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1.
J Physiol ; 596(2): 163-180, 2018 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-29143975

RESUMEN

KEY POINTS: Cardiac hypertrophy following endurance-training is thought to be due to hypertrophy of existing cardiomyocytes. The benefits of endurance exercise on cardiac hypertrophy are generally thought to be short-lived and regress to sedentary levels within a few weeks of stopping endurance training. We have now established that cardiomyocyte hyperplasia also plays a considerable role in cardiac growth in response to just 4 weeks of endurance exercise in juvenile (5-9 weeks of age) rats. The effect of endurance exercise on cardiomyocyte hyperplasia diminishes with age and is lost by adulthood. We have also established that the effect of juvenile exercise on heart mass is sustained into adulthood. ABSTRACT: The aim of this study was to investigate if endurance training during juvenile life 'reprogrammes' the heart and leads to sustained improvements in the structure, function, and morphology of the adult heart. Male Wistar Kyoto rats were exercise trained 5 days week-1 for 4 weeks in either juvenile (5-9 weeks of age), adolescent (11-15 weeks of age) or adult life (20-24 weeks of age). Juvenile exercise training, when compared to 24-week-old sedentary rats, led to sustained increases in left ventricle (LV) mass (+18%; P < 0.05), wall thickness (+11%; P < 0.05), the longitudinal area of binucleated cardiomyocytes (P < 0.05), cardiomyocyte number (+36%; P < 0.05), and doubled the proportion of mononucleated cardiomyocytes (P < 0.05), with a less pronounced effect of exercise during adolescent life. Adult exercise training also increased LV mass (+11%; P < 0.05), wall thickness (+6%; P < 0.05) and the longitudinal area of binucleated cardiomyocytes (P < 0.05), despite no change in cardiomyocyte number or the proportion of mono- and binucleated cardiomyocytes. Resting cardiac function, LV chamber dimensions and fibrosis levels were not altered by juvenile or adult exercise training. At 9 weeks of age, juvenile exercise significantly reduced the expression of microRNA-208b, which is a known regulator of cardiac growth, but this was not sustained to 24 weeks of age. In conclusion, juvenile exercise leads to physiological cardiac hypertrophy that is sustained into adulthood long after exercise training has ceased. Furthermore, this cardiac reprogramming is largely due to a 36% increase in cardiomyocyte number, which results in an additional 20 million cardiomyocytes in adulthood.


Asunto(s)
Cardiomegalia/fisiopatología , Reprogramación Celular , Miocitos Cardíacos/fisiología , Condicionamiento Físico Animal , Animales , Cardiomegalia/rehabilitación , Células Cultivadas , Hemodinámica , Masculino , Miocitos Cardíacos/citología , Resistencia Física , Ratas , Ratas Endogámicas WKY
2.
Psychol Med ; 48(4): 642-653, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-28745268

RESUMEN

BACKGROUND: Body image disturbance (BID) is a core symptom of anorexia nervosa (AN), but as yet distinctive features of BID are unknown. The present study aimed at disentangling perceptual and attitudinal components of BID in AN. METHODS: We investigated n = 24 women with AN and n = 24 controls. Based on a three-dimensional (3D) body scan, we created realistic virtual 3D bodies (avatars) for each participant that were varied through a range of ±20% of the participants' weights. Avatars were presented in a virtual reality mirror scenario. Using different psychophysical tasks, participants identified and adjusted their actual and their desired body weight. To test for general perceptual biases in estimating body weight, a second experiment investigated perception of weight and shape matched avatars with another identity. RESULTS: Women with AN and controls underestimated their weight, with a trend that women with AN underestimated more. The average desired body of controls had normal weight while the average desired weight of women with AN corresponded to extreme AN (DSM-5). Correlation analyses revealed that desired body weight, but not accuracy of weight estimation, was associated with eating disorder symptoms. In the second experiment, both groups estimated accurately while the most attractive body was similar to Experiment 1. CONCLUSIONS: Our results contradict the widespread assumption that patients with AN overestimate their body weight due to visual distortions. Rather, they illustrate that BID might be driven by distorted attitudes with regard to the desired body. Clinical interventions should aim at helping patients with AN to change their desired weight.


