Formation of CO2 on a carbonaceous surface: a quantum chemical study

The formation of CO2 in the gas phase and on a polyaromatic hydrocarbon surface (coronene) via three possible pathways is investigated with density functional theory. Calculations show that the coronene surface catalyses the formation of CO2 on model grain surfaces. The addition of O-3 to CO is activated by 2530 K in the gas phase. This barrier is lowered by 253 K for the Eley-Rideal mechanism and 952 K for the hot-atom mechanism on the surface of coronene. Alternative pathways for the formation of CO2 are the addition of O-3 to the HCO radical, followed by dissociation of the HCO2 intermediate. The O + HCO addition is barrierless in the gas phase and on the surface and is more than sufficiently exothermic to subsequently cleave the H-C bond. The third mechanism, OH + CO addition followed by H removal from the energized HOCO intermediate, has a gas-phase exit barrier that is 1160 K lower than the entrance barrier. On the coronene surface, however, both barriers are almost equal. Because the HOCO intermediate can also be stabilized by energy dissipation to the surface, it is anticipated that for the surface reaction the adsorbed HOCO could be a long-lived intermediate. In this case, the stabilized HOCO intermediate could react, in a barrierless manner, with a hydrogen atom to form H-2 + CO2, HCO2H, or H2O + CO

Helicobacter pylori infection associates with fecal microbiota composition and diversity

Helicobacter (H.) pylori is the most important cause for peptic ulcer disease and a risk factor for gastric carcinoma. How colonization with H. pylori affects the intestinal microbiota composition in humans is unknown. We investigated the association of H. pylori infection with intestinal microbiota composition in the population-based cohort Study-of-Health-in-Pomerania (SHIP)-TREND. Anti-H. pylori serology and H. pylori stool antigen tests were used to determine the H. pylori infection status. The fecal microbiota composition of 212 H. pylori positive subjects and 212 matched negative control individuals was assessed using 16S rRNA gene sequencing. H. pylori infection was found to be significantly associated with fecal microbiota alterations and a general increase in fecal microbial diversity. In infected individuals, the H. pylori stool antigen load determined a larger portion of the microbial variation than age or sex. The highest H. pylori stool antigen loads were associated with a putatively harmful microbiota composition. This study demonstrates profound alterations in human fecal microbiota of H. pylori infected individuals. While the increased microbiota diversity associated with H. pylori infection as well as changes in abundance of specific genera could be considered to be beneficial, others may be associated with adverse health effects, reflecting the complex relationship between H. pylori and its human host

Phase 1 Trial of Antibody NI006 for Depletion of Cardiac Transthyretin Amyloid

BACKGROUND Transthyretin amyloid (ATTR) cardiomyopathy is a progressive and fatal disease caused by misfolded transthyretin. Despite advances in slowing disease progression, there is no available treatment that depletes ATTR from the heart for the amelioration of cardiac dysfunction. NI006 is a recombinant human anti-ATTR antibody that was developed for the removal of ATTR by phagocytic immune cells. METHODS In this phase 1, double-blind trial, we randomly assigned (in a 2:1 ratio) 40 patients with wild-type or variant ATTR cardiomyopathy and chronic heart failure to receive intravenous infusions of either NI006 or placebo every 4 weeks for 4 months. Patients were sequentially enrolled in six cohorts that received ascending doses (ranging from 0.3 to 60 mg per kilogram of body weight). After four infusions, patients were enrolled in an open-label extension phase in which they received eight infusions of NI006 with stepwise increases in the dose. The safety and pharmacokinetic profiles of NI006 were assessed, and cardiac imaging studies were performed. RESULTS The use of NI006 was associated with no apparent drug-related serious adverse events. The pharmacokinetic profile of NI006 was consistent with that of an IgG antibody, and no antidrug antibodies were detected. At doses of at least 10 mg per kilogram, cardiac tracer uptake on scintigraphy and extracellular volume on cardiac magnetic resonance imaging, both of which are imaging-based surrogate markers of cardiac amyloid load, appeared to be reduced over a period of 12 months. The median N-terminal pro-B-type natriuretic peptide and troponin T levels also seemed to be reduced. CONCLUSIONS In this phase 1 trial of the recombinant human antibody NI006 for the treatment of patients with ATTR cardiomyopathy and heart failure, the use of NI006 was associated with no apparent drug-related serious adverse events. (Funded by Neurimmune; NI006-101 ClinicalTrials.gov number, NCT04360434.)

