Use of Cefiderocol in the Management of Children With Infection or Colonization With Multi-drug Resistant Gram-negative Bacteria: A Retrospective, Single-center Case Series

Cefiderocol, a novel siderophore cephalosporin, represents a treatment option for infections with multidrug-resistant Gram-negative bacteria, of which rates are rising worldwide. Clinical data on its use in children is limited. In our pediatric case series, the largest reported to date, cefiderocol seems safe and well tolerated, with more favorable clinical outcomes when compared to the literature reviewing adult cases.

Novel Organism Verification and Analysis (NOVA) study: identification of 35 clinical isolates representing potentially novel bacterial taxa using a pipeline based on whole genome sequencing

BACKGROUND

Reliable species identification of cultured isolates is essential in clinical bacteriology. We established a new study algorithm named NOVA - Novel Organism Verification and Analysis to systematically analyze bacterial isolates that cannot be characterized by conventional identification procedures MALDI-TOF MS and partial 16 S rRNA gene sequencing using Whole Genome Sequencing (WGS).

RESULTS

We identified a total of 35 bacterial strains that represent potentially novel species. Corynebacterium sp. (n = 6) and Schaalia sp. (n = 5) were the predominant genera. Two strains each were identified within the genera Anaerococcus, Clostridium, Desulfovibrio, and Peptoniphilus, and one new species was detected within Citrobacter, Dermabacter, Helcococcus, Lancefieldella, Neisseria, Ochrobactrum (Brucella), Paenibacillus, Pantoea, Porphyromonas, Pseudoclavibacter, Pseudomonas, Psychrobacter, Pusillimonas, Rothia, Sneathia, and Tessaracoccus. Twenty-seven of 35 strains were isolated from deep tissue specimens or blood cultures. Seven out of 35 isolated strains identified were clinically relevant. In addition, 26 bacterial strains that could only be identified at the species level using WGS analysis, were mainly organisms that have been identified/classified very recently.

CONCLUSION

Our new algorithm proved to be a powerful tool for detection and identification of novel bacterial organisms. Publicly available clinical and genomic data may help to better understand their clinical and ecological role. Our identification of 35 novel strains, 7 of which appear to be clinically relevant, shows the wide range of undescribed pathogens yet to define.

Home visits to identify the roles lifestyle and stress play in families of children with obesity

One-sixth of Swiss children are affected by overweight, and despite the implementation of an evidence-based multiprofessional approach, there has only been moderate therapeutic success. An unfavourable home environment and psychosocial stresses on the family may impede lifestyle changes. This longitudinal observational study included children with obesity (body mass index [BMI] ≥97th percentile [P.]) or overweight (BMI ≥ 90th P.) with a comorbidity, and who were participating in a regional 12-month multiprofessional group programme (MGP). Two health professionals routinely visited the family home at baseline (T0) to identify obesogenic environmental factors and psychosocial stress using an observation and question checklist and the Heidelberger stress scale (HSS). At T0 and after an 8-month intensive intervention phase (T1), the BMI standard deviation score (BMI-SDS) and its associations with the environmental and psychosocial factors were assessed. Twenty-eight children (17 male) met the criteria for participation in the MGP. At T0, age was 11.2 ± 1.71 years, BMI 28.1 ± 4.7 kg/m2 and BMI-SDS 2.9 ± 0.8, means ±SD. By T1, the mean BMI-SDS had decreased significantly, by -0.11 (p < .05). The stress scores (30.46 ± 17.8) were elevated and the subcategories of financial and social stress showed a trend towards predicting BMI or BMI-SDS at T0 and T1, but none of the other supposed obesogenic risk factors significantly predicted weight status. Conducting home visits allowed health professionals to identify obesity-promoting home conditions and, more importantly, otherwise undisclosed high psychosocial stress and resource limitations in families that impacted the children's obesity before and after the MGP intervention.

Association between perioperative prophylaxis with cefuroxime plus metronidazole or amoxicillin/clavulanic acid and surgical site infections in paediatric uncomplicated appendectomy: a Swiss retrospective cohort study

OBJECTIVE

We aimed to evaluate the association between post-appendectomy SSI rates and the two most commonly used regimens for perioperative antimicrobial prophylaxis in Swiss children.

