Computational Insights into the Mechanism of Nitric Oxide Generation from S-Nitrosoglutathione Catalyzed by a Copper Metal-Organic Framework.

The controlled generation of nitric oxide (NO) from endogenous sources, such as S-nitrosoglutathione (GSNO), has significant implications for biomedical implants due to the vasodilatory and other beneficial properties of NO. The water-stable metal-organic framework (MOF) Cu-1,3,5-tris[1H-1,2,3-triazol-5-yl]benzene has been shown to catalyze the production of NO and glutathione disulfide (GSSG) from GSNO in aqueous solution as well as in blood. Previous experimental work provided kinetic data for the catalysis of the 2GSNO → 2NO + GSSG reaction, leading to various proposed mechanisms. Herein, this catalytic process is examined using density functional theory. Minimal functional models of the Cu-MOF cluster and glutathione moieties are established, and three distinct catalytic mechanisms are explored. The most thermodynamically favorable mechanism studied is consistent with prior experimental findings. This mechanism involves coordination of GSNO to copper via sulfur rather than nitrogen and requires a reductive elimination that produces a Cu(I) intermediate, implicating a redox-active copper site. The experimentally observed inhibition of reactivity at high pH values is explained in terms of deprotonation of a triazole linker, which decreases the structural stability of the Cu(I) intermediate. These fundamental mechanistic insights may be generally applicable to other MOF catalysts for NO generation.

Preoperative Evaluation of Thyroid Cancer: A Review of Current Best Practices.

OBJECTIVE: The incidence of thyroid cancer has significantly increased in recent decades. Although most thyroid cancers are small and carry an excellent prognosis, a subset of patients present with advanced thyroid cancer, which is associated with increased rates of morbidity and mortality. The management of thyroid cancer requires a thoughtful individualized approach to optimize oncologic outcomes and minimize morbidity associated with treatment. Because endocrinologists usually play a key role in the initial diagnosis and evaluation of thyroid cancers, a thorough understanding of the critical components of the preoperative evaluation facilitates the development of a timely and comprehensive management plan. The following review outlines considerations in the preoperative evaluation of patients with thyroid cancer. METHODS: A clinical review based on current literature was generated by a multidisciplinary author panel. RESULTS: A review of considerations in the preoperative evaluation of thyroid cancer is provided. The topic areas include initial clinical evaluation, imaging modalities, cytologic evaluation, and the evolving role of mutational testing. Special considerations in the management of advanced thyroid cancer are discussed. CONCLUSION: Thorough and thoughtful preoperative evaluation is critical for formulating an appropriate treatment strategy in the management of thyroid cancer.

Specialized Metabolite-Mediated Predation Defense in the Marine Actinobacterium Salinispora.

The obligate marine actinobacterial genus Salinispora has become a model organism for natural product discovery, yet little is known about the ecological functions of the compounds produced by this taxon. The aims of this study were to assess the effects of live cultures and culture extracts from two Salinispora species on invertebrate predators. In choice-based feeding experiments using the bacterivorous nematode Caenorhabditis elegans, live cultures of both Salinispora species were less preferred than Escherichia coli. When given a choice between the two species, C. elegans preferred S. areniolca over S. tropica. Culture extracts from S. tropica deterred C. elegans, while those from S. arenicola did not, suggesting that compounds produced by S. tropica account for the feeding deterrence. Bioactivity-guided isolation linked compounds in the lomaiviticin series to the deterrent activity. Additional assays using the marine polychaete Ophryotrocha siberti and marine nematodes further support the deterrent activity of S. tropica against potential predators. These results provide evidence that Salinispora natural products function as a defense against predation and that the strategies of predation defense differ between closely related species. IMPORTANCE Bacteria inhabiting marine sediments are subject to predation by bacterivorous eukaryotes. Here, we test the hypothesis that sediment-derived bacteria in the genus Salinispora produce biologically active natural products that function as a defense against predation. The results reveal that cultures and culture extracts of S. tropica deter feeding by Caenorhabditis elegans and negatively affect the habitat preference of a marine annelid (Ophryotrocha siberti). These activities were linked to the lomaiviticins, a series of cytotoxic compounds produced by S. tropica. Microbial natural products that function as a defense against predation represent a poorly understood trait that can influence community structure in marine sediments.

Primary high-grade non-anaplastic thyroid carcinoma: a retrospective study of 364 cases.

AIMS: We aimed to study the clinicopathological and molecular features of high-grade non-anaplastic thyroid carcinomas (HGTCs), a carcinoma with a prognosis intermediate between those of well-differentiated carcinoma and anaplastic carcinoma. METHODS AND RESULTS: This study included 364 HGTC patients: 200 patients (54.9%) were diagnosed with poorly differentiated thyroid carcinoma (PDTC), based on the Turin consensus (HGTC-PDTC), and 164 were diagnosed with high-grade features that did not meet the Turin criteria (HGTC-nonPDTC). HGTCs are aggressive: the 3-year, 5-year, 10-year and 20-year disease-specific survival (DSS) rates were 89%, 76%, 60%, and 35%, respectively. Although DSS was similar between HGTC-PDTC and HGTC-nonPDTC patients, HGTC-PDTC was associated with higher rate of radioactive iodine avidity, a higher frequency of RAS mutations, a lower frequency of BRAF V600E mutations and a higher propensity for distant metastasis (DM) than HGTC-nonPDTC. Independent clinicopathological markers of worse outcome were: older age, male sex, extensive necrosis and lack of encapsulation for DSS; older age, male sex and vascular invasion for DM-free survival; and older age, necrosis, positive margins and lymph node metastasis for locoregional recurrence-free survival. The frequencies of BRAF, RAS, TERT, TP53 and PTEN alterations were 28%, 40%, 55%, 11%, and 10%, respectively. TP53, PTEN and TERT were independent molecular markers associated with an unfavourable outcome, independently of clinicopathological parameters. The coexistence of BRAF V600E and TERT promoter mutation increased the risk of DM. CONCLUSIONS: The above data support the classification of HGTC as a single group with two distinct subtypes based on tumour differentiation: HGTC-PDTC and HGTC-nonPDTC.

NATIONAL SURVEY OF ENDOCRINOLOGISTS AND SURGEONS REGARDING ACTIVE SURVEILLANCE FOR LOW-RISK PAPILLARY THYROID CANCER.

OBJECTIVE: Active surveillance for low-risk papillary thyroid cancer (PTC) was endorsed by the American Thyroid Association guidelines in 2015. The attitudes and beliefs of physicians treating thyroid cancer regarding the active surveillance approach are not known. METHODS: A national survey of endocrinologists and surgeons treating thyroid cancer was conducted from August to September 2017 via professional society emails. This mixed-methods analysis reported attitudes toward potential factors impacting decision-making regarding active surveillance, beliefs about barriers and facilitators of its use, and reasons why physicians would pick a given management strategy for themselves if they were diagnosed with a low-risk PTC. Survey items about attitudes and beliefs were derived from the Cabana model of barriers to guideline adherence and theoretical domains framework of behavior change. RESULTS: Among 345 respondents, 324 (94%) agreed that active surveillance was appropriate for at least some patients, 81% agreed that active surveillance was at least somewhat underused, and 76% said that they would choose surgery for themselves if diagnosed with a PTC of ≤1 cm. Majority of the respondents believed that the guidelines supporting active surveillance were too vague and that the current supporting evidence was too weak. Malpractice and financial concerns were identified as additional barriers to offering active surveillance. The respondents endorsed improved information resources and evidence as possible facilitators to offering active surveillance. CONCLUSION: Although there is general support among physicians who treat low-risk PTC for the active surveillance approach, there is reluctance to offer it because of the lack of robust evidence, guidelines, and protocols.

Thermogravimetric Analysis and Mass Spectrometry Allow for Determination of Chemisorbed Reaction Products on Metal Organic Frameworks.

Thermogravimetric analysis (TGA) is a technique which can probe chemisorption of substrates onto metal organic frameworks. A TGA method was developed to examine the catalytic oxidation of S-nitrosoglutathione (GSNO) by the MOF H3[(Cu4Cl)3(BTTri)8] (abbr. Cu-BTTri; H3BTTri = 1,3,5-tris(1H-1,2,3-triazol-5-yl)benzene), yielding glutathione disulfide (GSSG) and nitric oxide (NO). Thermal analysis of reduced glutathione (GSH), GSSG, GSNO, and Cu-BTTri revealed thermal resolution of all four analytes through different thermal onset temperatures and weight percent changes. Two reaction systems were probed: an aerobic column flow reaction and an anaerobic solution batch reaction with gas agitation. In both systems, Cu-BTTri was reacted with a 1 mM GSH, GSSG, or GSNO solution, copiously rinsed with distilled-deionized water (dd-H2O), dried (25 °C, < 1 Torr), and assessed by TGA. Additionally, stock, effluent or supernatant, and rinse solutions for each glutathione derivative within each reaction system were assessed by mass spectrometry (MS) to inform on chemical transformations promoted by Cu-BTTri as well as relative analyte concentrations. Both reaction systems exhibited chemisorption of glutathione derivatives to the MOF by TGA. Mass spectrometry analyses revealed that in both systems, GSH was oxidized to GSSG, which chemisorbed to the MOF whereas GSSG remained unchanged during chemisorption. For GSNO, chemisorption to the MOF without reaction was observed in the aerobic column setup, whereas conversion to GSSG and subsequent chemisorption was observed in the anaerobic batch setup. These findings suggest that within this reaction system, GSSG is the primary adsorbent of concern with regards to strong binding to Cu-BTTri. Development of similar thermal methods could allow for the probing of MOF reactivity for a wide range of systems, informing on important considerations such as reduced catalytic efficiency from poisoning, recyclability, and loading capacities of contaminants or toxins with MOFs.

Comparative transcriptomics as a guide to natural product discovery and biosynthetic gene cluster functionality.

Bacterial natural products remain an important source of new medicines. DNA sequencing has revealed that a majority of natural product biosynthetic gene clusters (BGCs) maintained in bacterial genomes have yet to be linked to the small molecules whose biosynthesis they encode. Efforts to discover the products of these orphan BGCs are driving the development of genome mining techniques based on the premise that many are transcriptionally silent during normal laboratory cultivation. Here, we employ comparative transcriptomics to assess BGC expression among four closely related strains of marine bacteria belonging to the genus Salinispora The results reveal that slightly more than half of the BGCs are expressed at levels that should facilitate product detection. By comparing the expression profiles of similar gene clusters in different strains, we identified regulatory genes whose inactivation appears linked to cluster silencing. The significance of these subtle differences between expressed and silent BGCs could not have been predicted a priori and was only revealed by comparative transcriptomics. Evidence for the conservation of silent clusters among a larger number of strains for which genome sequences are available suggests they may be under different regulatory control from the expressed forms or that silencing may represent an underappreciated mechanism of gene cluster evolution. Coupling gene expression and metabolomics data established a bioinformatic link between the salinipostins and their associated BGC, while genetic manipulation established the genetic basis for this series of compounds, which were previously unknown from Salinispora pacifica.

Phase 2 study of vascular endothelial growth factor trap for the treatment of metastatic thyroid cancer.

BACKGROUND: Several multitargeted tyrosine kinase inhibitors (TKIs) have demonstrated activity in patients with thyroid cancer that is refractory to radioactive iodine (RAI). The antitumor effect is attributed at least in part to the ability of these TKIs to inhibit angiogenesis in these vascular tumors. Vascular endothelial growth factor (VEGF) Trap (VT) is a recombinantly produced fusion protein consisting solely of human sequences for VEGF receptors 1 and 2 extracellular domains and human immunoglobulin 1. Evaluating VT in patients with thyroid cancer is reasonable considering the activity observed with TKIs targeting VEGF. METHODS: The current study was a single-institution, phase 2, Simon 2-stage design (21 to >41 patients) study based on the objective response rate and/or 6-month progression-free survival as the primary endpoints. Eligible patients were required to have progressive, RAI-refractory and/or [18 F]fludeoxyglucose-avid, recurrent and/or metastatic, nonmedullary, nonanaplastic thyroid cancer; disease that was measurable using Response Evaluation Criteria In Solid Tumors (RECIST) criteria; and adequate organ and bone marrow function. VT at a dose of 4 mg/kg intravenously was administered every 14 days. RESULTS: A total of 40 patients were included in the analysis. Of these patients, 24 had papillary thyroid cancer, 2 had follicular thyroid cancer, and 11 had Hurthle cell thyroid cancer. The final 3 tumors were classified as poorly differentiated. There were no complete and/or partial responses noted; 34 patients achieved stable disease and 6 patients experienced disease progression as their best response. Of the 34 patients with stable disease, 16 remained on the study for >6 months and 6 patients remained on the study for >12 months. The median duration on treatment was 4.1 months (range, 0.6-30.8 months). CONCLUSIONS: Unlike TKIs, which have shown responses in this setting, to the authors' knowledge there have been no responses observed with the use of single-agent VT to date. It does not appear to be a promising drug for the treatment of patients with thyroid cancer.

