325 research outputs found
Operation Moshtarak and the manufacture of credible, “heroic” warfare
Richard Lance Keeble argues that Fleet Street’s coverage of the Afghan conflict has served largely to promote the interests of the military/industrial/media complex – and marginalise the views of the public who have consistently appealed in polls for the troops to be brought back hom
Diverse bacterial species contribute to antibiotic-associated diarrhoea and gastrointestinal damage
Objectives: Antibiotic-associated diarrhoea (AAD) caused by C. difficile is one of the most common nosocomial infections, however, little is known about infections related to antimicrobial use for pathogens other than C. difficile. We therefore aimed to provide insight into other bacterial causes of AAD, and how infection with these pathogens causes damage in the dysbiotic gut.
Methods: Clinical isolates from C. difficile-negative AAD patients were whole genome sequenced for in silico analysis of potential virulence factors and antimicrobial resistance determinants. A mouse model of infection was developed to assess the capacity of these isolates to cause gastrointestinal damage, which was analysed by studying specific markers in the gastrointestinal mucosa of infected mice.
Results: Several bacterial pathogens were isolated from patients with C. difficile-negative AAD. Each isolate showed the potential for virulence based on encoded virulence factors, as well as most showing antimicrobial resistance in vitro. Isolates of Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae were tested in the mouse model of infection, inducing damage primarily in the small intestine, affecting adherens junction integrity, cellular polarity, and cellular proliferation.
Conclusions: Several pathogens of clinical importance other than C. difficile are able to cause gastrointestinal infection following antimicrobial-mediated dysbiosis. The virulence potential and multidrug resistance identified in these isolates illuminates the importance of further diagnostic screening in cases of C. difficile-negative AAD
A rapid semi-quantitative screening method to assess chemicals present in heated e-liquids and e-cigarette aerosols
Electronic cigarettes (e-cigarettes) lack regulatory status as therapeutic products in all jurisdictions worldwide. They are potentially unsafe consumer products, with significant evidence they pose a risk to human health. Therefore, developing rapid, economical test methods to assess the chemical composition of e-liquids in heated and unheated forms and the aerosols produced by e-cigarettes is crucial. Four different e-liquids were heated using two different methods: (1) “typical” vaping using an e-cigarette device, by cycling “on” for 3 s every minute for 2 h (e-liquid obtained from remainder in the tank and aerosol collected in an impinger), and (2) “accelerated” heating, using an e-cigarette coil submerged in e-liquid and heating in short 20 s bursts on then 20 s off for 2 min only (liquid traps aerosol produced). All e-liquids were then analysed to test for the presence and quantity of 13 chemicals by gas chromatography–mass spectrometry and compared to an unheated sample. E-liquids heated with the accelerated method showed a comparable trend to the typical heating method, i.e. increase or decrease in chemical compound quantity, for more than two-thirds of the detected compounds analysed over all e-liquids. Six chemicals were detected as aerosol from the impinger fluid with the typical heating method at negligible levels. We propose that this accelerated version of the typical vaping method could form the basis of a standardized screening tool to test heated e-liquids (and e-cigarette aerosols) for harmful or banned substances. This will ensure that only approved products reach the consumer and reduce potential e-cigarette harm.</p
Avian malaria is absent in juvenile colonial herons (Ardeidae) but not Culex pipiens mosquitoes in the Camargue, Southern France