Asunto(s)
Anorexia Nerviosa/psicología , Imagen Corporal/psicología , Peso Corporal , Realidad Virtual , Adolescente , Adulto , Actitud , Biometría , Estudios de Casos y Controles , Femenino , Humanos , Percepción del Peso , Adulto Joven
3.
Clin Otolaryngol ; 42(6): 1130-1134, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28128522

RESUMEN

OBJECTIVE: The extent of initial surgical management in papillary thyroid cancer (PTC) is controversial. We examined whether the presence of perioperative antithyroglobulin antibodies (TGA) could predict long-term recurrence and occurrence of adverse features among a homogenous group of patients with PTC. METHODS: The clinical features of patients with PTC treated at a single institution (Jewish General Hospital, McGill University, Montreal, Canada) were obtained from the medical records, and all clinicopathologic information was reviewed. Only low-risk PTC without clinical evidence of nodal disease before surgery and treated with 30 mCi of radioactive iodine was included in the study. RESULTS: The chart review retrieved 361 patients with a median follow-up of 85.0 months (Q25-Q75 73-98). Forty-two (11.6%) patients had presence of perioperative TGA. Perioperative TGAs were associated with present extrathyroidal extension (P=.005), unsuspected nodal disease (P=.001) and autoimmune thyroiditis (P<.0001). Overall, 17 (4.7%) patients experienced locoregional recurrence. Perioperative TGAs were a significant predictor of recurrence in univariable (P=.021) but not in multivariable analysis (P=.13). CONCLUSION: Presence of perioperative TGAs is associated with aggressive histological features and the presence of thyroiditis. Detection of TGA perioperatively may encourage surgeons to consider more extensive initial surgery.


Asunto(s)
Autoanticuerpos/sangre , Carcinoma Papilar/sangre , Carcinoma Papilar/patología , Recurrencia Local de Neoplasia/sangre , Neoplasias de la Tiroides/sangre , Neoplasias de la Tiroides/patología , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Papilar/cirugía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/etiología , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Factores de Riesgo , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides/cirugía , Tiroidectomía , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
4.
Int J Sports Med ; 35(12): 1006-11, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24838267

RESUMEN

The aim of this study was to investigate the effects of acute vibration exercise, at 2 different frequencies, on upper body power output. Muscle activity (EMG) and upper-body peak power was measured in 12 healthy males during ballistic bench press throws at 30% of 1-repetition maximum on a Smith machine. Measures were made prior to, 30 s and 5 min after one of 3 conditions performed for 30 s in a press-up position: side-alternating vibration at 20 Hz, 26 Hz and no vibration. EMG was recorded in the anterior deltoid, triceps brachii and pectoralis major during ballistic bench press throws as well as during application of each condition. While peak power output was higher at 5 min post condition across all conditions, compared to baseline measures (P<0.05), only 20 Hz vibration resulted in a significant increase in peak power output (P<0.05) compared to no vibration. EMG was greater during both vibration conditions, compared to no vibration (P<0.001). However, this difference was not evident during bench press throws when no difference was seen in muscle activity between conditions. These findings suggest that 20 Hz vibration has an ergogenic effect on upper-body power that may be due to peripheral, rather than central, mediated mechanisms.


Asunto(s)
Fuerza Muscular/fisiología , Extremidad Superior/fisiología , Vibración , Ejercicio de Calentamiento/fisiología , Levantamiento de Peso/fisiología , Adulto , Músculo Deltoides/fisiología , Electromiografía , Humanos , Masculino , Músculo Esquelético/fisiología , Músculos Pectorales/fisiología , Adulto Joven
5.
Redox Biol ; 67: 102918, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37812879

