Cytokine receptor expression in human lymphoid tissue: analysis by fluorescence microscopy

A highly-sensitive flourescence method, capable of detecting cytokine receptors present at low concentrations (around I DO molecules per cell) by flow cytometry, was adapted for use on tissue sections. This method was used to examine the expression of several cytokine receptors in lymphoid ti ss ues. lL-2 receptors were distributed broadly, with higher concentrations in T cell areas. lL-1 receptor Type I was detected in T cell areas and in the follicular mantle, and was strongly expressed on vasc ular endothelium. IL-6 receptor was found at very low concentration, both within and outside germinal centres. The gp 130 molecule, which is involved in the functional receptor complex for IL-6 and several other cytokines, was present at higher concentrations, particularly in the germinal centre. Analysis of receptor expression in secondary lymphoid tissue provides evidence bearing on the physiological roles of cytokines, as these tissues contain cells at various stages of physiological activation located in well-defined functional zones.Heddy Zola, Jodie Ridings, Helen Weedon, Michael Fusco, Roger W. Byard, Peter J. Macardl

Follicle-stimulating hormone signal transduction: Role of carbohydrate in aromatase induction in immature rat Sertoli cells

Receptor activated adenylate cyclase acts as a major transmembrane signalling system. It is widely accepted that upon binding to its receptor, follicle-stimulating hormone (FSH) activates the cAMP-dependent pathway which in turn mediates FSH-induced estradiol production in Sertoli cells. Studies utilizing several chemically derived variants of FSH have demonstrated that these variants bind to the FSH receptors with equal avidity but differ in their ability to activate cAMP-dependent pathways. Since cAMP is believed to be the second messenger responsible for FSH signal transduction, we tested two hypotheses: (1) that the effects of different oFSH variants on cAMP production and aromatase induction (as measured by estradiol production) would be in parallel; and (2) that deglycosylated ovine FSH (DG-oFSH) would antagonize the ability of intact oFSH to stimulate aromatase induction, similar to its reported antagonistic effect on cAMP production.Immature rat (7- to 10-day-old) Sertoli cells were cultured and the effects of several different oFSH variants on cAMP production and/or aromatase induction were tested. The variants tested were native oFSH, DG-oFSH, asialo oFSH (AS-oFSH), a recombinant of intact LH[alpha] and FSH[beta] ([alpha] + [beta]) and a recombinant of deglycosylated LH[alpha] and intact FSH[beta] (DG[alpha] + [beta]). Both native oFSH and [alpha] + [beta] recombinant at relatively large doses (10 ng) elicited a significant increase in extracellular cAMP accumulation as well as total cAMP production. In contrast, DG-oFSH did not produce an increase in cAMP even at 10-fold higher doses than native oFSH. Intracellular cAMP concentrations did not increase following stimulation with native oFSH, DG-oFSH or DG[alpha] + [beta].In contrast to the divergent effects of oFSH and DG-oFSH on cAMP production all variants of oFSH stimulated estradiol production from Sertoli cells albeit with varying potencies. The sensitivity (minimal effective dose) and ED50 (dose at which half maximal response is achieved) of the estradiol (E2) response curve to increasing concentrations of native oFSH were 0.025 +/- 0.01 and 0.33 +/- 0.05 ng, respectively. Asialo-oFSH (AS-oFSH) increased E2 production with a potency (comparative dose required for effect) similar to that of native oFSH. In contrast, there was a 10-fold reduction in potency of DG-oFSH (ED50 of 3.27 +/- 1.7 ng). The efficacy (maximum effect on aromatase induction) of native, DG and AS-oFSH were equipotent. Coincubation of DG-oFSH (0.005-100 ng) with oFSH (0.01-0.625 ng) demonstrated the inductive effects to be additive. In contrast to the reduced potency of DG-oFSH, DG[alpha] -- [beta] recombinants (0.156-160 ng) increased E2 production with a potency similar to that of the native oFSH.Our data suggest: (1) the effects of oFSH variants on cAMP production and aromatase induction are not always parallel; (2) DG-oFSH is a weak agonist and not an antagonist of oFSH-mediated aromatase induction; (3) the reduced potency of DG-oFSH must involve oligosaccharides internal to sialic acid; and (4) depleting the carbohydrate moiety on the [alpha] subunit alone may not be adequate to reduce the potency of oFSH to induce aromatase. Since DG-oFSH does not increase cAMP accumulation, but is able to induce aromatase, the FSH-mediated induction of aromatase may be transduced through other signal pathways. Alternatively, the maximal steroidogenic response may be induced by small, but undetectable, increases in intracellular cAMP concentrations or availability of segregated cAMP pools.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29186/1/0000239.pd