Apicomplexan blood parasites Plasmodium and Haemoproteus (together termed “Avian malaria”) and Leucocytozoon are widespread, diverse vector-transmitted blood parasites of birds, and conditions associated with colonial nesting in herons (Ardeidae) and other waterbirds appear perfect for their transmission. Despite studies in other locations reporting high prevalence of parasites in juvenile herons, juvenile Little Egrets (Egretta garzetta) previously tested in the Camargue, Southern France, had a total absence of malaria parasites. This study tested the hypotheses that this absence was due to insufficient sensitivity of the tests of infection; an absence of infective vectors; or testing birds too early in their lives. Blood was sampled from juveniles of four species shortly before fledging: Little Egret (n = 40), Cattle Egret (Bubulcus ibis; n = 40), Black-crowned Night-Heron (Nycticorax nycticorax, n = 40), and Squacco Heron (Ardeola ralloides; n = 40). Sensitive nested-Polymerase Chain Reaction was used to test for the presence of parasites in both birds and host-seeking female mosquitoes captured around the colonies. No malaria infection was found of in any of the heron species. Four different lineages of Plasmodium were detected in pooled samples of female Culex pipiens mosquitoes, including two in potentially infective mosquitoes. These results confirm that the absence of malaria parasites previously demonstrated in Little Egret is not due to methodological limitations. Although the prevalence of infection in mosquitoes was low, conditions within the colonies were suitable for transmission of Plasmodium. These colonial heron species may have evolved strategies for resisting malaria infection through physiological or behavioral mechanisms
The impact of tick-borne pathogen infection in Indian bovines is determined by host type but not the genotype of Theileria annulata
Tick-borne pathogens (TBP) are a major source of production loss and a welfare concern in livestock across the globe. Consequently, there is a trade-off between keeping animals that are tolerant to TBP infection, but are less productive than more susceptible breeds. Theileria annulata is a major TBP of bovines, with different host types (i.e. exotic and native cattle breeds, and buffalo) displaying demonstrable differences in clinical susceptibility to infection. However, the extent to which these differences are driven by genetic/physiological differences between hosts, or by different parasite populations/genotypes preferentially establishing infection in different host breeds and species is unclear. In this study, three different bovine host types in India were blood sampled to test for the presence of various TBP, including Theileria annulata, to determine whether native cattle (Bos indicus breeds), crossbreed cattle (Bos taurus x Bos indicus breeds) or water buffalo (Bubalus bubalis) differ in the physiological consequences of infection. Population genetic analyses of T. annulata isolated from the three different host types was also performed, using a panel of mini- and micro-satellite markers, to test for sub-structuring of the parasite population among host types. We discovered that compared to other host types, “carrier” crossbreed cattle showed a higher level of haematological pathology when infected with T. annulata. Despite this finding, we found no evidence for differences in the genotypes of T. annulata infecting different host types, although buffalo appeared to harbour fewer mixed parasite genotype infections, indicating they are not the major reservoir of parasite diversity. The apparent tolerance/resistance of native breed cattle and buffalo to the impacts of T. annulata infection is thus most likely to be driven by host genotype, rather than differences in the parasite population. Our results suggest that an improved understanding of the genetic factors that underpin disease resistance could help to ameliorate future economic loss due to TBP or tropical theileriosis
Rapid conjugation of antibodies to toxins to select candidates for the development of anticancer Antibody-Drug conjugates (ADcs)
Antibody-Drug Conjugates (ADCs) developed as a targeted treatment approach to deliver toxins directly to cancer cells are one of the fastest growing classes of oncology therapeutics, with eight ADCs and two immunotoxins approved for clinical use. However, selection of an optimum target and payload combination, to achieve maximal therapeutic efficacy without excessive toxicity, presents a significant challenge. We have developed a platform to facilitate rapid and cost-effective screening of antibody and toxin combinations for activity and safety, based on streptavidin-biotin conjugation. For antibody selection, we evaluated internalization by target cells using streptavidin-linked antibodies conjugated to biotinylated saporin, a toxin unable to cross cell membranes. For payload selection, we biotinylated toxins and conjugated them to antibodies linked to streptavidin to evaluate antitumour activity and pre-clinical safety. As proof of principle, we compared trastuzumab conjugated to emtansine via streptavidin-biotin (Trastuzumab-SB-DM1) to the clinically approved trastuzumab emtansine (T-DM1). We showed comparable potency in reduction of breast cancer cell survival in vitro and in growth restriction of orthotopic breast cancer xenografts in vivo. Our findings indicate efficient generation of functionally active ADCs. This approach can facilitate the study of antibody and payload combinations for selection of promising candidates for future ADC development
