Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 124
Filtrar
1.
Sarcoma ; 2022: 2091677, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36046749

RESUMEN

Background: Radiation after resection of an atypical lipomatous tumor (ALT) is controversial. This study evaluates local control and complications after the first resection of ALTs of the extremity with or without adjuvant radiation. Methods: A dual institution, retrospective review of patients treated from 1995 to 2020 with first-time resection of an ALT in the extremity was performed. In total, 102 patients underwent adjuvant radiation (XRT group) and 68 patients were treated with surgery alone (no-XRT group). The median follow-up time was 4.6 years (interquartile range (IQR) 2.0-7.3 years). The median radiation dose was 60 Gy (IQR 55-66 Gy). Univariable and multivariable analyses evaluated the association of patient, tumor, and treatment variables with recurrence and complications. Kaplan-Meier analysis evaluated local recurrence-free survival (LRFS) and time to complication. Results: The overall incidence of local recurrence was 1% (1/102) in the XRT group and 24% (16/68) in the no-XRT group (p < 0.001). The median time-to-recurrence was 8.2 years (IQR 6.5-10.5 years). In the XRT and the no-XRT groups, 5-yr LRFS was 98% and 92% (p=0.21) and 10-yr LRFS was 98% and 41% (p < 0.001), respectively. The absence of radiation (HR = 23.63, 95% CI (3.09-180.48); p < 0.001) and R2 surgical resection margins (HR = 11.04, 95% CI (2.07-59.03); p < 0.001) incurred a 23-fold and 11-fold increased risk of local recurrence, respectively, while tumor size, depth, location, and neurovascular involvement were not found to be independent predictors of recurrence. The complication rate was 37% (38/102) in the XRT group and 10% (7/68) in the no-XRT group (p < 0.001). Eight patients (8/102, 8%) required surgical management for complication in the XRT group compared with two patients (2/68, 3%) in the no-XRT group (p=0.10). Higher radiation dose had a modest correlation with increased severity of complication (ρ=0.24; p=0.02). Conclusions: Adjuvant radiation after first-time resection of an ALT of the extremity was associated with a significantly reduced risk of local recurrence but a three-fold increase in complication rate. These data support a 10-year follow-up for these patients and inform a notable clinical trade-off if considering adjuvant radiation for this tumor with recurrent potential.

2.
J Acoust Soc Am ; 152(1): 601, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35931498

RESUMEN

This paper presents reference equivalent threshold sound pressure levels (RETSPLs) for the Wireless Automated Hearing Test System (WAHTS), a recently commercialized device developed for use as a boothless audiometer. Two initial studies were conducted following the ISO 389-9 standard [ISO 389-9 (2009). "Acoustics-Reference zero for the calibration of audiometric equipment. Part 9: Preferred test conditions for the determinations of reference hearing threshold levels" (International Organization for Standardization, Geneva)]. Although the standard recruitment criteria are intended to yield otologically normal test subjects, the recruited populations appeared to have slightly elevated thresholds [5-10 dB hearing level (HL)]. Comparison of WAHTS thresholds to other clinical audiometric equipment revealed bias errors that were consistent with the elevated thresholds of the RETSPL populations. As the objective of RETSPLs is to ensure consistent thresholds regardless of the equipment, this paper presents the RETSPLs initially obtained following ISO 389-9:2009 and suggested correction to account for the elevated HLs of the originally recruited populations. Two additional independent studies demonstrate the validity of these corrected thresholds.


Asunto(s)
Audiometría , Pruebas Auditivas , Acústica , Audiometría de Tonos Puros , Umbral Auditivo , Humanos , Sonido
3.
Ann Jt ; 7: 24, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-38529133