METHODS

We conducted a retrospective cohort study, analysing data from the Swiss national SSI surveillance database with a study period from 2014 to 2018. All hospitals undertaking paediatric appendectomies in Switzerland participate in the surveillance. We compared the cumulative incidence and odds of post-appendectomy SSI within 30 days of surgery in children ≤ 16 years of age undergoing appendectomy for uncomplicated appendicitis and receiving perioperative antimicrobial prophylaxis with cefuroxime plus metronidazole or with amoxicillin/clavulanic acid using multivariable adjusted logistic regression and propensity-score matching.

RESULTS

A total of 6207 cases were recorded in the study time frame. Overall SSI cumulative incidence was 1.9% (n = 119). 4256 children (54.9% male, median (IQR) age 12 [10, 14] years) received either cefuroxime plus metronidazole (n = 2348, 53.8% male) or amoxicillin/clavulanic acid (n = 1491, 57.0% male). SSI cumulative incidence was 1.1% (25/2348) among children receiving cefuroxime plus metronidazole and 2.8% (42/1491, p < 0.001) when receiving amoxicillin/clavulanic acid. The administration of cefuroxime plus metronidazole was associated with statistically significantly lower SSI odds compared to amoxicillin/clavulanic acid (aOR 0.35, 95%CI [0.20, 0.61], p < 0.001), and this was confirmed upon propensity-score matching.

CONCLUSION

We found lower odds of post-appendectomy SSI in children receiving cefuroxime plus metronidazole compared to amoxicillin/clavulanic acid. Treating amoxicillin/clavulanic acid as the baseline, only 55 children need to receive cefuroxime plus metronidazole perioperative prophylaxis to avert one SSI. Existing guidelines recommending amoxicillin/clavulanic acid may need to be revised. Trial registration ISRCTN47727811, registered retrospectively.

MIS-C-Implications for the Pediatric Surgeon: An Algorithm for Differential Diagnostic Considerations

BACKGROUND

multisystem inflammatory syndrome in children (MIS-C) is a new disease associated with a recent infection with severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). Affected children can present predominantly with abdominal symptoms, fever and high inflammatory parameters that might lead to a consult by the pediatric surgeon and an indication for surgery.

METHODS

clinical data of three patients with MIS-C that underwent surgery were collected. Histopathological analysis of the appendix was performed.

RESULTS

we present the clinical course of three children with fever, abdominal pain and vomiting for several days. Clinical examination and highly elevated inflammation markers led to indication for laparoscopy; appendectomy was performed in two patients. Because of intraoperative findings or due to lack of postoperative improvement, all patients were reevaluated and tested positive for MIS-C associated laboratory parameters and were subsequently treated with corticosteroids, intravenous immunoglobulins, acetyl salicylic acid and/or light molecular weight heparin.

CONCLUSIONS

we discuss the implications of MIS-C as a new differential diagnosis and stress the importance of assessing the previous medical history, identifying patterns of symptoms and critically surveilling the clinical course. We implemented an algorithm for pediatric surgeons to consider MIS-C as a differential diagnosis for acute abdomen that can be integrated into the surgical workflow.

Posttreatment Lyme Disease Syndrome-What It Might Be and What It Is Not

Lyme disease is a multisystem disease caused by Borrelia burgdorferi infection and accounts for well-defined manifestations, appearing either at an early or late stage. Appropriate antibiotic therapy generally leads to a favorable outcome. Still, unspecific persisting symptoms such as fatigue, myalgia, arthralgia or cognitive dysfunction are reported by several patients months to years after adequate treatment. Their underlying pathophysiologic mechanism is unclear. However, there is no evidence for microbiological persistence in these cases and attempts to resolve the symptoms by repeated or prolonged antibiotic treatment have not been convincingly successful, but they may rather be harmful. To narrow down the controversially handled entity of posttreatment Lyme disease syndrome (PTLDS) and to avoid overdiagnosis and overtreatment, case definitions have been proposed, acknowledging PTLDS as a complex of nonspecific, subjective symptoms, which are neither caused by ongoing infection nor by any other identifiable disease. PTLDS is mainly a diagnosis of exclusion and requires careful evaluation of differential diagnosis followed by counseling about optimal management in light of missing specific therapeutic options.

