Profiles of Serum Cytokines in Acute Drug-Induced Liver Injury and Their Prognostic Significance

Drug-induced liver injury (DILI) is the most common cause of acute liver failure in the United-States. The aim of the study was to describe serum immune profiles associated with acute DILI, to investigate whether there are profiles associated with clinical features or types of DILI and/or with prognosis, and to assess temporal changes in levels. Twenty-seven immune analytes were measured in the sera of 78 DILI subjects in the Drug-Induced Liver Injury Network (DILIN) and compared with 40 healthy controls. Immune analytes (14 cytokines, 7 chemokines and 6 growth factors) were measured by BioPlex multiplex ELISA at DILI onset and after 6 months. A modeling process utilizing immune principles was used to select a final set of variables among 27 immune analytes and several additional clinical lab values for prediction of early death (within 6 months of DILI onset). Nineteen of the 27 immune analytes were differentially expressed among healthy control, DILI onset and 6-month cohorts. Disparate patterns of immune responses, especially innate and adaptive cellular (mostly TH17) immunity were evident. Low values of four immune analytes (IL-9, IL-17, PDGF-bb and RANTES) and serum albumin are predictive of early death [PPV = 88% (95% CI, 65%-100%), NPV = 97% (95% CI, 93%-100%), accuracy = 96% (95% CI, 92%-100%)].

Conclusions

Acute DILI is associated with robust and varying immune responses. High levels of expression of cytokines associated with innate immunity are associated with a poor prognosis, whereas high levels of expression of adaptive cytokines are associated with good long-term prognosis and eventual recovery. Serum immune analyte profiles at DILI onset appear to be of prognostic, and perhaps, diagnostic significance.     

Imbricaric Acid and Perlatolic Acid: Multi-Targeting Anti-Inflammatory Depsides from Cetrelia monachorum

In vitro screening of 17 Alpine lichen species for their inhibitory activity against 5-lipoxygenase, microsomal prostaglandin E₂ synthase-1 and nuclear factor kappa B revealed Cetrelia monachorum (Zahlbr.) W.L. Culb. & C.F. Culb. As conceivable source for novel anti-inflammatory compounds. Phytochemical investigation of the ethanolic crude extract resulted in the isolation and identification of 11 constituents, belonging to depsides and derivatives of orsellinic acid, olivetolic acid and olivetol. The two depsides imbricaric acid (4) and perlatolic acid (5) approved dual inhibitory activities on microsomal prostaglandin E₂ synthase-1 (IC₅₀ = 1.9 and 0.4 µM, resp.) and on 5-lipoxygenase tested in a cell-based assay (IC₅₀ = 5.3 and 1.8 µM, resp.) and on purified enzyme (IC₅₀ = 3.5 and 0.4 µM, resp.). Additionally, these two main constituents quantified in the extract with 15.22% (4) and 9.10% (5) showed significant inhibition of tumor necrosis factor alpha-induced nuclear factor kappa B activation in luciferase reporter cells with IC₅₀ values of 2.0 and 7.0 µM, respectively. In a murine in vivo model of inflammation, 5 impaired the inflammatory, thioglycollate-induced recruitment of leukocytes to the peritoneum. The potent inhibitory effects on the three identified targets attest 4 and 5 a pronounced multi-target anti-inflammatory profile which warrants further investigation on their pharmacokinetics and in vivo efficacy.     

What Are the Health Benefits of Active Travel? A Systematic Review of Trials and Cohort Studies

Background

Increasing active travel (primarily walking and cycling) has been widely advocated for reducing obesity levels and achieving other population health benefits. However, the strength of evidence underpinning this strategy is unclear. This study aimed to assess the evidence that active travel has significant health benefits.

Methods

The study design was a systematic review of (i) non-randomised and randomised controlled trials, and (ii) prospective observational studies examining either (a) the effects of interventions to promote active travel or (b) the association between active travel and health outcomes. Reports of studies were identified by searching 11 electronic databases, websites, reference lists and papers identified by experts in the field. Prospective observational and intervention studies measuring any health outcome of active travel in the general population were included. Studies of patient groups were excluded.

Results

Twenty-four studies from 12 countries were included, of which six were studies conducted with children. Five studies evaluated active travel interventions. Nineteen were prospective cohort studies which did not evaluate the impact of a specific intervention. No studies were identified with obesity as an outcome in adults; one of five prospective cohort studies in children found an association between obesity and active travel. Small positive effects on other health outcomes were found in five intervention studies, but these were all at risk of selection bias. Modest benefits for other health outcomes were identified in five prospective studies. There is suggestive evidence that active travel may have a positive effect on diabetes prevention, which may be an important area for future research.

Conclusions

Active travel may have positive effects on health outcomes, but there is little robust evidence to date of the effectiveness of active transport interventions for reducing obesity. Future evaluations of such interventions should include an assessment of their impacts on obesity and other health outcomes.     

