Using a Fluid Resuscitation Algorithm to Reduce the Incidence of Abdominal Compartment Syndrome in the Burn Intensive Care Unit

BACKGROUND

Patients with large burns must be carefully resuscitated to balance adequate tissue perfusion with the risk of end-organ damage. One devastating complication of overresuscitation is abdominal compartment syndrome. Reducing the volume of fluids given during resuscitation may reduce the incidence of abdominal compartment syndrome and improve outcomes.

OBJECTIVE

To determine whether decreasing fluid resuscitation volume in a burn center reduced the incidence of abdominal compartment syndrome.

METHODS

This retrospective cohort study involved all patients with severe burns (total body surface area ≥20%) who were admitted to a burn intensive care unit over 4 years (n = 166). Primary outcomes were required fluid volume, whether differences in the patient characteristics measured affected outcomes, rate of abdominal compartment syndrome, and incidence of abdominal hypertension. After the first 2 years, the Parkland fluid resuscitation algorithm was modified to decrease the volume goal, and patients were assessed for the incidence of abdominal compartment syndrome and related complications such as kidney failure, abdominal hypertension, and ventilator days.

RESULTS

A total of 16% of patients resuscitated using the Parkland equation experienced abdominal compartment syndrome compared with 10% of patients resuscitated using the modified algorithm, a difference of 6 percentage points (P = .39). Average volume administered was 11.8 L using the Parkland formula and 9.4 L using the modified algorithm (P = .03).

CONCLUSION

Despite a significant decrease in the amount of fluid administered, no significant difference was found in incidence of abdominal compartment syndrome or urine output. Matched prospective studies are needed to improve resuscitation care for patients with large burns.

[Salivary gland ultrasound or biopsy? : Comparison of methods based on case examples]

BACKGROUND

Ultrasound examination of the salivary glands (SG) is a quick and noninvasive method to detect and semiquantitatively estimate typical changes in the large SG in Sjögren's syndrome (SS). The differential diagnosis of SS is difficult because several diseases and adverse effects of treatment have a similar clinical picture as SS with sicca syndrome and can even induce alterations in the SG (mimic diseases). Hence, for a long time an SG biopsy was regarded as the diagnostic procedure of choice, especially in SS‑A negative patients, whereas the significance of SD sonography is still controversially discussed.

OBJECTIVE

Comparison of typical and atypical changes for SS in the salivary glands in ultrasound and associated histological sections.

MATERIAL AND METHODS

This article describes six patient cases with antibody positive or negative SS with and without typical SS ultrasound patterns, SS-associated lymphoma, sarcoidosis and IgG4-associated disease. The findings of the sonographic examination of the parotid glands and the associated histology of the SD are explained and put into context.

RESULTS

The SSA antibody positive patients with SS show a typical sonographic pattern with hypoechoic foci, especially if the disease has been present for a long time. This pattern can help support the diagnosis of SS. The ultrasound patterns of the mimic diseases sometimes differ significantly from the typical patterns of pSS. The histological examination of the SG helps to corroborate the diagnosis but low histological focus scores, in particular, require a critical synopsis of the clinical, serological and imaging findings.

CONCLUSION

Both salivary gland ultrasound and the histological examination of SG biopsies are justified in the diagnostics and differential diagnosis of SS and sicca syndrome.

Wild and weedy Hesperis matronalis hosts turnip mosaic virus across heterogeneous landscapes in upstate New York

Turnip mosaic virus (TuMV) is a widespread and economically important pathogen in agricultural crops and has the widest known host range in the virus family Potyviridae. While management of the virus and its aphid vectors in agricultural fields decreases virus incidence, many alternative wild hosts for TuMV may serve as source populations for crop infection through spillover. Over thirty years ago, research demonstrated that the introduced brassica, Dame's Rocket (Hesperis matronalis) hosts several viruses, including TuMV. Here, we use both enzyme-linked immunosorbent assays (ELISA) and next generation sequencing to document the frequent infection by TuMV of Dame's Rocket, which is common and widespread in disturbed areas around crop fields in upstate New York. Deep sequencing of multiple tissue types of symptomatic hosts indicate that the infection is systemic and causes diagnostic, visible symptoms. In a common garden experiment using host populations from across upstate New York, we found evidence for genetic tolerance to TuMV infection in H. matronalis. Field surveys show that TuMV prevalence varies across populations, but is generally higher in agricultural areas. Examining disease dynamics in this and other common alternative hosts will enhance our understanding of TuMV epidemiology and, more broadly, virus distribution in wild plants.

Glioblastoma extracellular vesicles influence glial cell hyaluronic acid deposition to promote invasiveness

Background

Infiltration of glioblastoma (GBM) throughout the brain leads to its inevitable recurrence following standard-of-care treatments, such as surgical resection, chemo-, and radiotherapy. A deeper understanding of the mechanisms invoked by GBM to infiltrate the brain is needed to develop approaches to contain the disease and reduce recurrence. The aim of this study was to discover mechanisms through which extracellular vesicles (EVs) released by GBM influence the brain microenvironment to facilitate infiltration, and to determine how altered extracellular matrix (ECM) deposition by glial cells might contribute to this.

Methods

CRISPR was used to delete genes, previously established to drive carcinoma invasiveness and EV production, from patient-derived primary and GBM cell lines. We purified and characterized EVs released by these cells, assessed their capacity to foster pro-migratory microenvironments in mouse brain slices, and evaluated the contribution made by astrocyte-derived ECM to this. Finally, we determined how CRISPR-mediated deletion of genes, which we had found to control EV-mediated communication between GBM cells and astrocytes, influenced GBM infiltration when orthotopically injected into CD1-nude mice.

Results

GBM cells expressing a p53 mutant (p53R273H) with established pro-invasive gain-of-function release EVs containing a sialomucin, podocalyxin (PODXL), which encourages astrocytes to deposit ECM with increased levels of hyaluronic acid (HA). This HA-rich ECM, in turn, promotes migration of GBM cells. Consistently, CRISPR-mediated deletion of PODXL opposes infiltration of GBM in vivo.

