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1.
J Chem Phys ; 161(2)2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-38995083

RESUMO

We present the Python-based Molecule Builder for ESPResSo (pyMBE), an open source software application to design custom coarse-grained (CG) models, as well as pre-defined models of polyelectrolytes, peptides, and globular proteins in the Extensible Simulation Package for Research on Soft Matter (ESPResSo). The Python interface of ESPResSo offers a flexible framework, capable of building custom CG models from scratch. As a downside, building CG models from scratch is prone to mistakes, especially for newcomers in the field of CG modeling, or for molecules with complex architectures. The pyMBE module builds CG models in ESPResSo using a hierarchical bottom-up approach, providing a robust tool to automate the setup of CG models and helping new users prevent common mistakes. ESPResSo features the constant pH (cpH) and grand-reaction (G-RxMC) methods, which have been designed to study chemical reaction equilibria in macromolecular systems with many reactive species. However, setting up these methods for systems, which contain several types of reactive groups, is an error-prone task, especially for beginners. The pyMBE module enables the automatic setup of cpH and G-RxMC simulations in ESPResSo, lowering the barrier for newcomers and opening the door to investigate complex systems not studied with these methods yet. To demonstrate some of the applications of pyMBE, we showcase several case studies where we successfully reproduce previously published simulations of charge-regulating peptides and globular proteins in bulk solution and weak polyelectrolytes in dialysis. The pyMBE module is publicly available as a GitHub repository (https://github.com/pyMBE-dev/pyMBE), which includes its source code and various sample and test scripts, including the ones that we used to generate the data presented in this article.

2.
Phys Rev Lett ; 131(16): 168101, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37925715

RESUMO

Recent experiments on weak polyelectrolyte brushes found marked shifts in the effective pK_{a} that are linear in the logarithm of the salt concentration. Comparing explicit-particle simulations with mean-field calculations we show that for high grafting densities the salt concentration effect can be explained using the ideal Donnan theory, but for low grafting densities the full shift is due to a combination of the Donnan effect and the polyelectrolyte effect. The latter originates from electrostatic correlations that are neglected in the Donnan picture and that are only approximately included in the mean-field theory. Moreover, we demonstrate that the magnitude of the polyelectrolyte effect is almost invariant with respect to salt concentration but depends on the grafting density of the brush. This invariance is due to a complex cancellation of multiple effects. Based on our results, we show how the experimentally determined pK_{a} shifts may be used to infer the grafting density of brushes, a parameter that is difficult to measure directly.

3.
Soft Matter ; 19(19): 3522-3525, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37158282

RESUMO

Levin and Bakhshandeh suggested in their comment that (1), we stated in our recent review that pH-pKA is a universal parameter for titrating systems, that (2), we omitted to mention in our review the broken symmetry of the constant pH algorithm, and that (3), a constant pH simulation must include a grand-canonical exchange of ions with the reservoir. As a reply to (1), we point out that Levin and Bakhshandeh misquoted and hence invalidated our original statement. We therefore explain in detail under which circumstances pH-pKA can be a universal parameter, and also demonstrate why their numerical example is not in contradiction to our statement. Moreover, the fact that pH-pKA is not a universal parameter for titrating systems is well known in the pertinent literature. Regarding (2), we admit that the symmetry-breaking feature of the constant pH algorithm has escaped our attention at the time of writing the review. We added some clarifying remarks to this behavior. Concerning (3), we point out that the grand-canonical coupling and the resultant Donnan potential are not features of single-phase systems, but are essential for two-phase systems, as was shown in a recent paper by some of us, see J. Landsgesell et al., Macromolecules, 2020, 53, 3007-3020.

4.
J Chem Phys ; 159(1)2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37417757

RESUMO

We introduce a Monte-Carlo method that allows for the simulation of a polymeric phase containing a weak polyelectrolyte, which is coupled to a reservoir at a fixed pH, salt concentration, and total concentration of a weak polyprotic acid. The method generalizes the established grand-reaction method by Landsgesell et al. [Macromolecules 53, 3007-3020 (2020)] and, thus, allows for the simulation of polyelectrolyte systems coupled to reservoirs with a more complex chemical composition. In order to set the required input parameters that correspond to a desired reservoir composition, we propose a generalization of the recently published chemical potential tuning algorithm of Miles et al. [Phys. Rev. E 105, 045311 (2022)]. To test the proposed tuning procedure, we perform extensive numerical tests for both ideal and interacting systems. Finally, as a showcase, we apply the method to a simple test system that consists of a weak polybase solution that is coupled to a reservoir containing a small diprotic acid. The complex interplay of the ionization of various species, the electrostatic interactions, and the partitioning of small ions leads to a non-monotonous, stepwise swelling behavior of the weak polybase chains.


