Interleukin-1-induced leukocyte extravasation across rat mesenteric microvessels is mediated by platelet-activating factor

Although our understanding of the molecular interactions that mediate the adhesion of leukocytes to venular endothelial cells has greatly expanded, very little is known about the mechanisms that mediate the passage of leukocytes across the vessel wall in vivo. The aim of the present study was to investigate the role of endogenously formed platelet-activating factor (PAF) in the process of leukocyte extravasation induced by interleukin-1 (IL-1). To determine at which stage of emigration PAF was involved, we studied the behavior of leukocytes within rat mesenteric microvessels by intravital microscopy. Rats were injected intraperitoneally with saline, recombinant rat IL-1 beta (IL-1 beta), or the peptide N-formyl-methionyl-leucyl- phenylalanine (FMLP) 4 hours before the exteriorization of the mesenteric tissue. In animals treated with IL-1 beta there was a significant increase in the number of rolling and adherent leukocytes within venules (20- to 40-micron diameter) and in the number of extravasated leukocytes in the tissue. Pretreatment of rats with the PAF receptor antagonist UK-74,505 had no effect on the leukocyte responses of rolling and adhesion, but significantly inhibited the migration of the leukocytes across the vessel wall induced by IL-1 beta (76% inhibition). A structurally unrelated PAF antagonist, WEB-2170, produced the same effect (64% inhibition). However, in contrast, UK- 74,505 had no effect on the leukocyte extravasation induced by FMLP, indicating selectivity for the response elicited by certain mediators. These results provide the first line of direct evidence for the involvement of endogenously formed PAF in the process of leukocyte extravasation induced by IL-1 in vivo.     

The Role of Serotonin (5-HT) in Behavioral Control: Findings from Animal Research and Clinical Implications

The neurotransmitters serotonin and dopamine both have a critical role in the underlying neurobiology of different behaviors. With focus on the interplay between dopamine and serotonin, it has been proposed that dopamine biases behavior towards habitual responding, and with serotonin offsetting this phenomenon and directing the balance toward more flexible, goal-directed responding. The present focus paper stands in close relationship to the publication by Worbe et al. (2015), which deals with the effects of acute tryptophan depletion, a neurodietary physiological method to decrease central nervous serotonin synthesis in humans for a short period of time, on the balance between hypothetical goal-directed and habitual systems. In that research, acute tryptophan depletion challenge administration and a following short-term reduction in central nervous serotonin synthesis were associated with a shift of behavioral performance towards habitual responding, providing further evidence that central nervous serotonin function modulates the balance between goal-directed and stimulus-response habitual systems of behavioral control. In the present focus paper, we discuss the findings by Worbe and colleagues in light of animal experiments as well as clinical implications and discuss potential future avenues for related research.     

Expression of CD27 and its ligand, CD70, on chronic lymphocytic leukemia B cells

Crosslinking the CD27 antigen on T cells provides a costimulatory signal that, in concert with T-cell receptor crosslinking, can induce T- cell proliferation and cellular immune activation. We find that chronic lymphocytic leukemia (CLL) B cells from most patients coexpress both membrane-bound and soluble CD27, along with its newly identified ligand, CD70. The expression of soluble CD27 may preclude leukemic B cells from stimulating T cells via CD70, thereby potentially impairing their ability to function as effective antigen-presenting cells. We find that leukemic B-cell expression of soluble and membrane-bound CD27 can be downmodulated through a CD40-dependent signal. This signal also induces enhanced expression of CD70 on both normal and leukemic B cells. We find that tumor necrosis factor (TNF)-alpha, or the Th1 cytokine interferon (IFN)-gamma, also can induce downmodulation of CD27, whereas Th2-associated cytokines interleukin-4 (IL-4) or IL-10 can enhance leukemic B-cell expression of this accessory molecule. The modulation of CD27 induced by these conditions is accompanied by reciprocal changes in the expression levels of CD70, suggesting that these accessory molecules may be engaged in reciprocal receptor-ligand downmodulation. Consistent with this, we observe that co-culture of CLL B cells with transfected murine plasmacytoma cells that express human CD70 affects downmodulation of CD27 and enhanced expression of CD70 on leukemic B cells, but does not affect expression of CD27 mRNA. However, we find that CD40-crosslinking, in addition to reducing the level of CD27 protein, also reduces leukemic B-cell expression of CD27 mRNA. This argues that the changes in the expression levels of CD27 following CD40-signaling are not simply due to induced increases in the expression levels of CD70. Finally, we demonstrate that reciprocal changes in expression of CD27 and CD70 may contribute to the enhanced antigen-presenting capacity of CLL B cells after CD40-dependent leukemic B-cell activation. These findings expand the understanding of the regulation of costimulatory molecules important in antigen presentation and also have implications for the immunobiology of and therapy for CLL.     

Bone marrow transplantation for children with severe aplastic anemia: use of donors other than HLA-identical siblings

Eighty-five percent of untransfused and 70% of transfused patients with severe aplastic anemia (SAA) are cured with bone marrow transplants from histocompatible sibling donors. Use of partially matched family donors or unrelated donors has been relatively unsuccessful because of high incidences of graft rejection and graft-versus-host disease (GVHD). Thirteen children with SAA received marrow grafts from alternative donors (sibling 4, parent 5, unrelated 4). The first three patients were pretreated with cyclophosphamide (CYCLO) +/- irradiation and received methotrexate for GVHD prophylaxis. Subsequent children were pretreated with CYCLO + high-dose cytosine arabinoside + methylprednisolone + total body irradiation, had monoclonal antibody T- cell depletion of the donor marrow, and received cyclosporine for GVHD prophylaxis. Three heavily transfused patients with haploidentical- related donors failed to engraft and died. All 10 patients with more closely matched donors engrafted. Acute GVHD was grade II in only one patient (non-T-depleted); this patient is the only one with severe chronic GVHD. Three engrafted patients died (Pneumocystis pneumonia, systemic parainfluenza, venocclusive disease). Seven children are alive 33+ to 2,692+ days. Donors for the survivors were siblings 3, parent 1, unrelated 3. These data suggest that bone marrow transplantation from closely matched donors other than histocompatible siblings can be effective therapy for SAA if an intensive conditioning regimen is used. These results must be confirmed with larger numbers and longer follow- up.     

Attitudes to weight and weight management in the early teenage years: a qualitative study of parental perceptions and views

Background

As most young teenagers grow up in families, parents might be well situated to facilitate and support their weight management and thereby prevent or manage obesity prior to adulthood.

Aim

This paper explores parents'' perceptions of, and views about, their teenage children''s weight and the factors that influence parents'' weight management strategies.

Design, setting and participants

We conducted two qualitative studies in Scotland, UK, involving in‐depth interviews with the parents of overweight/obese and ‘normal’ weight 13–15 year olds (n = 69).

Findings

Parents'' concerns about their own weight provided useful context for understanding their attitudes or actions with regards to their teenage child. Some parents described their teenager''s weight as being of concern to them, although puberty often introduced confusion about a child''s weight status. Genetic explanations were very often put forward as a way of making sense of teenage weight or body size. Frustration about advising teenagers about weight management was expressed, and some parents worried about giving their growing child a ‘problem’ if they directly raised concerns about weight with them.

Discussion

Parents'' views about their own weight as well as social and moral norms about labelling a teenager as overweight or as needing help with their weight could usefully inform patient‐centred service development. Parent/teenage partnerships and supporting parents to create a healthy home in which teenagers can make healthier choices are suggestions for intervention development.

Conclusion

The study highlights the importance of taking parents'' perceptions into account when developing family‐based interventions to address teenage overweight and obesity.     

A unique water optional health care personnel handwash provides antimicrobial persistence and residual effects while decreasing the need for additional products

BACKGROUND: The Centers for Disease Control and Prevention (CDC) has published guidelines for hand hygiene practices, recommending a handwash regimen that alternates between waterless alcohol products and antimicrobial or nonantimicrobial soap and water. The advent of an alcohol-based product that can be used with or without water (ie, water optional) to decontaminate the hands while providing immediacy of kill and antimicrobial persistence could reduce the confusion associated with handwash guidelines. Such a product has been developed, is alcohol-based (61%), and zinc pyrithione (ZPT) preserved (61% alcohol-ZPT) and has proven to be fully compliant with the Food and Drug Administration (FDA) and CDC guidelines. METHODS: FDA-required testing of the 61% alcohol-ZPT product for the health care personnel handwash indication was performed as outlined in the Tentative Final Monograph (TFM) for Health-Care Antiseptic Drug Products, employing waterless and water-aided product applications. It was next assessed for antimicrobial persistence and residual effects by comparing it, in separate waterless and water-aided applications, with commonly available handwashes containing various antimicrobials in a 5-day study employing 49 subjects, in which samples were collected immediately and at 4 hours and 8 hours postapplication. The skin conditioning properties of this formulation were investigated via appropriate methods. RESULTS: The 61% alcohol-ZPT product easily produced >3.0 log 10 reduction in the indicator strain ( Serratia marcescens ) following the first wash, exceeding the 2.0 log 10 FDA requirement. This level of performance was maintained through the tenth wash, surpassing the 3.0 log 10 FDA requirement for the handwash indication. For the assessment of persistence and residual effect in the waterless mode, the water-optional, 61% alcohol-ZPT product consistently produced log 10 reductions of nearly 3.5 or greater at every point over the entire study period. In the water-aided configuration, similar results were obtained as log 10 reductions of 2.5 were observed. The formulation is nonirritating, actually contributing to hand skin condition. CONCLUSIONS: The 61% alcohol-ZPT product exceeds all FDA criteria for the health care personnel handwash indication and is a significant advancement in the concept of skin antisepsis. It represents a single product suitable for use in all hand hygiene settings, demonstrating improved antimicrobial persistence and residual effects. The 61% alcohol-ZPT formulation contributes positively to overall hand conditioning, and a previously reported study has documented it to be virucidal for several DNA and RNA viruses.