Integration of multiple flexible electrodes for real-time detection of barrier formation with spatial resolution in a gut-on-chip system

In healthy individuals, the intestinal epithelium forms a tight barrier to prevent gut bacteria from reaching blood circulation. To study the effect of probiotics, dietary compounds and drugs on gut barrier formation and disruption, human gut epithelial and bacterial cells can be cocultured in an in vitro model called the human microbial crosstalk (HuMiX) gut-on-a-chip system. Here, we present the design, fabrication and integration of thin-film electrodes into the HuMiX platform to measure transepithelial electrical resistance (TEER) as a direct readout on barrier tightness in real-time. As various aspects of the HuMiX platform have already been set in their design, such as multiple compressible layers, uneven surfaces and nontransparent materials, a novel fabrication method was developed whereby thin-film metal electrodes were first deposited on flexible substrates and sequentially integrated with the HuMiX system via a transfer-tape approach. Moreover, to measure localized TEER along the cell culture chamber, we integrated multiple electrodes that were connected to an impedance analyzer via a multiplexer. We further developed a dynamic normalization method because the active measurement area depends on the measured TEER levels. The fabrication process and system setup can be applicable to other barrier-on-chip systems. As a proof-of-concept, we measured the barrier formation of a cancerous Caco-2 cell line in real-time, which was mapped at four spatially separated positions along the HuMiX culture area.

Two-Photon Polymerization Printing with High Metal Nanoparticle Loading

Two-photon polymerization (2PP) is an efficient technique to achieve high-resolution, three-dimensional (3D)-printed complex structures. However, it is restricted to photocurable monomer combinations, thus presenting constraints when aiming at attaining functionally active resist formulations and structures. In this context, metal nanoparticle (NP) integration as an additive can enable functionality and pave the way to more dedicated applications. Challenges lay on the maximum NP concentrations that can be incorporated into photocurable resist formulations due to the laser-triggered interactions, which primarily originate from laser scattering and absorption, as well as the limited dispersibility threshold. In this study, we propose an approach to address these two constraints by integrating metallic Rh NPs formed ex situ, purposely designed for this scope. The absence of surface plasmon resonance (SPR) within the visible and near-infrared spectra, coupled with the limited absorption value measured at the laser operating wavelength (780 nm), significantly limits the laser-induced interactions. Moreover, the dispersibility threshold is increased by engineering the NP surface to be compatible with the photocurable resin, permitting us to achieve concentrations of up to 2 wt %, which, to our knowledge, is significantly higher than the previously reported limit (or threshold) for embedded metal NPs. Another distinctive advantage of employing Rh NPs is their role as promising contrast agents for X-ray fluorescence (XRF) bioimaging. We demonstrated the presence of Rh NPs within the whole 2PP-printed structure and emphasized the potential use of NP-loaded 3D-printed nanostructures for medical devices.

Pre-oxygenation using high-flow nasal oxygen in parturients undergoing caesarean section in general anaesthesia: A prospective, multi-centre, pilot study

BACKGROUND

Parturients undergoing caesarean section in general anaesthesia have an increased risk of desaturating during anaesthesia induction. Pre- and peri-oxygenation with high-flow nasal oxygen prolong the safe apnoea time but data on parturients undergoing caesarean section under general anaesthesia are limited. This pilot study aimed to investigate the clinical effects and frequency of desaturation in parturients undergoing caesarean section in general anaesthesia pre- and peri-oxygenated with high-flow nasal oxygen and compare this to traditional pre-oxygenation using a facemask.

METHODS

In this prospective, non-randomised, multi-centre study we included pregnant women with a gestational age ≥30 weeks undergoing caesarean section under general anaesthesia. All parturients were asked to participate in the intervention group consisting of pre-oxygenation using high-flow nasal oxygen. Parturients declining participation were pre-oxygenated with a traditional facemask. Primary outcome was the proportion of parturients desaturating below 93% from start of pre-oxygenation until 1 min after tracheal intubation. Secondary outcomes investigated end-tidal oxygen concentrations after tracheal intubation and the proportion of parturients with signs of regurgitation.

RESULTS

A total of 34 parturients were included, 25 pre- and peri-oxygenated with high-flow nasal oxygen and 9 pre-oxygenated with facemask. No difference in patient or airway characteristics could be seen except for a higher BMI in the high-flow nasal oxygen group (31.4 kg m-2 [4.7] vs. 27.7 kg m-2 [3.1]; p = .034). No woman in any of the two groups desaturated below 93%. The lowest peripheral oxygen saturation observed, in any parturient, was 97%. There was no difference detected in end-tidal oxygen concentration after tracheal intubation, 87% (6) in the high-flow nasal oxygen group vs 80% (15) in the facemask group (p = .308). No signs of regurgitation, in any parturient, were seen.

CONCLUSION

Pre- and peri-oxygenation with high-flow nasal oxygen maintain adequate oxygen saturation levels during induction of anaesthesia also in parturients. Regurgitation of gastric content did not occur in any parturient and no other safety concerns were observed in this pilot study.

A highly challenging balance training intervention for people with multiple sclerosis: a feasibility trial

BACKGROUND

Balance training interventions with a gradual progression of difficulty and highly challenging tasks designed specifically for people with multiple sclerosis (MS) are rare. The objective was to adapt a balance training intervention originally developed for Parkinson's disease through a co-design process and then conduct a pilot trial in MS to evaluate the feasibility of a large, full-scale study.

METHODS

Twelve people with MS with mild to moderate overall MS-disability were included in this single-group feasibility trial. Participants received one-hour training sessions twice or three times weekly for 10 weeks. The assessment included tests of physical and cognitive functioning and patient-reported quality of life-related outcomes. Data on feasibility aspects were collected at baseline and follow-up assessments and three times during the intervention period to inform the recruitment process, as well as to monitor retention and inclusion rates, study procedures, intervention delivery, and dynamic changes in the selected potential outcome measures. Progression criteria were used to determine whether to proceed to a full-scale trial. Descriptive statistics were used to present the data.

RESULTS

Out of six progression criteria, only retention and attendance at training sessions were not met. Reasons reported for not completing the intervention period mainly depended on external circumstances beyond the control of the study. In contrast, study procedures, intervention delivery, and intervention content (progression, adjustment, and control of challenge level of exercises) were considered feasible for a future, full-scale trial. The Mini-BESTest, which was used for the assessment of balance control, was considered suitable as the primary outcome in a full-scale trial with no ceiling or floor effects. Further, the Mini-BESTest showed a positive trend in outcome response with a median difference of 3.5 points between baseline and follow-up assessments. The power calculation performed suggests a feasible number of participants for recruitment.