Conclusions

This work describes several key components of an EV-mediated mechanism though which GBM cells educate astrocytes to support infiltration of the surrounding healthy brain tissue.

POS0774 ANTI-Sm AUTOANTIBODIES IDENTIFY A PHENOTYPE OF SEVERE SLE WITH AN ASSOCIATED SERUM BIOMARKER PROFILE

Background

Antibodies to Smith (Sm) have been described as one of the most specific autoantibodies for systemic lupus erythematosus (SLE). Other than its association with lupus nephritis, there is, however, limited understanding of its clinical significance1,2.

Objectives

To describe clinical associations and serum protein profiles of anti-Sm positivity in SLE.

Methods

Patients fulfilling SLE classification criteria who were followed longitudinally in a prospective multicentre cohort were studied according to their baseline anti-Sm antibody status. Comparison between Sm+ and Sm- patients was made using descriptive statistics. Clinical associations of Sm positivity with patient disease characteristics were studied using logistic regression. In a subset, 211 serum analytes were measured using Quantibody, Luminex and ELISA assays. Associations between serum proteins and Sm positivity were studied using Least Absolute Shrinkage and Selection Operator (LASSO) penalised regression, adjusting for demographics (age, sex, ethnicity) and medication use

Results

383 patients were studied with median (IQR) follow-up of 4.9 (2,9) years; 65 (17%) had positive anti-Sm antibodies. Sm+ patients were significantly more likely to be of non-European ancestry (OR 2.73, 95% CI 1.55-4.82, p<0.001), and to be positive for anti-dsDNA antibodies (OR 2.8, 95% CI 2.3-3.4, p<0.001), anti-RNP antibodies (OR 15.7, 95% CI 13.9-17.8, p<0.001), direct anti-globulin test (OR 2.36, 95% CI 2.07-2.7, p<0.001) and hypocomplementemia (OR 7.73, 95% CI 5.1-11.7, p<0.001). Sm+ patients were significantly more likely to have active disease during the observation period in a range of organ domains, including mucocutaneous, renal, vasculitis and fever.

More Sm+ patients had episodes of High Disease Activity Status (HDAS, SLEDAI-2K ≧10)3 (OR 3.07, 95% CI 1.70-5.54, p<0.001) and persistent active disease (time-adjusted mean SLEDAI-2K > 4) (OR 3.23. 95% CI 1.84-5.70, p<0.001). Conversely, fewer Sm+ patients attained LLDAS for ≥50% observed time (19.7% vs 41.8%, p=0.002). Sm+ patients were more likely to be treated with glucocorticoids, immunosuppressants, and rituximab. There was no significant difference in damage accrual between Sm + and Sm - patients.

In serum protein analysis (n=197, 29 Sm+), LASSO modelling retained 3 proteins associated with Sm+ status, CXCL13, IL1RL1 and FLT1, along with Asian ethnicity and age. In analysis including pairwise interaction between predictors, 28 Sm+ associated proteins were identified, including CCL4, VCAM1, IL1RL1, Fcg R IIB/C, TDGF1, CEACAM1, TIMP1, BMP5, GDF15, and TNFRSF17.

Conclusion

Anti-Sm autoantibodies, present in 17% of SLE patients, were strongly associated with classical disease manifestations, more severe disease activity, and a specific serological and proteomic profile. These findings suggest anti-Sm+ SLE as a specific disease subset.

References

[1]Barada, FA., B.S. Andrews, J.S. Davis, R.P. Taylor, Antibodies to Sm in patients with systemic lupus erythematosus. Correlation of Sm antibody titers with disease activity and other laboratory parameters. Arthritis Rheum, 1981. 24:1236-1244

[2]Arroyo-Avilla, M, Y. Santiago-Casas, G.McGwin, R.S. Cantor, M. Petri, R. Ramsey-Goldman, J.D. Reveille, R.P.Kimberly, G.S. Alarcon, L.M.Vila, E.E. Brown. Clinical Associations of anti-Smith antibodies in PROFILE: a multi-ethnic lupus cohort. 2015. 34:1217-1223

[3]Koelmeyer, R., H.T. Nim, M. Nikpour, Y.B. Sun, A. Kao, O. Guenther, E. Morand, and A. Hoi, High disease activity status suggests more severe disease and damage accrual in systemic lupus erythematosus. Lupus Sci Med, 2020. 7(1).

Acknowledgements

I would like to acknowledge participants and clinicians involved with the Australian Lupus Registry & Biobank

Disclosure of Interests

None declared

The WHO 2016 diagnostic criteria for Acute Myeloid leukemia with myelodysplasia related changes (AML-MRC) produce a very heterogeneous entity: A retrospective analysis of the FAB subtype RAEB-T

We studied 79 patients with AML-MRC or RAEB-T, who were later reclassified according to the WHO classification. Marrow slides were examined cytomorphologically with regard to dysplasia. Patients were followed up until March 2020. Thirty-one patients underwent allogeneic stem cell transplantation (median survival (ms) 16 months), 14 were treated with induction chemotherapy (ms 8.4 months), 18 received hypomethylating agents (ms 9.2 months), 16 received low dose chemotherapy or best supportive care (ms 2.4 months). Only 30.4 % fulfilled the morphologic WHO criteria. 46.8 % were classified as AML-MRC by an antecedent MDS, 54.4 % of the pts were classified by MDS-related chromosomal abnormalities. 5 % did not fulfill any of the criteria and were entered based on 20-29 % medullary blasts. There was no difference in ms between pts presenting with > 50 % dysplasia as compared to pts with dysplasia between 10 % and 50 % (ms 9.1 vs 9.9 months, p = n.s.) or for pts with antecedent MDS (ms 9.1 vs 8.9 months, p = n.s.). Myelodysplasia-related cytogenetic abnormalities were associated with a worse outcome (ms 8.1 vs 13.5 months, p = 0.026). AML-MRC in its current definition is a heterogenous entity. Dysplasia of ≥ 50 % in ≥ two lineages is not helpful for diagnostics and prognostication and therefore should be deleted in future classifications. We recommend utilizing the WHO guidelines for defining dysplasia (10 % or greater in ≥ 1 of the three myeloid cell lines) assisting in establishing the diagnosis of MDS.

