Book Reviews: Spring 2020

Book Reviews, of:Dalsgaard (ed) – Thomas Pynchon in ContextChetwynd, Freer, Maragos (eds) – Thomas Pynchon, Sex, and GenderMogultay – The Ruins of Urban Modernity: Thomas Pynchon's Against the DayAlworth – Site Reading: Fiction, Art, Social FormMullins – Postmodernism in Pieces: Materializing the SocialHenry – New Media and the Transformation of Postmodern American Literature: From Cage to Connectionden Dulk – Existentialist Engagement in Wallace, Eggers, and Foer: A Philosophical Analysis of Contemporary American LiteratureAnderson – Postmodern Artistry in Medievalist Fiction: An International StudyHouser – Ecosickness in Contemporary U.S. Fiction: Environment and AffectPalleau-Papin (ed) – Under Fire; William T. Vollmann, The Rifles: A Critical Study [a note from the Book Reviews Editor: if you're interested in reviewing a book on any aspect of unconventional post-1945 US literature, please send an email proposing a review to [email protected]

On the Interaction of Clostridium perfringens Enterotoxin with Claudins

Clostridium perfringens causes one of the most common foodborne illnesses, which is largely mediated by the Clostridium perfringens enterotoxin (CPE). The toxin consists of two functional domains. The N-terminal region mediates the cytotoxic effect through pore formation in the plasma membrane of the mammalian host cell. The C-terminal region (cCPE) binds to the second extracellular loop of a subset of claudins. Claudin-3 and claudin-4 have been shown to be receptors for CPE with very high affinity. The toxin binds with weak affinity to claudin-1 and -2 but contribution of these weak binding claudins to CPE-mediated disease is questionable. cCPE is not cytotoxic, however, it is a potent modulator of tight junctions. This review describes recent progress in the molecular characterization of the cCPE-claudin interaction using mutagenesis, in vitro binding assays and permeation studies. The results promote the development of recombinant cCPE-proteins and CPE-based peptidomimetics to modulate tight junctions for improved drug delivery or to treat tumors overexpressing claudins

Expression, pharmacology and functional role of somatostatin receptor subtypes 1 and 2 in human macrophages

Somatostatin (SRIF)-14 is recognized as an important mediator between the nervous and the immune system, although the functional role of its receptors (sst1-sst5) is poorly understood in humans. In our study, we demonstrate that human macrophages differentiated from peripheral blood mononuclear cell-derived monocytes express both sst1 and sst2 mRNAs. Both sst1 and sst2 are mostly localized at the cell surface and display active binding sites. In particular, sst1/sst2 activation results in a weak internalization of sst1 while the sst2 internalization appears more efficient. At the functional level, the activation of SRIF receptors by the multiligand analogues SOM230 and KE108, but not by SRIF-14 or cortistatin-14, reduces macrophage viability. Their effects are mimicked by the selective activation of sst1 and sst2 using CH-275 and SMS 201-995/L-779,976, respectively. Further, both sst1- and sst2-mediated effects are reversed by the sst1 antagonist SRA-880 or the sst2 antagonist CYN, respectively. CH-275, SMS 201-995 and L-779,976, but not SRIF-14, decrease both mRNA expression and secretion of the monocyte chemotactic protein-1. In addition, SRIF-14, CH-275, SMS 201-995 and L-779,976 decrease interleukine-8 secretion while they do not affect interleukine-8 mRNA expression. In contrast, SRIF-14 and sst1/sst2 agonists do not affect the secretion of matrix metalloproteinase-9. Collectively, our results suggest that the SRIF system, through sst1 and sst2, exerts mainly an immunosuppressive effect in human macrophages and may, therefore, represent a therapeutic window that can be exploited for the development of new strategies in pharmacological therapy of inflammation.L'articolo è disponibile sul sito dell'editore http://leukocytebiology.org/default.asp

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London