Ligand-Mediated Control of the Surface Oxidation States of Copper Nanoparticles Produced by Laser Ablation

We report on studies that demonstrate how the chemical composition of the surface of copper nanoparticles (CuNPs) - in terms of percentage copper(I/II) oxides - can be varied by the presence of N-donor ligands during their formation via laser ablation. Changing the chemical composition thus allows systematic tuning of the surface plasmon resonance (SPR) transition. The trialed ligands include pyridines, tetrazoles, and alkylated tetrazoles. CuNPs formed in the presence of pyridines, and alkylated tetrazoles exhibit a SPR transition only slightly blue shifted with respect to CuNPs formed in the absence of any ligand. On the other hand, the presence of tetrazoles results in CuNPs characterized by a significant blue shift of the order of 50-70 nm. By comparing these data also with the SPR of CuNPs formed in the presence of carboxylic acids and hydrazine, this work demonstrates that the blue shift in the SPR is due to tetrazolate anions providing a reducing environment to the nascent CuNPs, thus preventing the formation of copper(II) oxides. This conclusion is further supported by the fact that both AFM and TEM data indicate only small variations in the size of the nanoparticles, which is not enough to justify a 50-70 nm blue-shift of the SPR transition. High-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) studies further confirm the absence of Cu(II)-containing CuNPs when prepared in the presence of tetrazolate anions.

POS0739 THE RENAL ACTIVITY INDEX FOR LUPUS (RAIL) DIFFERENTIATES ACTIVE AND INACTIVE NEPHRITIS IN ADULT PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)

Background

Lupus nephritis (LN) confers a poor prognosis, with lack of effective laboratory tests to diagnose and evaluate therapies. We have demonstrated that the RAIL score, based on a set of six urinary biomarkers (NGAL, KIM-1, MCP-1, adiponectin, hemopexin, ceruloplasmin) is sensitive and specific in adult patients with active LN, using renal biopsy as reference.1,2 RAIL has been shown in the pediatric population to be effective in distinguishing inactive vs active LN with no effect from mycophenolate mofetil (MMF) treatment. A comparable study has not been conducted in an adult population.

Objectives

To assess the ability of RAIL to discriminate patients with active LN vs active non-renal SLE and to evaluate if RAIL performance varies by MMF treatment using urine samples from adult LN patients.

Methods

Urine samples were obtained at baseline in two clinical trials: a phase 2 study in adult patients with biopsy-proven active Class III and IV LN (NCT02547922) and a subset of patients from the phase 3 trial in adults with active non-renal SLE (NCT02446912) who had baseline renal BILAG scores C, D, or E. RAIL biomarkers were assayed using single-plex assays. Patient demographics and clinical characteristics were compared between studies. Wilcoxon rank sum test was performed comparing the urinary biomarkers between the two studies and RAIL score was then calculated. Receiver operating characteristic (ROC) analyses were conducted assessing the ability for RAIL scores to distinguish patients with renal activity and involvement.

Results

Comparison of the patient demographic, clinical characteristics, and biomarkers is in the Table 1. Wilcoxon rank sum test showed the six urinary biomarkers were significantly different between two groups of patients as demonstrated (Table 1). Each of the RAIL biomarker concentrations and the creatinine-adjusted median score were higher in the active LN group than the SLE group (P<0.001). ROC analyses including RAIL score showed an area under the ROC curve of 0.8 (Figure 1), with odds ratio of log-transformed RAIL 2.027 (95% CI [1.587, 2.589]). There were no significant interactions between RAIL and MMF. RAIL remained significant after adjusting for estimated glomerular filtration rate (eGFR), which was not statistically significant.

Table 1.