Effect of anion type in the performance of ionic liquid/poly(vinylidene fluoride) electromechanical actuators

Low voltage actuators based on poly(vinylidene fluoride)(PVDF)with 10, 25 and 40 % 1-hexyl-3-methylimidazolium chloride ([C6mim][Cl])and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C6mim][NTf2]) are prepared by solvent casting in order to evaluate the effect of anion size in the bending properties. Independently of the ionic liquid type and content, its presence leads to the crystallization of PVDF in the -phase. The addition of ionic liquid into the polymer matrix decreases significantly its degree of crystallinity and the elastic modulus. It is also confirmed the good miscibility between PVDF and IL,determinedby the interaction of the CF2groups from the PVDF chains with the imidazolium ring in the ionic liquid (IL). The AC conductivity of the composites depends both on the amount of ionic liquid content and anion size. The bending movement of the IL/PVDF composites is correlated to theirdegree of crystallinity, mechanical properties and ionic conductivity value and the best value of bending response (0.53 %) being found for IL/PVDF composite with40 wt% of [C6mim][Cl] at an applied voltage of 10 volts square signal.The authors thank the FCT-Fundação para a Ciência e Tecnologia-for financial support in the framework of the Strategic Funding UID/FIS/04650/2013, projects PTDC/EEI-SII/5582/2014 and PTDC/CTM-ENE/5387/2014,and grants SFRH/BD/90215/2012 (J.C.D.), SFRH/BPD/112547/2015 (C.M.C.). The authors thank Solvay for kindly supplying the high quality materials. Financial support from the Basque Government Industry Department under the ELKARTEK Program is also acknowledged.The authorsexpress their gratitude to the Ministry of the Higher Education and Scientific Research of Tunisiafor a research fellowship

The nuclear matrix protein CIZ1 facilitates localization of Xist RNA to the inactive X-chromosome territory

The nuclear matrix protein Cip1-interacting zinc finger protein 1 (CIZ1) promotes DNA replication in association with cyclins and has been linked to adult and pediatric cancers. Here we show that CIZ1 is highly enriched on the inactive X chromosome (Xi) in mouse and human female cells and is retained by interaction with the RNA-de-pendent nuclear matrix. CIZ1 is recruited to Xi in response to expression of X inactive-specific transcript (Xist) RNA during the earliest stages of X inactivation in embryonic stem cells and is dependent on the C-terminal nuclear matrix anchor domain of CIZ1 and the E repeats of Xist. CIZ1-null mice, although viable, display fully penetrant female-specific lymphoproliferative disorder. Interestingly, in mouse embryonic fibroblast cells derived from CIZ1-null embryos, Xist RNA localization is disrupted, being highly dispersed through the nucleoplasm rather than focal. Focal localization is reinstated following re-expression of CIZ1. Focal localization of Xist RNA is also disrupted in activated B and T cells isolated from CIZ1-null animals, suggesting a possible explanation for female-specific lymphoproliferative disorder. Together, these findings suggest that CIZ1 has an essential role in anchoring Xist to the nuclear matrix in specific somatic lineages

Effect of Multivitamin Supplementation on Measles Vaccine Response among HIV-exposed Uninfected Tanzanian Infants.