Detection of Natural Products and Their Producers in Ocean Sediments.

Thousands of natural products have been identified from cultured microorganisms, yet evidence of their production in the environment has proven elusive. Technological advances in mass spectrometry, combined with public databases, now make it possible to address this disparity by detecting compounds directly from environmental samples. Here, we used adsorbent resins, tandem mass spectrometry, and next-generation sequencing to assess the metabolome of marine sediments and its relationship to bacterial community structure. We identified natural products previously reported from cultured bacteria, providing evidence they are produced in situ, and compounds of anthropogenic origin, suggesting this approach can be used as an indicator of environmental impact. The bacterial metabolite staurosporine was quantified and shown to reach physiologically relevant concentrations, indicating that it may influence sediment community structure. Staurosporine concentrations were correlated with the relative abundance of the staurosporine-producing bacterial genus Salinispora and production confirmed in strains cultured from the same location, providing a link between compound and candidate producer. Metagenomic analyses revealed numerous biosynthetic gene clusters related to indolocarbazole biosynthesis, providing evidence for noncanonical sources of staurosporine and a path forward to assess the relationships between natural products and the organisms that produce them. Untargeted environmental metabolomics circumvents the need for laboratory cultivation and represents a promising approach to understanding the functional roles of natural products in shaping microbial community structure in marine sediments.IMPORTANCE Natural products are readily isolated from cultured bacteria and exploited for useful purposes, including drug discovery. However, these compounds are rarely detected in the environments from which the bacteria are obtained, thus limiting our understanding of their ecological significance. Here, we used environmental metabolomics to directly assess chemical diversity in marine sediments. We identified numerous metabolites and, in one case, isolated strains of bacteria capable of producing one of the compounds detected. Coupling environmental metabolomics with community and metagenomic analyses provides opportunities to link compounds and producers and begin to assess the complex interactions mediated by specialized metabolites in marine sediments.

Prolongation of tumour volume doubling time (midDT) is associated with improvement in disease-specific survival in patients with rapidly progressive radioactive iodine refractory differentiated thyroid cancer selected for molecular targeted therapy.

PURPOSE: To assess molecular targeted therapy (MTT)'s ability to affect tumour volume doubling time (TVDT) and disease-specific survival (DSS) in patients presenting with lung metastasis from radioactive iodine refractory progressive thyroid cancer. METHODS: In this retrospective study, we examined the clinical characteristics, average tumour volume doubling times of lung metastasis and disease-specific survival of patients with lung metastasis from differentiated thyroid cancer who were treated with MTT. RESULTS: The 5-year DSS from the distant metastasis (DM) diagnosis was 72% with median survival of 8 years (95% CI: 6.6-9.5). The median survival was 2.9 years after MTT start (95% CI: 2.1-3.6). On MTT, lung average tumour volume doubling time (midDT) was prolonged to midDT ≥3 years in 75% of patients with baseline midDT ≤1 year and 100% of patients with midDT 1-3 years. In patients with rapidly progressive thyroid cancer (midDT ≤1 year at baseline), the median survival was 4.5 years in those with MTT-achieved midDT ≥3 years (95% CI: 2.9-6.2), as opposed to 2.3 years (95% CI: 0.3-4.3) and 0.7 years (95% CI: 0.2-1.3) in those with MTT-achieved midDT of 1-3 years and MTT-achieved midDT ≤1 year, respectively (log rank P < 0.001). CONCLUSION: Lung midDT is a useful and important clinical marker of disease-specific survival for patients with progressive radioactive iodine refractory (RAIR) metastatic thyroid cancer. In patients with rapidly progressive metastatic RAIR thyroid cancer, molecular targeted therapy prolongs lung tumour volume doubling time and is associated with improved disease-specific survival.

Surgical considerations for papillary thyroid microcarcinomas.

We reevaluate current treatment recommendations of papillary thyroid microcarcinomas taking into account the indolent behavior of these tumors, and the potential morbidity that may result from an unnecessary surgery. The goals of this communication are to: 1) provide surgeons and endocrinologists with the most up-to-date evidence on management of microcarcinomas, 2) outline appropriate instances for active surveillance, and 3) describe the role of surgical interventions for microcarcinomas including lobectomy, total thyroidectomy, and central neck dissection.

Mass Spectrometry-Based Visualization of Molecules Associated with Human Habitats.

The cars we drive, the homes we live in, the restaurants we visit, and the laboratories and offices we work in are all a part of the modern human habitat. Remarkably, little is known about the diversity of chemicals present in these environments and to what degree molecules from our bodies influence the built environment that surrounds us and vice versa. We therefore set out to visualize the chemical diversity of five built human habitats together with their occupants, to provide a snapshot of the various molecules to which humans are exposed on a daily basis. The molecular inventory was obtained through untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of samples from each human habitat and from the people that occupy those habitats. Mapping MS-derived data onto 3D models of the environments showed that frequently touched surfaces, such as handles (e.g., door, bicycle), resemble the molecular fingerprint of the human skin more closely than other surfaces that are less frequently in direct contact with humans (e.g., wall, bicycle frame). Approximately 50% of the MS/MS spectra detected were shared between people and the environment. Personal care products, plasticizers, cleaning supplies, food, food additives, and even medications that were found to be a part of the human habitat. The annotations indicate that significant transfer of chemicals takes place between us and our built environment. The workflows applied here will lay the foundation for future studies of molecular distributions in medical, forensic, architectural, space exploration, and environmental applications.

Role of RAI in the management of incidental N1a disease in papillary thyroid cancer.

BACKGROUND: Following total thyroidectomy (TT) for papillary thyroid cancer (PTC), pathological assessment can occasionally reveal incidental perithyroidal lymph nodes (LNs) with occult metastases. These cN0pN1a patients often receive radioactive iodine (RAI) therapy for this indication alone. The aim of this study was to determine the central compartment nodal recurrence-free survival in patients treated without RAI compared to those who received RAI treatment. METHODS: An institutional database of 3664 previously untreated patients with differentiated thyroid cancer operated between 1986 and 2010 was reviewed. A total of 232 pT1-3 patients managed with TT and no neck dissection were subsequently found to have incidental level 6 LNs on pathology. Patients with other indications for RAI, such as extrathyroidal extension and close or positive margins, were excluded. One hundred and four patients remained for analysis. Kaplan-Meier method was used to determine central neck LN recurrence-free survival (RFS). RESULTS: The median age of the cohort was 40 years (range 17-83). The median follow-up was 53 months (range 1-211). The median number of positive LNs removed and maximum LN diameter were 1 (range 1-8) and 5 mm (range 1-16 mm), respectively. A total of 67 (64%) patients had adjuvant RAI and 37 (36%) did not. Patients with vascular invasion (P = 0·01), LNs >2 mm (P = 0·07) and >2 positive nodes (P = 0·06) were more likely to be selected for adjuvant RAI therapy. Patients without RAI therapy had similar 5-year central neck LN RFS compared to those treated with RAI: 96·2% vs 94·6%, respectively (P = 0·92). CONCLUSION: There is no difference in the 5-year central compartment nodal recurrence-free survival in patients treated without RAI compared to those who received RAI treatment.

Patterns, causes and consequences of defensive microbiome dynamics across multiple scales.

The microbiome can significantly impact host phenotypes and serve as an additional source of heritable genetic variation. While patterns across eukaryotes are consistent with a role for symbiotic microbes in host macroevolution, few studies have examined symbiont-driven host evolution or the ecological implications of a dynamic microbiome across temporal, spatial or ecological scales. The pea aphid, Acyrthosiphon pisum, and its eight heritable bacterial endosymbionts have served as a model for studies on symbiosis and its potential contributions to host ecology and evolution. But we know little about the natural dynamics or ecological impacts of the heritable microbiome of this cosmopolitan insect pest. Here we report seasonal shifts in the frequencies of heritable defensive bacteria from natural pea aphid populations across two host races and geographic regions. Microbiome dynamics were consistent with symbiont responses to host-level selection and findings from one population suggested symbiont-driven adaptation to seasonally changing parasitoid pressures. Conversely, symbiont levels were negatively correlated with enemy-driven mortality when measured across host races, suggesting important ecological impacts of host race microbiome divergence. Rapid drops in symbiont frequencies following seasonal peaks suggest microbiome instability in several populations, with potentially large costs of 'superinfection' under certain environmental conditions. In summary, the realization of several laboratory-derived, a priori expectations suggests important natural impacts of defensive symbionts in host-enemy eco-evolutionary feedbacks. Yet negative findings and unanticipated correlations suggest complexities within this system may limit or obscure symbiont-driven contemporary evolution, a finding of broad significance given the widespread nature of defensive microbes across plants and animals.

Undetectable Thyroglobulin Levels in Poorly Differentiated Thyroid Carcinoma Patients Free of Macroscopic Disease After Initial Treatment: Are They Useful?

BACKGROUND: Predictive role of undetectable thyroglobulin (Tg) in patients with poorly differentiated thyroid carcinoma (PDTC) is unclear. Our goal was to report on Tg levels following total thyroidectomy and adjuvant RAI in PDTC patients and to correlate Tg levels with recurrence. METHODS: Forty patients with PDTC with no distant metastases at presentation (M0) and managed by total thyroidectomy and adjuvant RAI were identified from a database of 91 PDTC patients. Of these, 31 patients had Tg values recorded and formed the basis of our analysis. A nonstimulated Tg level <1 ng/ml was used as a cutoff point for undetectable Tg levels. Association of patient and tumor characteristics with Tg levels was examined by χ (2) test. Recurrence-free survival (RFS) stratified by postop Tg level was calculated by Kaplan-Meier method and compared by log-rank test. RESULTS: Twenty patients had undetectable Tg (<1 ng/ml) and 11 had detectable Tg (≥1 ng/ml; range 2-129 ng/ml) following surgery. After adjuvant RAI, 24 patients had undetectable Tg (<1 ng/ml) and 7 had detectable Tg (≥1 ng/ml; range 1-57 ng/ml). Patients with undetectable Tg were less likely to have pathologically positive margins compared to those with detectable Tg (33 vs. 72 % respectively; p = 0.03). Patients with undetectable Tg levels had better 5-year regional control and distant control than patients with detectable Tg level (5-year regional recurrence-free survival 96 vs. 69 %; p = 0.03; 5-year distant recurrence-free survival 96 vs. 46 %, p = 0.11). CONCLUSION: Postoperative thyroglobulin levels in subset of patients with PDTC appear to have predictive value for recurrence. Patients with undetectable Tg have a low rate of recurrence.

Integration of a postoperative calcitonin measurement into an anatomical staging system improves initial risk stratification in medullary thyroid cancer.

OBJECTIVE: Staging systems applied to medullary thyroid cancer (MTC) rely on initial clinical and pathological features and do not consider the response to treatment. To determine whether MTC staging can be improved by incorporating the first postoperative calcitonin measurement. PATIENTS AND MEASUREMENTS: Eighty-five patients being monitored for MTC (median follow-up 5 years) were retrospectively classified according to both the American Joint Committee on Cancer (AJCC) and the proposed combined risk stratification system (low, intermediate and high risk), which incorporates the first postoperative calcitonin measurement, using the outcomes no evidence of disease (NED), biochemical evidence of disease, structurally identifiable disease and death. RESULTS: Ninety per cent of AJCC I patients were classified as NED at final follow-up. When we added a postoperative calcitonin measurement, 95% low-risk patients were classified as NED at final follow-up. AJCC stages I and IV were associated, respectively, with no occurrence and a high rate (63%) of structurally identifiable disease. Stages II and III yielded similar predictions of structurally identifiable disease, 13% and 14%, respectively. When we included the postoperative calcitonin level, the patients with structural evidence of disease included none from the low-risk group, 10% from the intermediate group and 63% from the high-risk group. The proportion of variance explained analysis (PVE) was better for the combined risk stratification system (54%) than for the AJCC system alone (32%). CONCLUSION: Including the first postoperative calcitonin measurement with the anatomical staging system can better predict the clinical outcome of patients with MTC and refine the follow-up of these patients.

Copper(II) Ions Originating from CuBTC MOF Act as a Soluble Catalyst in the Friedländer Synthesis.

The copper-based metal-organic framework (MOF), CuBTC (where H3BTC = benzene-1,3,5-tricarboxylate), has been reported as a reusable heterogeneous catalyst for the Friedländer synthesis of substituted quinolines, which are desirable targets in the pharmaceutical industry. Because of this application, we further investigated the CuBTC-catalyzed Friedländer synthesis of 3-acetyl-2-methyl-4-phenylquinoline. CuBTC was synthesized in-house and used as a catalyst for the Friedländer synthesis. Fresh and used CuBTC were analyzed using scanning electron microscopy (SEM), powder X-ray diffraction (pXRD), and X-ray photoelectron spectroscopy (XPS). The used CuBTC shows structural breakdown in pXRD patterns and SEM images. Despite the structural breakdown, the desired product, 3-acetyl-2-methyl-4-phenylquinoline, is still produced in a moderate yield (76.3% ± 0.2), as confirmed via time-of-flight mass spectrometry and nuclear magnetic resonance spectroscopy. Inductively coupled plasma atomic emission spectroscopy of the recovered supernatant solution indicates the presence of copper(II) ions in solution. Thus, we hypothesized that the standard Friedländer conditions may degrade the CuBTC framework, resulting in copper(II) ions in solution. Control experiments with copper(II) from Cu(NO3)2·3H2O catalyzes the Friedländer reaction in yields (75.6% ± 0.1) equal to that of the CuBTC MOF. Overall, our findings suggest that CuBTC acts as a copper(II) source, and the copper(II) ions originating from the CuBTC MOF are responsible for the observed catalysis.

Surface Modification of Oxygenator Fibers with a Catalytically Active Metal-Organic Framework to Generate Nitric Oxide: An Ex Vivo Pilot Study.

Coating all portions of an extracorporeal membrane oxygenation (ECMO) circuit with materials exhibiting inherent, permanent antithrombotic properties is an essential step to prevent thrombus-induced complications. However, developing antithrombotic coatings for oxygenator fibers within membrane oxygenators of ECMO systems has proven challenging. We have used polydopamine (PDA) to coat oxygenator fibers and immobilize a Cu-based metal-organic framework (MOF) on the surface to act as a nitric oxide (NO) catalyst. Importantly, the PDA/MOF coating will produce NO indefinitely from endogenous S-nitrosothiols and it has not previously been applied to ECMO oxygenator fibers.

Psychological adjustment to initial treatment for low-risk thyroid cancer: Preliminary study.

BACKGROUND: Low-risk papillary thyroid carcinoma (LR-PTC) can be managed by immediate surgery (IS) or active surveillance (AS). We compare the psychological impact of these treatments on patients with LR-PTC. METHODS: Psychological data were collected over 1 year, with assessments at the time of treatment decision (T1), at 6 months (T2) and 12 months (T3) follow-up. Assessments included 13 validated psychological tools. RESULTS: Of 27 enrolled patients, 20 chose AS and 7 chose IS. The average times to T2 and T3 were 5.7 and 11.3 months, respectively. For both groups, Impact of Events Scale scores significantly decreased (p = 0.001) at T2, and depressive/anxiety symptoms remained low. CONCLUSIONS: This study demonstrates the feasibility of assessing psychological outcomes among patients treated for LR-PTC. Further studies are needed to evaluate the impact of AS versus IS on quality of life and changes that patients experience over longer time periods following their treatment decision.

Mixed Metal-Organic Framework Mixed-Matrix Membranes: Insights into Simultaneous Moisture-Triggered and Catalytic Delivery of Nitric Oxide using Cryo-scanning Electron Microscopy.

The fundamental chemical and structural diversity of metal-organic frameworks (MOFs) is vast, but there is a lack of industrial adoption of these extremely versatile compounds. To bridge the gap between basic research and industry, MOF powders must be formulated into more application-relevant shapes and/or composites. Successful incorporation of varying ratios of two different MOFs, CPO-27-Ni and CuBTTri, in a thin polymer film represents an important step toward the development of mixed MOF mixed-matrix membranes. To gain insight into the distribution of the two different MOFs in the polymer, we report their investigation by Cryo-scanning electron microscopy (Cryo-SEM) tomography, which minimizes surface charging and electron beam-induced damage. Because the MOFs are based on two different metal ions, Ni and Cu, the elemental maps of the MOF composite cross sections clearly identify the size and location of each MOF in the reconstructed 3D model. The tomography run was about six times faster than conventional focused ion beam (FIB)-SEM and the first insights to image segmentation combined with machine learning could be achieved. To verify that the MOF composites combined the benefits of rapid moisture-triggered release of nitric oxide (NO) from CPO-27-Ni with the continuous catalytic generation of NO from CuBTTri, we characterized their ability to deliver NO individually and simultaneously. These MOF composites show great promise to achieve optimal dual NO delivery in real-world medical applications.