RESUMEN
Melanoma is the most aggressive form of skin cancer with an estimated 106,110 newly diagnosed cases in the United States of America in 2021 leading to an approximated 7180 melanoma-induced deaths. Cancer typically arises from an accumulation of somatic mutations and can be associated with mutagenic or carcinogenic exposure. A key characteristic of melanoma is the extensive somatic mutation rate of 16.8 mutations/Mb, which is largely attributed to UV exposure. Bearing the highest mutational load, many of them occur in key driver pathways, most commonly the BRAFV600E in the mitogen-activated protein kinase (MAPK) pathway. This driver mutation is targeted clinically with FDA-approved therapies using small molecule inhibitors of oncogenic BRAFV600E and MEK, which has greatly expanded therapeutic intervention following a melanoma diagnosis. Up until 2011, therapeutic options for metastatic melanoma were limited, and treatment typically fell under the spectrum of surgery, radiotherapy, and chemotherapy.Attributed to the extensive mutation rate, as well as having the highest number of neoepitopes, melanoma is deemed to be extremely immunogenic. However, despite this highly immunogenic nature, melanoma is notorious for inducing an immunosuppressive microenvironment which can be relieved by checkpoint inhibitor therapy. The two molecules currently approved clinically are ipilimumab and nivolumab, which target the molecules CTLA-4 and PD-1, respectively.A plethora of immunomodulatory molecules exist, many with redundant functions. Additionally, these molecules are expressed not only by immune cells but also by tumor cells within the tumor microenvironment. Tumor profiling of these cell surface checkpoint molecules is necessary to optimize a clinical response. The presence of immunomodulatory molecules in melanoma, using data from The Cancer Genome Atlas and validation of expression in two model systems, human melanoma tissues and patient-derived melanoma cells, revealed that the expression levels of B and T lymphocyte attenuator (BTLA), TIM1, and CD226, concurrently with the BRAFV600E mutation status, significantly dictated overall survival in melanoma patients. These molecules, along with herpesvirus entry mediator (HVEM) and CD160, two molecules that are a part of the HVEM/BTLA/CD160 axis, had a higher expression in human melanoma tissues when compared to normal skin melanocytes and have unique roles to play in T cell activation. New links are being uncovered between the expression of immunomodulatory molecules and the BRAFV600E genetic lesion in melanoma. Small molecule inhibitors of the MAPK pathway regulate the surface expression of this multifaceted molecule, making BTLA a promising target for immuno-oncology to be targeted in combination with small molecule inhibitors, potentially alleviating T regulatory cell activation and improving patient prognosis.
Asunto(s)
Melanoma , Neoplasias Cutáneas , Humanos , Ipilimumab , Melanoma/tratamiento farmacológico , Melanoma/genética , Oncogenes , Proteínas Proto-Oncogénicas B-raf , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/genética , Microambiente TumoralRESUMEN
Two-dimensional (2-D) gel electrophoresis currently represents one of the most standard techniques for protein separation. In addition to the most commonly employed polyacrylamide crosslinked hydrogels, acrylamide-agarose copolymers have been proposed as promising systems for separation matrices in 2-D electrophoresis, because of the good resolution of both high and low molecular mass proteins made possible by careful control and optimization of the hydrogel pore structure. As a matter of fact, a thorough understanding of the nature of the hydrogel pore structure as well as of the parameters by which it is influenced is crucial for the design of hydrogel systems with optimal sieving properties. In this work, a series of acrylamide-based hydrogels covalently crosslinked with different concentrations of allyl agarose (0.2-1%) is prepared and characterized by creep-recovery measurements, dynamic rheology and tensile tests, in the attempt to gain a clearer understanding of structure-property relationships in crosslinked polyacrylamide-based hydrogels. The rheological and mechanical properties of crosslinked acrylamide-agarose hydrogels are found to be greatly affected by crosslinker concentration. Dynamic rheological tests show that hydrogels with a percentage of allyl agarose between 0.2% and 0.6% have a low density of elastically effective crosslinks, explaining the good separation of high molecular mass proteins in 2-D gel electrophoresis. Over the same range of crosslinker concentration, creep-recovery measurements reveal the presence of non-permanent crosslinks in the hydrogel network that justifies the good resolution of low molecular mass proteins as well. In tensile tests, the hydrogel crosslinked with 0.4% of allyl agarose exhibits the best results in terms of mechanical strength and toughness. Our results show how the control of the viscoelastic and the mechanical properties of these materials allow the design of mechanically stable hydrogels with improved sieving ability in protein electrophoresis over a wide range of molecular masses.
