Analysis of MC1R genetic variation in Lepus species in Mediterranean refugia

A study on the inter- and intraspecies variation of MC1R gene was performed in Lepus species inhabiting the Mediterranean basin (L. granatansis, L. europaeus, L. corsicanus, L. castroviejoi and L. mediterraneus) and their neighboring species in Europe (L. timidus) and Africa (L. saxatilis, L. capensis), in order to infer micro- versus macroevolutionary adaptation. Eleven different sequences were isolated that corresponded to five amino acid sequences. Comparison of MC1R nucleotide phylogenetic tree with phylogenies resulting from mtDNA regions of the same species showed absence of congruence between these sets of markers. The Mediterranean area that offered refugia during last glaciation retains more MC1R genotypes compared with populations of North and Central Europe as a consequence of founder effects. L. corsicanus and L. castroviejoi bore identical alleles supportive of their conspecificity, as indicated by other molecular markers. Within L. europaeus, a group of Israeli hares were distinguished by a different MC1R functional allele; additional differences in coat colour and other genetic markers raise doubts about its taxonomic status. Finally, the present data reinforced the idea of bi-directional introgressive hybridization between L. europaeus and L. timidus in Switzerland.     

Serotonin inhibition of tumor necrosis factor-alpha synthesis by human monocytes

Serotonin inhibited in a concentration dependent way (10(-3) M to 10(-10) M) the LPS induced Tumor Necrosis Factor-alpha synthesis both, when added to the monocyte cultures from the beginning and when added together with the activating stimulus 8 hours before the end of the culture. The inhibitory effect was specifically blocked by the 5-HT1 and 5-HT2 serotonin antagonist methysergide and the 5-HT2 receptor antagonist ketanserin. This indicates that only the 5-HT2 receptor family (5-HT2 or 5-HT1C) may be involved in the inhibitory effect. Serotonin seems to play an important immunomodulatory role in macrophage functions.     

Numerical analysis of electrophoretic protein patterns of Providencia stuartii strains from urine, wound and other clinical sources

Eighty-six strains of Providencia stuartii (mainly of human origin) were characterized by one-dimensional SDS-PAGE of cellular proteins. The strains came from various countries; 52 were from urine, 11 from wounds, five from blood (one of these also from urine), four from ear infections, two each from faeces and sputum, one from 'alimentation'and nine from unknown sources. The protein patterns, which contained 45 to 50 discrete bands, were highly reproducible. The patterns of 46 Prov, stuartii strains (selected to represent the full range of protein pattern diversity) plus those of the type strains of the four other Providencia species were used as the basis for two numerical analyses. In the first, which included all the protein bands, the Prov. stuartii strains formed 13 clusters at the 88% S level. In the second analysis, in which the principal protein bands (in the 33.8–40.7 kDa range) were excluded, 45 of the 46 Prov. stuartii strains formed a single cluster at the 82% S level, whilst the four Providencia reference strains remained unclustered. The 40 strains of Prov. stuartii not included in the cluster analysis were assigned to a protein type by calculating their similarity with the strains in the database used for the cluster analysis. We conclude that high resolution PAGE combined with computerized analysis of protein patterns provides the basis for typing clinical strains of Prov. stuartii . Reference strains of each of the 13 PAGE types identified are available from NCTC for inclusion in future studies.     

Localized conformational changes trigger the pH-induced fibrillogenesis of an amyloidogenic λ light chain protein

Solvent conditions modulate the expression of the amyloidogenic potential of proteins. In this work the effect of pH on the fibrillogenic behavior and the conformational properties of 6aJL2, a model protein of the highly amyloidogenic variable light chain λ6a gene segment, was examined. Ordered aggregates showing the ultrastructural and spectroscopic properties observed in amyloid fibrils were formed in the 2.0–8.0?pH range. At pH <3.0 a drastic decrease in lag time and an increase in fibril formation rate were found. In the 4.0–8.0?pH range there was no spectroscopic evidence for significant conformational changes in the native state. Likewise, heat capacity measurements showed no evidence for residual structure in the unfolded state. However, at pH <3.0 stability is severely decreased and the protein suffers conformational changes as detected by circular dichroism, tryptophan and ANS fluorescence, as well as by NMR spectroscopy. Molecular dynamics simulations indicate that acid-induced conformational changes involve the exposure of the loop connecting strands E and F. These results are compatible with pH-induced changes in the NMR spectra. Overall, the results indicate that the mechanism involved in the acid-induced increase in the fibrillogenic potential of 6aJL2 is profoundly different to that observed in κ light chains, and is promoted by localized conformational changes in a region of the protein that was previously not known to be involved in acid-induced light chain fibril formation. The identification of this region opens the potential for the design of specific inhibitors.     