RESUMEN

We recently developed a novel keratin-derived protein (KDP) rich in cysteine, glycine, and arginine, with the potential to alter tissue redox status and insulin sensitivity. The KDP was tested in 35 human adults with type-2 diabetes mellitus (T2DM) in a 14-wk randomised controlled pilot trial comprising three 2×20 g supplemental protein/day arms: KDP-whey (KDPWHE), whey (WHEY), non-protein isocaloric control (CON), with standardised exercise. Outcomes were measured morning fasted and following insulin-stimulation (80 mU/m2/min hyperinsulinaemic-isoglycaemic clamp). With KDPWHE supplementation there was good and very-good evidence for moderate-sized increases in insulin-stimulated glucose clearance rate (GCR; 26%; 90% confidence limits, CL 2%, 49%) and skeletal-muscle microvascular blood flow (46%; 16%, 83%), respectively, and good evidence for increased insulin-stimulated sarcoplasmic GLUT4 translocation (18%; 0%, 39%) vs CON. In contrast, WHEY did not effect GCR (-2%; -25%, 21%) and attenuated HbA1c lowering (14%; 5%, 24%) vs CON. KDPWHE effects on basal glutathione in erythrocytes and skeletal muscle were unclear, but in muscle there was very-good evidence for large increases in oxidised peroxiredoxin isoform 2 (oxiPRX2) (19%; 2.2%, 35%) and good evidence for lower GPx1 concentrations (-40%; -4.3%, -63%) vs CON; insulin stimulation, however, attenuated the basal oxiPRX2 response (4%; -16%, 24%), and increased GPx1 (39%; -5%, 101%) and SOD1 (26%; -3%, 60%) protein expression. Effects of KDPWHE on oxiPRX3 and NRF2 content, phosphorylation of capillary eNOS and insulin-signalling proteins upstream of GLUT4 translocation AktSer437 and AS160Thr642 were inconclusive, but there was good evidence for increased IRSSer312 (41%; 3%, 95%), insulin-stimulated NFκB-DNA binding (46%; 3.4%, 105%), and basal PAK-1Thr423/2Thr402 phosphorylation (143%; 66%, 257%) vs WHEY. Our findings provide good evidence to suggest that dietary supplementation with a novel edible keratin protein in humans with T2DM may increase glucose clearance and modify skeletal-muscle tissue redox and insulin sensitivity within systems involving peroxiredoxins, antioxidant expression, and glucose uptake.


Asunto(s)
Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Adulto , Humanos , Glucosa/metabolismo , Cisteína/metabolismo , Proyectos Piloto , Insulina/metabolismo , Músculo Esquelético/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Isoformas de Proteínas/metabolismo , Suplementos Dietéticos , Oxidación-Reducción , Queratinas/metabolismo , Queratinas/farmacología
6.
Diabetologia ; 53(4): 779-85, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20225398

RESUMEN

AIMS/HYPOTHESIS: We measured components of the kallikrein- kinin system in human type 2 diabetes mellitus and the effects of statin therapy on the circulating kallikrein-kinin system. METHODS: Circulating levels of bradykinin and kallidin peptides, and high and low molecular weight kininogens, as well as plasma and tissue kallikrein, and kallistatin were measured in non-diabetic and diabetic patients before coronary artery bypass graft surgery. Tissue kallikrein levels in atrial tissue were examined by immunohistochemistry and atrial tissue kallikrein mRNA quantified. RESULTS: Plasma levels of tissue kallikrein were approximately 62% higher in diabetic than in non-diabetic patients (p=0.001), whereas no differences were seen in circulating levels of bradykinin and kallidin peptides, and high and low molecular weight kininogens, or in plasma kallikrein or kallistatin. Immunohistochemistry revealed a twofold increase in tissue kallikrein levels in atrial myocytes (p= 0.015), while tissue kallikrein mRNA levels were increased eightfold in atrial tissue of diabetic patients (p=0.014). Statin therapy did not change any variables of the circulating kallikrein-kinin system. Neither aspirin, calcium antagonists, beta blockers or long-acting nitrate therapies influenced any kallikrein-kinin system variable. CONCLUSIONS/INTERPRETATION: Tissue kallikrein levels are increased in type 2 diabetes, whereas statin therapy does not modify the circulating kallikrein-kinin system. Cardiac tissue kallikrein may play a greater cardioprotective role in type 2 diabetic than in non-diabetic patients and contribute to the benefits of ACE inhibitor therapy in type 2 diabetic patients. However, our findings do not support a role for the kallikrein-kinin system in mediating the effects of statin therapy on endothelial function.


Asunto(s)
Diabetes Mellitus Tipo 2/enzimología , Calicreínas de Tejido/sangre , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Cardiotónicos/sangre , Puente de Arteria Coronaria , Diabetes Mellitus Tipo 2/sangre , Angiopatías Diabéticas/sangre , Angiopatías Diabéticas/tratamiento farmacológico , Angiopatías Diabéticas/cirugía , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/fisiopatología , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Inmunohistoquímica , ARN Mensajero/genética , Calicreínas de Tejido/genética
7.
Clin Infect Dis ; 50(5): 672-8, 2010 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-20121412

RESUMEN

BACKGROUND: . Severe pandemic 2009 influenza A virus (H1N1) infection is associated with risk factors that include pregnancy, obesity, and immunosuppression. After identification of immunoglobulin G(2) (IgG(2)) deficiency in 1 severe case, we assessed IgG subclass levels in a cohort of patients with H1N1 infection. METHODS: Patient features, including levels of serum IgG and IgG subclasses, were assessed in patients with acute severe H1N1 infection (defined as infection requiring respiratory support in an intensive care unit), patients with moderate H1N1 infection (defined as inpatients not hospitalized in an intensive care unit), and a random sample of healthy pregnant women. RESULTS: Among the 39 patients with H1N1 infection (19 with severe infection, 7 of whom were pregnant; 20 with moderate infection, 2 of whom were pregnant), hypoabuminemia (P < .001), anemia (P < .001), and low levels of total IgG (P= .01), IgG(1) (P= .022), and IgG(2) (15 of 19 vs 5 of 20; P= .001; mean value +/- standard deviation [SD], 1.8 +/- 1.7 g/L vs 3.4 +/- 1.4 g/L; P= .003) were all statistically significantly associated with severe H1N1 infection, but only hypoalbuminemia (P= .02) and low mean IgG(2) levels (P= .043) remained significant after multivariate analysis. Follow-up of 15 (79%) surviving IgG(2)-deficient patients at a mean (+/- SD) of 90 +/- 23 days (R, 38-126) after the initial acute specimen was obtained found that hypoalbuminemia had resolved in most cases, but 11 (73%) of 15 patients remained IgG(2) deficient. Among 17 healthy pregnant control subjects, mildly low IgG(1) and/or IgG(2) levels were noted in 10, but pregnant patients with H1N1 infection had significantly lower levels of IgG(2) (P= .001). CONCLUSIONS: Severe H1N1 infection is associated with IgG(2) deficiency, which appears to persist in a majority of patients. Pregnancy-related reductions in IgG(2) level may explain the increased severity of H1N1 infection in some but not all pregnant patients. The role of IgG(2) deficiency in the pathogenesis of H1N1 infection requires further investigation, because it may have therapeutic implications.


Asunto(s)
Deficiencia de IgG/epidemiología , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/epidemiología , Gripe Humana/virología , Adolescente , Adulto , Anciano , Femenino , Humanos , Gripe Humana/patología , Masculino , Persona de Mediana Edad , Embarazo , Adulto Joven
8.
Adv Anat Embryol Cell Biol ; 196: 1-78, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18637522

RESUMEN

There are many reasons why it is timely to review the development of the mammalian kidney. Perhaps the most important of these is the increasing amount of evidence to demonstrate that factors which impinge on/alter the normal developmental processes of this organ can have lifelong consequences for the health of the adult. The'Developmental Origins of Health and Adult Disease' (DOHaD) hypothesis, proposes that changes in the environment during the development of an organ or system, can have permanent deleterious effects leading to increased risk of cardiovascular and/or metabolic disease. The permanent metanephric kidney has been shown to be very vulnerable to such influences with many factors shown to alter both the permanent structure and the level of expression of important functional genes. Thus it is important to understand the precise timing of kidney development in terms of both structure and the genes involved at each stage. Such knowledge has been gained by significant advances in technology, which allow quantification of the number of nephrons by unbiased stereology, detections of both levels and site of gene expression,'knock-out' and knock-in' of genes in animal (mainly mouse) models and by the ability to examine nephron development, in real time, in culture systems.


Asunto(s)
Enfermedades Renales/etiología , Riñón/embriología , Animales , Investigación Biomédica/métodos , Desarrollo Embrionario/genética , Humanos , Riñón/anomalías , Riñón/fisiología
9.
Neurotox Res ; 11(2): 85-91, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17449451

RESUMEN

Exposure to OP compounds that inhibit neurotoxic esterase (NTE) induces a delayed neuropathy (OPIDN) characterized by Wallerian-like degeneration of long axons in certain animals, including humans. Pope et al. (Toxicol. Lett. 75:111-117, 1995) found that neurite outgrowth occurred following the addition of spinal cord extracts from chickens with active OPIDN to neuroblastoma cells, suggesting growth factor expression during the neuropathy. We hypothesized that, shortly after exposure to a neuropathic OP compound, the central nervous system (CNS) attempts to recover from the toxic insult through upregulation of the neurotrophins nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) in susceptible regions of the nervous system. We hypothesized that such upregulation is transient and cannot be sustained. To test this hypothesis, we exposed 10-week-old chickens to a neuropathic OP compound (PSP, 2.5 mg/kg), a non-neuropathic OP compound (paraoxon, 0.10 mg/kg), and vehicle (DMSO, 0.5 ml/kg) intramuscularly. By day 8, all PSP-treated birds demonstrated clinical signs of OPIDN. We sacrificed chickens by pentobarbital overdose at 4, 8, 24, and 48 hours, and 5 and 10 days post-exposure and confirmed NTE inhibition in birds treated with PSP 4 and 24 hours earlier. Enzyme-linked immunosorbant assays indicated that NGF, BDNF, and NT-3 are found in chicken lumbar spinal cord after exposure to a neuropathic OP compound. However, exposure to the neuropathic OP compound, PSP, did not preferentially elevate levels of NGF, BDNF, and NTE compared to the non-neuropathic OP compound, paraoxon. This suggests that these neurotrophins alone do not contribute to a sustained regenerative effort in the CNS.


