Redox hydrogels constitute the only electron-conducting phase in which water-soluble chemicals and biochemicals dissolve and diffuse. The combination of solubility and diffusion makes the ...electron-conducting gels permeable to water-soluble biochemicals and chemicals. The electron-conducting redox hydrogels serve to electrically connect the redox centers of enzymes to electrodes, enabling their use whenever leaching of electron-shuttling diffusional redox mediators must be avoided, which is the case in subcutaneously implanted biosensors for diabetes management and in miniature, potentially implantable, glucose-O
2 biofuel cells. Because the hydrogels envelope the redox enzymes, they electrically wire the reaction centers to electrodes irrespective of spatial orientation and connect to electrode redox centers of multiple enzyme layers. Hence, the attained current densities of enzyme substrate electrooxidation or electroreduction are much higher than with enzyme monolayers packed onto electrode surfaces.
Over the past two decades, measurements of carbon nanotube toxicity and biodistribution have yielded a wide range of results. Properties such as nanotube type (single-walled vs. multi-walled), ...purity, length, aggregation state, and functionalization, as well as route of administration, greatly affect both the biocompatibility and biodistribution of carbon nanotubes. These differences suggest that generalizable conclusions may be elusive and that studies must be material- and application-specific. Here, we assess the short- and long-term biodistribution and biocompatibility of a single-chirality DNA-encapsulated single-walled carbon nanotube complex upon intravenous administration that was previously shown to function as an in-vivo reporter of endolysosomal lipid accumulation. Regarding biodistribution and fate, we found bulk specificity to the liver and >90% signal attenuation by 14 days in mice. Using near-infrared hyperspectral microscopy to measure single nanotubes, we found low-level, long-term persistence in organs such as the heart, liver, lung, kidney, and spleen. Measurements of histology, animal weight, complete blood count; biomarkers of organ function all suggest short- and long-term biocompatibility. This work suggests that carbon nanotubes can be used as preclinical research tools in-vivo without affecting acute or long-term health.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Emerging evidence suggests that epigenetic regulation is dependent on metabolic state, and implicates specific metabolic factors in neural functions that drive behaviour
. In neurons, acetylation of ...histones relies on the metabolite acetyl-CoA, which is produced from acetate by chromatin-bound acetyl-CoA synthetase 2 (ACSS2)
. Notably, the breakdown of alcohol in the liver leads to a rapid increase in levels of blood acetate
, and alcohol is therefore a major source of acetate in the body. Histone acetylation in neurons may thus be under the influence of acetate that is derived from alcohol
, with potential effects on alcohol-induced gene expression in the brain, and on behaviour
. Here, using in vivo stable-isotope labelling in mice, we show that the metabolism of alcohol contributes to rapid acetylation of histones in the brain, and that this occurs in part through the direct deposition of acetyl groups that are derived from alcohol onto histones in an ACSS2-dependent manner. A similar direct deposition was observed when mice were injected with heavy-labelled acetate in vivo. In a pregnant mouse, exposure to labelled alcohol resulted in the incorporation of labelled acetyl groups into gestating fetal brains. In isolated primary hippocampal neurons ex vivo, extracellular acetate induced transcriptional programs related to learning and memory, which were sensitive to ACSS2 inhibition. We show that alcohol-related associative learning requires ACSS2 in vivo. These findings suggest that there is a direct link between alcohol metabolism and gene regulation, through the ACSS2-dependent acetylation of histones in the brain.
Emery‐Dreifuss muscular dystrophy (EDMD) is a rare muscular dystrophy, but is particularly important to diagnose due to frequent life‐threatening cardiac complications. EDMD classically presents with ...muscle weakness, early contractures, cardiac conduction abnormalities and cardiomyopathy, although the presence and severity of these manifestations vary by subtype and individual. Associated genes include EMD, LMNA, SYNE1, SYNE2, FHL1, TMEM43, SUN1, SUN2, and TTN, encoding emerin, lamin A/C, nesprin‐1, nesprin‐2, FHL1, LUMA, SUN1, SUN2, and titin, respectively. The Online Mendelian Inheritance in Man database recognizes subtypes 1 through 7, which captures most but not all of the associated genes. Genetic diagnosis is essential whenever available, but traditional diagnostic tools can help steer the evaluation toward EDMD and assist with interpretation of equivocal genetic test results. Management is primarily supportive, but it is important to monitor patients closely, especially for potential cardiac complications. There is a high potential for progress in the treatment of EDMD in the coming years.
This study quantifies the wide-ranging health care costs affecting patients living with IBD, including the annualized direct and indirect costs of care for patients with IBD, the longitudinal drivers ...of these costs, and the cost of care for newly diagnosed patients.
Abstract
Background
The Crohn’s & Colitis Foundation’s Cost of Inflammatory Bowel Disease (IBD) Care Initiative seeks to quantify the wide-ranging health care costs affecting patients living with IBD. We aimed to (1) describe the annualized direct and indirect costs of care for patients with Crohn’s disease (CD) or ulcerative colitis (UC), (2) determine the longitudinal drivers of these costs, and (3) characterize the cost of care for newly diagnosed patients.
Methods
We analyzed the Optum Research Database from the years 2007 to 2016, representing commercially insured and Medicare Advantage–insured patients in the United States. Inclusion for the study was limited to those who had continuous enrollment with medical and pharmacy benefit coverage for at least 24 months (12 months before through 12 months after the index date of diagnosis). The value of patient time spent on health care was calculated as number of workplace hours lost due to health care encounters multiplied by the patients’ estimated average wage derived from the Bureau of Labor Statistics. Comparisons between IBD patients and non-IBD patients were analyzed based on demographics, health plan type, and length of follow-up. We used generalized linear models to estimate the association between total annual costs and various patient variables.
Results
There were 52,782 IBD patients (29,062 UC; 23,720 CD) included in the analysis (54.1% females). On a per-annual basis, patients with IBD incurred a greater than 3-fold higher direct cost of care compared with non-IBD controls ($22,987 vs $6956 per-member per-year paid claims) and more than twice the out-of-pocket costs ($2213 vs $979 per-year reported costs), with all-cause IBD costs rising after 2013. Patients with IBD also experienced significantly higher costs associated with time spent on health care as compared with controls. The burden of costs was most notable in the first year after initial IBD diagnosis (mean = $26,555). The study identified several key drivers of cost for IBD patients: treatment with specific therapeutics (biologics, opioids, or steroids); ED use; and health care services associated with relapsing disease, anemia, or mental health comorbidity.
Conclusion
The costs of care for IBD have increased in the last 5 years and are driven by specific therapeutics and disease features. In addition, compared with non-IBD controls, IBD patients are increasingly incurring higher costs associated with health care utilization, out-of-pocket expenditures, and workplace productivity losses. There is a pressing need for cost-effective strategies to address these burdens on patients and families affected by IBD.
Video Abstract
10.1093/ibd/izz104_video1
Video Abstract
izz104.video1
6039344358001
The cellular uptake and expulsion rates of length-fractionated single-walled carbon nanotubes (SWNT) from 130 to 660 nm in NIH-3T3 cells were measured via single particle tracking of their intrinsic ...photoluminescence. We develop a quantitative model to correlate endocytosis rate with nanoparticle geometry that accurately describes this data set and also literature results for Au nanoparticles. The model asserts that nanoparticles cluster on the cell membrane to form a size sufficient to generate a large enough enthalpic contribution via receptor ligand interactions to overcome the elastic energy and entropic barriers associated with vesicle formation. Interestingly, the endocytosis rate constant of SWNT (10−3 min−1) is found to be nearly 1000 times that of Au nanoparticles (10−6 min−1) but the recycling (exocytosis) rate constants are similar in magnitude (10−4 to 10−3 min−1) for poly(d,l-lactide-co-glycolide), SWNT, and Au nanoparticles across distinct cell lines. The total uptake of both SWNT and Au nanoparticles is maximal at a common radius of 25 nm when scaled using an effective capture dimension for membrane diffusion. The ability to understand and predict the cellular uptake of nanoparticles quantitatively should find utility in designing nanosystems with controlled toxicity, efficacy, and functionality.
Antibiotic susceptibility testing is often performed to determine the most effective antibiotic treatment for a bacterial infection, or perhaps to determine if a particular strain of bacteria is ...becoming drug resistant. Such tests, and others used to determine efficacy of candidate antibiotics during the drug discovery process, have resulted in a demand for more rapid susceptibility testing methods. Here, we have developed a susceptibility test that utilizes chemiluminescent determination of ATP release from bacteria and the overall optical density (OD600) of the bacterial solution. Bacteria release ATP during a growth phase or when they are lysed in the presence of an effective antibiotic. Because optical density increases during growth phase, but does not change during bacterial lysing, an increase in the ATP:optical density ratio after the bacteria have reached the log phase of growth (which is steady) would indicate antibiotic efficacy. Specifically, after allowing a kanamycin-resistant strain of Escherichia coli (E.coli) to pass through the growth phase and reach steady state, the addition of levofloxacin, an antibiotic to which E. coli is susceptible, resulted in a significant increase in the ATP:OD600 ratio in comparison to the use of kanamycin alone (1.80 +/- 0.50 vs. 1.12 +/- 0.28). This difference could be measured 20 minutes after the addition of the antibiotic, to which the bacteria are susceptible, to the bacterial sample. Furthermore, this method also proved useful with gram positive bacteria, as the addition of kanamycin to a chloramphenicol-resistant strain of Bacillus subtilis (B. subtilis) resulted in an ATP:OD600 ratio of 2.14 +/- 0.26 in comparison to 0.62 +/- 0.05 for bacteria not subjected to the antibiotic to which the bacteria are susceptible. Collectively, these results suggest that measurement of the ATP:OD600 ratio may provide a susceptibility test for antibiotic efficacy that is more rapid and quantitative than currently accepted techniques.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
For many biological applications, exploration of the massive parametric space of a mechanism-based model can impose a prohibitive computational demand. To overcome this limitation, we present a ...framework to improve computational efficiency by orders of magnitude. The key concept is to train a neural network using a limited number of simulations generated by a mechanistic model. This number is small enough such that the simulations can be completed in a short time frame but large enough to enable reliable training. The trained neural network can then be used to explore a much larger parametric space. We demonstrate this notion by training neural networks to predict pattern formation and stochastic gene expression. We further demonstrate that using an ensemble of neural networks enables the self-contained evaluation of the quality of each prediction. Our work can be a platform for fast parametric space screening of biological models with user defined objectives.
Single‐walled carbon nanotubes form the basis of new non‐photobleaching cell markers that remain visible in live cells for up to three months and do not impede cell viability. In‐vitro spectroscopy ...of the intrinsic near‐IR fluorescence and Raman scattering of the nanotubes maps the localization of nanotube complexes, which accumulate in perinuclear endosomes (see Figure). The markers are also detectable in hematoxylin and eosin stained cells and exhibit spectral changes due to the nanotubes' environment.
Medulloblastoma is the most common malignant paediatric brain tumour, with ~30% mediated by Sonic hedgehog signalling. Vismodegib-mediated inhibition of the Sonic hedgehog effector Smoothened ...inhibits tumour growth but causes growth plate fusion at effective doses. Here, we report a nanotherapeutic approach targeting endothelial tumour vasculature to enhance blood-brain barrier crossing. We use fucoidan-based nanocarriers targeting endothelial P-selectin to induce caveolin-1-dependent transcytosis and thus nanocarrier transport into the brain tumour microenvironment in a selective and active manner, the efficiency of which is increased by radiation treatment. In a Sonic hedgehog medulloblastoma animal model, fucoidan-based nanoparticles encapsulating vismodegib exhibit a striking efficacy and marked reduced bone toxicity and drug exposure to healthy brain tissue. Overall, these findings demonstrate a potent strategy for targeted intracranial pharmacodelivery that overcomes the restrictive blood-brain barrier to achieve enhanced tumour-selective penetration and has therapeutic implications for diseases within the central nervous system.
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