Baseline Psychological Traits Contribute to Lake Louise Acute Mountain Sickness Score at High Altitude
Talks, Benjamin James, Catherine Campbell, Stephanie J. Larcombe, Lucy Marlow, Sarah L. Finnegan, Christopher T. Lewis, Samuel J.E. Lucas, Olivia K. Harrison, and Kyle T.S. Pattinson. Baseline psychological traits contribute to Lake Louise Acute Mountain Sickness score at high altitude. High Alt Med Biol. 23:69-77, 2022. Background: Interoception refers to an individual's ability to sense their internal bodily sensations. Acute mountain sickness (AMS) is a common feature of ascent to high altitude that is only partially explained by measures of peripheral physiology. We hypothesized that interoceptive ability may explain the disconnect between measures of physiology and symptom experience in AMS. Methods: Two groups of 18 participants were recruited to complete a respiratory interoceptive task three times at 2-week intervals. The control group remained in Birmingham (140 m altitude) for all three tests. The altitude group completed test 1 in Birmingham, test 2 the day after arrival at 2,624 m, and test 3 at 2,728 m after an 11-day trek at high altitude (up to 4,800 m). Results: By measuring changes to metacognitive performance, we showed that acute ascent to altitude neither presented an interoceptive challenge, nor acted as interoceptive training. However, AMS symptom burden throughout the trek was found to relate to sea level measures of anxiety, agoraphobia, and neuroticism. Conclusions: This suggests that the Lake Louise AMS score is not solely a reflection of physiological changes on ascent to high altitude, despite often being used as such by researchers and commercial trekking companies alike.
Keywords: acute mountain sickness; altitude; breathlessness; exercise; filter detection task; interoceptio
Lifestyle behaviours of young adult survivors of childhood cancer
This cross-sectional study collected baseline data on the health behaviours of a large population of survivors of childhood cancer in the UK, aged 18–30 years, compared with those of sex- and age-matched controls. Data from 178 young adult survivors of childhood cancer, diagnosed and treated at Bristol Children's Hospital, 184 peers from the survivors' GP practices and 67 siblings were collected by postal questionnaire. Conditional logistic regression analysis showed that, for matched sets of survivors and controls, survivors of a variety of childhood cancers reported lower levels of alcohol consumption (P=0.005), lower levels of cigarette smoking (P=0.027) and lower levels of recreational drug use (P=0.001) than controls. Analysis of matched sets of survivors and siblings showed similar trends but no significant differences. A health behaviour index for each participant was constructed from the data collected on five key health behaviours which influence future health status. Comparison of the means for each case group showed that survivors of childhood cancer were leading healthier lives than controls or siblings. This finding was expressed most clearly as the difference in the means of the health behaviour index for each case group, derived from five health behaviours (one-way ANOVA, P<0.001)
Hypoxia Promotes Immune Evasion by Triggering β-glucan Masking on the Candida albicans Cell Surface via Mitochondrial and cAMP-Protein Kinase A Signaling
We are very grateful to the members of our Iain Fraser Cytometry Centre and Microscopy and Histology Core Facility for their superb help, advice and support. We also thank our generous colleagues in the Candida community, and in particular Ana Traven, Jan Quinn, Guanghua Huang, Suzanne Noble, Donna MacCallum, Liz Johnson, Karl Kuchler, Patrick van Dijck, Rich Calderone and Malcolm Whiteway for providing strains used in this study. This work was funded by grants from the UK Medical Research Council [www.mrc.ac.uk], to AJPB, NARG, LPE, MN (MR/M026663/1), and by PhD studentships from the University of Aberdeen to AP, DL. The work was also supported by the Wellcome Trust [www.wellcome.ac.uk], NARG, GDB, AJPB (097377) and GDB (102705); and by the Medical Research Council Centre for Medical Mycology and the University of Aberdeen (MR/N006364/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
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