Asunto(s)
Factores de Crecimiento Nervioso/metabolismo , Enfermedades del Sistema Nervioso/inducido químicamente , Enfermedades del Sistema Nervioso/metabolismo , Compuestos Organofosforados/toxicidad , Degeneración Walleriana/inducido químicamente , Degeneración Walleriana/metabolismo , Animales , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Pollos , Inhibidores de la Colinesterasa/toxicidad , Factor de Crecimiento Nervioso/metabolismo , Regeneración Nerviosa , Neurotrofina 3/metabolismo , Paraoxon/toxicidad
10.
J Dev Orig Health Dis ; 8(5): 618-625, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28975880

RESUMEN

Low birth weight is associated with increased risk of cardiovascular disease in adulthood. Intrauterine growth restriction (IUGR) hearts have fewer CMs in early postnatal life, which may impair postnatal cardiovascular function and hence, explain increased disease risk, but whether the cardiomyocyte deficit persists to adult life is unknown. We therefore studied the effects of experimentally induced placental restriction (PR) on cardiac outcomes in young adult sheep. Heart size, cardiomyocyte number, nuclearity and size were measured in control (n=5) and PR (n=5) male sheep at 1 year of age. PR lambs were 36% lighter at birth (P=0.007), had 38% faster neonatal relative growth rates (P=0.001) and had 21% lighter heart weights relative to body weight as adults (P=0.024) than control lambs. Cardiomyocyte number, nuclearity and size in the left ventricle did not differ between control and PR adults; hearts of both groups contained cardiomyocytes (CM) with between one and four nuclei. Overall, cardiomyocyte number in the adult left ventricle correlated positively with birth weight but not with adult weight. This study is the first to demonstrate that intrauterine growth directly influences the complement of CM in the adult heart. Cardiomyocyte size was not correlated with cardiomyocyte number or birth weight. Our results suggest that body weight at birth affects lifelong cardiac functional reserve. We hypothesise that decreased cardiomyocyte number of low birth weight individuals may impair their capacity to adapt to additional challenges such as obesity and ageing.


Asunto(s)
Peso al Nacer/fisiología , Miocardio/patología , Miocitos Cardíacos/patología , Factores de Edad , Animales , Recuento de Células/métodos , Tamaño de la Célula , Femenino , Predicción , Humanos , Masculino , Embarazo , Ovinos
11.
J Endocrinol ; 232(2): 175-187, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27821470

RESUMEN

Preterm birth is associated with increased risk of type 2 diabetes (T2D) in adulthood; however, the underlying mechanisms are poorly understood. We therefore investigated the effect of preterm birth at ~0.9 of term after antenatal maternal betamethasone on insulin sensitivity, secretion and key determinants in adulthood, in a clinically relevant animal model. Glucose tolerance and insulin secretion (intravenous glucose tolerance test) and whole-body insulin sensitivity (hyperinsulinaemic euglycaemic clamp) were measured and tissue collected in young adult sheep (14 months old) after epostane-induced preterm (9M, 7F) or term delivery (11M, 6F). Glucose tolerance and disposition, insulin secretion, ß-cell mass and insulin sensitivity did not differ between term and preterm sheep. Hepatic PRKAG2 expression was greater in preterm than in term males (P = 0.028), but did not differ between preterm and term females. In skeletal muscle, SLC2A4 (P = 0.019), PRKAA2 (P = 0.021) and PRKAG2 (P = 0.049) expression was greater in preterm than in term overall and in males, while INSR (P = 0.047) and AKT2 (P = 0.043) expression was greater in preterm than in term males only. Hepatic PRKAG2 expression correlated positively with whole-body insulin sensitivity in males only. Thus, preterm birth at 0.9 of term after betamethasone does not impair insulin sensitivity or secretion in adult sheep, and has sex-specific effects on gene expression of the insulin signalling pathway. Hence, the increased risk of T2D in preterm humans may be due to factors that initiate preterm delivery or in early neonatal exposures, rather than preterm birth per se.