Heterogeneous Microscopic Dynamics of Intruded Water in a Superhydrophobic Nanoconfinement: Neutron Scattering and Molecular Modeling

With their strong confining porosity and versatile surface chemistry, zeolitic imidazolate frameworks-including the prototypical ZIF-8-display exceptional properties for various applications. In particular, the forced intrusion of water at high pressure (∼25 MPa) into ZIF-8 nanopores is of interest for energy storage. Such a system reveals also ideal to study experimentally water dynamics and thermodynamics in an ultrahydrophobic confinement. Here, we report on neutron scattering experiments to probe the molecular dynamics of water within ZIF-8 nanopores under high pressure up to 38 MPa. In addition to an overall confinement-induced slowing down, we provide evidence for strong dynamical heterogeneities with different underlying molecular dynamics. Using complementary molecular simulations, these heterogeneities are found to correspond to different microscopic mechanisms inherent to vicinal molecules located in strongly adsorbing sites (ligands) and other molecules nanoconfined in the cavity center. These findings unveil a complex microscopic dynamics, which results from the combination of surface residence times and exchanges between the cavity surface and center.

The Impact of Race/Ethnicity on the Outcomes of Burn Patients: A Systematic Review of the Literature

Racial and ethnic disparities are endemic to the United States and are only beginning to attract the attention of researchers. With an increasingly diverse population, focused and tailored medicine to provide more equitable care is needed. For surgical trauma populations, this topic is a small but expanding field and still rarely mentioned in burn medicine. Disparities in prevention, treatment, and recovery outcomes between different racial and ethnic minorities who are burned are rarely discussed. The purpose of this study is to determine the current status of identified disparities of care in the burn population literature and areas of future research. A systematic review was conducted of literature utilizing PubMed for articles published between 2000-2020. Searches were used to identify articles that crossed the burn term (burn patient OR burn recovery OR burn survivor OR burn care) and a race/ethnicity and insurance status-related term (race/ethnicity OR African-American OR Black OR Asian OR Hispanic OR Latino OR Native American OR Indigenous OR Mixed race OR 2 or more races OR socioeconomic status OR insurance status). Inclusion criteria were English studies in the US that discussed disparities in burn injury outcomes or risk factors associated with race/ethnicity. 1,169 papers were populated, 55 were reviewed, and 36 articles met inclusion criteria. Most studies showed minorities had poorer inpatient and outpatient outcomes. While this is a concerning trend, there is a paucity of literature in this field and more research is needed to create culturally-tailored medical care and address the needs of disadvantaged burn survivors.

Attenuated Directed Exploration during Reinforcement Learning in Gambling Disorder

Gambling disorder (GD) is a behavioral addiction associated with impairments in value-based decision-making and behavioral flexibility and might be linked to changes in the dopamine system. Maximizing long-term rewards requires a flexible trade-off between the exploitation of known options and the exploration of novel options for information gain. This exploration-exploitation trade-off is thought to depend on dopamine neurotransmission. We hypothesized that human gamblers would show a reduction in directed (uncertainty-based) exploration, accompanied by changes in brain activity in a fronto-parietal exploration-related network. Twenty-three frequent, non-treatment seeking gamblers and twenty-three healthy matched controls (all male) performed a four-armed bandit task during functional magnetic resonance imaging (fMRI). Computational modeling using hierarchical Bayesian parameter estimation revealed signatures of directed exploration, random exploration, and perseveration in both groups. Gamblers showed a reduction in directed exploration, whereas random exploration and perseveration were similar between groups. Neuroimaging revealed no evidence for group differences in neural representations of basic task variables (expected value, prediction errors). Our hypothesis of reduced frontal pole (FP) recruitment in gamblers was not supported. Exploratory analyses showed that during directed exploration, gamblers showed reduced parietal cortex and substantia-nigra/ventral-tegmental-area activity. Cross-validated classification analyses revealed that connectivity in an exploration-related network was predictive of group status, suggesting that connectivity patterns might be more predictive of problem gambling than univariate effects. Findings reveal specific reductions of strategic exploration in gamblers that might be linked to altered processing in a fronto-parietal network and/or changes in dopamine neurotransmission implicated in GD.SIGNIFICANCE STATEMENT Wiehler et al. (2021) report that gamblers rely less on the strategic exploration of unknown, but potentially better rewards during reward learning. This is reflected in a related network of brain activity. Parameters of this network can be used to predict the presence of problem gambling behavior in participants.

Clinical Experience with Icodextrin in Continuous Ambulatory Peritoneal Dialysis Patients

Objectives

To review the clinical experience in the United Kingdom with icodextrin (Ic).

Design

A retrospective multicenter study.

Patients

(1) the MICAS 1 patients who received Ic and elected to continue using it (called MICAS 2 patients), and (2) patients started on Ic on a named-patient basis (called compassionate use patients). Nearly all this latter group had ultrafiltration (UF) failure and were approaching hemodialysis (HC).

Interventions

The institution of one Ic bag, as the overnight exchange, usually in addition to three glucose bags.

