Improving Breast and Cervical Cancer Screening Compliance Through Direct Physician Contact in a Military Treatment Facility: A Non-randomized Pilot Study

INTRODUCTION

Screening for breast cancer (BC) and cervical cancer (CC) decreases morbidity and mortality. Most interventions to improve screening rely on automated modalities or nonphysician patient contact. There is limited data on direct patient contact by a physician to encourage BC and CC screening. This non-randomized pilot study sought to evaluate the potential of direct physician contact to improve BC and CC screening rates.

MATERIALS AND METHODS

A Family Medicine physician telephoned patients on his panel who were due or overdue for BC and CC screening. If the patient did not answer her phone, a voicemail was left; if unable to leave a voicemail, a letter was mailed. The completion rate of recommended screening tests was measured 3 months after contact and compared to a retrospectively identified control population. The change in compliance of the patient panel over 3 months was also calculated.

RESULTS

Direct physician conversation by telephone yielded higher completion rates for BC and CC screening versus control patients, but only the CC completion rate increase was statistically significant. Direct conversation BC screening completion rate: 41.2% versus 22.7% (P = .22, n = 48). Direct conversation CC screening completion rate: 45% versus 13.9% (P = .01, n = 44). The intervention patient panel compliance with screening recommendations increased 20.5% for BC and 10.5% for CC.

CONCLUSION

Direct physician contact may be beneficial to increase compliance for more invasive screening tests.

Temporal evolution of the microbiome, immune system and epigenome with disease progression in ALS mice

Amyotrophic lateral sclerosis (ALS) is a terminal neurodegenerative disease. Genetic predisposition, epigenetic changes, aging and accumulated life-long environmental exposures are known ALS risk factors. The complex and dynamic interplay between these pathological influences plays a role in disease onset and progression. Recently, the gut microbiome has also been implicated in ALS development. In addition, immune cell populations are differentially expanded and activated in ALS compared to healthy individuals. However, the temporal evolution of both the intestinal flora and the immune system relative to symptom onset in ALS is presently not fully understood. To better elucidate the timeline of the various potential pathological factors, we performed a longitudinal study to simultaneously assess the gut microbiome, immunophenotype and changes in ileum and brain epigenetic marks relative to motor behavior and muscle atrophy in the mutant superoxide dismutase 1 (SOD1G93A) familial ALS mouse model. We identified alterations in the gut microbial environment early in the life of SOD1G93A animals followed by motor dysfunction and muscle atrophy, and immune cell expansion and activation, particularly in the spinal cord. Global brain cytosine hydroxymethylation was also altered in SOD1G93A animals at disease end-stage compared to control mice. Correlation analysis confirmed interrelationships with the microbiome and immune system. This study serves as a starting point to more deeply comprehend the influence of gut microorganisms and the immune system on ALS onset and progression. Greater insight may help pinpoint novel biomarkers and therapeutic interventions to improve diagnosis and treatment for ALS patients.This article has an associated First Person interview with the joint first authors of the paper.

Infectious particle identity determines dissemination and disease outcome for the inhaled human fungal pathogen Cryptococcus

The majority of invasive human fungal pathogens gain access to their human hosts via the inhalation of spores from the environment into the lung, but relatively little is known about this infectious process. Among human fungal pathogens the most frequent cause of inhaled fatal fungal disease is Cryptococcus, which can disseminate from the lungs to other tissues, including the brain, where it causes meningoencephalitis. To determine the mechanisms by which distinct infectious particles of Cryptococcus cause disseminated disease, we evaluated two developmental cell types (spores and yeast) in mouse models of infection. We discovered that while both yeast and spores from several strains cause fatal disease, there was a consistently higher fungal burden in the brains of spore-infected mice. To determine the basis for this difference, we compared the pathogenesis of avirulent yeast strains with their spore progeny derived from sexual crosses. Strikingly, we discovered that spores produced by avirulent yeast caused uniformly fatal disease in the murine inhalation model of infection. We determined that this difference in outcome is associated with the preferential dissemination of spores to the lymph system. Specifically, mice infected with spores harbored Cryptococcus in their lung draining lymph nodes as early as one day after infection, whereas mice infected with yeast did not. Furthermore, phagocyte depletion experiments revealed this dissemination to the lymph nodes to be dependent on CD11c+ phagocytes, indicating a critical role for host immune cells in preferential spore trafficking. Taken together, these data support a model in which spores capitalize on phagocytosis by immune cells to escape the lung and gain access to other tissues, such as the central nervous system, to cause fatal disease. These previously unrealized insights into early interactions between pathogenic fungal spores and lung phagocytes provide new opportunities for understanding cryptococcosis and other spore-mediated fungal diseases.

