Sensitive monitoring of NAD(P)H levels within cancer cells using mitochondria-targeted near-infrared cyanine dyes with optimized electron-withdrawing acceptors.

A series of near-infrared fluorescent probes, labeled A to E, were developed by combining electron-rich thiophene and 3,4-ethylenedioxythiophene bridges with 3-quinolinium and various electron deficient groups, enabling the sensing of NAD(P)H. Probes A and B exhibit absorptions and emissions in the near-infrared range, offering advantages such as minimal interference from autofluorescence, negligible photo impairment in cells and tissues, and exceptional tissue penetration. These probes show negligible fluorescence when NADH is not present, and their absorption maxima are at 438 nm and 470 nm, respectively. In contrast, probes C-E feature absorption maxima at 450, 334 and 581 nm, respectively. Added NADH triggers the transformation of the electron-deficient 3-quinolinium units into electron-rich 1,4-dihydroquinoline units resulting in fluorescence responses which were established at 748, 730, 575, 625 and 661 for probes AH-EH, respectively, at detection limits of 0.15 µM and 0.07 µM for probes A and B, respectively. Optimized geometries based on theoretical calculations reveal non-planar geometries for probes A-E due to twisting of the 3-quinolinium and benzothiazolium units bonded to the central thiophene group, which all attain planarity upon addition of hydride resulting in absorption and fluorescence in the near-IR region for probes AH and BH in contrast to probes CH-EH which depict fluorescence in the visible range. Probe A has been successfully employed to monitor NAD(P)H levels in glycolysis and specific mitochondrial targeting. Furthermore, it has been used to assess the influence of lactate and pyruvate on the levels of NAD(P)H, to explore how hypoxia in cancer cells can elevate levels of NAD(P)H, and to visualize changes in levels of NAD(P)H under hypoxic conditions with CoCl2 treatment. Additionally, probe A has facilitated the examination of the potential impact of chemotherapy drugs, namely gemcitabine, camptothecin, and cisplatin, on metabolic processes and energy generation within cancer cells by affecting NAD(P)H levels. Treatment of A549 cancer cells with these drugs has been shown to increase NAD(P)H levels, which may contribute to their anticancer effects ultimately leading to programmed cell death or apoptosis. Moreover, probe A has been successfully employed in monitoring NAD(P)H level changes in D. melanogaster larvae treated with cisplatin.

Accuracy and reliability of bedside thoracic ultrasound in detecting pulmonary pathology in a heterogeneous pediatric intensive care unit population.

PURPOSE: This study was designed to access sensitivity and specificity of detection of lung abnormalities by the ultrasound (US) done by PICU providers of varying levels of experience compared to CXR and to assess the inter-rater reliability in the interpretation of the USG findings. METHODS: Up to three US examinations were performed on patients meeting eligibility criteria. US examinations were reported by the operator and remotely by an expert reader. Both operator and readers interpretation were correlated with CXR read by an independent pulmonologist. RESULTS: One hundred and thirty-five US examinations were performed on 91 patients over 9 months. Overall agreement between the operator and reader of the US was 0.53 (0.38-0.68). The agreement was highest with an expert-expert pair (0.75) and lowest with a novice-expert pair (0.27). Sensitivity and specificity of thoracic US to detect pulmonary abnormalities showed a high sensitivity by the operator (82.5%) compared to the reader (63.4%). Specificity was 25% and 42.8%, respectively. US was overall highly sensitive to detect pneumonia (96.4%) with a 100% PPV, but only modest for bronchiolitis. CONCLUSIONS: Lungs US is a rapid and sensitive bedside tool to assess lung consolidation in children in ICU. It, however, has low negative predictive values, and negative US examinations cannot rule out lung pathology.