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1.
World J Surg ; 2024 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-38972979

RESUMEN

BACKGROUND: Follicular thyroid carcinoma (FTC) in adolescents and young adults (AYAs) is rare and data on long-term oncological outcomes are scarce. This study aimed to describe the long-term recurrence and survival rates of AYAs with FTC, and identify risk factors for recurrence. METHODS: This is a retrospective cohort study combining two national databases, including all patients aged 15-39 years, diagnosed with FTC in The Netherlands between 2000 and 2016. Age, sex, tumor size, focality, positive margins, angioinvasion, pT-stage, and pN-stage were included in a Cox proportional hazard model to identify risk factors for recurrence. RESULTS: We included 192 patients. Median age was 31.0 years (IQR 24.7-36.3) and the male to female ratio was 1:4.1. Most patients presented with a minimally invasive FTC (MI-FTC) (95%). Five patients presented with synchronous metastases (2.6%), including two with locoregional metastases (1%) and three with distant metastases (1.6%). During a median follow-up of 12.0 years, three patients developed a recurrence (1.6%), of which one patient developed a local recurrence (33%), and two patients a distant recurrence (67%). Five patients died during follow-up (2.6%). Cause of death was not captured. A Cox proportional hazard model could not be performed due to the low number of recurrences. CONCLUSIONS: FTC in AYAs is generally characterized as a low-risk tumor, as it exhibits a very low recurrence rate, a high overall survival, and it typically presents as MI-FTC without synchronous metastases. These findings underscore the favorable long-term oncological prognosis of FTC in AYAs.

2.
Front Endocrinol (Lausanne) ; 13: 899506, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35600573

RESUMEN

Introduction: Pediatric thyroid carcinoma is a rare malignancy and data on long-term oncological outcomes are sparse. The aim of this study was to describe the long-term oncological outcomes of pediatric papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC) in a national cohort, and to identify risk factors for recurrence. Methods: We conducted a nationwide, retrospective cohort study, in which we combined two national databases. Patients aged <18 years, diagnosed with PTC or FTC in the Netherlands between 2000 and 2016, were included. pT-stage, pN-stage, multifocality and angioinvasion were included in a Cox-regression analysis for the identification of risk factors for recurrence. Results: 133 patients were included: 110 with PTC and 23 with FTC. Patients with PTC most often presented with pT2 tumors (24%) and pN1b (45%). During a median follow-up of 11.3 years, 21 patients with PTC developed a recurrence (19%). Nineteen recurrences were regional (91%) and 2 were pulmonary (9%). No risk factors for recurrence could be determined. One patient who developed pulmonary recurrence died two years later. Cause of death was not captured. Patients with FTC most often presented with pT2 tumors (57%). One patient presented with pN1b (4%). In 70%, no lymph nodes were collected. None of the patients with FTC developed a recurrence or died. Conclusion: Pediatric PTC and FTC are two distinct diseases. Recurrence in pediatric PTC is common, but in FTC it is not. Survival for both pediatric PTC and FTC is very good.


Asunto(s)
Adenocarcinoma Folicular , Carcinoma Papilar , Neoplasias de la Tiroides , Adenocarcinoma Folicular/diagnóstico , Carcinoma Papilar/patología , Niño , Humanos , Estudios Retrospectivos , Cáncer Papilar Tiroideo/epidemiología , Neoplasias de la Tiroides/diagnóstico , Neoplasias de la Tiroides/epidemiología , Neoplasias de la Tiroides/terapia
3.
Front Endocrinol (Lausanne) ; 12: 717769, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34659111

RESUMEN

Background: Thyroidectomy is a treatment option in some benign thyroid disorders and the definitive treatment option for thyroid cancer. As postoperative mortality is extremely rare data on postoperative complications and long-term health consequences are important. Objective: To evaluate the frequencies of short- and long-term complications, and their risk factors in pediatric patients (0-18 years) who underwent a thyroidectomy in a tertiary children's hospital. Methods: A retrospective single center study was performed including all pediatric patients who underwent a thyroidectomy between January 2013 and February 2020. Results: Forty-eight patients were included in this study (mean age 14.6 years). Twenty-nine total thyroidectomies and 19 hemithyroidectomies were conducted. Thyroid carcinoma was the indication to perform a thyroidectomy in 12 patients, 36 patients underwent a thyroidectomy because of a benign thyroid disorder. Postoperative hypocalcemia was evaluated in patients who underwent a total thyroidectomy. Rapidly resolved hypocalcemia was observed in three patients (10.3%), transient hypocalcemia in 10 patients (34.5%) and permanent hypocalcemia in six patients (20.7%). Permanent hypocalcemia was only seen in patients who underwent a thyroidectomy combined with additional lymph node dissection because of thyroid carcinoma [thyroid carcinoma: OR 43.73, 95% CI (2.11-904.95); lymph node dissection: OR 76.14, 95% CI (3.49-458.98)]. Transient and permanent recurrent laryngeal nerve injury was reported in four (8.3%) and one (2.1%) of all patients, respectively. Conclusion: Permanent postoperative complications after thyroidectomy are rare in pediatric patients undergoing a thyroidectomy without lymph node dissection. However, in this age group permanent hypocalcemia occurs more frequently after thyroidectomy with additional lymph node dissection because of thyroid cancer. With respect to quality of life, especially of pediatric thyroid cancer patients, reducing this complication is an important goal.


Asunto(s)
Hipocalcemia/patología , Escisión del Ganglio Linfático/efectos adversos , Complicaciones Posoperatorias/patología , Calidad de Vida , Enfermedades de la Tiroides/cirugía , Tiroidectomía/efectos adversos , Adolescente , Niño , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Hipocalcemia/etiología , Masculino , Complicaciones Posoperatorias/etiología , Pronóstico , Estudios Retrospectivos , Factores de Riesgo
4.
Redox Biol ; 38: 101804, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33260088

RESUMEN

Pharmacological ascorbate (P-AscH-) combined with standard of care (SOC) radiation and temozolomide is being evaluated in a phase 2 clinical trial (NCT02344355) in the treatment of glioblastoma (GBM). Previously published data demonstrated that paramagnetic iron (Fe3+) catalyzes ascorbate's oxidation to form diamagnetic iron (Fe2+). Because paramagnetic Fe3+ may influence relaxation times observed in MR imaging, quantitative MR imaging of P-AscH--induced changes in redox-active Fe was assessed as a biomarker for therapy response. Gel phantoms containing either Fe3+ or Fe2+ were imaged with T2* and quantitative susceptibility mapping (QSM). Fifteen subjects receiving P-AscH- plus SOC underwent T2* and QSM imaging four weeks into treatment. Subjects were scanned: pre-P-AscH- infusion, post-P-AscH- infusion, and post-radiation (3-4 h between scans). Changes in T2* and QSM relaxation times in tumor and normal tissue were calculated and compared to changes in Fe3+ and Fe2+ gel phantoms. A GBM mouse model was used to study the relationship between the imaging findings and the labile iron pool. Phantoms containing Fe3+ demonstrated detectable changes in T2* and QSM relaxation times relative to Fe2+ phantoms. Compared to pre-P-AscH-, GBM T2* and QSM imaging were significantly changed post-P-AscH- infusion consistent with conversion of Fe3+ to Fe2+. No significant changes in T2* or QSM were observed in normal brain tissue. There was moderate concordance between T2* and QSM changes in both progression free survival and overall survival. The GBM mouse model showed similar results with P-AscH- inducing greater changes in tumor labile iron pools compared to the normal tissue. CONCLUSIONS: T2* and QSM MR-imaging responses are consistent with P-AscH- reducing Fe3+ to Fe2+, selectively in GBM tumor volumes and represent a potential biomarker of response. This study is the first application using MR imaging in humans to measure P-AscH--induced changes in redox-active iron.


Asunto(s)
Hierro , Imagen por Resonancia Magnética , Biomarcadores , Encéfalo , Oxidación-Reducción
5.
Front Oncol ; 10: 1311, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32850412

RESUMEN

Purpose: This study aimed to investigate the feasibility of stereotactic body radiation therapy (SBRT) as salvage therapy for locally recurrent esophageal cancer. We hypothesized that SBRT would provide durable treated tumor control with minimal associated toxicity in patients with progressive disease after definitive radiation, chemotherapy, and surgical resection. Methods: This single-institution retrospective study assessed outcomes in patients who received SBRT for locoregional failure of esophageal cancer after initial curative-intent treatment. Only patients who had received neoadjuvant chemoradiation (≥41.4 Gy) for esophageal cancer were selected. Subsequent surgical resection was optional but institutional follow-up by an oncologist was required. The primary endpoints of this study were gastrointestinal and constitutional toxicity, scored with the Common Terminology Criteria for Adverse Events v5.0. A secondary outcome, treated-tumor control, was assessed with RECIST v1.1. Results: Nine patients (11 locoregional recurrences) treated with SBRT were reviewed, with a median follow-up time of 10.5 months. Most patients initially presented with T3 (88.9%), N1 (55.6%), moderately differentiated (66.7%) adenocarcinoma (88.9%), and had received a median 50.4 Gy delivered over 28 fractions with concurrent carboplatin/paclitaxel chemotherapy followed by surgical resection. Median time to recurrence was 16.3 months. Median total dose delivered by SBRT was 27.5 Gy (delivered in five fractions). Two patients experienced acute grade 1 fatigue and vomiting. No patient experienced grade 3 or higher toxicity. One patient experienced failure in the SBRT treatment field at 5.8 months after treatment and six patients developed distant failure. The median progression-free survival time for SBRT-treated tumors was 5.0 months, and median overall survival time was 12.9 months. Conclusions: This single-institution study demonstrated the feasibility of SBRT for locoregional recurrence of esophageal cancer with minimal treatment-related toxicity and high rates of treated tumor control. Prospective studies identifying ideal salvage SBRT candidates for locoregional failure as well as validating its safety are needed.

7.
eNeuro ; 6(4)2019.
Artículo en Inglés | MEDLINE | ID: mdl-31387875

RESUMEN

Intrinsically photosensitive retinal ganglion cells (ipRGCs) are rare mammalian photoreceptors essential for non-image-forming vision functions, such as circadian photoentrainment and the pupillary light reflex. They comprise multiple subtypes distinguishable by morphology, physiology, projections, and levels of expression of melanopsin (Opn4), their photopigment. The molecular programs that distinguish ipRGCs from other ganglion cells and ipRGC subtypes from one another remain elusive. Here, we present comprehensive gene expression profiles of early postnatal and adult mouse ipRGCs purified from two lines of reporter mice that mark different sets of ipRGC subtypes. We find dozens of novel genes highly enriched in ipRGCs. We reveal that Rasgrp1 and Tbx20 are selectively expressed in subsets of ipRGCs, though these molecularly defined groups imperfectly match established ipRGC subtypes. We demonstrate that the ipRGCs regulating circadian photoentrainment are diverse at the molecular level. Our findings reveal unexpected complexity in gene expression patterns across mammalian ipRGC subtypes.


Asunto(s)
Células Ganglionares de la Retina/metabolismo , Transcriptoma , Animales , Ritmo Circadiano/fisiología , Femenino , Perfilación de la Expresión Génica , Factores de Intercambio de Guanina Nucleótido/metabolismo , Masculino , Ratones Transgénicos , Proteínas de Dominio T Box/metabolismo
8.
J Gastrointest Oncol ; 10(4): 597-604, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31392039

RESUMEN

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) has been shown to achieve decreased local recurrence (LR) with lower toxicity in rectal cancer patients, but data confirming the optimal timing of surgery following this therapy is less robust. METHODS: The University of Iowa Cancer Registry was queried to identify all patients with stages II-III rectal cancer who received nCRT and surgery from 2000 through 2012. Primary endpoints were time interval to surgery (TI), and overall survival (OS). Secondary endpoints included pathologic outcomes, perioperative morbidities and postoperative complications. Patient characteristics and treatment regimens were compared. Univariate Cox proportional hazard models were used to study the association between TI and OS. Associations of TI with secondary endpoints were tested using Chi-square tests of association. RESULTS: Eighty-seven patients presented with stages II-III rectal cancer. Mean TI was 9.92 weeks. There was no significant association between TI and OS when comparing <8 to ≥8 weeks (P=0.23) or when considering the interval as a continuous variable (P=0.85). Increased LOS [median 7.00 days, P=0.05, HR 1.03 (1.00-1.06)] did correlate with worse survival outcomes. Delaying surgery beyond 8 weeks was associated with increased risk for wound infection (P=0.05). CONCLUSIONS: OS was not influenced by longer intervals between nCRT and surgery. Delaying surgery beyond 8 weeks was associated with increased risk for wound infection.

9.
Cancer Res ; 78(24): 6838-6851, 2018 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-30254147

RESUMEN

: Chemoradiation therapy is the mainstay for treatment of locally advanced, borderline resectable pancreatic cancer. Pharmacologic ascorbate (P-AscH-, i.e., intravenous infusions of ascorbic acid, vitamin C), but not oral ascorbate, produces high plasma concentrations capable of selective cytotoxicity to tumor cells. In doses achievable in humans, P-AscH- decreases the viability and proliferative capacity of pancreatic cancer via a hydrogen peroxide (H2O2)-mediated mechanism. In this study, we demonstrate that P-AscH- radiosensitizes pancreatic cancer cells but inhibits radiation-induced damage to normal cells. Specifically, radiation-induced decreases in clonogenic survival and double-stranded DNA breaks in tumor cells, but not in normal cells, were enhanced by P-AscH-, while radiation-induced intestinal damage, collagen deposition, and oxidative stress were also reduced with P-AscH- in normal tissue. We also report on our first-in-human phase I trial that infused P-AscH- during the radiotherapy "beam on." Specifically, treatment with P-AscH- increased median overall survival compared with our institutional average (21.7 vs. 12.7 months, P = 0.08) and the E4201 trial (21.7 vs. 11.1 months). Progression-free survival in P-AscH--treated subjects was also greater than our institutional average (13.7 vs. 4.6 months, P < 0.05) and the E4201 trial (6.0 months). Results indicated that P-AscH- in combination with gemcitabine and radiotherapy for locally advanced pancreatic adenocarcinoma is safe and well tolerated with suggestions of efficacy. Because of the potential effect size and minimal toxicity, our findings suggest that investigation of P-AscH- efficacy is warranted in a phase II clinical trial. SIGNIFICANCE: These findings demonstrate that pharmacologic ascorbate enhances pancreatic tumor cell radiation cytotoxicity in addition to offering potential protection from radiation damage in normal surrounding tissue, making it an optimal agent for improving treatment of locally advanced pancreatic adenocarcinoma.


Asunto(s)
Ácido Ascórbico/farmacología , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/radioterapia , Anciano , Anciano de 80 o más Años , Animales , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular , Colágeno/metabolismo , Daño del ADN , Desoxicitidina/administración & dosificación , Desoxicitidina/análogos & derivados , Supervivencia sin Enfermedad , Femenino , Glutatión/metabolismo , Humanos , Masculino , Ratones , Ratones Desnudos , Persona de Mediana Edad , Estrés Oxidativo , Tolerancia a Radiación , Radioterapia , Proteínas Recombinantes/metabolismo , Resultado del Tratamiento , Gemcitabina
10.
Neuron ; 98(5): 870-872, 2018 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-29879387

RESUMEN

In this issue of Neuron, Stoeber et al. (2018) report a biosensor resolving the spatiotemporal organization of opioid receptor activation in living neurons. They delineate novel signaling mechanisms in endosomes and Golgi differentially engaged by opioid peptides and drugs.


Asunto(s)
Analgésicos Opioides , Técnicas Biosensibles , Neuronas , Transducción de Señal/efectos de los fármacos
11.
Radiat Res ; 189(5): 456-465, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29547353

RESUMEN

Gastric adenocarcinoma most often presents at an advanced stage and overall five-year survival of ∼30%. Pharmacological ascorbate (high-dose IV ascorbate) has been proposed as a promising nontoxic adjuvant to standard radio-chemotherapies in several cancer types. In the current study, pharmacological ascorbate (0.5-2 m M) caused a dose-dependent decrease (70-85% at 2 m M) in clonogenic survival of gastric adenocarcinoma cells (AGS and MNK-45), but was relatively nontoxic to a small intestinal epithelial nonimmortalized human cell isolate (FHs 74 Int). The addition of pharmacological ascorbate (1 m M) to standard radio-chemotherapies [i.e., 5-FU (5 µ M); cisplatin (0.5 µ M); irinotecan (2.5 µ M); carboplatin (5 µ M); paclitaxel (2-4 n M); and X rays (1.8 Gy)] also potentiated gastric cancer clonogenic cell killing [additional decreases were noted with: ascorbate plus 5-FU/radiation (1%); ascorbate plus cisplatin/irinotecan (9-19%); and ascorbate plus paclitaxel/carboplatin (6-7%)]. The gastric cancer cell toxicity and chemosensitization seen with pharmacological ascorbate was dependent on H2O2 and the presence of catalytic metal ions. In addition, pharmacological ascorbate dosing resulted in a concentration-dependent decrease (64% at 20 m M, P ≤ 0.0001) in cancer cell invasion and migration that was inhibited by catalase. Finally, pharmacological ascorbate significantly increased the overall survival of mice with gastric cancer xenografts when used in combination with paclitaxel, carboplatin and radiation ( P = 0.019). These results demonstrate that pharmacological ascorbate is selectively cytotoxic to gastric adenocarcinoma cells (relative to normal intestinal epithelial cells) by a mechanism involving H2O2 and redox active metal ions. Furthermore, pharmacological ascorbate significantly enhances gastric cancer xenograft responses to radio-chemotherapy as well as inhibiting tumor cell migration and invasiveness. Overall, these results support the hypothesis that pharmacological ascorbate can be used as an adjuvant with standard-of-care radio-chemotherapies for the treatment of gastric adenocarcinomas.


Asunto(s)
Adenocarcinoma/terapia , Ácido Ascórbico/farmacología , Quimioradioterapia , Neoplasias Gástricas/terapia , Adenocarcinoma/patología , Animales , Ácido Ascórbico/uso terapéutico , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Relación Dosis-Respuesta en la Radiación , Sinergismo Farmacológico , Femenino , Humanos , Ratones , Neoplasias Gástricas/patología , Ensayos Antitumor por Modelo de Xenoinjerto
12.
Redox Biol ; 14: 82-87, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-28886484

RESUMEN

Pharmacological doses (> 1mM) of ascorbate (a.k.a., vitamin C) have been shown to selectively kill cancer cells through a mechanism that is dependent on the generation of H2O2 at doses that are safely achievable in humans using intravenous administration. The process by which ascorbate oxidizes to form H2O2 is thought to be mediated catalytically by redox active metal ions such as iron (Fe). Because intravenous iron sucrose is often administered to colon cancer patients to help mitigate anemia, the current study assessed the ability of pharmacological ascorbate to kill colon cancer cells in the presence and absence of iron sucrose. In vitro survival assays showed that 10mM ascorbate exposure (2h) clonogenically inactivated 40-80% of exponentially growing colon cancer cell lines (HCT116 and HT29). When the H2O2 scavenging enzyme, catalase, was added to the media, or conditionally over-expressed using a doxycycline inducible vector, the toxicity of pharmacological ascorbate was significantly blunted. When colon cancer cells were treated in the presence or absence of 250µM iron sucrose, then rinsed, and treated with 10mM ascorbate, the cells demonstrated increased levels of labile iron that resulted in significantly increased clonogenic cell killing, compared to pharmacological ascorbate alone. Interestingly, when colon cancer cells were treated with iron sucrose for 1h and then 10mM ascorbate was added to the media in the continued presence of iron sucrose, there was no enhancement of toxicity despite similar increases in intracellular labile iron. The combination of iron chelators, deferoxamine and diethylenetriaminepentaacetic acid, significantly inhibited the toxicity of either ascorbate alone or ascorbate following iron sucrose. These observations support the hypothesis that increasing intracellular labile iron pools, using iron sucrose, can be used to increase the toxicity of pharmacological ascorbate in human colon cancer cells by a mechanism involving increased generation of H2O2.


Asunto(s)
Ácido Ascórbico/toxicidad , Compuestos Férricos/farmacología , Ácido Glucárico/farmacología , Hierro/metabolismo , Estrés Oxidativo/efectos de los fármacos , Catalasa/metabolismo , Supervivencia Celular/efectos de los fármacos , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Deferoxamina/farmacología , Sacarato de Óxido Férrico , Células HCT116 , Células HT29 , Humanos , Peróxido de Hidrógeno/metabolismo , Quelantes del Hierro/farmacología
13.
J Clin Transl Res ; 3(Suppl 3): 411-423, 2018 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-30873490

RESUMEN

BACKGROUND AND AIM: Medical specialists aim to provide evidence-based care based on the most recent scientific insights, but with the ongoing expansion of medical literature it seems unfeasible to remain updated. "Black-box" decision support tools such as Watson for Oncology (Watson) are gaining attention as they offer a promising opportunity to conquer this challenging issue, but it is not known if the advice given is congruent with guidelines or clinically valid in other settings. We present a protocol for the content evaluation of black-box decision support tools and a feasibility study to test the content and usability of Watson using this protocol. METHODS: The protocol consists of developing synthetic patient cases based on Dutch guidelines and expert opinion, entering the synthetic cases into Watson and Oncoguide, noting the response of each system and evaluating the result using a cross-tabulation scoring system resulting in a score range of -12 to +12. Treatment options that were not recommended according to the Dutch guideline were labeled with a "red flag" if Watson recommended it, and an "orange flag" if Watson suggested it for consideration. To test the feasibility of applying the protocol, we developed synthetic patient cases for the adjuvant treatment of stage I to stage III colon cancer based on relevant patient, clinical and tumor characteristics and followed our protocol. Additionally, for the feasibility study we also compared the recommendations from the NCCN guideline with Watson's advice, and evaluated usability by a cognitive walkthrough method. RESULTS: In total, we developed 190 synthetic patient cases (stage I: n=8; stage II: n=110; and stage III: n=72). Overall concordance scores per case for Watson versus Oncoguide ranged from a minimum score of -4 (n=6) to a maximum score of+12 (n=17) and from -4 (n=9) to +12 (n=24) for Watson versus the NCCN guidelines). In total, 69 cases (36%) were labeled with red flags, 96 cases (51%) with orange flags and 25 cases (13%) without flags. For the comparison of Watson with the NCCN guidelines, no red or orange flags were identified. CONCLUSIONS: We developed a research protocol for the evaluation of a black-box decision support tool, which proved useful and usable in testing the content and usability of Watson. Overall concordance scores ranged considerably between synthetic cases for both comparisons between Watson versus Oncoguide and Watson versus NCCN. Non-concordance is partially attributable to guideline differences between the United States and The Netherlands. This implies that further adjustments and localization are required before implementation of Watson outside the United States. RELEVANCE FOR PATIENTS: This study describes the first steps of content evaluation of a decision support tool before implementation in daily oncological patient care. The ultimate goal of the incorporation of decision support tools in daily practice is to improve personalized medicine and quality of care.

14.
J Am Chem Soc ; 139(41): 14399-14405, 2017 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-28931277

RESUMEN

This study reports a method for correlating the radical recombination efficiencies (FcP) of geminate radical cage pairs to the properties of the solvent. Although bulk viscosity (macroviscosity) is typically used to predict or interpret radical recombination efficiencies, the work reported here shows that microviscosity is a much better parameter. The use of microviscosity is valid over a range of different solvent system types, including nonpolar, aromatic, polar, and hydrogen bonding solvents. In addition, the relationship of FcP to microviscosity holds for solvent systems containing mixtures of these solvent types. The microviscosities of the solvent systems were straightforwardly determined by measuring the diffusion coefficient of an appropriate probe by NMR DOSY spectroscopy. By using solvent mixtures, selective solvation was shown to not affect the correlation between FcP and microviscosity. In addition, neither solvent polarity nor radical rotation affects the correlation between FcP and the microviscosity.

16.
Cancer Cell ; 31(4): 487-500.e8, 2017 04 10.
Artículo en Inglés | MEDLINE | ID: mdl-28366679

RESUMEN

Pharmacological ascorbate has been proposed as a potential anti-cancer agent when combined with radiation and chemotherapy. The anti-cancer effects of ascorbate are hypothesized to involve the autoxidation of ascorbate leading to increased steady-state levels of H2O2; however, the mechanism(s) for cancer cell-selective toxicity remain unknown. The current study shows that alterations in cancer cell mitochondrial oxidative metabolism resulting in increased levels of O2⋅- and H2O2 are capable of disrupting intracellular iron metabolism, thereby selectively sensitizing non-small-cell lung cancer (NSCLC) and glioblastoma (GBM) cells to ascorbate through pro-oxidant chemistry involving redox-active labile iron and H2O2. In addition, preclinical studies and clinical trials demonstrate the feasibility, selective toxicity, tolerability, and potential efficacy of pharmacological ascorbate in GBM and NSCLC therapy.


Asunto(s)
Ácido Ascórbico/farmacología , Neoplasias Encefálicas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Glioblastoma/tratamiento farmacológico , Hierro/metabolismo , Neoplasias Pulmonares/tratamiento farmacológico , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Ácido Ascórbico/administración & dosificación , Ácido Ascórbico/efectos adversos , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Línea Celular Tumoral , Quimioradioterapia/métodos , Femenino , Glioblastoma/metabolismo , Humanos , Peróxido de Hidrógeno/farmacología , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/radioterapia , Masculino , Ratones Desnudos , Oxígeno/metabolismo , Fármacos Sensibilizantes a Radiaciones/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto
17.
Radiat Res ; 187(6): 743-754, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28437190

RESUMEN

Ketogenic diets are low in carbohydrates and high in fat, which forces cells to rely more heavily upon mitochondrial oxidation of fatty acids for energy. Relative to normal cells, cancer cells are believed to exist under a condition of chronic mitochondrial oxidative stress that is compensated for by increases in glucose metabolism to generate reducing equivalents. In this study we tested the hypothesis that a ketogenic diet concurrent with radiation and chemotherapy would be clinically tolerable in locally advanced non-small cell lung cancer (NSCLC) and pancreatic cancer and could potentially exploit cancer cell oxidative metabolism to improve therapeutic outcomes. Mice bearing MIA PaCa-2 pancreatic cancer xenografts were fed either a ketogenic diet or standard rodent chow, treated with conventionally fractionated radiation (2 Gy/fraction), and tumor growth rates were assessed daily. Tumors were assessed for immunoreactive 4-hydroxy-2-nonenal-(4HNE)-modfied proteins as a marker of oxidative stress. Based on this and another previously published preclinical study, phase 1 clinical trials in locally advanced NSCLC and pancreatic cancer were initiated, combining standard radiation and chemotherapy with a ketogenic diet for six weeks (NSCLC) or five weeks (pancreatic cancer). The xenograft experiments demonstrated prolonged survival and increased 4HNE-modfied proteins in animals consuming a ketogenic diet combined with radiation compared to radiation alone. In the phase 1 clinical trial, over a period of three years, seven NSCLC patients enrolled in the study. Of these, four were unable to comply with the diet and withdrew, two completed the study and one was withdrawn due to a dose-limiting toxicity. Over the same time period, two pancreatic cancer patients enrolled in the trial. Of these, one completed the study and the other was withdrawn due to a dose-limiting toxicity. The preclinical experiments demonstrate that a ketogenic diet increases radiation sensitivity in a pancreatic cancer xenograft model. However, patients with locally advanced NSCLC and pancreatic cancer receiving concurrent radiotherapy and chemotherapy had suboptimal compliance to the oral ketogenic diet and thus, poor tolerance.


Asunto(s)
Quimioradioterapia/métodos , Dietoterapia/métodos , Dieta Cetogénica/métodos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Neoplasias Pancreáticas/terapia , Anciano , Anciano de 80 o más Años , Animales , Línea Celular Tumoral , Femenino , Humanos , Iowa , Masculino , Ratones , Ratones Desnudos , Persona de Mediana Edad , Neoplasias Pancreáticas/diagnóstico , Resultado del Tratamiento
18.
J Am Chem Soc ; 138(30): 9389-92, 2016 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-27430611

RESUMEN

This study reports the results of experiments that probed how solvents affect the recombination efficiency (FcP) of geminate radical cage pairs. The macroviscosity of solvents has traditionally been used to make quantitative predictions about FcP, but experiments reported here show that FcP varies dramatically for solvent systems with identical macroviscosities. Experiments show that FcP correlates with the solvent microviscosity: five different solvent systems (consisting of a solvent and a structurally similar viscogen) were examined, and FcP was the same for all five solvent systems at any particular microviscosity. The translational diffusion coefficient of the radicals (measured by DOSY) in the solvent system was used to define the microviscosity of the solvent system.

19.
World J Gastrointest Oncol ; 4(5): 103-8, 2012 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-22645633

RESUMEN

AIM: To study if HER-2 overexpression by locally advanced esophageal cancers increase the chance of brain metastasis following esophagectomy. METHODS: We retrospectively reviewed the medical records of esophageal cancer patients who underwent esophagectomy at University of Iowa Hospitals and Clinics between 2000 and 2010. Data analyzed consisted of demographic and clinical variables. The brain metastasis tissue was assayed for HER-2 overexpression utilizing the FDA approved DAKO Hercept Test(®). RESULTS: One hundred and forty two patients were reviewed. Median age was 64 years (36-86 years). Eighty eight patients (62%) received neoadjuvant chemoradiotherapy. Pathological complete and partial responses were achieved in 17 (19%) and 71 (81%) patients. Cancer relapsed in 43/142 (30%) patients. The brain was the first site of relapse in 9/43 patients (21%, 95% CI: 10%-36%). HER-2 immunohistochemistry testing of the brain metastasis tissue showed that 5/9 (56%) cases overexpressed HER-2 (3+ staining). CONCLUSION: HER-2 overexpression might be associated with increased risk of brain metastasis in esophageal cancer patients following esophagectomy. Further studies will be required to validate this observation.

20.
J Pediatr Gastroenterol Nutr ; 54(4): 471-6, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21873894

RESUMEN

OBJECTIVES: Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for the treatment of pain, fever, and inflammation. Long-term use of these drugs is associated with significant gastric injury. Activated neutrophils and oxidative stress seem to play a significant role in NSAID-induced gastric mucosal damage. The objective of our study is to examine the protective effects of an antioxidant and anti-inflammatory enzyme, heme oxygenase-1 (HO-1), in NSAID-induced gastric injury. METHODS: Mice were intraperitoneally injected with indomethacin (10 mg/kg) or sham. A specific inducer of HO-1, cobalt protoporphyrin (5 mg/kg), was given 24 hours before indomethacin to allow for the expression of HO-1. Controls received sham treatment. Twenty-four hours after indomethacin injection, gastric tissue damage was examined with histology. HO-1 expression was measured with immunoblot; cytokine levels were measured with enzyme-linked immunosorbent assay. Neutrophil infiltration was quantified with myeloperoxidase assay. Using electron paramagnetic resonance and desferrioxamine, we measured the labile iron pool in the mouse stomach as a marker of oxidative stress. RESULTS: Indomethacin caused gastric inflammation and ulcers, neutrophil activation, and increased tissue expression of interleukin-6 and tumor necrosis factor-alpha in mice. Inducing HO-1 with cobalt protoporphyrin reduced gastric inflammation, number of stomach ulcers, tissue neutrophil activation, and proinflammatory cytokine expression caused by indomethacin. CONCLUSIONS: These findings suggest that the induction of an anti-inflammatory and cytoprotective enzyme HO-1 may be a strategy to overcome the gastrointestinal adverse effects limiting the use of NSAIDs.


Asunto(s)
Antiinflamatorios no Esteroideos/efectos adversos , Hemo-Oxigenasa 1/metabolismo , Indometacina/efectos adversos , Proteínas de la Membrana/metabolismo , Úlcera Gástrica/inducido químicamente , Úlcera Gástrica/patología , Animales , Antiinflamatorios no Esteroideos/farmacología , Apoptosis/efectos de los fármacos , Ensayo de Inmunoadsorción Enzimática/métodos , Mucosa Gástrica/efectos de los fármacos , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patología , Indometacina/farmacología , Interleucina-6/genética , Interleucina-6/metabolismo , Ratones , Infiltración Neutrófila/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo
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