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The uranium-containing molecules US2, OUS, and USe have been investigated using a pulsed laser ablation supersonic beam molecular source with time-of-flight mass spectrometric detection. Spectra have been recorded using the resonant two-photon ionization method over the spectroscopic range from 277 to 238 nm. These species have a myriad of excited electronic states in this spectroscopic region, leading to spectra that are highly congested and appear quasicontinuous. Sharp predissociation thresholds are observed, allowing precise bond dissociation energies to be measured. In the case of the triatomic molecules, it was necessary to use one laser for excitation and a delayed laser for ionization in order to observe a sharp predissociation threshold that allowed a precise bond dissociation energy to be measured. The resulting thermochemical values are D0(SU-S) = 4.910 ± 0.003 eV, D0(OU-S) = 5.035 ± 0.004 eV, and D0(USe) = 4.609 ± 0.009 eV. These results provide the first measurement of D0(USe) and reduce the error limits in the previous values of D0(SU-S) and D0(OU-S) by a factor of more than 70.
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In the present work, the electronic structure and chemical bonding of the MoC X3Σ- ground state and the six lowest excited states, A3Δ, a1Γ, b5Σ-, c1Δ, d1Σ+, and e5Π, have been investigated in detail using multireference configuration interaction methods and basis sets, including relativistic effective core potentials. In addition, scalar relativistic effects have been considered in the second order Douglas-Kroll-Hess approximation, while spin-orbit coupling has also been calculated. Five of the investigated states, X3Σ-, A3Δ, a1Γ, c1Δ, and d1Σ+, present quadruple σ2σ2π2π2 bonds. Experimentally, the predissociation threshold of MoC was measured using resonant two-photon ionization spectroscopy, allowing for a precise measurement of the dissociation energy of the ground state. Theoretically, the complete basis set limit of the calculated dissociation energy with respect to the atomic ground state products, including corrections for scalar relativistic effects, De(D0), is computed as 5.13(5.06) eV, in excellent agreement with our measured value of D0(MoC) of 5.136(5) eV. Furthermore, the calculated dissociation energies of the states having quadruple bonds with respect to their adiabatic atomic products range from 6.22 to 7.23 eV. The excited electronic states A3Δ2 and c1Δ2 are calculated to lie at 3899 and 8057 cm-1, also in excellent agreement with the experimental values of DaBell et al., 4002.5 and 7834 cm-1, respectively.
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The HIV-1 nucleocapsid protein (NC) is a multifunctional viral protein necessary for HIV-1 replication. Recent studies have demonstrated that reverse transcription (RT) completes in the intact viral capsid, and the timing of RT and uncoating are correlated. How the small viral core stably contains the ~10 kbp double stranded (ds) DNA product of RT, and the role of NC in this process, are not well understood. We showed previously that NC binds and saturates dsDNA in a non-specific electrostatic binding mode that triggers uniform DNA self-attraction, condensing dsDNA into a tight globule against extending forces up to 10 pN. In this study, we use optical tweezers and atomic force microscopy to characterize the role of NC's basic residues in dsDNA condensation. Basic residue mutations of NC lead to defective interaction with the dsDNA substrate, with the constant force plateau condensation observed with wild-type (WT) NC missing or diminished. These results suggest that NC's high positive charge is essential to its dsDNA condensing activity, and electrostatic interactions involving NC's basic residues are responsible in large part for the conformation, size, and stability of the dsDNA-protein complex inside the viral core. We observe DNA re-solubilization and charge reversal in the presence of excess NC, consistent with the electrostatic nature of NC-induced DNA condensation. Previous studies of HIV-1 replication in the presence of the same cationic residue mutations in NC showed significant defects in both single- and multiple-round viral infectivity. Although NC participates in many stages of viral replication, our results are consistent with the hypothesis that cationic residue mutations inhibit genomic DNA condensation, resulting in increased premature capsid uncoating and contributing to viral replication defects.
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ADN Viral , VIH-1 , Transcripción Reversa , VIH-1/genética , VIH-1/fisiología , VIH-1/química , VIH-1/metabolismo , ADN Viral/genética , ADN Viral/metabolismo , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/metabolismo , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/química , Humanos , Cationes/metabolismo , Replicación Viral , Microscopía de Fuerza Atómica , Virión/metabolismo , Virión/genética , Virión/química , MutaciónRESUMEN
BACKGROUND: Despite a higher risk of classical Hodgkin lymphoma (cHL) in people with HIV and the demonstrated safety and efficacy of PD-1 blockade in cHL, there are limited data on the use of these agents in HIV-associated cHL (HIV-cHL). PATIENTS/METHODS: We retrospectively identified patients with HIV-cHL from the "Cancer Therapy using Checkpoint inhibitors in People with HIV-International (CATCH-IT)" database who received nivolumab or pembrolizumab, alone or in combination with other agents, and reviewed records for demographics, disease characteristics, immune-mediated adverse events (imAEs), and treatment outcomes. Changes in CD4+ T-cell counts with treatment were measured via Wilcoxon signed-rank tests. Overall response rate (ORR) was defined as the proportion of patients with partial or complete response (PR/CR) per 2014 Lugano classification. RESULTS: We identified 23 patients with HIV-cHL who received a median of 6 cycles of PD-1 blockade: 1 as 1st-line, 6 as 2nd-line, and 16 as ≥3rd-line therapy. Seventeen (74%) patients received monotherapy, 5 (22%) received nivolumab plus brentuximab vedotin, and 1 received nivolumab plus ifosfamide, carboplatin, and etoposide. The median baseline CD4+ T-cell count was 155 cells/µL, which increased to 310 cells/µL at end-of-treatment (P = .009). Three patients had grade 3 imAEs; none required treatment discontinuation. The ORR was 83% with median duration of response of 19.7 months. The median progression-free survival was 21.2 months and did not differ between patients with <200 versus ≥200 CD4+ cells/µL (P = .95). CONCLUSION: Our findings support the use of PD-1 blockade in HIV-cHL for the same indications as the general population with cHL.
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Infecciones por VIH , Enfermedad de Hodgkin , Inhibidores de Puntos de Control Inmunológico , Humanos , Masculino , Enfermedad de Hodgkin/tratamiento farmacológico , Femenino , Persona de Mediana Edad , Adulto , Estudios Retrospectivos , Estados Unidos , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/complicaciones , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inhibidores de Puntos de Control Inmunológico/efectos adversos , Inhibidores de Puntos de Control Inmunológico/farmacología , Nivolumab/uso terapéutico , Nivolumab/efectos adversos , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Anciano , Resultado del Tratamiento , Anticuerpos Monoclonales HumanizadosRESUMEN
HIV-1 cores, which contain the viral genome and replication machinery, must disassemble (uncoat) during viral replication. However, the viral and host factors that trigger uncoating remain unidentified. Recent studies show that infectious cores enter the nucleus and uncoat near the site of integration. Here, we show that efficient uncoating of nuclear cores requires synthesis of a double-stranded DNA (dsDNA) genome >3.5 kb and that the efficiency of uncoating correlates with genome size. Core disruption by capsid inhibitors releases viral DNA, some of which integrates. However, most of the viral DNA is degraded, indicating that the intact core safeguards viral DNA. Atomic force microscopy and core content estimation reveal that synthesis of full-length genomic dsDNA induces substantial internal strain on the core to promote uncoating. We conclude that HIV-1 cores protect viral DNA from degradation by host factors and that synthesis of long double-stranded reverse transcription products is required to trigger efficient HIV-1 uncoating.
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ADN Viral , VIH-1 , Transcripción Reversa , Desencapsidación Viral , VIH-1/fisiología , VIH-1/efectos de los fármacos , VIH-1/genética , Humanos , ADN Viral/genética , ADN Viral/metabolismo , Replicación Viral/efectos de los fármacos , Genoma Viral , Microscopía de Fuerza Atómica , Cápside/metabolismoRESUMEN
Bacteriophage T4 gene 32 protein (gp32) is a single-stranded DNA (ssDNA) binding protein essential for DNA replication. gp32 forms stable protein filaments on ssDNA through cooperative interactions between its core and N-terminal domain. gp32's C-terminal domain (CTD) is believed to primarily help coordinate DNA replication via direct interactions with constituents of the replisome. However, the exact mechanisms of these interactions are not known, and it is unclear how tightly-bound gp32 filaments are readily displaced from ssDNA as required for genomic processing. Here, we utilized truncated gp32 variants to demonstrate a key role of the CTD in regulating gp32 dissociation. Using optical tweezers, we probed the binding and dissociation dynamics of CTD-truncated gp32, *I, to an 8.1 knt ssDNA molecule and compared these measurements with those for full-length gp32. The *I-ssDNA helical filament becomes progressively unwound with increased protein concentration but remains significantly more stable than that of full-length, wild-type gp32. Protein oversaturation, concomitant with filament unwinding, facilitates rapid dissociation of full-length gp32 from across the entire ssDNA segment. In contrast, *I primarily unbinds slowly from only the ends of the cooperative clusters, regardless of the protein density and degree of DNA unwinding. Our results suggest that the CTD may constrain the relative twist angle of proteins within the ssDNA filament such that upon critical unwinding the cooperative interprotein interactions largely vanish, facilitating prompt removal of gp32. We propose a model of CTD-mediated gp32 displacement via internal restructuring of its filament, providing a mechanism for rapid ssDNA clearing during genomic processing.
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Bacteriófago T4 , ADN de Cadena Simple , Proteínas de Unión al ADN , Unión Proteica , Proteínas Virales , Bacteriófago T4/genética , Bacteriófago T4/metabolismo , Replicación del ADN , ADN de Cadena Simple/metabolismo , ADN de Cadena Simple/genética , ADN Viral/genética , ADN Viral/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/química , Pinzas Ópticas , Dominios Proteicos , Proteínas Virales/metabolismo , Proteínas Virales/genética , Proteínas Virales/químicaRESUMEN
The ionization energies (IEs) of RuC, RhC, OsC, IrC, and PtC are assigned by the measurement of their two-photon ionization thresholds. Although late transition metal-carbon bonds are of major importance in organometallic chemistry and catalysis, accurate and precise fundamental thermochemical data on these chemical bonds are mainly lacking in the literature. Based on their two-photon ionization thresholds, in this work, we assign IE(RuC) = 7.439(40) eV, IE(RhC) = 7.458(32) eV, IE(OsC) = 8.647(25) eV, IE(IrC) = 8.933(74) eV, and IE(PtC) = 9.397(32) eV. These experimentally derived IEs are further confirmed through quantum chemical calculations using coupled-cluster single double perturbative triple methods that are extrapolated to the complete basis set limit using a three-parameter mixed Gaussian/exponential extrapolation scheme and corrected for spin-orbit effects using a semiempirical method. The electronic structure and chemical bonding of these MC species are discussed in the context of these ionization energy measurements. The IEs of RuC, RhC, OsC, and IrC closely mirror the IEs of the corresponding transition metal atoms, suggesting that for these species, the (n + 1)s electrons of the transition metals are not significantly involved in chemical bonding.
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PURPOSE: Intrahepatic cholangiocarcinoma (ICCA) is characterized by significant phenotypic and clinical heterogeneities and poor response to systemic therapy, potentially related to underlying heterogeneity in oncogenic alterations. We aimed to characterize the genomic heterogeneity between primary tumors and advanced disease in patients with ICCA. METHODS: Biopsy-proven CCA specimens (primary tumor and paired advanced disease [metastatic disease, progressive disease on systemic therapy, or postoperative recurrence]) from two institutions were subjected to targeted next-generation sequencing. Overall concordance (oncogenic driver mutations, copy number alterations, and fusion events) and mutational concordance (only oncogenic mutations) were compared across paired samples. A subgroup analysis was performed on the basis of exposure to systemic therapy. Patients with extrahepatic CCA (ECCA) were included as a comparison group. RESULTS: Sample pairs from 65 patients with ICCA (n = 54) and ECCA (n = 11) were analyzed. The median time between sample collection was 19.6 months (range, 2.7-122.9). For the entire cohort, the overall oncogenic concordance was 49% and the mutational concordance was 62% between primary and advanced disease samples. Subgroup analyses of ICCA and ECCA revealed overall/mutational concordance rates of 47%/58% and 60%/84%, respectively. Oncogenic concordance was similarly low for pairs exposed to systemic therapy between sample collections (n = 50, 53% overall, 68% mutational). In patients treated with targeted therapy for IDH1/2 alterations (n = 6) or FGFR2 fusions (n = 3), there was 100% concordance between the primary and advanced disease specimens. In two patients, FGFR2 (n = 1) and IDH1 (n = 1) alterations were detected de novo in the advanced disease specimens. CONCLUSION: The results reflect a high degree of heterogeneity in ICCA and argue for reassessment of the dominant driver mutations with change in disease status.
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Neoplasias de los Conductos Biliares , Colangiocarcinoma , Humanos , Colangiocarcinoma/tratamiento farmacológico , Mutación , Conductos Biliares Intrahepáticos/patología , Neoplasias de los Conductos Biliares/genética , Neoplasias de los Conductos Biliares/patologíaRESUMEN
BACKGROUND: Pancreatic cancer is one of the deadliest cancer types and represents a major unmet medical need. CheckMate 032 investigated safety and efficacy of nivolumab monotherapy and nivolumab plus ipilimumab with/without cobimetinib in advanced/metastatic solid tumors, including pancreatic cancer. METHODS: In the original pancreatic cancer cohort, previously treated patients (≥1 prior regimen) with advanced/metastatic pancreatic adenocarcinoma were assigned to nivolumab 3 mg/kg every 2 weeks (monotherapy arm) or nivolumab 1 mg/kg and ipilimumab 1 mg/kg or 3 mg/kg every 3 weeks for four doses, followed by nivolumab 3 mg/kg every 2 weeks (combination arm). A subsequent modified pancreatic cohort (one or two prior regimens) received nivolumab 3 mg/kg every 2 weeks, ipilimumab 1 mg/kg every 6 weeks, and cobimetinib 60 mg orally once daily for 21 days on and 7 days off (triplet arm). The primary endpoint was investigator-assessed objective response rate (ORR). Secondary endpoints were investigator-assessed progression-free survival (PFS), PFS rate, overall survival (OS), OS rate, safety, and tolerability. Additionally, ORR, PFS, and duration of response were assessed by blinded independent central review (BICR) in the triplet arm. RESULTS: 18 patients received nivolumab monotherapy, 21 received nivolumab plus ipilimumab, and 30 received nivolumab plus ipilimumab plus cobimetinib. In the triplet arm, partial responses were observed in two patients per investigator (ORR 6.7% (95% CI 0.8% to 22.1%)) and in three patients per BICR (ORR 10% (95% CI 2.1% to 26.5%)); no responses were observed in the other arms. Median (95% CI) PFS per investigator was 1.4 (1.3 to 2.0), 1.4 (1.2 to 2.7), and 3.0 (1.5 to 4.1) months for the monotherapy, nivolumab plus ipilimumab, and triplet arms, respectively. Median (95% CI) OS was 5.1 (2.0 to 9.0) months, 4.0 (1.9 to 5.6) months, and 6.2 (3.9 to 11.4) months, respectively. Most treatment-related adverse events were grade 2 or less. CONCLUSIONS: Nivolumab with or without ipilimumab did not elicit objective responses in previously treated patients with advanced pancreatic adenocarcinoma, although three confirmed partial responses and manageable safety were observed with cobimetinib-containing triplet therapy. The small sample size and differences in baseline disease-specific characteristics between arms limit interpretation of these results.
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Adenocarcinoma , Azetidinas , Neoplasias Pancreáticas , Piperidinas , Humanos , Nivolumab/uso terapéutico , Ipilimumab/efectos adversos , Adenocarcinoma/tratamiento farmacológico , Neoplasias Pancreáticas/tratamiento farmacológicoRESUMEN
OBJECTIVE: To assess the expression pattern of X-linked inhibitor of apoptosis protein (XIAP), a cellular stress sensor, and delineate the associated changes in the tumor immune microenvironment (TiME) for prognostic value and new therapeutic targets in inflammatory breast cancer (IBC). METHODS: Immunohistochemistry was conducted to assess the spatial localization of immune subsets, XIAP, and PDL1 expression in IBC and non-inflammatory breast cancer (nIBC) pretreatment tumors (n = 142). Validation and further exploration were performed by gene expression analysis of patient tumors along with signaling studies in a co-culture model. RESULTS: High XIAP in 37/81 IBC patients correlated significantly with high PD-L1, increased infiltration of FOXP3+ Tregs, CD163+ tumor-associated macrophages (TAMs), low CD8/CD163 ratio in both tumor stroma (TS) and invasive margins (IM), and higher CD8+ T cells and CD79α+ B cells in the IM. Gene set enrichment analysis identified cellular stress response- and inflammation-related genes along with tumor necrosis factor receptor 1 (TNFR1) expression in high-XIAP IBC tumors. Induction of TNFR1 and XIAP was observed when patient-derived SUM149 IBC cells were co-cultured with human macrophage-conditioned media simulating TAMs, further demonstrating that the TNF-α signaling pathway is a likely candidate governing TAM-induced XIAP overexpression in IBC cells. Finally, addition of Birinapant, a pan IAP antagonist, induced cell death in the pro-survival cytokine-enriched conditions. CONCLUSION: Using immunophenotyping and gene expression analysis in patient biospecimens along with in silico modeling and a preclinical model with a pan-IAP antagonist, this study revealed an interplay between increased TAMs, TNF-α signaling, and XIAP activation during (immune) stress in IBC. These data demonstrate the potential of IAP antagonists as immunomodulators for improving IBC therapeutic regimens.
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ER+ breast cancers (BC) are characterized by the elevated expression and signaling of estrogen receptor alpha (ESR1), which renders them sensitive to anti-endocrine therapy. While these therapies are clinically effective, prolonged treatment inevitably results in therapeutic resistance, which can occur through the emergence of gain-of-function mutations in ESR1. The central importance of ESR1 and development of mutated forms of ESR1 suggest that vaccines targeting these proteins could potentially be effective in preventing or treating endocrine resistance. To explore the potential of this approach, we developed several recombinant vaccines encoding different mutant forms of ESR1 (ESR1mut) and validated their ability to elicit ESR1-specific T cell responses. We then developed novel ESR1mut-expressing murine mammary cancer models to test the anti-tumor potential of ESR1mut vaccines. We found that these vaccines could suppress tumor growth, ESR1mut expression and estrogen signaling in vivo. To illustrate the applicability of these findings, we utilize HPLC to demonstrate the presentation of ESR1 and ESR1mut peptides on human ER+ BC cell MHC complexes. We then show the presence of human T cells reactive to ESR1mut epitopes in an ER+ BC patient. These findings support the development of ESR1mut vaccines, which we are testing in a Phase I clinical trial.
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Neoplasias de la Mama , Vacunas , Humanos , Animales , Ratones , Femenino , Neoplasias de la Mama/genética , Neoplasias de la Mama/terapia , Mutación , Estrógenos/uso terapéutico , Transducción de Señal , Vacunas/uso terapéuticoRESUMEN
Chloroquine has been used as a potent antimalarial, anticancer drug, and prophylactic. While chloroquine is known to interact with DNA, the details of DNA-ligand interactions have remained unclear. Here we characterize chloroquine-double-stranded DNA binding with four complementary approaches, including optical tweezers, atomic force microscopy, duplex DNA melting measurements, and isothermal titration calorimetry. We show that chloroquine intercalates into double stranded DNA (dsDNA) with a KD ~ 200 µM, and this binding is entropically driven. We propose that chloroquine-induced dsDNA intercalation, which happens in the same concentration range as its observed toxic effects on cells, is responsible for the drug's cytotoxicity.
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Antimaláricos , Antineoplásicos , Cloroquina/toxicidad , ADN/química , Antineoplásicos/toxicidad , CalorimetríaRESUMEN
Carcinoembryonic antigen (CEA) is a glycosylated cell surface oncofetal protein involved in adhesion, proliferation, and migration that is highly upregulated in multiple carcinomas and has long been a promising target for cancer vaccination. This review summarizes the progress to date in the development of CEA vaccines, examining both pre-clinical and clinical studies across a variety of vaccine platforms that in aggregate, begin to reveal some critical insights. These studies demonstrate the ability of CEA vaccines to break immunologic tolerance and elicit CEA-specific immunity, which associates with improved clinical outcomes in select individuals. Approaches that have combined replicating viral vectors, with heterologous boosting and different adjuvant strategies have been particularly promising but, these early clinical trial results will require confirmatory studies. Collectively, these studies suggest that clinical efficacy likely depends upon harnessing a potent vaccine combination in an appropriate clinical setting to fully realize the potential of CEA vaccination.
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Vacunas contra el Cáncer , Neoplasias , Humanos , Animales , Ratones , Antígeno Carcinoembrionario/genética , Neoplasias/terapia , Vectores Genéticos , Vacunación , Vacunas Sintéticas , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: The CLASP IID (Edwards PASCAL TrAnScatheter Valve RePair System Pivotal Clinical) trial is the first randomized controlled trial comparing the PASCAL system and the MitraClip system in prohibitive risk patients with significant symptomatic degenerative mitral regurgitation (DMR). OBJECTIVES: The study sought to report primary and secondary endpoints and 1-year outcomes for the full cohort of the CLASP IID trial. METHODS: Prohibitive-risk patients with 3+/4+ DMR were randomized 2:1 (PASCAL:MitraClip). One-year assessments included secondary effectiveness endpoints (mitral regurgitation [MR] ≤2+ and MR ≤1+), and clinical, echocardiographic, functional, and quality-of-life outcomes. Primary safety (30-day composite major adverse events [MAE]) and effectiveness (6-month MR ≤2+) endpoints were assessed for the full cohort. RESULTS: Three hundred patients were randomized (PASCAL: n = 204; MitraClip: n = 96). At 1 year, differences in survival, freedom from heart failure hospitalization, and MAE were nonsignificant (P > 0.05 for all). Noninferiority of the PASCAL system compared with the MitraClip system persisted for the primary endpoints in the full cohort (For PASCAL vs MitraClip, the 30-day MAE rates were 4.6% vs 5.4% with a rate difference of -0.8% and 95% upper confidence bound of 4.6%. The 6-month MR≤2+ rates were 97.9% vs 95.7% with a rate difference of 2.2% and 95% lower confidence bound (LCB) of -2.5%, for, respectively). Noninferiority was met for the secondary effectiveness endpoints at 1 year (MR≤2+ rates for PASCAL vs MitraClip were 95.8% vs 93.8% with a rate difference of 2.1% and 95% LCB of -4.1%. The MR≤1+ rates were 77.1% vs 71.3% with a rate difference of 5.8% and 95% LCB of -5.3%, respectively). Significant improvements in functional classification and quality of life were sustained in both groups (P <0.05 for all vs baseline). CONCLUSIONS: The CLASP IID trial full cohort met primary and secondary noninferiority endpoints, and at 1 year, the PASCAL system demonstrated high survival, significant MR reduction, and sustained improvements in functional and quality-of-life outcomes. Results affirm the PASCAL system as a beneficial therapy for prohibitive-surgical-risk patients with significant symptomatic DMR.
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Mechanical high-intensity focused ultrasound (M-HIFU), which includes histotripsy, is a non-ionizing, non-thermal ablation technology that can be delivered by noninvasive methods. Because acoustic cavitation is the primary mechanism of tissue disruption, histotripsy is distinct from the conventional HIFU techniques resulting in hyperthermia and thermal injury. Phase I human trials have shown the initial safety and efficacy of histotripsy in treating patients with malignant liver tumors. In addition to tissue ablation, a promising benefit of M-HIFU has been stimulating a local and systemic antitumor immune response in preclinical models and potentially in the Phase I trial. Preclinical studies combining systemic immune therapies appear promising, but clinical studies of combinations have been complicated by systemic toxicities. Consequently, combining M-HIFU with systemic immunotherapy has been demonstrated in preclinical models and may be testing in future clinical studies. An additional alternative is to combine intratumoral M-HIFU and immunotherapy using microcatheter-placed devices to deliver both M-HIFU and immunotherapy intratumorally. The promise of M-HIFU as a component of anti-cancer therapy is promising, but as forms of HIFU are tested in preclinical and clinical studies, investigators should report not only the parameters of the energy delivered but also details of the preclinical models to enable analysis of the immune responses. Ultimately, as clinical trials continue, clinical responses and immune analysis of patients undergoing M-HIFU including forms of histotripsy will provide opportunities to optimize clinical responses and to optimize application and scheduling of M-HIFU in the context of the multi-modality care of the cancer patient.
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Carcinoma Hepatocelular , Ultrasonido Enfocado de Alta Intensidad de Ablación , Neoplasias Hepáticas , Humanos , Ultrasonido Enfocado de Alta Intensidad de Ablación/métodos , InmunoterapiaRESUMEN
BACKGROUND: Roughly 5% of metastatic cancers present with uncertain origin, for which molecular classification could influence subsequent management; however, prior studies of molecular diagnostic classifiers have reported mixed results with regard to clinical impact. In this retrospective study, we evaluated the utility of a novel molecular diagnostic classifier by assessing theoretical changes in treatment and additional testing recommendations from oncologists before and after the review of classifier predictions. METHODS: We retrospectively analyzed de-identified records from 289 patients with a consensus diagnosis of cancer of uncertain/unknown primary (CUP). Two (or three, if adjudication was required) independent oncologists separately reviewed patient clinical information to determine the course of treatment before they reviewed results from the molecular diagnostic classifier and subsequently evaluated whether the predicted diagnosis would alter their treatment plan. RESULTS: Results from the molecular diagnostic classifier changed the consensus oncologist-reported treatment recommendations for 235 out of 289 patients (81.3%). At the level of individual oncologist reviews (n = 414), 64.7% (n = 268) of treatment recommendations were based on CUP guidelines prior to review of results from the molecular diagnostic classifier. After seeing classifier results, 98.1% (n = 207) of the reviews, where treatment was specified (n = 211), were guided by the tissue of origin-specific guidelines. Overall, 89.9% of the 414 total reviews either expressed strong agreement (n = 242) or agreement (n = 130) that the molecular diagnostic classifier result increased confidence in selecting the most appropriate treatment regimen. CONCLUSIONS: A retrospective review of CUP cases demonstrates that a novel molecular diagnostic classifier could affect treatment in the majority of patients, supporting its clinical utility. Further studies are needed to prospectively evaluate whether the use of molecular diagnostic classifiers improves clinical outcomes in CUP patients.
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Neoplasias Primarias Secundarias , Neoplasias Primarias Desconocidas , Humanos , Neoplasias Primarias Desconocidas/diagnóstico , Neoplasias Primarias Desconocidas/genética , Neoplasias Primarias Desconocidas/patología , Estudios Retrospectivos , Patología MolecularRESUMEN
BACKGROUND: Real-world applicability of the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) randomized controlled trial (RCT) has been debated because of careful patient selection and the contrasting results of the MITRA-FR (Multicentre Study of Percutaneous Mitral Valve Repair MitraClip Device in Patients with Severe Secondary Mitral Regurgitation) RCT. OBJECTIVES: The COAPT-PAS (COAPT Post-Approval Study) was initiated to assess the safety and effectiveness of the MitraClip in patients with secondary mitral regurgitation (SMR). METHODS: COAPT-PAS is a prospective, single-arm, observational study of 5,000 consecutive patients with SMR treated with the MitraClip at 406 U.S. centers participating in the TVT (Transcatheter Valve Therapy) registry from 2019 to 2020. The 1-year outcomes from the COAPT-PAS full cohort and the COAPT-like and MITRA-FR-like subgroups who met RCT inclusion/exclusion criteria are reported. RESULTS: Patients in the COAPT-PAS had more comorbidities, more severe HF and functional limitations, and less guideline-directed medical therapy than those in the COAPT or MITRA-FR RCTs. Patients in the COAPT-PAS full cohort and the COAPT-like (n = 991) and MITRA-FR-like (n = 917) subgroups achieved a 97.7% MitraClip implant rate, a similar and durable reduction of mitral regurgitation to ≤2+ at 1 year (90.7%, 89.7%, and 86.6%, respectively), a large improvement in quality of life at 1 year (Kansas City Cardiomyopathy Questionnaire +29 COAPT-PAS, +27 COAPT-like, and +33 MITRA-FR-like), faster procedure times, similar or lower clinical event rates compared with the RCTs' MitraClip arms, and lower clinical event rates than the RCTs' guideline-directed medical therapy only arms. One-year heart failure hospitalizations was 18.9% in COAPT-PAS, 19.7% in COAPT-like compared with 24.9% in COAPT-RCT, and 28.7% in COAPT-PAS-MITRA-FR-like compared with 47.4% in MITRA-FR-RCT. CONCLUSIONS: This large, contemporary, real-world study reinforces the safety and effectiveness of the MitraClip System in patients with SMR, including those who met the COAPT or MITRA-FR RCT inclusion/exclusion criteria and patients excluded from the RCTs.
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Insuficiencia Cardíaca , Insuficiencia de la Válvula Mitral , Humanos , Insuficiencia de la Válvula Mitral/cirugía , Hospitalización , Evaluación de Resultado en la Atención de Salud , Selección de PacienteRESUMEN
Single-stranded DNA-binding proteins (SSBs) are essential cellular components, binding to transiently exposed regions of single-stranded DNA (ssDNA) with high affinity and sequence non-specificity to coordinate DNA repair and replication. Escherichia coli SSB (EcSSB) is a homotetramer that wraps variable lengths of ssDNA in multiple conformations (typically occupying either 65 or 35 nt), which is well studied across experimental conditions of substrate length, salt, pH, temperature, etc. In this work, we use atomic force microscopy to investigate the binding of SSB to individual ssDNA molecules. We introduce non-canonical DNA bases that mimic naturally occurring DNA damage, synthetic abasic sites, as well as a non-DNA linker into our experimental constructs at sites predicted to interact with EcSSB. By measuring the fraction of DNA molecules with EcSSB bound as well as the volume of protein bound per DNA molecule, we determine the protein binding affinity, cooperativity, and conformation. We find that, with only one damaged nucleotide, the binding of EcSSB is unchanged relative to its binding to undamaged DNA. In the presence of either two tandem abasic sites or a non-DNA spacer, however, the binding affinity associated with a single EcSSB tetramer occupying the full substrate in the 65-nt mode is greatly reduced. In contrast, the binding of two EcSSB tetramers, each in the 35-nt mode, is preserved. Changes in the binding and cooperative behaviors of EcSSB across these constructs can inform how genomic repair and replication processes may change as environmental damage accumulates in DNA.
RESUMEN
Predissociation thresholds corresponding to dissociation at ground state separated atom limits (SALs) have been recorded in this group for more than 100 d- and f-block metal-containing molecules. The metal atom electronic degeneracies in these molecules generate a dense manifold of electronic states that allow high-lying vibronic levels to couple to pathways leading to dissociation. However, CrN, CuB, and AuB fail to dissociate at their ground SAL. Instead, the molecules remain bound at energies that far surpass their bond dissociation energies (BDEs), and their bonds break only when excited at or above an excited SAL. Sharp predissociation thresholds at excited SALs nevertheless allowed BDEs to be derived: D0(CrN): 3.941(22) eV; D0(CuB): 2.26(15) eV; D0(Au11B): 3.724(3) eV. A previous measurement of D0(AlCr) is re-evaluated as dissociating to a higher energy limit, giving a revised value of D0(AlCr) = 1.32(2) eV. A discussion of this physical behavior is presented.
RESUMEN
Bacteriophage T4 gene 32 protein (gp32) is a model single-stranded DNA (ssDNA) binding protein, essential for DNA replication. gp32 forms cooperative filaments on ssDNA through interprotein interactions between its core and N-terminus. However, detailed understanding of gp32 filament structure and organization remains incomplete, particularly for longer, biologically-relevant DNA lengths. Moreover, it is unclear how these tightly-bound filaments dissociate from ssDNA during complementary strand synthesis. We use optical tweezers and atomic force microscopy to probe the structure and binding dynamics of gp32 on long (â¼8 knt) ssDNA substrates. We find that cooperative binding of gp32 rigidifies ssDNA while also reducing its contour length, consistent with the ssDNA helically winding around the gp32 filament. While measured rates of gp32 binding and dissociation indicate nM binding affinity, at â¼1000-fold higher protein concentrations gp32 continues to bind into and restructure the gp32-ssDNA filament, leading to an increase in its helical pitch and elongation of the substrate. Furthermore, the oversaturated gp32-ssDNA filament becomes progressively unwound and unstable as observed by the appearance of a rapid, noncooperative protein dissociation phase not seen at lower complex saturation, suggesting a possible mechanism for prompt removal of gp32 from the overcrowded ssDNA in front of the polymerase during replication.