CONCLUSIONS

Overall trial aspects and intervention delivery were deemed feasible for a full-scale trial, but adjustments are needed to increase retention and attendance.

P08.01.A Evaluation of a multimodal rehabilitative palliative care programme for patients with high-grade glioma and their family caregivers

Background

When a family member is diagnosed with high-grade glioma, it not only affects the patient, but also the entire family. Due to an intense disease- and treatment trajectory and a complex symptom burden, patients often depend on support from their family caregivers. Family caregivers struggle to adjust to a change in family roles. Hence, proper information and supportive care are essential for patients and family caregivers to help them manage their changed life situations.

Material and Methods

This was a longitudinal multi-methods study applying qualitative interview data and quantitative survey data to explore and evaluate the programme. A multimodal rehabilitative palliative care programme was designed by a multidisciplinary cross-sectoral team of clinical specialists and researchers. The purpose was to provide patients and family caregivers with information and facilitate the exchange of perspectives and experiences among peers e.g. on daily living and family function. Additionally, to provide participants with strategies to manage this life transition

Results

Adult patients with high-grade glioma (n = 17) and their family caregivers (n = 16) completed a 4-day residential programme and a 2-day follow-up programme 3 months later. Qualitative data were collected during focus group interviews (n = 4) with patients and caregivers. Participants responded to self-developed questionnaires after each programme, scoring all sessions for relevance and satisfaction on a 5-point Likert scale (0, not relevant/satisfied; 5, very relevant/highly satisfied). Three themes emerged in the focus group interviews: 1) meeting peers strengthens social well-being, 2) the value of information and focusing on individual needs, and 3) accepting life as an unpredictable passage. The mean overall satisfaction score was 4.80 (standard deviation [SD], 0.55) for the initial 4-day programme and 4.28 (SD, 0.83) for the follow-up programme.

Conclusion

The multimodal rehabilitative palliative care programme addressed unmet patient and caregiver needs and may have the potential to enhance family function or coping mastery. The programme was feasible, and all sessions received high scores for satisfaction and relevance, as well as positive evaluations. Qualitative findings confirmed the value of individualized information and peer interactions. In particular, peer-to-peer interventions for family caregivers may address individual support needs, including sharing experiences and strengthening social well-being.

Organ-on-a-chip technology: a novel approach to investigate cardiovascular diseases

The development of organs-on-chip (OoC) has revolutionized in vitro cell-culture experiments by allowing a better mimicry of human physiology and pathophysiology that has consequently led researchers to gain more meaningful insights into disease mechanisms. Several models of hearts-on-chips and vessels-on-chips have been demonstrated to recapitulate fundamental aspects of the human cardiovascular system in the recent past. These 2D and 3D systems include synchronized beating cardiomyocytes in hearts-on-chips and vessels-on-chips with layer-based structures and the inclusion of physiological and pathological shear stress conditions. The opportunities to discover novel targets and to perform drug testing with chip-based platforms have substantially enhanced, thanks to the utilization of patient-derived cells and precise control of their microenvironment. These organ models will provide an important asset for future approaches to personalized cardiovascular medicine and improved patient care. However, certain technical and biological challenges remain, making the global utilization of OoCs to tackle unanswered questions in cardiovascular science still rather challenging. This review article aims to introduce and summarize published work on hearts- and vessels-on chips but also to provide an outlook and perspective on how these advanced in vitro systems can be used to tailor disease models with patient-specific characteristics.

In-Line Analysis of Organ-on-Chip Systems with Sensors: Integration, Fabrication, Challenges, and Potential

Organ-on-chip systems are promising new in vitro research tools in medical, pharmaceutical, and biological research. Their main benefit, compared to standard cell culture platforms, lies in the improved in vivo resemblance of the cell culture environment. A critical aspect of these systems is the ability to monitor both the cell culture conditions and biological responses of the cultured cells, such as proliferation and differentiation rates, release of signaling molecules, and metabolic activity. Today, this is mostly done using microscopy techniques and off-chip analytical techniques and assays. Integrating in situ analysis methods on-chip enables improved time resolution, continuous measurements, and a faster read-out; hence, more information can be obtained from the developed organ and disease models. Integrated electrical, electrochemical, and optical sensors have been developed and used for chemical analysis in lab-on-a-chip systems for many years, and recently some of these sensing principles have started to find use in organ-on-chip systems as well. This perspective review describes the basic sensing principles, sensor fabrication, and sensor integration in organ-on-chip systems. The review also presents the current state of the art of integrated sensors and discusses future potential. We bring a technological perspective, with the aim of introducing in-line sensing and its promise to advance organ-on-chip systems and the challenges that lie in the integration to researchers without expertise in sensor technology.

A microscopy-compatible temperature regulation system for single-cell phenotype analysis - demonstrated by thermoresponse mapping of microalgae

This work describes a programmable heat-stage compatible with in situ microscopy for the accurate provision of spatiotemporally defined temperatures to different microfluidic devices. The heat-stage comprises an array of integrated thin-film Joule heaters and resistance temperature detectors (RTDs). External programming of the heat-stage is provided by a custom software program connected to temperature controllers and heater-sensor pairs. Biologically relevant (20-40 °C) temperature profiles can be supplied to cells within microfluidic devices as spatial gradients (0.5-1.5 °C mm-1) or in a time-varying approach via e.g. step-wise or sinusoidally varying profiles with negligible temperature over-shoot. Demonstration of the device is achieved by exposing two strains of the coral symbiont Symbiodinium to different temperature profiles while monitoring their single-cell photophysiology via chlorophyll fluorometry. This revealed that photophysiological responses to temperature depended on the exposure duration, exposure magnitude and strain background. Moreover, thermal dose analysis suggested that cell acclimatisation occurs under longer temperature (6 h) exposures but not under shorter temperature exposures (15 min). As the thermal sensitivity of Symbiodinium mediates the thermal tolerance in corals, our versatile technology now provides unique possibilities to research this interdependency at single cell resolution. Our results also show the potential of this heat-stage for further applications in fields such as biotechnology and ecotoxicology.

