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1.
United European Gastroenterol J ; 11(10): 985-997, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38018771

RESUMO

BACKGROUND AND AIMS: We studied the impact of Portal hypertension (PHT) on ascites occurrence and on radiotherapy outcome in cirrhotic patients with hepatocellular carcinoma (HCC). METHOD: All cirrhotic patients that received radiotherapy for HCC between 2012 and 2022 were included. Portal hypertension-Score was built using univariate analysis with the presence of esophageal varices (EV), platelet count, history of acute variceal bleeding (AVB) and spleen size. Time-to-events data were estimated using Kaplan-Meier method with log-rank and Cox-models. RESULTS: 60 patients were included (female 27%, age 67 years-old, Child-Pugh A 82%, alcoholic/non-alcoholic steatohepatitis/hepatitis C virus 55/40/32%). 38% and 15% presented history of ascites and AVB respectively, 25% had large EV, 53.5% presented PHT score ≥ 5. 92% were BCLC-0/A, median tumor size was 30 mm. At 6 months, ascites incidence was 19% and precluded access to further HCC treatment for all patients with HCC recurrence. All PHT parameters included in the score and PHT score ≥ 5 (hazard ratio (HR) = 14.07, p = 0.01) were associated with ascites occurrence. Transplantation free survival and recurrence free survival at 1 year were 56% and 47% respectively. Albi grade 3 (HR = 3.01; p = 0.04) was independently associated with Transplantation free survival. CONCLUSION: Radiotherapy should be cautiously performed in patients with PHT score ≥ 5 because of ascites occurrence risk precluding access to further HCC treatments.


Assuntos
Carcinoma Hepatocelular , Varizes Esofágicas e Gástricas , Hipertensão Portal , Hipertensão , Neoplasias Hepáticas , Humanos , Feminino , Idoso , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/radioterapia , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/radioterapia , Varizes Esofágicas e Gástricas/diagnóstico , Varizes Esofágicas e Gástricas/epidemiologia , Varizes Esofágicas e Gástricas/etiologia , Ascite/etiologia , Ascite/complicações , Resultado do Tratamento , Hemorragia Gastrointestinal/complicações , Hipertensão Portal/etiologia , Cirrose Hepática/complicações , Hipertensão/complicações
2.
Eur Urol Oncol ; 6(4): 399-405, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36754722

RESUMO

BACKGROUND: There is no consensus on the best local salvage treatment for prostate cancer recurrence after primary external beam radiotherapy. Prospective data on stereotactic body radiation therapy (SBRT) are very scarce. OBJECTIVE: To determine the optimal dose regimen for salvage SBRT. DESIGN, SETTING, AND PARTICIPANTS: The present report concerns the phase 1 part of the GETUG-AFU 31 multicenter open-label study. The main inclusion criteria were histologically proven biochemical recurrence, clinical stage T1-T2 upon relapse, multiparametric magnetic resonance imaging data, prostate-specific antigen (PSA) level ≤10 ng/ml prior to salvage SBRT, PSA doubling time >10 mo, and an International Prostate Symptom Score of ≤12. INTERVENTION: Five or six fractions of 6 Gy were delivered using focal SBRT. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Dose-limiting toxicity (DLT) was defined as grade ≥3 gastrointestinal or genitourinary tract toxicity, or any grade 4 toxicity (according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.03) occurring in the first 18 wk following treatment initiation. A time-to-event continual reassessment method was used to select the dose regimen. RESULTS AND LIMITATIONS: Twenty-one patients were treated (median [interquartile range] age: 76.8 yr [72.2-80.8]), including 12 at 6 × 6 dose level. No DLT was observed. The acute grade 2 genitourinary tract toxicity rate was 19%. With a median follow-up of 12.3 mo, the estimated cumulative incidence of late grade 2 genitourinary toxicity was 41.2% (95% confidence interval: 18.1-63.1%). No grade >2 genitourinary toxicity and no grade ≥2 gastrointestinal toxicity were reported. All treated patients were alive and relapse free at the last follow-up. CONCLUSIONS: A 6 × 6 Gy dose regimen was selected for our phase 2 study of salvage SBRT. With a short follow-up period, the level of toxicity appears to be acceptable. PATIENT SUMMARY: There is no consensus on the best local treatment for patients with local relapse after radiotherapy for prostate cancer. Prospective data are very scarce. Our early phase trial allowed us to recommend six fractions of 6 Gy using high-precision radiotherapy for further studies.