Results

(1) MICAS 2: Of the 67 patients who received Ic and completed MICAS 1, 48 (72%) patients from eight units in the United Kingdom wished to continue Ic. Forty two percent of MICAS 2 patients were well on Ic after approximately 30 months of study (including the 6 months on MICAS 1). The main reasons for withdrawal were transplantation (21 %), death (17%), or transfer to HC for reasons other than UF failure (10%). There were no significant changes in laboratory data, including hematology, simple biochemistry, bone biochemistry, liver function tests, serum osmolality, and maltose levels. The adverse events reported were incidental to Ic. (2) Compassionate use: 30/63 (48%) patients remain well on Ic after 10 months of study. Eight patients (12%) went on to experience UF failure (again) after 13 months on Ic, requiring transfer to HC. The other main outcomes were death (11 %), transplantation (11 %), or transfer to HC for reasons unrelated to Ic (16%), usually intractable peritonitis. The serum sodium concentration decreased from 136.6±3.8 to 134.4±4.2 mmol/L (p < 0.05). There were no other significant changes in hematology or biochemistry measurements.

Conclusion

In MICAS 2 Ic probably maintained its effects, since there were no withdrawals due to UF failure. The compassionate use program has shown that a single Ic exchange is useful in UF failure, being able to prevent or delay transfer to hemodialysis. In both studies the safety and efficacy of Ic has been demonstrated in a large group of patients. A total of 192 patient-years of experience (including MICAS 1) has been accumulated to date. Properly controlled studies are needed to determine whether Ic, in its present form, should remain a “special needs” product (for UF failure) or whether it could replace glucose as the treatment of choice for CAPC patients.

A United Kingdom Multicenter Study of Icodextrin in Continuous Ambulatory Peritoneal Dialysis

While glucose remains the only osmotic agent used universally for peritoneal dialysis, its various shortcomings for the long dwell equilibration continuous ambulatory peritoneal dialysis (CAPD) has led to a search for alternative agents. The large molecular weight group has been of interest, because these agents theoretically would lead to greater ultrafiltration and a better metabolic profile. Mostsubstances (dextrans, charged macromolecules) have been found unsuitable for reasons of insolubility, allergenicity, and peritoneal toxicity. Short-chain polypeptides have been studied in humans, but the experience is limited, and there is the potential for allergenicity with long-term use.

The only large molecular weight agent that has been studied in some detail but hitherto in one center only and in a limited number of patients is glucose polymer (generic name, icodextrin). Because of the promise shown by these initial studies, a randomized controlled multicenter investigation of icodextrin in CAPD (MIDAS Study Group) was undertaken to evaluate the long-term safety and efficacy by comparing daily overnight (8 12 hours) use of a slightly hypo-osmolar solution (282 mOsm/ kg) with 1.36% (346 mOsm/kg) and 3.86% (484 mOsm/kg) glucose exchanges. Over a 6-month period 209 patients from 11 centers in the United Kingdom were randomized, with 106 allocated to receive icodextrin (study group) and 103 to remain on glucose (control group). One hundred and thirty-eight patients completed the 6-month study (71 control, 67 study).

The mean net ultrafiltration overnight with icodextrin was 3.5 times greater than 1.36% at 8 hours and 5.5 times greater at 12 hours (p<0.0001), but no different from that of 3.86% glucose at 8 and 12 hours (although for the latter dwell the net mean ultrafiltration volume was greater by about 140 mL). Biochemical profiles were no different except for a small fall in serum sodium and chloride in the icodextrin group. The mean serum maltose rose to a steady-state level of 1.2 g/L within 2 weeks and remained stable. The mean carbohydrate absorbed for icodextrin (29±5 g) was lower than with 3.86% glucose (62±5 g). The use of icodextrin did not increase the incidence of peritonitis, nor did it alter its outcome, affect uptake of icodextrin from the peritoneum, alter serum osmolality or sodium levels. There were no adverse effects associated with the use of icodextrin, and the overall CAPD-related symptom score was significantly better for icodextrin than control subjects.

This study and subsequent extensive use and clinical experience has demonstrated that the daily use of an iso-osmolar icodextrin solution is generally well tolerated, effective, and could replace the overnight use of hyperosmotic glucose solution. Its use was of equal efficacy in peritonitis and in diabetic patients. The elevated levels of maltose did not appear to have any clinical side effects.

Peritonitis Occurrence in a Multicenter Study of Icodextrin and Glucose in Capd

Objective

To compare peritonitis occurrence and outcome in a large U.K. study Multicentre Investigation of Icodextrin in Ambulatory Dialysis (MIDAS).

Design

Prospective, randomized, controlled 6-month comparison of icodextrin with glucose for the long dwell in continuous ambulatory peritoneal dialysis (CAPD) patients.

Setting

Eleven CAPD units in U.K. teaching hospitals.

Patients

A total of 209 patients established on CAPD for at least 3 months (103 control, 106 icodextrin). Twentythree control (C) and 22 icodextrin (I) patients experienced peritonitis during the study.

Intervention

Patients who had peritonitis remained on treatment (unless CAPD was withdrawn, temporarily or permanently).

Main Outcome Measures

The main outcome measures were the rate of peritonitis and duration of CAPD treatment prestudy; the rate of peritonitis episodes and their outcome during study; the effect of peritonitis on laboratory variables, serum icodextrin metabolites, and ultrafiltration efficacy.

Results

Prestudy: Nine (39%) of C but 14 (64%) of I patients had suffered previous peritonitis episode(s), with overall rates of 0.58 and 0.78 episodes per patientyear, respectively.

During study

There were 31 C episodes and 35 I episodes, with overall rates of 0.76 and 0.93 per patientyear, respectively. The increase in the C and I groups was 31% and 19%, respectively. Serum osmolality and sodium levels were unaffected by peritonitis, and there was no increase in serum icodextrin metabolites during peritonitis. Overnight ultrafiltration volume during peritonitis (mean±SD) declined slightly from 218±354 mL to 185±299 mL (NS) in the control group, but increased in the icodextrin group from 570±146 mL to 723±218 mL (p < 0.01).

Conclusions

Using icodextrin for the long dwell in CAPD does not increase the rate of peritonitis, nor does it alter the outcome of peritonitis. Peritonitis does not affect uptake of icodextrin from the peritoneum.