X-Linked Lymphoproliferative Disease Mimicking Multisystem Inflammatory Syndrome in Children-A Case Report

Most children with a SARS-CoV-2 infection are asymptomatic or exhibit mild symptoms. However, a small number of children develop features of substantial inflammation temporarily related to the COVID-19 also called multisystem inflammatory syndrome in children (MIS-C) or pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS), clinically similar to Kawasaki disease, toxic shock syndrome and hemophagocytic lymphohistiocytosis (HLH). It is well-known that genetic pre-disposition plays an important role in virally-triggered diseases such as Epstein-Barr virus (EBV)-associated HLH, while this has not yet been established for patients with MIS-C. Here we describe a male patient fulfilling the diagnostic criteria of MIS-C, who was initially treated according to current consensus guidelines. Presence of hypofibrinogenemia, normal lymphocyte counts and C-reactive protein, but substantial hyperferritinemia distinguish this patient from others with MIS-C. The clinical course following initial presentation with acute respiratory distress syndrome was marked by fatal liver failure in the context of EBV-associated HLH despite treatment with steroids, intravenous immunoglobulins, interleukin (IL)-1 receptor blockade and eventually HLH-directed treatment. X-linked lymphoproliferative disease type 1 (XLP1), a subtype of primary HLH was diagnosed in this patient post-mortem. This case report highlights the importance of including HLH in the differential diagnosis in MIS-C with severe disease course to allow specific, risk-adapted treatment and genetic counseling.

AB0029 INHIBITION OF EFFECTOR B CELLS BY IBRUTINIB IN SYSTEMIC SCLEROSIS

Background:

Systemic sclerosis (SSc) is a connective tissue disease with significant morbidity and mortality. Effective treatment is still missing, and clinical control of the disease remains challenging. In particular, the development of pulmonary and cardiac fibrosis and pulmonary hypertension are severe complications responsible for excessive mortality. Currently available treatment strategies – besides aggressive autologous stem cell transplantation which is an option only for selected patients – only alleviate symptoms and slow disease progression. Previous attempts of immunomodulating therapies addressing B cell pathology like rituximab and tocilizumab in SSc showed mixed efficacy1,2

Objectives:

Here, we investigated the therapeutic potential of ibrutinib, a Bruton’s tyrosine kinase (BTK) inhibitor used in B cell malignancies, to alter B cell pathology in SSc in anin vitromodel of autoimmunity.

Methods:

PBMCs and sorted B cells of 24 patients with SSc were used for functional testing after stimulation with hypomethylated DNA fragments (CpG) to induce an innate immune response. The effects of ibrutinib on cytokine production, autoantibody release and activation of the transcription factor NFκB were evaluated via multiplex cytokine assay, ELISA and flow cytometry.

Results:

Ibrutinib was able to reduce the production of the profibrotic hallmark cytokines IL-6 and TNF-α, which are mainly released by the effector B cell population, in response to TLR9-stimulation. Importantly, small doses of ibrutinib (0.1 µM) preserved the production of immunoregulatory IL-10 and IFN-γ while effectively inhibiting the cardinal cytokines of hyperactivated profibrotic effector B cells in SSc. Intracellular cytokine staining of IL-6 in B cell subsets further endorsed the potential of ibrutinib to inhibit B cells in a subset-specific manner, reducing IL-6+naïve B cells significantly but not IL-6+memory B cells. The subset specificity was abolished when high doses of ibrutinib (10 µM) were applied. In a flow cytometry analysis of phosphorylated NFκB, an important transcription factor in the induction of innate immune responses in B cells, significantly less activation was observed with ibrutinib treatment (0.1 µM). Higher doses of ibrutinib were unable to further reduce the abundance of pNFκB.

Conclusion:

Our data could pave the avenue for a clinical application of ibrutinib for patients with SSc as a novel treatment option for the underlying pathogenetic immune imbalance contributing to disease onset and progression.

References:

[1]Khanna, D.et al.Efficacy and Safety of Tocilizumab for the Treatment of Systemic Sclerosis: Results from a Phase 3 Randomized Controlled Trial [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 10).

[2]Jordan, S.et al.Effects and safety of rituximab in systemic sclerosis: an analysis from the European Scleroderma Trial and Research (EUSTAR) group.Ann. Rheum. Dis.74, 1188–1194 (2015).

Disclosure of Interests:

Jakob Einhaus: None declared, Ann-Christin Pecher: None declared, Elisa Asteriti: None declared, Hannes Schmid: None declared, Kathy-Ann Secker: None declared, Silke Duerr-Stoerzer: None declared, Hildegard Keppeler: None declared, Reinhild Klein: None declared, Corina Schneidawind: None declared, Jörg Henes Grant/research support from: Novartis, Roche-Chugai, Consultant of: Novartis, Roche, Celgene, Pfizer, Abbvie, Sanofi, Boehringer-Ingelheim,, Dominik Schneidawind: None declared

Development and external validation study of a melanoma risk prediction model incorporating clinically assessed naevi and solar lentigines

BACKGROUND

Melanoma risk prediction models could be useful for matching preventive interventions to patients' risk.

