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Multiplexed cellular imaging typically relies on the sequential application of detection probes, as antibodies or DNA barcodes, which is complex and time-consuming. To address this, we developed here protein nanobarcodes, composed of combinations of epitopes recognized by specific sets of nanobodies. The nanobarcodes are read in a single imaging step, relying on nanobodies conjugated to distinct fluorophores, which enables a precise analysis of large numbers of protein combinations. Fluorescence images from nanobarcodes were used as input images for a deep neural network, which was able to identify proteins with high precision. We thus present an efficient and straightforward protein identification method, which is applicable to relatively complex biological assays. We demonstrate this by a multicell competition assay, in which we successfully used our nanobarcoded proteins together with neurexin and neuroligin isoforms, thereby testing the preferred binding combinations of multiple isoforms, in parallel., Competing Interests: S.O.R. and F.O. are shareholders of NanoTag Biotechnologies GmbH. All other authors declare no potential conflict of interest., (Copyright: © 2023 de Jong-Bolm et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Competing Interests: The author has declared that no competing interests exist.

Competing Interests: The author has declared that no competing interests exist.

Competing Interests: The author has declared that no competing interests exist.

Competing Interests: The author has declared that no competing interests exist.

Competing Interests: The author has declared that no competing interests exist.

Competing Interests: The author has declared that no competing interests exist.

Background: Hip fracture is associated with increased mortality. Our aim was to study potential risk factors, including osteoporosis, associated with short- and long-term mortality in a prospectively recruited cohort of fragility hip fracture patients., Methodology/principal Findings: Fragility hip fracture patients aged >50 years admitted to a county hospital in Southern Norway in 2004 and 2005 were consecutively identified and invited for assessment. Patients with high energy or pathological fractures, patients with confusion, serious infections or who were non-residents in the catchment area were excluded. As part of a clinical routine, data were collected using questionnaires. Standardized bone density measurements of lumbar spine and hip were performed. Potential predictors of hip fracture mortality were tested using univariate and multivariate logistic regression analysis. A total of 432 hip fracture patients (129 males and 303 females) were prospectively identified. Among them 296 (85 males and 211 females) patients [mean age 80.7 (SD 9.1)] were assessed at the Osteoporosis center. Variables independently associated with short-term mortality (after 1 year) were in females older age [Odds Ratio (OR) 6.95] and in males older age (OR 5.74) and pulmonary disease (OR 3.20), whereas no associations were observed with mortality for 3 months after the fragility hip fracture. Variables independently associated with 5 years mortality in males was osteoporosis (OR 3.91) and older age (OR 6.95), and in females was dementia (OR 4.16) and older age (OR 2.80)., Conclusion: Apart from known predictors as age and comorbidity osteoporosis in our study was identified as a potential independent predictor of long-term hip fracture mortality in males. This is of particular importance as treatment with bisphosphonates after hip fracture has been shown to reduce hip fracture mortality and may be a clinical target to reduce the burden of the disease. Further studies however are needed to confirm the validity of this finding.

Objective: Reduced bone mineral density (BMD), assessed by Dual Energy X-ray absorptiometry (DXA), is a well-known risk factor for fragility fracture. A large proportion of patients with fracture have only slightly reduced BMD. Assessment of other bone structure features than BMD may improve identification of individuals at increased fracture risk. Digital X-ray radiogrammetry (DXR), which is a feasible tool for measurement of metacarpal cortical bone density, also gives an estimate of cortical bone porosity. Our primary aim was to explore the association between cortical porosity in the hand assessed by DXR and distal radius fracture., Methods: This case-control study included 123 women >50 years with distal radius fracture, and 170 controls. DXR was used to measure metacarpal BMD (DXR-BMD), cortical porosity (DXR-porosity), thickness (DXR-CT) and bone width (DXR-W) of the hand. Femoral neck BMD was measured by DXA., Results: The fracture group had a statistically significant lower DXR-BMD (0.492 vs. 0.524 g/cm(2) p<0.001), higher cortical DXR-porosity (0.01256 vs. 0.01093, p<0.001), less DXR-CT (0.148 vs. 0.161 cm, p<0.001) and lower femoral neck DXA-BMD (0.789 vs. 0.844 g/cm(2), p = 0.001) than the controls. In logistic regression analysis adjusted for age, a significant association with distal radius fracture (OR, 95% CI) was found for body mass index (0.930, 0.880-0.983), DXA-BMD (0.996, 0.995-0.999), DXR-BMD (0.990, 0.985-0.998), DXR-porosity (1.468, 1.278-1.687) and DXR-CT (0.997, 0.996-0.999). In an adjusted model, DXR-porosity remained the only variable associated with distal radius fracture (1.415, 1.194-1.677)., Conclusion: DXR derived porosity is associated with fracture at distal radius and might be a sensitive marker for skeletal fragility.

Competing Interests: The author has declared that no competing interests exist.

Competing Interests: The author has declared that no competing interests exist.

Background: Progression of age-related macular degeneration has been linked to iron dysregulation and oxidative stress that induce apoptosis of neural retinal cells. Since both antioxidants and chelating agents have been reported to reduce the progression of retinal lesions associated with AMD in experimental animals, the present study evaluates the ability of multi-functional antioxidants containing functional groups that can independently chelate redox metals and quench free radicals to protect the retina against light-induced retinal degeneration, a rat model of dry atrophic AMD., Methods/results: Proof of concept studies were conducted to evaluate the ability of 4-(5-hydroxypyrimidin-2-yl)-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 4) and 4-(5-hydroxy-4,6-dimethoxypyrimidin-2-yl)-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 8) to reduce retinal damage in 2-week dark adapted Wistar rats exposed to 1000 lx of light for 3 hours. Assessment of the oxidative stress markers 4- hydroxynonenal and nitrotyrosine modified proteins and Thioredoxin by ELISA and Western blots indicated that these compounds reduced the oxidative insult caused by light exposure. The beneficial antioxidant effects of these compounds in providing significant functional and structural protection were confirmed by electroretinography and quantitative histology of the retina., Conclusions/significance: The present study suggests that multi-functional compounds may be effective candidates for preventive therapy of AMD.

Competing Interests: The author has declared that no competing interests exist.

Competing Interests: The author has declared that no competing interests exist.

Competing Interests: The author has declared that no competing interests exist.

Competing Interests: The author has declared that no competing interests exist.