Characterization of human intestinal bifidobacteria using competitive PCR and PCR-TTGE

In this study, a competitive PCR was developed to estimate the quantity of bifidobacteria in human faecal samples using two 16S rRNA gene Bifidobacterium genus-specific primers, Bif164f and Bif662r. A PCR-temporal temperature gradient gel electrophoresis (TTGE) with the same primers also allowed us to describe the Bifidobacterium species present in these faecal samples. The PCR product obtained from the competitor had 467 bp, and was 47 bp shorter than the PCR products obtained from Bifidobacterium strains. The number of bifidobacterial cells was linear from 10 to 10(8) cells per PCR assay. Taking into account the dilutions of the extracted DNA, the linear range was over 8 x 10(5) bifidobacteria g(-1) of faeces. Reproducibility was assessed from 10 independent DNA extractions from the same stool and the coefficient of variation was 0.5%. When the competitive PCR was compared with the culture method, a similar count of seven out of nine Bifidobacterium pure cultures were obtained, or had a difference inferior or equal to 1 log(10). In faecal samples, the enumeration of Bifidobacterium genus in most cases gave higher results with competitive PCR than with culture on selective Columbia-Beerens agar pH 5 (P < 0.05). In conclusion, this competitive PCR allows a rapid, highly specific and reproducible quantification of Bifidobacterium genus in faecal samples. TTGE fragments co-migrating with B. longum CIP64.63 fragment were found in 10 out of 11 faecal samples. Bifidobacterium adolescentis and B. bifidum were detected in five out of 11 subjects. Thus, cPCR and PCR-TTGE can be associated in order to characterize human faecal bifidobacteria.     

Macrophage mesenchymal migration requires podosome stabilization by filamin A

Filamin A (FLNa) is a cross-linker of actin filaments and serves as a scaffold protein mostly involved in the regulation of actin polymerization. It is distributed ubiquitously, and null mutations have strong consequences on embryonic development in humans, with organ defects which suggest deficiencies in cell migration. We have reported previously that macrophages, the archetypal migratory cells, use the protease- and podosome-dependent mesenchymal migration mode in dense three-dimensional environments, whereas they use the protease- and podosome-independent amoeboid mode in more porous matrices. Because FLNa has been shown to localize to podosomes, we hypothesized that the defects seen in patients carrying FLNa mutations could be related to the capacity of certain cell types to form podosomes. Using strategies based on FLNa knock-out, knockdown, and rescue, we show that FLNa (i) is involved in podosome stability and their organization as rosettes and three-dimensional podosomes, (ii) regulates the proteolysis of the matrix mediated by podosomes in macrophages, (iii) is required for podosome rosette formation triggered by Hck, and (iv) is necessary for mesenchymal migration but dispensable for amoeboid migration. These new functions assigned to FLNa, particularly its role in mesenchymal migration, could be directly related to the defects in cell migration described during the embryonic development in FLNa-defective patients.     

Onset and early use of gestural communication in nonhuman great apes

The early gesturing of six bonobos, eight chimpanzees, three gorillas, and eight orangutans was systematically documented using focal animal sampling. Apes' were observed during their first 20 months of life in an effort to investigate: (i) the onset of gesturing; (ii) the order in which signals of different sensory modalities appear; (iii) the extent to which infants make use of these modalities in their early signaling; and (iv) the behavioral contexts where signals are employed. Orangutans differed in important gestural characteristics to African ape species. Most notably, they showed the latest gestural onset and were more likely to use their early signals in food-related interactions. Tactile and visual signals appeared similarly early across all four species. In African apes, however, visual signaling gained prominence over time while tactile signaling decreased. These findings suggest that motor ability, which encourages independence from caregivers, is an important antecedent, among others, in gestural onset and development, a finding which warrants further investigation.     

Polar invasion and translocation of Neisseria meningitidis and Streptococcus suis in a novel human model of the blood-cerebrospinal fluid barrier

Acute bacterial meningitis is a life-threatening disease in humans. Discussed as entry sites for pathogens into the brain are the blood-brain and the blood-cerebrospinal fluid barrier (BCSFB). Although human brain microvascular endothelial cells (HBMEC) constitute a well established human in vitro model for the blood-brain barrier, until now no reliable human system presenting the BCSFB has been developed. Here, we describe for the first time a functional human BCSFB model based on human choroid plexus papilloma cells (HIBCPP), which display typical hallmarks of a BCSFB as the expression of junctional proteins and formation of tight junctions, a high electrical resistance and minimal levels of macromolecular flux when grown on transwell filters. Importantly, when challenged with the zoonotic pathogen Streptococcus suis or the human pathogenic bacterium Neisseria meningitidis the HIBCPP show polar bacterial invasion only from the physiologically relevant basolateral side. Meningococcal invasion is attenuated by the presence of a capsule and translocated N. meningitidis form microcolonies on the apical side of HIBCPP opposite of sites of entry. As a functionally relevant human model of the BCSFB the HIBCPP offer a wide range of options for analysis of disease-related mechanisms at the choroid plexus epithelium, especially involving human pathogens.     

Sex differences in the neural mechanisms mediating addiction: a new synthesis and hypothesis

In this review we propose that there are sex differences in how men and women enter onto the path that can lead to addiction. Males are more likely than females to engage in risky behaviors that include experimenting with drugs of abuse, and in susceptible individuals, they are drawn into the spiral that can eventually lead to addiction. Women and girls are more likely to begin taking drugs as self-medication to reduce stress or alleviate depression. For this reason women enter into the downward spiral further along the path to addiction, and so transition to addiction more rapidly. We propose that this sex difference is due, at least in part, to sex differences in the organization of the neural systems responsible for motivation and addiction. Additionally, we suggest that sex differences in these systems and their functioning are accentuated with addiction. In the current review we discuss historical, cultural, social and biological bases for sex differences in addiction with an emphasis on sex differences in the neurotransmitter systems that are implicated.     

Standardization efforts of digital pathology in Europe

BACKGROUND: EURO-TELEPATH is a European COST Action IC0604. It started in 2007 and will end in November 2011. Its main objectives are evaluating and validating the common technological framework and communication standards required to access, transmit, and manage digital medical records by pathologists and other medical specialties in a networked environment. BUSINESS MODELLING: Working Group 1, "Business Modelling in Pathology," has designed main pathology processes - Frozen Study, Formalin Fixed Specimen Study, Telepathology, Cytology, and Autopsy - using Business Process Modelling Notation (BPMN). INFORMATICS STANDARDS IN PATHOLOGY: Working Group 2 has been dedicated to promoting the application of informatics standards in pathology, collaborating with Integrating Healthcare Enterprise (IHE), Digital Imaging and Communications in Medicine (DICOM), Health Level Seven (HL7), and other standardization bodies. CONCLUSIONS: Health terminology standardization research has become a topic of great interest. Future research work should focus on standardizing automatic image analysis and tissue microarrays imaging.