Drug repurposing is used to propose new therapeutic perspectives. Here, we introduce “Drug Upgrade”, that is, characterizing the mode of action of an old drug to generate new chemical entities and ...new therapeutics. We proposed a novel methodology covering target identification to pharmacology validation. As an old drug, we chose hydroxychloroquine (HCQ) for its well‐documented clinical efficacy in lupus and its side effect, retinal toxicity. Using the Nematic Protein Organization Technique (NPOT®) followed by liquid chromatography‐tandem mass spectrometry analyses, we identified myeloperoxidase (MPO) and alpha‐crystallin β chain (CRYAB) as primary and secondary targets to HCQ from lupus patients' peripheral blood mononuclear cells (PBMCs) and isolated human retinas. Surface plasmon resonance (SPR) and enzymatic assays confirmed the interaction of HCQ with MPO and CRYAB. We synthesized INS‐072 a novel analog of HCQ that increased affinity for MPO and decreased binding to CRYAB compared to HCQ. INS‐072 delayed cutaneous eruption significantly compared to HCQ in the murine MRL/lpr model of spontaneous lupus and prevents immune complex vasculitis in mice. In addition, long‐term HCQ treatment caused retinal toxicity in mice, unlike INS‐072. Our study illustrates a method of drug development, where new applications or improvements can be explored by fully characterizing the drug's mode of action.
The complex mechanics of the gastric wall facilitates the main digestive tasks of the stomach. However, the interplay between the mechanical properties of the stomach, its microstructure, and its ...vital functions is not yet fully understood. Importantly, the pig animal model is widely used in biomedical research for preliminary or ethically prohibited studies of the human digestion system. Therefore, this study aims to thoroughly characterize the mechanical behavior and microstructure of the porcine stomach. For this purpose, multiple quasi-static mechanical tests were carried out with three different loading modes, i.e., planar biaxial extension, radial compression, and simple shear. Stress-relaxation tests complemented the quasi-static experiments to evaluate the deformation and strain-dependent viscoelastic properties. Each experiment was conducted on specimens of the complete stomach wall and two separate layers, mucosa and muscularis, from each of the three gastric regions, i.e., fundus, body, and antrum. The significant preconditioning effects and the considerable regional and layer-specific differences in the tissue response were analyzed. Furthermore, the mechanical experiments were complemented with histology to examine the influence of the microstructural composition on the macrostructural mechanical response and vice versa. Importantly, the shear tests showed lower stresses in the complete wall compared to the single layers which the loose network of submucosal collagen might explain. Also, the stratum arrangement of the muscularis might explain mechanical anisotropy during tensile tests. This study shows that gastric tissue is characterized by a highly heterogeneous microstructure with regional variations in layer composition reflecting not only functional differences but also diverse mechanical behavior. STATEMENT OF SIGNIFICANCE: Unfortunately, only few experimental data on gastric tissue are available for an adequate material parameter and model estimation. The present study therefore combines layer- and region-specific stomach wall mechanics obtained under multiple loading conditions with histological insights into the heterogeneous microstructure. On the one hand, the extensive data sets of this study expand our understanding of the interplay between gastric mechanics, motility and functionality, which could help to identify and treat associated pathologies. On the other hand, such data sets are of high relevance for the constitutive modeling of stomach tissue, and its application in the field of medical engineering, e.g., in the development of surgical staplers and the improvement of bariatric surgical interventions.
Objectives
The recently proposed standardized reporting and data system for somatostatin receptor (SSTR)–targeted PET/CT SSTR-RADS 1.0 showed promising first results in the assessment of diagnosis ...and treatment planning with peptide receptor radionuclide therapy (PRRT) in neuroendocrine tumors (NET). This study aimed to determine the intra- and interreader agreement of SSTR-RADS 1.0.
Methods
SSTR-PET/CT scans of 100 patients were independently evaluated by 4 readers with different levels of expertise according to the SSTR-RADS 1.0 criteria at 2 time points within 6 weeks. For each scan, a maximum of five target lesions were freely chosen by each reader (not more than three lesions per organ) and stratified according to the SSTR-RADS 1.0 criteria. Overall scan score and binary decision on PRRT were assessed. Intra- and interreader agreement was determined using the intraclass correlation coefficient (ICC).
Results
Interreader agreement using SSTR-RADS 1.0 for identical target lesions (ICC ≥ 0.91) and overall scan score (ICC ≥ 0.93) was excellent. The decision to state “functional imaging fulfills requirements for PRRT and qualifies patient as potential candidate for PRRT” also demonstrated excellent agreement among all readers (ICC ≥ 0.86). Intrareader agreement was excellent even among different experience levels when comparing target lesion–based scores (ICC ≥ 0.98), overall scan score (ICC ≥ 0.93), and decision for PRRT (ICC ≥ 0.88).
Conclusion
SSTR-RADS 1.0 represents a highly reproducible and accurate system for stratifying SSTR-targeted PET/CT scans with high intra- and interreader agreement. The system is a promising approach to standardize the diagnosis and treatment planning in NET patients.
Key Points
• SSTR-RADS 1.0 offers high reproducibility and accuracy.
• SSTR-RADS 1.0 is a promising method to standardize diagnosis and treatment planning for patients with NET.
Amyotrophic lateral sclerosis (ALS) is a devastating, adult-onset neurodegenerative disorder of the upper and lower motor systems. It leads to paresis, muscle wasting and inevitably to death, ...typically within 3-5 years. However, disease onset and survival vary considerably ranging in extreme cases from a few months to several decades. The genetic and environmental factors underlying this variability are of great interest as potential therapeutic targets. In ALS, men are affected more often and have an earlier age of onset than women. This gender difference is recapitulated in transgenic rodent models, but no underlying mechanism has been elucidated. Here we report that SNPs in the brain-specific promoter region of the transcriptional co-activator PGC-1α, a master regulator of metabolism, modulate age of onset and survival in two large and independent ALS populations and this occurs in a strictly male-specific manner. In complementary animal studies, we show that deficiency of full-length (FL) Pgc-1α leads to a significantly earlier age of onset and a borderline shortened survival in male, but not in female ALS-transgenic mice. In the animal model, FL Pgc-1α-loss is associated with reduced mRNA levels of the trophic factor Vegf-A in males, but not in females. In summary, we indentify PGC-1α as a novel and clinically relevant disease modifier of human and experimental ALS and report a sex-dependent effect of PGC-1α in this neurodegenerative disorder.
Abstract In response to the evolving treatment landscape for new‐onset refractory status epilepticus (NORSE) and the publication of consensus recommendations in 2022, we conducted a comparative ...analysis of NORSE management over time. Seventy‐seven patients were enrolled by 32 centers, from July 2016 to August 2023, in the NORSE/FIRES biorepository at Yale. Immunotherapy was administered to 88% of patients after a median of 3 days, with 52% receiving second‐line immunotherapy after a median of 12 days (anakinra 29%, rituximab 25%, and tocilizumab 19%). There was an increase in the use of second‐line immunotherapies (odds ratio OR = 1.4, 95% CI = 1.1–1.8) and ketogenic diet (OR = 1.8, 95% CI = 1.3–2.6) over time. Specifically, patients from 2022 to 2023 more frequently received second‐line immunotherapy (69% vs 40%; OR = 3.3; 95% CI = 1.3–8.9)—particularly anakinra (50% vs 13%; OR = 6.5; 95% CI = 2.3–21.0), and the ketogenic diet (OR = 6.8; 95% CI = 2.5–20.1)—than those before 2022. Among the 27 patients who received anakinra and/or tocilizumab, earlier administration after status epilepticus onset correlated with a shorter duration of status epilepticus ( ρ = .519, p = .005). Our findings indicate an evolution in NORSE management, emphasizing the increasing use of second‐line immunotherapies and the ketogenic diet. Future research will clarify the impact of these treatments and their timing on patient outcomes.
Febrile infection‐related epilepsy syndrome (FIRES) is a subset of new onset refractory status epilepticus (NORSE) that involves a febrile infection prior to the onset of the refractory status ...epilepticus. It is unclear whether FIRES and non‐FIRES NORSE are distinct conditions. Here, we compare 34 patients with FIRES to 30 patients with non‐FIRES NORSE for demographics, clinical features, neuroimaging, and outcomes. Because patients with FIRES were younger than patients with non‐FIRES NORSE (median = 28 vs. 48 years old, p = .048) and more likely cryptogenic (odds ratio = 6.89), we next ran a regression analysis using age or etiology as a covariate. Respiratory and gastrointestinal prodromes occurred more frequently in FIRES patients, but no difference was found for non‐infection‐related prodromes. Status epilepticus subtype, cerebrospinal fluid (CSF) and magnetic resonance imaging findings, and outcomes were similar. However, FIRES cases were more frequently cryptogenic; had higher CSF interleukin 6, CSF macrophage inflammatory protein‐1 alpha (MIP‐1a), and serum chemokine ligand 2 (CCL2) levels; and received more antiseizure medications and immunotherapy. After controlling for age or etiology, no differences were observed in presenting symptoms and signs or inflammatory biomarkers, suggesting that FIRES and non‐FIRES NORSE are very similar conditions.
Background The purpose of the study was to investigate a novel BRAF and CDK 4/6 inhibitor combination therapy in a murine model of BRAF-V600-mutant human melanoma monitored by .sup.18F-FDG-PET/CT and ...diffusion-weighted MRI (DW-MRI). Methods Human BRAF-V600-mutant melanoma (A375) xenograft-bearing balb/c nude mice (n = 21) were imaged by .sup.18F-FDG-PET/CT and DW-MRI before (day 0) and after (day 7) a 1-week BRAF and CDK 4/6 inhibitor combination therapy (n = 12; dabrafenib, 20 mg/kg/d; ribociclib, 100 mg/kg/d) or placebo (n = 9). Animals were scanned on a small animal PET after intravenous administration of 20 MBq .sup.18F-FDG. Tumor glucose uptake was calculated as the tumor-to-liver-ratio (TTL). Unenhanced CT data sets were subsequently acquired for anatomic coregistration. Tumor diffusivity was assessed by DW-MRI using the apparent diffusion coefficient (ADC). Anti-tumor therapy effects were assessed by ex vivo immunohistochemistry for validation purposes (microvascular density - CD31; tumor cell proliferation - Ki-67). Results Tumor glucose uptake was significantly suppressed under therapy (DELATTL.sub.Therapy - 1.00 + or - 0.53 vs. DELATTL.sub.Control 0.85 + or - 1.21; p 0.001). In addition, tumor diffusivity was significantly elevated following the BRAF and CDK 4/6 inhibitor combination therapy (DELAADC.sub.Therapy 0.12 + or - 0.14 x 10.sup.-3 mm.sup.2/s; DELAADC.sub.Control - 0.12 + or - 0.06 x 10.sup.-3 mm.sup.2/s; p 0.001). Immunohistochemistry revealed a significant suppression of microvascular density (CD31, 147 + or - 48 vs. 287 + or - 92; p = 0.001) and proliferation (Ki-67, 3718 + or - 998 vs. 5389 + or - 1332; p = 0.007) in the therapy compared to the control group. Conclusion A novel BRAF and CDK 4/6 inhibitor combination therapy exhibited significant anti-angiogenic and anti-proliferative effects in experimental human melanomas, monitored by .sup.18F-FDG-PET/CT and DW-MRI. Keywords: Melanoma, BRAF inhibitor, CDK inhibitor, .sup.18F-FDG-PET, Diffusion-weighted MRI, Therapy monitoring
The molecular motor dynein and its associated regulatory subunit dynactin have been implicated in several neurodegenerative conditions of the basal ganglia, such as Huntington's disease (HD) and ...Perry syndrome, an atypical Parkinson-like disease. This pathogenic role has been largely postulated from the existence of mutations in the dynactin subunit p150Glued. However, dynactin is also able to act independently of dynein, and there is currently no direct evidence linking dynein to basal ganglia degeneration. To provide such evidence, we used here a mouse strain carrying a point mutation in the dynein heavy chain gene that impairs retrograde axonal transport. These mice exhibited motor and behavioural abnormalities including hindlimb clasping, early muscle weakness, incoordination and hyperactivity. In vivo brain imaging using magnetic resonance imaging showed striatal atrophy and lateral ventricle enlargement. In the striatum, altered dopamine signalling, decreased dopamine D1 and D2 receptor binding in positron emission tomography SCAN and prominent astrocytosis were observed, although there was no neuronal loss either in the striatum or substantia nigra. In vitro, dynein mutant striatal neurons displayed strongly impaired neuritic morphology. Altogether, these findings provide a direct genetic evidence for the requirement of dynein for the morphology and function of striatal neurons. Our study supports a role for dynein dysfunction in the pathogenesis of neurodegenerative disorders of the basal ganglia, such as Perry syndrome and HD.
Abstract
In the thin film limit, the surface state of a three-dimensional topological insulator gives rise to two parallel conduction channels at the top and bottom surface of the film, which are ...difficult to disentangle in transport experiments. Here, we present gate-dependent multi-tip scanning tunneling microscope transport measurements combined with photoemission experiments all performed in situ on pristine BiSbTe
3
thin films. To analyze the data, we develop a generic transport model including quantum capacitance effects. This approach allows us to quantify the gate-dependent conductivities, charge carrier concentrations, and mobilities for all relevant transport channels of three-dimensional topological insulator thin films (i.e., the two topological surface state channels, as well as the interior of the film). For the present sample, we find that the conductivity in the bottom surface state channel is minimized below a gate voltage of
V
gate
= −34 V and the top surface state channel dominates the transport through the film.
ABSTRACT
Mapping brain function to brain structure is a fundamental task for neuroscience. For such an endeavour, the Drosophila larva is simple enough to be tractable, yet complex enough to be ...interesting. It features about 10,000 neurons and is capable of various taxes, kineses and Pavlovian conditioning. All its neurons are currently being mapped into a light-microscopical atlas, and Gal4 strains are being generated to experimentally access neurons one at a time. In addition, an electron microscopic reconstruction of its nervous system seems within reach. Notably, this electron microscope-based connectome is being drafted for a stage 1 larva – because stage 1 larvae are much smaller than stage 3 larvae. However, most behaviour analyses have been performed for stage 3 larvae because their larger size makes them easier to handle and observe. It is therefore warranted to either redo the electron microscopic reconstruction for a stage 3 larva or to survey the behavioural faculties of stage 1 larvae. We provide the latter. In a community-based approach we called the Ol1mpiad, we probed stage 1 Drosophila larvae for free locomotion, feeding, responsiveness to substrate vibration, gentle and nociceptive touch, burrowing, olfactory preference and thermotaxis, light avoidance, gustatory choice of various tastants plus odour–taste associative learning, as well as light/dark–electric shock associative learning. Quantitatively, stage 1 larvae show lower scores in most tasks, arguably because of their smaller size and lower speed. Qualitatively, however, stage 1 larvae perform strikingly similar to stage 3 larvae in almost all cases. These results bolster confidence in mapping brain structure and behaviour across developmental stages.
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