Immunization and nutritional interventions are mainstays of child health programs in sub-Saharan Africa, yet few published data exist on their interactions. HIV-exposed (but uninfected) infants enrolled in a randomized placebo-controlled trial of multivitamin supplements (vitamins B complex, C, and E) conducted in Tanzania were sampled for an assessment of measles IgG quantity and avidity at 15 to 18 months. Infants were vaccinated between 8.5 and 12 months of age, and all mothers received high-dose multivitamins as the standard of care. Of 201 HIV-exposed infants who were enrolled, 138 (68.7%) were seropositive for measles. There were no effects of infant multivitamin supplementation on measles seroconversion proportions, IgG concentrations, or IgG avidity (P > 0.05). The measles seroconversion proportion was greater for HIV-exposed infants vaccinated at 10 to 11 months of age than for those vaccinated at 8.5 to 10 months (P = 0.032) and greater for infants whose mothers had a CD4 T-cell count of <200 cells/μl than for infants whose mothers had a CD4 T-cell count of >350 cells/μl (P = 0.039). Stunted infants had a significantly decreased IgG quantity compared to nonstunted infants (P = 0.012). As for measles avidity, HIV-exposed infants vaccinated at 10 to 11 months had increased antibody avidity compared to those vaccinated at 8.5 to 10 months (P = 0.031). Maternal CD4 T-cell counts of <200 cells/μl were associated with decreased avidity compared to counts of >350 cells/μl (P = 0.047), as were lower infant height-for-age z-scores (P = 0.016). Supplementation with multivitamins containing B complex, C, and E does not appear to improve measles vaccine responses for HIV-exposed infants. Studies are needed to better characterize the impact of maternal HIV disease severity on the immune system development of HIV-exposed infants and the effect of malnutrition interventions on vaccine responses. (This study has been registered at ClinicalTrials.gov under registration no. NCT00197730.)

“PMA Sounds Fun”: Negotiating Drug Discourses Online

In 2007, a young woman, Annabel Catt, died after consuming a capsule sold as “ecstasy” that contained para-methoxyamphetamine. In this paper, we describe how this death was depicted in online drug-user communities and illustrate how the meanings of drug use are negotiated in online settings. News articles, public online discussions, and online fieldwork formed the data. This paper demonstrates how dominant drug discourses may be resisted by drug users, drawing on theories of health resistance and Kane Race’s concept of counter public health. Online environments may offer ways of engaging people who use drugs that acknowledge both pleasure and safety. The study’s limitations are noted

Liquid exfoliation of solvent-stabilized few-layer black phosphorus for applications beyond electronics

Few-layer black phosphorus (BP) is a new two-dimensional material which is of great interest for applications, mainly in electronics. However, its lack of environmental stability severely limits its synthesis and processing. Here we demonstrate that high-quality, few-layer BP nanosheets, with controllable size and observable photoluminescence, can be produced in large quantities by liquid phase exfoliation under ambient conditions in solvents such as N-cyclohexyl-2-pyrrolidone (CHP). Nanosheets are surprisingly stable in CHP, probably due to the solvation shell protecting the nanosheets from reacting with water or oxygen. Experiments, supported by simulations, show reactions to occur only at the nanosheet edge, with the rate and extent of the reaction dependent on the water/oxygen content. We demonstrate that liquid-exfoliated BP nanosheets are potentially useful in a range of applications from ultrafast saturable absorbers to gas sensors to fillers for composite reinforcement

Identification of DHX9 as a cell cycle regulated nucleolar recruitment factor for CIZ1

CIP1-interacting zinc finger protein 1 (CIZ1) is a nuclear matrix associated protein that facilitates a number of nuclear functions including initiation of DNA replication, epigenetic maintenance and associates with the inactive X-chromosome. Here, to gain more insight into the protein networks that underpin this diverse functionality, molecular panning and mass spectrometry are used to identify protein interaction partners of CIZ1, and CIZ1 replication domain (CIZ1-RD). STRING analysis of CIZ1 interaction partners identified 2 functional clusters: ribosomal subunits and nucleolar proteins including the DEAD box helicases, DHX9, DDX5 and DDX17. DHX9 shares common functions with CIZ1, including interaction with XIST long-non-coding RNA, epigenetic maintenance and regulation of DNA replication. Functional characterisation of the CIZ1-DHX9 complex showed that CIZ1-DHX9 interact in vitro and dynamically colocalise within the nucleolus from early to mid S-phase. CIZ1-DHX9 nucleolar colocalisation is dependent upon RNA polymerase I activity and is abolished by depletion of DHX9. In addition, depletion of DHX9 reduced cell cycle progression from G1 to S-phase in mouse fibroblasts. The data suggest that DHX9-CIZ1 are required for efficient cell cycle progression at the G1/S transition and that nucleolar recruitment is integral to their mechanism of action