CHO cells have been recently shown to produce amino acid catabolism derived byproducts, which accumulate in fed-batch cultures to growth-inhibitory levels. Residual amino acid limitation or genetic engineering strategies have been successfully employed to suppress production of these novel growth inhibitory metabolic byproducts. However, the growth advantage attained due to suppression of these metabolic byproducts in fed-batch cultures is more pronounced when lactate accumulation is also controlled. BCAT1 knock-out (KO) CHO cells, which produce negligible levels of the metabolic byproducts isovalerate, isobutyrate and 2-methylbutyrate, grow to significantly higher peak cell densities in fed-batch cultures with lactate control (HiPDOG) as compared to cultures without lactate control. Henceforth, strategies involving novel metabolic byproduct control should preferably include lactate control to more easily assess the enhanced cell growth and productivities attainable.
Research hypotheses have been a cornerstone of science since before Galileo. Many have argued that inclusion of multiple hypotheses (1) encourage discovery of mechanisms, and (2) reduce bias – both features that should increase transferability and reproducibility. However, we are entering a new era of big data and highly predictive models where some argue the hypothesis is outmoded. Indeed, using a detailed literature analysis, we found prevalence of hypotheses in eco-evo research is very low (6.7-26%) and static from 1990-2015, a pattern mirrored in an extensive literature search (N=302,558 articles). Our literature review also indicates that neither grant success or citation rates were related to the inclusion of hypotheses, which may provide disincentive for hypothesis formulation. Here we confront common justifications for avoiding hypotheses and present new arguments based on benefits to the individual. Although hypotheses are not always necessary, we expect their continued and increased use will help our fields move toward greater understanding, reproducibility, prediction, and effective conservation of nature.
Background: Selective IgA deficiency (SIgAD) is the most prevalent primary immunodeficiency with almost unknown etiology. This study aimed to investigate the clinical diagnostic and prognostic values of lymphocytes subsets and function in symptomatic SIgAD patients. Methods: A total of 30 available SIgAD patients from the Iranian registry and 30 age-sex-matched healthy controls were included in the present study. We analyzed B and T cell peripheral subsets and T cell proliferation assay by flow cytometry in SIgAD patients with mild and severe clinical phenotypes. Results: Our results indicated a significant increase in naïve and transitional B cells and a strong decrease in marginal zone-like and switched memory B-cells in SIgAD patients. We found that naïve and central memory CD4+ T cell subsets, as well as Th1, Th2 and regulatory T cells have significantly decreased. On the other hand, there was a significant reduction in central and effector memory CD8+ T cell subsets, whereas proportions of both (CD4+ and CD8+) terminally differentiated effector memory T cells (TEMRA) were significantly elevated in our patients. Although some of T cell subsets in severe SIgAD were similar, decrease in marginal-zone and switched memory B cells and increase in CD21low B cell of severe SIgAD patients were slightly prominent. Moreover, the proliferation activity of CD4+ T cells was strongly impaired in SIgAD patients with a severe phenotype. Conclusion: SIgAD patients have varied cellular and humoral deficiencies. Therefore, T cell and B cell assessment might help in better understanding the heterogeneous pathogenesis and prognosis estimation of the disease. Keywords: Primary immunodeficiency, Selective IgA deficiency, B cell subsets, T cell subsets, flow cytometry, proliferation assay
COVID-19 is a complex disease and many difficulties are faced today especially in the proper choice of pharmacological treatments. The role of antiviral agents for COVID-19 is still being investigated. The evidence for immunomodulatory and anti-inflammatory drugs is quite conflicting, while the use of corticosteroids is supported by robust evidence. The use of heparins in hospitalized critically ill patients is preferred over other anticoagulants. Lastly, conflicting data were found regarding to the use of convalescent plasma and vitamin D. According to data shared by the WHO, many vaccines are under phase 3 clinical trials and some of them already received the marketing approval in EU countries and in the US. In conclusion, drugs repurposing has represented the main approach recently used in the treatment of patients with COVID-19. At this moment, the analysis of efficacy and safety data of drugs and vaccines used in real life context is strongly needed.
Background The maturation of innate immune responses in health and atopy is still incompletely understood. Methods We aimed to evaluate age-related trajectories of the TLR3 and TLR7/8 pathways across the lifespan and whether these differ between healthy and atopic individuals. Peripheral blood mononuclear cells (PBMCs) were isolated from 39 otherwise healthy atopic and 39 non-atopic subjects, aged 0-45 years. Selected cytokines involved in antiviral responses were measured by Luminex in culture supernatants of poly(I:C)- and R848-stimulated PBMCs. The non-parametric correlation between age and cytokine expression and differences in developmental trajectories between healthy and atopic were estimated. Patterns of cytokine development were identified with principal component analysis. Results Normal innate immune maturation entails significant and progressive age-related changes in the production of IL-1β, TNF-α, MIP-1β, MCP-3, IP-10, IL-10, IL-12p70 and IFN-γ upon TLR3 and/or TLR7/8 stimulation. Individual cytokines made small contributions to the observed variability; chemokines MCP-3 and IP-10 were key contributors. The development of these pathways deviated in atopic subjects with significant differences observed in the trajectories of IL-1β, MIP-1β and IL-10 synthesis. Conclusion TLR3 and TLR7/8 pathways mature during childhood, while atopy is associated with an abnormal maturation pattern. Suboptimal responses in Th1, inflammatory cytokine and chemokine production may be implicated in poor antiviral immunity in atopics, while deficient maturation of IL-10 producing capacity in the breaking of tolerance.
T cell receptor excision circles (TRECs) are small circularized DNA elements produced during rearrangement of T cell receptor (TCR) genes. Because TRECS are fairly stable, do not replicate during mitosis, and are not diluted during division of naïve T cells1, they are suitable for assessing the number of newly formed T cells 2. In this study, we detected TRECs in 475 healthy Chinese children aged 0–18 years in different clinical settings. We found a strong correlation between TRECs levels and peripheral CD4 naïve T cell numbers, but not between TRECs levels and effector or memory CD4 and CD8 T cell numbers. TRECs levels fell significantly compared with normal controls in patients with severe combined immunodeficiencies (SCID) (n=7), wiskott-aldrich syndrome (WAS) (n=22), or activated PI3Kδ syndrome (APDS) (n=5). TRECs levels in those with signal transducer and activator of transcription 1 (STAT1) deficiency (n=8) decreased or did not change significantly, a finding consistent with that for CD4 naïve T cells. We also measured TRECs levels in seven PIDs after hematopoietic stem cell transplantation (HSCT) (WAS=5; chronic granulomatous disease (CGD)=2), and found the complications after HSCT may reduce TRECs levels by interfering with production of naïve T cells. In conclusion, we established reference values for TRECs, which can be used to screen for primary immunodeficiency diseases (PIDs) during early life and track immune reconstitution after HSCT.
Background: This study evaluates the impact of peak preoperative troponin level on outcomes of coronary artery bypass grafting (CABG) for non-ST-elevation myocardial infarction (NSTEMI). Methods: This was a retrospective review of patients undergoing isolated CABG from 2011-2018 with presentation of NSTEMI. Patients were stratified into low- and high-risk groups based on median preoperative peak troponin (1.95ng/dL). Major cardiac and cerebrovascular events (MACCE) and mortality were compared. Multivariable analysis was performed to model risk factors for MACCE and mortality. Results: This study included 1,211 patients, 607 low- (≤1.95ng/dL) and 604 high-risk (>1.95ng/dL). Patients were well-matched with respect to age and comorbidity. High-risk patients had lower median preoperative ejection fraction (46.5% [IQR 35.0%-55.0%] vs 53.0% [IQR 40.0%-58.0%]) and higher incidence of preoperative intra-aortic balloon pump (15.9% vs 8.73%). Intensive care unit (47 hours [IQR 26-82] vs 43 hours [IQR 25-69]) and hospital lengths of stay (10 days [IQR 8-13] vs 9 days [IQR 8-12]) were longer in the high-risk group (each P<0.05). Postoperative complications and thirty-day, one- and five-year rates of both MACCE and survival were similar between groups. Peak troponin >1.95ng/dL was not associated with increased hazards for MACCE, mortality, or readmission in multivariable modeling. In sub-analyses, neither increasing troponin as a continuous variable nor peak troponin >10.00ng/mL were associated with increased hazards for these outcomes. Conclusions: Higher preoperative troponin levels are associated with longer lengths of stay but not MACCE or mortality following CABG. Dictating timing of CABG for NSTEMI based on peak troponin does not appear to be warranted.
Cardiovascular disturbances are the leading causes of morbidity and mortality in patients of spinal cord particularly cervical cord injury accounting for approximately 30% of deaths. Most common cardiovascular dysfunctions are sinus bradycardia, hypotension, cardiac arrest, supraventricular tachycardia and all these occurs due to sympathetic withdrawal and unopposed vagal action. Here we are reporting a case of acute cervical cord injury with neurogenic shock in a 25 year young patient who developed polymorphic ventricular tachycardia, which degenerated to ventricular fibrillation and cardiac arrest. We described all possible mechanisms of development this arrythmia and its management.
In this paper, we consider the Cauchy problem for a family of evolution-parabolic coupled systems, which are related to the classical thermoelastic plate equations containing non-local operators. By using diagonalization procedure and WKB analysis, we derive representation of solutions in the phase space. Then, sharp decay properties in a framework of $L^p-L^q$ are investigated via these representations. Particularly, some thresholds for the regularity-loss type decay properties are found.
Colloids are often in forms of inorganic and organic particles whose particle sizes (dp) are ranging from 1.0 nm to 10.0 μm. On the one hand, their transport processes in the hyporheic zone such as deposition, resuspension, clogging and release are substantially affected by hyporheic exchange. On the other hand, the existence of colloids can modify the hydraulic structure of the hyporheic zone due to clogging. Despite the general acknowledgement that particle size plays an important role in contaminant adsorption and clogging, it remains unclear how the particle size of colloids changes during their transport processes in the hyporheic zone. This study aims to investigate the variation of the particle size of colloids in the overlying water and the effects of settlement and convection-diffusion via laboratory experiment and numerical simulation. The results show that both settlement and convection-diffusion play roles in the exchange of colloids between the stream and the streambed. More specifically, settlement is the dominant factor affecting the exchange process of large-sized particles (dp > 3.06 μm) in the hyporheic zone as the high settling velocity dominates the outflux of colloids in the overlying water; the exchange process of small-sized particles (dp < 1.10 μm) is more affected by convection-diffusion and some of them can be released from the streambed to the overlying water; while the exchange process of middle-sized particles (1.10 μm < dp < 3.06 μm) is affected by both convection-diffusion and settlement. Thus, this study may provide important insights into the variation of the particle size of colloids in the overlying water and the effects of settlement and convection-diffusion.
The out-of-plane displacement (OPD) of a circular dielectric elastomer actuator (DEA) membrane has been explored in recent years for a variety of important applications. Circular DEAs consist of an elastomer membrane that is prestretched to a rigid frame and coated with compliant electrodes. Such a simple configuration has found many interesting applications such as in, pumps, pulse tracking, hopping search and rescue robots, dielectric elastomer (DE) generators for renewable energy harvesting, linear actuators, and many others. Here, we present an easy-to-follow implementation of the OPD equations for circular DEAs via a detailed numerical solution using the shooting method (SM) on a system of differential algebraic equations (DAE), based on previous theoretical work. The SM numerical solution to the system of DAEs is applied to a practical range of values based on the reported literature. Analysis of the results and comparison against other studies are provided. The current work provides a go-to framework for implementation in further research and development.
Background: Left ventricular (LV) outflow tract (LVOT) obstruction increases mortality in patients undergoing transcatheter mitral valve implantation (TMVI) in degenerated bioprostheses, annuloplasty rings, and native mitral valves. We aimed to evaluate the left ventricular outflow tract area after TMVI using 3-diensional (3D) transesophageal echocardiography (TEE) and to investigate the pre-procedural cardiac geometry affects the LVOT area after TMVI. Methods: We retrospectively reviewed echocardiography data in 43 patients who had TMVI. A change in pressure gradient across LVOT from before to after TMVI (∆PG) and post-procedure 3D cross sectional area (CSA) at the level of the most distal portion of the mitral valve stent that was closest to the LV apex were assessed as evidence of LVOT narrowing. Results: TMVI with the use of balloon-expandable valve system was performed for 24 bioprostheses, 7 annuloplasty rings, and 12 native valves. Compared to patients without increase in LVOT gradient (∆PG <10 mmHg; n=33), patients with increase in LVOT gradient (∆PG ≥10 mmHg; n=10) had smaller LV end-systolic volume (LVESV), greater LV ejection fraction (LVEF) and smaller aorto-mitral (AM) angle. CSA at the valve stent distal edge showed strong association with ∆PG (r=-0.68, P<0.0001). Only small AM angle was associated with small CSA at the valve stent ventricular edge on multivariable analysis, independent of LVESV and LVEF. Conclusion: Pre-procedural AM angle as well as LVESV and LVEF were associated with LVOT narrowing in patients undergoing transcatheter mitral valve-in-valve, valve-in-ring, and valve-in-native valve implantation. These data may be useful for preprocedural planning.
Purpose: To observe and describe the stiffness changes of the optic nerve in the patients with multiple sclerosis (MS) with or without optic neuritis and healthy adults via shear wave elastography (SWE). Methods: Seventy optic nerves from thirty-five patients with MS and sixty optic nerves from thirty healthy subjects were included prospectively in the study. The optic nerve (ON), optic disc (OD), and perineural area were evaluated with SWE and optic nerve sheat diameter (ONSD) was measured by ultrasound. Results The mean age of patients was 39.68 ± 9.99 years. There was no statistically significant difference between the groups in terms of ONSD, SWE ON, SWE OD, and SWE perineural area levels (p> 0.05). In the MS group; No statistically significant difference was found between patients with and without optic neuritis for the mean age, gender distribution, duration of MS, types of MS, ONSD, SWE ON, SWE OD, SWE perineural area, and Expanded Disability Status Scale (EDSS) scores (p> 0.05). No statistically significant difference in terms of ONSD, SWE ON, SWE OD, and SWE perineural area between the MS patients with or without optic neuritis and the control group (p> 0.05). Conclusion: Shear wave elastography measurements of the optic nerve, optic disc, and perineural area do not contribute to the evaluation of optic neuritis in a patient with MS.
A new perspective of localized shear strain accumulation was proposed to elucidate the formation mechanism of fine granular area (FGA) generated in a high strength steel under very-high-cycle fatigue (VHCF). On the one hand, experiments of VHCF under the negative stress ratio of -1 was carried out, and the microstructure of FGA was found and characterized by using Scanning Electron Microscope, Transmission Electron Microscopy, and Transmission Kikuchi Diffraction. The results show that the FGA consists of high-density dislocations, sub-grains, and fine grains with high angle grain boundaries. On the other hand, the evolution of shear strain and fatigue damage at the vicinity of an inclusion was modelled by using crystal plasticity finite element method at both positive and negative stress ratios. The results show that although the overall strain in VHCF is negligible, significant shear strain is accumulated at the vicinity of the inclusion. Such a large local strain is the driving force for the formation of FGA. The results also suggest that with the accumulation of shear strain and damage, the positive stress ratio is gradually evolved into negative. This may explain why FGA has also been reported at positive stress ratios in some literatures.
Both termites and large mammalian herbivores (LMH) are savanna ecosystem engineers that have profound impacts on ecosystem structure and function. Both of these savanna engineers modulate many common and shared dietary resources such as woody and herbaceous plant biomass, yet few studies have addressed how they impact one another. In particular, it is unclear how herbivores may influence the abundance of long-lived termite mounds via changes in termite dietary resources such as woody and herbaceous biomass. While it has long been assumed that abundance and areal cover of termite mounds in the landscape remains relatively stable, most data are observational, and few experiments have tested how termite mound patterns may respond to biotic factors such as changes in large herbivore communities. Here, we use a broad tree density gradient and two landscape-scale experimental manipulations—the first a multi-guild large herbivore exclosure experiment and the second a tree removal experiment– to demonstrate that patterns in termite mound abundance and cover are unexpectedly dynamic. Termite mound abundance, but not areal cover not significantly, is positively associated with experimentally controlled presence of cattle, but not wild mesoherbivores (15-1000 kg) or megaherbivores (elephants and giraffes). Herbaceous productivity and tree density, termite dietary resources that significantly affected by different LMH treatments, are both positive predictors of termite mound abundance. Experimental reductions of tree densities are associated with lower abundances of termite mounds. These results reveal a richly interacting web of relationships among multiple savanna ecosystem engineers and suggest that termite mound abundance and areal cover is intimately tied to herbivore-driven resource availability.