OBJECTIVES

To develop and validate a model for incident first-primary cutaneous melanoma using clinically assessed risk factors.

METHODS

We used unconditional logistic regression with backward selection from the Australian Melanoma Family Study (461 cases and 329 controls) in which age, sex and city of recruitment were kept in each step, and we externally validated it using the Leeds Melanoma Case-Control Study (960 cases and 513 controls). Candidate predictors included clinically assessed whole-body naevi and solar lentigines, and self-assessed pigmentation phenotype, sun exposure, family history and history of keratinocyte cancer. We evaluated the predictive strength and discrimination of the model risk factors using odds per age- and sex-adjusted SD (OPERA) and the area under curve (AUC), and calibration using the Hosmer-Lemeshow test.

RESULTS

The final model included the number of naevi ≥ 2 mm in diameter on the whole body, solar lentigines on the upper back (a six-level scale), hair colour at age 18 years and personal history of keratinocyte cancer. Naevi was the strongest risk factor; the OPERA was 3·51 [95% confidence interval (CI) 2·71-4·54] in the Australian study and 2·56 (95% CI 2·23-2·95) in the Leeds study. The AUC was 0·79 (95% CI 0·76-0·83) in the Australian study and 0·73 (95% CI 0·70-0·75) in the Leeds study. The Hosmer-Lemeshow test P-value was 0·30 in the Australian study and < 0·001 in the Leeds study.

CONCLUSIONS

This model had good discrimination and could be used by clinicians to stratify patients by melanoma risk for the targeting of preventive interventions. What's already known about this topic? Melanoma risk prediction models may be useful in prevention by tailoring interventions to personalized risk levels. For reasons of feasibility, time and cost many melanoma prediction models use self-assessed risk factors. However, individuals tend to underestimate their naevus numbers. What does this study add? We present a melanoma risk prediction model, which includes clinically-assessed whole-body naevi and solar lentigines, and self-assessed risk factors including pigmentation phenotype and history of keratinocyte cancer. This model performs well on discrimination, the model's ability to distinguish between individuals with and without melanoma, and may assist clinicians to stratify patients by melanoma risk for targeted preventive interventions.

Associations of pigmentary and naevus phenotype with melanoma risk in two populations with comparable ancestry but contrasting levels of ambient sun exposure

BACKGROUND

People at high risk of developing melanoma are usually identified by pigmentary and naevus phenotypes.

OBJECTIVE

We examined whether associations of these phenotypes with melanoma risk differed by ambient sun exposure or participant characteristics in two population-based, case-control studies with comparable ancestry but different ambient sun exposure.

METHODS

Data were analysed from 616 cases and 496 controls from the Australian Melanoma Family Study and 2012 cases and 504 controls from the Leeds (UK) case-control study. Questionnaire, interview and dermatological skin examination data were collected using the same measurement protocols. Relative risks were estimated as odds ratios using unconditional logistic regression, adjusted for potential confounders.

RESULTS

Hair and skin colour were the strongest pigmentary phenotype risk factors. All associations of pigmentary phenotype with melanoma risk were similar across countries. The median number of clinically assessed naevi was approximately three times higher in Australia than Leeds, but the relative risks for melanoma associated with each additional common or dysplastic naevus were higher for Leeds than Australia, especially for naevi on the upper and lower limbs. Higher naevus counts on the head and neck were associated with a stronger relative risk for melanoma for women than men. The two countries had similar relative risks for melanoma based on self-reported naevus density categories, but personal perceptions of naevus number differed by country. There was no consistent evidence of interactions between phenotypes on risk.

CONCLUSIONS

Classifying people at high risk of melanoma based on their number of naevi should ideally take into account their country of residence, type of counts (clinical or self-reported), body site on which the naevus counts are measured and sex. The presence of naevi may be a stronger indicator of a genetic predisposition in the UK than in Australia based on less opportunity for sun exposure to influence naevus development.