Pair Correlation Analysis Maps the Dynamic Two-Dimensional Organization of Natural Killer Cell Receptors at the Synapse

In living systems, the contact between cells is the basis of recognition, differentiation, and orchestration of an immune response. Obstacles and barriers to biomolecular motion, especially for receptors at cellular synapses, critically control these functions by creating an anisotropic environment. Whereas conventional fluorescence fluctuation methods, such as fluorescence correlation spectroscopy or fluorescence recovery after photobleaching, can only measure the isotropic diffusion of molecules, the two-dimensional pair correlation function (2D-pCF) approach probes the anisotropic paths at different spatial locations within an image, allowing the creation of high-resolution maps that can visualize and quantify how molecules move in a living cell. In this work, we show how the 2D-pCF method maps the environment in cellular synapses as perceived by natural killer (NK) cell receptors. In cultured human HLA null 721.221 cells, 2D-pCF reveals the motion of inhibitory receptor HLA-Cw4-YFP coexpressed with KIR3DL1 to be highly directional around specific loci, while these restrictions were absent in the case of HLA-B51-YFP coexpressed with KIR2DL1. Further, in freshly isolated educated (H-2D^d) and uneducated (MHC^-/-) primary murine NK cells, the 2D-pCF method shows significant differences in the paths taken by activating receptor NKp46 and inhibitory receptor Ly49A in educated compared to uneducated cells. Altogether, we demonstrate that the 2D-pCF method is very powerful in informing about the spatial organization of motion in cells. Our data support the hypothesis that flexibility in the spatial arrangement of membrane receptors, that is, the absence of barriers, is crucial for NK cell function.

Non-cardioembolic TIA and ischemic stroke: Implications of severity

OBJECTIVES

Our purpose was to explore major vascular and bleeding outcomes in relation to risk and severity scores (ABCD2 or NIHSS) in patients with transient ischemic attack (TIA) or acute ischemic stroke (AIS).

METHODS

This nationwide observational study was based on data from 4 national registries. Outcomes were assessed by Kaplan-Meier and Cox regression analyses.

RESULTS

The total cohort comprised 21 268 patients (median age 73 years, 47.6% females). Based on ABCD2-score, the TIA-population (n = 10 174) was divided into low-risk (0-3 p, n = 3463) and high-risk (4-7 p, n = 6711). Based on NIHSS-score, the AIS-population (n = 11 454) was divided into minor (0-5 p, n = 8596), moderate (6-10 p, n = 1630) and severe (≥11 p, n = 1228). During follow-up (mean 1.7 years), the composite endpoint of stroke, myocardial infarction or death occurred in 3572 (16.5%) of all the patients, and major bleeding in 668 (3.1%) patients. Using low-risk TIA as reference, the adjusted hazard ratios (HR, 95% CI) of the composite endpoint were 1.41 (1.23-1.62) for high-risk TIA, 1.94 (1.70-2.22) for minor, 2.86 (2.45-3.34) for moderate and 4.18 (3.57-4.90) for severe stroke. When analyzed separately, the association with increased risk remained significant for stroke and death, but not for myocardial infarction. The HR of major bleeding were 1.31 (0.99-1.73) for high-risk TIA, 1.49 (1.13-1.95) for minor, 1.54 (1.08-2.21) for moderate and 2.10 (1.44-3.05) for severe stroke.

CONCLUSIONS

This study confirms the association between severity of the index ischemic stroke and risk of future major vascular and bleeding events, and highlights the increased risk also for patients with high-risk TIA.

Educated natural killer cells show dynamic movement of the activating receptor NKp46 and confinement of the inhibitory receptor Ly49A

Educated natural killer (NK) cells have inhibitory receptors specific for self major histocompatibility complex (MHC) class I molecules and kill cancer cells more efficiently than do NK cells that do not have such receptors (hyporesponsive NK cells). The mechanism behind this functional empowerment through education has so far not been fully described. In addition, distinctive phenotypic markers of educated NK cells at the single-cell level are lacking. We developed a refined version of the image mean square displacement (iMSD) method (called iMSD carpet analysis) and used it in combination with single-particle tracking to characterize the dynamics of the activating receptor NKp46 and the inhibitory receptor Ly49A on resting educated versus hyporesponsive murine NK cells. Most of the NKp46 and Ly49A molecules were restricted to microdomains; however, individual NKp46 molecules resided in these domains for shorter periods and diffused faster on the surface of educated, compared to hyporesponsive, NK cells. In contrast, the movement of Ly49A was more constrained in educated NK cells compared to hyporesponsive NK cells. Either disrupting the actin cytoskeleton or adding cholesterol to the cells prohibited activating signaling, suggesting that the dynamics of receptor movements within the cell membrane are critical for the proper activation of NK cells. The faster and more dynamic movement of NKp46 in educated NK cells may facilitate a swifter response to interactions with target cells.

Utilization and safety of proton-pump inhibitors and histamine-2 receptor antagonists in children and adolescents: an observational cohort study

BACKGROUND

Little is known about the use of acid-suppressing treatments and related safety events in children.

OBJECTIVE

This study compared patient characteristics and safety outcomes among children prescribed acid-suppressing drugs for the first time.

METHODS

The Health Improvement Network was used to determine the characteristics of children prescribed a proton pump inhibitor (PPI; esomeprazole or another PPI) or a histamine-2 receptor antagonist (H₂RA) by UK primary care physicians between October 2009 and September 2012. Pre-defined safety outcomes were compared among the treatment groups in up to 18 months of follow-up.

RESULTS

The cohorts comprised 8,172 patients on PPIs (including 24 patients on esomeprazole) and 7,905 on H₂RAs. The baseline characteristics were similar between cohorts, although the children in the PPI cohorts tended to be older. No safety outcomes occurred in the esomeprazole cohort. In the other-PPIs cohort, 92 safety outcomes occurred, most commonly gastroenteritis (n = 36; 39.1%). In the H₂RAs cohort, 193 safety outcomes occurred, most commonly gastroenteritis (n = 62; 32.1%). The incidence of most safety outcomes was higher in the H₂RAs cohort than in the other-PPIs cohort, including failure to thrive (3.11 [95% confidence interval (CI) = 2.25-4.28] vs 0.49 per 1,000 person-years [95% CI = 0.22-1.07]) and gastroenteritis (5.27 [95% CI = 4.11-6.75] vs 3.04 per 1,000 person-years [95% CI = 2.20-4.20]).

CONCLUSION

Esomeprazole is rarely prescribed to children when they first require acid-suppressing medication, compared with other PPIs/H₂RAs. Overall, more safety outcomes occurred in the H₂RAs cohort than in the PPI cohorts.

The HNF1A mutant Ala180Val: Clinical challenges in determining causality of a rare HNF1A variant in familial diabetes

AIMS

Heterozygous mutations in hepatocyte nuclear factor-1A (HNF1A) cause maturity-onset diabetes of the young type 3 (MODY3). Our aim was to compare two families with suspected dominantly inherited diabetes and a new HNF1A variant of unknown clinical significance.