Incorporating non-stomatal limitation improves the performance of leaf and canopy models at high vapour pressure deficit

Vapour pressure deficit (D) is projected to increase in the future as temperature rises. In response to increased D, stomatal conductance (gs) and photosynthesis (A) are reduced, which may result in significant reductions in terrestrial carbon, water and energy fluxes. It is thus important for gas exchange models to capture the observed responses of gs and A with increasing D. We tested a series of coupled A-gs models against leaf gas exchange measurements from the Cumberland Plain Woodland (Australia), where D regularly exceeds 2 kPa and can reach 8 kPa in summer. Two commonly used A-gs models were not able to capture the observed decrease in A and gs with increasing D at the leaf scale. To explain this decrease in A and gs, two alternative hypotheses were tested: hydraulic limitation (i.e., plants reduce gs and/or A due to insufficient water supply) and non-stomatal limitation (i.e., downregulation of photosynthetic capacity). We found that the model that incorporated a non-stomatal limitation captured the observations with high fidelity and required the fewest number of parameters. Whilst the model incorporating hydraulic limitation captured the observed A and gs, it did so via a physical mechanism that is incorrect. We then incorporated a non-stomatal limitation into the stand model, MAESPA, to examine its impact on canopy transpiration and gross primary production. Accounting for a non-stomatal limitation reduced the predicted transpiration by ~19%, improving the correspondence with sap flow measurements, and gross primary production by ~14%. Given the projected global increases in D associated with future warming, these findings suggest that models may need to incorporate non-stomatal limitation to accurately simulate A and gs in the future with high D. Further data on non-stomatal limitation at high D should be a priority, in order to determine the generality of our results and develop a widely applicable model.

Brain lateralization probed by water diffusion at the atomic to micrometric scale

Combined neutron scattering and diffusion nuclear magnetic resonance experiments have been used to reveal significant interregional asymmetries (lateralization) in bovine brain hemispheres in terms of myelin arrangement and water dynamics at micron to atomic scales. Thicker myelin sheaths were found in the left hemisphere using neutron diffraction. 4.7 T dMRI and quasi-elastic neutron experiments highlighted significant differences in the properties of water dynamics in the two hemispheres. The results were interpreted in terms of hemisphere-dependent cellular composition (number of neurons, cell distribution, etc.) as well as specificity of neurological functions (such as preferential networking).

Early suppression of peripheral mononuclear blood cells in sepsis in response to stimulation with cytomegalovirus, OKT3, and pokeweed mitogen

Critically ill patients are at risk for sepsis, and immunosuppressive mechanisms may prevail. Whether functional tests are helpful to detect immune alterations is largely unknown. Therefore, we tested the hypotheses that reactivity of peripheral blood mononuclear cells (PBMCs) to secrete interferon-γ (IFNγ) following stimulation in vitro is decreased in patients with early sepsis compared with postoperative patients. IFNγ secretion [enzyme-linked immunospot (ELISpot)] in response to stimulation with cytomegalovirus (CMV), pokeweed mitogen (PWM), muromonab-anti-CD3 (OKT3), and human leukocyte antigen (HLA)-DRA-mRNA expression and serum cytokine concentrations were repeatedly [days 1, 3, 5, and 7 after intensive care unit (ICU) admission] determined in patients with sepsis (n = 7) and patients undergoing major abdominal surgery (radical prostatectomy, cystectomy, n = 10). In a second cohort, HLA-DRA expression was assessed in 80 patients with sepsis, 30 postoperative patients, and 44 healthy volunteers (German clinical trials database no. 00007694). In patients with sepsis, IFNγ secretion (ELISpot) was decreased compared with controls after stimulation with CMV (P = 0.01), OKT3 (P = 0.02), and PWM (P = 0.02 on day 5), whereas unstimulated IFNγ secretion did not differ. HLA-DRA expression was also significantly decreased in patients with sepsis at all time points (P = 0.004) compared with postoperative surgical patients, a finding confirmed in the larger cohort. Reactivity of PBMCs to stimulation with CMV, PWM, and OKT3 as well as HLA-DRA expression was already decreased upon ICU admission in patients with sepsis when compared with postoperative controls, suggesting early depression of acquired immunity. ELISpot assays may help to clinically characterize the time course of immunocompetence in patients with sepsis.NEW & NOTEWORTHY We observed suppression of reactivity to stimulation with cytomegalovirus, muromonab-anti-CD3, and pokeweed mitogen in mononuclear blood cells of patients with early sepsis when compared with postoperative controls. Thus, there is early depression of acquired immunity in sepsis. Enzyme-linked immunospot assays may help to characterize immunocompetence in patients with sepsis.

Anomalous water dynamics in brain: a combined diffusion magnetic resonance imaging and neutron scattering investigation

Water diffusion is an optimal tool for investigating the architecture of brain tissue on which modern medical diagnostic imaging techniques rely. However, intrinsic tissue heterogeneity causes systematic deviations from pure free-water diffusion behaviour. To date, numerous theoretical and empirical approaches have been proposed to explain the non-Gaussian profile of this process. The aim of this work is to shed light on the physics piloting water diffusion in brain tissue at the micrometre-to-atomic scale. Combined diffusion magnetic resonance imaging and first pioneering neutron scattering experiments on bovine brain tissue have been performed in order to probe diffusion distances up to macromolecular separation. The coexistence of free-like and confined water populations in brain tissue extracted from a bovine right hemisphere has been revealed at the micrometre and atomic scale. The results are relevant for improving the modelling of the physics driving intra- and extracellular water diffusion in brain, with evident benefit for the diffusion magnetic resonance imaging technique, nowadays widely used to diagnose, at the micrometre scale, brain diseases such as ischemia and tumours.

Single Crystal Time-of-Flight Neutron Diffraction

The last century has seen a large development in diffraction techniques. The time-of-flight neutron diffraction method is now so advanced that it provides high precision results for position and thermal parameters, which are complementary to other diffraction results from X-ray sources. Here we review the history of neutron sources, the difficulties encountered with the time-of-flight technique and an outlook for applications. In this context, we will show the limitations of existing neutron sources and the expected advantages of new spallation neutron sources. An overview of all corrections to be taken into account with the wavelength-sorting technique will be presented as well as actual results, how to overcome such problems, and the special difficulty of integration of three-dimensional Bragg peaks.

Analysis of elastic incoherent neutron scattering data beyond the Gaussian approximation

This work addresses the use of the Gaussian approximation as a common tool to extract atomic motions in proteins from elastic incoherent neutron scattering and whether improvements in data analysis and additional information can be obtained when going beyond that. We measured alpha-lactalbumin with different levels of hydration on three neutron backscattering spectrometers, to be able to resolve a wide temporal and spatial range for dynamics. We demonstrate that the Gaussian approximation gives qualitatively similar results to models that include heterogeneity, if one respects a certain procedure to treat the intercept of the elastic intensities with the momentum transfer axis. However, the inclusion of motional heterogeneity provides better fits to the data. Our analysis suggests an approach of limited heterogeneity, where including only two kinds of motions appears sufficient to obtain more quantitative results for the mean square displacement. Finally, we note that traditional backscattering spectrometers pose a limit on the lowest accessible momentum transfer. We therefore suggest that complementary information about the spatial evolution of the elastic intensity close to zero momentum transfer can be obtained using other neutron methods, in particular, neutron spin-echo together with polarization analysis.

Portable Pocket colposcopy performs comparably to standard-of-care clinical colposcopy using acetic acid and Lugol's iodine as contrast mediators: an investigational study in Peru

OBJECTIVE

Our goal was to develop a tele-colposcopy platform for primary-care clinics to improve screening sensitivity and access. Specifically, we developed a low-cost, portable Pocket colposcope and evaluated its performance in a tertiary healthcare centre in Peru.

DESIGN AND SETTING

Images of the cervix were captured with a standard-of-care and Pocket colposcope at la Liga Contra el Cáncer in Lima, Peru.

POPULATION

Two hundred Peruvian women with abnormal cytology and/or human papillomavirus positivity were enrolled.

METHODS

Images were collected using acetic acid and Lugol's iodine as contrast agents. Biopsies were taken as per standard-of-care procedures.

MAIN OUTCOME MEASURES

After passing quality review, images from 129 women were sent to four physicians who provided a diagnosis for each image.

RESULTS

Physician interpretation of images from the two colposcopes agreed 83.1% of the time. The average sensitivity and specificity of physician interpretation compared with pathology was similar for the Pocket (sensitivity = 71.2%, specificity = 57.5%) and standard-of-care (sensitivity = 79.8%, specificity = 56.6%) colposcopes. When compared with a previous study where only acetic acid was applied to the cervix, results indicated that adding Lugol's iodine as a secondary contrast agent improved the percent agreement between colposcopes for all pathological categories by up to 8.9% and the sensitivity and specificity of physician interpretation compared with pathology by over 6.0 and 9.0%, respectively.

CONCLUSIONS

The Pocket colposcope performance was similar to that of a standard-of-care colposcope when used to identify precancerous and cancerous lesions using acetic acid and Lugol's iodine during colposcopy examinations in Peru.

TWEETABLE ABSTRACT

The Pocket colposcope performance was similar to that of a standard-of-care colposcope when identifying cervical lesions.

The effect of pH on the dynamics of natural membranes

Pure phospholipids and membrane fragments from bacterial cells living under various conditions were studied against the influence of the surrounding acidity on the internal dynamics. For that we compared mean square displacements extracted from elastic incoherent neutron scattering data, measured both at low and at neutral pH, of the phospholipids 1,2-dimyristoyl-sn-glycero-3-phosphocholine and of samples from neutralophilic and acidophilic micro-organisms (some being hyperthermophilic and others mesophilic). The lipids showed a slight shift in the phase transition temperature of about 4 degrees under pH variation and became slightly more mobile at lower pH. The membrane fragments not used to extreme acidic conditions were significantly more sensitive to variations in the pH values, whereas the acidophilic and -tolerant samples were much less influenced by this parameter. They presented the higher softness at low pH, which was closer to their native condition. Such findings might be a hint for adaptation mechanisms to different acidity conditions.

Influence of cosolvents, self-crowding, temperature and pressure on the sub-nanosecond dynamics and folding stability of lysozyme

We studied the effects of temperature and hydrostatic pressure on the dynamical properties and folding stability of highly concentrated lysozyme solutions in the absence and presence of the osmolytes trimethylamine-N-oxide (TMAO) and urea. Elastic incoherent neutron scattering (EINS) was applied to determine the mean-squared displacement (MSD) of the protein's hydrogen atoms to yield insights into the effects of these cosolvents on the averaged sub-nanosecond dynamics in the pressure range from ambient up to 4000 bar. To evaluate the additional effect of self-crowding, two protein concentrations (80 and 160 mg mL^-1) were used. We observed a distinct effect of TMAO on the internal hydrogen dynamics, namely a reduced mobility. Urea, on the other hand, revealed no marked effect and consequently, no counteracting effect in an urea-TMAO mixture was observed. Different from the less concentrated protein solution, no significant effect of pressure on the MSD was observed for 160 mg mL^-1 lysozyme. The EINS experiments were complemented by Fourier-transform infrared (FTIR) spectroscopy measurements, which led to additional insights into the folding stability of lysozyme under the various environmental conditions. We observed a stabilization of the protein in the presence of the compatible osmolyte TMAO and a destabilization in the presence of urea against temperature and pressure for both protein concentrations. Additionally, we noticed a slight destabilizing effect upon self-crowding at very high protein concentration (160 mg mL^-1), which is attributable to transient destabilizing intermolecular interactions. Furthermore, a pressure-temperature diagram could be obtained for lysozyme at these high protein concentrations that mimics densely packed intracellular conditions.