Helper T-cell responses and pulmonary fungal infections

The mucosal surface of the respiratory tract encounters microbes, such as fungal particles, with every inhaled breath. When pathogenic fungi breach the physical barrier and innate immune system within the lung to establish an infection, adaptive immunity is engaged, often in the form of helper CD4 T-cell responses. Type 1 responses, characterized by interferon-γ production from CD4 cells, promote clearance of Histoplasma capsulatum and Cryptococcus neoformans infection. Likewise, interleukin-17A (IL-17A) production from Th17 cells promotes immunity to Blastomyces dermatitidis and Coccidioides species infection by recruiting neutrophils. In contrast the development of T helper type 2 responses, characterized by IL-5 production from T cells and eosinophil influx into the lungs, drives allergic bronchopulmonary aspergillosis and poor outcomes during C. neoformans infection. Experimental vaccines against several endemic mycoses, including Histoplasma capsulatum, Coccidioides, Cryptococcus and Blastomyces dermatitidis, induce protective T-cell responses and foreshadow the development of vaccines against pulmonary fungal infections for use in humans. Additionally, recent work using antifungal T cells as immunotherapy to protect immune-compromised patients from opportunist fungal infections also shows great promise. This review covers the role of T-cell responses in driving protection and pathology in response to pulmonary fungal infections, and highlights promising therapeutic applications of antifungal T cells.

Croup: Diagnosis and Management

Croup is a common respiratory illness affecting 3% of children six months to three years of age. It accounts for 7% of hospitalizations annually for fever and/or acute respiratory illness in children younger than five years. Croup is a manifestation of upper airway obstruction resulting from swelling of the larynx, trachea, and bronchi, leading to inspiratory stridor and a barking cough. Many patients experience low-grade fevers, but fever is not necessary for diagnosis. Less commonly, stridor can be associated with acute epiglottitis, bacterial tracheitis, and foreign body airway obstruction. Laboratory studies are seldom needed for diagnosis of croup. Viral cultures and rapid antigen testing have minimal impact on management and are not routinely recommended. Radiography and laryngoscopy should be reserved for patients in whom alternative diagnoses are suspected. Randomized controlled trials have demonstrated that a single dose of oral, intramuscular, or intravenous dexamethasone improves symptoms and reduces return visits and length of hospitalization in children with croup of any severity. In patients with moderate to severe croup, the addition of nebulized epinephrine improves symptoms and reduces length of hospitalization.

Lung Epithelial Cells Coordinate Innate Lymphocytes and Immunity against Pulmonary Fungal Infection

Lung epithelial cells (LECs) are strategically positioned in the airway mucosa to provide barrier defense. LECs also express pattern recognition receptors and a myriad of immune genes, but their role in immunity is often concealed by the activities of "professional" immune cells, particularly in the context of fungal infection. Here, we demonstrate that NF-κB signaling in LECs is essential for immunity against the pulmonary fungal pathogen Blastomyces dermatitidis. LECs orchestrate innate antifungal immunity by augmenting the numbers of interleukin-17A (IL-17A)- and granulocyte-macrophage colony-stimulating factor (GM-CSF)-producing innate lymphocytes, specifically "natural" Th17 (nTh17) cells. Innate lymphocyte-derived IL-17A and GM-CSF in turn enable phagocyte-driven fungal killing. LECs regulate the numbers of nTh17 cells via the production of chemokines such as CCL20, a process dependent on IL-1α-IL-1 receptor (IL-1R) signaling on LECs. Therefore, LECs orchestrate IL-17A- and GM-CSF-mediated immunity in an IL-1R-dependent manner and represent an essential component of innate immunity to pulmonary fungal pathogens.

