562 research outputs found
Functional role of HLA class I cell-surface molecules in human T-lymphocyte activation and proliferation.
Orbital Mixer: Using Atomic Orbital Features for Basis Dependent Prediction of Molecular Wavefunctions
Leveraging ab initio data at scale has enabled the development of machine
learning models capable of extremely accurate and fast molecular property
prediction. A central paradigm of many previous works focuses on generating
predictions for only a fixed set of properties. Recent lines of research
instead aim to explicitly learn the electronic structure via molecular
wavefunctions from which other quantum chemical properties can directly be
derived. While previous methods generate predictions as a function of only the
atomic configuration, in this work we present an alternate approach that
directly purposes basis dependent information to predict molecular electronic
structure. The backbone of our model, Orbital Mixer, uses MLP Mixer layers
within a simple, intuitive, and scalable architecture and achieves competitive
Hamiltonian and molecular orbital energy and coefficient prediction accuracies
compared to the state-of-the-art
Evidence for a dual role for TC4 protein in regulating nuclear structure and cell cycle progression.
Wee1-Regulated Apoptosis Mediated by the Crk Adaptor Protein in Xenopus Egg Extracts
Many of the biochemical reactions of apoptotic cell death, including mitochondrial cytochrome c release and caspase activation, can be reconstituted in cell-free extracts derived from Xenopus eggs. In addition, because caspase activation does not occur until the egg extract has been incubated for several hours on the bench, upstream signaling processes occurring before full apoptosis are rendered accessible to biochemical manipulation. We reported previously that the adaptor protein Crk is required for apoptotic signaling in egg extracts (Evans, E.K., W. Lu, S.L. Strum, B.J. Mayer, and S. Kornbluth. 1997. EMBO (Eur. Mol. Biol. Organ.) J. 16:230–241). Moreover, we demonstrated that removal of Crk Src homology (SH)2 or SH3 interactors from the extracts prevented apoptosis. We now report the finding that the relevant Crk SH2-interacting protein, important for apoptotic signaling in the extract, is the well-known cell cycle regulator, Wee1. We have demonstrated a specific interaction between tyrosine-phosphorylated Wee1 and the Crk SH2 domain and have shown that recombinant Wee1 can restore apoptosis to an extract depleted of SH2 interactors. Moreover, exogenous Wee1 accelerated apoptosis in egg extracts, and this acceleration was largely dependent on the presence of endogenous Crk protein. As other Cdk inhibitors, such as roscovitine and Myt1, did not act like Wee1 to accelerate apoptosis, we propose that Wee1–Crk complexes signal in a novel apoptotic pathway, which may be unrelated to Wee1's role as a cell cycle regulator
Evidence for a shared HLA-A intralocus determinant defined by monoclonal antibody 131.
Factors Associated With Short- and Long-Term Outcomes of Therapy for Crohn’s Disease
Background & AimsOur post hoc analysis assessed the association of early (at weeks 26–30) clinical, endoscopic, biologic, and pharmacokinetic outcomes with corticosteroid-free remission at week 50 (CSFR50); CSFR50 was observed in 55.2% and 65.4% of patients treated with infliximab, alone or in combination with azathioprine, respectively.MethodsWe analyzed data from 203 patients: 96 received infliximab monotherapy and 107 received combination therapy. Receiver operating characteristic analysis was used to set cut-off points for the week 30 trough serum infliximab concentration (SIC30) and percentage change, from baseline, in the C-reactive protein (CRP) level at week 26, to predict CSFR50. Univariate and multivariate procedures analyzed predictive parameters of CSFR50 (odds ratio [OR] and 95% confidence interval [CI]). Mucosal healing (MH, zero ulcers) and CRP normalization (<8.0 mg/L) also were assessed.ResultsTrough SIC30 was higher in patients with than without CSFR50. Patients given combination therapy had higher trough SIC30s than those given monotherapy. Median trough SIC30 was significantly higher in patients with than without CSFR50 among those on infliximab monotherapy (2.14 vs 0.80 μg/mL; P = .006), but not for those on combination therapy (3.56 vs 3.54 μg/mL; P=.31). In patients with increased baseline levels of CRP (n = 120), corticosteroid-free remission at week 26 (CSFR26) (OR, 4.09; 95% CI, 1.65–10.11), and trough SIC30s of 3.0 μg/mL or greater (OR, 3.20; 95% CI, 1.38–7.42) were associated significantly with CSFR50. In patients evaluable for MH (n = 123), trough SIC30s of 3.0 μg/mL or greater (OR, 3.34; 95% CI, 1.53–7.28) and CRP normalization (OR, 2.69; 95% CI, 1.10–6.54) were associated significantly with MH at week 26 (MH26). Furthermore, CSFR26 (OR, 4.43; 95% CI, 1.81–10.82) and MH26 (OR, 3.01; 95% CI, 1.33–6.81) were associated significantly with CSFR50.ConclusionsTrough SIC30 is associated positively with MH26; CSFR26 and MH26 are independent predictors of CSFR50. Trough SIC30 of 3.0 μg/mL or greater early during maintenance treatment is an important determinant of clinical and endoscopic Crohn’s disease outcomes. ClinicalTrials.gov number, NCT00094458
Human Enteric Microsomal CYP4F Enzymes O-Demethylate the Antiparasitic Prodrug Pafuramidine