III-V heterostructure tunnel field-effect transistor

The tunnel field-effect transistor (TFET) is regarded as one of the most promising solid-state switches to overcome the power dissipation challenge in ultra-low power integrated circuits. TFETs take advantage of quantum mechanical tunneling hence exploit a different current control mechanism compared to standard MOSFETs. In this review, we describe state-of-the-art development of TFET both in terms of performances and of materials integration and we identify the main remaining technological challenges such as heterojunction defects and oxide/channel interface traps causing trap-assisted-tunneling (TAT). Mesa-structures, planar as well as vertical geometries are examined. Conductance slope analysis on InAs/GaSb nanowire tunnel diodes are reported, these two-terminal measurements can be relevant to investigate the tunneling behavior. A special focus is dedicated to III-V heterostructure TFET, as different groups have recently shown encouraging results achieving the predicted sub-thermionic low-voltage operation.

Structure and chemistry of interfaces between ceria and yttria-stabilized zirconia studied by analytical STEM

Epitaxial undoped and Gd₂O₃-doped ceria films were grown by pulsed laser deposition on (1 1 1) faced Y₂O₃-stabilized zirconia (YSZ). Highly localized cerium reduction at the film-substrate interfaces is revealed by atomically resolved valence EELS mapping using C_s aberration-corrected scanning transmission electron microscopy. The chemical profiles reveal interdiffusion of Ce, (Gd), Y, Zr, forming an intermixing zone at the interface 7-9 (1 1 1) lattice planes wide. In its vicinity, the fraction of Ce³⁺ raises gradually over 6-8 lattice planes from zero in the bulk ceria to ≈100% in one single plane at the interface. Beyond this plane the Ce³⁺ fraction drops sharply within the YSZ substrate. In the vicinity of the interface systematic scan deflections are observed during EELS line scans. The advancing electron probe experiences a retarding force at the ceria side, and an accelerating force at the YSZ side, irrespective of the scan direction. This behavior is suggestive of coulombic interactions between the electron probe and a charged interface. This is interpreted as an indication of the presence of a space-charge situation at the YSZ/ceria interface, resulting from an excess negative charge at the ceria side (due to Ce³⁺cations) and an excess positive charge at the YSZ side (due to oxygen vacancies).

Unsteady walking as a symptom in type 2 diabetes mellitus: independent association with depression and sedentary lifestyle and no association with diabetic neuropathy

The purpose of this study was to look at the determinants of the unsteady walking (UW) symptom in patients with type 2 diabetes mellitus (T2DM) by defining if UW and/or the Diabetic Neuropathy Symptoms Score (DNSS) are associated with positive scores in Beck's Depression Inventory (BDI) and with a positive Michigan Neuropathy Screening Instrument score (MNSI). We evaluated 203 T2DM patients without visible gait disturbances. They were divided into UW (+) and UW (−) or DNSS (+) and DNSS (−) according to symptoms. We found a prevalence of 48.3% for UW (+) and of 63% for DNSS (+) in our sample. In univariate analysis, the presence of UW was significantly associated with waist circumference (P=0.024), number of comorbidities (P=0.012), not practicing physical exercise (P=0.011), positive BDI score (P=0.003), presence of neuropathic symptoms by the MNSI questionnaire (P<0.001), and positive diabetic neuropathy screening by MNSI (P=0.021). In multivariate analysis, UW (used as a dependent variable) was independently associated with a positive BDI score (P<0.001; 95%CI=1.01-1.03), T2DM duration (P=0.023; 95%CI=1.00–1.03), number of co-morbidities (P=0.032; 95%CI=1.01–1.37), and a sedentary lifestyle (P=0.025; 95%CI=1.06–2.5). The UW symptom and a positive DNSS are more closely related to a positive score for depression than to presence of neuropathy in T2DM.

[Marginal protection of retinal cells by bisperoxovanadium : Appropriate therapy in the model of retinal ischemia?]

BACKGROUND

Ischemic processes usually lead to the destruction of retinal cells and therefore play a key role in a multitude of eye diseases.

OBJECTIVE

The aim of this study was to investigate whether bisperoxovanadium has a potential neuroprotective effect in an ischemia/reperfusion animal model.

MATERIAL AND METHODS

Initially, ischemia was induced in one eye of an ischemia/reperfusion model and 3 days later, a 14-day medication-based treatment was initiated. Bisperoxovanadium was administered intraperitoneally every 3 days. Subsequently, the number of ganglion cells, the rate of apoptosis, amacrine cells, macroglia, microglia, and their activation state, as well as photoreceptors were determined by histological and immunohistochemical analyses.

