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2.
J Vasc Interv Radiol ; 2024 Jun 19.
Article in English | MEDLINE | ID: mdl-38906245

ABSTRACT

PURPOSE: To estimate the risk of hepatobiliary infection, including endoTIPSitis, liver abscesses, and cholangitis, after transjugular intrahepatic portosystemic shunt (TIPS) creation in patients with prior biliary intervention. MATERIALS AND METHODS: This multi-institution, retrospective study identified 76 patients (n = 48 males; mean age, 54.9 years; mean Model for End-stage Liver Disease [MELD] score, 13.2; n = 45 for ascites and n = 23 for varices; n = 31 with prior liver transplantation) among 2,130 (3.6%) undergoing TIPS creation who had prior biliary intervention (n = 19 bilioenteric anastomoses, n = 35 sphincterotomies, n = 28 internal plastic stent placements, n = 4 internal metal stent placements, and n = 6 percutaneous biliary drain placements). The baseline risk of post-TIPS creation hepatobiliary infection was estimated from a control group of 1,202 TIPS creation procedures in patients without prior biliary intervention. RESULTS: Eleven (14.5%) of 76 patients developed hepatobiliary infection after TIPS creation, including 7 with endoTIPSitis, 4 with hepatic abscesses, and 2 with cholangitis. The 30-day risk of infection was 10.9% (95% confidence interval [CI], 3.5%-17.8%), significantly higher than the 0.4% risk (95% CI, 0.1%-0.8%) observed in patients without prior biliary intervention (hazard ratio [HR], 25.56; 95% CI, 8.36-78.13; P < .001). All types of biliary intervention were associated with increased risk of infection, with bilioenteric anastomoses conferring the highest risk. Paradoxically, among patients with prior biliary intervention, use of postprocedural antibiotic prophylaxis was associated with an increased infection risk (HR, 19.85; 95% CI, 2.44-161.50; P = .005). Microbial culture data showed high rates of Enterococcus, Klebsiella, and Candida species. CONCLUSIONS: Prior biliary intervention was associated with a 10.9% risk of hepatobiliary infection, including endoTIPSitis, liver abscess, and cholangitis, within 30 days after TIPS creation.

3.
J Am Geriatr Soc ; 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38863338

ABSTRACT

BACKGROUND: Relationships of midlife inflammation with late-life mobility and influences of chronic health conditions, race, and social determinants of health (SDoH) on these relationships are poorly understood. METHODS: Among 4758 community-dwelling participants (41% men, 20% Black), high-sensitivity C-reactive protein (hsCRP) was measured over 20+ years: in midlife at study visit 2 (V2: 1990-1992, 47-68 years); at V4 (1996-1998, 53-74 years); and with concurrent late-life 4-m gait speed at V5 (2011-2013, 67-88 years, mean 75 years). SDoH measures included race, the national-rank area deprivation index, education, and income. We examined associations of late-life gait speed with midlife hsCRP (V2 continuous and clinically high ≥3 mg/L), with 20-year hsCRP history from midlife (V2-V5 average continuous hsCRP and clinically high ≥3 mg/L) and with inflammation accumulation (visits and years with high hsCRP). Regression models adjusted for demographic, cardiovascular, and SDoH measures; effect modification by the presence of other common chronic conditions (obesity, diabetes, hypertension) and race were examined, with and without accounting for SDoH. RESULTS: High midlife hsCRP was associated with slower late-life gait speed, even among those without chronic conditions in midlife: -4.6 cm/s (95% CI: -6.4, -2.8). Importantly, sustained high hsCRP was associated with a 20-year slowing of -10.0 cm/s (-14.9, -5.1) among those who never experienced obesity, diabetes, or hypertension over the 20-year period. Associations were similar between Black participants, -3.8 cm/s (-6.9, -0.7) and White participants -3.3 (-4.5, -2.2) per interquartile range of midlife hsCRP; effect modifications by chronic conditions and race were unsupported throughout. Results were robust to accounting for SDoH or otherwise; however, worse SDoH was associated with higher inflammation and slower gait speed in both Black and White participants. CONCLUSIONS: Inflammation in midlife may contribute to clinically meaningful late-life slowing of gait speed, even among otherwise healthy-appearing adults and regardless of race and socioeconomic disadvantage. Regular monitoring and interventions for inflammation may be warranted from midlife.

