Elemental composition and material properties of radular teeth in the heterobranch snail Gastropteron rubrum (Mollusca, Gastropoda, Cephalaspidea) foraging on hard organisms

The molluscan feeding structure is the radula, a chitinous membrane with teeth, which are highly adapted to the food and the substrate to which the food is attached. In Polyplacophora and Patellogastropoda, the handling of hard ingesta can be facilitated by high content of chemical compounds containing Fe or Si in the tooth cusps. Other taxa, however, possess teeth that are less mineralized, even though animals have to avoid structural failure or high wear during feeding as well. Here, we investigated the gastropod Gastropteron rubrum, feeding on hard Foraminifera, diatoms and Porifera. Tooth morphologies and wear were documented by scanning electron microscopy and their mechanical properties were tested by nanoindentation. We determined that gradients of hard- and stiffness run along each tooth, decreasing from cusp to basis. We also found that inner lateral teeth were harder and stiffer than the outer ones. These findings allowed us to propose hypotheses about the radula-ingesta interaction. In search for the origins of the gradients, teeth were visualized using confocal laser scanning microscopy, to determine the degree of tanning, and analyzed with energy-dispersive X-ray spectroscopy, to test the elemental composition. We found that the mechanical gradients did not have their origins in the elemental content, as the teeth did not contain high proportions of metals or other minerals. This indicates that their origin might be the degree of tanning. However, in the tooth surfaces that interact with the ingesta high Si and Ca contents were determined, which is likely an adaptation to reduce wear.

"But not the music": psychopathic traits and difficulties recognising and resonating with the emotion in music

Recognising and responding appropriately to emotions is critical to adaptive psychological functioning. Psychopathic traits (e.g. callous, manipulative, impulsive, antisocial) are related to differences in recognition and response when emotion is conveyed through facial expressions and language. Use of emotional music stimuli represents a promising approach to improve our understanding of the specific emotion processing difficulties underlying psychopathic traits because it decouples recognition of emotion from cues directly conveyed by other people (e.g. facial signals). In Experiment 1, participants listened to clips of emotional music and identified the emotional content (Sample 1, N = 196) or reported on their feelings elicited by the music (Sample 2, N = 197). Participants accurately recognised (t(195) = 32.78, p < .001, d = 4.69) and reported feelings consistent with (t(196) = 7.84, p < .001, d = 1.12) the emotion conveyed in the music. However, psychopathic traits were associated with reduced emotion recognition accuracy (F(1, 191) = 19.39, p < .001) and reduced likelihood of feeling the emotion (F(1, 193) = 35.45, p < .001), particularly for fearful music. In Experiment 2, we replicated findings for broad difficulties with emotion recognition (Sample 3, N = 179) and emotional resonance (Sample 4, N = 199) associated with psychopathic traits. Results offer new insight into emotion recognition and response difficulties that are associated with psychopathic traits.

Coping with abrasive food: diverging composition of radular teeth in two Porifera-consuming nudibranch species (Mollusca, Gastropoda)

Molluscs forage with their radula, a chitinous membrane with teeth. Adaptations to hard or abrasive ingesta were well studied in Polyplacophora and Patellogastropoda, but for other taxa there are large gaps in knowledge. Here, we investigated the nudibranch gastropods Felimare picta and Doris pseudoargus, both of which feed on Porifera. Tooth morphologies were documented by scanning electron microscopy, and mechanical properties were tested by nanoindentation. We found that these parameters are rather similar in both species, indicating that teeth are similar in their function. To study the composition, teeth were visualized using confocal laser scanning microscopy (CLSM), to determine the degree of tanning, and analysed with energy-dispersive X-ray spectroscopy, to test the elemental composition. The emitted autofluorescence signal and the inorganic content differed between the species. This was especially prominent when studying the inner and outer tooth surfaces (leading and trailing edges). In F. picta, we detected high proportions of Si, whereas teeth of D. pseudoargus contained high amounts of Ca, which influenced the autofluorescence signal in CLSM. Employing nanoindentation, we determined high Young's modulus and hardness values for the leading edges of teeth, which relate to the Si and Ca content. This highlights that teeth with a similar morphology and mechanical properties can be mechanically enhanced via different chemical pathways in Nudibranchia.

