Cell adhesion to low-Mr proteins extractable from mineralized and soft connective tissues.

Guanidinium chloride (4 M) containing proteinase inhibitors was used to extract proteins from porcine calvariae and long bones. The extracted proteins were separated on polyacrylamide slab gels and transferred electrophoretically to nitrocellulose strips. Proteins with cell-adhesion properties were identified by incubating the strips with cells and staining with Amido Black. In addition to binding to fibronectin, both bone cells and fibroblast-like cells adhered to proteins of Mr approximately 30 000 and approximately 14 000-17 000. 4 M-Guanidinium chloride extracts of porcine skin and gingiva yielded cell-binding proteins with similar Mr values. These data suggest that these low-Mr proteins may have a general cell-adhesion function in both soft and mineralized connective tissues.     

How do king penguins (Aptenodytes patagonicus apply the mathematical theory of information to communicate in windy conditions?

In the king penguin (Aptenodytes patagonicus), both pair members alternate in incubating and rearing their chick. Mates can recognize each other among thousands of other birds in the hubbub of the colony using only acoustic signalling: the display call. Large penguin colonies are found on sub-Antarctic islands where strong winds blow throughout the year. We have shown by experiments under natural conditions that the level of background noise increases in windy conditions and thus leads to a diminution of the signal-to-noise ratio. Moreover the emergence level of the signal revealed by entropy calculation is statistically weaker in windy conditions. To achieve breeding success, birds must continue communicating in spite of the significant decrease in the total amount of information that can be transmitted in windy situations. For the first time, to our knowledge, we have shown that a bird species takes into account the constraints imposed by wind on their acoustic communication. In windy conditions, birds try to maintain the efficiency of communication by increasing both the number of calls emitted and the number of syllables per call. This result conforms with predictions from the mathematical theory of communication: increased redundancy in a signal improves the probability of receiving a message in a noisy channel.     

Online Training on Skin Cancer Diagnosis in Rheumatologists: Results from a Nationwide Randomized Web-Based Survey

Patients with inflammatory rheumatisms, such as rheumatoid arthritis, are more prone to develop skin cancers than the general population, with an additional increased incidence when receiving TNF blockers. There is therefore a need that physicians treating patients affected with inflammatory rheumatisms with TNF blockers recognize malignant skin lesions, requiring an urgent referral to the dermatologist and a potential withdrawal or modification of the immunomodulatory treatment. We aimed to demonstrate that an online training dedicated to skin tumors increase the abilities of rheumatologists to discriminate skin cancers from benign skin tumors. A nationwide randomized web-based survey involving 141 French rheumatologists was conducted. The baseline evaluation included short cases with skin lesion pictures and multiple choice questions assessing basic knowledge on skin cancers. For each case, rheumatologists had to indicate the nature of skin lesion (benign; premalignant/malignant), their level of confidence in this diagnosis (10-points Likert scale), and the precise dermatological diagnosis among 5 propositions. Different scores were established. After randomization, only one group had access to the online formation consisting in 4 e-learning modules on skin tumors, of 15 minutes each (online training group). After reevaluation, the trained and the non-trained group (control group) were compared. The primary end-point was the number of adequate diagnoses of the nature of the skin lesions. The mean number of adequate diagnosis for the benign versus premalignant/malignant nature of the lesions was higher in the online training group (13.4 vs. 11.2 points; p value <0.0001). While the other knowledge scores were also significantly higher, no statistical difference was observed on the level of self-confidence between the 2 groups. In conclusion, the online formation was effective to improve the rheumatologists’ ability to diagnose skin cancer.     

