Neurocognitive effects and electrophysiological findings in ADHD and self-limiting centrotemporal spike wave epilepsy (SeLECTS) - A prospective tertiary care study.

OBJECTIVE: The study aimed to determine the prevalence of attention deficit hyperactivity disorder (ADHD) in patients with self-limiting epilepsy with centrotemporal spike wave (SeLECTS), as well as the electroclinical features associated with this comorbid condition and the neurocognitive effects using psychometric tests. Additionally, we analysed the electrophysiological findings and neurocognitive status of patients with ADHD to estimate the prevalence of epilepsy and neurocognitive effects in the ADHD population and evaluate their clinical features. METHOD: The study included patients diagnosed with SeLECT and ADHD who were matched for age and gender. Electrophysiological tests, psychometric tests, demographic and clinical characteristics of SeLECTS patients aged 7-13 years and ADHD patients of similar age were analysed. The study examined electrophysiological and psychometric tests, as well as demographic and clinical characteristics. Both groups underwent testing using the Wechsler Intelligence Scale for Children (WISC-R), Stroop Colour and Word Test (SCWT), and EEG (Electroencephalogram). The SeLECT group also underwent the Bender Visual-Motor Gestalt Test. RSULTS: No significant relationship was found between the SeLECT and ADHD groups in terms of age and gender. The rate of epileptiform discharge in EEG findings without a diagnosis of epilepsy was 5.6 % (n = 2) in the ADHD group. The rate of ADHD in the SeLECTS group was 28 % (n = 11). Although all subsections of the WISCR test were higher in the ADHD patient group than in the SeLECTS patient group, only verbal IQ and total IQ showed a significant difference. No significant differences were found between the completion times, error rates, and correction averages of the SCWT sections in both groups. There was no significant correlation found between the performance IQ, verbal IQ, and total intelligence scores in either the isolated SeLECTS patient group or the SeLECTS + ADHD patient group (p > 0.05). However, it is worth noting that verbal IQ was below normal in both groups and slightly lower in the SeLECT + ADHD group. Additionally, the mean SeWT completion time was significantly longer in the SeLECT + ADHD group than in the isolated SeLECT group. However, no significant difference was found in the Bender Gestalt Visual Motor Perception Test. In the psychometric analyses comparing the isolated SeLECTS, SeLECT + ADHD, and ADHD patient groups, the SCWT completion times were significantly longer in the SeLECT + ADHD group than in the other two groups. The verbal IQ score was significantly higher in the ADHD group than in the other two groups. CONCLUSION: In conclusion, although SeLECTS is commonly considered a benign form of epilepsy, our study found a high rate of comorbidity with ADHD. This condition has a negative impact on verbal intelligence and sustained attention, highlighting the importance of a complete neuropsychological evaluation at the stage of epilepsy diagnosis. It is crucial not to overlook the possibility of an ADHD diagnosis.

Platform for in situ real-time measurement of protein-induced conformational changes of DNA.

A platform for in situ and real-time measurement of protein-induced conformational changes in dsDNA is presented. We combine electrical orientation of surface-bound dsDNA probes with an optical technique to measure the kinetics of DNA conformational changes. The sequence-specific Escherichia coli integration host factor is utilized to demonstrate protein-induced bending upon binding of integration host factor to dsDNA probes. The effects of probe surface density on binding/bending kinetics are investigated. The platform can accommodate individual spots of microarrayed dsDNA on individually controlled, lithographically designed electrodes, making it amenable for use as a high throughput assay.

TATA binding proteins can recognize nontraditional DNA sequences.

We demonstrate an accurate, quantitative, and label-free optical technology for high-throughput studies of receptor-ligand interactions, and apply it to TATA binding protein (TBP) interactions with oligonucleotides. We present a simple method to prepare single-stranded and double-stranded DNA microarrays with comparable surface density, ensuring an accurate comparison of TBP activity with both types of DNA. In particular, we find that TBP binds tightly to single-stranded DNA, especially to stretches of polythymine (poly-T), as well as to the traditional TATA box. We further investigate the correlation of TBP activity with various lengths of DNA and find that the number of TBPs bound to DNA increases >7-fold as the oligomer length increases from 9 to 40. Finally, we perform a full human genome analysis and discover that 35.5% of human promoters have poly-T stretches. In summary, we report, for the first time to our knowledge, the activity of TBP with poly-T stretches by presenting an elegant stepwise analysis of multiple techniques: discovery by a novel quantitative detection of microarrays, confirmation by a traditional gel electrophoresis, and a full genome prediction with computational analyses.

Direct observation of conformation of a polymeric coating with implications in microarray applications.

The conformation of a three-dimensional polymeric coating (copoly(DMA-NAS-MAPS)) and immobilization and hybridization of DNA strands on the polymer coated surface are investigated. A conformational change, specifically the swelling of the surface adsorbed polymer upon hydration, is quantified in conjunction with the application of this polymer coating for DNA microarray applications. Fluorescently labeled short DNA strands (23mers) covalently linked to the functional groups on the adsorbed polymer are used as probes to measure the swelling of the polymer. A fluorescence microscopy technique, Spectral Self-Interference Fluorescence Microscopy (SSFM), is utilized to directly measure the change in axial position of fluorophores due to swelling with subnanometer accuracy. Additionally, immobilization characteristics of single stranded DNA (ssDNA) and double stranded DNA (dsDNA) probes, as well as hybridization of ssDNA with target strands have been studied. The results show that ssDNA further away from the surface is hybridized more efficiently, which strengthens the earlier analysis of this polymeric coating as a simple but highly efficient and robust DNA microarray surface chemistry.

Resonant Cavity Imaging: A Means Toward High-Throughput Label-Free Protein Detection.

The resonant cavity imaging biosensor (RCIB) is an optical technique for detecting molecular binding interactions label free at many locations in parallel that employs an optical resonant cavity for high sensitivity. Near-infrared light centered at 1512.5 nm couples resonantly through a Fabry-Perot cavity constructed from dielectric reflectors (Si/SiO(2)), one of which serves as the binding surface. As the wavelength is swept using a tunable laser, a near-infrared digital camera monitors cavity transmittance at each pixel. A wavelength shift in the local resonant response of the optical cavity indicates binding. Positioning the sensing surface with respect to the standing wave pattern of the electric field within the cavity controls the sensitivity with which the presence of bound molecules is detected. Transmitted intensity at thousands of pixel locations is recorded simultaneously in a 10 s, 5 nm scan. An initial proof-of-principle setup has been constructed. A test sample was fabricated with 25, 100-mum wide square features, each with a different density of 1-mum square depressions etched 12 nm into the SiO(2) surface. The average depth of each etched region was found with 0.05 nm rms precision. In a second test, avidin, bound selectively to biotin conjugated bovine serum albumin, was detected.

Analytical technologies for integrated single-cell analysis of human immune responses.

The immune system is a network of cells in which the constitutive members interact through dense and sometimes overlapping connections. The extreme complexity of this network poses a significant challenge for monitoring pathological conditions (e.g., food allergies, autoimmunity, and other chronic inflammatory diseases) and for discovering robust signatures of immunological responses that correlate with or predict the efficacy of interventions. The diversity among immune cells found in clinical samples (variations in cellular functions, lineages, and clonotypic breadth) requires approaches for monitoring immune responses with single-cell resolution.In this chapter, we present an engineering approach for integrated single-cell analysis that uses interchangeable modular operations to provide a comprehensive characterization of the phenotypic, functional, and genetic variations for individual cells. We focus on the use of microfabricated devices to isolate and interrogate single cells, and on the analytical components that enable subsequent detection, correlation, and interpretation of multidimensional sets of data. We discuss specific challenges and opportunities in the realization of this concept, and review two examples where it has been implemented. The presented approach should provide a basis for the design and implementation of nonconventional bioanalytical processes for studying specific responses of an immune system.

Label-free microarray imaging for direct detection of DNA hybridization and single-nucleotide mismatches.

A novel method is proposed for direct detection of DNA hybridization on microarrays. Optical interferometry is used for label-free sensing of biomolecular accumulation on glass surfaces, enabling dynamic detection of interactions. Capabilities of the presented method are demonstrated by high-throughput sensing of solid-phase hybridization of oligonucleotides. Hybridization of surface immobilized probes with 20 base pair-long target oligonucleotides was detected by comparing the label-free microarray images taken before and after hybridization. Through dynamic data acquisition during denaturation by washing the sample with low ionic concentration buffer, melting of duplexes with a single-nucleotide mismatch was distinguished from perfectly matching duplexes with high confidence interval (>97%). The presented technique is simple, robust, and accurate, and eliminates the need of using labels or secondary reagents to monitor the oligonucleotide hybridization.

Quantification of DNA and protein adsorption by optical phase shift.

A primary advantage of label-free detection methods over fluorescent measurements is its quantitative detection capability, since an absolute measure of adsorbed material facilitates kinetic characterization of biomolecular interactions. Interferometric techniques relate the optical phase to biomolecular layer density on the surface, but the conversion factor has not previously been accurately determined. We present a calibration method for phase shift measurements and apply it to surface-bound bovine serum albumin, immunoglobulin G, and single-stranded DNA. Biomolecules with known concentrations dissolved in salt-free water were spotted with precise volumes on the array surface and upon evaporation of the water, left a readily calculated mass. Using our label-free technique, the calculated mass of the biolayer was compared with the measured thickness, and we observed a linear dependence over 4 orders of magnitude. We determined that the widely accepted conversion of 1 nm of thickness corresponds to approximately 1 ng/mm(2) surface density held reasonably well for these substances and through our experiments can now be further specified for different types of biomolecules. Through accurate calibration of the dependence of thickness on surface density, we have established a relation allowing precise determination of the absolute number of molecules for single-stranded DNA and two different proteins.