Novel Methods for Analysing Bacterial Tracks Reveal Persistence in Rhodobacter sphaeroides

Tracking bacteria using video microscopy is a powerful experimental approach to probe their motile behaviour. The trajectories obtained contain much information relating to the complex patterns of bacterial motility. However, methods for the quantitative analysis of such data are limited. Most swimming bacteria move in approximately straight lines, interspersed with random reorientation phases. It is therefore necessary to segment observed tracks into swimming and reorientation phases to extract useful statistics. We present novel robust analysis tools to discern these two phases in tracks. Our methods comprise a simple and effective protocol for removing spurious tracks from tracking datasets, followed by analysis based on a two-state hidden Markov model, taking advantage of the availability of mutant strains that exhibit swimming-only or reorientating-only motion to generate an empirical prior distribution. Using simulated tracks with varying levels of added noise, we validate our methods and compare them with an existing heuristic method. To our knowledge this is the first example of a systematic assessment of analysis methods in this field. The new methods are substantially more robust to noise and introduce less systematic bias than the heuristic method. We apply our methods to tracks obtained from the bacterial species Rhodobacter sphaeroides and Escherichia coli. Our results demonstrate that R. sphaeroides exhibits persistence over the course of a tumbling event, which is a novel result with important implications in the study of this and similar species.     

Platelet Activation Determines Angiopoietin-1 and VEGF Levels in Malaria: Implications for Their Use as Biomarkers

Introduction

The angiogenic proteins angiopoietin (Ang)-1, Ang-2 and vascular endothelial growth factor (VEGF) are regulators of endothelial inflammation and integrity. Since platelets store large amounts of Ang-1 and VEGF, measurement of circulation levels of these proteins is sensitive to platelet number, in vivo platelet activation and inadvertent platelet activation during blood processing. We studied plasma Ang-1, Ang-2 and VEGF levels in malaria patients, taking the necessary precautions to avoid ex vivo platelet activation, and related plasma levels to platelet count and the soluble platelet activation markers P-selectin and CXCL7.

Methods

Plasma levels of Ang-1, Ang-2, VEGF, P-selectin and CXCL7 were measured in CTAD plasma, minimizing ex vivo platelet activation, in 27 patients with febrile Plasmodium falciparum malaria at presentation and day 2 and 5 of treatment and in 25 healthy controls.

Results

Levels of Ang-1, Ang-2 and VEGF were higher at day 0 in malaria patients compared to healthy controls. Ang-2 levels, which is a marker of endothelial activation, decreased after start of antimalarial treatment. In contrast, Ang-1 and VEGF plasma levels increased and this corresponded with the increase in platelet number. Soluble P-selectin and CXCL7 levels followed the same trend as Ang-1 and VEGF levels. Plasma levels of these four proteins correlated strongly in malaria patients, but only moderately in controls.

Conclusion

In contrast to previous studies, we found elevated plasma levels of Ang-1 and VEGF in patients with malaria resulting from in vivo platelet activation. Ang-1 release from platelets may be important to dampen the disturbing effects of Ang-2 on the endothelium. Evaluation of plasma levels of these angiogenic proteins requires close adherence to a stringent protocol to minimize ex vivo platelet activation.     

Control of (Multi)Drug Resistance and Tuberculosis Incidence over 23 Years in the Context of a Well-Supported Tuberculosis Programme in Rural Malawi

Background

The rise in tuberculosis (TB) incidence following generalized HIV epidemics can overwhelm TB control programmes in resource-limited settings, sometimes accompanied by rising rates of drug resistance. This has led to claims that DOTS-based TB control has failed in such settings. However, few studies have described the effect of a sustained and well-supported DOTS programme on TB incidence and drug resistance over a long period. We present long-term trends in incidence and drug resistance in rural Malawi.

Methods

Karonga District in northern Malawi has an adult HIV prevalence of ∼10%. A research group, the Karonga Prevention Study, collaborates with the National Tuberculosis Programme to support core TB control activities. Bacteriological, demographic and clinical (including HIV status) information from all patients starting TB treatment in the District have been recorded since 1988. During that period isolates from each culture-positive TB patient were exported for drug sensitivity testing. Antiretroviral therapy (ART) has been widely available since 2005.

Results

Incidence of new smear-positive adult TB peaked at 124/100,000/year in the mid-90s, but has since fallen to 87/100,000/year. Drug sensitivity information was available for 95% (3132/3307) of all culture-positive cases. Initial resistance to isoniazid was around 6% with no evidence of an increase. Fewer than 1% of episodes involved a multi-drug resistant strain.

Discussion

In this setting with a generalised HIV epidemic and medium TB burden, a well-supported DOTS programme enhanced by routine culture and drug sensitivity testing may well have reduced TB incidence and maintained drug resistance at low levels.     