Vertebral osteomyelitis is characterised by increased RANK/OPG and RANKL/OPG expression ratios in vertebral bodies and intervertebral discs

Vertebral osteomyelitis (VO) is an infection of the spine mainly caused by bacterial pathogens. The pathogenesis leading to destruction of intervertebral discs (IVDs) and adjacent vertebral bodies (VBs) is poorly described. The present study aimed at investigating the connection between infection and bone/disc metabolism in VO patients. 14 patients with VO (infection group) and 14 patients with burst fractures of the spine (fracture group; control) were included prospectively. Tissue biopsies from affected IVDs and adjacent VBs were analysed by RT-qPCR for mRNA-expression levels of 18 target genes including chemokines, adipokines and genes involved in bone metabolism. Most importantly, the receptor activator of NF-κB/osteoprotegerin (RANK/OPG) expression ratio was drastically elevated in both VBs and IVDs of the infection group. In parallel, expression of genes of the prostaglandin-E2-dependent prostanoid system was induced. Such genes regulate tissue degradation processes via the triad OPG/RANK/RANKL as well as via the chemokines IL-8 and CCL-20, whose expression was also found to be increased upon infection. The gene expression of the adipokine leptin, which promotes inflammatory tissue degradation, was higher in IVD tissue of the infection group, whereas the transcription of omentin and resistin genes, whose functions are largely unknown in the context of infectious diseases, was lower in infected VBs. In summary, similar expression patterns of pro-inflammatory cytokines and pro-osteoclastogenic factors were identified in VBs and IVDs of patients suffering from VO. This suggests that common immuno-metabolic pathways are involved in the mechanisms leading to tissue degradation in VBs and IVDs during VO.

Radular force performance of stylommatophoran gastropods (Mollusca) with distinct body masses

The forces exerted by the animal's food processing structures can be important parameters when studying trophic specializations to specific food spectra. Even though molluscs represent the second largest animal phylum, exhibiting an incredible biodiversity accompanied by the establishment of distinct ecological niches including the foraging on a variety of ingesta types, only few studies focused on the biomechanical performance of their feeding organs. To lay a keystone for future research in this direction, we investigated the in vivo forces exerted by the molluscan food gathering and processing structure, the radula, for five stylommatophoran species (Gastropoda). The chosen species and individuals have a similar radular morphology and motion, but as they represent different body mass classes, we were enabled to relate the forces to body mass. Radular forces were measured along two axes using force transducers which allowed us to correlate forces with the distinct phases of radular motion. A radular force quotient, AFQ = mean Absolute Force/bodymass^0.67, of 4.3 could be determined which can be used further for the prediction of forces generated in Gastropoda. Additionally, some specimens were dissected and the radular musculature mass as well as the radular mass and dimensions were documented. Our results depict the positive correlation between body mass, radular musculature mass, and exerted force. Additionally, it was clearly observed that the radular motion phases, exerting the highest forces during feeding, changed with regard to the ingesta size: all smaller gastropods rather approached the food by a horizontal, sawing-like radular motion leading to the consumption of rather small food particles, whereas larger gastropods rather pulled the ingesta in vertical direction by radula and jaw resulting in the tearing of larger pieces.

[99cmTc]Tc-PSMA-I&S-SPECT/CT: experience in prostate cancer imaging in an outpatient center

BACKGROUND

Prostate-specific membrane antigen (PSMA) SPECT imaging in prostate cancer (PCa) could be a valuable alternative in regions where access to PSMA-PET imaging is restricted. [99mTc]Tc-PSMA-I&S is a new 99mTc-labeled PSMA-targeting SPECT agent, initially developed for radio-guided surgery. We report on the diagnostic use of [99mTc]Tc-PSMA-I&S-SPECT/CT in PCa.