Assuntos
Neoplasias da Próstata , Radiocirurgia , Masculino , Humanos , Idoso , Radiocirurgia/efeitos adversos , Radiocirurgia/métodos , Antígeno Prostático Específico , Recidiva Local de Neoplasia/radioterapia , Recidiva Local de Neoplasia/cirurgia , Recidiva Local de Neoplasia/patologia , Estudos Prospectivos , Neoplasias da Próstata/patologia
3.
Sci Rep ; 13(1): 2033, 2023 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-36739457

RESUMO

In a large retrospective study, we assessed the putative use of circulating microvesicles (MVs), as innovative biomarkers of radiation toxicity in a cohort of 208 patients with prostate adenocarcinoma overexposed to radiation. The level of platelet (P)-, monocyte (M)- and endothelial (E)-derived MVs were assessed by flow cytometry. Rectal bleeding toxicity scores were collected at the time of blood sampling and during the routine follow-up and were tested for association with MVs using a multivariate logistic regression. MVs dosimetric correlation was investigated using dose volume histograms information available for a subset of 36 patients. The number of PMVs was significantly increased in patients with highest toxicity grades compared to lower grades. Risk prediction analysis revealed that increased numbers of PMVs, and an increased amount of MMVs relative to EMVs, were associated with worst rectal bleeding grade compared to the time of blood sampling. Moreover, a significant correlation was found between PMV and MMV numbers, with the range of doses up to the median exposure (40 Gy) of bladder/rectum and anterior rectal wall, respectively. MVs could be considered as new biomarkers to improve the identification of patients with high toxicity grade and may be instrumental for the prognosis of radiation therapy complications.


Assuntos
Gastrite , Proctite , Neoplasias da Próstata , Lesões por Radiação , Reto , Humanos , Masculino , Proctite/etiologia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/radioterapia , Lesões por Radiação/patologia , Dosagem Radioterapêutica , Reto/patologia , Reto/efeitos da radiação , Estudos Retrospectivos
4.
Stem Cell Res Ther ; 14(1): 5, 2023 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-36627674

RESUMO

BACKGROUND: Cellular therapy seems to be an innovative therapeutic alternative for which mesenchymal stem cells (MSCs) have been shown to be effective for interstitial and hemorrhagic cystitis. However, the action of MSCs on chronic radiation cystitis (CRC) remains to be demonstrated. The aim of this study was to set up a rat model of CRC and to evaluate the efficacy of MSCs and their mode of action. METHODS: CRC was induced by single-dose localized irradiation of the whole bladder using two beams guided by tomography in female Sprague-Dawley rat. A dose range of 20-80 Gy with follow-up 3-12 months after irradiation was used to characterize the dose effect and the kinetics of radiation cystitis in rats. For the treatment, the dose of 40 Gy was retained, and in order to potentiate the effect of the MSCs, MSCs were isolated from adipose tissue. After expansion, they were injected intravenously during the pre-chronic phase. Three injections of 5 million MSCs were administered every fortnight. Follow-up was performed for 12 months after irradiation. RESULTS: We observed that the intensity and frequency of hematuria are proportional to the irradiation dose, with a threshold at 40 Gy and the appearance of bleeding from 100 days post-irradiation. The MSCs reduced vascular damage as well as damage to the bladder epithelium. CONCLUSIONS: These results are in favor of MSCs acting to limit progression of the chronic phase of radiation cystitis. MSC treatment may afford real hope for all patients suffering from chronic radiation cystitis resistant to conventional treatments.


Assuntos
Cistite , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Lesões por Radiação , Ratos , Feminino , Animais , Ratos Sprague-Dawley , Urotélio , Cistite/terapia , Bexiga Urinária , Lesões por Radiação/terapia , Transplante de Células-Tronco Mesenquimais/métodos
5.
Laryngoscope ; 133(3): 607-614, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35638238

RESUMO

OBJECTIVES: Head & Neck Paragangliomas have been historically relying on surgery mostly, with worsened quality of life and major sequelae. Conventional external radiation therapy seems to offer an equivalent control rate with a low toxicity profile. The aim of this study was to assess the safety and efficiency of intensity-modulated radiation therapy in Head & Neck paragangliomas. METHODS: This is a retrospective monocentric study conducted in a referral center, including all patients treated with IMRT, whether as an exclusive or post-operative treatment for a tympanic and jugular, carotid, or vagal paraganglioma. Data collection was performed through the manuscript and computerized medical files, including consultation, operative, imaging, pathological analyses, delineation, and treatment planning reports. Success was defined as the complete or partial regression or stabilization without progression, or relapse in accordance with the RECIST criteria. Acute toxicities and long-term sequelae were assessed. RESULTS: Our cohort included 39 patients included between 2011 and 2021: 18 patients treated for a TJ PG (45.9%), 11 patients for a carotid PG (28.4%), and 9 for a vagal PG (23.1%). Twenty-nine patients had IMRT as an exclusive treatment (74.4%), whereas 10 patients had a post-operative complementary treatment (25.6%). Median follow-up in our cohort was 2318 days (average = 2200 days, 237-5690, sd = 1281.9). Among 39 patients, 37 were successfully controlled with IMRT (94.8%), and the toxicity profile was low without any major toxicity. CONCLUSION: IMRT seems an ideal treatment, whether exclusive or post-operative for Head & Neck paragangliomas. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:607-614, 2023.


Assuntos
Neoplasias de Cabeça e Pescoço , Paraganglioma , Radioterapia de Intensidade Modulada , Humanos , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos , Qualidade de Vida , Neoplasias de Cabeça e Pescoço/radioterapia , Recidiva Local de Neoplasia , Paraganglioma/radioterapia , Paraganglioma/patologia
6.
Biology (Basel) ; 11(7)2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-36101353

RESUMO

Cystitis is a bladder disease with a high rate of prevalence in the world population. This report focuses on Interstitial Cystitis (IC), Hemorrhagic Cystitis (HC) and Chronic Radiation Cystitis. These pathologies have different etiologies, but they share common symptoms, for instance, pain, bleeding, and a contracted bladder. Overall, treatments are quite similar for abacterial cystitis, and include bladder epithelium protective or anti-inflammatory agents, alleviating pain and reducing bleeding. This review summarizes the mechanisms that the pathologies have in common, for instance, bladder dysfunction and inflammation. Conversely, some mechanisms have been described as present in only one pathology, such as neural regulation. Based on these specificities, we propose identifying a mechanism that could be common to all the above-mentioned pathologies.

7.
Thyroid ; 32(10): 1271-1276, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35880417

RESUMO

Background: Nuclear protein in testis (NUT) carcinomas (NC) are a rare, highly aggressive, subset of squamous cell carcinomas, characterized by a translocation involving the NUTM1 gene. Thyroid location of NUT carcinomas has rarely been described. Methods: We report here two cases of thyroid NC with NSD3::NUTM1 translocation. Results: The first case presented as a very aggressive undifferentiated thyroid carcinoma in a 38-year-old man who died 21 months after the diagnosis. The second case was diagnosed after multiple lymphadenopathy recurrences mainly in the neck in a 37-year-old woman 7 years after total thyroidectomy for papillary thyroid carcinoma with a classic and a solid/trabecular component. Conclusions: Our case reports highlight the challenges in diagnosing these exceptional carcinomas. The therapeutic impact of the administration of pharmacological compounds with epigenetic action, in line with the physiopathology of these carcinomas, is also discussed.


Assuntos
Carcinoma , Proteínas Nucleares , Masculino , Feminino , Humanos , Adulto , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Neoplasias/genética , Glândula Tireoide/patologia , Testículo/metabolismo , Testículo/patologia , Análise de Sequência de RNA , Carcinoma/patologia
8.
Crit Rev Oncol Hematol ; 173: 103661, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35341986

RESUMO

Stereotactic body radiotherapy (SBRT) has become treatment option for localized prostate cancer but the evidence base remains incomplete. Several clinical studies, both prospective and retrospective, have been published. However, treatment techniques, target volumes and dose constraints lack consistency between studies. Based on the current available literature, the French Genito-Urinary Group (GETUG) suggests that.


Assuntos
Neoplasias da Próstata , Radiocirurgia , Humanos , Masculino , Estudos Prospectivos , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Radiocirurgia/métodos , Estudos Retrospectivos
9.
Dig Liver Dis ; 54(10): 1428-1436, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35120842

RESUMO

BACKGROUND: prognostic biomarkers could be useful to better select patients with borderline resectable (BR) or locally advanced (LA) pancreatic adenocarcinoma (PA) for chemoradiotherapy (CRT) and/or secondary resection. AIMS: The main objective of this work was to study characteristics, received treatments and prognostic of patients with BR or LA PA according to their baseline circulating tumor DNA status and, for secondary objective, neutrophil-to-lymphocyte Ratio (NLR). METHODS: ctDNA status at baseline was determined using Next Generation Sequencing in a consecutive monocentric cohort of patients with a BR or LA PA. RESULTS: 69 patients were included, 31 with BR PA and 38 with LA PA. 14 (20.3%) patients had baseline positive ctDNA. Five (7.8%) patients had NLR> 5. Patients with positive ctDNA had 3.7 months shorter progression free survival (p = 0.006). Patients with positive ctDNA had earlier progression after the beginning of CRT (4.4 vs 7.1 months; p = 0.068) and shorter relapse free survival after secondary resection (9.2 vs 22.9 months; p = 0.016). CONCLUSIONS: positive ctDNA at baseline was associated with a worse prognosis in patients with BR or LA PA. These data are exploratory and must be confirmed in further prospective trials.


Assuntos
Adenocarcinoma , DNA Tumoral Circulante , Neoplasias Pancreáticas , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/terapia , Biomarcadores , Biomarcadores Tumorais/genética , DNA Tumoral Circulante/genética , Humanos , Recidiva Local de Neoplasia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/terapia , Prognóstico , Neoplasias Pancreáticas
10.
Int J Mol Sci ; 23(3)2022 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-35163758

RESUMO

Chronic radiation cystitis (CRC) is a consequence of pelvic radiotherapy and affects 5-10% of patients. The pathology of CRC is without curative treatment and is characterized by incontinence, pelvic pain and hematuria, which severely degrades patients' quality of life. Current management strategies rely primarily on symptomatic measures and have certain limitations. Thanks to a better understanding of the pathophysiology of radiation cystitis, studies targeting key manifestations such as inflammation, neovascularization and cell atrophy have emerged and are promising avenues for future treatment. However, the mechanisms of CRC are still better described in animal models than in human models. Preclinical studies conducted to elucidate the pathophysiology of CRC use distinct models and are most often limited to specific processes, such as fibrosis, vascular damage and inflammation. This review presents a synthesis of experimental studies aimed at improving our understanding of the molecular mechanisms at play and identifying key processes in CRC.


Assuntos
Cistite/etiologia , Lesões por Radiação/metabolismo , Animais , Cistite/metabolismo , Cistite/patologia , Modelos Animais de Doenças , Fibrose , Redes Reguladoras de Genes , Humanos , Qualidade de Vida , Lesões por Radiação/complicações , Lesões por Radiação/patologia
11.
Therapie ; 77(3): 265-271, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34895755

RESUMO

The prevalence and incidence of cardiac pro-arrhythmic disorders are often influenced by sex due to specific effects on the QT interval. Androgens shorten QT, which may be protective against acquired long QT syndromes and their related arrhythmias in men such as torsade de pointes (TdP). On the other hand, androgens can potentiate Brugada and early repolarization syndromes, which are most prevalent in men. In this case series, we highlight four male patients with aborted SCD in the setting of abnormal testosterone status; two patients with TdP in a setting of testosterone deprivation (of which one drug-induced) and 2 patients with ventricular fibrillation associated with exogenous androgenic booster (Tribulus terrestris) intake. From this case series, we review the current available literature of the effects of androgen as a double-edged sword on the QTc interval and emphasize the importance of QTc monitoring in this subset of patients.


Assuntos
Síndrome do QT Longo , Torsades de Pointes , Androgênios/efeitos adversos , Proteínas de Ligação a DNA , Humanos , Síndrome do QT Longo/induzido quimicamente , Masculino , Testosterona/efeitos adversos , Torsades de Pointes/induzido quimicamente
12.
J Chem Phys ; 154(16): 164506, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33940831

RESUMO

In fluids, the compressibility and related thermodynamic properties can be obtained from Kirkwood-Buff integrals (KBIs), i.e., infinite volume integrals over the radial distribution function (RDF). KBI theory has never been applied to crystals because the KBIs diverge when computed in the standard way as running integrals. Here, we show that KBI theory can be applied to solids without divergence, provided that the recently developed finite volume KBI method is used. In order to accelerate the integral convergence as a function of system size, we introduce a physically motivated convolution of the RDF. When using the convoluted RDF and an extrapolation of the finite-volume KBI, the zero-temperature KBI converges very fast to the exact value. We apply the theory to solid argon at finite temperatures. The RDF is computed with a Lennard-Jones potential using Monte Carlo and molecular dynamics simulations, and the isothermal compressibility κT is obtained from the KBI. The variation of κT with temperature agrees very well with experiment. The absolute value of κT is, however, underestimated by 40%-50%, which is attributed to finite size effects of the RDF obtained from molecular simulation. The error can be corrected by a single scaling factor that can be easily calculated at zero temperature. By extending Kirkwood-Buff solution theory to solids, this work lays a new framework for the thermodynamic modeling of complex structures, alloys, and solid solutions.

13.
Radiat Oncol ; 16(1): 45, 2021 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-33639959

RESUMO

PURPOSE: To compare linac-based mono-isocentric radiosurgery with Brainlab Elements Multiple Brain Mets (MBM) SRS and the Gamma Knife using a specific statistical method and to analyze the dosimetric impact of the target volume geometric characteristics. A dose fall-off analysis allowed to evaluate the Gradient Index relevancy for the dose spillage characterization. MATERIAL AND METHODS: Treatments were planned on twenty patients with three to nine brain metastases with MBM 2.0 and GammaPlan 11.0. Ninety-five metastases ranging from 0.02 to 9.61 cc were included. Paddick Index (PI), Gradient Index (GI), dose fall-off, volume of healthy brain receiving more than 12 Gy (V12Gy) and DVH were used for the plan comparison according to target volume, major axis diameter and Sphericity Index (SI). The multivariate regression approach allowed to analyze the impact of each geometric characteristic keeping all the others unchanged. A parallel study was led to evaluate the impact of the isodose line (IDL) prescription on the MBM plan quality. RESULTS: For mono-isocentric linac-based radiosurgery, the IDL around 70-75% was the best compromise found. For both techniques, the GI and the dose fall-off decreased with the target volume. In comparison, PI was slightly improved with MBM for targets < 1 cc or SI > 0.78. GI was improved with GP for targets < 2.5 cc. The V12Gy was higher with MBM for lesions > 0.4 cc or SI < 0.84 and exceeded 10 cc for targets > 5 cc against 6.5 cc with GP. The presence of OAR close to the PTV had no impact on the dose fall off values. The dose fall-off was higher for volumes < 3.8 cc with GP which had the sharpest dose fall-off in the infero-superior direction up to 30%/mm. The mean beam-on time was 94 min with GP against 13 min with MBM. CONCLUSIONS: The dose fall-off and the V12Gy were more relevant indicators than the GI for the low dose spillage assessment. Both evaluated techniques have comparable plan qualities with a slightly improved selectivity with MBM for smaller lesions but with a healthy tissues sparing slightly favorable to GP at the expense of a considerably longer irradiation time. However, a higher healthy tissue exposure must be considered for large volumes in MBM plans.


Assuntos
Neoplasias Encefálicas/radioterapia , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Encéfalo/efeitos da radiação , Neoplasias Encefálicas/patologia , Humanos , Órgãos em Risco/efeitos da radiação , Radiometria , Dosagem Radioterapêutica
14.
J Chem Phys ; 153(20): 204502, 2020 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-33261471

RESUMO

The adsorption of carbon monoxide and nitrogen molecules at the surface of four forms of solid water is investigated by means of grand canonical Monte Carlo simulations. The trapping ability of crystalline Ih and low-density amorphous ices, along with clathrate hydrates of structures I and II, is compared at temperatures relevant for astrophysics. It is shown that when considering a gas phase that contains mixtures of carbon monoxide and nitrogen, the trapping of carbon monoxide is favored with respect to nitrogen at the surface of all solids, irrespective of the temperature. The results of the calculations also indicate that some amounts of molecules can be incorporated in the bulk of the water structures, and the molecular selectivity of the incorporation process is investigated. Again, it is shown that incorporation of carbon monoxide is favored with respect to nitrogen in most of the situations considered here. In addition, the conclusions of the present simulations emphasize the importance of the strength of the interactions between the guest molecules and the water network. They indicate that the accuracy of the corresponding interaction potentials is a key point, especially for simulating clathrate selectivity. This highlights the necessity of having interaction potential models that are transferable to different water environments.

15.
Phys Chem Chem Phys ; 22(42): 24561-24571, 2020 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-33094778

RESUMO

We report a study on adsorption and coadsorption of H2 and D2 in FAU, MFI and CHA pure silica zeolites having different pore sizes and shapes. Adsorption capacities, selectivities, enthalpies and entropies are determined by combining experiments and GCMC simulations. We show that the force fields available in the literature cannot predict the adsorption equilibria below 77 K with sufficient accuracy. Here we propose a new force field adjusted by using our experimental data obtained for the pure silica MFI zeolite at 65 K and 77 K. With this new force field, it is possible to predict the adsorption and coadsorption equilibria on the three zeolite structures in a temperature range between 47 and 77 K with satisfactory precision. We corroborate that the step appearing on the single adsorption isotherms in CHA is the result of a molecular rearrangement of the adsorbed phase due to the apparition of a new adsorption site characterized by weaker interactions of H2 with the adsorbent. We conclude that the quantum sieving of H2 and D2 not only depends on the pore size but also on the pore shape, in particular, at high loading when the confinement effects become important.

16.
Nanomaterials (Basel) ; 10(4)2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32316368

RESUMO

Kirkwood-Buff (KB) integrals provide a connection between microscopic properties and thermodynamic properties of multicomponent fluids. The estimation of KB integrals using molecular simulations of finite systems requires accounting for finite size effects. In the small system method, properties of finite subvolumes with different sizes embedded in a larger volume can be used to extrapolate to macroscopic thermodynamic properties. KB integrals computed from small subvolumes scale with the inverse size of the system. This scaling was used to find KB integrals in the thermodynamic limit. To reduce numerical inaccuracies that arise from this extrapolation, alternative approaches were considered in this work. Three methods for computing KB integrals in the thermodynamic limit from information of radial distribution functions (RDFs) of finite systems were compared. These methods allowed for the computation of surface effects. KB integrals and surface terms in the thermodynamic limit were computed for Lennard-Jones (LJ) and Weeks-Chandler-Andersen (WCA) fluids. It was found that all three methods converge to the same value. The main differentiating factor was the speed of convergence with system size L. The method that required the smallest size was the one which exploited the scaling of the finite volume KB integral multiplied by L. The relationship between KB integrals and surface effects was studied for a range of densities.

17.
Chem Commun (Camb) ; 56(41): 5564-5566, 2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32342087

RESUMO

Coadsorption experiments reveal an unexpected increase of the D2/H2 selectivity with loading in pure silica chabazite at 47 K. This effect is correlated with the appearance of a step in the adsorption isotherms of H2 and D2. Grand canonical Monte Carlo simulations show that this phenomenon is related to a molecular rearrangement of the adsorbed phase induced by its strong confinement. In the case of a H2 and D2 mixture, this rearrangement favors the adsorption of D2 having a smaller size due to quantum effects.

18.
Dig Liver Dis ; 52(2): 214-220, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31427089

RESUMO

BACKGROUND: Indication for adjuvant chemotherapy in ypN0 rectal cancer patients after chemoradiotherapy (CRT) is debated. The clinical significance of the presence of sterilized lymph nodes (LNS) in ypN0 patients remains to be determined. AIMS: To assess the prognostic value of LNS in ypN0 rectal cancers after neoadjuvant CRT. METHODS: From 2006-2016, 235 patients underwent TME surgery for non-metastatic mid-low rectal cancer after CRT. A lymph node was considered sterilized if there were signs of treatment response (fibrosis, necrosis or mucus) without residual tumor cells. RESULTS: 180 patients (77%) were classified ypN0 and 55 (23%) ypN+. LNS was present in 20 patients (9%). In ypN0 patients, 5-year OS was similar between patients with and without LNS. In contrast, 5-year DFS was significantly lower in ypN0/LNS + patients (58% vs. 78%, p = 0.043) and was similar to those staged ypN+. In multivariate analysis, two factors were independent predictors of DFS: mesorectal grading (OR = 3.14; 95%CI: 1.10-8.34; p = 0.033) and the presence of LNS (OR = 3.93, 95% CI: 1.06-11.81, p = 0.042) CONCLUSION: The presence of LNS in ypN0 rectal cancer after neoadjuvant CRT is associated with an increased risk of recurrence and may be taken into account for the discussion of adjuvant chemotherapy.


Assuntos
Linfonodos/patologia , Recidiva Local de Neoplasia/patologia , Neoplasias Retais/patologia , Neoplasias Retais/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimiorradioterapia Adjuvante , Intervalo Livre de Doença , Feminino , Fluoruracila/administração & dosagem , Humanos , Metástase Linfática/patologia , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Neoplasia Residual , Cuidados Pré-Operatórios , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
19.
Int J Radiat Oncol Biol Phys ; 105(4): 824-833, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31404579

RESUMO

PURPOSE: Defective mismatch repair system (dMMR) has been shown to have a favorable impact on outcome in patients with colorectal cancer treated with surgery or immunotherapy, with adjuvant chemotherapy being discouraged unless there is nodal involvement. Its impact on radiosensitivity is unknown in patients with colorectal cancer. METHODS AND MATERIALS: Patients treated for locally advanced rectal cancer between 2000 and 2016 were studied. Reported points included age, sex, clinical and radiologic tumor stages at diagnosis, modalities of neoadjuvant treatment, posttreatment pathologic staging, tumor regression score, and local, distant relapse-free, and overall survival. An inverse probability of treatment weighting propensity score analysis was performed to evaluate the association of mismatch repair proficiency with surgical and clinical outcomes. RESULTS: Among the 296 patients included, 23 (7.8%) had dMMR. Median follow-up was 43.0 months (interquartile range, 27.9-66.7). Patients with dMMR were significantly younger than the others. After inverse probability of treatment weighting propensity score matching, dMMR patients had higher pathologic downstaging rate (P < .0001), higher tumor regression grade (P = .024), and a longer recurrence-free survival (P < .0001). CONCLUSIONS: dMRR was associated with significant tumor downstaging after neoadjuvant chemoradiation and with increased recurrence-free survival. dMMR patients may have more radiosensitive tumors.


Assuntos
Quimiorradioterapia Adjuvante , Reparo de Erro de Pareamento de DNA/fisiologia , Terapia Neoadjuvante/métodos , Neoplasias Retais/genética , Neoplasias Retais/terapia , Fatores Etários , Idoso , Feminino , Mutação em Linhagem Germinativa , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Intervalo Livre de Progressão , Pontuação de Propensão , Tolerância a Radiação/genética , Neoplasias Retais/mortalidade , Neoplasias Retais/patologia , Estudos Retrospectivos , Fatores Sexuais , Resultado do Tratamento
20.
Cancers (Basel) ; 11(6)2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31248183

RESUMO

(1) Background: To assess the role of postoperative external beam radiotherapy (pEBRT) on locoregional failure (LRF) for patients with locally advanced high-risk non-anaplastic thyroid carcinoma (naTC) at primary event or relapse. (2) Methods: Between 1995 and 2015, postoperative naTC patients with a theoretical indication for EBRT were included based on criteria that were common to American-British-French current guidelines, i.e., pT3-4, pN+, gross or microscopic residual disease. Inverse probability of treatment weighting (IPTW) after multiple imputation was used to reduce selection biases. (3) Results: Of 254 naTC patients, 216 patients underwent pEBRT (106 de novo, 110 at relapse, median dose 60 Gy) and 38 underwent surgery only. pEBRT patients had more gross residual disease, a major prognostic factor (p = 0.027) but less perineural invasion (p = 0.008) or lymphovascular emboli (p = 0.009). pEBRT patients more frequently underwent radioiodine therapy (p = 0.026). The 10-year cumulative incidence of LRF was 56% (95% CI, 32-74%) in operated patients, and 23% (95% CI, 17-30%) in pEBRT patients. After IPTW method, pEBRT reduced the risk of LRF (hazard ratio 0.30; 95% CI [0.18-0.49], p < 0.001), but had no impact on OS. In the pEBRT group, non-Intensity Modulated RadioTherapy (IMRT) plans and interruption of the radiotherapy were associated with poorer survival, while extended versus limited field strategy and dose were not. (4) Conclusions: In naTC patients who have pT3-4, pN+ disease or R1-2 resection, pEBRT improved LRF. Limited-field IMRT is preferred.

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