Synthesis and Raman Detection of 5-Amino-2-mercaptobenzimidazole Self-Assembled Monolayers in Nanoparticle-on-a-Mirror Plasmonic Cavity Driven by Dielectric Waveguides

Functionalization of metallic surfaces by molecular monolayers is a key process in fields such as nanophotonics or biotechnology. To strongly enhance light-matter interaction in such monolayers, nanoparticle-on-a-mirror (NPoM) cavities can be formed by placing metal nanoparticles on such chemically functionalized metallic monolayers. In this work, we present a novel functionalization process of gold surfaces using 5-amino-2-mercaptobenzimidazole (5-A-2MBI) molecules, which can be used for upconversion from THz to visible frequencies. The synthesized surfaces and NPoM cavities are characterized by Raman spectroscopy, atomic force microscopy (AFM), and advancing-receding contact angle measurements. Moreover, we show that NPoM cavities can be efficiently integrated on a silicon-based photonic chip performing pump injection and Raman-signal extraction via silicon nitride waveguides. Our results open the way for the use of 5-A-2MBI monolayers in different applications, showing that NPoM cavities can be effectively integrated with photonic waveguides, enabling on-chip enhanced Raman spectroscopy or detection of infrared and THz radiation.

Extensive photochemical restructuring of molecule-metal surfaces under room light

The molecule-metal interface is of paramount importance for many devices and processes, and directly involved in photocatalysis, molecular electronics, nanophotonics, and molecular (bio-)sensing. Here the photostability of this interface is shown to be sensitive even to room light levels for specific molecules and metals. Optical spectroscopy is used to track photoinduced migration of gold atoms when functionalised with different thiolated molecules that form uniform monolayers on Au. Nucleation and growth of characteristic surface metal nanostructures is observed from the light-driven adatoms. By watching the spectral shifts of optical modes from nanoparticles used to precoat these surfaces, we identify processes involved in the photo-migration mechanism and the chemical groups that facilitate it. This photosensitivity of the molecule-metal interface highlights the significance of optically induced surface reconstruction. In some catalytic contexts this can enhance activity, especially utilising atomically dispersed gold. Conversely, in electronic device applications such reconstructions introduce problematic aging effects.

Astrocytes actively support long-range molecular clock synchronization of segregated neuronal populations

In mammals, the suprachiasmatic nucleus of the hypothalamus is the master circadian pacemaker that synchronizes the clocks in the central nervous system and periphery, thus orchestrating rhythms throughout the body. However, little is known about how so many cellular clocks within and across brain circuits can be effectively synchronized. In this work, we investigated the implication of two possible pathways: (i) astrocytes-mediated synchronization and (ii) neuronal paracrine factors-mediated synchronization. By taking advantage of a lab-on-a-chip microfluidic device developed in our laboratory, here we report that both pathways are involved. We found the paracrine factors-mediated synchronization of molecular clocks is diffusion-limited and, in our device, effective only in case of a short distance between neuronal populations. Interestingly, interconnecting astrocytes define an active signaling channel that can synchronize molecular clocks of neuronal populations also at longer distances. At mechanism level, we found that astrocytes-mediated synchronization involves both GABA and glutamate, while neuronal paracrine factors-mediated synchronization occurs through GABA signaling. These findings identify a previously unknown role of astrocytes as active cells that might distribute long-range signals to synchronize the brain clocks, thus further strengthening the importance of reciprocal interactions between glial and neuronal cells in the context of circadian circuitry.

Nanoparticles for Drug and Gene Delivery in Pediatric Brain Tumors' Cancer Stem Cells: Current Knowledge and Future Perspectives

Primary malignant brain tumors are the most common solid neoplasm in childhood. Despite recent advances, many children affected by aggressive or metastatic brain tumors still present poor prognosis, therefore the development of more effective therapies is urgent. Cancer stem cells (CSCs) have been discovered and isolated in both pediatric and adult patients with brain tumors (e.g., medulloblastoma, gliomas and ependymoma). CSCs are a small clonal population of cancer cells responsible for brain tumor initiation, maintenance and progression, displaying resistance to conventional anticancer therapies. CSCs are characterized by a specific repertoire of surface markers and intracellular specific pathways. These unique features of CSCs biology offer the opportunity to build therapeutic approaches to specifically target these cells in the complex tumor bulk. Treatment of pediatric brain tumors with classical chemotherapeutic regimen poses challenges both for tumor location and for the presence of the blood-brain barrier (BBB). Lastly, the application of chemotherapy to a developing brain is followed by long-term sequelae, especially on cognitive abilities. Novel avenues are emerging in the therapeutic panorama taking advantage of nanomedicine. In this review we will summarize nanoparticle-based approaches and the efficacy that NPs have intrinsically demonstrated and how they are also decorated by biomolecules. Furthermore, we propose novel cargoes together with recent advances in nanoparticle design/synthesis with the final aim to specifically target the insidious CSCs population in the tumor bulk.

Giant mid-IR resonant coupling to molecular vibrations in sub-nm gaps of plasmonic multilayer metafilms

Nanomaterials capable of confining light are desirable for enhancing spectroscopies such as Raman scattering, infrared absorption, and nonlinear optical processes. Plasmonic superlattices have shown the ability to host collective resonances in the mid-infrared, but require stringent fabrication processes to create well-ordered structures. Here, we demonstrate how short-range-ordered Au nanoparticle multilayers on a mirror, self-assembled by a sub-nm molecular spacer, support collective plasmon-polariton resonances in the visible and infrared, continuously tunable beyond 11 µm by simply varying the nanoparticle size and number of layers. The resulting molecule-plasmon system approaches vibrational strong coupling, and displays giant Fano dip strengths, SEIRA enhancement factors ~ 10⁶, light-matter coupling strengths g ~ 100 cm^-1, Purcell factors ~ 10⁶, and mode volume compression factors ~ 10⁸. The collective plasmon-polariton mode is highly robust to nanoparticle vacancy disorder and is sustained by the consistent gap size defined by the molecular spacer. Structural disorder efficiently couples light into the gaps between the multilayers and mirror, enabling Raman and infrared sensing of sub-picolitre sample volumes.

Label-free monitoring of proteins in optofluidic hollow-core photonic crystal fibres

The fluorescent detection of proteins without labels or stains, which affect their behaviour and require additional genetic or chemical preparation, has broad applications to biological research. However, standard approaches require large sample volumes or analyse only a small fraction of the sample. Here we use optofluidic hollow-core photonic crystal fibres to detect and quantify sub-microlitre volumes of unmodified bovine serum albumin (BSA) protein down to 100 nM concentrations. The optofluidic fibre's waveguiding properties are optimised for guidance at the (auto)fluorescence emission wavelength, enabling fluorescence collection from a 10 cm long excitation region, increasing sensitivity. The observed spectra agree with spectra taken from a conventional cuvette-based fluorimeter, corrected for the guidance properties of the fibre. The BSA fluorescence depended linearly on BSA concentration, while only a small hysteresis effect was observed, suggesting limited biofouling of the fibre sensor. Finally, we briefly discuss how this method could be used to study aggregation kinetics. With small sample volumes, the ability to use unlabelled proteins, and continuous flow, the method will be of interest to a broad range of protein-related research.