RESULTS

In comparison to the control group, a significant retinal ganglion cell loss, a significant reduction of the inner layers as well as a decrease in photoreceptor and amacrine cell numbers could be determined in the ischemic eyes. In addition, there was an increase in the number of microglia in these animals. The rats treated with bisperoxovanadium did not exhibit a significant neuroprotective effect regarding the number of ganglion cells, the rate of apoptosis, macroglia, amacrine cells, or photoreceptors; however, a low structural degeneration of photoreceptors could be observed as an effect of the treatment. Additionally, fewer microglia and activated microglia were observed after bisperoxovanadium treatment.

CONCLUSION

Bisperoxovanadium seems to have only a marginal neuroprotective effect on ischemic retinae. It needs to be examined whether earlier therapy onset, higher dose or different route of administration would significantly improve the results or whether this therapeutic approach is unsuitable.

Manipulating Surface States of III-V Nanowires with Uniaxial Stress

III-V compound semiconductors are indispensable materials for today's high-end electronic and optoelectronic devices and are being explored for next-generation transistor logic and quantum technologies. III-V surfaces and interfaces play the leading role in determining device performance, and therefore, methods to control their electronic properties have been developed. Typically, surface passivation studies demonstrated how to limit the density of surface states. Strain has been widely used to improve the electronic transport properties and optoelectronic properties of III-Vs, but the potential of this technology to modify the surface properties still remains to be explored. Here we show that uniaxial stress induces a shift in the energy of the surface states of III-V nanowires, modifying their electronic properties. We demonstrate this phenomenon by modulating the conductivity of InAs nanowires over 4 orders of magnitude with axial strain ranging between -2.5% in compression and 2.1% in tension. The band bending at the surface of the nanostructure is modified from accumulation to depletion reversibly and reproducibly. We provide evidence of this physical effect using a combination of electrical transport measurement, Raman spectroscopy, band-structure modeling, and technology computer aided design (TCAD) simulations. With this methodology, the deformation potentials for the surface states are quantified. These results reveal that strain technology can be used to shift surface states away from energy ranges in which device performance is negatively affected and represent a novel route to engineer the electronic properties of III-V devices.

Association of daptomycin use with resistance development in Enterococcus faecium bacteraemia-a 7-year individual and population-based analysis

OBJECTIVE

In this study we aimed to analyse the association between use of daptomycin and MICs of daptomycin in Enterococcus faecium bacteraemia.

METHODS

We prospectively enrolled patients aged ≥18 years with E. faecium bacteraemia hospitalized at the University Hospital Basel from 2008 to 2014. We determined daptomycin MICs by Etests and used pulsed field gel electrophoresis to determine clonal relatedness. We recorded the defined daily dosages of daptomycin (DDDs) per 100 patient-days and clinical data from charts. We correlated daptomycin MIC with use of daptomycin in patients with recurrence/persistence.

RESULTS

In 195 E. faecium bacteraemias originating from 162 patients the median MIC for daptomycin was 2 mg/L (IQR 2-3); 30% (15.4%) isolates had a MIC ≥4 mg/L and 6 (3.1%) were resistant (MIC >4 mg/L) according to CLSI criteria. The usage of daptomycin increased more than four-fold from 0.36 DDDs/100 patient-days in 2008 to 1.6 in 2014. In 13 of 28 (42.9%) patients with a relapsing or persisting bacteraemia, the daptomycin MIC of the second isolate increased from a median of 2.0 to 2.5 mg/L (p 0.010); 3/13 (23.1%) developed resistance. All patients with the same clone in the first and second episode and an increase of daptomycin MIC had been treated with daptomycin (6/6 versus 1/7 p 0.005).

CONCLUSIONS

Daptomycin MICs and Daptomycin usage increased over time. On an individual patient level daptomycin exposure was associated with an increased MIC in subsequent bacteraemia episodes. Diversity did not indicate a clonal origin and argues for a de novo development of resistance.

Full thermoelectric characterization of InAs nanowires using MEMS heater/sensors

Precise measurements of a complete set of thermoelectric parameters on a single indium-arsenide nanowire (NW) have been performed using highly sensitive, micro-fabricated sensing devices based on the heater/sensor principle. The devices were fabricated as micro electro-mechanical systems consisting of silicon nitride membranes structured with resistive gold heaters/sensors. Preparation, operation and characterization of the devices are described in detail. Thermal decoupling of the heater/sensor platforms has been optimized reaching thermal conductances as low as 20 nW K(-1) with a measurements sensitivity below 20 nW K(-1). The InAs NWs were characterized in terms of thermal conductance, four-probe electrical conductance and thermopower (Seebeck coefficient), all measured on a single NW. The temperature dependence of the parameters determining the thermoelectric figure-of-merit of an InAs NW was acquired in the range 200-350 K featuring a minor decrease of the thermal conductivity from 2.7 W (m K)(-1) to 2.3 W (m K)(-1).