Development of a Cotton Honey-Based Spread by Controlling Compositional and Processing Parameters

Food Biophysics - Honey from cotton blossoms tends to crystallize rapidly resulting in a product with hard texture and low spreadability, even if it is processed via a controlled crystallization...     

Are human progestagens among the causes of amphibian extinction?

We hypothesised that massive elimination of human and animal progestagens through wastewater can be toxic for reproduction of amphibians. Several medical test using amphibian bioassays (i.e. Hogben test) have demonstrated that human chorionic gonadotropin is toxic for amphibians. Nowadays, a huge amount of sexual hormones from women, animal farms and aquaculture arrive to inland water systems and could be a cause of amphibians extinction.     

Numerical analysis of electrophoretic protein patterns of Providencia alcalifaciens strains from human faeces and veterinary specimens

Twenty-five strains of Providencia alcalifaciens from various countries have been characterized by one-dimensional SDS-PAGE of cellular proteins. They comprised 15 from human faeces, one from duck faeces, one from a guinea-pig eye and eight from unknown sources. Also included, for reference purposes, were the type strains of three other Providencia species. The protein patterns, which contained 45-50 discrete bands, were highly reproducible and were used as the basis for two numerical analyses. In the first, in which the principal protein bands (in the 33-40 kD range) were excluded, the 25 Prov. alcalifaciens strains formed, at the 83% S level, a single cluster whilst the three Providencia reference strains remained unclustered. In the second, which included all the protein bands, the 25 Prov. alcalifaciens strains formed 10 clusters at the 85% S level. We conclude that high resolution PAGE combined with computerized analysis of protein patterns provides the basis for typing clinical strains of Prov. alcalifaciens. Reference strains of each of the 10 PAGE types identified are available from NCTC for inclusion in future studies.     

The Obesity Epidemic and Future Emergency Responders

Emergency responders should be fit to safely perform strenuous duties. In particular, young recruits are expected to be at or near peak career fitness. We studied the prevalence and health associations of excess weight among 370 consecutive emergency responder candidates for fire and ambulance services in Massachusetts. The mean age and BMI of the recruits were 26.3 (3.8) years and 28.5 (4.9) kg/m², respectively. Seventy‐seven percent had BMI ≥25 kg/m², and 33% were obese (BMI ≥30 kg/m²). After multivariate adjustment, both higher BMI categories and unit increases in BMI were significantly associated with higher blood pressures, worse metabolic profiles, and lower exercise tolerance. Excess weight is highly prevalent and associated with elevated cardiovascular risk among future emergency responders. These findings in a population expected to perform demanding duties supporting public safety merit prompt public health intervention.     

Polarization‐dependent second‐harmonic generation for collagen‐based differentiation of breast cancer samples

Nonlinear optical imaging techniques have been widely used to reveal biological structures for accurate diagnosis at the cellular as well as the tissue level. In the present study, polarization‐dependent second‐harmonic generation (PSHG) was used to determine collagen orientation in breast cancer biopsy tissues (grades 0, I, II and III). The obtained data were processed using fast Fourier transform (FFT) analysis, while second‐harmonic generation (SHG) anisotropy and the “ratio parameter” values were also calculated. Such measurements were shown to be able to distinguish collagen structure modifications in different cancer grades tested. The analysis presented herein suggests that PSHG imaging could provide a quantitative evaluation of the tumor state and the distinction of malignant from benign breast tissues. The obtained results also allowed the development of a biophysical model, which can explain the aforementioned differentiations and is in agreement with the simulations relating the SHG anisotropy values with the mechanical tension applied to the collagen during cancer progression. The current approach could be a step forward for the development of new, nondestructive, label free optical diagnostic tools for cancer reducing the need of recalls and unnecessary biopsies, while potentially improving cancer detection rates.