Unsuspected effects of a lung-specific Cre deleter mouse line

Cre-expressing mouse lines constitute an important asset to mammalian genetics, allowing the deletion of genes in a spatio-temporal specific manner. Our study on Hox gene function in lung development has led us to use a lung endoderm-specific deletion with the Sftpc-cre mouse line expressing the Cre recombinase gene under the control of human surfactant protein C regulatory sequences. In control experiments, the Cre recombinase faithfully activated the Rosa26-lacZ reporter gene in lung epithelium. However as early as e15.5, lungs from Sftp-Cre(+) embryos showed abnormal dilated cysts. This unexpected phenotype was also observed in mice carrying the conditional lung epithelial Hoxa5 deletion, indicating some bias due to Cre deleterious effects. Excessive apoptosis, likely due to Cre toxicity, could explain the abnormal cysts. Our findings illustrate the need for appropriate control experiments and careful interpretation of data to discriminate between the phenotype due to the targeted mutation and the confounding effects of the Cre recombinase.     

Combining ecosystem indicators and life cycle assessment for environmental assessment of demersal trawling in Tunisia

The International Journal of Life Cycle Assessment - The present study assesses environmental performance of seafood production by demersal trawling in Tunisia (Gulf of Gabes) in order to analyze...     

Morphological versus acoustic analysis: what is the most efficient method for sexing yelkouan shearwaters Puffinus yelkouan?

Sexing monomorphic seabirds is particularly difficult, and available methods have various disadvantages, such as seasonal non-applicability or stress induction. The yelkouan shearwater Puffinus yelkouan is a poorly studied seabird endemic to the Mediterranean basin. Ecological and biological data are needed for this species, thus necessitating the development of appropriate field methods. Here, we tested two methods for sexing yelkouan shearwaters: the classical morphological method and a new acoustic method. Morphological analysis demonstrated sexual differences in head, leg and feather measurements, with a high degree of overlap resulting in only 87.2% accuracy. In contrast, acoustic analysis showed that the highest value of the fundamental frequency (FC) and duration of the clear note of calls did not overlap between males and females. Yelkouan shearwaters can be sexed with 100% accuracy by measuring FC. If FC < 678.4 Hz, the bird is female, while if FC > 678.4 Hz, the bird is male. Other advantages of this method are its simplicity and non-invasiveness, which are particularly important for a potentially threatened species.     

Genotypic Prediction of Tropism of Highly Diverse HIV-1 Strains from Cameroon

Background

The use of CCR5 antagonists involves determination of HIV-1 tropism prior to initiation of treatment. HIV-1 tropism can be assessed either by phenotypic or genotypic methods. Genotypic methods are extensively used for tropism prediction. However, their validation in predicting tropism of viral isolates belonging to group M non-B subtypes remains challenging. In Cameroon, the genetic diversity of HIV-1 strains is the broadest reported worldwide. To facilitate the integration of CCR5 antagonists into clinical practice in this region, there is a need to evaluate the performance of genotypic methods for predicting tropism of highly diverse group M HIV-1 strains.

Methods

Tropism of diverse HIV-1 strains isolated from PBMCs from Cameroon was determined using the GHOST cell assay. Prediction, based on V3 sequences from matched plasma samples, was determined using bioinformatics algorithms and rules based on position 11/25 and net charge applied independently or combined according to Delobel''s and Garrido''s rules. Performance of genotypic methods was evaluated by comparing prediction generated with tropism assigned by the phenotypic assay.

Results

Specificity for predicting R5-tropic virus was high, ranging from 83.7% to 97.7% depending on the genotypic methods used. Sensitivity for X4-tropic viruses was fairly low, ranging from 33.3% to 50%. In our study, overall, genotypic methods were less able to accurately predict X4-tropic virus belonging to subtype CRF02_AG. In addition, it was found that of the methods we used the Garrido rule has the highest sensitivity rate of over 50% with a specificity of 93%.

Conclusion

Our study demonstrated that overall, genotypic methods were less sensitive for accurate prediction of HIV-1 tropism in settings where diverse HIV-1 strains co-circulate. Our data suggest that further optimization of genotypic methods is needed and that larger studies to determine their utility for tropism prediction of diverse HIV-1 strains may be warranted.