Study Demographics and Biomarkers

VariablesLN study (N=131)SLE study (N=59)Observed NObserved Median (IQR) or %Observed NObserved Median (IQR) or %DemographicsAge13134 (25, 42)5936 (28, 44)Sex, Female10983.21%5593.22%Race, White5642.75%4576.27%Ethnicity, Hispanic or Latino6146.56%915.25%OCS use, yes12797.69%5796.61%MMF use, yes9572.52%2135.59%Spot UPCR (mg/mg)1282.13 (1.22, 4.04)591.11 (0.55, 2.61)eGFR13091.8 (63.1, 125)5998.06 (81.91, 116.54)Non-renal SLEDAI-2K score1304 (4, 6)5912 (9, 13)Renal SLEDAI-2K score1304 (4, 8)590 (0, 0)BiomarkersNGAL (ng/mL)12833.33 (17.55, 56.7)5819.47 (11.37, 42.05)MCP-1 (pg/mL)128658.24 (271.58, 1049.95)58275.62 (106.09, 481.99)Ceruloplasmin (ng/mL)12893.55 (44.5, 311.25)5847.2 (13.05, 231.25)Adiponectin (ng/mL)12842.45 (16.71, 139.64)589.33 (3.35, 25.51)Hemopexin (ng/mL)1281876.8 (745.07, 4743.4)58513.4 (236.36, 1388.74)KIM-1 (pg/mL)1281673.5 (772.5, 2767)58864 (394, 1480)Creatinine (mg/mL)1280.7 (0.46, 1.3)580.99 (0.46, 1.74)Adult RAIL score (creatinine adjusted)1285.59 (4.31, 6.47)583.57 (2.78, 4.47)

eGFR, estimated glomerular filtration rate; IQR, interquartile range; KIM, kidney injury molecule; LN, lupus nephritis; MCP, monocyte chemotactic protein; MMF, mycophenolate mofetil; NGAL, neutrophil gelatinase-associated lipocalin; OCS, oral corticosteroid; SLEDAI-2K, SLE Disease Activity Index 2000; UPCR, urine protein/creatinine ratio.

Conclusion

The analyses performed suggest that creatinine-corrected RAIL discriminates between active LN and non-renal adult SLE, with RAIL scores not influenced by MMF use.

References

[1]Brunner HI. Arthritis Care Res (Hoboken). 2016;68:1003–11.

[2]Gulati G. Lupus. 2017;26:927–36.

Acknowledgements

Writing assistance by Kelly M. Hunter, PhD (Fishawack). This study was sponsored by AstraZeneca.

Disclosure of Interests

Ellen Cody: None declared, Hermine Brunner Speakers bureau: Novartis, Pfizer, GSK, Consultant of: AbbVie, Astra Zeneca-Medimmune, Biogen, Boehringer, Bristol Myers Squibb, Celgene, Lilly,EMD Serono, Idorsia, Cerocor, Janssen, GSK, F. Hoffmann-La Roche, Merck, Novartis, R-Pharm, Sanofi, Grant/research support from: Pfizer, Bin Huang: None declared, Tingting Qiu: None declared, Prasad Devarajan Speakers bureau: Reata, Alnylam, Dicerna, Consultant of: BioPorto Inc, Madhu Ramaswamy Shareholder of: AstraZeneca, Employee of: AstraZeneca, Dominic Sinibaldi Shareholder of: AstraZeneca, Employee of: AstraZeneca, Philip Z Brohawn Shareholder of: AstraZeneca, Employee of: AstraZeneca, Jacob Knagenhjelm Shareholder of: AstraZeneca, Employee of: AstraZeneca, Frederick Jones Shareholder of: AstraZeneca, Employee of: AstraZeneca, Raj Tummala Shareholder of: AstraZeneca, Employee of: AstraZeneca, Catharina Lindholm Employee of: AstraZeneca, Wendy White Shareholder of: AstraZeneca, Employee of: AstraZeneca

An initial evaluation of narrative exposure therapy as a treatment of posttraumatic stress disorder among Sudanese refugees in Cairo, delivered by lay counselors

Background

The growing worldwide refugee crisis highlights the needs for increased access to mental health services, including in the large urban cities in the Middle East to which refugees are frequently displaced and in which access to such services is limited. The current study offers an initial evaluation of narrative exposure therapy as a treatment for posttraumatic stress disorder among Sudanese refugees in Cairo, delivered by lay counselors. Sudanese refugees with no prior background in counseling were given 27 h of training in narrative exposure therapy. They then delivered this to seven members of the same refugee community with a diagnosis of posttraumatic stress disorder at a local community center, and this was evaluated using a pre-post design and a focus-group with the intervention recipients.