4.
bioRxiv ; 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38853870

ABSTRACT

While circadian rhythm disruption may promote neurodegenerative disease, how aging and neurodegenerative pathology impact circadian gene expression patterns in different brain cell types is unknown. Here, we used translating ribosome affinity purification methods to define the circadian translatomes of astrocytes, microglia, and bulk cerebral cortex, in healthy mouse brain and in the settings of amyloid-beta plaque pathology or aging. Our data reveal that glial circadian translatomes are highly cell type-specific and exhibit profound, context-dependent reprogramming of rhythmic transcripts in response to amyloid pathology or aging. Transcripts involved in glial activation, immunometabolism, and proteostasis, as well as nearly half of all Alzheimer Disease (AD)-associated risk genes, displayed circadian oscillations, many of which were altered by pathology. Amyloid-related differential gene expression was also dependent on time of day. Thus, circadian rhythms in gene expression are cell- and context dependent and provide important insights into glial gene regulation in health, AD, and aging.

5.
6.
JCI Insight ; 9(9)2024 May 08.
Article in English | MEDLINE | ID: mdl-38716727

ABSTRACT

Pancreatic ductal adenocarcinoma (PDA) is a lethal cancer characterized by a poor outcome and an increasing incidence. A significant majority (>80%) of newly diagnosed cases are deemed unresectable, leaving chemotherapy as the sole viable option, though with only moderate success. This necessitates the identification of improved therapeutic options for PDA. We hypothesized that there are temporal variations in cancer-relevant processes within PDA tumors, offering insights into the optimal timing of drug administration - a concept termed chronotherapy. In this study, we explored the presence of the circadian transcriptome in PDA using patient-derived organoids and validated these findings by comparing PDA data from The Cancer Genome Atlas with noncancerous healthy pancreas data from GTEx. Several PDA-associated pathways (cell cycle, stress response, Rho GTPase signaling) and cancer driver hub genes (EGFR and JUN) exhibited a cancer-specific rhythmic pattern intricately linked to the circadian clock. Through the integration of multiple functional measurements for rhythmic cancer driver genes, we identified top chronotherapy targets and validated key findings in molecularly divergent pancreatic cancer cell lines. Testing the chemotherapeutic efficacy of clinically relevant drugs further revealed temporal variations that correlated with drug-target cycling. Collectively, our study unravels the PDA circadian transcriptome and highlights a potential approach for optimizing chrono-chemotherapeutic efficacy.


Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Transcriptome , Humans , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/pathology , Carcinoma, Pancreatic Ductal/genetics , Carcinoma, Pancreatic Ductal/drug therapy , Carcinoma, Pancreatic Ductal/pathology , Cell Line, Tumor , Gene Expression Regulation, Neoplastic/drug effects , Circadian Rhythm/genetics , Organoids/drug effects , Circadian Clocks/genetics , Circadian Clocks/drug effects , Antineoplastic Agents/therapeutic use , Antineoplastic Agents/pharmacology , Adenocarcinoma/genetics , Adenocarcinoma/drug therapy , Adenocarcinoma/pathology , Chronotherapy/methods
7.
J Vasc Interv Radiol ; 2024 Apr 27.
Article in English | MEDLINE | ID: mdl-38685470

ABSTRACT

Genicular artery embolization (GAE) is an emerging, minimally invasive therapy to address the global burden of knee osteoarthritis (OA) and the unmet needs for medically refractory disease. Although total knee arthroplasty has been a standard intervention for severe cases, GAE is developing into a promising alternative, particularly for patients ineligible for or unwilling to undergo surgery. GAE targets the inflammatory cascade underlying OA pathophysiology by arresting neoangiogenesis and preventing pathological neoinnervation, offering potential pain relief. Although early studies have established safety and short-term effectiveness, ensuing studies are needed to validate long-term safety, durability, and comparative effectiveness and to optimize patient selection, embolic agent selection, and administration techniques. Standardized reporting guidelines are therefore essential to enhance transparency and reproducibility across clinical trials, facilitating data aggregation and comparison. This Society of Interventional Radiology (SIR)-endorsed reporting standards consensus document provides a framework to harmonize future research efforts and to improve the interpretation of outcomes.

8.
JAMA Cardiol ; 9(6): 497-506, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38598228

ABSTRACT

Importance: Clonal hematopoiesis of indeterminate potential (CHIP) may contribute to the risk of atrial fibrillation (AF) through its association with inflammation and cardiac remodeling. Objective: To determine whether CHIP was associated with AF, inflammatory and cardiac biomarkers, and cardiac structural changes. Design, Setting, and Participants: This was a population-based, prospective cohort study in participants of the Atherosclerosis Risk in Communities (ARIC) study and UK Biobank (UKB) cohort. Samples were collected and echocardiography was performed from 2011 to 2013 in the ARIC cohort, and samples were collected from 2006 to 2010 in the UKB cohort. Included in this study were adults without hematologic malignancies, mitral valve stenosis, or previous mitral valve procedure from both the ARIC and UKB cohorts; additionally, participants without hypertrophic cardiomyopathy and congenital heart disease from the UKB cohort were also included. Data analysis was completed in 2023. Exposures: CHIP (variant allele frequency [VAF] ≥2%), common gene-specific CHIP subtypes (DNMT3A, TET2, ASXL1), large CHIP (VAF ≥10%), inflammatory and cardiac biomarkers (high-sensitivity C-reactive protein, interleukin 6 [IL-6], IL-18, high-sensitivity troponin T [hs-TnT] and hs-TnI, N-terminal pro-B-type natriuretic peptide), and echocardiographic indices. Main Outcome Measure: Incident AF. Results: A total of 199 982 adults were included in this study. In ARIC participants (4131 [2.1%]; mean [SD] age, 76 [5] years; 2449 female [59%]; 1682 male [41%]; 935 Black [23%] and 3196 White [77%]), 1019 had any CHIP (24.7%), and 478 had large CHIP (11.6%). In UKB participants (195 851 [97.9%]; mean [SD] age, 56 [8] years; 108 370 female [55%]; 87 481 male [45%]; 3154 Black [2%], 183 747 White [94%], and 7971 other race [4%]), 11 328 had any CHIP (5.8%), and 5189 had large CHIP (2.6%). ARIC participants were followed up for a median (IQR) period of 7.0 (5.3-7.7) years, and UKB participants were followed up for a median (IQR) period of 12.2 (11.3-13.0) years. Meta-analyzed hazard ratios for AF were 1.12 (95% CI, 1.01-1.25; P = .04) for participants with vs without large CHIP, 1.29 (95% CI, 1.05-1.59; P = .02) for those with vs without large TET2 CHIP (seen in 1340 of 197 209 [0.67%]), and 1.45 (95% CI, 1.02-2.07; P = .04) for those with vs without large ASXL1 CHIP (seen in 314 of 197 209 [0.16%]). Large TET2 CHIP was associated with higher IL-6 levels. Additionally, large ASXL1 was associated with higher hs-TnT level and increased left ventricular mass index. Conclusions and Relevance: Large TET2 and ASXL1, but not DNMT3A, CHIP was associated with higher IL-6 level, indices of cardiac remodeling, and increased risk for AF. Future research is needed to elaborate on the mechanisms driving the associations and to investigate potential interventions to reduce the risk.


Subject(s)
Atrial Fibrillation , Clonal Hematopoiesis , DNA-Binding Proteins , Dioxygenases , Proto-Oncogene Proteins , Repressor Proteins , Humans , Female , Male , Atrial Fibrillation/genetics , Clonal Hematopoiesis/genetics , Repressor Proteins/genetics , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Middle Aged , Proto-Oncogene Proteins/genetics , Prospective Studies , Aged , DNA Methyltransferase 3A , DNA (Cytosine-5-)-Methyltransferases/genetics , Biomarkers/blood , Biomarkers/metabolism , C-Reactive Protein/metabolism , C-Reactive Protein/genetics , Interleukin-6/genetics , Interleukin-6/metabolism , Troponin T/genetics , Troponin T/blood , Troponin T/metabolism , Echocardiography , United Kingdom/epidemiology
9.
J Am Coll Cardiol ; 83(16): 1511-1525, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38631771

ABSTRACT

BACKGROUND: Lipoprotein(a) (Lp[a]) is a causal genetic risk factor for atherosclerotic cardiovascular disease (ASCVD). There are limited long-term follow-up data from large U.S. population cohorts. OBJECTIVES: This study examined the relationship of Lp(a) with ASCVD outcomes in a large, pooled, multi-ethnic U.S. METHODS: The study included data on Lp(a) and ASCVD outcomes from 5 U.S. PROSPECTIVE STUDIES: MESA (Multi-Ethnic Study of Atherosclerosis), CARDIA (Coronary Artery Risk Development in Young Adults), JHS (Jackson Heart Study), FHS-OS (Framingham Heart Study-Offspring), and ARIC (Atherosclerosis Risk In Communities). Lp(a) levels were classified on the basis of cohort-specific percentiles. Multivariable Cox regression related Lp(a) with composite incident ASCVD events by risk group and diabetes status. RESULTS: The study included 27,756 persons without previous ASCVD who were aged 20 to 79 years, including 55.0% women, 35.6% Black participants, and 7.6% patients with diabetes, with mean follow-up of 21.1 years. Compared with Lp(a) levels <50th percentile, Lp(a) levels in the 50th to <75th, 75th to <90th, and ≥90th percentiles had adjusted HRs of 1.06 (95% CI: 0.99-1.14), 1.18 (95% CI: 1.09-1.28), and 1.46 (95% CI: 1.33-1.59), respectively for ASCVD events. Elevated Lp(a) predicted incident ASCVD events similarly by risk group, sex, and race or ethnic groups, but more strongly in patients with vs without diabetes (interaction P = 0.0056), with HRs for Lp(a) levels ≥90th percentile of 1.92 (95% CI: 1.50-2.45) and 1.41 (95% CI: 1.28-1.55), respectively. Lp(a) also individually predicted myocardial infarction, revascularization, stroke, and coronary heart disease death, but not total mortality. CONCLUSIONS: The study shows, in a large U.S. pooled cohort, that higher Lp(a) levels are associated with an increased ASCVD risk, including in patients with diabetes.


Subject(s)
Atherosclerosis , Cardiovascular Diseases , Diabetes Mellitus , Humans , Female , Male , Prospective Studies , Cardiovascular Diseases/epidemiology , Risk Factors , Lipoprotein(a) , Atherosclerosis/epidemiology , Heart Disease Risk Factors , Risk Assessment
10.
ACS Catal ; 14(7): 4999-5005, 2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38601777

ABSTRACT

Isolated platinum(II) ions anchored at acid sites in the pores of zeolite HZSM-5, initially introduced by aqueous ion exchange, were reduced to form platinum nanoparticles that are stably dispersed with a narrow size distribution (1.3 ± 0.4 nm in average diameter). The nanoparticles were confined in reservoirs within the porous zeolite particles, as shown by electron beam tomography and the shape-selective catalysis of alkene hydrogenation. When the nanoparticles were oxidatively fragmented in dry air at elevated temperature, platinum returned to its initial in-pore atomically dispersed state with a charge of +2, as shown previously by X-ray absorption spectroscopy. The results determine the conditions under which platinum is retained within the pores of HZSM-5 particles during redox cycles that are characteristic of the reductive conditions of catalyst operation and the oxidative conditions of catalyst regeneration.

11.
J Am Chem Soc ; 146(14): 10060-10072, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38551239

ABSTRACT

The reduction of CO2 is known to promote increased alkene yields from alkane dehydrogenations when the reactions are cocatalyzed. The mechanism of this promotion is not understood in the context of catalyst active-site environments because CO2 is amphoteric, and even general aspects of the chemistry, including the significance of competing side reactions, differ significantly across catalysts. Atomically dispersed chromium cations stabilized in highly siliceous MFI zeolite are shown here to enable the study of the role of parallel CO2 reduction during ethylene-selective ethane dehydrogenation. Based on infrared spectroscopy and X-ray absorption spectroscopy data interpreted through calculations using density functional theory (DFT), the synthesized catalyst contains atomically dispersed Cr cations stabilized by silanol nests in micropores. Reactor studies show that cofeeding CO2 increases stable ethylene-selective ethane dehydrogenation rates over a wide range of partial pressures. Operando X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) spectra indicate that during reaction at 650 °C the Cr cations maintain a nominal 2+ charge and a total Cr-O coordination number of approximately 2. However, CO2 reduction induces a change, correlated with the CO2 partial pressure, in the population of two distinct Cr-O scattering paths. This indicates that the promotional effect of parallel CO2 reduction can be attributed to a subtle change in Cr-O bond lengths in the local coordination environment of the active site. These insights are made possible by simultaneously fitting multiple EXAFS spectra recorded in different reaction conditions; this novel procedure is expected to be generally applicable for interpreting operando catalysis EXAFS data.

12.
J Vasc Interv Radiol ; 35(5): 659-663, 2024 May.
Article in English | MEDLINE | ID: mdl-38355039

ABSTRACT

This retrospective case series assessed the early effectiveness of combined spontaneous portosystemic shunt (SPSS) embolization and preemptive transjugular intrahepatic portosystemic shunt (TIPS) creation for alleviation of medically refractory hepatic encephalopathy (HE) and prevention of portal hypertension complications in patients with liver cirrhosis. Eight patients with liver cirrhosis (5 men and 3 women; mean age, 61 years [SD ± 10]) and HE (overt [West-Haven Grade 2-4], n = 7; covert [West-Haven Grade 1], n = 1) refractory to lactulose and rifaximin therapy who underwent concurrent or staged SPSS embolization and TIPS creation between 2018 and 2022 were included in this study. The primary outcomes were 3-month improvement in HE and postprocedural HE-related hospitalizations. HE improvement was achieved in 7 (87.5%) of 8 cases. Among all patients, there was 1 HE-related hospitalization within 90 days that responded to repeat embolization with no further admissions. No patients developed new ascites, variceal hemorrhage, or other portal hypertension complications within 3 months.


Subject(s)
Embolization, Therapeutic , Hepatic Encephalopathy , Liver Cirrhosis , Portasystemic Shunt, Transjugular Intrahepatic , Humans , Hepatic Encephalopathy/etiology , Hepatic Encephalopathy/therapy , Middle Aged , Male , Embolization, Therapeutic/adverse effects , Female , Portasystemic Shunt, Transjugular Intrahepatic/adverse effects , Retrospective Studies , Treatment Outcome , Aged , Liver Cirrhosis/complications , Time Factors , Hypertension, Portal/physiopathology , Hypertension, Portal/etiology , Hypertension, Portal/therapy , Portal Pressure
13.
J Vasc Interv Radiol ; 35(5): 731-743.e36, 2024 May.
Article in English | MEDLINE | ID: mdl-38320622

ABSTRACT

PURPOSE: To correlate epigenetic patterns with ethnoracial status and locoregional therapy (LRT) response in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: DNA and RNA were extracted from 47 distinct formalin-fixed paraffin-embedded tumor samples from 42 patients with HCC (n = 14 Black, n = 19 White, n = 9 Hispanic). LRT response was determined using computed tomography (CT) or magnetic resonance (MR) imaging 3 months posttreatment of 35 tumors (n = 22 complete response, n = 13 retreatment candidates). RNA expression and DNA methylation were used to stratify patients by ethnoracial status and treatment response using partial least-squares discriminant analysis (PLS-DA). Results were validated using hierarchical clustering. Ingenuity pathway analysis was performed to identify upstream regulators and pathways. RESULTS: PLS-DA identified 100 genes and 12 methylated regions that differentiated tumors from Black from White/Hispanic patients. Hierarchical clustering clustered samples with the top 16 genes or the top 5 methylation regions. Dysregulated pathways included adrenomedullin pathway (P = .030), EIF2 signaling (P = .007), and several metabolic pathways. AGTR1 (log2fold = 1.59) and GSTM3 (log2fold = 2.53) represented potential differentially expressed therapeutic targets. PLS-DA identified 100 genes and 150 methylation regions that differentiated between complete responders and retreatment candidates. Hierarchical clustering clustered samples with the top 30 genes or the top 13 methylation regions. Dysregulated pathways included metabolic and DNA repair-related pathways. ASAP2 (log2fold = 0.29) and RAD50 (log2fold = 0.22) represented potential differentially expressed therapeutic targets. CONCLUSIONS: Variation in gene expression and DNA methylation patterns in patients with HCC corresponded to ethnoracial status and LRT response. These initial results suggest tumor profiling has the potential to close ethnoracial disparities and improve treatment stratification.


Subject(s)
Carcinoma, Hepatocellular , DNA Methylation , Epigenesis, Genetic , Liver Neoplasms , Adult , Aged , Female , Humans , Male , Middle Aged , Biomarkers, Tumor/genetics , Black or African American/genetics , Carcinoma, Hepatocellular/genetics , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Liver Neoplasms/genetics , Magnetic Resonance Imaging , Retrospective Studies , Tomography, X-Ray Computed , Treatment Outcome , White , Hispanic or Latino
14.
Front Health Serv Manage ; 40(3): 17-23, 2024.
Article in English | MEDLINE | ID: mdl-38386462

ABSTRACT

It comes as no surprise that healthcare leaders today face unprecedented challenges. Some are immediate. Others are long-term. Many are interrelated. All are complex. None of them are small, as they include financial sustainability, mission, quality and patient safety, rapidly advancing technology, changing consumer expectations, new market entrants, healthcare inequities, and more regulation. One challenge, though, tops that list: workforce shortages. Although many individuals continue to be drawn to healthcare, the numbers are insufficient to meet increasing demand. Transforming care models will be crucial in meeting the needs of communities. The development of core competencies in driving transformation-embracing innovation and technology, creating a shared vision, and engaging teams in this process-is essential in leading this transformation.


Subject(s)
Delivery of Health Care , Leadership , Humans , Workforce , Health Facilities , Technology
15.
Article in English | MEDLINE | ID: mdl-38404646

ABSTRACT

Background: Nasal tracheal intubation (TI) represents a minority of all TI in the pediatric intensive care unit (PICU). The risks and benefits of nasal TI are not well quantified. As such, safety and descriptive data regarding this practice are warranted. Methods: We evaluated the association between TI route and safety outcomes in a prospectively collected quality improvement database (National Emergency Airway Registry for Children: NEAR4KIDS) from 2013 to 2020. The primary outcome was severe desaturation (SpO2 > 20% from baseline) and/or severe adverse TI-associated events (TIAEs), using NEAR4KIDS definitions. To balance patient, provider, and practice covariates, we utilized propensity score (PS) matching to compare the outcomes of nasal vs. oral TI. Results: A total of 22,741 TIs [nasal 870 (3.8%), oral 21,871 (96.2%)] were reported from 60 PICUs. Infants were represented in higher proportion in the nasal TI than the oral TI (75.9%, vs 46.2%), as well as children with cardiac conditions (46.9% vs. 14.4%), both p < 0.001. Severe desaturation or severe TIAE occurred in 23.7% of nasal and 22.5% of oral TI (non-adjusted p = 0.408). With PS matching, the prevalence of severe desaturation and or severe adverse TIAEs was 23.6% of nasal vs. 19.8% of oral TI (absolute difference 3.8%, 95% confidence interval (CI): - 0.07, 7.7%), p = 0.055. First attempt success rate was 72.1% of nasal TI versus 69.2% of oral TI, p = 0.072. With PS matching, the success rate was not different between two groups (nasal 72.2% vs. oral 71.5%, p = 0.759). Conclusion: In this large international prospective cohort study, the risk of severe peri-intubation complications was not significantly higher. Nasal TI is used in a minority of TI in PICUs, with substantial differences in patient, provider, and practice compared to oral TI.A prospective multicenter trial may be warranted to address the potential selection bias and to confirm the safety of nasal TI.

16.
J Am Chem Soc ; 146(6): 3773-3784, 2024 Feb 14.
Article in English | MEDLINE | ID: mdl-38301281

ABSTRACT

A longstanding challenge in catalysis by noble metals has been to understand the origin of enhancements of rates of hydrogen transfer that result from the bonding of oxygen near metal sites. We investigated structurally well-defined catalysts consisting of supported tetrairidium carbonyl clusters with single-atom (apical iridium) catalytic sites for ethylene hydrogenation. Reaction of the clusters with ethylene and H2 followed by O2 led to the onset of catalytic activity as a terminal CO ligand at each apical Ir atom was removed and bridging dioxygen ligands replaced CO ligands at neighboring (basal-plane) sites. The presence of the dioxygen ligands caused a 6-fold increase in the catalytic reaction rate, which is explained by the electron-withdrawing capability induced by the bridging dioxygen ligands, consistent with the inference that reductive elimination is rate-determining. Electronic-structure calculations demonstrate an additional role of the dioxygen ligands, changing the mechanism of hydrogen transfer from one involving equatorial hydride ligands to that involving bridging hydride ligands. This mechanism is made evident by an inverse kinetic isotope effect observed in ethylene hydrogenation reactions with H2 and, alternatively, with D2 on the cluster incorporating the dioxygen ligands and is a consequence of quasi-equilibrated hydrogen transfer in this catalyst. The same mechanism accounts for rate enhancements induced by the bridging dioxygen ligands for the catalytic reaction of H2 with D2 to give HD. We posit that the mechanism involving bridging hydride ligands facilitated by oxygen ligands remote from the catalytic site may have some generality in catalysis by oxide-supported noble metals.

17.
Proc Natl Acad Sci U S A ; 121(7): e2311854121, 2024 Feb 13.
Article in English | MEDLINE | ID: mdl-38319971

ABSTRACT

Studies in shift workers and model organisms link circadian disruption to breast cancer. However, molecular circadian rhythms in noncancerous and cancerous human breast tissues and their clinical relevance are largely unknown. We reconstructed rhythms informatically, integrating locally collected, time-stamped biopsies with public datasets. For noncancerous breast tissue, inflammatory, epithelial-mesenchymal transition (EMT), and estrogen responsiveness pathways show circadian modulation. Among tumors, clock correlation analysis demonstrates subtype-specific changes in circadian organization. Luminal A organoids and informatic ordering of luminal A samples exhibit continued, albeit dampened and reprogrammed rhythms. However, CYCLOPS magnitude, a measure of global rhythm strength, varied widely among luminal A samples. Cycling of EMT pathway genes was markedly increased in high-magnitude luminal A tumors. Surprisingly, patients with high-magnitude tumors had reduced 5-y survival. Correspondingly, 3D luminal A cultures show reduced invasion following molecular clock disruption. This study links subtype-specific circadian disruption in breast cancer to EMT, metastatic potential, and prognosis.


Subject(s)
Breast Neoplasms , Circadian Clocks , Humans , Female , Breast Neoplasms/pathology , Circadian Clocks/genetics , Circadian Rhythm , Estrogens , Prognosis
18.
J Am Coll Cardiol ; 83(5): 577-591, 2024 02 06.
Article in English | MEDLINE | ID: mdl-38296402

ABSTRACT

BACKGROUND: Limited data exist regarding risk factors for aortic stenosis (AS). The plasma proteome is a promising phenotype for discovery of novel biomarkers and potentially causative mechanisms. OBJECTIVES: The aim of this study was to discover novel biomarkers with potentially causal associations with AS. METHODS: We measured 4,877 plasma proteins (SomaScan aptamer-affinity assay) among ARIC (Atherosclerosis Risk In Communities) study participants in mid-life (visit 3 [V3]; n = 11,430; age 60 ± 6 years) and in late-life (V5; n = 4,899; age 76 ± 5 years). We identified proteins cross-sectionally associated with aortic valve (AV) peak velocity (AVmax) and dimensionless index by echocardiography at V5 and with incident AV-related hospitalization after V3 with the use of multivariable linear and Cox proportional hazard regression. We assessed associations of candidate proteins with changes in AVmax over 6 years and with AV calcification with the use of cardiac computed tomography, replicated analysis in an independent sample, performed Mendelian randomization, and evaluated gene expression in explanted human AV tissue. RESULTS: Fifty-two proteins cross-sectionally were associated with AVmax and dimensionless index at V5 and with risk of incident AV-related hospitalization after V3. Among 3,413 participants in the Cardiovascular Health Study, 6 of those proteins were significantly associated with adjudicated moderate or severe AS, including matrix metalloproteinase 12 (MMP12), complement C1q tumor necrosis factor-related protein 1 (C1QTNF1), and growth differentiation factor-15. MMP12 was also associated with greater increase in AVmax over 6 years, greater degree of AV calcification, and greater expression in calcific compared with normal or fibrotic AV tissue. C1QTNF1 had consistent potential causal effects on both AS and AVmax according to Mendelian randomization analysis. CONCLUSIONS: These findings identify MMP12 as a potential novel circulating biomarker of AS risk and C1QTNF1 as a new putative target to prevent AS progression.


Subject(s)
Aortic Valve Stenosis , Aortic Valve/pathology , Calcinosis , Proteomics , Humans , Middle Aged , Aged , Aged, 80 and over , Matrix Metalloproteinase 12 , Risk Factors , Aortic Valve/diagnostic imaging , Biomarkers
19.
ESC Heart Fail ; 11(2): 1086-1096, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38258344

ABSTRACT

AIMS: Heart failure (HF) has shared genetic architecture with its risk factors: atrial fibrillation (AF), body mass index (BMI), coronary heart disease (CHD), systolic blood pressure (SBP), and type 2 diabetes (T2D). We aim to assess the association and risk prediction performance of risk-factor polygenic risk scores (PRSs) for incident HF and its subtypes in bi-racial populations. METHODS AND RESULTS: Five PRSs were constructed for AF, BMI, CHD, SBP, and T2D in White participants of the Atherosclerosis Risk in Communities (ARIC) study. The associations between PRSs and incident HF and its subtypes were assessed using Cox models, and the risk prediction performance of PRSs was assessed using C statistics. Replication was performed in the ARIC study Black and Cardiovascular Health Study (CHS) White participants. In 8624 ARIC study Whites, 1922 (31% cumulative incidence) HF cases developed over 30 years of follow-up. PRSs of AF, BMI, and CHD were associated with incident HF (P < 0.001), where PRSAF showed the strongest association [hazard ratio (HR): 1.47, 95% confidence interval (CI): 1.41-1.53]. Only the addition of PRSAF to the ARIC study HF risk equation improved C statistics for 10 year risk prediction from 0.812 to 0.829 (∆C: 0.017, 95% CI: 0.009-0.026). The PRSAF was associated with both incident HF with reduced ejection fraction (HR: 1.43, 95% CI: 1.27-1.60) and incident HF with preserved ejection fraction (HR: 1.46, 95% CI: 1.33-1.62). The associations between PRSAF and incident HF and its subtypes, as well as the improved risk prediction, were replicated in the ARIC study Blacks and the CHS Whites (P < 0.050). Protein analyses revealed that N-terminal pro-brain natriuretic peptide and other 98 proteins were associated with PRSAF. CONCLUSIONS: The PRSAF was associated with incident HF and its subtypes and had significant incremental value over an established HF risk prediction equation.


Subject(s)
Atherosclerosis , Atrial Fibrillation , Coronary Disease , Diabetes Mellitus, Type 2 , Heart Failure , Humans , Atrial Fibrillation/epidemiology , Genetic Risk Score , Diabetes Mellitus, Type 2/complications , Risk Factors , Atherosclerosis/complications , Coronary Disease/complications , Coronary Disease/epidemiology
20.
J Am Coll Cardiol ; 83(5): 562-573, 2024 02 06.
Article in English | MEDLINE | ID: mdl-38296400

ABSTRACT

BACKGROUND: American College of Cardiology/American Heart Association guidelines recommend distinct risk classification systems for primary and secondary cardiovascular disease prevention. However, both systems rely on similar predictors (eg, age and diabetes), indicating the possibility of a universal risk prediction approach for major adverse cardiovascular events (MACEs). OBJECTIVES: The authors examined the performance of predictors in persons with and without atherosclerotic cardiovascular disease (ASCVD) and developed and validated a universal risk prediction model. METHODS: Among 9,138 ARIC (Atherosclerosis Risk In Communities) participants with (n = 609) and without (n = 8,529) ASCVD at baseline (1996-1998), we examined established predictors in the risk classification systems and other predictors, such as body mass index and cardiac biomarkers (troponin and natriuretic peptide), using Cox models with MACEs (myocardial infarction, stroke, and heart failure). We also evaluated model performance. RESULTS: Over a follow-up of approximately 20 years, there were 3,209 MACEs (2,797 for no prior ASCVD). Most predictors showed similar associations with MACE regardless of baseline ASCVD status. A universal risk prediction model with the predictors (eg, established predictors, cardiac biomarkers) identified by least absolute shrinkage and selection operator regression and bootstrapping showed good discrimination for both groups (c-statistics of 0.747 and 0.691, respectively), and risk classification and showed excellent calibration, irrespective of ASCVD status. This universal prediction approach identified individuals without ASCVD who had a higher risk than some individuals with ASCVD and was validated externally in 5,322 participants in the MESA (Multi-Ethnic Study of Atherosclerosis). CONCLUSIONS: A universal risk prediction approach performed well in persons with and without ASCVD. This approach could facilitate the transition from primary to secondary prevention by streamlining risk classification and discussion between clinicians and patients.


Subject(s)
Atherosclerosis , Cardiovascular Diseases , Myocardial Infarction , United States/epidemiology , Humans , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/epidemiology , Risk Assessment , Atherosclerosis/diagnosis , Atherosclerosis/epidemiology , Biomarkers , Risk Factors
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