Inhaled Cryptococcus neoformans elicits allergic airway inflammation independent of Nuclear Factor Kappa B signalling in lung epithelial cells

Pulmonary challenge with the ubiquitous fungus Cryptococcus neoformans results in allergic airway inflammation (AAI) characterized by robust recruitment of eosinophils and T cells producing type 2 cytokines to the lungs. Previous studies have demonstrated a critical role for Nuclear Factor Kappa B (NF-κB) activation within lung epithelial cells (LECs) in driving AAI in response to protein allergens, yet the role of LEC-intrinsic NF-κB in promoting AAI following exposure to C. neoformans is poorly understood. To investigate the role of LEC-intrinsic NF-κB in promoting AAI following C. neoformans challenge, we used IKK^∆LEC mice, which lack canonical NF-κB activation specifically within LECs. IKK^∆LEC and littermate control mice were intranasally challenged with 10⁶ CFU of C. neoformans strain 52D, and lung tissues were collected at 7, 14 and 21 days post infection to assess the development of AAI. Notably, the absence of epithelial NF-κB signalling did not affect the magnitude or kinetics of lung eosinophilia when compared with the response in wild-type control mice. The total numbers of lung T cells producing the type 2 cytokines interleukin-5 and interleukin-13 were also unchanged in IKK^∆LEC mice. Furthermore, IKK^∆LEC mice showed no defect in the recruitment of protective interferon-γ-producing CD4 T cells to the lungs, fungal clearance, or host survival compared with control mice. Immunofluorescence imaging surprisingly revealed no evidence of nuclear localization of NF-κB in LECs in response to C. neoformans challenge, indicating that NF-κB is not activated within these cells. Taken together, these data strongly suggest that NF-κB signalling within LECs does not promote AAI observed in response to C. neoformans.

Antifungal Tc17 cells are durable and stable, persisting as long-lasting vaccine memory without plasticity towards IFNγ cells

Our understanding of persistence and plasticity of IL-17A⁺ memory T cells is clouded by conflicting results in models analyzing T helper 17 cells. We studied memory IL-17A⁺ CD8⁺ T-cell (Tc17) homeostasis, persistence and plasticity during fungal vaccine immunity. We report that vaccine-induced memory Tc17 cells persist with high fidelity to the type 17 phenotype. Tc17 cells persisted durably for a year as functional IL-17A⁺ memory cells without converting to IFNγ⁺ (Tc1) cells, although they produced multiple type I cytokines in the absence of residual vaccine antigen. Memory Tc17 cells were canonical CD8⁺ T cells with phenotypic features distinct from Tc1 cells, and were Ror(γ)t^hi, TCF-1^hi, T-bet^lo and EOMES^lo. In investigating the bases of Tc17 persistence, we observed that memory Tc17 cells had much higher levels of basal homeostatic proliferation than did Tc1 cells. Conversely, memory Tc17 cells displayed lower levels of anti-apoptotic molecules Bcl-2 and Bcl-xL than Tc1 cells, yet were resistant to apoptosis. Tc1 cells required Bcl-2 for their survival, but Bcl-2 was dispensable for the maintenance of Tc17 cells. Tc17 and Tc1 cells displayed different requirements for HIF-1α during effector differentiation and sustenance and memory persistence. Thus, antifungal vaccination induces durable and stable memory Tc17 cells with distinct requirements for long-term persistence that distinguish them from memory Tc1 cells.

CD4⁺ T-cell deficient patients such as those with AIDS and idiopathic CD4⁺ T-cell lymphopenia are vulnerable to systemic fungal infections. We previously showed that CD8⁺ T cells can be exploited in CD4⁺ T cell deficient hosts for vaccine immunity against lethal fungal pneumonia in mice and that IL-17A production by these cells (Tc17) is essential. Existing dogma holds that IL-17A producing CD4⁺ T cells (Th17) are highly plastic, unstable, and convert into IFNγ producing cells, losing the capacity to produce IL-17A, which is the signature feature of Tc17 cells. Here, we show that vaccine-elicited antifungal Tc17 cells are maintained as stable and long-lasting memory cells that resist conversion into IFNγ cells (Tc1) and protect CD4⁺ T cell deficient hosts against lethal pulmonary fungal infection. Antifungal Tc17 cells displayed features that define classical memory cells. However, memory Tc17 exhibited different requirements than Tc1 cells in the factors that promote T cell survival, including anti-apoptotic molecules Bcl-2 and Bcl-xl, and HIF-1α, which aids survival of cells in lower oxygen conditions found during inflammation. Thus, our study reveals that fungal vaccination elicits a durable, stable population of Tc17 cells with distinct features of survival needed for preventing infection in immunocompromised hosts.

Role of interferon-γ and inflammatory monocytes in driving colonic inflammation during acute Clostridium difficile infection in mice

The inflammatory response to the colonic pathogen Clostridium difficile is characterized by the induction of inflammatory cytokines including Interleukin-23 (IL-23) and interferon-γ (IFN-γ) and the recruitment of myeloid cells including Ly6C^High monocytes. IL-23 knockout mice showed reduced expression of the monocyte chemokines Ccl4 and Ccl7, but not Ccl2, as well as reduced Ly6C^High Ly6G^Mid monocyte recruitment to the colon in response to C. difficile colitis. Clostridium difficile-infected CCR2^-/- (CCR2 KO) mice showed a significant defect in Ly6C^High Ly6G^Mid monocyte recruitment to the colon in response to C. difficile. Although there was no decrease in expression of the inflammatory cytokines Il1b, Il6 or Tnf or reduction in the severity of colonic histopathology associated with ablation of monocyte recruitment, Slpi and Inos expression was significantly reduced in the colons of these animals. Additionally, neutralization of IFN-γ through the administration of anti-IFN-γ monoclonal antibody resulted in a significant reduction in the expression of the IFN-γ-inducible chemokines Cxcl9 and Cxcl10, but not a reduction in the neutrophil chemokines Cxcl1, Cxcl2 and Ccl3 or the monocyte chemokine Ccl2. Consistently, monocyte and neutrophil recruitment were unchanged following anti-IFN-γ treatment. Additionally, Inos and Slpi expression were unchanged following anti-IFN-γ treatment, suggesting that Inos and Slpi regulation is independent of IFN-γ during C. difficile colitis. Taken together, these data strongly suggest that IL-23 and CCR2 signalling are required for monocyte recruitment during C. difficile colitis. Additionally, these studies also suggest that monocytes, but not IFN-γ, are necessary for full expression of Inos and Slpi in the colon.

Interleukin-23 (IL-23), independent of IL-17 and IL-22, drives neutrophil recruitment and innate inflammation during Clostridium difficile colitis in mice

Our objective was to determine the role of the inflammatory cytokine interleukin-23 (IL-23) in promoting neutrophil recruitment, inflammatory cytokine expression and intestinal histopathology in response to Clostridium difficile infection. Wild-type (WT) and p19(-/-) (IL-23KO) mice were pre-treated with cefoperazone in their drinking water for 5 days, and after a 2-day recovery period were challenged with spores from C. difficile strain VPI 10463. Interleukin-23 deficiency was associated with significant defects in both the recruitment of CD11b(High) Ly6G(H) (igh) neutrophils to the colon and the expression of neutrophil chemoattractants and stabilization factors including Cxcl1, Cxcl2, Ccl3 and Csf3 within the colonic mucosa as compared with WT animals. Furthermore, the expression of inflammatory cytokines including Il33, Tnf and Il6 was significantly reduced in IL-23-deficient animals. There was also a trend towards less severe colonic histopathology in the absence of IL-23. The induction of Il17a and Il22 was also significantly abrogated in IL-23KO mice. Inflammatory cytokine expression and neutrophilic inflammation were not reduced in IL-17a-deficient mice or in mice treated with anti-IL-22 depleting monoclonal antibody. However, induction of RegIIIg was significantly reduced in animals treated with anti-IL-22 antibody. Taken together, these data indicate that IL-23, but not IL-17a or IL-22, promotes neutrophil recruitment and inflammatory cytokine and chemokine expression in the colon in response to C. difficile infection.

The role of Gr-1(+) cells and tumour necrosis factor-α signalling during Clostridium difficile colitis in mice

The host response to Clostridium difficile infection in antibiotic-treated mice is characterized by robust recruitment of Gr-1(+) cells, increased expression of inflammatory cytokines including tumour necrosis factor-α (TNF-α), and the development of severe epithelial damage. To investigate the role of Gr-1(+) cells and TNF-α during C. difficile colitis, we treated infected mice with monoclonal antibodies against Gr-1 or TNF-α. Mice were challenged with vegetative cells of C. difficile strain VPI 10463 following treatment with the third-generation cephalosporin ceftriaxone. Ceftriaxone treatment alone was associated with significant changes in cytokine expression within the colonic mucosa but not overt inflammatory histopathological changes. In comparison, C. difficile infection following ceftriaxone treatment was associated with increased expression of inflammatory cytokines and chemokines including Cxcl1, Cxcl2, Il1b, Il17f and Tnfa, as well as robust recruitment of Ly6C(Mid)  Gr-1(High) neutrophils and Ly6C(High) Gr-1(Mid) monocytes and the development of severe colonic histopathology. Anti-Gr-1 antibody treatment resulted in effective depletion of both Ly6C(Mid) Gr-1(High) neutrophils and Ly6C(High) Gr-1(Mid) monocytes: however, we observed no protection from the development of severe pathology or reduction in expression of the pro-inflammatory cytokines Il1b, Il6, Il33 and Tnfa following anti-Gr-1 treatment. By contrast, anti-TNF-α treatment did not affect Gr-1(+) cell recruitment, but was associated with increased expression of Il6 and Il1b. Additionally, Ffar2, Ffar3, Tslp, Tff and Ang4 expression was significantly reduced in anti-TNF-α-treated animals, in association with marked intestinal histopathology. These studies raise the possibility that TNF-α may play a role in restraining inflammation and protecting the epithelium during C. difficile infection.

Interleukin-22 and CD160 play additive roles in the host mucosal response to Clostridium difficile infection in mice

Our previous work has shown the significant up-regulation of Il22 and increased phosphorylation of signal transducer and activator of transcription 3 (STAT3) as part of the mucosal inflammatory response to Clostridium difficile infection in mice. Others have shown that phosphorylation of STAT3 at mucosal surfaces includes interleukin-22 (IL-22) and CD160-mediated components. The current study sought to determine the potential role(s) of IL-22 and/or CD160 in the mucosal response to C. difficile infection. Clostridium difficile-infected mice treated with anti-IL-22, anti-CD160 or a combination of the two showed significantly reduced STAT3 phosphorylation in comparison to C. difficile-infected mice that had not received either antibody. In addition, C. difficile-infected mice treated with anti-IL-22/CD160 induced a smaller set of genes, and at significantly lower levels than the untreated C. difficile-infected mice. The affected genes included pro-inflammatory chemokines and cytokines, and anti-microbial peptides. Furthermore, histopathological and flow cytometric assessments both showed a significantly reduced influx of neutrophils in C. difficile-infected mice treated with anti-IL-22/CD160. These data demonstrate that IL-22 and CD160 are together responsible for a significant fraction of the colonic STAT3 phosphorylation in C. difficile infection. They also underscore the additive effects of IL-22 and CD160 in mediating both the pro-inflammatory and pro-survival aspects of the host mucosal response in this infection.

Role of GM-CSF in the inflammatory cytokine network that regulates neutrophil influx into the colonic mucosa during Clostridium difficile infection in mice

Clostridium difficile infection in antibiotic-treated mice results in acute colitis characterized by severe intestinal histopathology, robust neutrophil influx, and increased expression of numerous inflammatory cytokines, including GM-CSF. We utilized a neutralizing monoclonal antibody (mAb) against GM-CSF in a murine model to study the role of GM-CSF during acute C. difficile colitis. Cefoperazone-treated mice were challenged with C. difficile (strain 630) spores. Expression of GM-CSF was significantly increased in animals challenged with C. difficile. Treatment with an anti-GM-CSF mAb did not alter C. difficile colonization levels, weight loss, or expression of IL-22 and RegIIIγ. However, expression of the inflammatory cytokines TNFα and IL-1β, as well as iNOS, was significantly reduced following anti-GM-CSF treatment. Expression of the neutrophil chemokines CXCL1 and CXCL2, but not the chemokines CCL2, CCL4, CXCL9, and CXCL10, was significantly reduced by anti-GM-CSF treatment. Consistent with a decrease in neutrophil-attractant chemokine expression, there were fewer neutrophils in histology sections and a reduction in the expression of secretory leukocyte protease inhibitor (SLPI), a tissue anti-protease that protects against damage by secreted neutrophil elastase. These data indicate that GM-CSF plays a role in the inflammatory signaling network that drives neutrophil recruitment in response to C. difficile infection but does not appear to play a role in clearance of the infection.

Tryptophan catabolism restricts IFN-γ-expressing neutrophils and Clostridium difficile immunopathology

The interplay between Clostridium difficile and the host's metabolome is believed to influence the severity of infection. However, the mechanism for this phenomenon remains unclear. In this study, we model one of these metabolic pathways by focusing on tryptophan metabolism in the host. We found that inhibition of tryptophan catabolism in IDO1-knockout mice led to increased mucosal destruction, cecal hemorrhage, and increased production of IFN-γ in response to C. difficile infection, but no significant change in mucosal effector or regulatory T cell numbers or IL-10 mRNA expression. The increased immunopathology in infected IDO1-knockout mice was associated with a lower C. difficile burden and an increased percentage of IFN-γ-expressing neutrophils. We further demonstrated the ability of kynurenine to induce apoptosis in bone marrow-derived neutrophils, whereas the presence of tryptophan reversed this effect, providing a possible mechanism for the increased neutrophil accumulation in IDO1(-/-) mice. We conclude that C. difficile induces tryptophan catabolism in cecal lamina propria cells, which restricts C. difficile-associated immunopathology and the accumulation of IFN-γ-expressing neutrophils. This might represent a self-regulatory mechanism for neutrophils, via the IFN-γ-IDO1 pathway, to restrict their own accumulation during infection. These findings have important clinical implications because IDO inhibitors are used to treat cancer in clinical trials (in patients particularly susceptible to getting C. difficile infection), and treatment with IDO1 inhibitors may exacerbate the severity of C. difficile colitis.

Toxic Epidermal Necrolysis from suspected Mycoplasma pneumoniae infection

INTRODUCTION

Toxic Epidermal Necrolysis (TEN) is primarily associated with medication use. Presented is a patient with likely Mycoplasma pneumoniae infection and progression to TEN.

CASE

A 19-year-old male presented with 1-week history of pneumonia like symptoms and prescribed antibiotics for suspected community-acquired pneumonia. Onset of a new rash was noted and antibiotics were discontinued less than 24 hours after initiation. The diffuse, maculopapular, bullous rash with mucosal lesions ultimately reached skin involvement greater than 30%. Histological studies were consistent with TEN. Mycoplasma antibodies and cold agglutinins were positive.

DISCUSSION

Stevens-Johnson syndrome (SJS) and TEN are a spectrum of mucocutaneous disorders. The most common etiology of both is medications. Mycoplasma is the most common infectious cause of SJS, but has been poorly cited as a cause of TEN. Typical onset of rash from medications is greater than 14 days, whereas onset from infection is typically less than 14 days. The timing of rash onset in this presentation was congruent with infection rather than medication induced.

CONCLUSION

Mycoplasma is a well-documented etiology of SJS, but rarely documented as an etiology of TEN. This case suggests the potential of Mycoplasma infection causing more severe mucocutaneous disease in the spectrum of SJS and TEN.

The microbiome and regulation of mucosal immunity

The gastrointestinal tract is a mucosal surface constantly exposed to foreign antigens and microbes, and is protected by a vast array of immunologically active structures and cells. Epithelial cells directly participate in immunological surveillance and direction of host responses in the gut and can express numerous pattern recognition receptors, including Toll-like receptor 5 (TLR5), TLR1, TLR2, TLR3, TLR9, and nucleotide oligomerization domain 2, as well as produce chemotactic factors for both myeloid and lymphoid cells following inflammatory stimulation. Within the epithelium and in the underlying lamina propria resides a population of innate lymphoid cells that, following stimulation, can become activated and produce effector cytokines and exert both protective and pathogenic roles during inflammation. Lamina propria dendritic cells play a large role in determining whether the response to a particular antigen will be inflammatory or anti-inflammatory. It is becoming clear that the composition and metabolic activity of the intestinal microbiome, as a whole community, exerts a profound influence on mucosal immune regulation. The microbiome produces short-chain fatty acids, polysaccharide A, α-galactosylceramide and tryptophan metabolites, which can induce interleukin-22, Reg3γ, IgA and interleukin-17 responses. However, much of what is known about microbiome-host immune interactions has come from the study of single bacterial members of the gastrointestinal microbiome and their impact on intestinal mucosal immunity. Additionally, evidence continues to accumulate that alterations of the intestinal microbiome can impact not only gastrointestinal immunity but also immune regulation at distal mucosal sites.

Acute infection of mice with Clostridium difficile leads to eIF2α phosphorylation and pro-survival signalling as part of the mucosal inflammatory response

The current study sought to delineate the gene expression profile of the host response in the caecum and colon during acute infection with Clostridium difficile in a mouse model of infection, and to investigate the nature of the unfolded protein response in this process. The infected mice displayed a significant up-regulation in the expression of chemokines (Cxcl1, Cxcl2 and Ccl2), numerous pro-inflammatory cytokines (Ifng, Il1b, Il6, and Il17f), as well as Il22 and a number of anti-microbial peptides (Defa1, Defa28, Defb1, Slpi and Reg3g) at the site(s) of infection. This was accompanied by a significant influx of neutrophils, dendritic cells, cells of the monocyte/macrophage lineage and all major subsets of lymphocytes to these site(s). However, CD4 T cells of the untreated and C. difficile-infected mice expressed similar levels of CD69 and CD25. Neither tissue had up-regulated levels of Tbx21, Gata3 or Rorc. The caeca and colons of the infected mice showed a significant increase in eukaryotic initiation factor 2α (eIF2α) phosphorylation, but neither the splicing of Xbp1 nor the up-regulation of endoplasmic reticulum chaperones, casting doubt on the full-fledged induction of the unfolded protein response by C. difficile. They also displayed significantly higher phosphorylation of AKT and signal transducer and activator of transcription 3 (STAT3), an indication of pro-survival signalling. These data underscore the local, innate, pro-inflammatory nature of the response to C. difficile and highlight eIF2α phosphorylation and the interleukin-22-pSTAT3-RegIIIγ axis as two of the pathways that could be used to contain and counteract the damage inflicted on the intestinal epithelium.

Cost of eating: whole foods versus convenience foods in a low-income model

BACKGROUND AND OBJECTIVES

Financial limitations in low-income populations, those at highest risk for poor health outcomes, may preclude adherence to recommended dietary guidelines. We examine the financial burden of shopping for foods to meet national dietary recommendations in a supermarket compared to eating primarily in a fast-food restaurant.

METHODS

Using a single-parent, low-income model, we obtained whole food costs (healthy) from local supermarkets and from fast-food outlets (convenient). Using cost per calorie as a metric for comparison, we used estimated single-parent, low-income living expenses to determine the relative costs of meeting national dietary guidelines.

RESULTS

Average food costs for healthy and convenience diets accounted for 18% and 37% of income, respectively. Dairy products and vegetables accounted for the largest cost percentages of diet costs (36% and 28%, respectively). The cost per calorie of a convenience diet was 24% higher than the healthy diet. Both models resulted in net financial loss over the course of a year for a single-parent, low-income family.

CONCLUSIONS

Food costs represent a significant proportion of annual income. Diets based heavily on foods from convenient sources are less healthy and more expensive than a well-planned menu from budget foods available from large supermarket chains.

Surface chemistry of a high-copper dental amalgam

In amalgam, mercury is intended to take the form of stable intermetallic compounds. Any mercury leakage must therefore come from free mercury not involved in such compounds. Thus, a knowledge of the exact surface chemistry of dental amalgam is necessary if this phenomenon is to be understood. From XPS and EDS analyses, a model of the surface chemistry of amalgam is proposed which fully characterizes all the phases that are present. The data show the surface to have a composition different from that of the bulk, being comprised of a hydrocarbon deposit and adsorbed water covering the intermetallic phase gamma2 (Sn(6-8)Hg), tin (iv) oxide, and mercury in a free state. After amalgamation, the amount of mercury at the surface decreases with time and eventually attains a constant concentration, where it is all involved in the gamma2 phase, leaving no free mercury. A model is proposed for the surface of amalgam and the changes in this model with time.