Nonalcoholic fatty liver disease, liver fibrosis, and structural brain imaging:The Cross-Cohort Collaboration

Background and purpose:Prior studies reported conflicting findings regarding the association of nonalcoholic fatty liver disease (NAFLD) and liver fibrosis with measures of brain health. We examined whether NAFLD and liver fibrosis are associated with structural brain imaging measures in middle- and old-age adults. Methods: In this cross-sectional study among dementia- and stroke-free individuals, data were pooled from the Offspring and Third Generation cohorts of the Framingham Heart Study (FHS), the Rotterdam Study (RS), and the Study of Health in Pomerania. NAFLD was assessed through abdominal imaging. Transient hepatic elastography (FibroScan) was used to assess liver fibrosis in FHS and RS. Linear regression models were used to explore the relation of NAFLD and liver fibrosis with brain volumes, including total brain, gray matter, hippocampus, and white matter hyperintensities, adjusting for potential confounders. Results were combined using fixed effects meta-analysis. Results:In total, 5660 and 3022 individuals were included for NAFLD and liver fibrosis analyses, respectively. NAFLD was associated with smaller volumes of total brain (β = −3.5, 95% confidence interval [CI] = −5.4 to −1.7), total gray matter (β = −1.9, 95% CI = −3.4 to −0.3), and total cortical gray matter (β = −1.9, 95% CI = −3.7 to −0.01). In addition, liver fibrosis (defined as liver stiffness measure ≥8.2 kPa) was related to smaller total brain volumes (β = −7.3, 95% CI = −11.1 to −3.5). Heterogeneity between studies was low. Conclusions:NAFLD and liver fibrosis may be directly related to brain aging. Larger and prospective studies are warranted to validate these findings and identify liver-related preventive strategies for neurodegeneration.</p

Toll-Like Receptor 1 Locus Re-examined in a Genome-Wide Association Study Update on Anti–Helicobacter pylori IgG Titers

Funding Information: Funding The Rotterdam Study I-II was supported by the Netherlands Organization of Scientific Research (NWO; 175.010.2005.011, 911-03-012), Research Institute for Diseases in the Elderly (RIDE; 014-93-015), Genomics Initiative/NWO (project no. 050-060-810), Erasmus Medical Center Rotterdam, Erasmus University Rotterdam, Netherlands Organization for the Health Research and Development (ZonMw), Ministry of Education, Culture, and Science and Ministry for Health, Welfare, and Sports, European Commission, and the Municipality of Rotterdam. GenerationR was supported by Erasmus Medical Center Rotterdam, Erasmus University Rotterdam, ZonMw (907.00303, 916.10159), NWO, and the Ministry for Health, Welfare and Sports. The Study of Health in Pomerania (SHIP) and SHIP-TREND were supported by Deutsche Krebshilfe/Dr Mildred-Scheel-Stiftung (109102), Deutsche Forschungsgemeinschaft (DFG GRK840-D2/E3/E4, MA 4115/1-2/3), Federal Ministry of Education and Research (BMBF GANI-MED 03IS2061A and BMBF 0314107, 01ZZ9603, 01ZZ0103, 01ZZ0403, 03ZIK012), the European Union (EU-FP-7-EPCTM and EU-FP7-REGPOT-2010-1), AstraZeneca (unrestricted grant), the Federal Ministry of Education and Research, Siemens Healthcare, the Federal State of Mecklenburg–West Pomerania, and the University of Greifswald. The Framingham Heart Study was supported by National Institutes of Health grants N01-HC-25195, HHSN268201500001I, and 75N92019D00031 (to Boston University) and the Division of Intramural Research, National Heart, Lung, and Blood Institute (NHLBI). The Multi-Ethnic Study of Atherosclerosis (MESA) and the MESA SHARe projects were supported by the NHLBI (75N92020D00001, HHSN268201500003I, N01-HC-95159, 75N92020D00005, N01-HC-95160, 75N92020D00002, N01-HC-95161, 75N92020D00003, N01-HC-95162, 75N92020D00006, N01-HC-95163, 75N92020D00004, N01-HC-95164, 75N92020D00007, N01-HC-95165, N01-HC-95166, N01-HC-95167, N01-HC-95168, N01-HC-95169, UL1-TR-000040, UL1-TR-001079, and UL1-TR-001420. Funding for SHARe genotyping was provided by NHLBI grant N02-HL-64278. Genotyping was performed at Affymetrix (Santa Clara, CA) and the Broad Institute of Harvard and MIT (Boston, MA) using the Affymetrix Genome-Wide Human SNP Array 6.0. The provision of genotyping data was supported in part by the National Center for Advancing Translational Sciences grant UL1TR001881, and the National Institute of Diabetes and Digestive and Kidney Disease Diabetes Research Center grant DK063491 to the Southern California Diabetes Endocrinology Research Center. The Epidemiological Investigations on Chances of Preventing Recognizing Early and Optimally Treating Chronic Diseases in an Elderly Population were supported by the State Ministry of Science, Research and Arts, Baden-Württemberg, Federal Ministry of Education and Research, and Federal Ministry of Family Affairs, Senior Citizens, Women and Youth. LATVIA was supported by the European Regional Development Fund (ERDF; 009/0220/1DP/1.1.1.2.0/09/APIA/VIAA/016), National Program for Research in Latvia, Ministry of Health (6-1396-2016), and Fundamental and Applied Research Projects Program in Latvia (project no. lzp-2018/1-0135). Funding Information: Conceptualization: Linda Broer, Manon C.W. Spaander, Fabian Frost, Stefan Weiss, Georg Homuth, Henry Völzke, Markus M. Lerch, Ben Schöttker, Hermann Brenner, Daniel Levy, Shih-Jen Hwang, Alexis C. Wood, Stephen S. Rich, Jerome I. Rotter, Kent D. Taylor, Russell P. Tracy, Edmond K. Kabagambe, Marcis Leja, Janis Klovins, Raitis Peculis, Dace Rudzite, Liene Nikitina-Zake, Girts Skenders, Vita Rovite, André Uitterlinden, Ernst J. Kuipers, Maikel P. Peppelenbosch, and additional members of Rotterdam Study I-II, GenerationR, Study of Health in Pomerania, Framingham Heart Study, Multi-Ethnic Study of Atherosclerosis, Epidemiological Investigations on Chances of Preventing Recognizing Early and Optimally Treating Chronic Diseases in an Elderly Population, and LATVIA cohorts not directly involved in this manuscript. Methodology: all authors. Investigation: all authors. Formal analysis of discovery: Linda Broer, Fabian Frost, Stefan Weiss, Georg Homuth, Henry Völzke, Markus M. Lerch, Daniel Levy, Shih-Jen Hwang, Alexis C. Wood, Stephen S. Rich, Jerome I. Rotter, Kent D. Taylor, Russell P. Tracy, and Edmond K. Kabagambe. Formal analysis of replication: Yan Zhang, Hannah Stocker, Hermann Brenner, Marcis Leja, Janis Klovins, and Raitis Peculis. Formal analysis of meta-analysis: Linda Broer. Project administration: Suk Yee Lam and Gwenny M. Fuhler. Resources: Fabian Frost, Stefan Weiss, Georg Homuth, Henry Völzke, Markus M. Lerch, Hermann Brenner, Daniel Levy, Shih-Jen Hwang, Alexis C. Wood, Stephen S. Rich, Jerome I. Rotter, Kent D. Taylor, Russell P. Tracy, Edmond K. Kabagambe, Marcis Leja, Janis Klovins, Dace Rudzite, Liene Nikitina-Zake, Girts Skenders, Vita Rovite, Ernst J. Kuipers, and Maikel P. Peppelenbosch. Supervision: Manon C.W. Spaander, Fabian Frost, Stefan Weiss, Georg Homuth, Henry Völzke, Markus M. Lerch, Hermann Brenner, Daniel Levy, Shih-Jen Hwang, Alexis C. Wood, Stephen S. Rich, Jerome I. Rotter, Kent D. Taylor, Russell P. Tracy, Edmond K. Kabagambe, Marcis Leja, Janis Klovins, Gwenny M. Fuhler, Maikel P. Peppelenbosch, and André Uitterlinden. Visualization: Suk Yee Lam, Michiel C. Mommersteeg, Bingting Yu, Linda Broer, and Gwenny M. Fuhler. Writing—original draft: Suk Yee Lam, Michiel C. Mommersteeg, and Gwenny M. Fuhler. Writing—reviewing and editing: all authors. Publisher Copyright: © 2022 The Author(s)Background & Aims: A genome-wide significant association between anti–Helicobacter pylori (H pylori) IgG titers and Toll-like receptor (TLR1/6/10) locus on 4p14 was demonstrated for individuals of European ancestry, but not uniformly replicated. We re-investigated this association in an updated genome-wide association study (GWAS) meta-analysis for populations with low gastric cancer incidence, address potential causes of cohort heterogeneity, and explore functional implications of genetic variation at the TLR1/6/10 locus. Methods: The dichotomous GWAS (25% individuals exhibiting highest anti–H pylori IgG titers vs remaining 75%) included discovery and replication sampls of, respectively, n = 15,685 and n = 9676, all of European ancestry. Longitudinal analysis of serologic data was performed on H pylori–eradicated subjects (n = 132) and patients under surveillance for premalignant gastric lesions (n = 107). TLR1/6/10 surface expression, TLR1 mRNA, and cytokine levels were measured in leukocyte subsets of healthy subjects (n = 26) genotyped for TLR1/6/10 variants. Results: The association of the TLR1/6/10 locus with anti–H pylori IgG titers (rs12233670; β = −0.267 ± SE 0.034; P = 4.42 × 10−15) presented with high heterogeneity and failed replication. Anti–H pylori IgG titers declined within 2–4 years after eradication treatment (P = 0.004), and decreased over time in patients with premalignant gastric lesions (P < 0.001). Variation at the TLR1/6/10 locus affected TLR1-mediated cytokine production and TLR1 surface expression on monocytes (P = 0.016) and neutrophils (P = 0.030), but not mRNA levels. Conclusions: The association between anti–H pylori IgG titers and TLR1/6/10 locus was not replicated across cohorts, possibly owing to dependency of anti–H pylori IgG titers on therapy, clearance, and antibody decay. H pylori–mediated immune cell activation is partly mediated via TLR1 signaling, which in turn is affected by genetic variation.publishersversionPeer reviewe

Survival benefit with checkpoint inhibitors versus chemotherapy is modified by brain metastases in patients with recurrent small cell lung cancer

IntroductionSmall cell lung cancer (SCLC) is a rapidly growing malignancy with early distant metastases. Up to 70% will develop brain metastases, and the poor prognosis of these patients has not changed considerably. The potential of checkpoint inhibitors (CPI) in treating recurrent (r/r) SCLC and their effect on brain metastases remain unclear.MethodsIn this retrospective multicenter study, we analyzed r/r SCLC patients receiving second or further-line CPI versus chemotherapy between 2010 and 2020. We applied multivariable-adjusted Cox regression analysis to test for differences in 1-year mortality and real-world progression. We then used interaction analysis to evaluate whether brain metastases (BM) and/or cranial radiotherapy (CRT) modified the effect of CPI versus chemotherapy on overall survival.ResultsAmong 285 patients, 99 (35%) received CPI and 186 (65%) patients received chemotherapy. Most patients (93%) in the CPI group received nivolumab/ipilimumab. Chemotherapy patients were entirely CPI-naïve and only one CPI patient had received atezolizumab for first-line treatment. CPI was associated with a lower risk of 1-year mortality (adjusted Hazard Ratio [HRadj] 0.59, 95% CI 0.42 to 0.82, p=0.002). This benefit was modified by BM and CRT, indicating a pronounced effect in patients without BM (with CRT: HRadj 0.34, p=0.003; no CRT: HRadj 0.50, p=0.05), while there was no effect in patients with BM who received CRT (HRadj 0.85, p=0.59).ConclusionCPI was associated with a lower risk of 1-year mortality compared to chemotherapy. However, the effect on OS was significantly modified by intracranial disease and radiotherapy, suggesting the benefit was driven by patients without BM

Large-scale association analyses identify host factors influencing human gut microbiome composition

To study the effect of host genetics on gut microbiome composition, the MiBioGen consortium curated and analyzed genome-wide genotypes and 16S fecal microbiome data from 18,340 individuals (24 cohorts). Microbial composition showed high variability across cohorts: only 9 of 410 genera were detected in more than 95% of samples. A genome-wide association study of host genetic variation regarding microbial taxa identified 31 loci affecting the microbiome at a genome-wide significant (P <5 x 10(-8)) threshold. One locus, the lactase (LCT) gene locus, reached study-wide significance (genome-wide association study signal: P = 1.28 x 10(-20)), and it showed an age-dependent association with Bifidobacterium abundance. Other associations were suggestive (1.95 x 10(-10) <P <5 x 10(-8)) but enriched for taxa showing high heritability and for genes expressed in the intestine and brain. A phenome-wide association study and Mendelian randomization identified enrichment of microbiome trait loci in the metabolic, nutrition and environment domains and suggested the microbiome might have causal effects in ulcerative colitis and rheumatoid arthritis

Meta-analysis of human genome-microbiome association studies: the MiBioGen consortium initiative

Abstract Background In recent years, human microbiota, especially gut microbiota, have emerged as an important yet complex trait influencing human metabolism, immunology, and diseases. Many studies are investigating the forces underlying the observed variation, including the human genetic variants that shape human microbiota. Several preliminary genome-wide association studies (GWAS) have been completed, but more are necessary to achieve a fuller picture. Results Here, we announce the MiBioGen consortium initiative, which has assembled 18 population-level cohorts and some 19,000 participants. Its aim is to generate new knowledge for the rapidly developing field of microbiota research. Each cohort has surveyed the gut microbiome via 16S rRNA sequencing and genotyped their participants with full-genome SNP arrays. We have standardized the analytical pipelines for both the microbiota phenotypes and genotypes, and all the data have been processed using identical approaches. Our analysis of microbiome composition shows that we can reduce the potential artifacts introduced by technical differences in generating microbiota data. We are now in the process of benchmarking the association tests and performing meta-analyses of genome-wide associations. All pipeline and summary statistics results will be shared using public data repositories. Conclusion We present the largest consortium to date devoted to microbiota-GWAS. We have adapted our analytical pipelines to suit multi-cohort analyses and expect to gain insight into host-microbiota cross-talk at the genome-wide level. And, as an open consortium, we invite more cohorts to join us (by contacting one of the corresponding authors) and to follow the analytical pipeline we have developed

The Genome Sequence of the Leaf-Cutter Ant Atta cephalotes Reveals Insights into Its Obligate Symbiotic Lifestyle

Leaf-cutter ants are one of the most important herbivorous insects in the Neotropics, harvesting vast quantities of fresh leaf material. The ants use leaves to cultivate a fungus that serves as the colony's primary food source. This obligate ant-fungus mutualism is one of the few occurrences of farming by non-humans and likely facilitated the formation of their massive colonies. Mature leaf-cutter ant colonies contain millions of workers ranging in size from small garden tenders to large soldiers, resulting in one of the most complex polymorphic caste systems within ants. To begin uncovering the genomic underpinnings of this system, we sequenced the genome of Atta cephalotes using 454 pyrosequencing. One prediction from this ant's lifestyle is that it has undergone genetic modifications that reflect its obligate dependence on the fungus for nutrients. Analysis of this genome sequence is consistent with this hypothesis, as we find evidence for reductions in genes related to nutrient acquisition. These include extensive reductions in serine proteases (which are likely unnecessary because proteolysis is not a primary mechanism used to process nutrients obtained from the fungus), a loss of genes involved in arginine biosynthesis (suggesting that this amino acid is obtained from the fungus), and the absence of a hexamerin (which sequesters amino acids during larval development in other insects). Following recent reports of genome sequences from other insects that engage in symbioses with beneficial microbes, the A. cephalotes genome provides new insights into the symbiotic lifestyle of this ant and advances our understanding of host–microbe symbioses