Volume of surgery for benign colorectal polyps in the last 11 years

BACKGROUND AND AIMS

Traditionally large, complex colorectal polyps were managed by surgical resection (SR), and in recent years endoscopic resection (ER) has progressed significantly. However, to what extent ER has replaced SR remains largely unknown. We performed a multicenter retrospective cohort study to assess the volume and volume changes of SR for benign colorectal polyps over the past decade.

METHODS

Patients who underwent SR for a benign colorectal polyp in the Netherlands between 2005 and 2015 were selected from the prospective nationwide Dutch Pathology Registry (PALGA database). Clinical characteristics were obtained from the charts of patients who underwent SR in the province of Noord-Holland.

RESULTS

A total of 5937 patients were treated with SR for a colorectal polyp and the absolute (454-739 per year) and relative volumes (0.20%-0.37% per colonoscopy per year) of SR remained stable. In the province of Noord-Holland, 928 patients (15.6%) underwent SR. In these patients, submucosal lifting and ER were attempted in 19.9% (n = 175) and 15.0% (n = 134). After 2010, patients were more likely to undergo lifting (27.7% vs 11.4%, P < .001) and ER attempts (18.8% vs 10.9%, P = .001) before definitive SR. Twenty-two patients (2.4%) had been referred to another endoscopy clinic.

CONCLUSIONS

SR for large, complex colorectal polyps is still frequently performed and has remained stable. A small percentage of patients underwent ER attempts before SR, and referral for an additional ER attempt only occurred in a minority of cases. To increase ER attempts, implementation of a regional multidisciplinary referral network should be considered.

Thermodynamics of lipid multi-lamellar vesicles in presence of sterols at high hydrostatic pressure

We compared the effect of cholesterol at different concentration on the phase behaviour of DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) multilamellar vesicles. We used pressure perturbation differential scanning calorimetry (PPC) that studies a system on the whole by giving access to relevant thermodynamic quantities, and elastic incoherent neutron scattering (EINS) that probes local motions of a system at the atomic level by allowing extraction of dynamical parameters. PPC revealed that the volume expansion coefficient of DMPC and DMPC/Cholesterol samples with 13 and 25 mol% cholesterol is a linear function of the heat capacity measured by differential scanning calorimetry. Neutron backscattering spectroscopy showed that the mean square displacements of H atoms do exhibit an increase with temperature and a decrease under increasing pressure. Cholesterol added at concentrations of 25 and 50 mol% led to suppression of the main phase transition. Taking advantage of these results, the present study aims (i) to show that calorimetry and EINS using the Bicout and Zaccai model equally permit to get access to thermodynamic quantities characterizing pure DMPC and DMPC/cholesterol mixtures, thus directly confirming the theoretical method, and (ii) to validate our approach as function of temperature and of pressure, as both are equally important and complementary thermodynamic variables.

Selective increase of cerebrospinal fluid IL-6 during experimental systemic inflammation in humans: association with depressive symptoms

Systemic inflammation is accompanied by profound behavioral and mood changes that resemble symptoms of depression. Findings in animals suggest that pro-inflammatory cytokines released by activated immune cells in the periphery evoke these behavioral symptoms by driving inflammatory changes in the brain. However, experimental data in humans are lacking. Here we demonstrate in healthy male volunteers (10 endotoxin treated, 8 placebo treated) that intravenous administration of low-dose endotoxin (0.8 ng/kg body weight), a prototypical pathogen-associated molecular pattern that activates the innate immune system, not only induces a significant increase in peripheral blood cytokine concentrations (that is, tumor necrosis factor-α, interleukin (IL)-6, IL-10) but also results, with some latency, in a robust and selective increase of IL-6 in the cerebrospinal fluid (CSF). Moreover, we found a strong association between the endotoxin-induced increase of IL-6 in the CSF and the severity of mood impairment, with larger increases in CSF IL-6 concentration followed by a greater deterioration in mood. Taken together, these findings suggest that the appearance of depressive symptoms in inflammatory conditions might be primarily linked to an increase in central IL-6 concentration, identifying IL-6 as a potential therapeutic target in mood disorders.

Low-density lipoproteins investigated under high hydrostatic pressure by elastic incoherent neutron scattering

Human low-density lipoprotein (LDL) is a highly complex nano-particle built up of various lipid classes and a single large protein moiety (apoB-100) owning essential physiological functions in the human body. Besides its vital role as a supplier of cholesterol and fat for peripheral tissues and cells, it is also a known key player in the formation of atherosclerosis. Due to these important roles in physiology and pathology the elucidation of structural and dynamical details is of great interest. In the current study we drew a broader picture of LDL dynamics using elastic incoherent neutron scattering (EINS) as a function of specified temperature and pressure points. We not only investigated a normolipidemic LDL sample, but also a triglyceride-rich and an oxidized one to mimic pathologic conditions as found under hyperlipidemic conditions or in atherosclerotic plaques, respectively. We could show that pressure has a significant effect on atomic motions in modified forms of LDL, whereas the normolipidemic sample seems to cope much better with high-pressure conditions irrespective of temperature. These findings might be explained by the altered lipid composition, which is either caused through elevated triglyceride content or modifications through lipid peroxidation.