Asunto(s)
Betametasona/farmacología , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Resistencia a la Insulina/fisiología , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Nacimiento Prematuro , Efectos Tardíos de la Exposición Prenatal/metabolismo , Animales , Modelos Animales de Enfermedad , Femenino , Técnica de Clampeo de la Glucosa , Células Secretoras de Insulina/efectos de los fármacos , Masculino , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Embarazo , Factores Sexuales , Ovinos , Oveja Doméstica , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología
12.
J Natl Cancer Inst ; 93(10): 745-53, 2001 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-11353784

RESUMEN

BACKGROUND: 1alpha,25-Dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] and its analogues inhibit growth of various types of cancer cells. Although the therapeutic potential of 1,25(OH)(2)D(3) is limited by its tendency to induce hypercalcemia, analogues such as EB1089 are potent inhibitors of cell growth and exhibit reduced calcemic effects. We analyzed the antiproliferative and calcemic effects of EB1089 in tissue culture and animal models of head and neck squamous cell carcinoma (SCC) to investigate its potential as a chemotherapeutic/chemopreventive agent. METHODS: The effects of 1,25(OH)(2)D(3) and EB1089 on cell growth and expression of p21(WAF1/CIP1) and p27(KIP1), which encode cyclin-dependent kinase inhibitors, and a novel target, gadd45alpha, a growth-arrest and DNA-damage gene, were monitored in cultured murine AT-84 SCC cells. The effects of these agents on AT-84 cell growth in vitro and on growth of AT-84 tumors in syngeneic C3H mice were monitored; treatment started at the time of tumor implantation (early tumor model) or after 12 days (late tumor model). Weight and serum calcium levels were also monitored in these animals. All P values were two-sided. RESULTS: Both 1,25(OH)(2)D(3) and EB1089 arrested proliferation of AT-84 cells in G(0)/G(1) phase, inhibited p21(WAF1/CIP1) expression, and induced expression of p27(KIP1) protein. 1,25(OH)(2)D(3) also enhanced the expression of gadd45alpha, apparently by a p53-independent mechanism. There was a statistically significant decrease in tumor growth for 1,25(OH)(2)D(3)-treated mice (P<.001 for early tumor model) and EB1089-treated mice (P<.001 and P =.001 for early and late tumor models, respectively). Unlike 1,25(OH)(2)D(3), EB1089 did not induce cachexia or hypercalcemia. The effects of 1,25(OH)(2)D(3) and EB1089 on expression of p21(WAF1/CIP1) and GADD45alpha were similar in tumors and in vitro. CONCLUSIONS: EB1089 completely inhibited growth of AT-84 SCC cells at nanomolar concentrations, reduced tumor growth, and did not have calcemic effects. Our results support continued investigation of EB1089 as a chemopreventive/chemotherapeutic agent for head and neck SCC.


Asunto(s)
Antineoplásicos/uso terapéutico , Calcitriol/análogos & derivados , Calcitriol/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Proteínas de Ciclo Celular , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Proteínas Supresoras de Tumor , Animales , Northern Blotting , Western Blotting , Carcinoma de Células Escamosas/prevención & control , Ciclo Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Inhibidor p27 de las Quinasas Dependientes de la Ciclina , Ciclinas/biosíntesis , Citoplasma/metabolismo , Daño del ADN/genética , Genes p53/genética , Neoplasias de Cabeza y Cuello/prevención & control , Inmunohistoquímica , Péptidos y Proteínas de Señalización Intracelular , Masculino , Ratones , Ratones Endogámicos C3H , Proteínas Asociadas a Microtúbulos/biosíntesis , Trasplante de Neoplasias , Pruebas de Precipitina , Proteínas/metabolismo , ARN/metabolismo , Factores de Tiempo , Células Tumorales Cultivadas , Proteinas GADD45
13.
Cancer Res ; 44(10): 4366-76, 1984 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-6088037

RESUMEN

Carbamyl phosphate (CAP) is a key compound of the biosynthetic pathways for pyrimidines and urea. CAP can also be catabolyzed by phosphatases which hydrolyze CAP to carbamate and orthophosphate. This CAP phosphatase activity was studied from tissue preparations of Ehrlich ascites carcinoma cells, SV-40-transformed Syrian hamster cells, and normal tissues of the rat. A procedure for subcellular fractionation of Ehrlich ascites carcinoma cells was developed, so that cellular contents might be divided into nuclear, mitochondrial, lysosomal, microsomal, and cytosolic fractions. Plasma membranes were found primarily in the lysosomal fraction. There were at least 3 different CAP-hydrolyzing phosphatases, each occurring predominantly in different fractions, namely, the lysosomal, cytosolic, and microsomal fractions. These fractions contained 51, 20, and 14% of homogenate CAP phosphatase activity, respectively. The pH maximum for each of these phosphatases was 8, 5.7, and 7.5, respectively, and all fractions were stimulated by Mg2+. It was determined that activity in the lysosomal fraction resided with the plasma membrane fragments. The CAP phosphatase activities associated with the plasma membrane and cytosol were further studied. The Km for CAP of both fractions was 1.1 mM. The lysosomal fraction specific activity for CAP hydrolysis was 602 nmol/min/mg at pH 7.4 and 37 degrees and was 8-fold greater than was the specific activity of the cytosolic fraction. The two fractions differed in response to Mg2+, K+, and other ions and inhibitors. A crude subcellular fractionation of rat liver was also performed, and 92% of the activity was found in the particulate fractions. Levels of CAP phosphatase activity in homogenates of normal rat tissues varied: whole blood less than muscle less than liver less than kidney less than brain. Ehrlich ascites carcinoma cell and muscle homogenate activities were comparable at 72 and 73 nmol/min/mg at pH 7.4 and 24 degrees. CAP phosphatase activity was measured in homogenates of SV40-transformed Syrian hamster mutant cell lines with various levels of aspartate transcarbamylase and variable sensitivity to the aspartate transcarbamylase competitive inhibitor, N-(phosphonacetyl)-L-aspartate.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Ácido Anhídrido Hidrolasas , Carcinoma de Ehrlich/enzimología , Riñón/enzimología , Hígado/enzimología , Monoéster Fosfórico Hidrolasas/metabolismo , Animales , Cationes , Fraccionamiento Celular , Línea Celular , Cricetinae , Concentración de Iones de Hidrógeno , Isoenzimas/aislamiento & purificación , Isoenzimas/metabolismo , Cinética , Masculino , Mesocricetus , Ratones , Mutación , Monoéster Fosfórico Hidrolasas/aislamiento & purificación , Ratas , Ratas Endogámicas , Fracciones Subcelulares/enzimología , Distribución Tisular , Acilfosfatasa
14.
J Laryngol Otol ; 130(4): 393-7, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26875509

RESUMEN

BACKGROUND: Merkel cell carcinoma is a rare, aggressive neurocutaneous malignancy. This study investigated whether patients with Merkel cell carcinoma in the head and neck had poorer outcomes than patients with Merkel cell carcinoma located elsewhere. METHODS: A retrospective study was performed of patients with Merkel cell carcinoma treated at the Jewish General Hospital in Montréal, Canada, from 1993 to 2013. Associations between clinicopathological characteristics and disease-free and disease-specific survival rates were examined according to the Kaplan-Meier method. RESULTS: Twenty-seven patients were identified. Although basic clinicopathological characteristics and treatments were similar between head and neck and non-head and neck Merkel cell carcinoma groups, disease-free and disease-specific survival rates were significantly lower in the head and neck Merkel cell carcinoma group (log-rank test; p = 0.043 and p = 0.001, respectively). Mortality was mainly due to distant metastasis. CONCLUSION: Patients with head and neck Merkel cell carcinoma had poorer survival rates than patients with non-head and neck Merkel cell carcinoma in our study. The tendency to obtain close margins, a less predictable metastatic pattern, and/or intrinsic tumour factors related to the head and neck may explain this discrepancy.


Asunto(s)
Carcinoma de Células de Merkel/mortalidad , Neoplasias de Cabeza y Cuello/mortalidad , Neoplasias Cutáneas/mortalidad , Anciano , Canadá , Carcinoma de Células de Merkel/patología , Supervivencia sin Enfermedad , Femenino , Neoplasias de Cabeza y Cuello/patología , Humanos , Estimación de Kaplan-Meier , Masculino , Estudios Retrospectivos , Neoplasias Cutáneas/patología , Tasa de Supervivencia
15.
J Laryngol Otol ; 130(8): 755-62, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27339712

