathway, of which Pten is a negative modulator. At 8-13 weeks of age, Pten haplo-insufficient mice did not show significant behavioral abnormalities or changes in mitochondrial outcomes, but by 20-29 weeks, they displayed aberrant social behavior (social avoidance, failure to recognize familiar mouse, and repetitive self-grooming), macrocephaly, increased oxidative stress, decreased cytochrome c oxidase (CCO) activity (50%) and increased mtDNA deletions in cerebellum and hippocampus. Mitochondrial dysfunction was the result of a downregulation of p53-signaling pathway evaluated by lower protein expression of p21 (65% of controls) and the CCO chaperone SCO2 (47% of controls), two p53-downstream targets. This mechanism was confirmed in Pten-deficient striatal neurons and, HCT 116 cells with different p53 gene dosage. These results suggest a unique pathogenic mechanism of the Pten-p53 axis in mice with aberrant social behavior: loss of Pten (via p53) impairs mitochondrial function elicited by an early defective assembly of CCO and later enhanced by the accumulation of mtDNA deletions. Consistent with our results, (i) SCO2 deficiency and/or CCO activity defects have been reported in patients with learning disabilities including autism and (ii) mutated proteins in ASD have been found associated with p53-signaling pathways.