Functional and Structural Neural Network Characterization of Serotonin Transporter Knockout Rats

Brain serotonin homeostasis is crucially maintained by the serotonin transporter (5-HTT), and its down-regulation has been linked to increased vulnerability for anxiety- and depression-related behavior. Studies in 5-HTT knockout (5-HTT^-/-) rodents have associated inherited reduced functional expression of 5-HTT with increased sensitivity to adverse as well as rewarding environmental stimuli, and in particular cocaine hyperresponsivity. 5-HTT down-regulation may affect normal neuronal wiring of implicated corticolimbic cerebral structures. To further our understanding of its contribution to potential alterations in basal functional and structural properties of neural network configurations, we applied resting-state functional MRI (fMRI), pharmacological MRI of cocaine-induced activation, and diffusion tensor imaging (DTI) in 5-HTT^-/- rats and wild-type controls (5-HTT^+/+). We found that baseline functional connectivity values and cocaine-induced neural activity within the corticolimbic network was not significantly altered in 5-HTT^-/- versus 5-HTT^+/+ rats. Similarly, DTI revealed mostly intact white matter structural integrity, except for a reduced fractional anisotropy in the genu of the corpus callosum of 5-HTT^-/- rats. At the macroscopic level, analyses of complex graphs constructed from either functional connectivity values or structural DTI-based tractography results revealed that key properties of brain network organization were essentially similar between 5-HTT^+/+ and 5-HTT^-/- rats. The individual tests for differences between 5-HTT^+/+ and 5-HTT^-/- rats were capable of detecting significant effects ranging from 5.8% (fractional anisotropy) to 26.1% (pharmacological MRI) and 29.3% (functional connectivity). Tentatively, lower fractional anisotropy in the genu of the corpus callosum could indicate a reduced capacity for information integration across hemispheres in 5-HTT^-/- rats. Overall, the comparison of 5-HTT^-/- and wild-type rats suggests mostly limited effects of 5-HTT genotype on MRI-based measures of brain morphology and function.     

Use of a Modified Pediatric Early Warning Score in a Department of Pediatric and Adolescent Medicine

Background

Several versions of the Pediatric Early Warning Score (PEWS) exist, but there is limited information available on the use of such systems in different contexts. In the present study, we aimed to examine the relationship between a modified version of The Brighton Paediatric Early Warning Score (PEWS) and patient characteristics in a Norwegian department of pediatric and adolescent medicine. In addition, we sought to establish guidelines for escalation in patient care based on the PEWS in our patient population.

Methods

The medical records of patients referred for acute care from March to May 2011 were retrospectively reviewed. Children with a PEWS ≥3 were compared to children with a PEWS 0–2 with regard to age, diagnostic group and indicators of severe disease.

Results

A total of 761 patients (0−18 years of age) were included in the analysis. A younger age and diagnostic groups such as lower airway and cardiovascular disease were associated with PEWS ≥3. Upper airway disease and minor injury were more frequent in patients with PEWS 0−2. Children with PEWS ≥3 received fluid resuscitation, intravenous antibiotics, and oxygen supplementation, and were transferred to a higher level of care more often than children with PEWS 0−2.

Conclusions

A PEWS ≥3 was associated with severe illnesses and surrogate markers of cardio-respiratory compromise. Patients with PEWS ≥3 should be carefully monitored to prevent further deterioration.     

Modeling Long-Term Host Cell-Giardia lamblia Interactions in an In Vitro Co-Culture System

Globally, there are greater than 700,000 deaths per year associated with diarrheal disease. The flagellated intestinal parasite, Giardia lamblia, is one of the most common intestinal pathogens in both humans and animals throughout the world. While attached to the gastrointestinal epithelium, Giardia induces epithelial cell apoptosis, disrupts tight junctions, and increases intestinal permeability. The underlying cellular and molecular mechanisms of giardiasis, including the role lamina propria immune cells, such as macrophages, play in parasite control or clearance are poorly understood. Thus far, one of the major obstacles in ascertaining the mechanisms of Giardia pathology is the lack of a functionally relevant model for the long-term study of the parasite in vitro. Here we report on the development of an in vitro co-culture model which maintains the basolateral-apical architecture of the small intestine and allows for long-term survival of the parasite. Using transwell inserts, Caco-2 intestinal epithelial cells and IC-21 macrophages are co-cultured in the presence of Giardia trophozoites. Using the developed model, we show that Giardia trophozoites survive over 21 days and proliferate in a combination media of Caco-2 cell and Giardia medium. Giardia induces apoptosis of epithelial cells through caspase-3 activation and macrophages do not abrogate this response. Additionally, macrophages induce Caco-2 cells to secrete the pro-inflammatory cytokines, GRO and IL-8, a response abolished by Giardia indicating parasite induced suppression of the host immune response. The co-culture model provides additional complexity and information when compared to a single-cell model. This model will be a valuable tool for answering long-standing questions on host-parasite biology that may lead to discovery of new therapeutic interventions.