RESULTS

[99mTc]Tc-PSMA-I&S-SPECT/CT was performed and evaluated in 210 outpatients with PCa at a single center. Patients were imaged for biochemical recurrence (BCR, n = 152, mean PSA 8.7 ng/ml), for primary staging of high-risk PCa (n = 12, mean PSA 393 ng/ml), and restaging in advanced recurrent PCa (n = 46, mean PSA 101.3 ng/ml). Number and location of positive lesions were determined for the different subgroups. For BCR, detection rates were calculated, defined as the proportion of scans with at least one PSMA-positive lesion. PSMA positive lesions were detected in 65.2% of all 210 patients. Tumor tissue was mainly detected in lymph nodes (59%), in the bone (42%), and in the prostate (fossa) (28%). In the subgroup of patients referred for detection of BCR the detection rate increased from 20% at a PSA level < 1 ng/ml to 82.9% and 100% at PSA levels > 4 ng/ml and > 10 ng/ml, respectively. In the subgroup of high-risk patients referred for primary staging, 42% demonstrated metastatic disease. Restaging of advanced recurrent PCa revealed detectability of PSMA positive tumor lesions in 85% of the scans.

CONCLUSIONS

[99mTc]Tc-PSMA-I&S-SPECT/CT was useful in PSMA-targeted imaging of PCa at various clinical stages. At low PSA levels (< 4 ng/ml), detection rates of [99mTc]Tc-PSMA-I&S-SPECT/CT in BCR are clearly inferior to data reported for PET-imaging and should thus only be considered for lesion detection if imaging with PET is unavailable. However, at higher PSA levels (> 4 ng/ml) [99mTc]Tc-PSMA-I&S-SPECT/CT provides high detection rates in BCR. [99mTc]Tc-PSMA-I&S-SPECT/CT can also be used for primary staging and for restaging of advanced recurrent PCa. However, further studies are needed to assess the clinical value in these indications.

Design of defect-chemical properties and device performance in memristive systems

Future development of the modern nanoelectronics and its flagships internet of things, artificial intelligence, and neuromorphic computing is largely associated with memristive elements, offering a spectrum of inevitable functionalities, atomic level scalability, and low-power operation. However, their development is limited by significant variability and still phenomenologically orientated materials' design strategy. Here, we highlight the vital importance of materials' purity, demonstrating that even parts-per-million foreign elements substantially change performance. Appropriate choice of chemistry and amount of doping element selectively enhances the desired functionality. Dopant/impurity-dependent structure and charge/potential distribution in the space-charge layers and cell capacitance determine the device kinetics and functions. The relation between chemical composition/purity and switching/neuromorphic performance is experimentally evidenced, providing directions for a rational design of future memristive devices.

Hospital Regimens Including Probiotics Guide the Individual Development of the Gut Microbiome of Very Low Birth Weight Infants in the First Two Weeks of Life

BACKGROUND

It is unknown to what extent the microbiome of preterm infants is influenced by hospital regimens including the use of different probiotics when it comes to the prevention of necrotizing enterocolitis (NEC).

METHODS

Prospective controlled multicenter cohort study including very low birth weight infants from three neonatal intensive care units (NICUs) between October 2015 and March 2017. During this time span, stool was sampled every other day during the first two weeks and samples were subjected to amplicon-based microbiome analyses. Out of these, seventeen negative controls were processed (German Registry of Clinical Trials (No.: DRKS00009290)).

RESULTS

The groups (3 × 18 infants) showed no statistically significant difference regarding gestational age, birth weight, APGAR scores and oxygen demand. 2029 different taxa were detected, including Enterococcus and Staphylococcus, as well as the probiotic genera Lactobacillus and Bifidobacterium predominating. The bacterial load was found to increase earlier on when probiotics were used. Without probiotics administration, Lactobacillus and Bifidobacterium contributed only marginally to the fecal microbiome. Some infants did not respond to probiotic administration. The samples from all centers participating reached a very similar diversity after two weeks while the microbiome samples from all three centers clustered significantly yet varied from each other.

CONCLUSION

Probiotics proved to be safe and initiated an earlier increase of bacterial load (with marked individual divergences), which might play a crucial role in the prevention of neonatal morbidities. Meconium was found not to be free of bacterial DNA, and oral antibiotics did not influence the fecal microbiome development negatively, and hospital regimes led to a center-specific, distinct cluster formation.

Camera-based sample-position detection and control for microgravity electrostatic levitation

This paper presents a method for high-speed sample detection and position control in an electrostatic levitator. The algorithm uses images acquired from two charge coupled device cameras and allows for robust and reliable detection of the sample position under various process conditions. The results show improvements over position sensitive detector systems especially under harsh environments and during autonomous operation under microgravity conditions. The position of samples with a radius from 0.6 mm to 1.1 mm is detected in three dimensions with an accuracy of ±40 μm inside a 7 mm × 7 mm × 7 mm levitation area. The two orthogonally arranged cameras, recording images at a resolution of 260 px × 260 px, are used to calculate the position every 5 ms. The control model and the corresponding position controller for the three axes are presented as well. The system was successfully tested in the laboratory and under microgravity conditions at the drop tower, during parabolic flights, and on the MAPHEUS sounding rocket.

Gentoo penguins (Pygoscelis papua) react to underwater sounds

Marine mammals and diving birds face several physiological challenges under water, affecting their thermoregulation and locomotion as well as their sensory systems. Therefore, marine mammals have modified ears for improved underwater hearing. Underwater hearing in birds has been studied in a few species, but for the record-holding divers, such as penguins, there are no detailed data. We played underwater noise bursts to gentoo penguins (Pygoscelis papua) in a large tank at received sound pressure levels between 100 and 120 dB re 1 µPa RMS. The penguins showed a graded reaction to the noise bursts, ranging from no reactions at 100 dB to strong reactions in more than 60% of the playbacks at 120 dB re 1 µPa. The responses were always directed away from the sound source. The fact that penguins can detect and react to underwater stimuli may indicate that they make use of sound stimuli for orientation and prey detection during dives. Further, it suggests that penguins may be sensitive to anthropogenic noise, like many species of marine mammals.

Photochemical mechanism of DEACM uncaging: a combined time-resolved spectroscopic and computational study

Combined spectroscopic and computational studies elucidate excited-state photocleavage in DEACM cages, explaining vastly different time scales for different leaving groups.

A Bayesian approach for the analysis of error rate studies in forensic science

Over the past decade, the field of forensic science has received recommendations from the National Research Council of the U.S. National Academy of Sciences, the U.S. National Institute of Standards and Technology, and the U.S. President's Council of Advisors on Science and Technology to study the validity and reliability of forensic analyses. More specifically, these committees recommend estimation of the rates of occurrence of erroneous conclusions drawn from forensic analyses. "Black box" studies for the various subjective feature-based comparison methods are intended for this purpose. In general, "black box" studies often have unbalanced designs, comparisons that are not independent, and missing data. These aspects pose difficulty in the analysis of the results and are often ignored. Instead, interpretation of the data relies on methods that assume independence between observations and a balanced experiment. Furthermore, all of these projects are interpreted within the frequentist framework and result in point estimates associated with confidence intervals that are confusing to communicate and understand. We propose to use an existing likelihood-free Bayesian inference method, called Approximate Bayesian Computation (ABC), that is capable of handling unbalanced designs, dependencies among the observations, and missing data. ABC allows for studying the parameters of interest without recourse to incoherent and misleading measures of uncertainty such as confidence intervals. By taking into account information from all decision categories for a given examiner and information from the population of examiners, our method also allows for quantifying the risk of error for the given examiner, even when no error has been recorded for that examiner. This opens the door to the detection of behavioural patterns in the decision-making of examiners through their ABC rate estimates. These patterns could be used to detect error prone examiners, enabling additional training efforts to be more tailored to each examiner, limiting the risk of errors before they occur. We illustrate our proposed method by reanalysing the results of the "Noblis Black Box" study by Ulery et al. [18]. We did not choose this study because we disagree with their results, but because it is a good example of a study with dependent observations and missing data, and the data is publicly available. The ABC estimates for the population generally agreed with Ulery et al.'s plug-in estimates. However, credible intervals obtained from ABC are much wider than the confidence intervals for the corresponding parameter estimates that did not account for the dependencies among observations.

ARTEC-A furnace module for directional solidification and quenching experiments in microgravity

A new experimental design for directional solidification experiments with high cooling rates under microgravity conditions is presented. The aerogel-based furnace module ARTEC (AeRogel TEchnology for Cast alloys) developed at DLR extends the earlier presented sounding rocket facility ARTEX by enabling a transition from low to high solidification velocities and a simultaneous operation of five independent furnaces in the same sounding rocket module. The furnaces for directional solidification are equipped with thermally insulating aerogels as a crucible material. Their optical transparency allows the control of the solidification parameters (velocity and temperature gradient) with optical methods in the lab. In ARTEC, a drastically increased solidification velocity is achieved by contacting the sample with a movable cooling-rod during processing. Therefore, a better theoretical understanding of the influence of a sudden change in solidification velocity on microstructure formation is obtained. Carrying out experiments in microgravity gives access to purely diffusive solidification conditions. Hence, convection free-growth can be compared with growth subject to natural (earth) and/or forced-convection (earth and space). Furthermore, alloys with high density differences in their alloy components and, hence, also between the primary solidifying phase and the surrounding liquid can be studied without the negative influence of fluid-flow or macrosegregation being present.

Familial Variant of Antithrombin III (AT III Bligny, 47Arg to His) Associated with Protein C Deficiency

The association of a variant of antithrombin III (AT III Bligny) and protein C deficiency is described in a 36-year-old patient having suffered from severe thrombotic episodes. His mother has protein C deficiency and showed a single episode of thrombophlebitis following surgery. His father, sister and daughter have the variant AT III and are asymptomatic. The abnormal AT III was characterized in plasma by the discrepancy between a normal progressive activity and a reduced heparin cofactor activity. This variant AT III was purified, separated from the normal protein by heparin-Sepharose chromatography and was eluted with increased NaCI concentrations. At pH 7.4, the variant AT III eluted at lower (0.3 to 0.5 M) NaCI concentrations than normal (1 to 1.5 M) AT III, thus demonstrating a decreased affinity for heparin. At pH 6.0, however, the abnormal molecule bound more avidly to heparin-Sepharose and was eluted like normal AT III at pH 7.4. Similarly, the heparin enhancement of intrinsic fluorescence of the variant AT III, markedly reduced at pH 7.4, was normalized at pH 6.0. The abnormal AT III showed a normal antiprotease activity, a normal molecular weight by SDS-PAGE, but displayed only a partial immunological identity with the normal protein. Analysis of amplified genomic DNA from this patient by dot-blot demonstrates a heterozygous substitution of arginine by histidine at position 47.

SPECT-Befunde bei Hemiparkinson-Syndrom mit 99mTc-HMPAO

The symptoms of Parkinson’s disease often begin on one side of the body and continue to do so as the disease progresses. First SPECT results in 4 patients with hemiparkinsonism using 99mTc-HMPAO as perfusion marker are reported. Three patients exhibited reduced tracer uptake in the contralateral basal ganglia One patient who was under therapy for 1 year, showed a different perfusion pattern with reduced uptake in both basal ganglia. These results might indicate reduced perfusion secondary to reduced striatal neuronal activity.

Picosecond activation of the DEACM photocage unravelled by VIS-pump-IR-probe spectroscopy

The light-induced ultrafast uncaging process of the [7-(diethylamino)coumarin-4-yl]methyl (DEACM) cage is measured by time-resolved visible-pump-infrared-probe spectroscopy, and supported by steady-state absorption spectroscopy in the visible and infrared spectral regions. Understanding the uncaging process is important because its favorable properties make DEACM an interesting case for chemical and biological applications. It has a convenient absorption in the visible spectral range, and is relatively easily modified to carry leaving groups (LGs) such as nucleotides, substrates or inhibitors, which are inactive when bound and active when released. Previous work suggested a lower limit for the uncaging rate, which places it among the fastest available cages. Here, we determine the photodissociation directly to occur on the picosecond time scale by monitoring the appearance of the released LG in the infrared spectral region. In the present study, azide (N₃) is chosen as an LG to monitor photodissociation because its vibrational mode is spectrally isolated (hence easy to follow) and its absorption wavenumber is sensitive to local structural rearrangements. The uncaging process is recorded up to 3 nanoseconds and compared to the collected steady-state spectra. The free LG appears on a picosecond time scale, rendering this one of the fastest known cages. No evidence is found for a tight-ion pair (TIP) preceding the free LG. The uncaging mechanism is found to be slowed down upon the addition of water to acetonitrile.

Effects of ketamine on brain function during smooth pursuit eye movements

The uncompetitive NMDA receptor antagonist ketamine has been proposed to model symptoms of psychosis. Smooth pursuit eye movements (SPEM) are an established biomarker of schizophrenia. SPEM performance has been shown to be impaired in the schizophrenia spectrum and during ketamine administration in healthy volunteers. However, the neural mechanisms mediating SPEM impairments during ketamine administration are unknown. In a counter-balanced, placebo-controlled, double-blind, within-subjects design, 27 healthy participants received intravenous racemic ketamine (100 ng/mL target plasma concentration) on one of two assessment days and placebo (intravenous saline) on the other. Participants performed a block-design SPEM task during functional magnetic resonance imaging (fMRI) at 3 Tesla field strength. Self-ratings of psychosis-like experiences were obtained using the Psychotomimetic States Inventory (PSI). Ketamine administration induced psychosis-like symptoms, during ketamine infusion, participants showed increased ratings on the PSI dimensions cognitive disorganization, delusional thinking, perceptual distortion and mania. Ketamine led to robust deficits in SPEM performance, which were accompanied by reduced blood oxygen level dependent (BOLD) signal in the SPEM network including primary visual cortex, area V5 and the right frontal eye field (FEF), compared to placebo. A measure of connectivity with V5 and FEF as seed regions, however, was not significantly affected by ketamine. These results are similar to the deviations found in schizophrenia patients. Our findings support the role of glutamate dysfunction in impaired smooth pursuit performance and the use of ketamine as a pharmacological model of psychosis, especially when combined with oculomotor biomarkers. Hum Brain Mapp 37:4047-4060, 2016. © 2016 Wiley Periodicals, Inc.

Structural differences between glycosylated, disulfide-linked heterodimeric Knob-into-Hole Fc fragment and its homodimeric Knob-Knob and Hole-Hole side products

An increasing number of bispecific therapeutic antibodies are progressing through clinical development. The Knob-into-Hole (KiH) technology uses complementary mutations in the CH3 region of the antibody Fc fragment to achieve heavy chain heterodimerization. Here we describe the X-ray crystal structures of glycosylated and disulfide-engineered heterodimeric KiH Fc fragment and its homodimeric Knob-Knob and Hole-Hole side products. The heterodimer structure confirms the KiH design principle and supports the hypothesis that glycosylation stabilizes a closed Fc conformation. Both homodimer structures show parallel Fc fragment architectures, in contrast to recently reported crystal structures of the corresponding aglycosylated Fc fragments which in the absence of disulfide mutations show an unexpected antiparallel arrangement. The glycosylated Knob-Knob Fc fragment is destabilized as indicated by variability in the relative orientation of its CH3 domains. The glycosylated Hole-Hole Fc fragment shows an unexpected intermolecular disulfide bond via the introduced Y349C Hole mutation which results in a large CH3 domain shift and a new CH3-CH3 interface. The crystal structures of glycosylated, disulfide-linked KiH Fc fragment and its Knob-Knob and Hole-Hole side products reported here will facilitate further design of highly efficient antibody heterodimerization strategies.

[Dacryoliths and Iatrogenic Foreign Bodies as Classical Triggers for Inflammatory Pseudotumors of the Lacrimal Drainage System]

BACKGROUND

Tumors of the lacrimal duct are rare. Inflammatory pseudotumors do not represent neoplasias as such. Chronic inflammation may lead to an angiomatous granulation tissue.

PATIENTS

The first case presents a 53-year-old male patient suffering a mass of the mediocaudal orbit after an acute dacryocystitis has been cured. Using diagnostic dacryoendoscopy, a large dacryolith was detected. Removing the concrement, via external dacryocystorhinostomy, a polypous tissue appeared which was resected as well. The second case concerns a 29-year-old female patient. She had a lacrimal surgery with stenting seven years prior to surgery. The patient's history revealed recurrent mucous secretion of the tear duct and tenderness of the lacrimal sac. An intrasaccal silicon foreign body could be confirmed by dacryoendoscopy. An external dacryocystorhinostomy was performed and the material was extracted. Hereby, an inflammatory tissue mass filling the whole efferent tear duct was removed.

RESULTS

In both patients, external dacryocystorhinostomy was performed complication-free. Surgery enabled the reconstruction of the nasolacrimal duct. Temporary autostable silicon intubation was inserted into the nasolacrimal duct (case 1 and 2), as well into osteotomy (case 2). Histologically, reactive granulation tissue was confirmed. During the follow-up of 9 months (patient 1) and 12 months (patient 2), patients were free of complaints. Lacrimal stentings were removed uneventfully and completely.

CONCLUSIONS

Dacryoliths and intrasaccal foreign bodies may cause a chronic dacryocystitis. Due to inflammation, reactive tissue proliferation can be initiated. In these cases, a hypertrophic granulation arose. Endogenous (dacryoliths) and exogenous (iatrogenic foreign bodies) triggers may be underlying reasons. Histological examination is essential for differentiating other inflammatory pathologies or tumors.

Caregiver Child Interaction Patterns in Two Cultures in Relation to Nutritional Intake

The major focus of the present project was the relation between caregiver behaviour towards toddlers, and caregiver and toddler nutritional intake across two cultures. Kenyan subjects were 110 toddlers, 18-30 months of age and their caregivers; Egyptian subjects were 153 toddlers, 18-30 months of age and their caregivers. Based on monthly observations and maternal report, food intake values were calculated for both mothers and toddlers in both countries. In Kenya, based on bimonthly observations, five measures of caregiver behaviour were collected; based on monthly observations, nine measures of caregiver behaviour were collected in Egypt. Results indicated that in both countries caregiver behaviours toward their toddlers were driven primarily by toddler rather than by maternal intake. However, the specific pattern of relations differed across each culture. Specifically, in Egypt, more adequately nourished toddlers received more appropriate stimulation from caregivers. In Kenya, more adequately nourished toddlers had less physical contact with their caregivers and their caregivers responded verbally to their vocalisations less than they did for poorly nourished toddlers.

Exploring photochemistry of p-bromophenylsulfonyl, p-tolylsulfonyl and methylsulfonyl azides by ultrafast UV-pump–IR-probe spectroscopy and computations

The photochemistry of three sulfonylazides was studied by femtosecond time-resolved infrared (TRIR) spectroscopy and quantum chemical computations.

Raman spectroscopy as probe of nanometre-scale strain variations in graphene

Confocal Raman spectroscopy has emerged as a major, versatile workhorse for the non-invasive characterization of graphene. Although it is successfully used to determine the number of layers, the quality of edges, and the effects of strain, doping and disorder, the nature of the experimentally observed broadening of the most prominent Raman 2D line has remained unclear. Here we show that the observed 2D line width contains valuable information on strain variations in graphene on length scales far below the laser spot size, that is, on the nanometre-scale. This finding is highly relevant as it has been shown recently that such nanometre-scaled strain variations limit the carrier mobility in high-quality graphene devices. Consequently, the 2D line width is a good and easily accessible quantity for classifying the crystalline quality, nanometre-scale flatness as well as local electronic properties of graphene, all important for future scientific and industrial applications.

Raman spectroscopy has become an invaluable tool for graphene characterisation, yet the nature of the broadening of the Raman 2D line remains unclear. Here, Stampfer et al. show that the Raman 2D line width is a measure of nanometre-scale strain variations in graphene on insulating substrates.

[The relevant axial deviation: Diagnostics and therapy for correction osteotomies of the femur]

Intraoperative assessment of the femoral axis, length and torsion can be difficult. A postoperative torsional discrepancy is a common but rarely diagnosed condition. A clinical evaluation of femoral torsion is limited, especially in the early postoperative period. Conventional radiographs are a reliable diagnostic tool for evaluation of discrepancies of leg length and axis. Computed tomography remains the gold standard for assessment of torsional discrepancies. Because of the wide variability of the physiological femoral torsion, the clinical impact of a torsional discrepancy in individual cases remains unclear. There is a general recommendation for revision in cases of intraindividual deviations of more than 15°; however, most patients with deviations even greater than 15° are asymptomatic. Therefore, the indications for correction should be carefully considered in each individual case. The patient level of activity is a crucial point in decision-making for correction osteotomy. Before correction osteotomy, the surgeon has to make a detailed biomechanical analysis of the leg. Early correction is recommended in most cases. Detailed knowledge of the patient medical history is needed for preoperative planning. Prior surgeries can have a significant impact on the choice of the surgical approach and stabilization technique.

Posterolateral fusion in acute traumatic thoracolumbar fractures: a comparison of demineralized bone matrix and autologous bone graft

INTRODUCTION Alternative fusion expanders are in clinical use for instrumented posterolateral fusion (PLF) to avoid donor site morbidity in autologous bone graft (ABG) harvesting. Purpose of this study was to evaluate demineralized bone matrix (DBM) in PLF as alternative to the gold standard of ABG in acute traumatic vertebral body fractures of the thoracolumbar spine. MATERIAL AND METHODS We retrospectively identified 101 patients with acute traumatic vertebral body fractures of the thoracic and lumbar spine who were treated with instrumented PLF in our level one trauma center between 2005 and 2011. Patients with a primary paraplegia, osteodepriving disease or loss to follow-up had been excluded. Until August 2008, autologous bone graft harvested from the posterior iliac crest was used in PLF (control group n = 46). Starting September 2008, DBM was used as fusion expander in PLF (study group n = 16). Clinical and radiological evaluation was performed with a minimum followup of 18 months to assess the clinical and radiological outcome. RESULTS We found a fusion rate of 94% in patients undergoing PLF with the use of DBM and 100% with the use of ABG. There was one major complication of deep infection in the DBM group and two cases of superficial wound infection in the ABG group. We discovered a trend of reduced operating time with the use of DBM. CONCLUSIONS DBM leads to a similar fusion rate as the use of ABG in patients undergoing PLF for acute traumatic vertebral body fractures of the thoracic and lumbar spine. DBM is associated with reduced operating time.

LEVEL OF EVIDENCE III

case-control study Key words: demineralized bone matrix instrumented posterolateral fusion, acute traumatic vertebral body fracture, thoracolumbar spine, autologous bone graft.

Carbapenem-resistant Enterobacteriaceae and the correlation between carbapenem and fluoroquinolone usage and resistance in the US military health system

Whether carbapenem or fluoroquinolone usage is correlated with carbapenem-resistant Enterobacteriaceae (CRE) has not been investigated at the level of an entire US nationwide managed health care system. We analyzed 75 million person-years of surveillance and 1,969,315 cultures from all 266 hospitals in the geographically dispersed US military health system. Incidences of CRE remained under 1 case per 100,000 person-years. Incidences of CRE increased relative to 2005 baseline levels in 3 of 7 subsequent years, then decreased in 2012 (P<0.05). Incident proportions of carbapenem resistance (CR) differed significantly among years, geographical regions, and bacterial species. Although use and resistance strongly correlated (R>0.80) for several "drug-bug" combinations, none were significant at the national or facility level. One exception was that inpatient consumption of fluoroquinolones was significantly correlated (P=0.0007) with CR in Escherichia coli when data from the major referral centers of the Southern and Northern regions were combined.

Activation of the δ-opioid receptor promotes cutaneous wound healing by affecting keratinocyte intercellular adhesion and migration

BACKGROUND AND PURPOSE

In addition to its analgesic functions, the peripheral opioid receptor system affects skin homeostasis by influencing cell differentiation, migration and adhesion; also, wound healing is altered in δ-opioid receptor knockout mice (DOPr^–/–). Hence, we investigated δ-opioid receptor effects on the expression of several proteins of the desmosomal junction complex and on the migratory behaviour of keratinocytes.

EXPERIMENTAL APPROACH

Expression levels of desmosomal cadherins in wild-type and DOPr^–/– mice, and the morphology of intercellular adhesion in human keratinocytes were analysed by immunofluorescence. To investigate the δ-opioid receptor activation pathway, protein expression was studied using Western blot and its effect on cellular migration determined by in vitro live cell migration recordings from human keratinocytes.

KEY RESULTS

Expression of the desmosomal cadherins, desmogleins 1 and 4, was up-regulated in skin from DOPr^–/– mice, and down-regulated in δ-opioid receptor-overexpressing human keratinocytes. The localization of desmoplakin expression was rearranged from linear arrays emanating from cell borders to puncta in cell periphery, resulting in less stable intercellular adhesion. Migration and wound recovery were enhanced in human keratinocyte monolayers overexpressing δ-opioid receptors in vitro. These δ-opioid receptor effects were antagonized by specific PKCα/β inhibition indicating they were mediated through the PKC signalling pathway. Finally, cells overexpressing δ-opioid receptors developed characteristically long but undirected protrusions containing filamentous actin and δ-opioid receptors, indicating an enhanced migratory phenotype.

CONCLUSION AND IMPLICATIONS

Opioid receptors affect intercellular adhesion and wound healing mechanisms, underlining the importance of a cutaneous neuroendocrine system in wound healing and skin homeostasis.

LINKED ARTICLES

This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2