Results

Despite the small sample size, over the course of the intervention there was significant decrease in trauma and anxiety symptoms, and a close to significant decrease in depression. Moreover, the focus group participants generally spoke positively about their experiences.

Conclusions

To the best of the authors’ knowledge, this is the first study to examine the viability of lay counselors delivering narrative exposure therapy to refugees with posttraumatic stress disorder in a complex urban setting. The findings suggest that this approach has promise and support the case for a randomized control trial of narrative exposure therapy delivered in this manner in such a setting.

Calcium oxalate crystallization in synthetic urinary medium: the impact of resorcinares and calixarenes

The impact of macrocycles on calcium oxalate formation. Calcium oxalate is a major component of kidney stones, an ailment that affects many people globally.

In-situ atomic force microscopic (AFM) investigation of kaolinite dissolution in high caustic environments

Clays are a common component of bauxite and reactive silica, in the form of clays, is an important precursor of desilication products. Despite this, the behaviour or clays in highly...

Spontaneous formation of barium sulfate crystals at liquid–liquid interfaces

Interfacial ion transfer from organic phase to aqueous phase is employed as the basis for formation of barium sulfate crystals close to the interface.

Electrochemically controlled cocrystallisation of caffeine:1-hydroxy-2-naphthoic acid

The formation of caffeine and 1-hydroxy-2-naphtoic acid cocrystals at a water–oil interface was controlled by potential difference, Δwoϕ, favouring one polymorphic form of the cocrystal.

SARS-CoV-2 seropositivity and subsequent infection risk in healthy young adults: a prospective cohort study

Background

Whether young adults who are infected with SARS-CoV-2 are at risk of subsequent infection is uncertain. We investigated the risk of subsequent SARS-CoV-2 infection among young adults seropositive for a previous infection.

Methods

This analysis was performed as part of the prospective COVID-19 Health Action Response for Marines study (CHARM). CHARM included predominantly male US Marine recruits, aged 18–20 years, following a 2-week unsupervised quarantine at home. After the home quarantine period, upon arrival at a Marine-supervised 2-week quarantine facility (college campus or hotel), participants were enrolled and were assessed for baseline SARS-CoV-2 IgG seropositivity, defined as a dilution of 1:150 or more on receptor-binding domain and full-length spike protein ELISA. Participants also completed a questionnaire consisting of demographic information, risk factors, reporting of 14 specific COVID-19-related symptoms or any other unspecified symptom, and brief medical history. SARS-CoV-2 infection was assessed by PCR at weeks 0, 1, and 2 of quarantine and participants completed a follow-up questionnaire, which included questions about the same COVID-19-related symptoms since the last study visit. Participants were excluded at this stage if they had a positive PCR test during quarantine. Participants who had three negative swab PCR results during quarantine and a baseline serum serology test at the beginning of the supervised quarantine that identified them as seronegative or seropositive for SARS-CoV-2 then went on to basic training at Marine Corps Recruit Depot—Parris Island. Three PCR tests were done at weeks 2, 4, and 6 in both seropositive and seronegative groups, along with the follow-up symptom questionnaire and baseline neutralising antibody titres on all subsequently infected seropositive and selected seropositive uninfected participants (prospective study period).