METHODS

The HNF1A gene was sequenced in two independently recruited families from the Norwegian MODY Registry. Both familes were phenotyped clinically and biochemically. Microsatellite markers around and within the HNF1A locus were used for haplotyping. Chromosomal linkage analysis was performed in one family, and whole-exome sequencing was undertaken in two affected family members from each family. Transactivation activity, DNA binding and nuclear localization of wild type and mutant HNF-1A were assessed.

RESULTS

The novel HNF1A variant c.539C>T (p.Ala180Val) was found in both families. The variant fully co-segregated with diabetes in one family. In the other family, two subjects with diabetes mellitus and one with normal glucose levels were homozygous variant carriers. Chromosomal linkage of diabetes to the HNF1A locus or to other genomic regions could not be established. The protein functional studies did not reveal significant differences between wild type and variant HNF-1A. In each family, whole-exome sequencing failed to identify any other variant that could explain the disease.

CONCLUSIONS

The HNF1A variant p.Ala180Val does not seem to cause MODY3, although it may confer risk for type 2 diabetes mellitus. Our data demonstrate challenges in causality evaluation of rare variants detected in known diabetes genes.

Central regional anaesthesia in patients with aortic stenosis - a systematic review

INTRODUCTION

Aortic stenosis is a valvular lesion that poses several haemodynamic challenges for the anaesthesiologist. The use of central regional anaesthesia is traditionally regarded as contraindicated in patients with severe aortic stenosis due to its sympatholytic effect, potentially causing loss of vascular tone and ultimately diminished cardiac output. The aim of this paper was to review current literature to find evidence for or against the use of neuroaxial blockade in patients with aortic stenosis.

METHODS

We searched PubMed for relevant articles, using the following MeSH terms: "aortic valve stenosis", "epidural anesthesia", "spinal anesthesia" and "epidural analgesia". Only English language literature was included. Papers concerning aortic stenosis and obstetrical anaesthesia were excluded.

RESULTS

There are no randomised clinical trials on the subject, and existing literature is extremely sparse. Four retrospective studies and eight case reports counting a total of ten patients were found. All report successful use of neuroaxial blockade in patients with aortic stenosis, without severe haemodynamic alterations. In addition, data indicate that postepidural analgesia improves outcome compared with conventional analgesia.

CONCLUSIONS

To the best of our knowledge, there is no clinical evidence supporting the notion that central regional anaesthesia has any adverse effects on patients with aortic stenosis. Carefully managed neuroaxial blockade could become a useful alternative to general anaesthesia in this patient group. However, evidence is sparse and of questionable quality. Large prospective randomised clinical trials are required to establish best practise.

Durations of second stage of labor and pushing, and adverse neonatal outcomes: a population-based cohort study

OBJECTIVE

The associations between duration of second stage of labor, pushing time and risk of adverse neonatal outcomes are not fully established. Therefore, we aimed to examine such relationships.

STUDY DESIGN

A population-based cohort study including 42 539 nulliparous women with singleton infants born in cephalic presentation at ⩾37 gestational weeks, using the Stockholm-Gotland Obstetric Cohort, Sweden, and the Swedish Neonatal Quality Register, 2008 to 2013. Poisson regression was used to analyze estimated adjusted relative risks (RRs), with 95% confidence intervals (CIs). Outcome measures were umbilical artery acidosis (pH <7.05 and base excess <-12), birth asphyxia-related complications (including any of the following conditions: hypoxic ischemic encephalopathy, hypothermia treatment, neonatal seizures, meconium aspiration syndrome or advanced resuscitation after birth) and admission to neonatal intensive care unit (NICU).

RESULTS

Overall rates of umbilical artery acidosis, birth asphyxia-related complications and admission to NICU were 1.08, 0.63 and 6.42%, respectively. Rate of birth asphyxia-related complications gradually increased with duration of second stage: from 0.42% at <1 h to 1.29% at ≥4 h (adjusted RR 2.46 (95% CI 1.66 to 3.66)). For admission to NICU, corresponding rates were 4.97 and 9.45%, and adjusted RR (95% CI) was 1.80 (95% CI 1.58 to 2.04). Compared with duration of pushing <15 min, a duration of pushing ⩾60 min increased rates of acidosis from 0.57 to 1.69% (adjusted RR 2.55 (95% CI 1.51 to 4.30)).

CONCLUSION

Prolonged durations of second stage of labor and pushing are associated with increased RRs of adverse neonatal outcomes. Clinical assessment of fetal well-being is essential when durations of second stage and pushing increases.

Population-based reference curve for umbilical cord arterial pH in infants born at 28 to 42 weeks

OBJECTIVE

The objective of the study was to examine normal variations of umbilical cord arterial pH by gestational age (GA).

STUDY DESIGN

Population-based cohort study of 46 199 infants born from 2008 to 2014 in Stockholm, Sweden, with GA 28 to 42 weeks, Apgar score ⩾7 at 5 min, non-instrumental vaginal delivery, and birth weight for GA⩾3rd and ⩽97th percentile. Quantile regression was used to investigate the associations between GA and infant sex, and pH.

RESULTS

The mean umbilical cord arterial pH (s.d.) was 7.29 (0.10), 7.27 (0.07), 7.25 (0.07) and 7.23 (0.07) among infants born at 28 to 31, 32 to 36, 37 to 41 and 42 weeks, respectively. Arterial pH decreased linearly with increasing GA, and female infants had higher pH than male infants (P<0.001).

CONCLUSION

Umbilical cord arterial pH varied in a linear fashion by GA and was influenced by infant sex. The provided reference curve taking GA into account may yield a more accurate definition of acidosis at birth.

Patients hospitalized abroad as importers of multiresistant bacteria-a cross-sectional study

OBJECTIVES

The pandemic spread of multidrug-resistant (MDR) bacteria poses a threat to healthcare worldwide, with highest prevalence in indigent regions of the (sub)tropics. As hospitalization constitutes a major risk factor for colonization, infection control management in low-prevalence countries urgently needs background data on patients hospitalized abroad.

METHODS

We collected data on 1122 patients who, after hospitalization abroad, were treated at the Helsinki University Hospital between 2010 and 2013. They were screened for methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE), vancomycin-resistant enterococci, carbapenemase-producing Enterobacteriaceae (CPE), multiresistant Pseudomonas aeruginosa and multiresistant Acinetobacter baumannii. Risk factors for colonization were explored by multivariate analysis.

RESULTS

MDR colonization rates were higher for those hospitalized in the (sub)tropics (55%; 208/377) compared with temperate zones (17%; 125/745). For ESBL-PE the percentages were 50% (190/377) versus 12% (92/745), CPE 3.2% (12/377) versus 0.4% (3/745) and MRSA 6.6% (25/377) versus 2.4% (18/745). Colonization rates proved highest in those returning from South Asia (77.6%; 38/49), followed by those having visited Latin America (60%; 9/16), Africa (60%; 15/25) and East and Southeast Asia (52.5%; 94/179). Destination, interhospital transfer, short time interval to hospitalization, young age, surgical intervention, residence abroad, visiting friends and relatives, and antimicrobial use proved independent risk factors for colonization.