Defect structures in ZnO studied by high-resolution structural and spectroscopic imaging

The formation of characteristic inversion domain structures in zinc oxide (ZnO) is triggered by the addition of trivalent Fe(3+) or In(3+) dopants. As-grown and inverted ZnO domains are separated by two types of inversion domain boundaries (IDBs): basal b-IDBs parallel to {0001}, and pyramidal p-IDBs parallel to {21¯1¯5} lattice planes in three equivalent variants. Cs-corrected analytical TEM/STEM is the method of choice for a comprehensive structural and compositional characterization of these materials. It is shown by electron and X-ray spectroscopic imaging in STEM that dopant species are essentially localized within both types of IDBs, whereas solid solubility of trivalent dopants within ZnO domains is rather low (<0.5at%). Under the assumption of one monolayer per IDB the relation between inversion domain structure and integral dopant concentration correlates well with integral EDS and EELS measurements in STEM over well defined sample regions. The presence of one close-packed monolayer of trivalent dopant ions within a b-IDB is unambiguously confirmed by atomic resolution STEM imaging. Columns of cations are clearly imaged in high-angle annular dark-field (HAADF) STEM imaging, whereas annular bright-field (ABF) STEM is capable of imaging both light and heavy atom columns simultaneously. It is shown that structural details in ABF images are directly interpretable even in specimen regions with thickness >50nm. The structural inversion associated with a stacking fault as a consequence of the presence of octahedrally coordinated In(3+) in the b-IDB is directly revealed by atomic resolution imaging. Column positions in atomic resolution ABF imaging in In2O3-ZnO nanorods show that the oxygen sub-lattice continues across the b-IDB with only marginal distortions, whereas the cation sub-lattice suffers a rigid shift relative to the oxygen lattice as a result of the coordination geometry of ZnO4 tetrahedrons sharing common oxygen ions with the InO6 coordination octahedrons.

Leaching of metal(loid)s from a construction material: influence of the particle size, specific surface area and ionic strength

Construction materials are tested worldwide for a potential release of dangerous substances to prevent adverse effects on humans and biota. It is crucial to identify and understand the processes which are decisive for the release of hazardous substances. The current study compares the results of different test methods. Taking copper slag as model material, the influence of material particle size, eluant composition and ionic strength was tested. Ionic strength and salinity significantly influenced the release of metal(loid)s in the water phase. Furthermore, it was elucidated that colloids can cause methodological artefacts. The available specific surface area exhibited a positive correlation with the release of hazardous substances. The specific surface areas of materials were determined by the Brunauer, Emmett and Teller model (BET) and four other methods. The aluminium foil method showed the best results with regard to the statistical uncertainty, compared to a 3D laser scanning method. With help of the roughness factor λ it is possible to compare the results from surface area measurements with different material particle sizes (0-250 mm). This comparability offers the potential to match the release of metal(loid)s from laboratory studies with field applications and catchment area calculations/modelling, based on the release per m(2).

[Acute kidney injury]

Acute kidney injury plays a pivotal role in intensive care medicine and exerts crucial adverse effects on the course of the disease and overall prognosis of the critically ill patient. Intensive renal support, including initiation of earlier dialysis or maximal uremic toxin removal by higher dosage and frequency of renal replacement therapy, and individualized selection of modality were not able to decrease excessive mortality in this population. Systemic acute inflammation, mediated, at least in part, by cytokines, and not secondary uremic side effects, seems to have a major impact on nonrenal organ damage. Assessment of short-term outcome in critically ill patients who develop acute kidney injury may underestimate the true burden of disease. The overall survival at 5 years in patients discharged alive after severe acute kidney injury necessitating renal replacement therapy is only 20-30%, comparable to cancer patients. In addition, acute renal damage was identified as an independent risk factor for progression of chronic renal insufficiency. Current research focuses on strategies for the prevention of acute kidney injury and on the establishment of effective biomarkers for the early recognition and accurate diagnosis of subclinical renal damage.

Kidney-specific cadherin correlates with the ontogenetic origin of renal cell carcinoma subtypes: an indicator of a malignant potential?

INTRODUCTION AND OBJECTIVES

To evaluate retrospectively kidney-specific cadherin (Ksp-cad) expression in renal cell carcinoma (RCC) subtypes and oncocytoma in correlation with its ontogenetic origin of distal and proximal tubules and to correlate Ksp-cad expression with tumour characteristics.

MATERIALS AND METHODS

Membranous and cytoplasmic expression of Ksp-cad was determined in 40 clear cell (ccRCC), 25 papillary (pRCC), 19 chromophobe carcinomas (chRCC), 27 oncocytomas (oncocytomas) (n = 111) and 32 benign kidney parenchyma specimens separated in distal tubules (DT) and proximal tubules (PT) by immunohistochemistry using tissue microarray technique. Staining intensity was quantified as a score ranging from 0 to 12. Comparison of data and correlation with tumour characteristics were done by Wilcoxon/Kruskal-Wallis tests (post hoc Tukey-Kramer analysis).

RESULTS

In benign renal tissue, membranous and cytoplasmic expression of Ksp-cad in the DT was significantly higher than that in the PT (12.0 ± 0 vs. 5.2 ± 0.3 and 6.3 ± 0.5 vs. 0.0 ± 0.0, respectively; (P < 0.05)). Membranous KSP-cad expression was significantly higher in chRCC (5.2 ± 0.8) and oncocytomas (3.7 ± 0.4) than that in ccRCC (0.8 ± 0.2) and pRCC (1.4 ± 0.4; P < 0.05), while expression between oncocytomas and chRCC did not differ significantly. In RCC, Ksp-cad expression was significantly associated with higher T stage and the occurrence of synchronous metastasis (P < 0.05). Higher N stages and grading tended to correlate with a lower Ksp-cad expression.

CONCLUSIONS

In this cohort, the origin of tumour subtypes-chRCC and oncocytomas develop from DT and ccRCC and pRCC from PT cells-is mirrored by the respective Ksp-cad expression. This raises the question whether DT-derived tumours have a less malignant potential than PT-derived tumours.

Consistent formulation of the growth process at the kinematic and constitutive level for soft tissues composed of multiple constituents

Previous studies have investigated the possibilities of modelling the change in volume and change in density of biomaterials. This can be modelled at the constitutive or the kinematic level. This work introduces a consistent formulation at the kinematic and constitutive level for growth processes. Most biomaterials consist of many constituents and can be approximated as being incompressible. These two conditions (many constituents and incompressibility) suggest a straightforward implementation in the context of the finite element (FE) method which could now be validated more easily against histological measurements. Its key characteristic variable is the normalised partial mass change. Using the concept of homeostatic equilibrium, we suggest two complementary growth laws in which the evolution of the normalised partial mass change is governed by an ordinary differential equation in terms of either the Piola-Kirchhoff stress or the Green-Lagrange strain. We combine this approach with the classical incompatibility condition and illustrate its algorithmic implementation within a fully nonlinear FE approach. This approach is first illustrated for a simple uniaxial tension and extension test for pure volume change and pure density change and is validated against previous numerical results. Finally, a physiologically based example of a two-phase model is presented which is a combination of volume and density changes. It can be concluded that the effect of hyper-restoration may be due to the systemic effect of degradation and adaptation of given constituents.

The potential role of somatostatin analogues in the treatment of gastrointestinal (GI) cancers

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Background: Somatostatin receptors (sstr) are expressed in various normal and malignant tissues, including non-neuroendocrine GI solid tumors. Gastric cancer (GC) cells mainly express sstr2 and sstr5, colorectal cancer (CRC) cells predominantly express sstr1 followed by sstr5 and sstr2, and hepatocellular carcinoma (HCC) cells express mainly sstr5 as well as sstr1,2,3. Somatostatin analogues (SAs) may have direct and indirect antitumor activity. Octreotide and lanreotide primarily target sstr2, whereas the new agent pasireotide has high affinity for sstr1,2,3 and sstr5.

Methods: Published data evaluating the antitumor properties of SAs in GI tumors were reviewed.

Results: The table lists the results of clinical studies in which SAs were evaluated as antitumor therapies in GI cancers.

Conclusions: Although octreotide and lanreotide are efficacious in the treatment of symptoms of neuroendocrine tumors, these agents have demonstrated mixed results in the antitumor treatment of non-neuroendocrine GI tumors. Data suggesting potential favorable outcomes with SAs alone or in combination with other agents have been seen in solid tumors with predominant sstr2 expression such as GC. Novel SAs such as pasireotide may have improved antitumor effects in non-neuroendocrine solid tumors expressing multiple sstr compared with octreotide and lanreotide.

[Table: see text]

[Table: see text]