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A compact organic electrochemical transistors (OECT) sensor enriched with carbon quantum dots (CQDs) was developed to enhance the transconductance of an electropolymerized poly(3,4-ethylenedioxythiophene) (PEDOT) film, enabling the precise and selective detection of dopamine (DA). Accurate monitoring of DA levels is critical for diagnosing and managing related conditions. Incorporating CQDs, we have achieved a remarkable up to threefold increase in current at the DA detection peak in differential pulse voltammetry. This enhancement showcases superior selectivity even in the presence of high concentrations of interferents like uric acid and ascorbic acid. This material significantly boosts the sensitivity of OECTs for DA detection, delivering an amperometric response with a detection limit of 55 nM and a broader detection range (1 - 500 µM). Our results underscore the potential of low-dimensional carbonaceous materials in creating cost-effective, high-sensitivity devices for detecting DA and other biomolecules. This breakthrough sets the stage for the development of next-generation biosensors for point-of-care diagnostics., (© 2024. The Author(s).)

Cerebral ischemic stroke has a significant mortality rate and persistent impairment. The initial diagnosis of stroke occurs by magnetic resonance imaging and computed tomography. There is a strong need for more accessible, less expensive, and non-invasive methods besides the neuroimaging methods. MicroRNAs (miRNAs) are critical regulators for ischemic stroke as they are involved in stroke pathophysiology. The goal of the current study was to determine whether microRNA-221 (miR-221) could be used as a diagnostic biomarker for patients with ischemic stroke, and whether it can serve as a promising indicator of the disease severity especially if combined with interleukin-6 (IL-6). The study included 90 subjects, 45 cerebral ischemic stroke patients and 45 controls. MiR-221 was evaluated by quantitative real-time polymerase chain reaction (q-PCR) and IL-6 by enzyme-linked immunosorbent assay (ELISA). Our study results revealed that the serum miR-221 level was significantly reduced in cerebral ischemic stroke patients when compared to the control group (p<0.0001). In addition, serum miR-221 showed a significant negative correlation with cerebral stroke severity (p<0.0001), whereas serum IL-6 showed a significant positive correlation with cerebral stroke severity (p < 0.0001). We also analyzed the receiver operator characteristic (ROC) curve and found that area under the ROC curve (AUC) for severity of ischemic stroke by miR-221 was 0.97 (95% confidence intervall0.93-1, p<0.001). Notably, the combination of serum miR-221 with IL-6 for prediction of ischemic stroke severity showed both increased sensitivity/specificity (AUC=0.99, 95% confidence interval 0.96-1, p<0.001) than miR-221 alone. We concluded that miR-221 constituted a non-invasive, sensitive, and specific biomarker that could be used for diagnosis of ischemic stroke and for prediction of its severity., (Copyright© by the Egyptian Association of Immunologists.)

Background: Alterations of heart rate variability (HRV) in epileptic patients were the field of interest of several studies for many reasons, particularly the contribution toward sudden unexpected death in epilepsy (SUDEP)., Aim: We aimed at evaluation of autonomic dysfunction in epileptic patients during awake and sleep in addition to studying the association between SUDEP risk with different Holter parameters., Patients and Methods: The study included eighty epileptic patients (40 controlled epileptic patients and 40 refractory epileptic patients) compared to 30 volunteers as control group. They underwent detailed epileptic history, Chalfont seizure severity scale, sudden unexpected death in epilepsy (SUDEP)-7 risk score and 24 hour Holter monitoring to assess HRV parameters., Results: Patients with refractory epilepsy had longer duration of epilepsy with increased number of used AEDs compared to controlled epileptic group. Both controlled and refractory epileptic patients had significantly higher average heart rate (AV.HR), sympatho-vagal ratio (low-frequency/high-frequency (LF/HF) ratio in 24 hours, daytime, and nighttime), and LF and HF values compared to controls. The rMSSD (the root mean square of difference between successive normal intervals), Tri.Index (triangular index), and pNN50 (percentage of the number of pairs of consecutive beat-to-beat intervals that varied by 50 ms) were significantly reduced in both epileptic groups compared to controls. Among refractory epileptic patients, patients with generalized epilepsy had significantly higher severity epileptic scale, average heart rate, minimum heart rate, and LF/HF night, in addition to lower rMSSD and pNN50 compared to patients with focal epilepsy. We found positive correlation between the following Holter indices (LF/HF 24, LF/HF day, and LF/HF night) and the duration of the epilepsy, while negative correlations between Tri.Index, LF, and HF and the epileptic duration were detected. SUDEP-7 risk was negatively correlated with pNN50 and rMSSD; meanwhile, it was positively correlated with LF/HF 24. The severity of epilepsy among refractory epileptic patients was positively correlated with average heart rate but negatively correlated with pNN50 and rMSSD. Using linear regression analysis, we found that pNN50 and rMSSD could predict SUDEP-7 risk and severity of epilepsy in refractory epileptic patients., Conclusion: Epileptic patients (particularly refractory patients with generalized EEG findings and long duration) had reduced heart rate variability and hence impairment of parasympathetic activity with increased susceptibility for adverse outcomes. Moreover, pNN50 and rMSSD could be used as predictors for SUDEP-7 risk as well as severity of epilepsy in refractory epileptic patients., Competing Interests: There are no conflicts of interest related to this publication that the authors are aware of., (© 2022 Hamdy et al.)