Assuntos
Polímeros , Cloreto de Sódio , Polieletrólitos , Íons , Simulação por Computador , Polímeros/química
5.
J Clin Gastroenterol ; 55(9): 792-797, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32947375

RESUMO

INTRODUCTION: Since 2001, device-assisted enteroscopy (DAE) has revolutionized the diagnostic and therapeutic capabilities for managing small bowel pathology. Though commonly performed, there have been no recent large studies to assess the use, yield, and risks of DAE and none that include all 3 DAE modalities. We hypothesized that DAE is safe with high diagnostic and therapeutic yields achieved within reasonable procedure duration and here we present a large retrospective multicenter US study evaluating the use, yield, and complications of DAE. METHODS: After obtaining institutional review board approval, electronic records were used to identify all DAE's performed for luminal small bowel evaluation in adult patients at 4 US referral centers (Duke University Medical Center, New York University Langone Medical Center, Louisiana State University Health Sciences Center, and University of Massachusetts Medical Center) from January 1, 2014 to January 1, 2019. Electronic medical records were reviewed to collect and analyze a variety of procedure-related outcomes. Using the data pooled across centers, descriptive statistics were generated for the patient and procedure-related characteristics and outcomes; relationships between characteristics and outcomes were explored. RESULTS: A total of 1787 DAE's were performed over this 5-year period (392 at Duke University Medical Center, 887 at Louisiana State University Health Sciences Center, 312 at New York University Langone Medical Center, and 195 at University of Massachusetts Medical Center). Of these, there were 1017 (57%) double-balloon, 391 (29%) single-balloon, and 378 (21%) spiral enteroscopies. The mean age of patients undergoing DAE was 66 years and 53% of examinations were performed on women; 18% of patients in the cohort underwent >1 DAE over this time span. A total of 53% of examinations were performed for suspected small bowel bleeding, 31% were directly guided by video capsule endoscopy findings and 8% were performed for abnormal imaging. A total of 85% of examinations used an antegrade approach and DAE took a mean of 45 minutes to complete; 76% of examinations revealed abnormal findings, with vascular, inflammatory, and neoplastic findings seen in 49%, 17%, and 15% of the cohort, respectively. Older age was significantly associated with any abnormal finding, including arteriovenous malformations (P<0.0001); 50% of examinations included a therapeutic maneuver, most commonly argon plasma coagulation/cautery (43%). There were complications in 16 examinations (0.9%) including 2 perforations (0.1%), 6 cases with bleeding (0.3%) and 1 episode of pancreatitis (0.1%). CONCLUSIONS: DAE is most commonly performed to evaluate suspected small bowel bleeding and is commonly directed by video capsule findings. DAE is safe, has a high diagnostic yield, with 76% of examinations showing abnormal findings, and frequently features therapeutic maneuvers. Advancing age is associated with abnormal findings on DAE.


Assuntos
Endoscopia por Cápsula , Enteropatias , Adulto , Idoso , Enteroscopia de Duplo Balão , Feminino , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/etiologia , Humanos , Enteropatias/diagnóstico , Intestino Delgado/diagnóstico por imagem , Estudos Retrospectivos , Estados Unidos
6.
Plant Dis ; 103(11): 2714-2732, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31560599

RESUMO

Among the biotic constraints of common mushroom (Agaricus bisporus) production, bacterial blotch is considered the most important mushroom disease in terms of global prevalence and economic impact. Etiology and management of bacterial blotch has been a major concern since its original description in 1915. Although Pseudomonas tolaasii is thought to be the main causal agent, various Pseudomonas species, as well as organisms from other genera have been reported to cause blotch symptoms on mushroom caps. In this review, we provide an updated overview on the etiology, epidemiology, and management strategies of bacterial blotch disease. First, diversity of the causal agent(s) and utility of high throughput sequencing-based approaches in the precise characterization and identification of blotch pathogen(s) is explained. Further, due to the limited options for use of conventional pesticides in mushroom farms against blotch pathogen(s), we highlight the role of balanced threshold of relative humidity and temperature in mushroom farms to combat the disease in organic and conventional production. Additionally, we discuss the possibility of the use of biological control agents (either antagonistic mushroom-associated bacterial strains or bacteriophages) for blotch management as one of the sustainable approaches for 21st century agriculture. Finally, we aim to elucidate the association of mushroom microbiome in cap development and productivity on one hand, and blotch incidence/outbreaks on the other hand.


Assuntos
Agaricus , Microbiologia de Alimentos , Pseudomonas , Microbiologia de Alimentos/tendências
7.
Cancer ; 123(13): 2489-2496, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28323339

RESUMO

BACKGROUND: Phase 3 trials have demonstrated a benefit from adjuvant radiation therapy (ART) for men who have adverse factors at radical prostatectomy (RP). However, some patients have a high risk of progression despite ART. The role of systemic therapy with ART in this high-risk group remains to be defined. METHODS: Patients who had either a post-RP prostate-specific antigen (PSA) nadir > 0.2 ng/mL and a Gleason score ≥7 or a PSA nadir ≤0.2 ng/mL, a Gleason score ≥8, and a pathologic tumor (pT) classification ≥ pT3 received 6 months of androgen-deprivation therapy (ADT) plus radiotherapy and 6 cycles of docetaxel. The primary objective was to assess whether the addition of ADT and docetaxel to ART resulted in a freedom from progression (FFP) rate ≥ 70% compared with an expected rate of 50%. Multivariate logistic and Cox regression analyses were used to model associations between factors and outcomes. RESULTS: In total, 74 patients were enrolled. The median follow-up was 4.4 years. The pathologic tumor classification was pT2 in 4% of patients, pT3 in 95%, and pT4 in 1%. The Gleason score was 7 in 18% of patients and ≥8 in 82%. Post-RP PSA levels were ≤0.2 ng/mL in 53% of patients and >0.2 ng/mL in 47%. The 3-year FFP rate was 73% (95% confidence interval, 61%-83%), and the 3-year cumulative incidence of biochemical, distant, and local failure was 26%, 7%, and 0%, respectively. In multivariate models, postprostatectomy PSA nadir was associated with 3-year FFP, Gleason score, and PSA with biochemical failure. Grade 3 and 4 neutropenia was common; however, only 3 episodes of febrile neutropenia occurred. Late toxicities were not impacted by the addition of systemic therapy. CONCLUSIONS: Combined ADT, docetaxel, and ART for men with high-risk prostate cancer after prostatectomy exceeded the prespecified study endpoint of 70% 3-year FFP. Phase 3 trials assessing combined local and systemic therapies for these high-risk patients are warranted. Cancer 2017;123:2489-96. © 2017 American Cancer Society.


Assuntos
Adenocarcinoma/terapia , Antagonistas de Androgênios/uso terapêutico , Anilidas/uso terapêutico , Antineoplásicos/uso terapêutico , Quimiorradioterapia Adjuvante/métodos , Nitrilas/uso terapêutico , Prostatectomia , Neoplasias da Próstata/terapia , Taxoides/uso terapêutico , Compostos de Tosil/uso terapêutico , Adenocarcinoma/sangue , Adenocarcinoma/patologia , Adulto , Idoso , Intervalo Livre de Doença , Docetaxel , Hormônio Liberador de Gonadotropina/agonistas , Humanos , Calicreínas/sangue , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Gradação de Tumores , Estadiamento de Neoplasias , Modelos de Riscos Proporcionais , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/patologia , Radioterapia Conformacional , Radioterapia de Intensidade Modulada
8.
Oncologist ; 21(6): 671-5, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27226359

RESUMO

BACKGROUND: Neuroendocrine tumors (NETs) are commonly treated with multimodality therapy. The combination of capecitabine and temozolomide (CAPTEM) has been suggested as a treatment option for patients with metastatic NETs. We present our experience with CAPTEM. METHODS: Data on NET patients who were placed on CAPTEM and received at least one cycle were obtained from a Velos eResearch database. Response rate was calculated by RECIST 1.1. Overall survival and progression-free survival (PFS) were calculated by the Kaplan-Meier survival method. RESULTS: A total of 29 patients (17 male and 12 female) were included. Median age at CAPTEM initiation was 58 years (range: 26-77). Primary tumors included 9 small bowel (31%), 15 pancreas (52%), 3 lung (10%), and 2 rectum (7%). Median number of CAPTEM cycles was 8 (range: 1-55). Partial response occurred in 5 patients (5 of 29, 17%); 14 patients (14 of 29, 48%) had stable disease, and 10 patients (10 of 29, 34%) had progressive disease. A total of 3 (20%) and 5 (33%) pancreatic NETs experienced partial response and stable disease, respectively. A total of 2 (14%) and 9 (64%) nonpancreatic NETs experienced partial response and stable disease, respectively. Partial response was noted in 1 patient (13%) and stable disease in 5 patients (63%) with Ki-67 values of less than 2%. In patients with Ki-67 values of 2%-20%, partial response was noted in 3 (19%) and stable disease in 8 (50%). Partial response and stable disease were noted in 1 patient each (20%) with Ki-67 values greater than 20%. Median PFS was 12 months. Adverse reactions caused dose reductions in 24% of patients. CONCLUSION: Although adverse reactions were experienced, most patients tolerated this regimen. CAPTEM should be considered as a reasonable treatment option for metastatic NET patients. IMPLICATIONS FOR PRACTICE: The role of chemotherapy in neuroendocrine tumors has evolved in recent years. The results of this study suggest that the combination of capecitabine and temozolomide provides an adequate treatment option and may prolong survival in patients with a wide variety of metastatic neuroendocrine tumors. Although prospective data are needed, this research adds to the abundance of retrospective experience with this combination that appears to show that capecitabine and temozolomide could potentially be an option for patients with advanced neuroendocrine tumors who have progressed on standard treatment.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Tumores Neuroendócrinos/tratamento farmacológico , Adulto , Idoso , Capecitabina/administração & dosagem , Capecitabina/efeitos adversos , Dacarbazina/administração & dosagem , Dacarbazina/efeitos adversos , Dacarbazina/análogos & derivados , Intervalo Livre de Doença , Feminino , Humanos , Antígeno Ki-67/análise , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Tumores Neuroendócrinos/mortalidade , Tumores Neuroendócrinos/patologia , Temozolomida
9.
Adv Exp Med Biol ; 767: 47-73, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23161006