An ESPGHAN Position Paper on the Use of Low-FODMAP Diet in Pediatric Gastroenterology

Excluding oligo-, di-, monosaccharides and polyols (FODMAPs) from the diet is increasingly being used to treat children with gastrointestinal complaints. The aim of this position paper is to review the available evidence on the safety and efficacy of its use in children and provide expert guidance regarding practical aspects in case its use is considered . Members of the Gastroenterology Committee, the Nutrition Committee and the Allied Health Professionals Committee of the European Society for Pediatric Gastroenterology Hepatology and Nutrition contributed to this position paper. Clinical questions regarding initiation, introduction, duration, weaning, monitoring, professional guidance, safety and risks of the diet are addressed. A systematic literature search was performed from 2005 to May 2021 using PubMed, MEDLINE and Cochrane Database of Systematic Reviews. In the absence of evidence, recommendations reflect the expert opinion of the authors. The systematic literature search revealed that the low-FODMAP diet has not been comprehensively studied in children. Indications and contraindications of the use of the diet in different pediatric gastroenterological conditions are discussed and practical recommendations are formulated. There is scarce evidence to support the use of a low-FODMAP diet in children with Irritable Bowel Syndrome and no evidence to recommend its use in other gastrointestinal diseases and complaints in children. Awareness of how and when to use the diet is crucial, as a restrictive diet may impact nutritional adequacy and/or promote distorted eating in vulnerable subjects. The present article provides practical safety tips to be applied when the low-FODMAP diet is considered in children.

Hollow-core optical fibre sensors for operando Raman spectroscopy investigation of Li-ion battery liquid electrolytes

Improved analytical tools are urgently required to identify degradation and failure mechanisms in Li-ion batteries. However, understanding and ultimately avoiding these detrimental mechanisms requires continuous tracking of complex electrochemical processes in different battery components. Here, we report an operando spectroscopy method that enables monitoring the chemistry of a carbonate-based liquid electrolyte during electrochemical cycling in Li-ion batteries with a graphite anode and a LiNi_0.8Mn_0.1Co_0.1O₂ cathode. By embedding a hollow-core optical fibre probe inside a lab-scale pouch cell, we demonstrate the effective evolution of the liquid electrolyte species by background-free Raman spectroscopy. The analysis of the spectroscopy measurements reveals changes in the ratio of carbonate solvents and electrolyte additives as a function of the cell voltage and show the potential to track the lithium-ion solvation dynamics. The proposed operando methodology contributes to understanding better the current Li-ion battery limitations and paves the way for studies of the degradation mechanisms in different electrochemical energy storage systems.

Detecting mid-infrared light by molecular frequency upconversion in dual-wavelength nanoantennas

[Figure: see text].

OS13.3.A Establishment of a novel system to specifically trace and ablate quiescent/slow cycling cells in high-grade glioma

BACKGROUND

High-grade gliomas are the most common malignant brain tumors, with poor prognosis due to recurrence and tumor infiltration after surgical removal and chemotherapy. Quiescent/slow cycling stem cells have been proposed to be one of the main players of tumor relapse but their involvement in in the infiltration remain unclear. Despite they have been described in mouse models or after transcriptional profiling of human tumor samples, their direct visualization, targeting and ablation remains a challenge.

MATERIAL AND METHODS

Tumors were induced over-expressing oncogenic forms of MET and p53 in the subventricular zone (SVZ) of P2 mouse brain as well as human forebrain organoids. The co-expression with specific cell cycle sensors as well as lineage specific CreERT2 under control of stem cells promoters allowed to visualize and target glioma stem cells.

RESULTS

Here, we used a fluorescent cell cycle sensor to visualize quiescent tumor cells in mouse brain cancer and human cancer organoids. In particular, we characterized them within the tumor revealing the invasiveness capacity of slow cycling tumor cells. Furthermore, we generated a new system to specifically trace and ablate such cells. Indeed, lineage tracing experiments allowed to trace quiescent Prom1 progeny in the tumors after temozolomide treatment. In addition, the selective ablation of qProm1 in mouse brain cancer reduced tumor infiltration. Finally, time-lapse experiments showed that slow cycling cells are also able to infiltrate co-cultured human brain cancer organoids.

CONCLUSION

Overall, our data show that quiescent/slow cycling cells are key driver of tumor invasiveness, the major malignant feature of high-grade brain cancer.

Disease Activity Patterns in the First 5 Years After Diagnosis in Children With Ulcerative Colitis: A Population-Based Study

BACKGROUND

The aim of this study was to define clusters of activity in a population-based cohort during the first 5 years after diagnosis in children with ulcerative colitis [UC] and to identify early prognostic risk factors.

METHODS

All UC patients from the SIGENP IBD registry with a complete follow-up of at least 5 years were included. Active disease was defined every 6 months in the presence of at least one of the following: clinical activity [Paediatric Ulcerative Colitis Activity Index ≥ 35]; endoscopic activity [Mayo score ≥ 1]; faecal calprotectin > 250 µg/g; hospitalization; surgery; or treatment escalation. Formula-based clusters were generated based on four published questionnaire-based activity patterns in adults, plus one additional cluster.

RESULTS

In total, 226 patients were identified. Forty-two [19%] had moderate-severe chronically active disease, 31 [14%] chronic-intermittent, 75 [33%] quiescent, 54 [24%] active disease in the first 2 years after the diagnosis, then sustained remission, and 24 [11%] a remission in the first 2 years then an active disease. Mild disease onset along with a lower clinical severity not requiring the use of corticosteroids at 6 months were related to a quiescent disease course at the next follow-up (logistic model area under the curve 0.86 [95% confidence interval 0.78-0.94]; positive predictive value 67%; negative predictive value 70%). Eight per cent of patients needed surgery, none in the quiescent group [p = 0.04].

CONCLUSIONS

More than one-third of children with UC present with a chronically active or intermittent course during the first 5 years of follow-up. A significant group of patients has active disease in the first 2 years and then sustained remission. Interestingly, after initial treatment, one-third of patients have well-controlled disease throughout.

A Systematic Review and Meta-analysis of Paediatric Inflammatory Bowel Disease Incidence and Prevalence Across Europe

BACKGROUND AND AIMS

Inflammatory bowel disease [IBD] is often one of the most devastating and debilitating chronic gastrointestinal disorders in children and adolescents. The main objectives here were to systematically review the incidence and prevalence of paediatric IBD across all 51 European states.

METHODS

We undertook a systematic review and meta-analysis based on PubMed, CINAHL, the Cochrane Library, searches of reference lists, grey literature and websites, covering the period from 1970 to 2018.

RESULTS

Incidence rates for both paediatric Crohn's disease [CD] and ulcerative colitis [UC] were higher in northern Europe than in other European regions. There have been large increases in the incidence of both paediatric CD and UC over the last 50 years, which appear widespread across Europe. The largest increases for CD have been reported from Sweden, Wales, England, the Czech Republic, Denmark and Hungary, and for UC from the Czech Republic, Ireland, Sweden and Hungary. Incidence rates for paediatric CD have increased up to 9 or 10 per 100 000 population in parts of Europe, including Scandinavia, while rates for paediatric UC are often slightly lower than for CD. Prevalence reported for CD ranged from 8.2 per 100 000 to approximately 60 and, for UC, from 8.3 to approximately 30.

CONCLUSIONS

The incidence of paediatric IBD continues to increase throughout Europe. There is stronger evidence of a north-south than an east-west gradient in incidence across Europe. Further prospective studies are needed, preferably multinational and based on IBD registries, using standardized definitions, methodology and timescales.

Improvement of body composition and bone mineral density after enteral nutrition in pediatric Crohn disease

BACKGROUND

The relationship between exclusive enteral nutrition (EEN) and bone status is poorly defined in pediatric Crohn disease (CD).

AIMS

The aim of this study was to investigate the impact of EEN on body composition, nutritional status, and bone mineral density (BMD) in an incident CD cohort.

METHODS

18 newly diagnosed CD children starting EEN for 8 weeks were prospectively enrolled and evaluated at baseline and after 8 (T8), 26 (T26) and 52 weeks (T52) from diagnosis. The Fat Free Mass (FFM) and the Resting Energy Expenditure (REE) were measured through Bioelectrical Impedance (BIA) and the BMD was assessed by dual-energy X-ray (DXA). We compared DXA data of IBD patients to the data obtained in 15 healthy controls.

RESULTS

CD children had a significant lower BMD compared to healthy control both at baseline (p<0.0001), and after EEN therapy at T52 (p=0.0004); although at this latest time point CD children had a significant increase of BMD compared to baseline (p=0.0015). The BIA analysis showed a significant increase at T26 and T52 of FFM and REE. T52. FFM measured by BIA and BMD measured by DXA were significantly correlated.

CONCLUSION

EEN improves nutritional status and bone mineral composition.

Cooperative Energy Transfer Controls the Spontaneous Emission Rate Beyond Field Enhancement Limits

Quantum emitters located in proximity to a metal nanostructure individually transfer their energy via near-field excitation of surface plasmons. The energy transfer process increases the spontaneous emission (SE) rate due to plasmon-enhanced local field. Here, we demonstrate a significant acceleration of the quantum emitter SE rate in a plasmonic nanocavity due to cooperative energy transfer (CET) from plasmon-correlated emitters. Using an integrated plasmonic nanocavity, we realize up to sixfold enhancement in the emission rate of emitters coupled to the same nanocavity on top of the plasmonic enhancement of the local density of states. The radiated power spectrum retains the plasmon resonance central frequency and line shape, with the peak amplitude proportional to the number of excited emitters indicating that the observed cooperative SE is distinct from superradiance. Plasmon-assisted CET offers unprecedented control over the SE rate and allows us to dynamically control the spontaneous emission rate at room temperature which can enable SE rate based optical modulators.

SiNAPS: An implantable active pixel sensor CMOS-probe for simultaneous large-scale neural recordings

Large-scale neural recordings with high spatial and temporal accuracy are instrumental to understand how the brain works. To this end, it is of key importance to develop probes that can be conveniently scaled up to a high number of recording channels. Despite recent achievements in complementary metal-oxide semiconductor (CMOS) multi-electrode arrays probes, in current circuit architectures an increase in the number of simultaneously recording channels would significantly increase the total chip area. A promising approach for overcoming this scaling issue consists in the use of the modular Active Pixel Sensor (APS) concept, in which a small front-end circuit is located beneath each electrode. However, this approach imposes challenging constraints on the area of the in-pixel circuit, power consumption and noise. Here, we present an APS CMOS-probe technology for Simultaneous Neural recording that successfully addresses all these issues for whole-array read-outs at 25 kHz/channel from up to 1024 electrode-pixels. To assess the circuit performances, we realized in a 0.18 μm CMOS technology an implantable single-shaft probe with a regular array of 512 electrode-pixels with a pitch of 28 μm. Extensive bench tests showed an in-pixel gain of 45.4 ± 0.4 dB (low pass, F_-3 dB = 4 kHz), an input referred noise of 7.5 ± 0.67 μV_RMS (300 Hz to 7.5 kHz) and a power consumption <6 μW/pixel. In vivo acute recordings demonstrate that our SiNAPS CMOS-probe can sample full-band bioelectrical signals from each electrode, with the ability to resolve and discriminate activity from several packed neurons both at the spatial and temporal scale. These results pave the way to new generations of compact and scalable active single/multi-shaft brain recording systems.

Hybrid plasmonic nanostructures based on controlled integration of MoS2 flakes on metallic nanoholes

Here, we propose an easy and robust strategy for the versatile preparation of hybrid plasmonic nanopores by means of controlled deposition of single flakes of MoS2 directly on top of metallic holes. The device is realized on silicon nitride membranes and can be further refined by TEM or FIB milling to achieve the passing of molecules or nanometric particles through a pore. Importantly, we show that the plasmonic enhancement provided by the nanohole is strongly accumulated in the 2D nanopore, thus representing an ideal system for single-molecule sensing and sequencing in a flow-through configuration. Here, we also demonstrate that the prepared 2D material can be decorated with metallic nanoparticles that can couple their resonance with the nanopore resonance to further enhance the electromagnetic field confinement at the nanoscale level. This method can be applied to any gold nanopore with a high level of reproducibility and parallelization; hence, it can pave the way to the next generation of solid-state nanopores with plasmonic functionalities. Moreover, the controlled/ordered integration of 2D materials on plasmonic nanostructures opens a pathway towards new investigation of the following: enhanced light emission; strong coupling from plasmonic hybrid structures; hot electron generation; and sensors in general based on 2D materials.

A Synchronous Neural Recording Platform for Multiple High-Resolution CMOS Probes and Passive Electrode Arrays

Electrophysiological signals in the brain are distributed over broad spatial and temporal scales. Monitoring these signals at multiple scales is fundamental in order to decipher how brain circuits operate and might dysfunction in disease. A possible strategy to enlarge the experimentally accessible spatial and temporal scales consists in combining the use of multiple probes with different resolutions and sensing areas. Here, we propose a neural recording system capable of simultaneous and synchronous acquisitions from a new generation of high-resolution CMOS probes (512 microelectrodes, 25 kHz/electrode whole-array sampling frequency) as well as from a custom-designed CMOS-based headstage. While CMOS probes can provide recordings from a large number of closely spaced electrodes on single-shaft devices, the CMOS-based headstage can be used to interface the wide range of available intra- or epi-cortical passive electrode array devices. The current platform was designed to simultaneously manage high-resolution recordings from up to four differently located CMOS probes and from a single 36-channels low-resolution passive electrode array device. The design, implementation, and performances for both ICs and for the FPGA-based interface are presented. Experiments on retina and neuronal culture preparations demonstrate the recording of neural spiking activity for both CMOS devices and the functionality of the system.

Delivery of Brain-Derived Neurotrophic Factor by 3D Biocompatible Polymeric Scaffolds for Neural Tissue Engineering and Neuronal Regeneration

Biopolymers are increasingly employed for neuroscience applications as scaffolds to drive and promote neural regrowth, thanks to their ability to mediate the upload and subsequent release of active molecules and drugs. Synthetic degradable polymers are characterized by different responses ranging from tunable distension or shrinkage to total dissolution, depending on the function they are designed for. In this paper we present a biocompatible microfabricated poly-ε-caprolactone (PCL) scaffold for primary neuron growth and maturation that has been optimized for the in vitro controlled release of brain-derived neurotrophic factor (BDNF). We demonstrate that the designed morphology confers to these devices an enhanced drug delivery capability with respect to monolithic unstructured supports. After incubation with BDNF, micropillared PCL devices progressively release the neurotrophin over 21 days in vitro. Moreover, the bioactivity of released BDNF is confirmed using primary neuronal cultures, where it mediates a consistent activation of BDNF signaling cascades, increased synaptic density, and neuronal survival. These results provide the proof-of-principle on the fabrication process of micropatterned PCL devices, which represent a promising therapeutic option to enhance neuronal regeneration after lesion and for neural tissue engineering and prosthetics.

The miR-139-5p regulates proliferation of supratentorial paediatric low-grade gliomas by targeting the PI3K/AKT/mTORC1 signalling

AIMS

Paediatric low-grade gliomas (pLGGs) are a heterogeneous group of brain tumours associated with a high overall survival: however, they are prone to recur and supratentorial lesions are difficult to resect, being associated with high percentage of disease recurrence. Our aim was to shed light on the biology of pLGGs.

METHODS

We performed microRNA profiling on 45 fresh-frozen grade I tumour samples of various histological classes, resected from patients aged ≤16 years. We identified 93 microRNAs specifically dysregulated in tumours as compared to non-neoplastic brain tissue. Pathway analysis of the microRNAs signature revealed PI3K/AKT signalling as one of the centrally enriched oncogenic signalling. To date, activation of the PI3K/AKT pathway in pLGGs has been reported, although activation mechanisms have not been fully investigated yet.

RESULTS

One of the most markedly down-regulated microRNAs in our supratentorial pLGGs cohort was miR-139-5p, whose targets include the gene encoding the PI3K's (phosphatidylinositol 3-kinase) catalytic unit, PIK3CA. We investigated the role of miR-139-5p in regulating PI3K/AKT signalling by the use of human cell cultures derived from supratentorial pLGGs. MiR-139-5p overexpression inhibited pLGG cell proliferation and decreased the phosphorylation of PI3K target AKT and phosphorylated-p70 S6 kinase (p-p70 S6K), a hallmark of PI3K/AKT/mTORC1 signalling activation. The effect of miR-139-5p was mediated by PI3K inhibition, as suggested by the decrease in proliferation and phosphorylation of AKT and p70 S6K after treatment with the direct PI3K inhibitor LY294002.

CONCLUSIONS

These findings provide the first evidence that down-regulation of miR-139-5p in supratentorial pLGG drives cell proliferation by derepressing PI3K/AKT signalling.

Efficacy of a standardized extract of Matricariae chamomilla L., Melissa officinalis L. and tyndallized Lactobacillus acidophilus (HA122) in infantile colic: An open randomized controlled trial

BACKGROUND

Infant colic (IC) is a prevalent physiological event of infants, which can disrupt the child's home environment. We aimed to investigate the effectiveness of a mixture of Matricariae chamomilla L., Melissa officinalis L. and tyndallized Lactobacillus acidophilus (HA122) compared with Lactobacillus reuteri DSM 17938 and with simethicone for the treatment of IC.

METHODS

A multicenter randomized comparative study was conducted in infants with colic, according to Rome III criteria, who were randomly assigned to receive M. chamomilla L., M. officinalis L. and tyndallized L. acidophilus (HA122) (Colimil^® Plus^® ; Milte Italia Spa, Milan, Italy) (Group A), L. reuteri DSM 17938 (Group B) and simethicone (Group C). Treatment was given to subjects for 28 days.

KEY RESULTS

One-hundred and seventy-six patients completed the study. Mean daily crying time at day 28 was significantly lower in group A (-44, 95% CI: -58 to -30, P<.001) and group B (-35, 95% CI: -49 to -20, P<.001) when compared to group C. No significant difference was observed between Group A and Group B (mean difference: -9 minutes, 95% CI -23 to +5, P=.205). At day 28, 39 of 57 (68.4%) of infants in Group C responded to the treatment compared with 57 out of 60 patients (95%) of Group A and 51 out of 59 (86.4%) of Group B (P<.001).

CONCLUSIONS

This study suggests that administration of M. chamomilla L., M. officinalis L. and tyndallized L. acidophilus (HA122) and L. reuteri DSM 17938 are significantly more effective than simethicone in IC.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT02708238.

Dynamics of Templated Assembly of Nanoparticle Filaments within Nanochannels

Nanoparticles (NPs) can self-assemble into complex, organized superstructures on patterned surfaces through fluid-mediated interactions. However, the detailed mechanisms for such NP assemblies are largely unknown. Here, using in situ transmission electron microscopy, the stepwise self-assembly dynamics of hydrophobic gold NPs into long filaments formed on the surfaces of water-filled patterned nanochannel templates is observed. First, the formation of a meniscus between the nanochannel walls, during the slow drying of water, causes accumulation of the NPs in the middle of the nanochannels. Second, owing to the strong van der Waals attraction between the NP ligands, the NPs condense into filaments along the centers of the nanochannels. Filaments with highly fluctuating longitudinal NP densities are also observed to fragment into separated structures. Understanding the intermediate stages of fluid-mediated NP self-assembly on patterned surfaces will have important implications for the controlled formation of templated NP assemblies with numerous applications.

The role of Rabi splitting tuning in the dynamics of strongly coupled J-aggregates and surface plasmon polaritons in nanohole arrays

We have investigated the influence of Rabi splitting tuning on the dynamics of strongly coupled J-aggregate/surface plasmon polariton systems. In particular, the Rabi splitting was tuned by modifying the J-aggregate molecule concentration while a polaritonic system was provided by a nanostructure formed by holes array in a golden layer. From the periodic and concentration changes we have identified, through numerical and experimental steady-state analyses, the best geometrical configuration for maximizing Rabi splitting, which was then used for transient absorption measurements. It was found that in transient absorption spectra, under upper band excitation, two bleaching peaks appear when a nanostructured polaritonic pattern is used. Importantly, their reciprocal distance increases upon increase of J-aggregate concentration, a result confirmed by steady-state analysis. In a similar manner it was also found that the lifetime of the upper band is intimately related to the coupling strength. In particular, we argue that with strong coupling strength, i.e. high J-aggregate concentration, a short lifetime of the upper band has to be expected due to the suppression of the bottleneck effect. This result supports the idea that the dynamics of hybrid systems is profoundly dependent on Rabi splitting.

Broadband absorption enhancement in plasmonic nanoshells-based ultrathin microcrystalline-Si solar cells

With the objective to conceive a plasmonic solar cell with enhanced photocurrent, we investigate the role of plasmonic nanoshells, embedded within a ultrathin microcrystalline silicon solar cell, in enhancing broadband light trapping capability of the cell and, at the same time, to reduce the parasitic loss. The thickness of the considered microcrystalline silicon (μc-Si) layer is only ~1/6 of conventional μc-Si based solar cells while the plasmonic nanoshells are formed by a combination of silica and gold, respectively core and shell. We analyze the cell optical response by varying both the geometrical and optical parameters of the overall device. In particular, the nanoshells core radius and metal thickness, the periodicity, the incident angle of the solar radiation and its wavelength are varied in the widest meaningful ranges. We further explain the reason for the absorption enhancement by calculating the electric field distribution associated to resonances of the device. We argue that both Fabry-Pérot-like and localized plasmon modes play an important role in this regard.

Direct Synthesis of Carbon-Doped TiO2-Bronze Nanowires as Anode Materials for High Performance Lithium-Ion Batteries

Carbon-doped TiO2-bronze nanowires were synthesized via a facile doping mechanism and were exploited as active material for Li-ion batteries. We demonstrate that both the wire geometry and the presence of carbon doping contribute to the high electrochemical performance of these materials. Direct carbon doping for example reduces the Li-ion diffusion length and improves the electrical conductivity of the wires, as demonstrated by cycling experiments, which evidenced remarkably higher capacities and superior rate capability over the undoped nanowires. The as-prepared carbon-doped nanowires, evaluated in lithium half-cells, exhibited lithium storage capacity of ∼306 mA h g(-1) (91% of the theoretical capacity) at the current rate of 0.1C as well as excellent discharge capacity of ∼160 mAh g(-1) even at the current rate of 10 C after 1000 charge/discharge cycles.

3D vertical nanostructures for enhanced infrared plasmonics

The exploitation of surface plasmon polaritons has been mostly limited to the visible and near infrared range, due to the low frequency limit for coherent plasmon excitation and the reduction of confinement on the metal surface for lower energies. In this work we show that 3D--out of plane--nanostructures can considerably increase the intrinsic quality of the optical output, light confinement and electric field enhancement factors, also in the near and mid-infrared. We suggest that the physical principle relies on the combination of far field and near field interactions between neighboring antennas, promoted by the 3D out-of-plane geometry. We first analyze the changes in the optical behavior, which occur when passing from a single on-plane nanostructure to a 3D out-of-plane configuration. Then we show that by arranging the nanostructures in periodic arrays, 3D architectures can provide, in the mid-IR, a much stronger plasmonic response, compared to that achievable with the use of 2D configurations, leading to higher energy harvesting properties and improved Q-factors, with bright perspective up to the terahertz range.

Liposome-Templated Hydrogel Nanoparticles as Vehicles for Enzyme-Based Therapies

Several diseases are related to the lack or to the defective activity of a particular enzyme; therefore, these proteins potentially represent a very interesting class of therapeutics. However, their application is hampered by their rapid degradation and immunogenic side effects. Most attempts to increase the bioavailability of therapeutic enzymes are based on formulations in which the protein is entrapped within a scaffold structure but needs to be released to exert its activity. In this work, an alternative method will be described, designed to keep the enzyme in its active form inside a nanoparticle (NP) without the need to release it, thus maintaining the protective action of the nanoscaffold during the entire period of administration. In this approach, liposomes were used as nanotemplates for the synthesis of polyacrylamide hydrogel NPs under nondenaturing conditions, optimizing the polymer properties to obtain a mesh size small enough to limit the enzyme release while allowing the free diffusion of its substrates and products. The enzyme Cu, Zn-superoxide dismutase was chosen as a test case for this study, but our results indicate that the approach is generalizable to other enzymes. Biocompatible, size-tunable nanoparticles have been obtained, with a good encapsulation efficiency (37%), in which the enzyme maintains its activity. This system represents a promising tool for enzyme-based therapy, which would protect the protein from antibodies and degradation while allowing it to exert its catalytic activity.

Paediatric ulcerative colitis surgery: Italian survey

BACKGROUND AND AIMS

Recent epidemiological studies showed an increase in ulcerative colitis among children, especially in its aggressive form, requiring surgical treatment. Although medical therapeutic strategies are standardized, there is still no consensus regarding indications, timing and kind of surgery. This study aimed to define the surgical management of paediatric ulcerative colitis and describe attitudes to it among paediatric surgeons.

METHODS

This was a retrospective cohort study. All national gastroenterology units were invited to participate. From January 2009 to December 2013, data on paediatric patients diagnosed with ulcerative colitis that required surgery were collected.

RESULTS

Seven units participated in the study. Seventy-one colectomies were performed (77.3% laparoscopically). Main surgical indications were a severe ulcerative colitis attack (33.8%) and no response to medical therapies (56.3%). A three-stage strategy was chosen in 71% of cases. Straight anastomosis was performed in 14% and J-pouch anastomosis in 86% of cases. A reconstructive laparoscopic approach was used in 58% of patients. Ileo-anal anastomosis was performed by the Knight-Griffen technique in 85.4% and by the pull-through technique in 9.1% of patients. Complications after colectomy, after reconstruction and after stoma closure were reported in 12.7, 19.3 and 35% of cases, respectively.

CONCLUSIONS

This study shows that there is general consensus regarding indications for surgery. The ideal surgical technique remains under debate. Laparoscopy is a procedure widely adopted for colectomy but its use in reconstructive surgery remains limited. Longer follow-up must be planned to define the quality of life of these patients.

Writing and functionalisation of suspended DNA nanowires on superhydrophobic pillar arrays

Nanowire arrays and networks with precisely controlled patterns are very interesting for innovative device concepts in mesoscopic physics. In particular, DNA templates have proven to be versatile for the fabrication of complex structures that obtained functionality via combinations with other materials, for example by functionalisation with molecules or nanoparticles, or by coating with metals. Here, the controlled motion of the a three-phase contact line (TCL) of DNA-loaded drops on superhydrophobic substrates is used to fabricate suspended nanowire arrays. In particular, the deposition of DNA wires is imaged in situ, and different patterns are obtained on hexagonal pillar arrays by controlling the TCL velocity and direction. Robust conductive wires and networks are achieved by coating the wires with a thin layer of gold, and as proof of concept conductivity measurements are performed on single suspended wires. The plastic material of the superhydrophobic pillars ensures electrical isolation from the substrate. The more general versatility of these suspended nanowire networks as functional templates is outlined by fabricating hybrid organic-metal-semiconductor nanowires by growing ZnO nanocrystals onto the metal-coated nanowires.

Hollow plasmonic antennas for broadband SERS spectroscopy

The chemical environment of cells is an extremely complex and multifaceted system that includes many types of proteins, lipids, nucleic acids and various other components. With the final aim of studying these components in detail, we have developed multiband plasmonic antennas, which are suitable for highly sensitive surface enhanced Raman spectroscopy (SERS) and are activated by a wide range of excitation wavelengths. The three-dimensional hollow nanoantennas were produced on an optical resist by a secondary electron lithography approach, generated by fast ion-beam milling on the polymer and then covered with silver in order to obtain plasmonic functionalities. The optical properties of these structures have been studied through finite element analysis simulations that demonstrated the presence of broadband absorption and multiband enhancement due to the unusual geometry of the antennas. The enhancement was confirmed by SERS measurements, which showed a large enhancement of the vibrational features both in the case of resonant excitation and out-of-resonance excitation. Such characteristics indicate that these structures are potential candidates for plasmonic enhancers in multifunctional opto-electronic biosensors.

Consensus guidelines of ECCO/ESPGHAN on the medical management of pediatric Crohn's disease

Children and adolescents with Crohn's disease (CD) present often with a more complicated disease course compared to adult patients. In addition, the potential impact of CD on growth, pubertal and emotional development of patients underlines the need for a specific management strategy of pediatric-onset CD. To develop the first evidenced based and consensus driven guidelines for pediatric-onset CD an expert panel of 33 IBD specialists was formed after an open call within the European Crohn's and Colitis Organisation and the European Society of Pediatric Gastroenterolog, Hepatology and Nutrition. The aim was to base on a thorough review of existing evidence a state of the art guidance on the medical treatment and long term management of children and adolescents with CD, with individualized treatment algorithms based on a benefit-risk analysis according to different clinical scenarios. In children and adolescents who did not have finished their growth, exclusive enteral nutrition (EEN) is the induction therapy of first choice due to its excellent safety profile, preferable over corticosteroids, which are equipotential to induce remission. The majority of patients with pediatric-onset CD require immunomodulator based maintenance therapy. The experts discuss several factors potentially predictive for poor disease outcome (such as severe perianal fistulizing disease, severe stricturing/penetrating disease, severe growth retardation, panenteric disease, persistent severe disease despite adequate induction therapy), which may incite to an anti-TNF-based top down approach. These guidelines are intended to give practical (whenever possible evidence-based) answers to (pediatric) gastroenterologists who take care of children and adolescents with CD; they are not meant to be a rule or legal standard, since many different clinical scenario exist requiring treatment strategies not covered by or different from these guidelines.

Intestinal titres of anti-tissue transglutaminase 2 antibodies correlate positively with mucosal damage degree and inversely with gluten-free diet duration in coeliac disease

It has always been known that anti-tissue transglutaminase 2 (anti-TG2) antibodies are produced in the small intestine. Their serum titres correlate with mucosal damage degree and decrease on a gluten-free diet (GFD). We aimed to correlate intestinal anti-TG2 antibodies levels with degree of mucosal damage and GFD duration. Thirty-four active, 71 potential and 24 CD patients on GFD for at least 2 years were enrolled. Anti-TG2 deposits were detected in intestinal biopsies by double immunofluorescence. Biopsies were cultured for 24 h with medium, and with gliadin peptic tryptic digest (PTG) or A-gliadin peptide 31-43 (P31-43). Anti-TG2 antibodies secreted into supernatants were measured by enzyme-linked immunosorbent assay (ELISA). All active CD patients secreted high titres of anti-TG2 antibodies into culture medium that increased with the worsening of mucosal injury (Spearman's r = 0·71; P < 0·0001). Seventy of 71 potential CD patients and 15 of 24 treated CD patients secreted low titres of anti-TG2 antibodies into supernatants, eight of nine negative treated patients being on GFD for more than 10 years. An inverse correlation between antibody titres and duration of GFD was found, (Spearman's r = -0·52; P < 0·01). All active, 53 of 71 potential and six of 24 treated, CD patients showed anti-TG2 mucosal deposits. Five of six positive treated CD patients had been on GFD for fewer than 6 years and were also positive for secreted anti-TG2. In treated patients, PTG/P31-43 was not able to induce secretion of anti-TG2 antibodies into culture medium. Measurement of anti-TG2 antibodies in biopsy supernatants proved to be more sensitive than detection by immunofluorescence to reveal their intestinal production. Intestinal antiTG2 antibodies titres correlated positively with the degree of mucosal damage and inversely with the duration of GFD.

Controlling wetting and self-assembly dynamics by tailored hydrophobic and oleophobic surfaces

Tailored hydrophobic and oleophobic surfaces are exploited for controlling the wetting behaviour and evaporation process of solution dropped on them. This enables molecules and nano-objects that are dissolved in water or organic solvents to be delivered and arranged in a well-defined 2D layout.

Bio-inspired hybrid microelectrodes: a hybrid solution to improve long-term performance of chronic intracortical implants

The use of implants that allow chronic electrical stimulation and recording in the brain of human patients is currently limited by a series of events that cause the deterioration over time of both the electrode surface and the surrounding tissue. The main reason of failure is the tissue inflammatory reaction that eventually causes neuronal loss and glial encapsulation, resulting in a progressive increase of the electrode-electrolyte impedance. Here, we describe a new method to create bio-inspired electrodes to mimic the mechanical properties and biological composition of the host tissue. This combination has a great potential to increase the implant lifetime by reducing tissue reaction and improving electrical coupling. Our method implies coating the electrode with reprogrammed neural or glial cells encapsulated within a hydrogel layer. We chose fibrin as a hydrogel and primary hippocampal neurons or astrocytes from rat brain as cellular layer. We demonstrate that fibrin coating is highly biocompatible, forms uniform coatings of controllable thickness, does not alter the electrochemical properties of the microelectrode and allows good quality recordings. Moreover, it reduces the amount of host reactive astrocytes – over time – compared to a bare wire and is fully reabsorbed by the surrounding tissue within 7 days after implantation, avoiding the common problem of hydrogels swelling. Both astrocytes and neurons could be successfully grown onto the electrode surface within the fibrin hydrogel without altering the electrochemical properties of the microelectrode. This bio-hybrid device has therefore a good potential to improve the electrical integration at the neuron-electrode interface and support the long-term success of neural prostheses.

3D hollow nanostructures as building blocks for multifunctional plasmonics

We present an advanced and robust technology to realize 3D hollow plasmonic nanostructures which are tunable in size, shape, and layout. The presented architectures offer new and unconventional properties such as the realization of 3D plasmonic hollow nanocavities with high electric field confinement and enhancement, finely structured extinction profiles, and broad band optical absorption. The 3D nature of the devices can overcome intrinsic difficulties related to conventional architectures in a wide range of multidisciplinary applications.

Intestinal anti-tissue transglutaminase antibodies in potential coeliac disease

Anti-tissue transglutaminase 2 (anti-TG2) antibodies are present in the serum of the great majority of untreated coeliac disease (CD) patients. They are produced and deposited in the small intestinal mucosa. Potential CD patients present serum anti-TG2 antibodies higher than cut-off, but a normal duodenal mucosa where mucosal deposits of anti-TG2 are not always detectable. The aim of our work was to investigate the presence of anti-TG2 intestinal antibodies in patients with potential CD, and identify the most sensitive test to detect them. Twelve active CD patients, 28 potential CD patients and 39 non-CD controls were enrolled. Biopsy fragments from all patients were analysed by double immunofluorescence to detect mucosal deposits of anti-TG2 antibodies. Fragments from the same subjects were also cultured for 24 h with medium in the presence or absence of gliadin peptides. Anti-TG2 autoantibodies secreted into supernatants were measured by enzyme-linked immunosorbent assay. All active CD, 68% of potential CD patients and 20% of non-CD controls showed mucosal deposits of immunoglobulin (Ig)A anti-TG2; at the same time 100, 96 and 8% of active CD, potential CD and non-CD control patients secreted these antibodies in culture supernatants, respectively. Our data showed that, to detect intestinal anti-TG2 antibodies, the measurement of antibodies secreted into culture supernatants has higher sensitivity and specificity (97·5 and 92·3%, respectively) than the detection of mucosal deposits (77·5 and 80·0%, respectively). The measurement of intestinal anti-TG2 antibodies may prove useful in clinical practice to predict evolution towards mucosal atrophy in potential coeliac patients and identify patients with gluten sensitivity.

Nanoparticle-based delivery of small interfering RNA: challenges for cancer therapy

During recent decades there have been remarkable advances and profound changes in cancer therapy. Many therapeutic strategies learned at the bench, including monoclonal antibodies and small molecule inhibitors, have been used at the bedside, leading to important successes. One of the most important advances in biology has been the discovery that small interfering RNA (siRNA) is able to regulate the expression of genes, by a phenomenon known as RNA interference (RNAi). RNAi is one of the most rapidly growing fields of research in biology and therapeutics. Much research effort has gone into the application of this new discovery in the treatment of various diseases, including cancer. However, even though these molecules may have potential and strong utility, some limitations make their clinical application difficult, including delivery problems, side effects due to off-target actions, disturbance of physiological functions of the cellular machinery involved in gene silencing, and induction of the innate immune response. Many researchers have attempted to overcome these limitations and to improve the safety of potential RNAi-based therapeutics. Nanoparticles, which are nanostructured entities with tunable size, shape, and surface, as well as biological behavior, provide an ideal opportunity to modify current treatment regimens in a substantial way. These nanoparticles could be designed to surmount one or more of the barriers encountered by siRNA. Nanoparticle drug formulations afford the chance to improve drug bioavailability, exploiting superior tissue permeability, payload protection, and the “stealth” features of these entities. The main aims of this review are: to explain the siRNA mechanism with regard to potential applications in siRNA-based cancer therapy; to discuss the possible usefulness of nanoparticle-based delivery of certain molecules for overcoming present therapeutic limitations; to review the ongoing relevant clinical research with its pitfalls and promises; and to evaluate critically future perspectives and challenges in siRNA-based cancer therapy.

Blue rubber bleb nevus: an uncommon cause of intestinal intussusception

The blue rubber bleb nevus syndrome or Bean syndrome is a rare disorder characterized by cutaneous and gastrointestinal vascular malformations. A 5-year-old girl with Bean syndrome hospitalized in a pediatric unit came under our observation with abdominal pain and vomiting. An X-ray of the abdomen showed an intestinal occlusion and an ultrasonography showed a suspected intestinal invagination. She underwent emergency laparoscopic surgery using three trocars. Laparoscopy revealed a huge ascitis and multiple vascular lesions located on the loops and on the parietal peritoneum, and we identified also an ileo-ileal invagination. We performed a laparoscopic disinvagination that showed one huge vascular lesion producing the invagination and causing a stenosis of intestinal lumen. We performed an intestinal resection after exteriorizing the loops through the umbilicus as well as a termino-terminal ileal anastomosis.

CONCLUSIONS

Our case shows that an intestinal invagination due to Bean syndrome is extremely rare in pediatric patients but possible. In the emergency, laparoscopy seems to be a safe and effective procedure to confirm the diagnosis and to perform the disinvagination mini-invasivally. In addition, laparoscopy permits to have a clear picture of other intra-abdominal lesions linked to Bean syndrome.

Impact of antisecretory treatment on respiratory symptoms of gastroesophageal reflux disease in children

The effect of antisecretory treatment on extraesophageal symptoms of gastroesophageal reflux disease was evaluated. Seventy-eight children presenting with typical and extraesophageal symptoms of gastroesophageal reflux disease underwent a multichannel intraluminal impedance and pH monitoring (MII/pH). Children with a positive MII/pH were randomly treated with proton pump inhibitors (PPIs) or histamine H(2) -receptor antagonists (H(2) RAs) during 3 months. At the end of the treatment period, all patients were recalled. A second treatment period of 3 months was given to those patients who were not symptom-free after 3 months. Thirty-five of the forty-one (85.4%) children with a pathologic MII/pH presented with extraesophageal symptoms and were treated with PPIs (omeprazole; n:19) or H(2) RAs (ranitidine; n:16) for 12 weeks. After 3 months, 11/19 (57.9%) PPI-treated patients had a complete resolution of symptoms; 6/8 nonresponders were treated with PPI for another 3 months and became all symptom-free. The other two underwent a Nissen fundoplication. Only 5/16 (31.2 %) patients treated with H(2) RAs had a complete resolution of symptoms after 3 months; 1/11 was treated again with H(2) RAs during 3 months, and 10/11 were changed to PPIs. In 3/10, a partial resolution of symptoms was achieved, while in 7/10, a complete remission was obtained (P < 0.05). Antisecretory reflux treatment improves extraesophageal reflux symptoms. The efficacy of PPIs is superior to that of H(2) RAs in these children.

The association of coeliac disease in childhood with functional gastrointestinal disorders: a prospective study in patients fulfilling Rome III criteria

BACKGROUND

An association between coeliac disease (CD) and functional gastrointestinal disorders (FGIDs) has at present only been demonstrated in adults.

AIMS

To assess the prevalence of FGIDs at 1 year and the role of psychological aspects on the development of FGIDs in CD children.

METHODS

One-hundred consecutive CD children (36M and 64F) were followed up for 1 year. Fifty-six children (25M and 31F) represented the control group. All children and/or their parents completed validated questionnaires for GI symptoms, depression, and anxiety. GI symptoms at diagnosis and after 1 year of gluten-free diet (GFD) were compared.

RESULTS

Twenty-three/82 (28%) CD patients followed up prospectively, on GFD from at least 1 year, fulfilled the Rome III criteria for FGIDs compared with 5/56 (8.9%) controls (P = 0.008; χ² = 6.8; OR: 3.97; 95% CI: 1.40-11.21). Children complaining with GI symptoms alone [21/52 (40.3%)] more likely fulfilled Rome III criteria for FGIDs after 1 year of GFD than children with extra-intestinal symptoms (P = 0.045). CD children with FGDIs presented significantly higher anxiety and depression compared to CD children without FGIDs and controls (P = 0.02).

CONCLUSIONS

This study demonstrates that children with CD on a GFD for a year have a much higher prevalence of functional GI symptoms than do controls. Whether the risk is due to the residua of a chronic inflammatory process, and/or due to psychological factors remains to be further tested.

Impact of the Rome II paediatric criteria on the appropriateness of the upper and lower gastrointestinal endoscopy in children

BACKGROUND

The demand for paediatric gastrointestinal (GI) endoscopy has increased, resulting in a significant rise of overall costs.

AIM

To assess the clinical impact of the Rome II criteria for functional gastrointestinal disorders when selecting paediatric patients who underwent GI endoscopy.

METHODS

The indications and findings of GI endoscopic procedures performed before and after the publication of the Rome II criteria were evaluated retrospectively.

RESULTS

Upper GI endoscopy was performed in 1124 children, whereas colonoscopy was performed in 500 subjects. A total of 607 (54%) oesophago-gastro-duodenoscopies (OGDs) were positive and 517 (46%) were negative, whereas 306 (61.1%) colonoscopies were positive and 194 (38.9%) were negative. Of the 1624 procedures, 26% were considered inappropriate according to the Rome II criteria. Inappropriate procedures decreased significantly after publication of the Rome II criteria (OR, 3.7; 95% CI, 1.8-7.5). Of 1202 appropriate GI endoscopies, 502 OGD (62.7%) were significantly contributive, compared with only 105 (32.5%) of the 323 inappropriate procedures (OR, 3.5; 95% CI, 2.6-4.6), whereas 265 (65.8%) colonoscopies were significantly contributive, compared with only 41 (42.3%) of the 97 inappropriate procedures (OR, 2.6; 95% CI, 1.6-4.1).

CONCLUSIONS

The use of the criteria for functional gastrointestinal disorders makes a significant positive impact, they should reduce unnecessary paediatric GI endoscopy.

Blue rubber bleb nevus syndrome

Blue Rubber Bleb Nevus Syndrome (BRBNS) is a rare condition characterized by multiple venous malformations involving the skin and internal organs. The gastrointestinal tract is always involved and intestinal haemorrhage is the most frequent clinical manifestation associated with iron deficiency anaemia. We describe a 10-year-old girl who, since birth, presented numerous venous malformations all over her body and a lymphangioma in the right leg. At the age of 5 years, she also had a severe episode of gastric bleeding requiring a blood transfusion. From this episode, she is suffering from chronic anaemia and this is the reason for admission into our hospital. The endoscopic examination of the gastrointestinal tract revealed multiple giant venous malformations in the oesophagus, stomach, duodenum and in all visible sections of the colon. Endoscopy is the gold standard technique for the diagnosis of BRBNS with GI lesions and also allows immediate therapeutic measures such as argon plasma coagulation, laser photocoagulation, sclerotherapy or band ligation. In addition, pharmacological treatments based on corticosteroids, interferon alfa, vincristine or octreotide have been described for BRBNS.

CONCLUSION

Blue Rubber Bleb Nevus Syndrome is a congenital cutaneous and gastrointestinal haemangiomatosis. Its morbidity and mortality depends on involvement of visceral organs and particularly on GI bleeding. The treatment is based on pharmacological or surgical therapy. Overall, the most important step is the follow-up to the presence and the evolution of GI lesions and the possible bleeding.

Proton pump inhibitors as a risk factor for paediatric Clostridium difficile infection

BACKGROUND

Proton pump inhibitors (PPIs) and H(2) receptor antagonists (H(2)RAs) may play an important role on the onset of Clostridium difficile-associated disease (CDAD) in adults. The impact of Clostridium difficile on children treated with gastric acid-suppressing agents remains unknown.

AIM

To investigate the relationship between CDAD and exposure to acid suppressive therapy in hospitalized paediatric patients.

METHODS

We reviewed the medical records of children, with a diagnosis of protracted diarrhoea and abdominal pain, whose stool was analysed for C. difficile toxins. We identified 68 patients with CDAD. For each patient, we randomly selected one control subjects with stool analysis negative for C. difficile. Comorbid illnesses, previous hospitalizations, antibiotics, corticosteroids, immunosuppressants and gastric acid suppressing exposures were recorded.

RESULTS

The use of PPI was significantly higher in C. difficile positive group compared with C. difficile negative group [odds ratio (OR): = 4.5; 95% confidence interval (CI) = 1.4-14.4]. We also found a trend for the use of H(2)RAs in patients infected by C. difficile compared with C. difficile negative comparison group (OR: = 3.8; 95% CI = 0.7-18.9).

CONCLUSIONS

Children exposed to PPIs therapy seem to be at higher risk for the development of Clostridium difficile-associated disease.

Irritable bowel syndrome in childhood: visceral hypersensitivity and psychosocial aspects

Visceral hypersensitivity is often considered to play a major etiologic role in the pathophysiology of irritable bowel syndrome in adults, and some authors argue that this increased sensitivity is mainly due to psychological factors. In contrast, there are no data in children with irritable bowel syndrome which confirm this relationship. The aim of the study was to evaluate the relationship between psychosocial aspects and sensorymotor function in children affected by irritable bowel syndrome. Ten children fulfilling the Rome II criteria for irritable bowel syndrome and seven healthy controls were enrolled. We studied the thresholds and the perception of visceral stimuli in the rectum by means of an electronic barostat (isobaric phasic distentions, 3 mmHg/1 min, interval 1 min) and a validated questionnaire. Personality features were evaluated by means of the Big Five Questionnaire for Children. Sleep, mood disturbance, anxiety and individual performance (missed school days, school results and social activities) were also evaluated. Children with irritable bowel syndrome showed significantly lower thresholds for discomfort (14.8 +/- 3.5 vs 22.3 +/- 6.9 mmHg, P = 0.010) and a higher cumulative perception score (28.2 +/- 11.1 vs 12.3 +/- 8.0, P = 0.005) compared with healthy controls. A higher emotional instability (57.8 +/- 7.0 vs 48.7 +/- 10.1, P = 0.047), sleep disturbance (7.2 +/- 1.0 vs 9.3 +/- 0.5, P = 0.004) and anxiety (6.3 +/- 2.0 vs 2.3 +/- 1.7, P = 0.009) were observed in irritable bowel syndrome patients. Moreover, in a multivariate analysis, the cumulative perception score was significantly related to emotional instability (P = 0.042). In conclusion children with irritable bowel syndrome exhibit visceral hypersensitivity and psychosocial impairment. Emotional instability, as a personality feature in these children, seems to modulate the perception response to visceral stimulations.

Albumin-bound formulation of paclitaxel (Abraxane ABI-007) in the treatment of breast cancer

Breast cancer is the most common type of malignancy diagnosed in women. In the metastatic setting this disease is still uncurable. Taxanes represent an important class of antitumor agents which have proven to be fundamental in the treatment of advanced and early-stage breast cancer, but the clinical advances of taxanes have been limited by their highly hydrophobic molecular status. To overcome this poor water solubility, lipid-based solvents have been used as a vehicle, and new systemic formulations have been developed, mostly for paclitaxel, which are Cremophor-free and increase the circulation time of the drug. ABI-007 is a novel, albumin-bound, 130-nm particle formulation of paclitaxel, free from any kind of solvent. It has been demonstrated to be superior to an equitoxic dose of standard paclitaxel with a significantly lower incidence of toxicities in a large, international, randomized phase III trial. The availability of new drugs, such as Abraxane, in association with other traditional and non-traditional drugs (new antineoplastic agents and targeted molecules), will give the oncologist many different effective treatment options for patients in this setting.

Prevalence of atopy in children with chronic constipation

OBJECTIVES

To evaluate the prevalence of chronic constipation (CC) in unselected children, its association with atopy and the efficacy of a cow's milk protein (CMP) elimination diet on refractory constipation.

STUDY DESIGN

The study was conducted by six primary care paediatricians, serving a population of 5113 children aged from birth through to 12 years; only 2068 children were 6 months to 6 years. During a 3-month period, prevalence of CC was determined for the entire study population, ages 0-12 years. In the second part of the study, all patients aged 6 months to 6 years with CC, and age- and sex-matched controls, were evaluated for atopy and its association with CC. A questionnaire was completed including personal and family history of atopy and bowel-movement characteristics. Patients were tested for atopy by specific serum IgE and/or skin-prick tests. Constipated patients, refractory to osmotic laxatives, underwent a 4-week CMP elimination diet.

RESULTS

91 (1.8%) children had CC, and 69 (3.3%) of the 6 months to 6 years age group fell into the atopy study age range. All 69 constipated children (mean age 34.9 (18.0) months) and 69 controls completed the questionnaire. Twelve of the 69 constipated children (17.3%) and 13 out of the 69 control children (18.8%) had a diagnosis of atopy. Eleven out of 69 (15.9%) constipated children were refractory to constipation treatment, and three (27.3%) of these had atopy. The 4-week trial of dietary elimination did not result in improvement in any of these 11 children.

CONCLUSIONS

In our study group, prevalence of atopy among children with CC is similar to that in the general population. The level of refraction of CC does not seem to be related to cow's milk allergy.