CYP4F enzymes, including CYP4F2 and CYP4F3B, were recently shown to be the major enzymes catalyzing the initial oxidative O-demethylation of the antiparasitic prodrug pafuramidine (DB289) by human liver microsomes. As suggested by a low oral bioavailability, DB289 could undergo first-pass biotransformation in the intestine, as well as in the liver. Using human intestinal microsomes (HIM), we characterized the enteric enzymes that catalyze the initial O-demethylation of DB289 to the intermediate metabolite, M1. M1 formation in HIM was catalyzed by cytochrome P450 (P450) enzymes, as evidenced by potent inhibition by 1-aminoben-zotriazole and the requirement for NADPH. Apparent Km and Vmax values ranged from 0.6 to 2.4 μM and from 0.02 to 0.89 nmol/min/mg protein, respectively (n = 9). Of the P450 chemical inhibitors evaluated, ketoconazole was the most potent, inhibiting M1 formation by 66%. Two inhibitors of P450-mediated arachidonic acid metabolism, HET0016 (N-hydroxy-N′-(4-n-butyl-2-methylphenyl)formamidine) and 17-octadecynoic acid, inhibited M1 formation in a concentration-dependent manner (up to 95%). Immunoinhibition with an antibody raised against CYP4F2 showed concentration-dependent inhibition of M1 formation (up to 92%), whereas antibodies against CYP3A4/5 and CYP2J2 had negligible to modest effects. M1 formation rates correlated strongly with arachidonic acid ω-hydroxylation rates (r2 = 0.94, P < 0.0001, n = 12) in a panel of HIM that lacked detectable CYP4A11 protein expression. Quantitative Western blot analysis revealed appreciable CYP4F expression in these HIM, with a mean (range) of 7 (3–18) pmol/mg protein. We conclude that enteric CYP4F enzymes could play a role in the first-pass biotransformation of DB289 and other xenobiotics
Set optimization - a rather short introduction
Recent developments in set optimization are surveyed and extended including
various set relations as well as fundamental constructions of a convex analysis
for set- and vector-valued functions, and duality for set optimization
problems. Extensive sections with bibliographical comments summarize the state
of the art. Applications to vector optimization and financial risk measures are
discussed along with algorithmic approaches to set optimization problems
Vedolizumab for the Treatment of Adults with Moderate-to-Severe Active Ulcerative Colitis: An Evidence Review Group Perspective of a NICE Single Technology Appraisal.
As part of its single technology appraisal (STA) process, the National Institute for Health and Care Excellence (NICE) invited the manufacturer of vedolizumab (Takeda UK) to submit evidence of the clinical effectiveness and cost effectiveness of vedolizumab for the treatment of patients with moderate-to-severe active ulcerative colitis (UC). The Evidence Review Group (ERG) produced a critical review of the evidence for the clinical effectiveness and cost effectiveness of the technology, based upon the company's submission to NICE. The evidence was derived mainly from GEMINI 1, a Phase 3, multicentre, randomised, double-blinded, placebo-controlled study of the induction and maintenance of clinical response and remission by vedolizumab (MLN0002) in patients with moderate-to-severe active UC with an inadequate response to, loss of response to or intolerance of conventional therapy or anti-tumour necrosis factor (TNF)-α. The clinical evidence showed that vedolizumab performed significantly better than placebo in both the induction and maintenance phases. In the post hoc subgroup analyses in patients with or without prior anti-TNF-α therapy, vedolizumab performed better then placebo (p value not reported). In addition, a greater improvement in health-related quality of life was observed in patients treated with vedolizumab, and the frequency and types of adverse events were similar in the vedolizumab and placebo groups, but the evidence was limited to short-term follow-up. There were a number of limitations and uncertainties in the clinical evidence base, which warrants caution in its interpretation-in particular, the post hoc subgroup analyses and high dropout rates in the maintenance phase of GEMINI 1. The company also presented a network meta-analysis of vedolizumab versus other biologic therapies indicated for moderate-to-severe UC. However, the ERG considered that the results presented may have underestimated the uncertainty in treatment effects, since fixed-effects models were used, despite clear evidence of heterogeneity among the trials included in the network. Results from the company's economic evaluation (which included price reductions to reflect the proposed patient access scheme for vedolizumab) suggested that vedolizumab is the most effective option compared with surgery and conventional therapy in the following three populations: (1) a mixed intention-to-treat population, including patients who have previously received anti-TNF-α therapy and those who are anti-TNF-α naïve; (2) patients who are anti-TNF-α naïve only; and (3) patients who have previously failed anti-TNF-α therapy only. The ERG concluded that the results of the company's economic evaluation could not be considered robust, because of errors in model implementation, omission of relevant comparators, deviations from the NICE reference case and questionable model assumptions. The ERG amended the company's model and demonstrated that vedolizumab is expected to be dominated by surgery in all three populations
Both early and delayed anti-CD40L antibody treatment induces a stable plaque phenotype
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