Asunto(s)
Resinas Acrílicas/química , Electroforesis en Gel Bidimensional/métodos , Fenómenos Mecánicos , Reología , Sefarosa/química , Ensayo de Materiales , Resistencia a la TracciónRESUMEN
Estrogen aids in neo-vascularization of various tumors during hypoxic conditions, however the role of estrogen within the hypoxic environment of thyroid cancer is not known. In a series of experimentations, using human thyroid cancer cells, we observed that estrogen and hypoxia modulate the hypoxia inducible factor-1 (HIF-1) signaling which is abrogated by the anti-estrogen fulvestrant and the HIF-1 inhibitor YC-1 (3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole). Furthermore, we found that the conditioned medium from estrogen treated thyroid cancer cells lead to enhanced migration and tubulogenesis of human umbilical vein endothelial cells (HUVECs) which is abrogated by HIF-1 inhibitor. These findings, in addition to our previous and other scientific literature data, lead us to conclude that estrogen and hypoxia are interlinked in thyroid cancer and can equally modulate epithelial-endothelial cell interactions by mediating key cellular, metabolic and molecular processes of thyroid cancer progression. We believe that the hormonal component and cellular adaptation to oxygen tension of cancer cells are functionally equivalent with a cellular transition that can be exploited clinically for a combinational approach for thyroid cancer treatment involving antiestrogens as well as anti-hypoxic agents.
Asunto(s)
Estrógenos/metabolismo , Hipoxia/metabolismo , Neoplasias de la Tiroides/metabolismo , Animales , Antineoplásicos/uso terapéutico , Progresión de la Enfermedad , Moduladores de los Receptores de Estrógeno/uso terapéutico , Humanos , Neoplasias de la Tiroides/tratamiento farmacológico , Neoplasias de la Tiroides/patologíaRESUMEN
PURPOSE: In this study, the effects of variable and constant-intensity cycling on muscle glycogen depletion patterns and subsequent running economy was examined. 60 minutes of cycling at a constant power (CON) or variable intensity (VAR) followed by a treadmill run to determine running economy was completed by nine male triathletes (Vo(2)max = 67.7 (4.9 ml) kg(-) min(-1)). During CON, there was greater glycogen depletion in the type I fibres compared with type II (0.08 (0.04) vs 0.02 (0.01) optical density (OD) units; p<0.05), while during VAR, there was greater glycogen depletion in the type II fibres compared with type I (0.06 (0.03) vs 0.03 (0.02) OD; p<0.05). The variation in muscle glycogen depletion patterns was not associated with the detriment in running economy, which was not significantly different between conditions (52.1 vs 52.8 ml kg(-1) min(-1)). There was a strong correlation between total muscle glycogen depletion and the change in running Vo(2) (r = 0.73, p<0.05) when the data from both trials were combined. There was also a negative correlation between type I fibre percentage and glycogen depletion within type II fibres during CON (r = -0.85, p<0.05). The results demonstrate that the decrease in running economy, subsequent to 60 minutes of cycling, is not affected by the cycling strategy employed. While different glycogen depletion patterns in the type I and II fibres were observed between conditions, total glycogen depletion may be more important to subsequent running economy. The percentage of type I fibres was associated with the glycogen depletion pattern during constant load, but not variable-intensity exercise.
Asunto(s)
Glucógeno/metabolismo , Carrera/fisiología , Adulto , Prueba de Esfuerzo , Humanos , Lactatos/metabolismo , Masculino , Fibras Musculares Esqueléticas , Consumo de Oxígeno/fisiología , Resistencia Física/fisiologíaRESUMEN
Triathlons of all distances can be considered endurance events and consist of the individual disciplines of swimming, cycling and running which are generally completed in this sequential order. While it is expected that elite triathletes would possess high values for submaximal and maximal measures of aerobic fitness, little is known about how these values compare with those of single-sport endurance athletes. Earlier reviews, conducted in the 1980s, concluded that triathletes possessed lower V(O2(max)) values than other endurance athletes. An update of comparisons is of interest to determine if the physiological capacities of elite triathletes now reflect those of single-sport athletes or whether these physiological capacities are compromised by the requirement to cross-train for three different disciplines. It was found that although differences in the physiological attributes during swimming, cycling and running are evident among triathletes, those who compete at an international level possess V(O2(max)) values that are indicative of success in endurance-based individual sports. Furthermore, various physiological parameters at submaximal workloads have been used to describe the capacities of these athletes. Only a few studies have reported the lactate threshold among triathletes with the majority of studies reporting the ventilatory threshold. Although observed differences among triathletes for both these submaximal measures are complicated by the various methods used to determine them, the reported values for triathletes are similar to those for trained cyclists and runners. Thus, from the limited data available, it appears that triathletes are able to obtain similar physiological values as single-sport athletes despite dividing their training time among three disciplines.
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Ciclismo/fisiología , Resistencia Física/fisiología , Aptitud Física/fisiología , Carrera/fisiología , Deportes , Natación/fisiología , Adolescente , Adulto , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
OBJECTIVE: To evaluate the influences of different doses of daily oral unopposed 17beta-estradiol compared with placebo, both on glucose tolerance and lipid metabolism in healthy postmenopausal women. PATIENTS AND METHODS: Forty-eight normoinsulinemic postmenopausal women were enrolled in the study. Patients were assigned to receive randomly 1 mg (group A) or 2 mg (group B) of oral micronized estradiol therapy daily or to the placebo (group C), for 12 weeks. RESULTS: The low-dose estradiol treatment determined an improvement of the peripheral insulin sensitivity, made evident by a significant increase both in the metabolic index and oral glucose insulin sensitivity index (p < 0.01 and p < 0.05, respectively) as well as a decrease in the homeostasis model assessment-estimated insulin resistance (p < 0.01). Conversely, in the standard-dose group, the metabolic index significantly decreased (p < 0.05), showing a slight deterioration in insulin sensitivity. For lipid metabolism, the 1 mg dose showed a neutral effect, while 2 mg had a beneficial effect on low density lipoprotein cholesterol, but caused an increase in triglycerides (p < 0.01 and p < 0.05, respectively). CONCLUSIONS: The oral low dose of unopposed estradiol therapy had a favorable effect on glycoinsulinemic metabolism in healthy postmenopausal women; however, the standard dose caused a slight but significant deterioration in insulin sensitivity.
Asunto(s)
Estradiol/análogos & derivados , Terapia de Reemplazo de Estrógeno , Insulina/sangre , Metabolismo de los Lípidos/efectos de los fármacos , Salud de la Mujer , Glucemia/efectos de los fármacos , Metabolismo de los Hidratos de Carbono/efectos de los fármacos , LDL-Colesterol/sangre , Relación Dosis-Respuesta a Droga , Estradiol/administración & dosificación , Estradiol/farmacología , Femenino , Humanos , Italia , Persona de Mediana Edad , Valores de Referencia , Triglicéridos/sangreRESUMEN
The aim of this study was to investigate the effect of constant versus variable power output cycling exercise on subsequent high-intensity, running performance. Eight triathletes completed two testing sessions (in a random order), which required the subjects to perform 30 min of cycling at either, a constant power output (90% of the lactate threshold), or a variable power output with power output alternating every 5 min (+/-20% of the constant workload). Each cycling bout was immediately followed by a high-intensity treadmill run (16.7+/-0.7 km h(-1)) to exhaustion. No significant differences were found for mean metabolic values or power output between cycling conditions. However, a significant (P<0.05) improvement in run time to exhaustion was reported after 30 min of variable cycling (15:09+/-4:43 min) compared to constant cycling (10:51+/-3:32 min). The results of this study demonstrate that, despite similar average physiological responses during 30 min of cycling, variable-intensity cycling results in an improved running performance compared to constant-intensity cycling. It is hypothesised that the reduced power output in the final 5 min of variable cycling protocol may allow recovery before transition, however the mechanisms involved cannot be determined from the current study.
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Ciclismo/fisiología , Metabolismo Energético/fisiología , Ejercicio Físico/fisiología , Carrera/fisiología , Adulto , Prueba de Esfuerzo , Humanos , Masculino , Factores de TiempoRESUMEN
Biomarkers for thyroid cancer (TCa) lack specificity. To develop TCa specific biomarkers, SELDI-TOF-MS was used to examine the proteomic profile of biopsies obtained from papillary TCa along with adjacent normal tissue. Sixty-three potential biomarkers were categorized by univariate analysis into single biomarker candidates and segregated by multivariate analysis into normal and cancerous groups. Our studies demonstrate the sensitivity and reproducibility of this approach to detect biomarkers for TCa.
Asunto(s)
Biomarcadores de Tumor , Análisis por Matrices de Proteínas , Proteómica/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Neoplasias de la Tiroides/diagnóstico , Carcinoma Papilar/diagnóstico , Carcinoma Papilar/patología , Humanos , Análisis Multivariante , Proyectos Piloto , Reproducibilidad de los Resultados , Neoplasias de la Tiroides/patologíaRESUMEN
BACKGROUND: Numerous laboratory based studies have documented that aggressive hydration strategies (approximately 1-2 litres/h) are required to minimise a rise in core temperature and minimise the deleterious effects of hyperthermia on performance. However, field data on the relations between hydration level, core body temperature, and performance are rare. OBJECTIVE: To measure core temperature (Tcore) in triathletes during a 226 km Ironman triathlon, and to compare Tcore with markers of hydration status after the event. METHOD: Before and immediately after the 2004 Ironman Western Australia event (mean (SD) ambient temperature 23.3 (1.9) degrees C (range 19-26 degrees C) and 60 (14)% relative humidity (44-87%)) body mass, plasma concentrations of sodium ([Na+]), potassium ([K+]), and chloride ([Cl-]), and urine specific gravity were measured in 10 well trained triathletes. Tcore was measured intermittently during the event using an ingestible pill telemetry system, and heart rate was measured throughout. RESULTS: Mean (SD) performance time in the Ironman triathlon was 611 (49) minutes; heart rate was 143 (9) beats/min (83 (6)% of maximum) and Tcore was 38.1 (0.3) degrees C. Body mass significantly declined during the race by 2.3 (1.2) kg (-3.0 (1.5)%; p < 0.05), whereas urine specific gravity significantly increased (1.011 (0.005) to 1.0170 (0.008) g/ml; p < 0.05) and plasma [Na+], [K+], and [Cl-] did not change. Changes in body mass were not related to finishing Tcore (r = -0.16), plasma [Na+] (r = 0.31), or urine specific gravity (r = -0.37). CONCLUSION: In contrast with previous laboratory based studies examining the influence of hypohydration on performance, a body mass loss of up to 3% was found to be tolerated by well trained triathletes during an Ironman competition in warm conditions without any evidence of thermoregulatory failure.