CONCLUSIONS

Post-hospitalization colonization rates proved higher in the (sub)tropics than elsewhere; 11% (38/333) of carriers developed an MDR infection. We identified several independent risk factors for contracting MDR bacteria. The data provide a basis for infection control guidelines in low-prevalence countries.

RSDL decontamination of human skin contaminated with the nerve agent VX

Dermal exposure to low volatile organophosphorus compounds (OPC) may lead to penetration through the skin and uptake in the blood circulation. Skin decontamination of toxic OPCs, such as pesticides and chemical warfare nerve agents, might therefore be crucial for mitigating the systemic toxicity following dermal exposure. Reactive skin decontamination lotion (RSDL) has been shown to reduce toxic effects in animals dermally exposed to the nerve agent VX. In the present study, an in vitro flow-through diffusion cell was utilized to evaluate the efficacy of RSDL for decontamination of VX exposed to human epidermis. In particular, the impact of timing in the initiation of decontamination and agent dilution in water was studied. The impact of the lipophilic properties of VX in the RSDL decontamination was additionally addressed by comparing chemical degradation in RSDL and decontamination efficacy between the VX and the hydrophilic OPC triethyl phosphonoacetate (TEPA). The epidermal membrane was exposed to 20, 75 or 90% OPC diluted in deionized water and the decontamination was initiated 5, 10, 30, 60 or 120min post-exposure. Early decontamination of VX with RSDL, initiated 5-10min after skin exposure, was very effective. Delayed decontamination initiated 30-60min post-exposure was less effective but still the amount of penetrated agent was significantly reduced, while further delayed start of decontamination to 120min resulted in very low efficacy. Comparing RSDL decontamination of VX with that of TEPA showed that the decontamination efficacy at high agent concentrations was higher for VX. The degradation mechanism of VX and TEPA during decontamination was dissected by ³¹P NMR spectroscopy of the OPCs following reactions with RSDL and its three nucleophile components. The degradation rate was clearly associated with the high pH of the specific solution investigated; i.e. increased pH resulted in a more rapid degradation. In addition, the solubility of the OPC in RSDL also influenced the degradation rate since the degradation of VX was significantly faster when the NMR analysis was performed in the organic solvent acetonitrile compared to water. In conclusion, we have applied the in vitro flow-through diffusion cell for evaluation of skin decontamination procedures of human epidermis exposed to OPCs. It was demonstrated that early decontamination is crucial for efficient mitigation of epidermal penetration of VX and that almost complete removal of the nerve agent from the skin surface is possible. Our data also indicate that the pH of RSDL together with the solubility of OPC in RSDL are of primary importance for the decontamination efficacy.

Molecular Diffusion in Plasma Membranes of Primary Lymphocytes Measured by Fluorescence Correlation Spectroscopy

Fluorescence correlation spectroscopy (FCS) is a powerful technique for studying the diffusion of molecules within biological membranes with high spatial and temporal resolution. FCS can quantify the molecular concentration and diffusion coefficient of fluorescently labeled molecules in the cell membrane. This technique has the ability to explore the molecular diffusion characteristics of molecules in the plasma membrane of immune cells in steady state (i.e., without processes affecting the result during the actual measurement time). FCS is suitable for studying the diffusion of proteins that are expressed at levels typical for most endogenous proteins. Here, a straightforward and robust method to determine the diffusion rate of cell membrane proteins on primary lymphocytes is demonstrated. An effective way to perform measurements on antibody-stained live cells and commonly occurring observations after acquisition are described. The recent advancements in the development of photo-stable fluorescent dyes can be utilized by conjugating the antibodies of interest to appropriate dyes that do not bleach extensively during the measurements. Additionally, this allows for the detection of slowly diffusing entities, which is a common feature of proteins expressed in cell membranes. The analysis procedure to extract molecular concentration and diffusion parameters from the generated autocorrelation curves is highlighted. In summary, a basic protocol for FCS measurements is provided; it can be followed by immunologists with an understanding of confocal microscopy but with no other previous experience of techniques for measuring dynamic parameters, such as molecular diffusion rates.

Rapid cognitive screening in multiple sclerosis accomplished by the Free Recall and Recognition Test

This study sought to investigate the feasibility of the Free Recall and Recognition Test (FRRT) as a practical screening tool for cognitive impairment in multiple sclerosis (MS). Persons with MS (n =227) were consecutively recruited and assessed with four cognitive tests; FRRT, Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT), and the Mini-Mental State Examination (MMSE). Disease severity was assessed by the Expanded Disability Status Scale (EDSS). The FRRT, which was completed by 99% of the cohort in approximately 5 minutes per assessment, correlated significantly with the other cognitive tests, as well as with the disease severity rating. A cut-off of 4 for the FRRT recall rendered 90% sensitivity and 25% specificity, and a cut-off of 4.2 for the FRRT recognition resulted in 70% sensitivity and 51% specificity. We conclude that the FRRT proved feasible as a practical screening tool for cognitive impairment in MS within a clinical setting. Multiple Sclerosis 2007; 13: 272–274. http://msj.sagepub.com

Forty years of shunt surgery at Rigshospitalet, Denmark: a retrospective study comparing past and present rates and causes of revision and infection

OBJECTIVE

The objective of this study is to review our experience of shunt surgery by investigating 40 years of development in terms of rates of revision and infection, shunt survival and risk factors.

DESIGN AND PARTICIPANTS

Medical records and operative reports were reviewed retrospectively for all patients who underwent primary shunt surgery at our department in the years 2010 to 2012. All results were compared with a previous study from our department. A mixed population consisting of 434 patients was included. Adults (≥15 years) accounted for 89.9% of all patients and the mean follow-up time was 1.71 years.

RESULTS

Overall, 42.6% had a revision of which 65.4% fell within 6 months postoperatively. Low age, high-risk diagnoses and less severe brain injury were associated with a higher risk of revision. One and 5-year shunt survival probabilities were 66.2% (61.5-70.9) and 48.0% (41.1-54.9). Within 4 weeks postoperatively, 3.2% had an infection and overall infection rate was 5.5%. Short duration of surgery and the use of antibiotic prophylaxis were associated with a lower risk of infection. The most frequent causes of revision were valve defects (18.4%) and proximal defects or obstructions (15.7%). Compared to the previous study, no convincing improvement was found with regard to the revision rate (42.6% vs 48.3%, p 0.060) or overall infection rate (5.5% vs 7.4%, p 0.261).

CONCLUSIONS

Regardless of changes in patient demographics, techniques and equipment, risk of revision and infection still constitutes a major challenge in shunt surgery. The absence of convincing improvements calls for more studies concerning strategies to reduce complications.

A policy of routine umbilical cord blood gas analysis decreased missing samples from high-risk births

AIM

This study compared obstetric units practicing routine or selective umbilical cord blood gas analysis, with respect to the risk of missing samples in high-risk deliveries and in infants with birth asphyxia.

METHODS

This was a Swedish population-based cohort study that used register data for 155 235 deliveries of live singleton infants between 2008 and 2014. Risk ratios and 95% confidence intervals were calculated to estimate the association between routine and selective umbilical cord blood gas sampling strategies and the risk of missing samples.

RESULTS

Selective sampling increased the risk ratios when routine sampling was used as the reference, with a value of 1.0, and these were significant in high-risk deliveries and birth asphyxia. The risk ratios for selective sampling were large-for-gestational age (9.07), preterm delivery at up to 36 weeks of gestation (8.24), small-for-gestational age (7.94), two or more foetal scalp blood samples (5.96), an Apgar score of less than seven at one minute (2.36), emergency Caesarean section (1.67) and instrumental vaginal delivery (1.24).

CONCLUSION

Compared with routine sampling, selective umbilical cord blood gas sampling significantly increased the risks of missing samples in high-risk deliveries and in infants with birth asphyxia.

IL-15, TIM-3 and NK cells subsets predict responsiveness to anti-CTLA-4 treatment in melanoma patients

Despite the success of immune checkpoint blockade in melanoma, the majority of patients do not respond. We hypothesized that the T and NK cell subset frequencies and expression levels of their receptors may predict responses and clinical outcome of anti-CTLA-4 treatment. We thus characterized the NK and T cell phenotype, as well as serum levels of several cytokines in 67 melanoma patients recruited in Italy and Sweden, using samples drawn prior to and during treatment. Survival correlated with low expression of the inhibitory receptor TIM-3 on circulating T and NK cells prior to and during treatment and with the increased frequency of mature circulating NK cells (defined as CD3^-CD56^dim CD16⁺) during treatment. Survival also correlated with low levels of IL-15 in the serum. Functional experiments in vitro demonstrated that sustained exposure to IL-15 enhanced the expression of PD-1 and TIM-3 on both T and NK cells, indicating a causative link between high IL-15 levels and enhanced expression of TIM-3 on these cells. Receptor blockade of TIM-3 improved NK cell-mediated elimination of melanoma metastasis cell lines in vitro. These observations may lead to the development of novel biomarkers to predict patient response to checkpoint blockade treatment. They also suggest that induction of additional checkpoints is a possibility that needs to be considered when treating melanoma patients with IL-15.

B vitamin treatments modify the risk of myocardial infarction associated with a MTHFD1 polymorphism in patients with stable angina pectoris

BACKGROUND

Methylenetetrahydrofolate dehydrogenase (MTHFD1) catalyzes three sequential reactions that metabolize derivatives of tetrahydrofolate (THF) in folate-dependent one-carbon metabolism. Impaired MTHFD1 flux has been linked to disturbed lipid metabolism and oxidative stress. However, limited information is available on its relation to the development of atherothrombotic cardiovascular disease.

METHODS AND RESULTS

We explored the association between a MTHFD1 polymorphism (rs1076991 C > T) and acute myocardial infarction (AMI), and potential effect modifications by folic acid/B12 and/or vitamin B6 treatment in suspected stable angina pectoris patients (n = 2381) participating in the randomized Western Norway B Vitamin Intervention Trial (WENBIT). During the median follow-up of 4.9 years 204 participants (8.6%) suffered an AMI. After adjusting for established CVD risk factors, the MTHFD1 polymorphism was significantly associated with AMI (HR: 1.49; 95% CI, 1.23-1.81). A similar association was observed among patients allocated to treatment with vitamin B6 alone (HR: 1.53; 95% CI, 1.01-2.31), and an even stronger relationship was seen in patients treated with both vitamin B6 and folic acid/B12 (HR: 2.35; 95% CI, 1.55-3.57). However, no risk association between the MTHFD1 polymorphism and AMI was seen in patients treated with placebo (HR: 1.29; 95% CI, 0.86-1.93) or folic acid/B12 (1.17; 95% CI, 0.83-1.65).

CONCLUSION

A common and functional MTHFD1 polymorphism is associated with increased risk of AMI, although the risk seems to be dependent on specific B vitamin treatment. Further studies are warranted to elucidate the possible mechanisms, also in order to explore potential effect modifications by nutritional factors.

Individual Face-to-Face Cognitive Behavioural Therapy in Multiple Sclerosis: A Qualitative Study

OBJECTIVE

To investigate how people with multiple sclerosis (MS) experience their participation in individual, face-to-face cognitive behavioural therapy (CBT) aimed at alleviating depressive symptoms.

METHOD

Semistructured interviews with 12 participants were conducted after CBT and analyzed using qualitative content analysis.

RESULTS

Two main themes emerged: CBT as a demanding process and confronting everyday life after CBT with self-knowledge and well-being. The participants had gained strategies for handling feelings of depression and anxiety. The therapist was considered important for guiding them through the demanding therapy.

CONCLUSION

It is important to inform the participants of what CBT entails so that they are mentally prepared for the demanding process and can make the necessary adjustments in their daily life. Knowledge of MS among the therapists as well as collaboration with the multidisciplinary MS care may facilitate participation in CBT.

Cytokines Induce Faster Membrane Diffusion of MHC Class I and the Ly49A Receptor in a Subpopulation of Natural Killer Cells

Cytokines have the potential to drastically augment immune cell activity. Apart from altering the expression of a multitude of proteins, cytokines also affect immune cell dynamics. However, how cytokines affect the molecular dynamics within the cell membrane of immune cells has not been addressed previously. Molecular movement is a vital component of all biological processes, and the rate of motion is, thus, an inherent determining factor for the pace of such processes. Natural killer (NK) cells are cytotoxic lymphocytes, which belong to the innate immune system. By fluorescence correlation spectroscopy, we investigated the influence of cytokine stimulation on the membrane density and molecular dynamics of the inhibitory receptor Ly49A and its ligand, the major histocompatibility complex class I allele H-2D^d, in freshly isolated murine NK cells. H-2D^d was densely expressed and diffused slowly in resting NK cells. Ly49A was expressed at a lower density and diffused faster. The diffusion rate in resting cells was not altered by disrupting the actin cytoskeleton. A short-term stimulation with interleukin-2 or interferon-α + β did not change the surface density of moving H-2D^d or Ly49A, despite a slight upregulation at the cellular level of H-2D^d by interferon-α + β, and of Ly49A by IL-2. However, the molecular diffusion rates of both H-2D^d and Ly49A increased significantly. A multivariate analysis revealed that the increased diffusion was especially marked in a subpopulation of NK cells, where the diffusion rate was increased around fourfold compared to resting NK cells. After IL-2 stimulation, this subpopulation of NK cells also displayed lower density of Ly49A and higher brightness per entity, indicating that Ly49A may homo-cluster to a larger extent in these cells. A faster diffusion of inhibitory receptors could enable a faster accumulation of these molecules at the immune synapse with a target cell, eventually leading to a more efficient NK cell response. It has previously been assumed that cytokines regulate immune cells primarily via alterations of protein expression levels or posttranslational modifications. These findings suggest that cytokines may also modulate immune cell efficiency by increasing the molecular dynamics early on in the response.

Exposure to acid-suppressing drugs during pregnancy and the risk of asthma in childhood: an observational cohort study

BACKGROUND

Some research has suggested a potential link between prenatal exposure to proton pump inhibitors (PPIs) or H2 -receptor antagonists (H2 RAs) and the development of childhood asthma.

AIM

To quantify the relative risk of asthma in children who experienced pre-natal exposure to PPIs and/or H2 RAs, adjusting for potential confounders.

METHODS

In this observational cohort study (NCT01787435), women aged 18-45 years with completed pregnancies between January 1996 and December 2010 were identified from The Health Improvement Network in the United Kingdom, and were linked to infants. Hazard ratios (HRs) were estimated using Cox proportional hazard models.

RESULTS

Our analysis identified 2371 prenatally exposed and 7745 unexposed infants. The incidence of asthma (per 1000 person-years) was 19.52 in the unexposed cohort, 23.88 in the PPI cohort and 32.16 in the H2 RA cohort. After adjusting for maternal healthcare utilisation during the year before pregnancy, the HR for asthma in infants whose mothers received prescriptions at any time during pregnancy was 1.12 (95% confidence interval: 0.88-1.44) for PPIs and 1.43 (1.20-1.70) for H2 RAs, when compared with unexposed infants. With further adjustment for maternal comorbidities and other medications, the HR for asthma was 1.03 (0.76-1.40) for PPIs and 1.32 (1.05-1.64) for H2 RAs.

CONCLUSIONS

Our analysis showed no association between prenatal exposure to PPIs and asthma in childhood after adjusting for confounders. The association found for H2 RAs may be explained largely by underlying environmental or genetic factors, as suggested by reductions in hazard ratio estimates following adjustment for maternal comorbidities.

High respiratory rate is associated with early reduction of lung edema clearance in an experimental model of ARDS

BACKGROUND

The independent impact of respiratory rate on ventilator-induced lung injury has not been fully elucidated. The aim of this study was to investigate the effects of two clinically relevant respiratory rates on early ventilator-induced lung injury evolution and lung edema during the protective ARDSNet strategy. We hypothesized that the use of a higher respiratory rate during a protective ARDSNet ventilation strategy increases lung inflammation and, in addition, lung edema associated to strain-induced activation of transforming growth factor beta (TGF-β) in the lung epithelium.

METHODS

Twelve healthy piglets were submitted to a two-hit lung injury model and randomized into two groups: LRR (20 breaths/min) and HRR (40 breaths/min). They were mechanically ventilated during 6 h according to the ARDSNet strategy. We assessed respiratory mechanics, hemodynamics, and extravascular lung water (EVLW). At the end of the experiment, the lungs were excised and wet/dry ratio, TGF-β pathway markers, regional histology, and cytokines were evaluated.

RESULTS

No differences in oxygenation, PaCO2 levels, systemic and pulmonary arterial pressures were observed during the study. Respiratory system compliance and mean airway pressure were lower in LRR group. A decrease in EVLW over time occurred only in the LRR group (P < 0.05). Wet/dry ratio was higher in the HRR group (P < 0.05), as well as TGF-β pathway activation. Histological findings suggestive of inflammation and inflammatory tissue cytokines were higher in LRR.

CONCLUSION

HRR was associated with more pulmonary edema and higher activation of the TGF-β pathway. In contrast with our hypothesis, HRR was associated with less lung inflammation.

[Fast identification of febrile neutropenia improves the outcome]

The purpose of this article is to describe the management of febrile neutropenia in the medical emergency room. Symptoms and signs of inflammation in patients receiving chemotherapy may be blunted or absent and fever may be the only sign of severe infection. Early initiation of empirical antibiotics is essential for the outcome. A beta-lactam antibiotic is the treatment of choice and the regimen should be re-evaluated frequently in absence of clinical improvement. The treating oncologist should always be involved for advice and for assuring adjustments in future chemotherapy.

Depletion of IL-2 receptor β-positive cells protects from diabetes in non-obese diabetic mice

The destruction of β-cells in type 1 diabetes (T1D) progresses silently until only a minor fraction of the β-cells remain. A late acting therapy leading to the prevention of further β-cell killing would therefore be desirable. CD122, the β chain of the interleukin-2 receptor, is highly expressed on natural killer (NK) cells and on a subpopulation of CD8 T cells. In this study, we have treated non-obese diabetic (NOD) mice with a depleting antibody against CD122. The treatment protected from diabetes, even when initiated just before disease onset. The degree of leukocyte infiltration into islets was unaffected by the treatment, further supporting effectiveness late in the disease process. It effectively removed all NK cells from the spleen, pancreas and pancreatic lymph nodes and abolished NK cell activity. Interestingly, despite the lack of CD122 expression on CD8 T cells in the pancreas, the overall frequency of CD8 cells decreased in this organ, whereas it was unaffected in the spleen. T cells were also still capable to respond against a foreign antigen. Conclusively, targeting of CD122(+) cells could represent a novel treatment strategy against T1D.

Health-related quality of life in partners of persons with MS: a longitudinal 10-year perspective

OBJECTIVES

Multiple sclerosis (MS) impacts the health-related quality of life (HRQL) in partners, but knowledge on the longitudinal perspective is needed. The aim was to analyse HRQL in partners of persons with MS living in Sweden a decade ago and after 10 years.

MATERIALS AND METHODS

Partners were identified through a population-based study of persons with MS in Stockholm. Information on HRQL (the Sickness Impact profile), personal factors and disease-specific factors, and measures of functioning of persons with MS was collected at both time points mainly by home visits.

RESULTS

Some 64 of 102 identified partners (63%) agreed to participate at baseline, and at 10 years 40 of 54 eligible partners were included (74%). HRQL in partners was worse than in a Swedish, aged-grouped reference population at both baseline and follow-up. Depressive symptoms in persons with MS were independently associated with worse HRQL in partners.

CONCLUSIONS

Depressive symptoms in persons with MS were associated with worse HRQL in their partners, and HRQL of partners was continuously impacted in the longitudinal perspective. This knowledge needs to be accounted for in the planning of MS care, together with the development of evidence-based support for depressive symptoms, and engagement in recreational life in both partners and persons with MS.

Incidence rates and trends of hip/femur fractures in five European countries: comparison using e-healthcare records databases

Hip fractures represent a major public health challenge worldwide. Multinational studies using a common methodology are scarce. We aimed to estimate the incidence rates (IRs) and trends of hip/femur fractures over the period 2003-2009 in five European countries. The study was performed using seven electronic health-care records databases (DBs) from Denmark, The Netherlands, Germany, Spain, and the United Kingdom, based on the same protocol. Yearly IRs of hip/femur fractures were calculated for the general population and for those aged ≥50 years. Trends over time were evaluated using linear regression analysis for both crude and standardized IRs. Sex- and age-standardized IRs for the UK, Netherlands, and Spanish DBs varied from 9 to 11 per 10,000 person-years for the general population and from 22 to 26 for those ≥50 years old; the German DB showed slightly higher IRs (about 13 and 30, respectively), whereas the Danish DB yielded IRs twofold higher (19 and 52, respectively). IRs increased exponentially with age in both sexes. The ratio of females to males was ≥2 for patients aged ≥70-79 years in most DBs. Statistically significant trends over time were only shown for the UK DB (CPRD) (+0.7% per year, P < 0.01) and the Danish DB (-1.4% per year, P < 0.01). IRs of hip/femur fractures varied greatly across European countries. With the exception of Denmark, no decreasing trend was observed over the study period.

Differences in exosome populations in human breast milk in relation to allergic sensitization and lifestyle

BACKGROUND

Breast-feeding has many beneficial effects on the developing immune system of the newborn. Breast milk contains immunoregulatory factors, such as nano-sized vesicles named exosomes. This study aimed at characterizing breast milk exosomes from human early milk and mature milk and to investigate whether allergic sensitization and an anthroposophic lifestyle could influence the exosome profile.

METHODS

Breast milk was collected from 22 mothers at day 3-8 and from 61 mothers at 2 months postpartum, all part of the ALADDIN birth cohort. Isolated exosomes were captured on anti-MHC-class II- or anti-CD63 beads and analyzed by flow cytometry. Exosomal phenotype was related to lifestyle and allergic sensitization of the mothers, and sensitization of the child at 2 years of age.

RESULTS

We found a higher content of exosomes in early milk compared with mature milk. Early milk exosomes were enriched in HLA-DR molecules and displayed significantly lower levels of HLA-ABC compared with those in mature milk. Phenotypically different subpopulations of exosomes were found in mature milk. Significantly lower levels of MUC1 were detected on CD63-enriched exosomes from sensitized mothers compared with nonsensitized. Furthermore, women with an anthroposophic lifestyle had significantly lower MUC1 expression on their HLA-DR-enriched milk exosomes and up-regulated levels of CD63 on CD63-enriched exosomes compared with nonanthroposophic mothers. Notably, mothers whose children developed sensitization had an increased amount of HLA-ABC on their milk exosomes enriched for CD63.

CONCLUSIONS

The phenotype of exosomes in breast milk varies with maternal sensitization and lifestyle, which might influence allergy development in the child.

Peripheral and site-specific CD4(+) CD28(null) T cells from rheumatoid arthritis patients show distinct characteristics

Proinflammatory CD4(+) CD28(null) T cells are frequently found in the circulation of patients with rheumatoid arthritis (RA), but are less common in the rheumatic joint. In the present study, we sought to identify functional differences between CD4(+) CD28(null) T cells from blood and synovial fluid in comparison with conventional CD28-expressing CD4(+) T cells. Forty-four patients with RA, displaying a distinct CD4(+) CD28(null) T cell population in blood, were recruited for this study; the methylation status of the IFNG locus was examined in isolated T cell subsets, and intracellular cytokine production (IFN-γ, TNF, IL-17) and chemokine receptor expression (CXCR3, CCR6 and CCR7) were assessed by flow cytometry on T cells from the two compartments. Circulating CD4(+) CD28(null) T cells were significantly more hypomethylated in the CNS-1 region of the IFNG locus than conventional CD4(+) CD28(+) T cells and produced higher levels of both IFN-γ and TNF after TCR cross-linking. CD4(+) CD28(null) T cells from the site of inflammation expressed significantly more CXCR3 and CCR6 compared to their counterparts in blood. While IL-17A production could hardly be detected in CD4(+) CD28(null) cells from the blood, a significant production was observed in CD4(+) CD28(null) T cells from synovial fluid. CD4(+) CD28(null) T cells were not only found to differ from conventional CD4(+) CD28(+) T cells in the circulation, but we could also demonstrate that synovial CD4(+) CD28(null) T cells showed additional effector functions (IL-17 coproduction) as compared to the same subset in peripheral blood, suggesting an active role for these cells in the perpetuation of inflammation in the subset of patients having a CD28(null) population.

Transient state microscopy probes patterns of altered oxygen consumption in cancer cells

Altered cellular metabolism plays an important role in many diseases, not least in many forms of cancer, where cellular metabolic pathways requiring lower oxygen consumption are often favored (the so-called Warburg effect). In this work, we have applied fluorescence-based transient state imaging and have exploited the environment sensitivity of long-lived dark states of fluorophores, in particular triplet state decay rates, to image the oxygen consumption of living cells. Our measurements can resolve differences in oxygen concentrations between different regions of individual cells, between different cell types, and also based on what metabolic pathways the cells use. In MCF-7 breast cancer cells, higher oxygen consumption can be detected when they rely on glutamine instead of glucose as their main metabolite, predominantly undergoing oxidative phosphorylation rather than glycolysis. By use of the high triplet yield dye Eosin Y the irradiance requirements during the measurements can be kept low. This reduces the instrumentation requirements, and harmful biological effects from high excitation doses can be avoided. Taken together, our imaging approach is widely applicable and capable of detecting subtle changes in oxygen consumption in live cells, stemming from the Warburg effect or reflecting other differences in the cellular metabolism. This may lead to new diagnostic means as well as advance our understanding of the interplay between cellular metabolism and major disease categories, such as cancer.