RESUMO

Effective transcription, replication, and maintenance of the genome require a diverse set of molecular machines to perform the many chemical transactions that constitute these processes. Many of these machines use single-stranded nucleic acids as templates, and their actions are often regulated by the participation of nucleic acids in multimeric structures and macromolecular assemblies that restrict access to chemical information. Superfamily II (SF2) DNA helicases and translocases are a group of molecular machines that remodel nucleic acid lattices and enable essential cellular processes to use the information stored in the duplex DNA of the packaged genome. Characteristic accessory domains associated with the subgroups of the superfamily direct the activity of the common motor core and expand the repertoire of activities and substrates available to SF2 DNA helicases, translocases, and large multiprotein complexes containing SF2 motors. In recent years, single-molecule studies have contributed extensively to the characterization of this ubiquitous and essential class of enzymes.


Assuntos
DNA Helicases , Replicação do DNA , DNA/química , DNA Helicases/química
10.
J Sci Food Agric ; 93(9): 2188-200, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23371778

RESUMO

BACKGROUND: Source-separated food waste is increasingly being treated by means of hygienisation followed by anaerobic digestion. The fibrous digester residue (digestate) is a potential mushroom substrate, while heat from the biogas can provide steam for the cultivation process. Using bag experiments the present study explored digestate as a full substitute for chicken manure conventionally used in mushroom composts. RESULTS: After mixing, a rapid temperature development in the compost was stimulated by a small amount of chicken manure, as aerobic microbial seeding. Mechanical elimination of lumps was essential for full mycelial colonisation. Three straw digestate composts had Agaricus bisporus mushroom yields above 370 g kg⁻¹ substrate. The optimal compost water content was 600 g kg⁻¹ at inoculation, and high digestate content (up to 500 g kg⁻¹ by dry weight) did not affect yield for this species. High yields of A. subrufescens (200 g kg⁻¹) were related to drier composts of lower digestate content (more straw) and lower pH values at inoculation. CONCLUSION: Digestate successfully substituted chicken manure in straw composts without affecting mushroom yields for both species. There were no clear differences between straw digestate and control composts in terms of mushroom dry matter, size, nitrogen or ash content.


Assuntos
Agaricus/crescimento & desenvolvimento , Fertilizantes/análise , Qualidade dos Alimentos , Carpóforos/crescimento & desenvolvimento , Resíduos Industriais/análise , Microbiologia do Solo , Solo/química , Agaricus/química , Agaricus/metabolismo , Agricultura/economia , Animais , Sulfato de Cálcio/química , Fenômenos Químicos , Galinhas , Conservação de Recursos Energéticos , Fertilizantes/economia , Indústria de Processamento de Alimentos/economia , Agricultura Florestal/economia , Carpóforos/química , Carpóforos/metabolismo , Temperatura Alta , Hidrólise , Resíduos Industriais/economia , Esterco/microbiologia , Picea/química , Componentes Aéreos da Planta/química , Especificidade da Espécie , Triticum/química
11.
J Phys Chem B ; 127(25): 5601-5608, 2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37327109

RESUMO

NMR relaxometry is a powerful and well-established experimental approach for characterizing dynamic processes in soft matter systems. All-atom (AA) resolved simulations are typically employed to gain further microscopic insights while reproducing the relaxation rates R1. However, such approaches are limited to time and length scales that prevent to model systems such as long polymer chains or hydrogels. Coarse graining (CG) can overcome this barrier at the cost of losing atomistic details that impede the calculation of NMR relaxation rates. Here, we address this issue by performing a systematic characterization of dipolar relaxation rates R1 on a PEG-H2O mixture at two different levels of details: AA and CG. Remarkably, we show that NMR relaxation rates R1 obtained at the CG level obey the same trends when compared to AA calculations but with a systematic offset. This offset is due to, on the one hand, the lack of an intramonomer component and, on the other hand, the inexact positioning of the spin carriers. We show that the offset can be corrected for quantitatively by reconstructing a posteriori the atomistic details for the CG trajectories.

