Detection of oncogenic virus genomes and gene products in lung carcinoma

We investigated a series of 122 cases of small cell lung carcinomas and non-small cell lung carcinomas for the presence of several viruses that are known to be oncogenic in humans. Thus, viral genomes (DNA) and/or RNA transcripts and/or proteins of human papillomaviruses (HPV) 16, 18, 31, 33, 51, Epstein–Barr virus (EBV), human herpesvirus 8 (HHV-8), human cytomegalovirus (HCMV) and simian virus 40 (SV40) were investigated on tissue sections (prepared in tissue microarrays) with different techniques of immunohistochemistry and in situ hybridisation. None of the cases displayed a single positive tumour cell for all the viruses tested whatever the technique applied. Of note, in five cases of tumours with lymphoid infiltrates, we detected scattered EBV (EBER)-positive bystander lymphocytes. In three cases, a faint nuclear staining was found with the anti-latent nuclear antigen/LANA1 (HHV-8) antibody. These cases were checked by PCR with two sets of primers (orf 26 and orf 75) and remained negative for this latter virus. Taken together, our data strongly suggest that the conventional human oncogenic viruses (HPV, EBV, HCMV, HHV-8 and SV40) are unlikely to play some role in the development of lung carcinomas

Сетевая система контроля технологического процесса выращивания полупроводниковых кристаллов и тонких пленок

Экспериментальное моделирование аппаратно-программного обеспечения показало достаточную надежность работы системы и значительное уменьшение трудоемкости контроля и управления параметрами технологического процесса

Semen CD4+ T cells and macrophages are productively infected at all stages of SIV infection in macaques.

International audienceThe mucosal events of HIV transmission have been extensively studied, but the role of infected cells present in the genital and rectal secretions, and in the semen, in particular, remains a matter of debate. As a prerequisite to a thorough in vivo investigation of the early transmission events through infected cells, we characterized in detail by multi-parameter flow cytometry the changes in macaque seminal leukocytes during SIVmac251 infection, focusing on T cells, macrophages and dendritic cells. Using immunocytofluorescence targeting SIV proteins and real-time quantitative PCR targeting SIV DNA, we investigated the nature of the infected cells on sorted semen leukocytes from macaques at different stages of infection. Finally, we cocultured semen CD4(+) T cells and macrophages with a cell line permissive to SIV infection to assess their infectivity in vitro. We found that primary infection induced strong local inflammation, which was associated with an increase in the number of leukocytes in semen, both factors having the potential to favor cell-associated virus transmission. Semen CD4(+) T cells and macrophages were productively infected at all stages of infection and were infectious in vitro. Lymphocytes had a mucosal phenotype and expressed activation (CD69 & HLA-DR) and migration (CCR5, CXCR4, LFA-1) markers. CD69 expression was increased in semen T cells by SIV infection, at all stages of infection. Macrophages predominated at all stages and expressed CD4, CCR5, MAC-1 and LFA-1. Altogether, we demonstrated that semen contains the two major SIV-target cells (CD4+ T cells and macrophages). Both cell types can be productively infected at all stages of SIV infection and are endowed with markers that may facilitate transmission of infection during sexual exposure

HIV-1 Efficient Entry in Inner Foreskin Is Mediated by Elevated CCL5/RANTES that Recruits T Cells and Fuels Conjugate Formation with Langerhans Cells

Male circumcision reduces acquisition of HIV-1 by 60%. Hence, the foreskin is an HIV-1 entry portal during sexual transmission. We recently reported that efficient HIV-1 transmission occurs following 1 h of polarized exposure of the inner, but not outer, foreskin to HIV-1-infected cells, but not to cell-free virus. At this early time point, Langerhans cells (LCs) and T-cells within the inner foreskin epidermis are the first cells targeted by the virus. To gain in-depth insight into the molecular mechanisms governing inner foreskin HIV-1 entry, foreskin explants were inoculated with HIV-1-infeceted cells for 4 h. The chemokine/cytokine milieu secreted by the foreskin tissue, and resulting modifications in density and spatial distribution of T-cells and LCs, were then investigated. Our studies show that in the inner foreskin, inoculation with HIV-1-infected cells induces increased CCL5/RANTES (1.63-fold) and decreased CCL20/MIP-3-alpha (0.62-fold) secretion. Elevated CCL5/RANTES mediates recruitment of T-cells from the dermis into the epidermis, which is blocked by a neutralizing CCL5/RANTES Ab. In parallel, HIV-1-infected cells mediate a bi-phasic modification in the spatial distribution of epidermal LCs: attraction to the apical surface at 1 h, followed by migration back towards the basement membrane later on at 4 h, in correlation with reduced CCL20/MIP-3-alpha at this time point. T-cell recruitment fuels the continuous formation of LC-T-cell conjugates, permitting the transfer of HIV-1 captured by LCs. Together, these results reveal that HIV-1 induces a dynamic process of immune cells relocation in the inner foreskin that is associated with specific chemokines secretion, which favors efficient HIV-1 entry at this site

Interplay between Synaptonemal Complex, Homologous Recombination, and Centromeres during Mammalian Meiosis