RESUMEN

Background: The humerus is a common site of metastatic disease that can be fixated with either plate and screw or intramedullary nail (IMN) constructs. A multicenter retrospective comparison study was undertaken to compare implant survival, complication rate and cost between the two constructs. No prior studies have included a cost comparison. Methods: Databases of two academic practices were queried retrospectively to identify patients with metastases of the humerus. Inclusion criteria were a lesion in the proximal metaphysis to distal diaphysis and amenable to both implant options with available cost data. Follow-up was at least 6 months barring death or discharge to hospice sooner. Demographic, clinical and outcome data was recorded. Costs were estimated based on contract pricing. Operating room (OR) costs were estimated using per minute OR costs proposed by other investigators. Results: One hundred and one humeri in 96 patients were included (72 plates and 29 nails). The most common malignancies were renal cell, myeloma and lung. Half presented with a displaced fracture. Demographics were similar in both groups. Lesions were larger in the plate group. Surgical times were longer in the plate group, 146 vs. 75 min, P<0.001. Estimated blood loss (EBL) was higher in the plate group, 510 vs. 221 mL, P<0.001. A trend toward increased failure was seen in the plate group, 12.5% vs. 0% (P=0.056). The most common complications in the plate group were pain, stiffness and swelling compared to pain, refracture and PE in the nail group. Local disease progression was equivalent. Implant costs were higher in the IMN group ($2,753 vs. $1,553, P<0.001), while OR costs were lower ($2,349 vs. $4,395, P<0.001). Overall cost of implantation was lower in the IMN group ($5,102 vs. $5,949, P=0.005). Conclusions: IMN of metastases of the humerus offers a faster, potentially more durable construct with lower blood loss, faster OR times and decreased cost of implantation.

4.
Cancers (Basel) ; 13(9)2021 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-34062962

RESUMEN

Polyploid giant cancer cells (PGCC) constitute a transiently senescent subpopulation of cancer cells that arises in response to stress. PGCC are capable of generating progeny via a primitive, cleavage-like cell division that is dependent on the sphingolipid enzyme acid ceramidase (ASAH1). The goal of this study was to understand differences in sphingolipid metabolism between non-polyploid and polyploid cancer cells to gain an understanding of the ASAH1-dependence in the PGCC population. Steady-state and flux analysis of sphingolipids did not support our initial hypothesis that the ASAH1 product sphingosine is rapidly converted into the pro-survival lipid sphingosine-1-phosphate. Instead, our results suggest that ASAH1 activity is important for preventing the accumulation of long chain ceramides such as C16-ceramide. We therefore determined how modulation of C16-ceramide, either through CerS6 or p53, a known PGCC suppressor and enhancer of CerS6-derived C16-ceramide, affected PGCC progeny formation. Co-expression of the CerS6 and p53 abrogated the ability of PGCC to form offspring, suggesting that the two genes form a positive feedback loop. CerS6 enhanced the effect of p53 by significantly increasing protein half-life. Our results support the idea that sphingolipid metabolism is of functional importance in PGCC and that targeting this signaling pathway has potential for clinical intervention.

5.
Anal Chem ; 93(2): 1050-1058, 2021 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-33302624

RESUMEN

We present a direct comparison between two independent methods for the measurement of gaseous elemental mercury (GEM) mass concentration: isotope dilution cold-vapor inductively coupled plasma mass spectrometry (ID-CV-ICP-MS) and laser absorption spectroscopy (LAS). The former technique combined with passive sorbent tube sampling is currently the primary method at NIST for mercury gas standards traceability to the International System of Units (SI). This traceability is achieved via measurements on a mercury-containing reference material. The latter technique has been recently developed at NIST and involves real-time measurements of light attenuation caused by GEM, with SI traceability based in part on the known spontaneous emission lifetime of the probed 6 1S0-6 3P1 intercombination transition of elemental mercury (Hg0). Using a steady-flow Hg0-in-air generator to produce samples measured by both methods, we use LAS to measure the sample gas and in parallel we collect the Hg0 on sorbent tubes to be subsequently analyzed using ID-CV-ICP-MS. Over the examined mass concentration range (41 µg/m3 to 287 µg/m3 Hg0 in air), the relative disagreement between the two approaches ranged from (1.0 to 1.8)%. The relative combined standard uncertainty on average is 0.4% and 0.9%, for the LAS and MS methods, respectively. Our comparison studies help validate the accuracy of the ID-CV-ICP-MS primary method as well as establish the LAS technique as an attractive alternative primary method for SI-traceable measurements of GEM.