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Ciclismo/fisiología , Temperatura Corporal/fisiología , Carrera/fisiología , Natación/fisiología , Adulto , Deshidratación/prevención & control , Fiebre/prevención & control , Humanos , Masculino , Resistencia Física/fisiología , Pérdida de Peso/fisiología , Australia OccidentalRESUMEN
OBJECTIVES: To investigate the effect of cadence selection during the final minutes of cycling on metabolic responses, stride pattern, and subsequent running time to fatigue. METHODS: Eight triathletes performed, in a laboratory setting, two incremental tests (running and cycling) to determine peak oxygen uptake (VO2PEAK) and the lactate threshold (LT), and three cycle-run combinations. During the cycle-run sessions, subjects completed a 30 minute cycling bout (90% of LT) at (a) the freely chosen cadence (FCC, 94 (5) rpm), (b) the FCC during the first 20 minutes and FCC-20% during the last 10 minutes (FCC-20%, 74 (3) rpm), or (c) the FCC during the first 20 minutes and FCC+20% during the last 10 minutes (FCC+20%, 109 (5) rpm). After each cycling bout, running time to fatigue (Tmax) was determined at 85% of maximal velocity. RESULTS: A significant increase in Tmax was found after FCC-20% (894 (199) seconds) compared with FCC and FCC+20% (651 (212) and 624 (214) seconds respectively). VO2, ventilation, heart rate, and blood lactate concentrations were significantly reduced after 30 minutes of cycling at FCC-20% compared with FCC+20%. A significant increase in VO2 was reported between the 3rd and 10th minute of all Tmax sessions, without any significant differences between sessions. Stride pattern and metabolic variables were not significantly different between Tmax sessions. CONCLUSIONS: The increase in Tmax after FCC-20% may be associated with the lower metabolic load during the final minutes of cycling compared with the other sessions. However, the lack of significant differences in metabolic responses and stride pattern between the run sessions suggests that other mechanisms, such as changes in muscular activity, probably contribute to the effects of cadence variation on Tmax
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Ciclismo/fisiología , Fatiga/metabolismo , Carrera/fisiología , Adulto , Metabolismo Energético/fisiología , Prueba de Esfuerzo/métodos , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Fatiga Muscular/fisiología , Consumo de Oxígeno/fisiología , Resistencia Física/fisiología , Natación/fisiología , Factores de TiempoRESUMEN
The aim of this study was to investigate the effects of the new estro-progestinic containing the antimineralcorticoid progestogen drospirenone (DRSP) in women with polycystic ovary syndrome (PCOS). Fifteen hirsute PCOS patients were treated with 30 microg ethinyl estradiol plus 3 mg DRSP for 12 cycles. Ultrasonographic pelvic exams, evaluation of hirsutism scores, and hormonal and lipid profile assays were performed at baseline and after three, six, and 12 cycles of treatment. An oral glucose tolerance test and euglycemic hyperinsulinemic clamp were also performed, except at the third cycle. The treatment was well tolerated, and all women attained satisfactory cycle control. Hirsutism significantly improved from the sixth cycle onward. Body weight and fat distribution as well as blood pressure remained stable throughout the treatment. Plasma levels of LH, testosterone, SHBG, and, consequently, the free androgen index significantly fell from the third cycle on. Dehydroepiandrosterone sulfate and 17-hydroxyprogesterone significantly decreased after six cycles. The treatment did not affect glycoinsulinemic homeostasis. A trend toward an increase was seen for total cholesterol, triglycerides, and high- and low-density lipoproteins (HDL and LDL) plasma concentrations, although all parameters remained within the normal range. No modifications in total cholesterol/HDL and HDL/LDL ratios were induced by the therapy. The ethinyl estradiol/DRSP combination seems to be effective in ameliorating clinical and hormonal features of PCOS.
Asunto(s)
Androstenos/administración & dosificación , Hirsutismo/tratamiento farmacológico , Hirsutismo/metabolismo , Antagonistas de Receptores de Mineralocorticoides/administración & dosificación , Síndrome del Ovario Poliquístico/tratamiento farmacológico , Síndrome del Ovario Poliquístico/metabolismo , Adulto , Presión Sanguínea , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Quimioterapia Combinada , Estrógenos/administración & dosificación , Etinilestradiol/administración & dosificación , Femenino , Hirsutismo/etiología , Humanos , Persona de Mediana Edad , Proyectos Piloto , Síndrome del Ovario Poliquístico/complicaciones , Resultado del Tratamiento , Triglicéridos/sangreRESUMEN
BACKGROUND: To investigate the effect of pioglitazone on adrenal steroidogenesis in polycystic ovary syndrome (PCOS), we studied 11 obese (two with BMI >25 kg/m(2); nine with BMI >27 kg/m(2)) PCOS women before and after 6 months of treatment at a dose of 45 mg/day. METHODS: During the early follicular phase, ultrasonography and hormonal assays were performed. On separate days, all women underwent an oral glucose tolerance test (OGTT), a euglycaemic hyperinsulinaemic clamp and an adrenocorticotrophin hormone (ACTH) test. The same protocol was repeated after therapy. RESULTS: Pioglitazone treatment significantly reduced the insulin response to OGTT and improved the insulin sensitivity indices (P < 0.01 and P = 0.03 respectively). A significant decrease was found in LH (P < 0.05) and androstenedione (P < 0.01) levels after therapy, whereas the other hormonal parameters improved but not significantly. Pioglitazone administration reduced the response of 17alpha-hydroxyprogesterone (17OHP) and androstenedione to ACTH (P < 0.01 and P < 0.02 respectively), most likely through an inhibition of cytochrome P450. The same treatment was able to rebalance the relative activity of 17,20-lyase, as documented by an increase in the androstenedione:17OHP ratio (P < 0.05) after ACTH stimulation. CONCLUSIONS: Our data support the contention that insulin enhances ACTH-stimulated steroidogenesis, while inducing a relative impairment of 17,20-lyase activity. Whether the beneficial effects of pioglitazone on this imbalance could be related to the ameliorated glyco-insulinaemic metabolism or to a direct effect on the adrenal glands remains to be determined.
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Glándulas Suprarrenales/metabolismo , Andrógenos/metabolismo , Hipoglucemiantes/administración & dosificación , Obesidad/complicaciones , Síndrome del Ovario Poliquístico/tratamiento farmacológico , Síndrome del Ovario Poliquístico/metabolismo , Tiazolidinedionas/administración & dosificación , 17-alfa-Hidroxiprogesterona/metabolismo , Hormona Adrenocorticotrópica , Adulto , Androstenodiona/sangre , Androstenodiona/metabolismo , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Prueba de Tolerancia a la Glucosa , Hormonas/sangre , Humanos , Insulina/sangre , Resistencia a la Insulina , Hormona Luteinizante/sangre , Pioglitazona , Síndrome del Ovario Poliquístico/complicaciones , Síndrome del Ovario Poliquístico/diagnóstico , Esteroide 17-alfa-Hidroxilasa/antagonistas & inhibidoresRESUMEN
Polycystic ovary syndrome (PCOS) is the most common endocrine disorders among women in reproductive age, but diagnostic criteria used in clinical practice are still controversial. In 1990 the National Institute of HEALTH (NIH) conference on PCOS recommended that diagnostic criteria should include biochemical evidence of hyperandrogenism and ovarian dysfunction (in the absence of non-classical adrenal hyperplasia) without considering the morphological diagnosis of polycystic ovary by ultrasound as an essential part of the diagnosis. In the Rotterdam PCOS workshop of May 2003, however, PCOS is diagnosed when 2 of the following criteria are recognized: oligomenorrhea and/or anovulation, clinical or biochemical signs of hyperandrogenism, ultrasound findings of polycystic ovary. Further-more, it is underlined that the metabolic study is not necessary for PCOS diagnosis, while it is suggested for "at risk patients" (obesity, diabetes, familiar and obstetrical history) with an oral glucose tolerance test (OGTT). A recent study carried out by our group underlined the role of ultrasound parameter, in particular suggesting a ratio between ovarian stroma area and total area of the ovarian section (S/A), with a cut-off of 0.34, as "gold parameter" for PCOS diagnosis, because it shows high sensitivity and specificity (96.3%, 97.0% for the S/A).
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Síndrome del Ovario Poliquístico/diagnóstico , Adulto , Complicaciones de la Diabetes , Diagnóstico Diferencial , Femenino , Humanos , Resistencia a la Insulina , Obesidad/complicaciones , Síndrome del Ovario Poliquístico/clasificación , Síndrome del Ovario Poliquístico/diagnóstico por imagen , Factores de Riesgo , Sensibilidad y Especificidad , Factores de Tiempo , Ultrasonografía DopplerRESUMEN
During 1989, a major environmental and health risk issue, the spraying of Alar on apples, created a furor among the American people. After hearing charges from the Natural Resources Defense Council (NRDC) that eating Alar-laden apples significantly increased a child's risk of developing cancer, numbers of school districts dropped apples from their menus and parents poured apple juice down the drains. Apple sales plummeted. The NRDC's charges, which were disseminated by a well-planned and effective public relations campaign, brought counter-charges from the US environmental Protection Agency, which accused the NRDC of basing its study on poor data, among other things. The core of the dispute was in the risk figures and risk interpretations being used by each organization.