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1.
Cancer Res ; 84(18): 3004-3022, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-38959335

RESUMEN

TP53 tumor suppressor is frequently altered in lethal, castration-resistant prostate cancer (CRPC). However, to date there are no effective treatments that specifically target TP53 alterations. Using transcriptomic and metabolomic analyses, we have shown here that TP53-altered prostate cancer exhibits an increased dependency on asparagine (Asn) and overexpresses Asn synthetase (ASNS), the enzyme catalyzing the synthesis of Asn. Mechanistically, the loss or mutation of TP53 transcriptionally activated ASNS expression, directly and via mTORC1-mediated ATF4 induction, driving de novo Asn biosynthesis to support CRPC growth. TP53-altered CRPC cells were sensitive to Asn restriction by knockdown of ASNS or L-asparaginase treatment to deplete the intracellular and extracellular sources of Asn, respectively, and cell viability was rescued by Asn addition. Notably, pharmacological inhibition of intracellular Asn biosynthesis using a glutaminase inhibitor and depletion of extracellular Asn with L-asparaginase significantly reduced Asn production and effectively impaired CRPC growth. This study highlights the significance of ASNS-mediated metabolic adaptation as a synthetic vulnerability in CRPC with TP53 alterations, providing a rationale for targeting Asn production to treat these lethal prostate cancers. Significance: TP53-mutated castration-resistant prostate cancer is dependent on asparagine biosynthesis due to upregulation of ASNS and can be therapeutically targeted by approaches that deplete intracellular and extracellular asparagine.


Asunto(s)
Asparagina , Neoplasias de la Próstata Resistentes a la Castración , Proteína p53 Supresora de Tumor , Masculino , Humanos , Neoplasias de la Próstata Resistentes a la Castración/metabolismo , Neoplasias de la Próstata Resistentes a la Castración/patología , Neoplasias de la Próstata Resistentes a la Castración/genética , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Asparagina/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Proteína p53 Supresora de Tumor/genética , Ratones , Animales , Línea Celular Tumoral , Aspartatoamoníaco Ligasa/genética , Aspartatoamoníaco Ligasa/metabolismo , Factor de Transcripción Activador 4/metabolismo , Factor de Transcripción Activador 4/genética , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Proliferación Celular , Ligasas de Carbono-Nitrógeno con Glutamina como Donante de Amida-N
2.
Cureus ; 16(5): e59725, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38841010

RESUMEN

INTRODUCTION:  Motion analysis, the study of movement patterns to evaluate performance, plays a crucial role in surgical training. It provides objective data that can be used to assess and improve trainee's precision, efficiency, and overall surgical technique. The primary aim of this study is to employ accelerometer-based sensors placed on the wrist to analyze hand motions during endoscopic sinus surgery training using the sheep's head. By capturing detailed movement data, the study seeks to quantify the motion characteristics that distinguish different levels of surgical expertise. This approach seeks to quantify motion characteristics indicative of surgical expertise and enhance the objectivity and effectiveness of surgical training feedback mechanisms. MATERIALS AND METHODS:  Twenty-four participants were divided into three groups based on their experience with endoscopic endonasal surgery. Each participant was tasked with performing specified procedures on an individual sheep's head, concentrating on exploring both nasal passages. A single Bluetooth Accelerometer WitMotion sensor was mounted on the dorsal surface of each hand. This facilitates the evaluation of efficiency parameters such as time, path length, and acceleration during the training procedures. Accelerometer data were collected and imported in CSV format (comma-separated values) for each group of surgeons-senior, specialist, and resident-mean values and standard deviations were computed. The Shapiro-Wilk Test assessed the normality of the distribution. The Kruskal-Wallis test was employed to compare procedural time, acceleration, and path length differences across the three surgeon experience levels. RESULTS:  For the procedural time, statistical significance appears in all surgical steps (p<0.001), with the biggest difference in the septoplasty group in favor of the senior group. A clear difference can be observed between the resulting acceleration of the dominant hands (instrument hand) and the non-dominant hand (endoscopic hand) and between the study groups. The difference between groups reaches statistical significance with a p-value <0.001. A statistically significant difference can be seen between the paths covered by each hand of every participant (p<0.001). Also, senior doctors covered significantly less movement with both hands than the specialists and the resident doctors (p<0.001). CONCLUSIONS:  The data show a clear learning curve from resident to senior, with residents taking more time and using more hand movements to complete the same tasks. Specialists are in the intermediate phase, showing signs of honing their technique towards efficiency. This comprehensive data set can help tailor training programs to focus on both efficiency (quicker procedures) and economy of motion (reduced path length and acceleration), especially in more complex procedures where the difference in performance is more pronounced.

3.
Cureus ; 16(2): e53529, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38445146

RESUMEN

INTRODUCTION: Training young doctors in functional endoscopic sinus surgery requires dedicated centers for cadaveric dissections. However, ethical constraints have limited cadaver availability. Alternative anatomical models, like the ovine model, are being explored for effective training, offering easier procurement and resembling human head anatomy. This study aims to demonstrate that the ovine model is useful for endoscopic sinus surgery training, highlighting the anatomical, imaging, histological, and endoscopic aspects. METHODS: Three adult Native Romanian Turcana sheep's heads were obtained fresh and frozen from a local slaughterhouse. Using a helical scanner, CT scans were performed, and anatomical structures in the images were carefully labeled. Two heads frozen at -20°C were serially sectioned, with one cut sagittally, dividing the skull, and the other head sectioned transversely with 2.5 cm thickness. Sectional photographs were taken. The third sheep's head underwent endoscopy, and samples from the septal mucosa and inferior turbinate were collected for histopathology examination. The specimens were processed, stained, and examined by a pathologist. RESULTS: The study successfully highlighted the gross anatomy, CT imaging aspects, histological characteristics of sheep nasal mucosa, and endoscopic features, demonstrating the similarity of the sheep's head to human anatomy, making it a suitable anatomical training model for endoscopic sinus surgery. CONCLUSION: The use of sheep's heads as substitutes for human cadaver heads in nasal surgery simulations presents a promising avenue for research. The anatomical similarities and cost-effectiveness make sheep's heads a practical choice for certain aspects of nasal surgery investigation. However, researchers must approach this methodology with a thorough understanding of its limitations, including anatomical and biomechanical differences. Validation studies comparing outcomes with human models are crucial to establishing reliability. The sheep's head anatomical model provides a highly valuable experience for young trainees in endoscopic sinus surgery. Despite encountering several challenges, including some anatomical differences, considering its advantageous attributes renders it an ideal material for mimicking surgical procedures in functional endoscopic sinus surgery.

4.
Sci Rep ; 13(1): 22574, 2023 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-38114536

RESUMEN

The Carpathian Mountains have been constantly inhabited by grey wolves and present one of the largest distribution areas in Europe, comprising between 2300 and 2700 individuals in Romania. To date, however, relatively little is known about the Romanian wolf population. We aimed to provide a first assessment of genetic diversity, population structure and wolf-dog hybridisation based on 444 mostly non-invasively collected samples in the Eastern Romanian Carpathians. Pack reconstruction and analysis of population genetic parameters were performed with mitochondrial DNA control-region sequencing and microsatellite genotyping. We found relatively high levels of genetic diversity, which is similar to values found in previous studies on Carpathian wolves from Poland and Slovakia, as well as to the long-lasting Dinaric-Balkan wolf population. We found no significant population structure in our study region, suggesting effective dispersal and admixture. Analysis of wolf-dog hybridisation using a Single Nucleotide Polymorphism panel optimised for hybrid detection revealed low rates of admixture between wolves and domestic dogs. Our results provide evidence for the existence of a genetically viable wolf population in the Romanian Carpathians. The genetic data obtained in this study may serve as valuable baseline information for the elaboration of monitoring standards and management plans for wolves in Romania.


Asunto(s)
Genética de Población , Lobos , Animales , Lobos/genética , Rumanía , Europa (Continente) , Variación Genética
5.
Cancer ; 129(21): 3390-3404, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37498973

RESUMEN

BACKGROUND: The published literature on hematological, clinical, flowcytometric-immunophenotyping, and minimal residual disease outcomes of the prognostically important genetic subtypes of acute lymphoblastic leukemia (ALL) is scarce from low-income countries. For newer classifications such as BCR::ABL1-like ALLs, the scarcity of patient-level data is even more pronounced. METHODS: The authors performed comprehensive detection of recurrent gene fusions and BCR::ABL1-like ALL cases followed by immunophenotypic profiling and obtained clinical outcome parameters for a large cohort (n = 1021) of patients from India. This cohort included a significant number of patients with BCR::ABL1-like ALL subtype and other genetic subtypes of ALL. RESULTS: Patients with BCR::ABL1-positive and BCR::ABL1-like ALL were significantly older, had male preponderance, and expressed a higher white blood cell count than BCR::ABL1-negative cases (p < .05). Logistic regression modeling of B-lineage-ALL (B-ALL) subtypes revealed that cluster of differentiation (CD)36 is a strong statistically significant predictive marker of BCR::ABL1-like ALL (p < .05). Furthermore, patients with BCR::ABL1-like ALLs show a significantly higher frequency of CD36 expression compared to BCR::ABL1-negative ALLs (p < .05). In terms of clinical symptoms, lymphadenopathy is a strong statistically significant predictive marker in BCR::ABL1-like ALLs compared to BCR::ABL1-negative ALL cases (p < .05). In terms of treatment outcomes, minimal residual disease (MRD) positivity in BCR::ABL1-positive ALL cases were statistically significant (p < .05), and BCR::ABL1-like ALL cases had high MRD-positivity as compared to BCR::ABL1-negative ALL cases but did not show statistical significance. CONCLUSIONS: The findings evince the use of novel therapies and personalized treatment regimens to improve the overall survival of the newer incorporated entities in B-ALLs. This is the first report characterizing the hematological, clinical, flowcytometric-immunophenotyping, and minimal residual disease outcomes of the prognostically significant subtypes of ALLs in patients from India. PLAIN LANGUAGE SUMMARY: Characterizing the hematological, clinical, flowcytometric-immunophenotyping, and minimal residual disease outcomes of the prognostically significant subtypes (n = 1021) of acute lymphoblastic leukemia (ALLs) in patients from India. We have made two independent logistic regression models of cluster of differentiation (CD) markers and clinical symptoms to differentiate prognostically significant subtypes of ALLs. Logistic regression analysis of CD markers revealed CD36 as a strong predictor in BCR::ABL1-like ALL cases compared to BCR::ABL1-negative ALL cases. Logistic regression analysis of clinical symptoms revealed lymphadenopathy significantly predicts BCR::ABL1-like ALLs (p < .05). In terms of treatment outcomes, BCR::ABL1-positive ALL had statistically significant minimal residual disease (MRD) (p < .05), and BCR::ABL1-like ALL cases had high MRD-positivity but did not show statistical significance as compared to BCR::ABL1-negative ALLs.

6.
Sci Adv ; 8(17): eabh3635, 2022 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-35476451

RESUMEN

MYC regulates multiple gene programs, raising questions about the potential selectivity and downstream transcriptional consequences of MYC inhibitors as cancer therapeutics. Here, we examined the effect of a small-molecule MYC inhibitor, MYCi975, on the MYC/MAX cistromes, epigenome, transcriptome, and tumorigenesis. Integrating these data revealed three major classes of MYCi975-modulated gene targets: type 1 (down-regulated), type 2 (up-regulated), and type 3 (unaltered). While cell cycle and signal transduction pathways were heavily targeted by MYCi, RNA biogenesis and core transcriptional pathway genes were spared. MYCi975 altered chromatin binding of MYC and the MYC network family proteins, and chromatin accessibility and H3K27 acetylation alterations revealed MYCi975 suppression of MYC-regulated lineage factors AR/ARv7, FOXA1, and FOXM1. Consequently, MYCi975 synergistically sensitized resistant prostate cancer cells to enzalutamide and estrogen receptor-positive breast cancer cells to 4-hydroxytamoxifen. Our results demonstrate that MYCi975 selectively inhibits MYC target gene expression and provide a mechanistic rationale for potential combination therapies.


Asunto(s)
Neoplasias de la Mama , Epigenómica , Cromatina/genética , Expresión Génica , Humanos , Masculino , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo
7.
Cancer Res ; 82(11): 2110-2123, 2022 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-35405009

RESUMEN

Androgen receptor (AR) pathway inhibitors are the mainstay treatment for advanced prostate cancer, but resistance to therapy is common. Here, we used a CRISPR activation screen in metastatic castration-sensitive prostate cancer cells to identify genes that promote resistance to AR inhibitors. Activation of the TGFß target gene paired-related homeobox2 (PRRX2) promoted enzalutamide resistance. PRRX2 expression was the highest in double-negative prostate cancer (DNPC), which lack AR signaling and neuroendocrine differentiation, and a PRRX2-related gene signature identified a subset of patients with DNPC with reduced overall survival. PRRX2-expressing cells showed alterations in the CDK4/6/Rb/E2F and BCL2 pathways. Accordingly, treatment with CDK4/6 and BCL2 inhibitors sensitized PRRX2-expressing, castration-resistant tumors to enzalutamide. Overall, PRRX2 was identified as a driver of enzalutamide resistance. The PRRX2 signature merits investigation as a biomarker of enzalutamide resistance in prostate cancer that could be reversed with CDK4/6 and BCL2 inhibitors. SIGNIFICANCE: PRRX2 mediates enzalutamide resistance via activation of the E2F and BCL2 pathways, which can be targeted with CDK4/6 and BCL2 inhibitors to reverse resistance.


Asunto(s)
Antineoplásicos , Neoplasias de la Próstata Resistentes a la Castración , Antagonistas de Receptores Androgénicos/farmacología , Antineoplásicos/farmacología , Benzamidas , Línea Celular Tumoral , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Resistencia a Antineoplásicos/genética , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Masculino , Nitrilos/uso terapéutico , Feniltiohidantoína , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Neoplasias de la Próstata Resistentes a la Castración/genética , Neoplasias de la Próstata Resistentes a la Castración/patología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Receptores Androgénicos/metabolismo
8.
J Med Case Rep ; 15(1): 428, 2021 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-34404447

RESUMEN

INTRODUCTION: Gastrointestinal stromal tumors represent the most frequently encountered primary mesenchymal tumors. Whereas the liver and the peritoneum are known to be the preferential metastasis sites, no therapeutic standard has yet been established for the management of bone metastases because of their very low incidence. We report a unique example of a single humerus metastasis of a jejunal gastrointestinal stromal tumor. CASE PRESENTATION: We report the case of a 72-year-old European woman whose jejunal gastrointestinal stromal tumor was resected in 2013 and treated during the following 3 years with imatinib (400 mg daily). In 2018, she developed a single humeral bone lesion that was identified as a gastrointestinal stromal tumor metastasis. After 7 months of imatinib intake, reconstructive surgery was performed. Pathologists confirmed the satisfactory histological regression and assessed the complete tumor resection. The patient is still on imatinib maintenance therapy, with no recurrence reported so far. She fully recovered the upper limb function after following an appropriate rehabilitation program. DISCUSSION: Current literature and published case reports indicate that bones are one of the rarest locations of gastrointestinal stromal tumor metastasis (about 1%), with occurrence mainly in the spine. Patients initially diagnosed with gastrointestinal stromal tumor of the small intestine and stomach are more likely to suffer from bone metastasis, compared with other gastrointestinal stromal tumor locations. The median overall survival rate is higher for patients with isolated bone metastasis compared with those having liver metastasis. Metastasis occurs on average 4 years after the primary, but it may take up to 20 years, emphasizing the need for long-term clinical and radiological monitoring. Although specific guidelines for such cases have not yet been established, we suggest that a multimodal concerted approach involving surgery or radiotherapy associated with tyrosine kinase inhibitor intake should be considered. CONCLUSION: Bones are one of the rarest locations of gastrointestinal stromal tumor metastasis. A multidisciplinary collaboration was set up to allow conservative surgery of our patient after several months of imatinib treatment. A year and a half later, the patient is still in complete remission. This specific case supports the concept of an intermediate stage between local and oligometastatic disease that should be managed with a curative aim, as much as possible.


Asunto(s)
Antineoplásicos , Tumores del Estroma Gastrointestinal , Neoplasias Hepáticas , Anciano , Antineoplásicos/uso terapéutico , Femenino , Tumores del Estroma Gastrointestinal/cirugía , Humanos , Húmero , Mesilato de Imatinib/uso terapéutico , Recurrencia Local de Neoplasia
9.
Science ; 372(6546): 1049, 2021 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-34083480
10.
Cancer Res ; 81(2): 248-253, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-33087323

RESUMEN

MYC is a highly validated oncogenic transcription factor and cancer target. However, the disordered nature of this protein has made it a challenging target, with no clinical stage, direct small-molecule MYC inhibitors available. Recent work leveraging a large in silico chemical library and a rapid in vivo screen has expanded the chemotypes of direct small-molecule inhibitors (MYCi). Novel MYCi represent a class of improved MYC chemical probes that bind directly to MYC to inhibit its function and to promote its degradation by enhancing GSK3ß-mediated phosphorylation. One of these compounds, MYCi975, has shown remarkable tolerability and efficacy in vivo and is associated with a selective effect on MYC target gene expression. Additional effects of MYCi on the tumor immune microenvironment including immune cell infiltration and upregulation of PD-L1 expression provide a rationale for combining MYCi with anti-PD-1/PD-L1 therapy to enhance antitumor efficacy. Our strategy for developing MYCi demonstrates an efficient way to identify selective and well-tolerated MYC inhibitors. The new MYCi provide tools for probing MYC function and serve as starting points for the development of novel anti-MYC therapeutics.


Asunto(s)
Antineoplásicos/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-myc/antagonistas & inhibidores , Bibliotecas de Moléculas Pequeñas/farmacología , Microambiente Tumoral/efectos de los fármacos , Animales , Humanos , Neoplasias/metabolismo , Neoplasias/patología , Proteínas Proto-Oncogénicas c-myc/genética
11.
Life Sci Alliance ; 4(2)2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33328249

RESUMEN

Genetic coessentiality analysis, a computational approach which identifies genes sharing a common effect on cell fitness across large-scale screening datasets, has emerged as a powerful tool to identify functional relationships between human genes. However, widespread implementation of coessentiality to study individual genes and pathways is limited by systematic biases in existing coessentiality approaches and accessibility barriers for investigators without computational expertise. We created FIREWORKS, a method and interactive tool for the construction and statistical analysis of coessentiality networks centered around gene(s) provided by the user. FIREWORKS incorporates a novel bias reduction approach to reduce false discoveries, enables restriction of coessentiality analyses to custom subsets of cell lines, and integrates multiomic and drug-gene interaction datasets to investigate and target contextual gene essentiality. We demonstrate the broad utility of FIREWORKS through case vignettes investigating gene function and specialization, indirect therapeutic targeting of "undruggable" proteins, and context-specific rewiring of genetic networks.


Asunto(s)
Biología Computacional/métodos , Regulación de la Expresión Génica , Redes Reguladoras de Genes , Genómica , Programas Informáticos , Sistemas CRISPR-Cas , Marcación de Gen , Sitios Genéticos , Genómica/métodos , Humanos , Modelos Biológicos
12.
Cancer Cell ; 36(5): 483-497.e15, 2019 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-31679823

RESUMEN

Small molecules that directly target MYC and are also well tolerated in vivo will provide invaluable chemical probes and potential anti-cancer therapeutic agents. We developed a series of small-molecule MYC inhibitors that engage MYC inside cells, disrupt MYC/MAX dimers, and impair MYC-driven gene expression. The compounds enhance MYC phosphorylation on threonine-58, consequently increasing proteasome-mediated MYC degradation. The initial lead, MYC inhibitor 361 (MYCi361), suppressed in vivo tumor growth in mice, increased tumor immune cell infiltration, upregulated PD-L1 on tumors, and sensitized tumors to anti-PD1 immunotherapy. However, 361 demonstrated a narrow therapeutic index. An improved analog, MYCi975 showed better tolerability. These findings suggest the potential of small-molecule MYC inhibitors as chemical probes and possible anti-cancer therapeutic agents.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Antígeno B7-H1/farmacología , Descubrimiento de Drogas/métodos , Neoplasias/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-myc/antagonistas & inhibidores , Animales , Antineoplásicos Inmunológicos/farmacología , Antineoplásicos Inmunológicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Antígeno B7-H1/antagonistas & inhibidores , Antígeno B7-H1/metabolismo , Antígeno B7-H1/uso terapéutico , Línea Celular Tumoral , Resistencia a Antineoplásicos/efectos de los fármacos , Sinergismo Farmacológico , Estudios de Factibilidad , Femenino , Humanos , Masculino , Ratones , Neoplasias/inmunología , Neoplasias/patología , Fosforilación/efectos de los fármacos , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteolisis/efectos de los fármacos , Proteínas Proto-Oncogénicas c-myc/metabolismo , Treonina/metabolismo , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/inmunología , Regulación hacia Arriba/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto
13.
Chem Sci ; 10(6): 1866-1872, 2019 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-30842855

RESUMEN

Novel functionalities may be achieved in oxide electronics by appropriate stacking of planar oxide layers of different metallic species, MO p and M'O q . The simplest mechanism allowing the tailoring of the electronic states and physical properties of such heterostructures is of electrostatic nature-charge imbalance between the M and M' cations. Here we clarify the effect of interlayer electrostatics on the anisotropic Kitaev exchange in H3LiIr2O6, a recently proposed realization of the Kitaev spin liquid. By quantum chemical calculations, we show that the precise position of H+ cations between magnetically active [LiIr2O6]3- honeycomb-like layers has a strong impact on the magnitude of Kitaev interactions. In particular, it is found that stacking with straight interlayer O-H-O links is detrimental to in-plane Kitaev exchange since coordination by a single H-ion of the O ligand implies an axial Coulomb potential at the O site and unfavorable polarization of the O 2p orbitals mediating the Ir-Ir interactions. Our results therefore provide valuable guidelines for the rational design of Kitaev quantum magnets, indicating unprecedented Kitaev interactions of ≈40 meV if the linear interlayer linkage is removed.

14.
Biomed Chromatogr ; 32(5): e4176, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29265479

RESUMEN

Fenspiride hydrochloride (FNS) is used in treating chronic inflammatory diseases, most commonly as a liquid oral solution. FNS produces degradation products along with fenspiride N-oxide (FNO) and 1-phenylethyl-4-hydroxy-4-aminomethyl piperidine hydrochloride (PHAP). We aimed to develop and validate a chromatographic method in order to identify the main degradation products in the presence of other compounds from a liquid preparation. The method used a dual gradient using two buffer solutions: the first with pH 4.5 (buffer 1, pH 4.5-MeOH 90:10%, v/v) and the second with pH 2.9 (buffer 2, pH 2.9-acetronitrile-methanol, 65:15:10%, v/v/v). As mentioned, there was a modification of the organic mixture, starting with 10% methanol and ending with a mixture of acetonitrile-methanol (15:10%, v/v). The flow-rate was 1.5 mL/min. According to the elution program, experimental conditions started with 100% solution S1, which decreased to 0% and, simultaneously, solution S2 increased to 100% during the first 10 min and was maintained for a further 5 min. After 15 min, initial conditions were re-established. The linearity interval was 0.5-2 µg/mL and the minimum correlation coefficient was 0.999. The recovery factor was 100.47-103.17% and the limit of quantification was 0.19-0.332 µg/mL. Intra-day maximum precision was 4.08% for FNS and 2.65% for PHAP. This double-gradient mobile phase produced good specificity in relation to the degradation products of FNS and other constituents of the oral liquid formulation. Forced degradation studies revealed other related substances that were confirmed in mass balance analyses. Degradation products were confirmed in acidic, basic and oxidative media.


Asunto(s)
Contaminación de Medicamentos , Compuestos de Espiro/análisis , Compuestos de Espiro/química , Acetonitrilos , Administración Oral , Cromatografía Líquida de Alta Presión/métodos , Cromatografía de Fase Inversa , Formas de Dosificación , Modelos Lineales , Metanol , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
15.
Ecol Evol ; 7(18): 7134-7144, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28944005

RESUMEN

Accurate population size estimates are important information for sustainable wildlife management. The Romanian Carpathians harbor the largest brown bear (Ursus arctos) population in Europe, yet current management relies on estimates of density that lack statistical oversight and ignore uncertainty deriving from track surveys. In this study, we investigate an alternative approach to estimate brown bear density using sign surveys along transects within a novel integration of occupancy models and home range methods. We performed repeated surveys along 2-km segments of forest roads during three distinct seasons: spring 2011, fall-winter 2011, and spring 2012, within three game management units and a Natura 2000 site. We estimated bears abundances along transects using the number of unique tracks observed per survey occasion via N-mixture hierarchical models, which account for imperfect detection. To obtain brown bear densities, we combined these abundances with the effective sampling area of the transects, that is, estimated as a function of the median (± bootstrapped SE) of the core home range (5.58 ± 1.08 km2) based on telemetry data from 17 bears tracked for 1-month periods overlapping our surveys windows. Our analyses yielded average brown bear densities (and 95% confidence intervals) for the three seasons of: 11.5 (7.8-15.3), 11.3 (7.4-15.2), and 12.4 (8.6-16.3) individuals/100 km2. Across game management units, mean densities ranged between 7.5 and 14.8 individuals/100 km2. Our method incorporates multiple sources of uncertainty (e.g., effective sampling area, imperfect detection) to estimate brown bear density, but the inference fundamentally relies on unmarked individuals only. While useful as a temporary approach to monitor brown bears, we urge implementing DNA capture-recapture methods regionally to inform brown bear management and recommend increasing resources for GPS collars to improve estimates of effective sampling area.

16.
Talanta ; 116: 653-62, 2013 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-24148458

RESUMEN

Determination of silver sulfadiazine degradation products in several stress media was carried out by high pressure liquid chromatography (HPLC) with diode array detector (DAD) and hybrid mass spectrometer triple quadrupole-linear trap. The optimal chromatographic method used a Hypercarb column with a stationary phase 100% carbon, a mobile phase composed by a mixture 45:55 formic acid 1% solution and acetonitrile and detection at 275 nm. Structure elucidation was carried out on the mass spectrometry system using same chromatographic conditions and based on MS/MS techniques. Under these conditions up to 9 possible impurities were demonstrated to be degradation products respecting silver sulfadiazine evolution under different stress conditions: temperature, acid, basic, oxidation, reduction and catalyzed photodegradation. Sulfacetamide, sulfanilic acid (4-aminobenzenesulfonic acid), aniline, pyrimidin-2-amine, 4-aminobenzenesulfonamide, 4-methylidenesulfanilaniline, 4-aminophenol, 4-amino-n-methyl benzenesulfonamide and benzenesulfonic acid were identified by mass spectrometry in order to cover the possible degradation paths of silver sulfadiazine. Kinetics were also evaluated to obtain the prediction of shelf life of the substance. The linearity domain for the method was between 0.0005 mg/ml and 0.25mg/ml for each compound. Recovery factors in accuracy determination were between 95 and 105% relative to target concentrations of silver sulfadiazine and the quantitation limit was 0.00025 mg/ml.


Asunto(s)
Aminofenoles/análisis , Antiinfecciosos Locales/química , Bencenosulfonatos/análisis , Sulfadiazina de Plata/química , Calibración , Cromatografía Líquida de Alta Presión , Estabilidad de Medicamentos , Humanos , Concentración de Iones de Hidrógeno , Espectrometría de Masas , Oxidación-Reducción , Fotólisis , Sensibilidad y Especificidad , Temperatura
17.
Org Lett ; 15(17): 4516-9, 2013 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-23947595

RESUMEN

An enantioselective α-hydroxyacetate aldol reaction that employs N-acetyl pyrroles as activated ester equivalents and generates syn 1,2-diols in good yield and diastereoselectivity is reported. This dinuclear zinc-ProPhenol-catalyzed transformation proceeds with high enantioselectivity with a wide variety of substrates including aryl, alyl, and alkenyl aldehydes. The resulting α,ß-dihydroxy activated esters are versatile intermediates for the synthesis of a variety of carboxylic acid derivatives including amides, esters, and unsymmetrical ketones.


Asunto(s)
Alcoholes/química , Aldehídos/química , Cetonas/química , Pirroles/química , Zinc/química , Compuestos Bicíclicos Heterocíclicos con Puentes/síntesis química , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Catálisis , Técnicas Químicas Combinatorias , Ésteres , Cetonas/síntesis química , Lactonas/síntesis química , Lactonas/química , Estructura Molecular , Estereoisomerismo
18.
Brachytherapy ; 11(6): 441-5, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22728157

RESUMEN

PURPOSE: To evaluate the cost-effectiveness and outcomes of low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy compared with intensity-modulated radiation therapy (IMRT) in patients with low/intermediate risk of prostate cancer. METHODS AND MATERIALS: One thousand three hundred twenty-eight patients with low or intermediate risk of prostate cancer were treated with LDR (n=207), HDR with four fractions (n=252), or IMRT (n=869) between January 1992 and December 2008. LDR patients were treated with palladium seeds to a median dose of 120 Gy, whereas HDR patients were treated to a median dose 38.0 Gy (four fractions). IMRT patients received 42-44 fractions with a median dose of 75.6 Gy. Clinical outcomes were compared, including biochemical failure, cause-specific survival, and overall survival. RESULTS: Overall, no differences in 5-year biochemical control (BC) or cause-specific survival were noted among treatment modalities. The calculated reimbursement for LDR brachytherapy, HDR brachytherapy with four fractions, and IMRT was $9,938; $17,514; and $29,356, respectively. HDR and LDR brachytherapy were statistically less costly to Medicare and the institution than IMRT (p<0.001), and LDR brachytherapy was less costly than HDR brachytherapy (p=0.01 and p<0.001). Incremental cost-effectiveness ratios for cost to Medicare for BC with IMRT were $4045 and $2754 per percent of BC for LDR and HDR brachytherapy, respectively. Incremental cost-effectiveness ratio using institutional cost comparing IMRT with LDR and HDR brachytherapy was $4962 and $4824 per 1% improvement in BC. CONCLUSIONS: In this study of patients with low and intermediate risk of prostate cancer, comparable outcomes at 5 years were noted between modalities with increased costs associated with IMRT.


Asunto(s)
Braquiterapia/economía , Braquiterapia/mortalidad , Costos de la Atención en Salud/estadística & datos numéricos , Hospitalización/economía , Neoplasias de la Próstata/economía , Neoplasias de la Próstata/radioterapia , Análisis Costo-Beneficio , Hospitalización/estadística & datos numéricos , Humanos , Masculino , Michigan/epidemiología , Prevalencia , Neoplasias de la Próstata/mortalidad , Análisis de Supervivencia , Tasa de Supervivencia , Resultado del Tratamiento
19.
Eur J Med Res ; 17: 16, 2012 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-22697282

RESUMEN

We report the case of an adult patient recently diagnosed with cirrhosis. The ultrasound evaluation described a multinodular inhomogeneous liver, requiring a magnetic resonance imaging scan for further characterization. The performed magnetic resonance imaging examination confirmed the diagnosis of cirrhosis associated with portal hypertension and detected a vascular left transdiaphragmatic hernia. Although various types of diaphragmatic hernias have been described - congenital or acquired - to the best of our knowledge, this type of pathology has never been reported.


Asunto(s)
Vasos Sanguíneos/patología , Hernia Diafragmática , Cirrosis Hepática , Hernia Diafragmática/complicaciones , Hernia Diafragmática/diagnóstico por imagen , Hernia Diafragmática/patología , Humanos , Hipertensión Portal/patología , Cirrosis Hepática/complicaciones , Cirrosis Hepática/patología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Radiografía
20.
Brachytherapy ; 11(2): 97-104, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-21727032

RESUMEN

PURPOSE: We present 4-year results from a Phase I/II trial using balloon-based brachytherapy to deliver accelerated partial breast irradiation in 2 days. MATERIALS/METHODS: Forty-five patients received breast-conserving surgery followed by adjuvant radiation therapy using a balloon-based brachytherapy applicator delivering 2800 cGy in four fractions over 2 days. Outcomes analyzed include toxicities scored using the NCI Common Toxicity Criteria v3.0 scale, ipsilateral breast tumor recurrence, regional nodal failure, distant metastasis, disease-free survival, cause-specific survival, and overall survival. RESULTS: Median age was 66 years (range, 48-83 years) and median tumor size was 0.6 cm (range, 0.2-2.3 cm). Five percent of patients were node positive (n=2), whereas 73% was estrogen receptor positive (n=33). Median followup was 3.7 years (2.4-7.0 years) with greater than 2 years of followup for all patients. Only Grades 1 and 2 chronic toxicities were noted with fat necrosis (18%) and asymptomatic seromas (42%) being the most common toxicities. Seven percent of patients developed ipsilateral rib fractures (n=3), although this was not statistically associated with maximum rib dose (p=0.31). Ninety-eight percent of patients had a good or excellent radiation-related cosmetic outcome at the time of last followup. There were no ipsilateral breast tumor recurrences or regional nodal failures; however, 2 patients developed distant metastases. Four-year actuarial disease-free survival, cause-specific survival, and overall survival were 96%, 100%, and 93%, respectively. CONCLUSIONS: Treatment of early-stage breast cancer patients with breast-conserving therapy using a 2-day radiation dose schedule resulted in acceptable chronic toxicity and similar clinical outcomes as standard 5-day fractionation.


Asunto(s)
Braquiterapia/métodos , Neoplasias de la Mama/radioterapia , Mama/efectos de la radiación , Fraccionamiento de la Dosis de Radiación , Anciano , Anciano de 80 o más Años , Mama/cirugía , Neoplasias de la Mama/cirugía , Terapia Combinada , Femenino , Humanos , Persona de Mediana Edad
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