12.
J Clin Oncol ; 41(24): 4035-4044, 2023 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-37315297

RESUMO

PURPOSE: To determine whether addition of external beam radiation therapy (EBRT) to brachytherapy (BT) (COMBO) compared with BT alone would improve 5-year freedom from progression (FFP) in intermediate-risk prostate cancer. METHODS: Men with prostate cancer stage cT1c-T2bN0M0, Gleason Score (GS) 2-6 and prostate-specific antigen (PSA) 10-20 or GS 7, and PSA < 10 were eligible. The COMBO arm was EBRT (45 Gy in 25 fractions) to prostate and seminal vesicles followed by BT prostate boost (110 Gy if 125-Iodine, 100 Gy if 103-Pd). BT arm was delivered to prostate only (145 Gy if 125-Iodine, 125 Gy if 103-Pd). The primary end point was FFP: PSA failure (American Society for Therapeutic Radiology and Oncology [ASTRO] or Phoenix definitions), local failure, distant failure, or death. RESULTS: Five hundred eighty-eight men were randomly assigned; 579 were eligible: 287 and 292 in COMBO and BT arms, respectively. The median age was 67 years; 89.1% had PSA < 10 ng/mL, 89.1% had GS 7, and 66.7% had T1 disease. There were no differences in FFP. The 5-year FFP-ASTRO was 85.6% (95% CI, 81.4 to 89.7) with COMBO compared with 82.7% (95% CI, 78.3 to 87.1) with BT (odds ratio [OR], 0.80; 95% CI, 0.51 to 1.26; Greenwood T P = .18). The 5-year FFP-Phoenix was 88.0% (95% CI, 84.2 to 91.9) with COMBO compared with 85.5% (95% CI, 81.3 to 89.6) with BT (OR, 0.80; 95% CI, 0.49 to 1.30; Greenwood T P = .19). There were no differences in the rates of genitourinary (GU) or GI acute toxicities. The 5-year cumulative incidence for late GU/GI grade 2+ toxicity is 42.8% (95% CI, 37.0 to 48.6) for COMBO compared with 25.8% (95% CI, 20.9 to 31.0) for BT (P < .0001). The 5-year cumulative incidence for late GU/GI grade 3+ toxicity is 8.2% (95% CI, 5.4 to 11.8) compared with 3.8% (95% CI, 2.0 to 6.5; P = .006). CONCLUSION: Compared with BT, COMBO did not improve FFP for prostate cancer but caused greater toxicity. BT alone can be considered as a standard treatment for men with intermediate-risk prostate cancer.


Assuntos
Braquiterapia , Neoplasias da Próstata , Braquiterapia/efeitos adversos , Humanos , Neoplasias da Próstata/radioterapia , Antígeno Prostático Específico , Dosagem Radioterapêutica , Resultado do Tratamento , Masculino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais
13.
Int J Radiat Oncol Biol Phys ; 112(5): 1115-1122, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34740768

RESUMO

PURPOSE: We report efficacy of a prospective phase 2 trial (NCT00450411) of salvage low-dose-rate (LDR) prostate brachytherapy (BT) for local failure (LF) after prior external beam radiation therapy (EBRT) with minimum 5-years' follow-up. METHODS AND MATERIALS: Eligible patients had low/intermediate risk prostate cancer (PCa) before EBRT and biopsy-proven LF >30 months after EBRT, with prostate-specific antigen <10 ng/mL and no regional/distant disease. The primary endpoint, late gastrointestinal and genitourinary adverse events (Common Terminology Criteria for Adverse Events v3.0) grade ≥3 were 14%. With minimum 5-year follow-up after salvage BT, secondary clinical outcomes including disease-free survival (DFS; includes death from any cause), disease-specific survival, and overall survival (OS) were estimated using the Kaplan-Meier method and modelled using Cox proportional hazards regression. Local tumor progression (ie, LF), distant failure (DF), and biochemical failure (BF) were estimated using cumulative incidence. Time to LF, DF, and BF were modeled by cause-specific Cox proportional hazards regression. RESULTS: From May 2007 to January 2014, 20 centers registered 100 patients (92 analyzable). Median follow-up is 6.7 years (range, 0.3-11.2); median age 70 years (range, 55-82); median prior EBRT dose 74 Gy [interquartile range (IQR):70 - 76] at a median of 85 months prior (IQR 60-119 months). Androgen deprivation was combined with salvage BT in 16%. Ten-year OS is 70% [95% confidence interval (CI) 58% - 83%]. Nineteen patients died (5 PCa, 10 other, 4 unknown). Ten-year failure rates are local 5% (95% CI, 1-11), distant 19% (95% CI, 10-29), and biochemical 46% (95% CI, 34-57). DFS is 61% at 5 years and 33% at 10 years. No baseline characteristic was significantly associated with any clinical outcome. CONCLUSIONS: This is the first prospective multicenter trial reporting outcomes of salvage LDR BT for LF after EBRT. Five-year freedom from BF is 68%, comparable to other salvage modalities. Although further LF is rare (5%), BF climbs to 46% by 10 years.