High hydrostatic pressure specifically affects molecular dynamics and shape of low-density lipoprotein particles

Lipid composition of human low-density lipoprotein (LDL) and its physicochemical characteristics are relevant for proper functioning of lipid transport in the blood circulation. To explore dynamical and structural features of LDL particles with either a normal or a triglyceride-rich lipid composition we combined coherent and incoherent neutron scattering methods. The investigations were carried out under high hydrostatic pressure (HHP), which is a versatile tool to study the physicochemical behavior of biomolecules in solution at a molecular level. Within both neutron techniques we applied HHP to probe the shape and degree of freedom of the possible motions (within the time windows of 15 and 100 ps) and consequently the flexibility of LDL particles. We found that HHP does not change the types of motion in LDL, but influences the portion of motions participating. Contrary to our assumption that lipoprotein particles, like membranes, are highly sensitive to pressure we determined that LDL copes surprisingly well with high pressure conditions, although the lipid composition, particularly the triglyceride content of the particles, impacts the molecular dynamics and shape arrangement of LDL under pressure.

Changes in dynamics of α-chymotrypsin due to covalent inhibitors investigated by elastic incoherent neutron scattering

The dynamics of chymotrypsin increases when bound to two different covalent inhibitors. These effects were analyzed by univariate and multivariate methods.

Guidelines for the diagnosis, prevention and management of chemical- and radiation-induced cystitis

Objective

Haemorrhagic cystitis (HC) is a relatively common complication of chemotherapy and radiotherapy to the pelvic area, but can be a challenging condition to treat, particularly since there is currently a lack of UK-led guidelines available on how it should optimally be defined and managed.

Materials and methods

A comprehensive literature search was undertaken to evaluate the evidence for the diagnosis, prevention and management of cancer treatment-induced HC.

Results

Recommendations and a proposed management algorithm for the diagnosis, prevention and treatment of HC, as well as the management of intractable haematuria, have been developed based on the expert opinion of the multidisciplinary consensus panel following a comprehensive review of the available clinical data.

Conclusion

These guidelines are relevant and applicable to current clinical practice and will help clinicians optimally define and manage this potentially serious condition.

Gram-negative bacteraemia; a multi-centre prospective evaluation of empiric antibiotic therapy and outcome in English acute hospitals

Increasing antibiotic resistance makes choosing antibiotics for suspected Gram-negative infection challenging. This study set out to identify key determinants of mortality among patients with Gram-negative bacteraemia, focusing particularly on the importance of appropriate empiric antibiotic treatment. We conducted a prospective observational study of 679 unselected adults with Gram-negative bacteraemia at ten acute english hospitals between October 2013 and March 2014. Appropriate empiric antibiotic treatment was defined as intravenous treatment on the day of blood culture collection with an antibiotic to which the cultured organism was sensitive in vitro. Mortality analyses were adjusted for patient demographics, co-morbidities and illness severity. The majority of bacteraemias were community-onset (70%); most were caused by Escherichia coli (65%), Klebsiella spp. (15%) or Pseudomonas spp. (7%). Main foci of infection were urinary tract (51%), abdomen/biliary tract (20%) and lower respiratory tract (14%). The main antibiotics used were co-amoxiclav (32%) and piperacillin-tazobactam (30%) with 34% receiving combination therapy (predominantly aminoglycosides). Empiric treatment was inappropriate in 34%. All-cause mortality was 8% at 7 days and 15% at 30 days. Independent predictors of mortality (p <0.05) included older age, greater burden of co-morbid disease, severity of illness at presentation and inflammatory response. Inappropriate empiric antibiotic therapy was not associated with mortality at either time-point (adjusted OR 0.82; 95% CI 0.35-1.94 and adjusted OR 0.92; 95% CI 0.50-1.66, respectively). Although our study does not exclude an impact of empiric antibiotic choice on survival in Gram-negative bacteraemia, outcome is determined primarily by patient and disease factors.

Influence of myelin proteins on the structure and dynamics of a model membrane with emphasis on the low temperature regime

Myelin is an insulating, multi-lamellar membrane structure wrapped around selected nerve axons. Increasing the speed of nerve impulses, it is crucial for the proper functioning of the vertebrate nervous system. Human neurodegenerative diseases, such as multiple sclerosis, are linked to damage to the myelin sheath through demyelination. Myelin exhibits a well defined subset of myelin-specific proteins, whose influence on membrane dynamics, i.e., myelin flexibility and stability, has not yet been explored in detail. In a first paper [W. Knoll, J. Peters, P. Kursula, Y. Gerelli, J. Ollivier, B. Demé, M. Telling, E. Kemner, and F. Natali, Soft Matter 10, 519 (2014)] we were able to spotlight, through neutron scattering experiments, the role of peripheral nervous system myelin proteins on membrane stability at room temperature. In particular, the myelin basic protein and peripheral myelin protein 2 were found to synergistically influence the membrane structure while keeping almost unchanged the membrane mobility. Further insight is provided by this work, in which we particularly address the investigation of the membrane flexibility in the low temperature regime. We evidence a different behavior suggesting that the proton dynamics is reduced by the addition of the myelin basic protein accompanied by negligible membrane structural changes. Moreover, we address the importance of correct sample preparation and characterization for the success of the experiment and for the reliability of the obtained results.

The Colored, Eco-Genetic Relationship Map (CEGRM): A Conceptual Approach and Tool for Genetic Counseling Research

The Colored Ecological and Genetic Relational Map (CEGRM) [pronounced see-gram] is a conceptual approach and tool for presenting information about family and nonkin relationships and stories about inherited diseases in a simple, understandable form. It combines information that can be derived from pedigrees, genograms, ecomaps, and social network analysis in a single, or series of, pictorial maps based on colors and shapes. The CEGRM is based on a social systems perspective, particularly emphasizing social exchange and resource theories. The CEGRM should be particularly useful in genetic counseling research with members of suspected cancer-risk families or families with other late-onset inherited diseases. A genetic counseling client comes with a social history and context as well as a genetic one. Client decision-making in terms of reproductive plans, therapeutic intervention, lifestyle behavior and sharing or withholding of genetic information frequently becomes enmeshed with preexisting psycho-social relationships among biological kin, affinal kin (in-laws) and fictive kin (friends who act as family). The CEGRM makes it easier to compare different types of social interactions between the client and his/her significant others and among family members on the same dimensions.