Efficacy and safety of methylphenidate on attention deficit hyperactivity disorder in children with Down syndrome.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is a common co-morbidity that affects up to 44% of children with Down syndrome (DS). There is a need for reliable, good quality research on the use of methylphenidate within this population. The objective of this study is to report our experience regarding the management of ADHD in these children using methylphenidate. METHODS: This study is a retrospective observation of 21 children with DS, followed at Jérôme Lejeune Institute between 2000 and 2018. The diagnosis of ADHD was made using the Diagnostic and Statistical Manual of Mental Disorders criteria. Efficacy was measured as response or non-response on two main symptoms: attention/concentration and hyperactivity/impulsivity. Safety was evaluated by the presence or absence of side effects. RESULTS: Sixteen out of the 21 children (76%) showed improvement with methylphenidate. The average age of treatment onset in responding children was 8 years and 10 months versus 6 years and 3 months in non-responders (P = 0.05). Average dose/weight was significantly different in responders and non-responders (0.82 vs. 0.54 mg/kg/day, respectively; P = 0.03). Twelve children out of 21 (57%) experienced side effects; only three experienced side effects severe enough to require treatment interruption. Most common side effects were loss of appetite and difficulties in falling asleep. CONCLUSION: Methylphenidate was effective and safe in treating ADHD in 76% of cases in children with DS, with few serious side effects to report. Early diagnosis of ADHD is important to improve the quality of life, learning, inclusion and socialisation of children with DS.

Feeding problems and gastrointestinal diseases in Down syndrome.

BACKGROUND AND METHOD: Feeding problems and gastrointestinal disorders are the most common anomalies in people with Down syndrome (DS) and have a significant impact on their daily life. This study lists the various anomalies on the basis of 504 references selected from a PubMed search in October 2018. RESULTS: The anomalies are grouped into three categories: anatomical anomalies: duodenal atresia and stenosis (3.9%), duodenal web and annular pancreas; aberrant right subclavian artery (12% of children with DS with cardiac anomaly); Hirschsprung's disease (2.76%); anorectal malformation (1.16%); congenital vascular malformations of the liver; orofacial cleft, bifid uvula (4.63%), and submucous orofacial cleft; esophageal atresia (0.5-0.9%); pyloric stenosis (0.3%); diaphragmatic hernia; malrotation of small intestine or duodenum inversum; omphalocele, gastroschisis or anomalies of the median line, anomalies of the umbilical vein; biological, immunological, and infectious anomalies: neonatal cholestasis (3.9%); neonatal hepatic fibrosis; Helicobacter pylori infection (75.8% in institutionalized children with DS, between 29.2 and 19.5% in non-institutionalized); non-alcoholic fatty liver disease (NAFLD; 82% in obese and 45% in non-obese); biliary lithiasis (6.9% under 3 years); celiac disease (6.,6%); geographical tongue (4%); hepatitis B virus sensitivity; autoimmune hepatitis and cholangitis; Crohn's disease, inflammatory bowel disease (IBD); pancreatitis; vitamin D deficiency (45.2% in Italy); functional disorders: suction, swallowing and chewing disorders (13 of 19 children with DS under 4 years); gastroesophageal reflux (47% in children with sleep apnea); achalasia (0,5% in adults); obesity (51.6% of males and 40.0% of females in Ireland) and overweight (32.0% and 14.8%); constipation (19.0%). Based on their practice, the authors insist on the following points: malformations are sometimes detected late (chronic vomiting after the introduction of food pieces, resistant constipation despite appropriate measures); prescription of preventive doses of vitamin D is advised; jaundice in a baby with DS may be retentional; in the event of transient leukemoid reaction it is vital to monitor liver function; the patient with geographic tongue must be reassured; for celiac serology there is no consensus on the staring age and the frequency, we propose every year from the age of 2; we advise to test people with DS for H. pylori infection if they are attending specialized institutions; abdominal ultrasounds must be systematic during the first months of life; detection of NAFLD is recommended; people with DS must be vaccinated against hepatitis B; breastfeeding is possible with maternal support; it is important to start speech therapy very early; feeding difficulties are often overlooked by the family and educators; gastroesophageal reflux is often pathological; preventing obesity must start from birth using body mass index for the general population; it is necessary to do everything for their meals to be joyful.

DNA self-assembly-driven positioning of molecular components on nanopatterned surfaces.

We present a method for the specific, spatially targeted attachment of DNA molecules to lithographically patterned gold surfaces-demonstrated by bridging DNA strands across nanogap electrode structures. An alkanethiol self-assembled monolayer was employed as a molecular resist, which could be selectively removed via electrochemical desorption, allowing the binding of thiolated DNA anchoring oligonucleotides to each electrode. After introducing a bridging DNA molecule with single-stranded ends complementary to the electrode-tethered anchoring oligonucleotides, the positioning of the DNA molecule across the electrode gap, driven by self-assembly, occurred autonomously. This demonstrates control of molecule positioning with resolution limited only by the underlying patterned structure, does not require any alignment, is carried out entirely under biologically compatible conditions, and is scalable.

Label-free electrochemical impedance biosensor to detect human interleukin-8 in serum with sub-pg/ml sensitivity.

Biosensors with high sensitivity and short time-to-result that are capable of detecting biomarkers in body fluids such as serum are an important prerequisite for early diagnostics in modern healthcare provision. Here, we report the development of an electrochemical impedance-based sensor for the detection in serum of human interleukin-8 (IL-8), a pro-angiogenic chemokine implicated in a wide range of inflammatory diseases. The sensor employs a small and robust synthetic non-antibody capture protein based on a cystatin scaffold that displays high affinity for human IL-8 with a KD of 35 ± 10 nM and excellent ligand specificity. The change in the phase of the electrochemical impedance from the serum baseline, ∆θ(ƒ), measured at 0.1 Hz, was used as the measure for quantifying IL-8 concentration in the fluid. Optimal sensor signal was observed after 15 min incubation, and the sensor exhibited a linear response versus logarithm of IL-8 concentration from 900 fg/ml to 900 ng/ml. A detection limit of around 90 fg/ml, which is significantly lower than the basal clinical levels of 5-10 pg/ml, was observed. Our results are significant for the development of point-of-care and early diagnostics where high sensitivity and short time-to-results are essential.

Antibody mimetic receptor proteins for label-free biosensors.

The development of high sensitivity biosensors, for example for clinical diagnostics, requires the identification of suitable receptor molecules which offer high stability, specificity and affinity, even when embedded into solid-state biosensor transducers. Here, we present an electrochemical biosensor employing small synthetic receptor proteins (Mw < 15 kDa) which emulate antibodies but with improved stability, sensitivity and molecular recognition properties, in particular when immobilized on a solid sensor surface. The synthetic receptor protein is a non-antibody-based protein scaffold with variable peptide regions inserted to provide the specific binding, and was designed to bind anti-myc tag antibody (Mw ∼ 150 kDa), as a proof-of-principle exemplar. Both the scaffold and the selected receptor protein were found to have high thermostability with melting temperatures of 101 °C and 85 °C, respectively. Furthermore, the secondary structures of the receptor protein were found to be very similar to that of the original native scaffold, despite the insertion of variable peptide loops that create the binding sites. A label-free electrochemical sensor was fabricated by functionalising a microfabricated gold electrode with the receptor protein. A change in the phase of the electrochemical impedance was observed when the biosensor was subjected to anti-myc tag antibodies at concentrations between 6.7 pM and 6.7 nM. These findings demonstrate that these non-antibody receptor proteins are excellent candidates for recognition molecules in label-free biosensors.

Fabrication and characterization of gold nano-wires templated on virus-like arrays of tobacco mosaic virus coat proteins.

The rod-shaped plant virus tobacco mosaic virus (TMV) is widely used as a nano-fabrication template, and chimeric peptide expression on its major coat protein has extended its potential applications. Here we describe a simple bacterial expression system for production and rapid purification of recombinant chimeric TMV coat protein carrying C-terminal peptide tags. These proteins do not bind TMV RNA or form disks at pH 7. However, they retain the ability to self-assemble into virus-like arrays at acidic pH. C-terminal peptide tags in such arrays are exposed on the protein surface, allowing interaction with target species. We have utilized a C-terminal His-tag to create virus coat protein-templated nano-rods able to bind gold nanoparticles uniformly. These can be transformed into gold nano-wires by deposition of additional gold atoms from solution, followed by thermal annealing. The resistivity of a typical annealed wire created by this approach is significantly less than values reported for other nano-wires made using different bio-templates. This expression construct is therefore a useful additional tool for the creation of chimeric TMV-like nano-rods for bio-templating.

Nanoscale programmable sequence-specific patterning of DNA scaffolds using RecA protein.

Molecular self-assembly inherent to many biological molecules, in conjunction with suitable molecular scaffolds to facilitate programmable positioning of nanoscale objects, offers a promising approach for the integration of functional nanoscale complexes into macroscopic host devices. Here, we report the use of the protein RecA as a means of highly efficient programmable patterning of double-stranded (ds)DNA molecules with molecular-scale precision at specific locations along the DNA strand. RecA proteins form nucleoprotein filaments with single-stranded (ss)DNA molecules, which are chosen to be of sequence homologous to the desired binding region on the dsDNA scaffold. We show that the patterning yield can be in excess of 85% and we demonstrate that concurrent patterning of multiple locations on the same dsDNA scaffold can be achieved with separation between the assembled nucleoprotein filaments of less than 4 nm. This is an important prerequisite for this programmable and flexible DNA scaffold patterning technique to be employed in molecular- and nanoscale assembly applications.

The implementation of the 'International Classification of Functioning, Disability and Health' (ICF) in daily practice of neurorehabilitation: an interdisciplinary project at the Kantonsspital of Lucerne, Switzerland.

PURPOSE: The current paper describes the implementation of ICF as a standard language and framework for description of human functioning and disability for common use in every day work by the multiprofessional team. METHOD: An interdisciplinary project team involving all rehabilitation specialities was constituted. The extensive original document of ICF was broken down to a simplified raster for body functions and structures, activities and participation, as well as for contextual factors. These rasters had to cover the most important aspects concerning the patients treated on our unit. Checklists on the basis of these rasters were worked out for use by the different specialized teams. Using these checklists, rehabilitation conferences, form and language of interdisciplinary communication, goal setting and documentation were introduced newly in every day work for the interdisciplinary rehabilitation team, structured strictly based on the ICF-criteria. RESULTS: Since April 2002 the ICF-based processes are implemented in routine work for all members of the rehabilitation staff. First experiences show good acceptance by the team members, improvements in communication and documentation as well as substantial gains in content and handling of rehabilitation conferences. As a result of the implementation we observed, that participation, context and domiciliary interventions gained quite more influence in every day work at the unit. CONCLUSION: Implementation improved considerably the quality of interdisciplinary work processes and contributed to a more systematic approach to rehabilitation tasks by the team members.

Dielectrophoretic manipulation of surface-bound DNA.

Dielectrophoretic manipulation enables the positioning and orientation of DNA molecules for nanometer-scale applications. However, the dependence of the dielectrophoretic force and torque on the electric field magnitude and frequency has to be well characterised to realise fully the potential of this technique. DNA in solution is attracted to the strongest electric field gradient (i.e. the electrode edge) as a result of the dielectrophoretic force, while the dielectrophoretic torque aligns the DNA with its longest axis parallel to the electric field. In this work, the authors attached -DNA fragments (48 and 25 kilobases) to an array of gold microelectrodes via a terminal thiol bond and characterised the orientation and elongation as a function of electric field magnitude (0.1-0.8 MVm) and frequency (0.08-1.1 MHz). Maximum elongation was observed between 200 and 500 kHz for the attached DNA. Dielectrophoresis is limited by thermal randomisation at electric fields below 0.1 MVm and by electrothermal effects above 0.7 MVm. The authors conclude that dielectrophoresis can be used to manipulate surface-immobilised DNA reproducibly.

Spectroscopic evidence for unconventional superconductivity in UBe13

We report on measurements of the differential conductivity G of UBe13-Au contacts, which reveal the existence of low-energy Andreev surface bound states. These bound states are identified via huge conductance peaks at zero bias that may form only in superconductors with nontrivial energy-gap functions. From the voltage dependence of G at T6.7, much in excess of the weak coupling BCS value of 3.5, and directly indicating strong coupling effects in superconducting UBe13.