Assuntos
Braquiterapia , Neoplasias da Próstata , Idoso , Idoso de 80 Anos ou mais , Antagonistas de Androgênios/uso terapêutico , Braquiterapia/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Próstata/patologia , Antígeno Prostático Específico , Neoplasias da Próstata/patologia , Estudos Retrospectivos , Terapia de Salvação
14.
Biochemistry ; 49(47): 10179-86, 2010 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-20973506

RESUMO

DNA polymerases use either a bulky active site residue or a backbone segment to select against ribonucleotides in order to faithfully replicate cellular genomes. Here, we demonstrated that an active site mutation (Y12A) within Sulfolobus solfataricus DNA polymerase IV (Dpo4) caused an average increase of 220-fold in matched ribonucleotide incorporation efficiency and an average decrease of 9-fold in correct deoxyribonucleotide incorporation efficiency, leading to an average reduction of 2000-fold in sugar selectivity. Thus, the bulky side chain of Tyr12 is important for both ribonucleotide discrimination and efficient deoxyribonucleotide incorporation. Other than synthesizing DNA as the wild-type Dpo4, the Y12A Dpo4 mutant incorporated more than 20 consecutive ribonucleotides into primer/template (DNA/DNA) duplexes, suggesting that this mutant protein possesses both a DNA-dependent DNA polymerase activity and a DNA-dependent RNA polymerase activity. Moreover, the binary and ternary crystal structures of Dpo4 have revealed that this DNA lesion bypass polymerase can bind up to eight base pairs of double-stranded DNA which is entirely in B-type. Thus, the DNA binding cleft of Dpo4 is flexible and can accommodate both A- and B-type oligodeoxyribonucleotide duplexes as well as damaged DNA.


Assuntos
DNA Polimerase beta/metabolismo , Desoxirribonucleotídeos/metabolismo , Domínio Catalítico/genética , DNA Polimerase beta/genética , Mutação , Especificidade por Substrato , Sulfolobus solfataricus/enzimologia
15.
Pract Radiat Oncol ; 10(3): 186-194, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31978591

RESUMO

PURPOSE: Previously a phase III trial of a hydrogel rectal spacer during prostate radiation therapy found decreased toxicity and a clinically significant improvement in bowel quality of life (QOL) at 3 years by the Expanded Prostate Cancer Index. We performed a secondary analysis to identify men less likely to benefit. METHODS AND MATERIALS: Clinical and dosimetric data for the 222 patients enrolled on the SpaceOAR phase III trial were analyzed. The volume of rectum treated to 70 Gy (V70) and the quantitative analysis of normal tissue effects in the clinic (QUANTEC) rectal dose goals were used as surrogates for clinical benefit and plan quality. Mean bowel QOL was assessed at 15 and 36 months posttreatment and the likelihood of 1× (5 points) or 2× (10 points) minimally important difference changes were assessed. RESULTS: Rectal V70 was correlated with physician scored toxicity (P = .033) and was used as a surrogate for plan quality. There was no correlation between prostate volume and rectal V70 (r = 0.077). Rectal V70 pre- and post-hydrogel was 13% and 3% for the smallest prostates (<40 mL) and 12% and 2% for the largest (>80 mL). The relative reduction in rectal V70 of 78% did not vary by prespacer V70, but the absolute reduction was greater for a higher V70. All spacer plans met the 5 QUANTEC rectal dose constraints, although 92% of control plans met all constraints. At 3 years, those not meeting all QUANTEC goals had a 15.0-point (standard deviation 15.1) decline, control patients meeting QUANTEC goals had a 4.0-point (9.5) decline, and spacer had >0.5 (7.6; P < .01). Previous surgery was not correlated with QOL (P = .8). Across prognostic groups, including age, body mass index, previous surgery, target volume, or quality of radiation plans, there was no statistically significant heterogeneity in the relative benefit of spacer in decreasing the risk of 1× or 2× the minimally important difference declines. CONCLUSIONS: There was little heterogeneity in the likelihood of spacer reducing the risk of declines in bowel QOL across clinical and dosimetric variables. Even for the >95% of plans meeting QUANTEC rectal criteria, hydrogel spacer provided potentially meaningful benefits.


Assuntos
Próstata/cirurgia , Neoplasias da Próstata/cirurgia , Reto/cirurgia , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Próstata/efeitos da radiação , Neoplasias da Próstata/radioterapia , Reto/efeitos da radiação
16.
Can Urol Assoc J ; 13(12): 406-411, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31364974

RESUMO

INTRODUCTION: Asymptomatic microscopic hematuria (AMH) is defined in the Canadian Urological Association (CUA) guideline as >2 red blood cells (RBCs) per high-powered field (HPF). Our objective was to evaluate guideline adherence for AMH at our center. Secondarily, we aimed to identify areas of the guideline that can be optimized. METHODS: We retrospectively reviewed 875 consecutive adults referred to two urologists for hematuria between June 2010 and June 2016. Patient characteristics, risk factors, and outcomes were added to an encrypted Research Electronic Data Capture (REDCap) database. Evaluation of microscopic hematuria reporting was performed by analyzing 681 urine samples reported as 1-5 RBC/HPF. Healthcare costs were obtained from Alberta Health Services (AHS), Data Integration and Management Repository (DIMR), and Alberta Society of Radiologists (ASR). RESULTS: Of the 875 patients referred with hematuria, 400 had AMH. Overall, 96.5% completed evaluation consistent with the CUA guideline. The incidence of pathology requiring surgical intervention was 21/400 (5%) with a 0.8% rate (3/400) of urothelial cell carcinoma (UCC) (non-invasive, low-grade). No malignancy was found in non-smokers with normal cytology, normal imaging and <50 RBC/HPF; 44% had AMH in the 1-5 RBCs/HPF range. Only 41% (279/681) of urine samples categorized as 1-5 RBCs/ HPF had guideline-defined microscopic hematuria. By changing local microscopic hematuria reporting to differentiate 1-2 and 3-5 RBCs/HPF, we estimate $745 000 in annual savings. CONCLUSIONS: At our center, CUA AMH guideline adherence is high. We did not find malignancy in non-smokers with normal cytology, imaging and <50 RBC/HPF. We identified and changed regional microscopic hematuria reporting to fit the CUA definition, eliminating unnecessary investigations and healthcare costs.

17.
Pancreas ; 48(3): 356-362, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30768573

RESUMO

OBJECTIVES: Elevated pancreastatin (PST) levels have been shown to be associated with poor prognosis in small bowel neuroendocrine tumors (NETs). We hypothesized that plasma PST levels that remain elevated following surgical cytoreduction portend a poor prognosis in well-differentiated small bowel NETs. METHODS: Patients diagnosed with small bowel NETs who underwent surgical cytoreduction at our institution were identified. Demographics, histopathologic characteristics, and biochemical data were collected. Only patients who had serial preoperative PST (PreopPST) and postoperative PST (PostopPST) levels were included in this study. Patients were sorted into groups by PST level to assess their response to surgical cytoreduction (group 1, PreopPST/PostopPST normal; group 2, PreopPST elevated/PostopPST normal; group 3, PreopPST/PostopPST elevated). Survival rates were calculated from the date of surgery. RESULTS: PreopPST and PostopPST levels were collected from 300 patients. Patients in groups 1 (n = 74) and 2 (n = 81) had a significant survival advantage compared with patients in group 3 (n = 145) (P < 0.0001). Kaplan-Meier 5- and 10-year survival rates were as follows: group 1: 93% and 82%; group 2: 91% and 65%; and group 3: 58% and 34%, respectively. CONCLUSIONS: Serial monitoring of plasma PST is useful in predicting long-term survival following surgical cytoreduction and can be helpful to identify patients who have a poor prognosis.


Assuntos
Biomarcadores Tumorais/sangue , Cromogranina A/sangue , Procedimentos Cirúrgicos de Citorredução/métodos , Intestino Delgado/cirurgia , Tumores Neuroendócrinos/cirurgia , Adulto , Idoso , Feminino , Humanos , Intestino Delgado/patologia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/diagnóstico , Prognóstico , Resultado do Tratamento , Adulto Jovem
18.
J Gastrointest Oncol ; 10(5): 928-934, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31602331

RESUMO

BACKGROUND: Midgut neuroendocrine tumor (NET) patients are often diagnosed at advanced stages with extensive mesenteric nodal and hepatic metastasis. The only potentially curative treatment is surgical tumor eradication. Despite an aggressive resection, macro and microscopic residual disease still may remain in the resection bed. We hypothesize that the application of 5-fluorouracil (5-FU) within the tumor bed will help eliminate microscopic residual disease. METHODS: Records of 189 patients who underwent extensive cytoreductive surgeries during 2003-2012 for advanced, midgut NETs with extensive mesenteric lymphadenopathy were reviewed. Eighty-six patients (46%) who had 5-FU saturated gel foam strips secured into their mesenteric resection sites served as the study group and a matching 103 patients (54%) who did not have such an intra-operative chemotherapy served as controls. Survival from the time of diagnosis and post-operative complications between the two groups were compared. RESULTS: Mortality rates at 30, 60 and 90 days post-operatively were 4%, 0%, 0% versus 2%, 0%, 2% for study and control groups, respectively. Major complications (Grades III & IV) at the same intervals were 0, 0, 1 versus 2, 3, 2 for study and control groups, respectively. Median survival was 236 months versus 148 months for the study and control groups, respectively 24 (P=0.15). CONCLUSIONS: Intraoperative tumor resection bed chemotherapy is a safe adjuvant without discernible toxicity. This procedure may provide survival benefits to midgut NET patients with extensive mesenteric lymphadenopathy undergoing extensive cytoreductive surgery. Further study in prospective trials must be conducted to determine definitive benefit to the NET patient.

19.
Gland Surg ; 8(6): 609-617, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32042667

RESUMO

BACKGROUND: In breast cancer treatment, marking the tumor bed is an important aspect of the surgical component of therapy. Clear delineation of the tumor bed allows radiation oncologists a defined target for planning and delivering postoperative radiation therapy (XRT). Tumor bed marking also allows radiographic follow-up of the tumor bed on subsequent breast imaging. The aim of this assessment is to evaluate the ease and feasibility of utilizing a tumor bed filament marker (VeraFormÒ, Videra Surgical inc., USA) as a marker in post-operative benign surgical sites and malignant breast surgical tumor beds in breast cancer surgery. METHODS: The filament marker is a novel radiopaque surgical filament that in lieu of clips and other markers is implanted in the surgical tumor bed during breast surgery. Following development of the filament marker, the researchers used breast phantoms and radiographic images to develop a series of geometric patterns of placement options that optimize comprehensive multi-plane radiographic interpretation of the exact tumor bed or surgical margin. Three breast surgeons at 3 separate institutions then used this filament as a continuous multi-plane marker in 20 patients during breast conservation surgery. In these patients, the filament marker was thus used to mark the tumor bed (breast cancer surgery) or surgical site (benign breast disease) instead of the more traditional devices such as clips or other metallic open framework devices. We then assessed 2 important factors related to this device; (I) the ease, feasibility, and accuracy of in vivo placement with oncoplastic and non-oncoplastic breast conservation surgery techniques; (II) the radiographic footprint this device left on standard imaging protocols of post-operative mammogram (MMG), computed tomography (CT) scan, breast magnetic resonance imaging (MRI) examinations, and ultrasounds (USs) for both routine follow-up imaging and for standard radiation planning. RESULTS: There were no adverse events reported with the use of this device. The cases were then reviewed by a multidisciplinary team that included the original surgeon, a breast radiologist, and radiation oncologist. Their unanimous evaluation was that the filament marker clearly delineated all sides and planes of the tumor bed (cancer surgery) or surgical site (benign disease). Regardless of surgical technique utilized, this information provided precise 3D guidance for radiation planning and delivery as well as radiographic follow-up. The surgeons involved reported that delineating the bed with the filament marker was a quick and easy procedure and did not interfere with performing the planned surgical technique. Radiologists, surgeons, and radiation oncologists found that the filament marker was not only radiographically opaque on CT and MMG, but also caused no significant artifact on CT, MRI, US, or MMG. CONCLUSIONS: The continuous multi-plane filament marker is a new device that fulfills the heretofore unmet need for safe and improved tumor bed and tissue site marking. It is an easy to place, non-palpable continuous multi-plane radiographic opaque tissue marker that seems to better delineate the tumor bed, regardless of type of breast surgery performed, while providing a more accurate 3D image for radiation planning and radiographic follow-up on MMG MRI, CT and US.

20.
Int J Radiat Oncol Biol Phys ; 103(2): 335-343, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30312717

RESUMO

PURPOSE: Only retrospective data are available for low-dose-rate (LDR) salvage prostate brachytherapy for local recurrence after external beam radiation therapy (EBRT). The primary objective of this prospective phase 2 trial (NCT00450411) was to evaluate late gastrointestinal and genitourinary adverse events (AEs) after salvage LDR brachytherapy. METHODS AND MATERIALS: Eligible patients had low- or intermediate-risk prostate cancer before EBRT and biopsy-proven recurrence >30 months after EBRT, with prostate-specific antigen levels <10 ng/mL and no regional/distant disease. The primary endpoint was grade 3 or higher late treatment-related gastrointestinal or genitourinary AEs occurring 9 to 24 months after brachytherapy. These AEs were projected to be ≤10%, with ≥20% considered unacceptable. All events were graded with National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. Multivariate analyses investigated associations of pretreatment or treatment variables with AEs. RESULTS: One hundred patients from 20 centers were registered from May 2007 to January 2014. The 92 analyzable patients had a median follow-up of 54 months (range, 4-97) and a median age of 70 years (interquartile range [IQR], 65-74). The initial Gleason score was 7 in 48% of patients. The median dose of EBRT was 74 Gy (IQR, 70-76) at a median interval of 85 months previously (IQR, 60-119). Only 16% had androgen deprivation at study entry. Twelve patients (14%) had late grade 3 gastrointestinal/genitourinary AEs, with no treatment-related grade 4 or 5 AEs. No pretreatment variable predicted late AEs, including prior EBRT dose and elapsed interval. Higher V100 (percentage of prostate enclosed by prescription isodose) predicted both occurrence of late AEs (odds ratio, 1.24; 95% confidence interval, 1.02-1.52; P = .03) and earlier time to first occurrence (hazard ratio, 1.18; 95% CI, 1.03-1.34; P = .02). CONCLUSIONS: This prospective multicenter trial reports outcomes of salvage LDR brachytherapy for post-EBRT recurrence. The rate of late grade 3 AEs did not exceed the unacceptable threshold. The only factor predictive of late AEs was implant dosimetry reflected by V100. Efficacy outcomes will be reported at a minimum of 5-year follow-up.


Assuntos
Braquiterapia/efeitos adversos , Braquiterapia/métodos , Trato Gastrointestinal/efeitos da radiação , Neoplasias da Próstata/radioterapia , Terapia de Salvação/efeitos adversos , Terapia de Salvação/métodos , Idoso , Biópsia , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Gradação de Tumores , Recidiva Local de Neoplasia/radioterapia , Estudos Prospectivos , Próstata , Antígeno Prostático Específico , Dosagem Radioterapêutica , Radioterapia Guiada por Imagem/efeitos adversos , Radioterapia Guiada por Imagem/métodos , Resultado do Tratamento , Ultrassonografia
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