The intimate synapsis of homologous chromosome pairs (homologs) by synaptonemal complexes (SCs) is an essential feature of meiosis. In many organisms, synapsis and homologous recombination are interdependent: recombination promotes SC formation and SCs are required for crossing-over. Moreover, several studies indicate that initiation of SC assembly occurs at sites where crossovers will subsequently form. However, recent analyses in budding yeast and fruit fly imply a special role for centromeres in the initiation of SC formation. In addition, in budding yeast, persistent SC–dependent centromere-association facilitates the disjunction of chromosomes that have failed to become connected by crossovers. Here, we examine the interplay between SCs, recombination, and centromeres in a mammal. In mouse spermatocytes, centromeres do not serve as SC initiation sites and are invariably the last regions to synapse. However, centromeres are refractory to de-synapsis during diplonema and remain associated by short SC fragments. Since SC–dependent centromere association is lost before diakinesis, a direct role in homolog segregation seems unlikely. However, post–SC disassembly, we find evidence of inter-centromeric connections that could play a more direct role in promoting homolog biorientation and disjunction. A second class of persistent SC fragments is shown to be crossover-dependent. Super-resolution structured-illumination microscopy (SIM) reveals that these structures initially connect separate homolog axes and progressively diminish as chiasmata form. Thus, DNA crossing-over (which occurs during pachynema) and axis remodeling appear to be temporally distinct aspects of chiasma formation. SIM analysis of the synapsis and crossover-defective mutant Sycp1−/− implies that SCs prevent unregulated fusion of homolog axes. We propose that SC fragments retained during diplonema stabilize nascent bivalents and help orchestrate local chromosome reorganization that promotes centromere and chiasma function

Barcoding a Quantified Food Web: Crypsis, Concepts, Ecology and Hypotheses

The efficient and effective monitoring of individuals and populations is critically dependent on correct species identification. While this point may seem obvious, identifying the majority of the more than 100 natural enemies involved in the spruce budworm (Choristoneura fumiferana – SBW) food web remains a non-trivial endeavor. Insect parasitoids play a major role in the processes governing the population dynamics of SBW throughout eastern North America. However, these species are at the leading edge of the taxonomic impediment and integrating standardized identification capacity into existing field programs would provide clear benefits. We asked to what extent DNA barcoding the SBW food web would alter our understanding of the diversity and connectence of the food web and the frequency of generalists vs. specialists in different forest habitats. We DNA barcoded over 10% of the insects collected from the SBW food web in three New Brunswick forest plots from 1983 to 1993. For 30% of these specimens, we amplified at least one additional nuclear region. When the nodes of the food web were estimated based on barcode divergences (using molecular operational taxonomic units (MOTU) or phylogenetic diversity (PD) – the food web became much more diverse and connectence was reduced. We tested one measure of food web structure (the “bird feeder effect”) and found no difference compared to the morphologically based predictions. Many, but not all, of the presumably polyphagous parasitoids now appear to be morphologically-cryptic host-specialists. To our knowledge, this project is the first to barcode a food web in which interactions have already been well-documented and described in space, time and abundance. It is poised to be a system in which field-based methods permit the identification capacity required by forestry scientists. Food web barcoding provided an effective tool for the accurate identification of all species involved in the cascading effects of future budworm outbreaks. Integrating standardized barcodes within food webs may ultimately change the face of community ecology. This will be most poignantly felt in food webs that have not yet been quantified. Here, more accurate and precise connections will be within the grasp of any researcher for the first time

Limbic hyperconnectivity in the vegetative state.

OBJECTIVE: To investigate functional connectivity between the default mode network (DMN) and other networks in disorders of consciousness. METHODS: We analyzed MRI data from 11 patients in a vegetative state and 7 patients in a minimally conscious state along with age- and sex-matched healthy control subjects. MRI data analysis included nonlinear spatial normalization to compensate for disease-related anatomical distortions. We studied brain connectivity data from resting-state MRI temporal series, combining noninferential (independent component analysis) and inferential (seed-based general linear model) methods. RESULTS: In DMN hypoconnectivity conditions, a patient's DMN functional connectivity shifts and paradoxically increases in limbic structures, including the orbitofrontal cortex, insula, hypothalamus, and the ventral tegmental area. CONCLUSIONS: Concurrently with DMN hypoconnectivity, we report limbic hyperconnectivity in patients in vegetative and minimally conscious states. This hyperconnectivity may reflect the persistent engagement of residual neural activity in self-reinforcing neural loops, which, in turn, could disrupt normal patterns of connectivity

Thresholds for the perception of hand-transmitted vibration: dependence on contact area and contact location

The detection of vibration applied to the glabrous skin of the hand varies with contact conditions. Three experiments have been conducted to relate variations in the perception of hand-transmitted vibration to previously reported properties of tactile channels. The effects of a surround around the area of contact, the size of the area of contact, the location of the area of contact, the contact force, and the hand posture on perception of thresholds were determined for 8–500?Hz vibration. Removal of a surround around a contact area on the fingertip elevated thresholds of the NP II channel (FA I fibres) at frequencies less than 31.5?Hz and reduced thresholds of the Pacinian channel (FA II fibres) at frequencies greater than about 63?Hz. When no surround was present, thresholds reduced systematically as the contact area increased from the fingertip to the whole hand at frequencies from 16 to 125?Hz, although the decrease was not inversely proportional to the increase in contact area. The results are partly explained by spatial summation in the Pacinian channel (FA II fibres) and the involvement of the NP II channel (SA II) with some influence of biodynamic responses and contact pressures. There were regional differences in sensitivity over the hand within the NP I channel but not within the Pacinian channel: the NP I thresholds (less than 31.5?Hz) decreased from proximal to distal regions of the hand, whereas the Pacinian thresholds (125?Hz) were independent of contact location over the hand