Findings

Between May 11, 2020, and Nov 2, 2020, we enrolled 3249 participants, of whom 3168 (98%) continued into the 2-week quarantine period. 3076 (95%) participants, 2825 (92%) of whom were men, were then followed up during the prospective study period after quarantine for 6 weeks. Among 189 seropositive participants, 19 (10%) had at least one positive PCR test for SARS-CoV-2 during the 6-week follow-up (1·1 cases per person-year). In contrast, 1079 (48%) of 2247 seronegative participants tested positive (6·2 cases per person-year). The incidence rate ratio was 0·18 (95% CI 0·11–0·28; p<0·001). Among seropositive recruits, infection was more likely with lower baseline full-length spike protein IgG titres than in those with higher baseline full-length spike protein IgG titres (hazard ratio 0·45 [95% CI 0·32–0·65]; p<0·001). Infected seropositive participants had viral loads that were about 10-times lower than those of infected seronegative participants (ORF1ab gene cycle threshold difference 3·95 [95% CI 1·23–6·67]; p=0·004). Among seropositive participants, baseline neutralising titres were detected in 45 (83%) of 54 uninfected and in six (32%) of 19 infected participants during the 6 weeks of observation (ID50 difference p<0·0001).

Interpretation

Seropositive young adults had about one-fifth the risk of subsequent infection compared with seronegative individuals. Although antibodies induced by initial infection are largely protective, they do not guarantee effective SARS-CoV-2 neutralisation activity or immunity against subsequent infection. These findings might be relevant for optimisation of mass vaccination strategies.

Funding

Defense Health Agency and Defense Advanced Research Projects Agency.

Barium sulfate crystallization in non-aqueous solvent

The dielectric constant impacts on oriented attachment as well as solubility and morphology.

SARS-CoV-2 Transmission among Marine Recruits during Quarantine

BACKGROUND

The efficacy of public health measures to control the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has not been well studied in young adults.

METHODS

We investigated SARS-CoV-2 infections among U.S. Marine Corps recruits who underwent a 2-week quarantine at home followed by a second supervised 2-week quarantine at a closed college campus that involved mask wearing, social distancing, and daily temperature and symptom monitoring. Study volunteers were tested for SARS-CoV-2 by means of quantitative polymerase-chain-reaction (qPCR) assay of nares swab specimens obtained between the time of arrival and the second day of supervised quarantine and on days 7 and 14. Recruits who did not volunteer for the study underwent qPCR testing only on day 14, at the end of the quarantine period. We performed phylogenetic analysis of viral genomes obtained from infected study volunteers to identify clusters and to assess the epidemiologic features of infections.

RESULTS

A total of 1848 recruits volunteered to participate in the study; within 2 days after arrival on campus, 16 (0.9%) tested positive for SARS-CoV-2, 15 of whom were asymptomatic. An additional 35 participants (1.9%) tested positive on day 7 or on day 14. Five of the 51 participants (9.8%) who tested positive at any time had symptoms in the week before a positive qPCR test. Of the recruits who declined to participate in the study, 26 (1.7%) of the 1554 recruits with available qPCR results tested positive on day 14. No SARS-CoV-2 infections were identified through clinical qPCR testing performed as a result of daily symptom monitoring. Analysis of 36 SARS-CoV-2 genomes obtained from 32 participants revealed six transmission clusters among 18 participants. Epidemiologic analysis supported multiple local transmission events, including transmission between roommates and among recruits within the same platoon.

CONCLUSIONS

Among Marine Corps recruits, approximately 2% who had previously had negative results for SARS-CoV-2 at the beginning of supervised quarantine, and less than 2% of recruits with unknown previous status, tested positive by day 14. Most recruits who tested positive were asymptomatic, and no infections were detected through daily symptom monitoring. Transmission clusters occurred within platoons. (Funded by the Defense Health Agency and others.).

Using Molecular Modelling to Understand and Predict the Impact of Organic Additives as Crystal Growth Modifiers

Empirical molecular modelling was used to investigate the impact of organic additives on crystal morphology and inhibition. The replacement energy was found to correlate reasonably well with the degree of inhibition as determined from conductivity data. The replacement energy was also able to predict the barium sulfate face on which additive adsorption was most likely. While the ability of the organic functional groups to sit in the vacant sulfate lattice positions (the so-called ‘lattice matching’ criteria) appears intuitively sensible, it was found that this is not a sufficient criterion to predict real behaviour. A better criterion is the overall replacement energy as it takes into consideration the number of Ba–Oorganic interactions and whether the adsorption process overall is energetically favourable (by including the hydration energy of the ions). Thus, the replacement energy can successfully predict the effect of organic molecules on the crystal growth modification of barium sulfate.

Can macrocyclic phosphonate molecules inhibit barium sulfate crystallization?

Macrocyclic compounds such as DOTP and NOTP are found to inhibit precipitation of barium sulfate just as potently as their non-cyclic counterparts depending on the ionisation state of the molecule.

Concordance of blood- and tumor-based detection of RAS mutations to guide anti-EGFR therapy in metastatic colorectal cancer

Background

Circulating tumor DNA (ctDNA) is a potential source for tumor genome analysis. We explored the concordance between the mutational status of RAS in tumor tissue and ctDNA in metastatic colorectal cancer (mCRC) patients to establish eligibility for anti-epidermal growth factor receptor (EGFR) therapy.

Patients and methods

A prospective-retrospective cohort study was carried out. Tumor tissue from 146 mCRC patients was tested for RAS status with standard of care (SoC) PCR techniques, and Digital PCR (BEAMing) was used both in plasma and tumor tissue.

Results

ctDNA BEAMing RAS testing showed 89.7% agreement with SoC (Kappa index 0.80; 95% CI 0.71 − 0.90) and BEAMing in tissue showed 90.9% agreement with SoC (Kappa index 0.83; 95% CI 0.74 − 0.92). Fifteen cases (10.3%) showed discordant tissue-plasma results. ctDNA analysis identified nine cases of low frequency RAS mutations that were not detected in tissue, possibly due to technical sensitivity or heterogeneity. In six cases, RAS mutations were not detected in plasma, potentially explained by low tumor burden or ctDNA shedding. Prediction of treatment benefit in patients receiving anti-EGFR plus irinotecan in second- or third-line was equivalent if tested with SoC PCR and ctDNA. Forty-eight percent of the patients showed mutant allele fractions in plasma below 1%.

Conclusions

Plasma RAS determination showed high overall agreement and captured a mCRC population responsive to anti-EGFR therapy with the same predictive level as SoC tissue testing. The feasibility and practicality of ctDNA analysis may translate into an alternative tool for anti-EGFR treatment selection.

Plasma ctDNA RAS mutation analysis for the diagnosis and treatment monitoring of metastatic colorectal cancer patients

Background

RAS assessment is mandatory for therapy decision in metastatic colorectal cancer (mCRC) patients. This determination is based on tumor tissue, however, genotyping of circulating tumor (ct)DNA offers clear advantages as a minimally invasive method that represents tumor heterogeneity. Our study aims to evaluate the use of ctDNA as an alternative for determining baseline RAS status and subsequent monitoring of RAS mutations during therapy as a component of routine clinical practice.

Patients and methods

RAS mutational status in plasma was evaluated in mCRC patients by OncoBEAM™ RAS CRC assay. Concordance of results in plasma and tissue was retrospectively evaluated. RAS mutations were also prospectively monitored in longitudinal plasma samples from selected patients.

Results

Analysis of RAS in tissue and plasma samples from 115 mCRC patients showed a 93% overall agreement. Plasma/tissue RAS discrepancies were mainly explained by spatial and temporal tumor heterogeneity. Analysis of clinico-pathological features showed that the site of metastasis (i.e. peritoneal, lung), the histology of the tumor (i.e. mucinous) and administration of treatment previous to blood collection negatively impacted the detection of RAS in ctDNA. In patients with baseline mutant RAS tumors treated with chemotherapy/antiangiogenic, longitudinal analysis of RAS ctDNA mirrored response to treatment, being an early predictor of response. In patients RAS wt, longitudinal monitoring of RAS ctDNA revealed that OncoBEAM was useful to detect emergence of RAS mutations during anti-EGFR treatment.

Conclusion

The high overall agreement in RAS mutational assessment between plasma and tissue supports blood-based testing with OncoBEAM™ as a viable alternative for genotyping RAS of mCRC patients in routine clinical practice. Our study describes practical clinico-pathological specifications to optimize RAS ctDNA determination. Moreover, OncoBEAM™ is useful to monitor RAS in patients undergoing systemic therapy to detect resistance and evaluate the efficacy of particular treatments.

Thermal annealing behaviour and gel to crystal transition of a low molecular weight hydrogelator

The thermal annealing behaviour of an electrolyte-triggered calixarene hydrogelator is found to depend strongly on the specific metal chloride used. While the lithium chloride gel showed typical gel-sol transitions as a function of temperature, the magnesium chloride gel was found to repeatedly strengthen with heat-cool cycles. Structural investigations using small-angle neutron scattering, and scanning probe microscopy, suggest that the annealing behaviour is associated with a change in morphology of the fibrous structures supporting the gel. On prolonged standing at room temperature, the magnesium chloride gel underwent a gel-crystal transition, with the collapsing gel accompanied by the deposition of crystals of a magnesium complex of the proline-functionalised calix[4]arene gelator.

An azobenzene-based photoswitchable crystal growth modifier

An azobenzene derivative reversibly switches to a less effective crystal growth modifier of calcite when irradiated by UV light.

Practice of pathological examinations in stillbirths: A 10-year retrospective study

OBJECTIVES

To describe the practice of fetal and placental pathological examinations in a large series of spontaneous stillbirths over 10 years.

MATERIALS AND METHODS

Inclusion of cases recorded by the Lower Normandy Regional Fetal-Infant Mortality Observatory (observatoire régional de mortalité fœto-infantile) from January 1, 2005 to December 31, 2014. The possible cause of death was coded in accordance with the ReCoDe classification system.

RESULTS

Seven hundred and forty-four cases were recorded. The placental examinations were conducted in 93.7% of cases (CI_95%[91.7-95.3]), increasing over the study period, and an autopsy was proposed in 87.2% of cases (CI_95%[84.8-89.6]). Autopsy was conducted less frequently during the most recent period, with parental refusal increasing over time. In multivariate analysis, no factor was associated with a higher frequency of placental examinations, while autopsy was proposed more often under certain circumstances: less than 4 pregnancies (P<10^-2), birth weight from 1000 to 1500 grams (P=0.05), singleton (P<10^-2), clinical context not suggesting a cause (P<10^-3), type 1 or 2 maternity ward (P<10^-2), antepartum death (P<10^-3).

CONCLUSION

Placental analysis was almost systematically realized, as suggested by international guidelines. Fetal autopsy was often performed, however only in some specific circumstances. New practice guidance to realize customized fetal autopsies appear to be necessary.

Explorations of Cooperation and Recalcitrance in Secure Mental Health Hospitals

This paper reports on the findings of three qualitative research studies undertaken within, respectively, medium and low secure units in one UK region, and a high secure mental health hospital in England (UK). The first study investigated alliance based involvement practices. The second explored service user and staff views and sense making of the notion of recovery. The third study is ongoing into service user and staff experiences of extreme coercive measures, such as forms of restraint and long-term seclusion or segregation. All studies utilised either semi-structured interviews or focus groups. All data was subject to thematic analysis.

Selected and emergent themes include:

– the importance of relationships and communication; security first; involvement as pacification;

– different understandings of recovery; the importance of meaningful occupation; staff-service user relationships; recovery journeys and dialogue with the past; and recovery as personal responsibility;

– good and bad coercion; cooperation, resistance and recalcitrance; and alternatives to coercion.

Findings suggest that cooperation is largely framed by services in terms of compliance with a bio-medical model. The impact of the secure environment, whilst ever-present, is not an absolute constraint on the realisation of recovery or involvement objectives. The availability of extreme coercive measures raises some seemingly paradoxical understandings from both service user and staff perspectives. Critical social theory is drawn on to illuminate the tensions between cooperation and recalcitrance and suggest further exploration of their respective legitimacy.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Investigating hydrogel formation using in situ variable-temperature scanning probe microscopy

The assembly and disassembly of fibres formed by a low molecular weight hydrogelator are imaged at high resolution.

The assembly and disassembly of supramolecular gel fibres are observed in situ using variable temperature scanning probe microscopy. The results show that fibre formation can be monitored at high resolution at a surface, and the final fibre morphologies are broadly consistent with those found by ex situ analysis of the bulk gel. The impact of a gelation inhibitor upon the fibre morphology is successfully investigated, providing direct evidence for the mechanism of inhibition as a function of additive concentration.

The many roles of mellitic acid during barium sulfate crystallization

The various roles of mellitic acid during barium sulfate crystallization from nucleation to mesocrystal formation are explored and elucidated.

Tetrazoles: calcium oxalate crystal growth modifiers

Metabolically stable tetrazole molecules are shown to impact calcium oxalate crystallization, thus tetrazoles can be used in investigating biological crystallization processes.

Advanced bile acid-based multi-compartmental microencapsulated pancreatic β-cells integrating a polyelectrolyte-bile acid formulation, for diabetes treatment

This study utilized the Seahorse Analyzer to examine the effect of the bile acid ursodeoxycholic acid (UDCA), on the morphology, swelling, stability, and size of novel microencapsulated β-cells, in real-time. UDCA was conjugated with fluorescent compounds, and its partitioning within the microcapsules was examined using confocal microscopy. UDCA produced microcapsules with good morphology, better mechanical strength (p < 0.01), and reduced swelling properties (p < 0.01), but lower cell viability (p < 0.05) and cell count per microcapsule (p < 0.01). UDCA reduced the cells' biochemical activities, mitochondrial respiration, and energy production, post-microencapsulation. This is the first time biological functions of microencapsulated β-cells have been analyzed in real-time.

[Failure of vacuum extractions: risk factors, maternal and fetal issues]

OBJECTIVES

Determine cases which are at risk of vacuum extraction failure as well as maternal and foetal issues depending on the delivery outcome.

MATERIAL AND METHODS

It was a retrospective study comparing 147 vacuum failures, from January 2002 to December 2010, with a control group randomly composed of 526 successful vacuum extractions. The outcomes were high risk situations of vacuum failure, maternal and neonatal morbidity depending on the delivery method (caesarean section or other instrumental extraction).

RESULTS

The global vacuum failure rate was 3.3 %. During labour, we identified several situations at risk of vacuum extraction failure: cephalhematomas prior to extraction (P<0.001), deflexion attitude (P<0.001), posterior variety (P<0.001), entering above the inlet strait (P<0.001), occiput posterior delivery (P<0.001), fœtal weight greater than 3500g (P=0.023). Neonatals consequency were more Apgar score below 7 at five minutes life (P=0.007), fœtal acidosis (pH<7,20) (P=0.032), neonatal resuscitation (P<0.001), and craniofacial damages (P<0.001).

CONCLUSION

Many dystocic situations occurring during labour require intense care when practicing vacuum extraction since they more frequently result in failure. In case of vacuum extraction failure, immediate adaptation to extra-uterine life seems to be more difficult for new-born babies.

Self-management: is it time for a new direction in rehabilitation and post stroke care?

Stroke is traditionally thought of as an acute condition and most rehabilitation is provided in the first six months poststroke. To date there has been minimal focus on strategies which could support people in the longer term and manage the transition towards successful adjustment and self-management. Stroke self-management programs whilst rare are now starting to emerge but while the feasibility and acceptability of delivering stroke self-management programs looks to be promising, there are minimal findings beyond phase II trials. A self-management program is a complex intervention and a carefully staged approach to research is required, one which addresses the issues around implementation and the skills required by those delivering the intervention. In addition there are a number of questions relating to maintenance of self-management skills beyond attendance at programs or after rehabilitation. Currently the sustainability of any impact from these programs is uncertain and it is unclear which are the best methods to enhance self-management skills over a longer time period. More work is required in order to develop and test different forms of support which could range from a simple goal setting interventions to more structured self-management programs delivered either as a group or individualized intervention.

Placement of combat stress teams in Afghanistan: reducing barriers to care

This article describes the medical planning process whereby combat stress and mental health clinicians were placed at Forward Operating Bases in southern and western Afghanistan during a period of intensive surge operations in 2009-2010. The distribution plan for the Combat Stress Control teams was based on previously published guidance on ratios of combat stress personnel to troop end-strength, population at-risk data, and kinetic activity associated with current and future combat operations. The article concludes with outcome data that validates the distribution decisions made through the planning process. Through dissemination of this information, it is hoped that future planners and clinicians can improve the processes involved in providing combat stress and mental health services to forward-deployed troops.

A new scheme for stigmatic x-ray imaging with large magnification

This paper describes a new x-ray scheme for stigmatic imaging. The scheme consists of one convex spherically bent crystal and one concave spherically bent crystal. The radii of curvature and Bragg reflecting lattice planes of the two crystals are properly matched to eliminate the astigmatism, so that the conditions for stigmatic imaging are met for a particular wavelength. The magnification is adjustable and solely a function of the two Bragg angles or angles of incidence. Although the choice of Bragg angles is constrained by the availability of crystals, this is not a severe limitation for the imaging of plasmas, since a particular wavelength can be selected from the bremsstrahlung continuum. The working principle of this imaging scheme has been verified with visible light. Further tests with x rays are planned for the near future.

Campylobacter antimicrobial resistance in Peru: a ten-year observational study

Background

Campylobacter jejuni and Campylobacter coli are food-borne pathogens of great importance and feature prominently in the etiology of developing world enteritis and travellers’ diarrhoea. Increasing antimicrobial resistant Campylobacter prevalence has been described globally, yet data from Peru is limited. Our objective was to describe the prevalence trends of fluoroquinolone and macrolide-resistant C. jejuni and C. coli stool isolates from three regions in Peru over a ten-year period.

Methods

Surveillance for enteric pathogens was conducted in Lima, Iquitos and Cusco between 2001 and 2010. Campylobacter stool isolates were tested for susceptibilities to ciprofloxacin, azithromycin and erythromycin. Susceptibilities were reviewed for 4652 isolates from Lima ( n = 3419), Iquitos ( n = 625) and Cusco ( n = 608).

Results

Comparing the study periods of 2001-2005 and 2006-2010, prevalence of ciprofloxacin-resistant C. jejuni isolates rose in the study areas of Lima (73.1% to 89.8%, p < 0.001) and Iquitos (24.1% to 48.9%, p < 0.001). Ciprofloxacin-resistant C. coli rates also increased in Lima (48.1% to 87.4%, p < 0.001) and Cusco (10.0% to 65.9%, p = 0.005). Small but significant increases in azithromycin-resistant and erythromycin-resistant C. jejuni prevalence were noted in Iquitos (2.2% to 14.9%, p < 0.001; 3.2% to 14.9%, p = 0.002), and erythromycin-resistant C. coli rates increased in Lima (0.0% to 5.3%, p = 0.038). The prevalence of C. jejuni isolates resistant to both ciprofloxacin and azithromycin increased in Iquitos (0.3% to 14.9%, p < 0.001) and Lima (0.3% to 1.6%, p = 0.011), and prevalence of C. jejuni isolates resistant to both ciprofloxacin and erythromycin rose in Iquitos (0.0% to 14.9%, p < 0.001). Ciprofloxacin and erythromycin resistant C. coli prevalence increased in Lima (0.0% to 5.3%, p = 0.034).

Conclusions

These results have implications for the empirical management of enterocolitis in Peru. Ongoing surveillance is essential to guide appropriate antimicrobial use in this setting. Local epidemiological studies to explore the relationship between increasing antimicrobial resistance and agricultural or human antibiotic use may be valuable.