RESUMEN

OBJECTIVES: Salivary gland transfer surgery can reduce xerostomia in oropharyngeal squamous cell carcinoma patients undergoing primary chemoradiation. A potential drawback of salivary gland transfer is the treatment delay associated with the surgery, and its complications. This study aimed to determine whether the treatment delay affects patient survival and to evaluate patient quality of life after salivary gland transfer. METHODS: A retrospective analysis of 138 patients (salivary gland transfer group, n = 58; non-salivary gland transfer group, n = 80) was performed. Patient survival was compared between these groups using multivariate analysis. Salivary gland transfer patients were further evaluated for surgical complications and for quality of life using the head and neck module of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire. RESULTS: Salivary gland transfer and non-salivary gland transfer patients had comparable baseline clinical characteristics. Salivary gland transfer patients experienced a median treatment delay of 16.5 days before chemoradiation (p = 0.035). Multivariate analysis showed that this did not, however, correspond to a survival disadvantage (p = 0.24 and p = 0.97 for disease-free and disease-specific survival, respectively). A very low complication rate was reported for the salivary gland transfer group (1.7 per cent). Questionnaire scores for the item 'xerostomia' were very low in salivary gland transfer patients. CONCLUSION: The treatment delay associated with salivary gland transfer surgery does not negatively affect patient survival. Oropharyngeal squamous cell patients have an excellent quality of life after salivary gland transfer.


Asunto(s)
Carcinoma de Células Escamosas/terapia , Neoplasias Orofaríngeas/terapia , Calidad de Vida , Glándulas Salivales/trasplante , Xerostomía/prevención & control , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Quimioradioterapia/efectos adversos , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Encuestas y Cuestionarios , Factores de Tiempo , Resultado del Tratamiento , Xerostomía/etiología
16.
Mol Endocrinol ; 15(7): 1127-39, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11435613

RESUMEN

Analogs of 1alpha,25-dihydroxyvitamin D(3) (1alpha, 25(OH)2D3) inhibit growth in vitro and in vivo of cells derived from a variety of tumors. Here, we examined the effects of 1alpha,25(OH)2D3 and its analog EB1089 on proliferation and target gene regulation of human head and neck squamous cell carcinoma (SCC) lines SCC4, SCC9, SCC15, and SCC25. A range of sensitivities to 1alpha,25(OH)2D3 and EB1089 was observed, from complete G0/G1 arrest of SCC25 cells to only 50% inhibition of SCC9 cell growth. All lines expressed similar levels of vitamin D3 receptor (VDR) mRNA and protein, and no significant variation was observed in 1alpha,25(OH)2D3-dependent induction of the endogenous 24-hydroxylase gene, or of a transiently transfected 1alpha,25(OH)2D3-sensitive reporter gene. The antiproliferative effects of 1alpha,25(OH)2D3 and EB1089 in SCC25 cells were analyzed by screening more than 4,500 genes on two cDNA microarrays, yielding 38 up-regulated targets, including adhesion molecules, growth factors, kinases, and transcription factors. Genes encoding factors implicated in cell cycle regulation were induced, including the growth arrest and DNA damage gene, gadd45alpha, and the serum- and glucocorticoid-inducible kinase gene, sgk. Induction of GADD45alpha protein in EB1089-treated cells was confirmed by Western blotting. Moreover, while expression of proliferating cell nuclear antigen (PCNA) was reduced in EB1089-treated cells, coimmunoprecipitation studies revealed increased association between GADD45alpha and PCNA in treated cells, consistent with the capacity of GADD45alpha to stimulate DNA repair. While 1alpha,25(OH)2D3 and EB1089 modestly induced transcripts encoding the cyclin-dependent kinase inhibitor p21(waf1/cip1), no changes in protein levels were observed, indicating that p21(waf1/cip1) induction does not contribute to the antiproliferative effects of 1alpha,25(OH)2D3 and EB1089 in SCC cells. Finally, in partially resistant SCC9 cells, there was extensive loss of target gene regulation (10 of 10 genes tested), indicating that resistance arises from widespread loss of 1alpha,25(OH)2D3-dependent gene regulation in the presence of normal levels of functional VDRs.


Asunto(s)
Calcitriol/farmacología , Carcinoma de Células Escamosas/patología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias de Cabeza y Cuello/patología , Proteínas Supresoras de Tumor , Northern Blotting , Calcitriol/análogos & derivados , Carcinoma de Células Escamosas/genética , Proteínas de Ciclo Celular/genética , División Celular/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Inhibidor p27 de las Quinasas Dependientes de la Ciclina , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Ciclinas/genética , Resistencia a Medicamentos , Neoplasias de Cabeza y Cuello/genética , Humanos , Péptidos y Proteínas de Señalización Intracelular , Análisis de Secuencia por Matrices de Oligonucleótidos , