While chemotherapy delivery by nanocarriers has modestly improved the survival prospects of pancreatic ductal adenocarcinoma (PDAC), additional engagement of the immune response could be game ...changing. We demonstrate a nano-enabled approach for accomplishing robust anti-PDAC immunity in syngeneic mice through the induction of immunogenic cell death (ICD) as well as interfering in the immunosuppressive indoleamine 2,3-dioxygenase (IDO) pathway. This is accomplished by conjugating the IDO inhibitor, indoximod (IND), to a phospholipid that allows prodrug self-assembly into nanovesicles or incorporation into a lipid bilayer that encapsulates mesoporous silica nanoparticles (MSNP). The porous MSNP interior allows contemporaneous delivery of the ICD-inducing chemotherapeutic agent, oxaliplatin (OX). The nanovesicles plus free OX or OX/IND-MSNP induce effective innate and adaptive anti-PDAC immunity when used in a vaccination approach, direct tumor injection or intravenous biodistribution to an orthotopic PDAC site. Significant tumor reduction or eradication is accomplishable by recruiting cytotoxic T lymphocytes, concomitant with downregulation of Foxp3
T cells.
Achieving stability with highly active Ru nanoparticles for electrocatalysis is a major challenge for the oxygen evolution reaction. As improved stability of Ru catalysts has been shown for bulk ...surfaces with low‐index facets, there is an opportunity to incorporate these stable facets into Ru nanoparticles. Now, a new solution synthesis is presented in which hexagonal close‐packed structured Ru is grown on Au to form nanoparticles with 3D branches. Exposing low‐index facets on these 3D branches creates stable reaction kinetics to achieve high activity and the highest stability observed for Ru nanoparticle oxygen evolution reaction catalysts. These design principles provide a synthetic strategy to achieve stable and active electrocatalysts.
Au‐Ru nanoparticles with 3D and faceted branches are synthesized using a new approach for bimetallic systems. The well‐defined structure enables record high stability for Ru electrocatalysts to be achieved while retaining high activity in the oxygen evolution reaction.
Summary
Cassava (Manihot esculenta Crantz) is one of the important staple foods in Sub‐Saharan Africa. It produces starchy storage roots that provide food and income for several hundred million ...people, mainly in tropical agriculture zones. Increasing cassava storage root and starch yield is one of the major breeding targets with respect to securing the future food supply for the growing population of Sub‐Saharan Africa. The Cassava Source–Sink (CASS) project aims to increase cassava storage root and starch yield by strategically integrating approaches from different disciplines. We present our perspective and progress on cassava as an applied research organism and provide insight into the CASS strategy, which can serve as a blueprint for the improvement of other root and tuber crops. Extensive profiling of different field‐grown cassava genotypes generates information for leaf, phloem, and root metabolic and physiological processes that are relevant for biotechnological improvements. A multi‐national pipeline for genetic engineering of cassava plants covers all steps from gene discovery, cloning, transformation, molecular and biochemical characterization, confined field trials, and phenotyping of the seasonal dynamics of shoot traits under field conditions. Together, the CASS project generates comprehensive data to facilitate conventional breeding strategies for high‐yielding cassava genotypes. It also builds the foundation for genome‐scale metabolic modelling aiming to predict targets and bottlenecks in metabolic pathways. This information is used to engineer cassava genotypes with improved source–sink relations and increased yield potential.
Significance Statement
Cassava (Manihot esculenta) is one of the most important staple food crops in Sub‐Sahran Africa. The Cassava Source‐Sink project aims to boost cassava storage root yield by simultaneously improving the plants source, transport and sink capacity.
Objective:
The study was undertaken to determine the pathologic basis of subtle abnormalities in magnetization transfer ratio (MTR) and diffusion tensor imaging (DTI) parameters observed in ...normal‐appearing white matter (NAWM) in multiple sclerosis brains.
Methods:
Brain tissues were obtained through a rapid postmortem protocol that included in situ magnetic resonance imaging (MRI). Four types of MRI‐defined regions of interest (ROIs) were analyzed: (1) regions that were abnormal on all images (T2T1MTR lesions); (2) NAWM regions with slightly abnormal MTR located close to white matter lesions (sa‐WM Close); (3) NAWM regions with slightly abnormal MTR located far from lesions (sa‐WM Far); and (4) NAWM regions with normal MTR (NAWM). Immunohistochemical analysis for each ROI comprised immunostaining for myelin, axonal markers, activated microglia/macrophages, astrocytes, plasma proteins, and blood vessels.
Results:
Forty‐eight ROIs from 4 secondary progressive MS brains were analyzed. sa‐WM Close ROIs were associated with significantly more axonal swellings. There were more enlarged major histocompatibility complex II+ microglia and macrophages detected in sa‐WM Far, sa‐WM Close, and T2T1MTR lesions than in NAWM. Across all ROIs, MTR and DTI measures were moderately correlated with myelin density, axonal area, and axonal counts. Excluding T2T1MTR lesions from analysis revealed that MTR and DTI measures in nonlesional white matter (WM) were correlated with activated microglia, but not with axonal or myelin integrity.
Interpretation:
The pathologic substrates for MRI abnormalities in NAWM vary based on distance from focal WM lesions. Close to WM lesions, axonal pathology and microglial activation may explain subtle MRI changes. Distant from lesions, microglial activation associated with proximity to cortical lesions might underlie MRI abnormalities. ANN NEUROL 2011
Development of biotherapeutics is hampered by the inherent risk of immunogenicity, which requires extensive clinical assessment and possible re-engineering efforts for mitigation. The focus in the ...pre-clinical phase is to determine the likelihood of developing treatment-emergent anti-drug antibodies (TE-ADA) and presence of pre-existing ADA in drug-naïve individuals as risk-profiling strategies. Pre-existing ADAs are routinely identified during clinical immunogenicity assessment, but their origin and impact on drug safety and efficacy have not been fully elucidated. One specific class of pre-existing ADAs has been described, which targets neoepitopes of antibody fragments, including Fabs, VH, or VHH domains in isolation from their IgG context. With the increasing number of antibody fragments and other small binding scaffolds entering the clinic, a widely applicable method to mitigate pre-existing reactivity against these molecules is desirable. Here is described a structure-based engineering approach to abrogate pre-existing ADA reactivity to the C-terminal neoepitope of VH(H)s. On the basis of 3D structures, small modifications applicable to any VH(H) are devised that would not impact developability or antigen binding. In-silico B cell epitope mapping algorithms were used to rank the modified VHH variants by antigenicity; however, the limited discriminating capacity of the computational methods prompted an experimental evaluation of the engineered molecules. The results identified numerous modifications capable of reducing pre-existing ADA binding. The most efficient consisted of the addition of two proline residues at the VHH C-terminus, which led to no detectable pre-existing ADA reactivity while maintaining favorable developability characteristics. The method described, and the modifications identified thereby, may provide a broadly applicable solution to mitigate immunogenicity risk of antibody-fragments in the clinic and increase safety and efficacy of this promising new class of biotherapeutics.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background Chronic rhinosinusitis with nasal polyps is associated with local immunoglobulin hyperproduction and the presence of IgE antibodies against Staphylococcus aureus enterotoxins (SAEs). ...Aspirin-exacerbated respiratory disease is a severe form of chronic rhinosinusitis with nasal polyps in which nearly all patients express anti-SAEs. Objectives We aimed to understand antibodies reactive to SAEs and determine whether they recognize SAEs through their complementarity-determining regions (CDRs) or framework regions. Methods Labeled staphylococcal enterotoxin (SE) A, SED, and SEE were used to isolate single SAE-specific B cells from the nasal polyps of 3 patients with aspirin-exacerbated respiratory disease by using fluorescence-activated cell sorting. Recombinant antibodies with “matched” heavy and light chains were cloned as IgG1 , and those of high affinity for specific SAEs, assayed by means of ELISA and surface plasmon resonance, were recloned as IgE and antigen-binding fragments. IgE activities were tested in basophil degranulation assays. Results Thirty-seven SAE-specific, IgG- or IgA-expressing B cells were isolated and yielded 6 anti-SAE clones, 2 each for SEA, SED, and SEE. Competition binding assays revealed that the anti-SEE antibodies recognize nonoverlapping epitopes in SEE. Unexpectedly, each anti-SEE mediated SEE-induced basophil degranulation, and IgG1 or antigen-binding fragments of each anti-SEE enhanced degranulation by the other anti-SEE. Conclusions SEEs can activate basophils by simultaneously binding as antigens in the conventional manner to CDRs and as superantigens to framework regions of anti-SEE IgE in anti-SEE IgE-FcεRI complexes. Anti-SEE IgG1 s can enhance the activity of anti-SEE IgEs as conventional antibodies through CDRs or simultaneously as conventional antibodies and as “superantibodies” through CDRs and framework regions to SEEs in SEE–anti-SEE IgE-FcεRI complexes.
A significant proportion of individuals develop recurrent Clostridium difficile infection (CDI) following initial disease. Fecal microbiota transplantation (FMT), a highly effective treatment method ...for recurrent CDI, has been demonstrated to induce microbiota recovery. One of the proposed functions associated with restoration of colonization resistance against C. difficile has been recovery of bile acid metabolism. In this study, we aimed to assess recovery of short chain fatty acids (SCFAs) in addition to bile acids alongside microbial community structure in six patients with recurrent CDI following treatment with FMT over time. Using 16S rRNA gene-based sequencing, we observed marked similarity of the microbiota between recipients following FMT (n = 6, sampling up to 6 months post-FMT) and their respective donors. Sustained increases in the levels of the SCFAs butyrate, acetate, and propionate were observed post-FMT, and variable recovery over time was observed in the secondary bile acids deoxycholate and lithocholate. To correlate these changes with specific microbial taxa at an individual level, we applied a generalized estimating equation approach to model metabolite concentrations with the presence of specific members of the microbiota. Metabolites that increased following FMT were associated with bacteria classified within the Lachnospiraceae, Ruminococcaceae, and unclassified Clostridiales families. In contrast, members of these taxa were inversely associated with primary bile acids. The longitudinal aspect of this study allowed us to characterize individualized patterns of recovery, revealing variability between and within patients following FMT.
•Short chain fatty acids and bile acids are increased following FMT.•Transplantation of microbes following FMT is highly individualistic.•Broad classifications of microbes are correlated with metabolite production.
The mitochondrial electron transport chain (ETC) is a highly adaptive process to meet metabolic demands of the cell, and its dysregulation has been associated with diverse clinical pathologies. ...However, the role and nature of impaired ETC in kidney diseases remains poorly understood. Here, we generate diabetic mice with podocyte-specific overexpression of Ndufs4, an accessory subunit of mitochondrial complex I, as a model investigate the role of ETC integrity in diabetic kidney disease (DKD). We find that conditional male mice with genetic overexpression of Ndufs4 exhibit significant improvements in cristae morphology, mitochondrial dynamics, and albuminuria. By coupling proximity labeling with super-resolution imaging, we also identify the role of cristae shaping protein STOML2 in linking NDUFS4 with improved cristae morphology. Together, we provide the evidence on the central role of NDUFS4 as a regulator of cristae remodeling and mitochondrial function in kidney podocytes. We propose that targeting NDUFS4 represents a promising approach to slow the progression of DKD.
Background
Modification of guideline‐directed medical therapy (GDMT) in hospitalized patients with heart failure (HF) has not been extensively evaluated.
Methods
The community surveillance arm of the ...Atherosclerosis Risk in Communities Study identified 6959 HF hospitalizations from 2005–2011. Predictors of GDMT modification and survival were assessed using multivariable logistic regression and Cox proportional hazards models.
Results
For 5091 hospitalizations, patient mean age was 75 years, 53% were female, 69% were white, and 81% had acute decompensated heart failure (ADHF). Regarding ejection fraction (EF), 31% of patients had HF with reduced EF (HFrEF), 24% had HF with preserved EF (HFpEF), and 44% were missing EF values. At admission, 52% of patients received angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers (ACEIs/ARBs), 66% β‐blockers (BBs), 9% aldosterone‐receptor antagonists, 16% digoxin, 10% hydralazine, and 29% nitrates. Modification of GDMT occurred in up to 23% of hospitalizations. Significant predictors of GDMT initiation included ADHF and HFrEF; discontinuation of medications was observed with select comorbidities. In HFrEF, initiation of any GDMT was associated with reduced 1‐year all‐cause mortality (adjusted hazard ratio HR 0.41, 95% confidence interval CI 0.23–0.71) as was initiation of ACEI/ARBs, BBs, and digoxin. Discontinuation of any therapy versus maintaining GDMT was associated with greater mortality (HR 1.30, 95% CI 1.02–1.66). Similar trends were observed in HFpEF.
Conclusions
Our study suggests that GDMT initiation is associated with increased survival, and discontinuation of therapy is associated with reduced survival in hospitalized patients with HF. Future studies should be conducted to confirm the impact of GDMT therapy modification in this population.
Objective To develop a teaching and assessment tool for laparoscopic suturing and intracorporeal knot tying. Design and Setting We designed an Objective Structured Assessment of Technical Skills ...(OSATS) tool that includes a procedure-specific checklist (PSC) and global rating scale (GRS) to assess laparoscopic suturing and intracorporeal knot-tying performance. Obstetrics and Gynecology residents at our institution were videotaped while performing a laparoscopic suturing and intracorporeal knot-tying task at a surgical simulation workshop. A total of 2 expert reviewers assessed resident performance using the OSATS tool during live performance and 1 month later using the videotaped recordings. OSATS scores were analyzed using the Wilcoxon rank-sum test. Data are presented as median scores (interquartile range IQR). Intrarater and interrater reliabilities were assessed using a Spearman correlation and are presented as an r correlation coefficient and p value. An r ≥ 0.8 was considered as a high correlation. After testing, we received feedback from residents and faculty to improve the OSATS tool as part of an iterative design process. Participants In all, 14 of 21 residents (66.7%) completed the study, with 9 junior residents and 5 senior residents. Results Junior residents had a lower score on the PSC than senior residents did; however, this was not statistically significant (median = 6.0 IQR: 4.0-10.0 and median = 13.0 IQR: 10.0-13.0; p = 0.09). There was excellent intrarater reliability with our OSATS tool (for PSC component, r = 0.88 for Rater 1 and 0.93 for Rater 2, both p < 0.0001; for GRS component, r = 0.85 for Rater 1 and 0.88 for Rater 2, both p ≤ 0.0002). The PSC also has high interrater reliability during live evaluation ( r = 0.92; p < 0.0001), and during the videotape scoring with r = 0.77 (p = 0.001). Conclusions Our OSATS tool may be a useful assessment and teaching tool for laparoscopic suturing and intracorporeal knot-tying skills. Overall, good intrarater reliability was demonstrated, suggesting that this tool may be useful for longitudinal assessment of surgical skills.
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