Intervention for Cognitive Reserve Enhancement in Delaying the Onset of Alzheimer's Symptomatic Expression (INCREASE) Study: Results from a Randomized Controlled Study of Medication Therapy Management Targeting a Delay in Prodromal Dementia Symptom Progression.

BACKGROUND: Cognitive reserve has been hypothesized as a mechanism to explain differences in individual risk for symptomatic expression of Alzheimer's Disease (AD). Inappropriate medications may diminish cognitive reserve, precipitating the transition from preclinical AD (pAD) to a symptomatic state. To date, there is limited data on the potential impact of medication optimization as a potential tool for slowing the symptomatic expression of AD. OBJECTIVES: (1) To test the efficacy of a medication therapy management intervention designed to bolster cognitive reserve in community-dwelling older adults without dementia. (2) To evaluate the efficacy of intervention by baseline pAD status. DESIGN: A 1-year randomized controlled trial was conducted in community-dwelling older adults without dementia. Randomization was stratified by amyloid ß positron emission tomography levels. SETTING: Community-based, Lexington, Kentucky. PARTICIPANTS: Adults 65 years or older with no evidence of dementia and reporting at least one potentially inappropriate medication as listed in the Beers 2015 criteria were recruited. The study aimed to enroll 90 participants based on the a priori sample size calculation. INTERVENTION: Medication therapy management versus standard of care. MEASUREMENTS: Primary outcomes were: (1) one-year changes in the Medication Appropriateness Index; (2) one-year changes in Trail Making Test B under scopolamine challenge. RESULTS: The medication therapy management intervention resulted in significant improvement in Medication Appropriateness Index scores. Overall, there was no beneficial effect of the medication therapy management on Trail Making Test B scores, however stratified analysis demonstrated improvement in Trail Making Test B challenged scores associated with the medication therapy management for those with elevated amyloid ß positron emission tomography levels consistent with pAD. CONCLUSIONS: Medication therapy management can reduce inappropriate medication use in older adults at risk for AD. Our study indicated beneficial cognitive effects in those with preclinical Alzheimer's Disease. No statistically significant effects were evident in the study group as a whole, or in those without preclinical cerebral amyloidosis. Further work designed to improve the effectiveness of the medication therapy management approach and defining other preclinical pathologic states that may benefit from medication optimization are readily achievable goals for promoting improved cognitive health and potentially delaying the onset of symptomatic AD.

Entamoeba histolytica trophozoites induce an inflammatory cytokine response by cultured human cells through the paracrine action of cytolytically released interleukin-1 alpha.

Infection with the protozoan parasite Entamoeba histolytica results in a high mortality worldwide. To initiate infection, E. histolytica trophozoites in the bowel lumen penetrate the epithelium, and cause extensive lysis of host cells. The acute amebic lesions in animal models are characterized by infiltration with inflammatory cells, particularly neutrophils. The acute host response is likely important for determining whether the infection will spread systemically, but little is known regarding the signals which initiate an acute inflammatory response to E. histolytica. In the studies reported herein, we used an in vitro model system to define the proinflammatory signals produced by epithelial and other host cells in response to infection with E. histolytica trophozoites. Coculture of human epithelial and stromal cells and cell lines with trophozoites is shown to increase expression and secretion of an array of chemoattractant and proinflammatory cytokines, including IL-8, GRO alpha, GM-CSF, IL-1 alpha, and IL-6. Moreover, high-level secretion of those cytokines is regulated by the paracrine action of cytolytically released IL-1 alpha. A second mechanism for trophozoite-induced IL-8 production involves trophozoite-target cell contact via a galactose-inhibitable amebic adherence protein, and appears to be mediated through increased intracellular calcium levels. These studies define novel mechanisms through which acute inflammation can be initiated in the host in response to a cytolytic pathogen, such as E. histolytica.

Infection of human intestinal epithelial cells with invasive bacteria upregulates apical intercellular adhesion molecule-1 (ICAM)-1) expression and neutrophil adhesion.

The acute host response to gastrointestinal infection with invasive bacteria is characterized by an accumulation of neutrophils in the lamina propria, and neutrophil transmigration to the luminal side of the crypts. Intestinal epithelial cells play an important role in the recruitment of inflammatory cells to the site of infection through the secretion of chemokines. However, little is known regarding the expression, by epithelial cells, of molecules that are involved in interactions between the epithelium and neutrophils following bacterial invasion. We report herein that expression of ICAM-1 on human colon epithelial cell lines, and on human enterocytes in an in vivo model system, is upregulated following infection with invasive bacteria. Increased ICAM-1 expression in the early period (4-9 h) after infection appeared to result mainly from a direct interaction between invaded bacteria and host epithelial cells since it co-localized to cells invaded by bacteria, and the release of soluble factors by epithelial cells played only a minor role in mediating increased ICAM-1 expression. Furthermore, ICAM-1 was expressed on the apical side of polarized intestinal epithelial cells, and increased expression was accompanied by increased neutrophil adhesion to these cells. ICAM-1 expression by intestinal epithelial cells following infection with invasive bacteria may function to maintain neutrophils that have transmigrated through the epithelium in close contact with the intestinal epithelium, thereby reducing further invasion of the mucosa by invading pathogens.

Apoptosis of human intestinal epithelial cells after bacterial invasion.

Epithelial cells that line the human intestinal mucosa are the initial site of host invasion by bacterial pathogens. The studies herein define apoptosis as a new category of intestinal epithelial cell response to bacterial infection. Human colon epithelial cells are shown to undergo apoptosis following infection with invasive enteric pathogens, such as Salmonella or enteroinvasive Escherichia coli. In contrast to the rapid onset of apoptosis seen after bacterial infection of mouse monocyte-macrophage cell lines, the commitment of human intestinal epithelial cell lines to undergo apoptosis is delayed for at least 6 h after bacterial infection, requires bacterial entry and replication, and the ensuing phenotypic expression of apoptosis is delayed for 12-18 h after bacterial entry. TNF-alpha and nitric oxide, which are produced as components of the intestinal epithelial cell proinflammatory program in the early period after bacterial invasion, play an important role in the later induction and regulation of the epithelial cell apoptotic program. Apoptosis in response to bacterial infection may function to delete infected and damaged epithelial cells and restore epithelial cell growth regulation and epithelial integrity that are altered during the course of enteric infection. The delay in onset of epithelial cell apoptosis after bacterial infection may be important both to the host and the invading pathogen since it provides sufficient time for epithelial cells to generate signals important for the activation of mucosal inflammation and concurrently allows invading bacteria time to adapt to the intracellular environment before invading deeper mucosal layers.

A distinct array of proinflammatory cytokines is expressed in human colon epithelial cells in response to bacterial invasion.

Pathogenic bacteria that penetrate the intestinal epithelial barrier stimulate an inflammatory response in the adjacent intestinal mucosa. The present studies asked whether colon epithelial cells can provide signals that are important for the initiation and amplification of an acute mucosal inflammatory response. Infection of monolayers of human colon epithelial cell lines (T84, HT29, Caco-2) with invasive strains of bacteria (Salmonella dublin, Shigella dysenteriae, Yersinia enterocolitica, Listeria monocytogenes, enteroinvasive Escherichia coli) resulted in the coordinate expression and upregulation of a specific array of four proinflammatory cytokines, IL-8, monocyte chemotactic protein-1, GM-CSF, and TNF alpha, as assessed by mRNA levels and cytokine secretion. Expression of the same cytokines was upregulated after TNF alpha or IL-1 stimulation of these cells. In contrast, cytokine gene expression was not altered after infection of colon epithelial cells with noninvasive bacteria or the noninvasive protozoan parasite, G. lamblia. Notably, none of the cell lines expressed mRNA for IL-2, IL-4, IL-5, IL-6, IL-12p40, IFN-gamma, or significant levels of IL-1 or IL-10 in response to the identical stimuli. The coordinate expression of IL-8, MCP-1, GM-CSF and TNF alpha appears to be a general property of human colon epithelial cells since an identical array of cytokines, as well as IL-6, also was expressed by freshly isolated human colon epithelial cells. Since the cytokines expressed in response to bacterial invasion or other proinflammatory agonists have a well documented role in chemotaxis and activation of inflammatory cells, colon epithelial cells appear to be programmed to provide a set of signals for the activation of the mucosal inflammatory response in the earliest phases after microbial invasion.

Role of intestinal epithelial cells in the host secretory response to infection by invasive bacteria. Bacterial entry induces epithelial prostaglandin h synthase-2 expression and prostaglandin E2 and F2alpha production.

Increased intestinal fluid secretion is a protective host response after enteric infection with invasive bacteria that is initiated within hours after infection, and is mediated by prostaglandin H synthase (PGHS) products in animal models of infection. Intestinal epithelial cells are the first host cells to become infected with invasive bacteria, which enter and pass through these cells to initiate mucosal, and ultimately systemic, infection. The present studies characterized the role of intestinal epithelial cells in the host secretory response after infection with invasive bacteria. Infection of cultured human intestinal epithelial cell lines with invasive bacteria, but not noninvasive bacteria, is shown to induce the expression of one of the rate-limiting enzymes for prostaglandin formation, PGHS-2, and the production of PGE2 and PGF2alpha. Furthermore, increased PGHS-2 expression was observed in intestinal epithelial cells in vivo after infection with invasive bacteria, using a human intestinal xenograft model in SCID mice. In support of the physiologic importance of epithelial PGHS-2 expression, supernatants from bacteria-infected intestinal epithelial cells were shown to increase chloride secretion in an in vitro model using polarized epithelial cells, and this activity was accounted for by PGE2. These studies define a novel autocrine/paracrine function of mediators produced by intestinal epithelial cells in the rapid induction of increased fluid secretion in response to intestinal infection with invasive bacteria.

Secretion of proinflammatory cytokines by epithelial cells in response to Chlamydia infection suggests a central role for epithelial cells in chlamydial pathogenesis.

Chlamydia species infect epithelial cells at mucosal surfaces, and are major causes of sexually transmitted diseases. Infection is characterized by inflammation which is exacerbated upon reinfection, ultimately leading to tissue damage and scarring. Although central for the development of disease manifestations, little is known about the mechanisms that initiate and sustain the inflammatory response to Chlamydia. Infection of cervical and colonic epithelial cells with Chlamydia trachomatis and Chlamydia psittaci is shown in the present studies to upregulate mRNA expression and secretion of the proinflammatory cytokines IL-8, GRO alpha, GM-CSF, and IL-6. In contrast to the rapid, but transient, cytokine induction following infection with other invasive bacteria, the epithelial cytokine response to Chlamydia was delayed until 20-24 h after infection, persisted throughout the chlamydial growth cycle (2-4 d), and required bacterial protein synthesis. Moreover, epithelial cell lines and primary endocervical epithelial cells released IL-1alpha after Chlamydia infection, and increased secretion of the proinflammatory cytokines could be inhibited by anti-IL-1alpha. This suggests that IL-1alpha, released following lysis of infected epithelial cells, may amplify the inflammatory response by stimulating additional cytokine production by noninfected neighboring cells. These findings suggest a novel pathophysiologic concept wherein the acute host response to Chlamydia at mucosal surfaces is primarily initiated and sustained by epithelial cells, the first and major targets of chlamydial infection.

Therapy for Clostridium difficile infection - any news beyond Metronidazole and Vancomycin?

INTRODUCTION: Infections with Clostridium difficile (CDI) represent a major burden for the health care system. Treatment is generally by antibiotic therapy with metronidazole and vancomycin, but efficacy remains suboptimal. Areas covered: This review discusses established and emerging treatment options for CDI, and current therapeutic guidelines, taking into account disease severity and risk of relapse. Expert commentary: New therapeutic approaches, including antibodies and new classes of antibiotics, and new measures for preventing infection with vaccines are under development in phase II/III clinical trials. We performed a systematic literature review using the search terms 'Clostridium difficile' and 'treatment'.

Analysis of host responses to microbial infection using gene expression profiling.

Gene expression profiling offers new opportunities for understanding host-cell responses to microbial pathogens and their products. Current strategies involve either first identifying mRNAs that differ in their expression status under different experimental conditions and later defining the identity of the respective genes (for example, differential display or serial analysis of gene expression), or alternatively assessing changes in the expression of already defined genes (for example, cDNA or oligonucleotide microarrays). Early studies indicate the power of gene expression profiling for providing new insights into groups of genes whose expression is altered during the course of host-microbe interactions, and for the discovery of cellular genes that were not previously recognized to be regulated by infection.

Nitroimidazole carboxamides as antiparasitic agents targeting Giardia lamblia, Entamoeba histolytica and Trichomonas vaginalis.

Diarrhoeal diseases caused by the intestinal parasites Giardia lamblia and Entamoeba histolytica constitute a major global health burden. Nitroimidazoles are first-line drugs for the treatment of giardiasis and amebiasis, with metronidazole 1 being the most commonly used drug worldwide. However, treatment failures in giardiasis occur in up to 20% of cases and development of resistance to metronidazole is of concern. We have re-examined 'old' nitroimidazoles as a foundation for the systematic development of next-generation derivatives. Using this approach, derivatisation of the nitroimidazole carboxamide scaffold provided improved antiparasitic agents. Thirty-three novel nitroimidazole carboxamides were synthesised and evaluated for activity against G. lamblia and E. histolytica. Several of the new compounds exhibited potent activity against G. lamblia strains, including metronidazole-resistant strains of G. lamblia (EC50 = 0.1-2.5 µM cf. metronidazole EC50 = 6.1-18 µM). Other compounds showed improved activity against E. histolytica (EC50 = 1.7-5.1 µM cf. metronidazole EC50 = 5.0 µM), potent activity against Trichomonas vaginalis (EC50 = 0.6-1.4 µM cf. metronidazole EC50 = 0.8 µM) and moderate activity against the intestinal bacterial pathogen Clostridium difficile (0.5-2 µg/mL, cf. metronidazole = 0.5 µg/mL). The new compounds had low toxicity against mammalian kidney and liver cells (CC50 > 100 µM), and selected antiparasitic hits were assessed for human plasma protein binding and metabolic stability in liver microsomes to demonstrate their therapeutic potential.

Intestinal epithelial cells as watchdogs for the natural immune system.

Intestinal epithelial cells secrete a spectrum of chemoattractant and proinflammatory cytokines after invasion by bacteria. We suggest the novel concept that epithelial cells not only act as a mechanical barrier to invasive bacteria, but that they also signal the presence of invasive pathogens to the mucosal immune and inflammatory cells.

Perturbations of multiple hemopoietic lineages in retrovirus-induced murine malignant histiocytosis.

A fatal systemic proliferation of malignant histiocytes resembling human malignant histiocytosis was induced in susceptible mice following infection with the murine retrovirus malignant histiocytosis sarcoma virus (MHSV). It is shown that MHSV additionally caused profound alterations of erythropoiesis, granulocytopoiesis and thrombocytopoiesis, and in the hemopoietic stem cell compartment. In the erythroid lineage, MHSV induced a normocytic peripheral anemia, which was paralleled by an unphysiologic, multifocal clonal expansion of erythroid blasts in the spleen. These cells were not transformed and appeared to have a maturation defect since blood reticulocytes did not increase above control values. Moreover, MHSV exerted cytopathic effects on neutrophilic granulocytes and megakaryocytes, since their numbers transiently decreased in the spleen, and agranulocytosis and thrombocytopenia was observed in the blood. Nonetheless, regeneration was found in both lineages at later stages of the infection, which was accompanied by a terminal granulocytosis. The number of lineage-committed and multipotential colony-forming cells in the CFU-S assay increased transiently, but decreased to very low levels in the final stages of the disease. Thus, the studies demonstrate that the same etiologic agent, MHSV, had different effects on hemopoietic cells, which included malignant transformation, hyperproliferative and cytopathic effects.

Cytokines in host defense against Salmonella.

Cytokines are key communication molecules between host cells in the defense against the enteric pathogen, Salmonella. Infection with Salmonella induces expression of multiple chemokines and proinflammatory cytokines in cultured intestinal epithelial cells and macrophages. In animal models, protective roles have been shown for IL-1alpha, TNFalpha, IFN-gamma, IL-12, IL-18 and IL-15, whereas IL-4 and IL-10 inhibit host defenses against Salmonella.

Pathogenesis of Cryptosporidium parvum infection.

Cryptosporidium parvum can be regarded as a minimally invasive mucosal pathogen, since it invades surface epithelial cells that line the intestinal tract but does not invade deeper layers of the intestinal mucosa. Nonetheless, infection can be associated with diarrhea and marked mucosal inflammation. This article briefly reviews in vitro and in vivo models useful for studying the pathogenesis of C. parvum infection and explores the role of innate and acquired immune responses in host defense against this protozoan parasite.

Synergistic interactions allow colony formation in vitro by murine haemopoietic stem cells.

A clonogenic assay for cells that give rise to macroscopic colonies in agar or methyl cellulose cultures using untreated, normal murine bone marrow as a source of stem cells is described. We have characterized the clonogenic cell, which has been designated CFU-A, by comparing its properties with those of multipotential stem cells (assayed as CFU-S) and lineage-restricted progenitor cells (assayed as GM-CFC). The investigations have included assessment of proliferative status and response to CFU-S proliferation regulators, response to 5-fluorouracil, buoyant cell density, radial distribution in the femur and response to ionizing radiation. We conclude that the CFU-A has properties in common with CFU-S that differ from those of GM-CFC. The data are consistent with the CFU-A assay detecting part of the multipotential stem cell population also detected by spleen colony formation.

[Sound surgical procedures for the aged]. / Altersgerechtes Vorgehen in der Chirurgie.

Surgery of the aged implies consideration of a variety of pathophysiological conditions, which do differ from those seen in patients of the younger generation. Assessment, preparation, indication, choice of surgical procedure, nursing and aftercare have to comply accordingly. The ruling points of view are discussed methodically and illustrated by examples.

Protection against colitis by CD100-dependent modulation of intraepithelial γδ T lymphocyte function.

Intraepithelial γδ T lymphocytes (γδ IEL) have important roles in repair of tissue damage at epithelial sites, such as skin and intestine. Molecules that orchestrate these γδ T-cell functions are not well defined. Recently, interaction of the semaphorin CD100 on skin γδ T cells with plexin B2 on keratinocytes was shown to be important for effective γδ T-cell function in the epidermis, which raised the possibility that CD100 may exert similar functions in the intestinal tract. In this study, we find that CD100 is expressed on all IEL, and plexin B2 is present on all epithelial cells of the mouse colon. Using the dextran sulfate sodium (DSS) mouse model of colitis, disease severity is significantly exacerbated in CD100-deficient (CD100(-/-)) mice, with increased colon ulceration and mucosal infiltration with inflammatory cells. The severe colitis in CD100(-/-) mice is attributable to the failure of the colon epithelium to mount a proliferative response to damage. Unlike wild-type γδ IEL, γδ IEL from CD100(-/-) mice fail to produce keratinocyte growth factor-1 (KGF-1) in response to DSS treatment. Administration of recombinant KGF-1 to CD100(-/-) animals ameliorates disease and reverses colitis susceptibility. These results demonstrate that CD100-mediated signals are critical for effective activation of γδ IEL to produce growth factors, including KGF-1, that are required for healing of the colon epithelium during colitis.

Validated gene expression biomarker analysis for biopsy-based clinical trials in ulcerative colitis.

BACKGROUND: Accurate and reproducible measurement of expression of pro-inflammatory cytokines in colonic biopsies from patients with ulcerative colitis (UC) is essential for proof-of-concept and mechanism-of-action studies. Few studies have rigorously established the number of biopsies required for accurate and reproducible biomarker measurements. AIM: To validate methods for measuring changes in gene expression in colonic biopsy samples. METHODS: Twelve colonic biopsies were obtained from each of six healthy controls, six patients with inactive UC and seven patients with active UC. Mayo endoscopic scores were used as a clinical reference standard. Quantitative PCR was used to assess mRNA expression of eight known inflammatory genes. The power to detect a reduction in gene expression in active vs. inactive UC was calculated using a linear mixed effect model. RESULTS: mRNA analysis of colonic biopsies is a sensitive and feasible approach for measuring inflammatory gene expression in colonic biopsies. Inflammatory biomarkers correlate with Mayo endoscopic subscores for each colonic region. For most genes, three rectal biopsies from two to four patients are required to detect changes in gene expression corresponding to active vs. inactive UC to achieve a power of 80% with an alpha of 0.05. CONCLUSION: Our data suggest that systematic measurement of inflammatory biomarkers at the mRNA level can be a valuable tool for hypothesis testing, and assessment of clinical activity and response to therapy in ulcerative colitis.

Immunization of mice with Lactobacillus casei expressing a beta-intimin fragment reduces intestinal colonization by Citrobacter rodentium.

Enteropathogenic Escherichia coli (EPEC) is a common cause of diarrhea in children from developing countries. Intimate adhesion of the bacteria to intestinal cells occurs via binding of the adhesin intimin to the TIR receptor exposed on cell surfaces. Here, Lactobacillus casei expressing a fragment of ß-intimin (L. casei-Int(cv)) was tested as mucosal vaccines in mice against intestinal colonization with the murine pathogen Citrobacter rodentium. Oral or sublingual immunization of C57BL/6 mice with L. casei-Int(cv) induced anti-Int(cv) IgA in feces but no IgG in sera. Conversely, anti-Int(cv) IgG was induced in the sera of mice after sublingual immunization with purified Int(cv). All vaccines were able to decrease C. rodentium recovery from feces. However, this reduction was more evident and sustained over time in mice immunized with L. casei-Int(cv) by the sublingual route. These mice also displayed an increase in interleukin 6 (IL-6) and gamma interferon (IFN-γ) secretion by spleen cells 10 days after infection. Additionally, oral or sublingual immunization of C3H/HePas mice, which are highly susceptible to C. rodentium infection, with L. casei-Int(cv) induced anti-Int(cv) antibodies and significantly increased survival after challenge. Immunohistological analysis of colon sections revealed that C. rodentium was located in deep fractions of the tissue from C3H/HePas mice immunized with L. casei whereas superficial staining was observed in colon sections from mice immunized with L. casei-Int(cv.) The results indicate that vaccines composed of L. casei expressing intimin may represent a promising approach and that the C3H/HePas infection model with C. rodentium can be used to evaluate potential vaccines against EPEC.