Asunto(s)
Rayos Láser , Mercurio/análisis , Gases/análisis , Espectrometría de Masas , Análisis Espectral
6.
Cytokine ; 135: 155219, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32738771

RESUMEN

The bioactive sphingolipid ceramide affects immune responses although its effect on antigen (Ag) processing and delivery by HLA class II to CD4+T-cells remains unclear. Therefore, we examined the actions of a novel cell-permeable acid ceramidase (AC) inhibitor [(1R,2R) N myristoylamino-(4'-nitrophenyl)-propandiol-1,3] on antigen presentation and inflammatory cytokine production by Ag-presenting cells (APCs) such as B-cells, macrophages, and dendritic cells. We found that AC inhibition in APCs perturbed Ag-processing and presentation via HLA-DR4 (MHC class II) proteins as measured by coculture assay and T-cell production of IL-2. Mass spectral analyses showed that B13 treatment significantly raised levels of four types of ceramides in human B-cells. B13 treatment did not alter Ag internalization and class II protein expression, but significantly inhibited lysosomal cysteinyl cathepsins (B, S and L) and thiol-reductase (GILT), HLA class II Ag-processing, and generation of functional class II-peptide complexes. Ex vivo Ag presentation assays showed that inhibition of AC impaired primary and recall CD4+T-cell responses and cytokine production in response against type II collagen. Further, B13 delayed onset and reduced severity of inflamed joints and cytokine production in the collagen-induced arthritis mouse model in vivo. These findings suggest that inhibition of AC in APCs may dysregulate endolysosomal proteases and HLA class II-associated self-antigen presentation to CD4+T-cells, attenuating inflammatory cytokine production and suppressing host autoimmune responses.


Asunto(s)
Ceramidasa Ácida/inmunología , Presentación de Antígeno/inmunología , Artritis Experimental/inmunología , Enfermedades Autoinmunes/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Animales , Células Presentadoras de Antígenos/inmunología , Linfocitos B/inmunología , Linfocitos T CD4-Positivos/inmunología , Catepsinas/inmunología , Línea Celular , Antígeno HLA-DR4/inmunología , Humanos , Macrófagos/inmunología , Ratones , Ratones Endogámicos DBA
7.
Sci Rep ; 10(1): 9223, 2020 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-32514049

RESUMEN

Cancer cells differ in size from those of their host tissue and are known to change in size during the processes of cell death. A noninvasive method for monitoring cell size would be highly advantageous as a potential biomarker of malignancy and early therapeutic response. This need is particularly acute in brain tumours where biopsy is a highly invasive procedure. Here, diffusion MRI data were acquired in a GL261 glioma mouse model before and during treatment with Temozolomide. The biophysical model VERDICT (Vascular Extracellular and Restricted Diffusion for Cytometry in Tumours) was applied to the MRI data to quantify multi-compartmental parameters connected to the underlying tissue microstructure, which could potentially be useful clinical biomarkers. These parameters were compared to ADC and kurtosis diffusion models, and, measures from histology and optical projection tomography. MRI data was also acquired in patients to assess the feasibility of applying VERDICT in a range of different glioma subtypes. In the GL261 gliomas, cellular changes were detected according to the VERDICT model in advance of gross tumour volume changes as well as ADC and kurtosis models. VERDICT parameters in glioblastoma patients were most consistent with the GL261 mouse model, whilst displaying additional regions of localised tissue heterogeneity. The present VERDICT model was less appropriate for modelling more diffuse astrocytomas and oligodendrogliomas, but could be tuned to improve the representation of these tumour types. Biophysical modelling of the diffusion MRI signal permits monitoring of brain tumours without invasive intervention. VERDICT responds to microstructural changes induced by chemotherapy, is feasible within clinical scan times and could provide useful biomarkers of treatment response.


Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética , Glioma/diagnóstico por imagen , Animales , Antineoplásicos Alquilantes/farmacología , Antineoplásicos Alquilantes/uso terapéutico , Astrocitoma/diagnóstico por imagen , Astrocitoma/patología , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Femenino , Glioma/tratamiento farmacológico , Glioma/patología , Humanos , Procesamiento de Imagen Asistido por Computador , Ratones , Ratones Endogámicos C57BL , Clasificación del Tumor , Oligodendroglioma/diagnóstico por imagen , Oligodendroglioma/patología , Temozolomida/farmacología , Temozolomida/uso terapéutico , Trasplante Heterólogo , Carga Tumoral/efectos de los fármacos
8.
PLoS One ; 15(3): e0230348, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32182279

RESUMEN

Before Europeans arrived to Eastern North America, prehistoric, indigenous peoples experienced a number of changes that culminated in the development of sedentary, maize agricultural lifeways of varying complexity. Inherent to these lifeways were several triggers of social stress including population nucleation and increase, intergroup conflict (warfare), and increased territoriality. Here, we examine whether this period of social stress co-varied with deadlier weaponry, specifically, the design of the most commonly found prehistoric archery component in late pre-contact North America: triangular stone arrow tips (TSAT). The examination of modern metal or carbon projectiles, arrows, and arrowheads has demonstrated that smaller arrow tips penetrate deeper into a target than do larger ones. We first experimentally confirm that this relationship applies to arrow tips made from stone hafted onto shafts made from wood. We then statistically assess a large sample (n = 742) of late pre-contact TSAT and show that these specimens are extraordinarily small. Thus, by miniaturizing their arrow tips, prehistoric people in Eastern North America optimized their projectile weaponry for maximum penetration and killing power in warfare and hunting. Finally, we verify that these functional advantages were selected across environmental and cultural boundaries. Thus, while we cannot and should not rule out stochastic, production economizing, or non-adaptive cultural processes as an explanation for TSAT, overall our results are consistent with the hypothesis that broad, socially stressful demographic changes in late pre-contact Eastern North America resulted in the miniaturization-and augmented lethality-of stone tools across the region.


Asunto(s)
Indígenas Norteamericanos/historia , Miniaturización , Factores Sociológicos , Guerra/historia , Armas/historia , Arqueología , Historia Antigua , Humanos , Indígenas Norteamericanos/psicología , América del Norte , Crecimiento Demográfico , Guerra/psicología
9.
Chem Commun (Camb) ; 56(32): 4476-4479, 2020 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-32201871

RESUMEN

We have identified a proteolysis targeting chimera (PROTAC) of class I HDACs 1, 2 and 3. The most active degrader consists of a benzamide HDAC inhibitor, an alkyl linker, and the von Hippel-Lindau E3 ligand. Our PROTAC increased histone acetylation levels and compromised colon cancer HCT116 cell viability, establishing a degradation strategy as an alternative to class I HDAC inhibition.


Asunto(s)
Proteínas Co-Represoras , Histona Desacetilasas , Animales , Humanos , Ratones , Antineoplásicos/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Proteínas Co-Represoras/metabolismo , Histona Desacetilasa 1/antagonistas & inhibidores , Inhibidores de Histona Desacetilasas/química , Inhibidores de Histona Desacetilasas/farmacología , Histona Desacetilasas/metabolismo , Histona Demetilasas/antagonistas & inhibidores , Proteolisis
10.
Cancer Med ; 9(9): 3142-3152, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32135040

RESUMEN

Polyploid giant cancer cells (PGCC) represent a poorly understood, small subpopulation of tumor cells that are increasingly being recognized for their critical role in therapy resistance, metastasis, and cancer recurrence. PGCC have the potential to generate progeny through primitive or cleavage-like division, which allows them to evade antimitotic insults. We recently demonstrated that the sphingolipid enzyme acid ceramidase (ASAH1) is required for this process. Since specific ASAH1 inhibitors are not clinically available, we investigated whether tamoxifen, which interferes with ASAH1 function via off-target effects, has a potential clinical benefit independent of estrogen signaling. Our results show that tamoxifen inhibits generation of PGCC offspring in prostate cancer, glioblastoma, and melanoma cells. Analysis of two state-level cancer registries revealed that tamoxifen improves survival outcomes for second, nonbreast cancers that develop in women with early stage breast cancer. Our results suggest that tamoxifen may have a clinical benefit in a variety of cancers that is independent of estrogen signaling and could be due to its inhibition of acid ceramidase. Thus the distinct application of tamoxifen as potentially a first-in-class therapeutic that inhibits the generation of PGCC offspring should be considered in future clinical trials.


Asunto(s)
Ceramidasa Ácida/antagonistas & inhibidores , Antineoplásicos Hormonales/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Tamoxifeno/farmacología , Apoptosis , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Ciclo Celular , División Celular , Proliferación Celular , Femenino , Humanos , Persona de Mediana Edad , Pronóstico , Tasa de Supervivencia , Células Tumorales Cultivadas
11.
Magn Reson Med ; 84(3): 1543-1551, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32060975

RESUMEN

INTRODUCTION: To combine numerical simulations, in vitro and in vivo experiments to evaluate the feasibility of measuring diffusion exchange across the cell membrane with diffusion exchange spectroscopy (DEXSY). METHODS: DEXSY acquisitions were simulated over a range of permeabilities in nerve tissue and yeast substrates. In vitro measurements were performed in a yeast substrate and in vivo measurements in mouse tumor xenograft models, all at 9.4 T. RESULTS: Diffusion exchange was observed in simulations over a physiologically relevant range of cell permeability values. In vitro and in vivo measures also provided evidence of diffusion exchange, which was quantified with the Diffusion Exchange Index (DEI). CONCLUSIONS: Our findings provide preliminary evidence that DEXSY can be used to make in vivo measurements of diffusion exchange and cell membrane permeability.


Asunto(s)
Modelos Teóricos , Animales , Membrana Celular , Permeabilidad de la Membrana Celular , Difusión , Ratones , Permeabilidad , Análisis Espectral
12.
Int J Audiol ; 59(sup1): S12-S19, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31846397

RESUMEN

Objective: The recent emphasis on outcomes-based medical research has motivated a need for technology that allows researchers and clinicians to reach a larger and more diverse subject population for recruitment and testing.Design: This article reports on open-source mobile software (TabSINT) that enables researchers to administer customised hearing tests and questionnaires on tablets located across multiple sites. Researchers create and modify test protocols using text-based templates and deploy it to the tablets via a cloud-based repository or USB-computer connection. Results are exported locally to the tablet SD card and can also be automatically posted to a cloud-based database.Results: Between 2014 and 2019, TabSINT collected 25,000+ test results using more than 200+ unique test protocols for researchers located worldwide.Conclusions:TabSINT is a powerful software system with the potential to greatly enhance research across multiple disciplines by enabling access to subject cohorts in remote and disparate locations. Released open-source, this software is available to researchers across the world to use and adapt to their specific needs. Researchers with engineering resources can contribute to the repository to extend the capability and robustness of this software.


Asunto(s)
Audiología , Investigación Biomédica/métodos , Aplicaciones de la Informática Médica , Programas Informáticos , Sistemas de Administración de Bases de Datos , Audición , Humanos , Internet , Diseño de Software
13.
Int J Surg Oncol ; 2020: 8374790, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33489372

RESUMEN

INTRODUCTION: Inadvertent excision of a soft tissue sarcoma during hernia surgery is a preventable clinical scenario that leads to unnecessary patient morbidity. Prior series are few, which only include male patients with little focus on prevention. The purpose of this study is to report the presenting features and outcomes of both male and female patients who underwent inadvertent inguinal sarcoma excision during hernia surgery. METHODS: A retrospective analysis of a single sarcoma referral center identified 33 patients who were referred for definitive treatment. Patients were divided into three clinically relevant groups based on intraoperative diagnosis, sex, and location of the mass relative to the inguinal ligament. T-tests and Fisher's exact tests were performed to compare continuous and categorical variables, respectively. Kaplan-Meier modeling was performed to assess sarcoma-specific survival. RESULTS: Females were younger (47 years vs. 61 years, p=0.003) and had smaller sarcomas (6.7 cm vs. 11 cm, p=0.012) compared to males. Only two sarcomas (2/33, 6%) were <4 cm in size. The majority of sarcomas in females were above the inguinal ligament (12/14, 86%). Twenty-nine (88%) underwent definitive R0 excision. The mean number of surgeries per patient was three (range 1-13), with nineteen (58%) patients requiring flap reconstruction and six (18%) requiring vascular bypass. Five patients locally recurred (15%) at a mean of 38 months after definitive excision (range 5-128 months). Overall sarcoma-specific disease-free survival was 64%, with no difference between males (80 ± 11%) and females (59 ± 17%) (p=0.885). Mean follow-up was 75 months (range 5-212). CONCLUSION: This is the second largest study regarding inadvertent inguinal sarcoma excision and the first to include females. When a suspected hernia is >4 cm, irreducible, firm, and is growing, especially in females, consider obtaining preoperative advanced three-dimensional imaging (CT or MRI) that can differentiate a neoplasm from a hernia.


Asunto(s)
Hernia Inguinal/diagnóstico , Recurrencia Local de Neoplasia , Sarcoma/diagnóstico , Sarcoma/cirugía , Neoplasias de los Tejidos Blandos/diagnóstico , Neoplasias de los Tejidos Blandos/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Errores Diagnósticos , Supervivencia sin Enfermedad , Femenino , Hernia Inguinal/cirugía , Humanos , Hallazgos Incidentales , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Reoperación , Estudios Retrospectivos , Sarcoma/patología , Neoplasias de los Tejidos Blandos/patología , Tasa de Supervivencia , Carga Tumoral , Adulto Joven
14.
Molecules ; 24(18)2019 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-31514464

RESUMEN

Antibiotic resistance is a global health concern and a current threat to modern medicine and society. New strategies for antibiotic drug design and delivery offer a glimmer of hope in a currently limited pipeline of new antibiotics. One strategy involves conjugating iron-chelating microbial siderophores to an antibiotic or antimicrobial agent to enhance uptake and antibacterial potency. Cefiderocol (S-649266) is a promising cephalosporin-catechol conjugate currently in phase III clinical trials that utilizes iron-mediated active transport and demonstrates enhanced potency against multi-drug resistant (MDR) Gram-negative pathogens. Such molecules demonstrate that siderophore-antibiotic conjugates could be important future medicines to add to our antibiotic arsenal. This review is written in the context of the chemical design of siderophore-antibiotic conjugates focusing on the differing siderophore, linker, and antibiotic components that make up conjugates. We selected chemically distinct siderophore-antibiotic conjugates as exemplary conjugates, rather than multiple analogues, to highlight findings to date. The review should offer a general guide to the uninitiated in the molecular design of siderophore-antibiotic conjugates.


Asunto(s)
Antibacterianos/farmacología , Diseño de Fármacos , Sideróforos/farmacología , Antibacterianos/síntesis química , Antibacterianos/química , Ensayos Clínicos como Asunto , Compuestos Ferrosos/química , Compuestos Ferrosos/farmacología , Humanos , Péptidos/química , Péptidos/farmacología , Sideróforos/síntesis química , Sideróforos/química
15.
J Lipid Res ; 60(7): 1225-1235, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30988134

RESUMEN

Radiation treatment failure or relapse after initial response to chemotherapy presents significant clinical challenges in cancer patients. Escape from initial courses of treatment can involve reactivation of embryonic developmental stages, with the formation of polynuclear giant cancer cells (PGCCs). This strategy of dedifferentiation can insulate cancer cells from a variety of treatments and allows a residual subpopulation to reestablish tumors after treatment. Using radiation or docetaxel chemotherapy, we generated PGCCs from prostate cancer cells. Here, we show that expression of acid ceramidase (ASAH1), an enzyme in the sphingolipid pathway linked to therapy resistance and poor outcomes, is elevated in PGCCs. Targeting ASAH1 with shRNA or treatment with the ASAH1 inhibitor, LCL-521, did not impair the formation of PGCCs, but prevented the formation of PGCC progeny that arise through an asymmetric cell division called neosis. Similar results were obtained in lung cancer cells that had been exposed to radiation or cisplatin chemotherapy as stressors. In summary, our data suggest that endoreplication occurs independent of ASAH1 while neosis is ASAH1-dependent in both prostate and lung cancer cells. Because ASAH1 knockout is embryonic lethal but not deleterious to adult animals, targeting this enzyme has the potential to be highly specific to cells undergoing the dedifferentiation process to escape cancer treatments. Pharmacological inhibition of ASAH1 is a potentially powerful strategy to eliminate cells that could otherwise serve as seed populations for recurrence.


Asunto(s)
Ceramidasa Ácida/antagonistas & inhibidores , Ceramidasa Ácida/metabolismo , Ceramidas/metabolismo , Esfingolípidos/metabolismo , Células A549 , Ceramidasa Ácida/genética , Apoptosis/efectos de los fármacos , Western Blotting , División Celular/efectos de los fármacos , Línea Celular Tumoral , Cisplatino/farmacología , Docetaxel/farmacología , Citometría de Flujo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Lipidómica/métodos , ARN Interferente Pequeño/metabolismo
16.
J Phycol ; 55(3): 611-624, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30805921

RESUMEN

Lobophora is a common tropical to temperate genus of brown algae found in a plethora of habitats including shallow and deep-water coral reefs, rocky shores, mangroves, seagrass beds, and rhodoliths beds. Recent molecular studies have revealed that Lobophora species diversity has been severely underestimated. Current estimates of the species numbers range from 100 to 140 species with a suggested center of diversity in the Central Indo-Pacific. This study used three molecular markers (cox3, rbcL, psbA), different single-marker species delimitation methods (GMYC, ABGD, PTP), and morphological evidence to evaluate Lobophora species diversity in the Western Atlantic and the Eastern Pacific oceans. Cox3 provided the greatest number of primary species hypotheses(PSH), followed by rbcL and then psbA. GMYC species delimitation analysis was the most conservative across all three markers, followed by PTP, and then ABGD. The most informative diagnostic morphological characters were thallus thickness and number of cell layers in both the medulla and the dorsal/ventral cortices. Following a consensus approach, 14 distinct Lobophora species were identified in the Western Atlantic and five in the Eastern Pacific. Eight new species from these two oceans were herein described: L. adpressa sp. nov., L. cocoensis sp. nov., L. colombiana sp. nov., L. crispata sp. nov., L. delicata sp. nov., L. dispersa sp. nov., L. panamensis sp. nov., and L. tortugensis sp. nov. This study showed that the best approach to confidently identify Lobophora species is to analyze DNA sequences (preferably cox3 and rbcL) followed by comparative morphological and geographical assessment.


Asunto(s)
Phaeophyceae , Arrecifes de Coral , Geografía , Océano Pacífico , Filogenia
17.
Beilstein J Org Chem ; 14: 2646-2650, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30410626

RESUMEN

Siderophore-antibiotic conjugates consist of an antibiotic covalently linked by a tether to a siderophore. Such conjugates can demonstrate enhanced uptake and internalisation to the bacterial cell resulting in significantly reduced MIC values and extended spectrum of activity. Phenothiazines are a class of small molecules that have been identified as a potential treatment for multidrug resistant tuberculosis and latent TB. Herein we report the design and synthesis of the first phenothiazine-siderophore conjugate. A convergent synthetic route was developed whereby the functionalised phenothiazine component was prepared in four steps and the siderophore component also prepared in four steps. In M. smegmatis the functionalised phenothiazine demonstrated an equipotent MIC value in direct comparison to the parent phenothiazine from which it was derived. The final conjugate was synthesised by amide bond formation between the two components and global deprotection of the PMB protecting groups to unmask the catechol iron chelating groups of the siderophore. The synthesis is readily amenable to the preparation of analogues whereby the siderophore component of the conjugate can be modified. The route will be used to prepare a library of siderophore-phenothiazine conjugates for full biological evaluation of much needed new antibacterial agents.

18.
BMC Palliat Care ; 17(1): 118, 2018 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-30340632

RESUMEN

BACKGROUND: A national Do Not Attempt Cardiopulmonary Resuscitation policy was rolled out for the National Health Service in Wales in 2015. A national steering group led on producing information videos and a website for patients, carers and healthcare professionals, forming part of a quality improvement program. Videos were planned, scripted and produced with healthcare professionals and patient/carer representatives, and were completed with both English and Welsh language versions. The TalkCPR videos encourage and promote open discussion about Cardiopulmonary Resuscitation (CPR) and DNACPR in palliative care situations. METHODS: We worked with patient/carer groups to evaluate whether video resources to convey the salient facts involved in CPR and DNACPR decisions for people with palliative and life-limiting illness were acceptable or not. We conducted a mixed-method design service review in five phases to evaluate whether this technological resource could help. After creating video and website materials, they were evaluated by doctors, nurses and a patient/carer group. We also sent out one lightweight TalkCPR video media pad to each practice in Wales. These rechargeable electronic video media pads had communication videos pre-loaded for easy viewing, especially in areas with poor roaming data coverage. RESULTS: Videos were demonstrably acceptable to both patient and carer groups, and improved healthcare professional confidence and understanding. Videos went live on the TalkCPR website, in all Welsh Health Boards and on Youtube, and are now used in routine practice throughout Wales. CONCLUSION: This is the first time that DNACPR information videos are aimed directly at palliative care patients and carers, to explore this sensitive subject with them, and to encourage them to approach their doctor or nurse about it. The website, app and video media pads were developed by patients, the Digital Legacy Association, Welsh NHS IT services, Welsh Government, the Bevan Commission and the Dying Matters Charity in Wales 'Byw Nawr'. The GMC, the Royal College of General Practitioners and NICE have listed TalkCPR as a learning resource. There has also been a collaboration with Falmouth University Art College, who helped produce graphic designs to facilitate and encourage discussions about CPR and end of life care.


Asunto(s)
Reanimación Cardiopulmonar , Cuidados Paliativos , Órdenes de Resucitación , Cuidado Terminal , Reanimación Cardiopulmonar/psicología , Toma de Decisiones , Política de Salud , Investigación sobre Servicios de Salud , Humanos , Consentimiento Informado , Educación del Paciente como Asunto , Órdenes de Resucitación/psicología , Cuidado Terminal/psicología , Grabación en Video , Gales
19.
Adv Cancer Res ; 140: 265-293, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30060812

RESUMEN

Sphingolipid metabolism is known to play a role in cell death, survival, and therapy resistance in cancer. Sphingolipids, particularly dihydroceramide and ceramide, are associated with antiproliferative or cell death responses, respectively, and are central to effective cancer therapy. Within the last decade, strides have been made in elucidating many intricacies of sphingolipid metabolism. New information has emerged on the mechanisms by which sphingolipid metabolism is dysregulated during malignancy and how cancer cells survive and/or escape therapeutic interventions. This chapter focuses on three main themes: (1) sphingolipid enzymes that are dysregulated in cancer, particularly in prostate cancer; (2) inhibitors of sphingolipid metabolism that antagonize prosurvival responses; and (3) sphingolipid-driven escape mechanisms that allow cancer cells to evade therapies. We explore clinical and preclinical approaches to interdict sphingolipid metabolism and provide a rationale for combining strategies to drive the generation of antiproliferative ceramides with prevention of ceramide clearance.


Asunto(s)
Antineoplásicos/uso terapéutico , Metabolismo de los Lípidos/efectos de los fármacos , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/fisiopatología , Esfingolípidos/metabolismo , Animales , Humanos , Masculino , Neoplasias de la Próstata/metabolismo
20.
Anal Chem ; 90(7): 4711-4718, 2018 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-29498261

RESUMEN

There are many gas phase compounds present in the atmosphere that affect and influence the earth's climate. These compounds absorb and emit radiation, a process which is the fundamental cause of the greenhouse effect. The major greenhouse gases in the earth's atmosphere are carbon dioxide, methane, nitrous oxide, and ozone. Some halocarbons are also strong greenhouse gases and are linked to stratospheric ozone depletion. Hydrocarbons and monoterpenes are precursors and contributors to atmospheric photochemical processes, which lead to the formation of particulates and secondary photo-oxidants such as ozone, leading to photochemical smog. Reactive gases such as nitric oxide and sulfur dioxide are also compounds found in the atmosphere and generally lead to the formation of other oxides. These compounds can be oxidized in the air to acidic and corrosive gases and contribute to photochemical smog. Measurements of these compounds in the atmosphere have been ongoing for decades to track growth rates and assist in curbing emissions of these compounds into the atmosphere. To accurately establish mole fraction trends and assess the role of these gas phase compounds in atmospheric chemistry, it is essential to have good calibration standards. The National Institute of Standards and Technology has been developing standards of many of these compounds for over 40 years. This paper discusses the development of these standards.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA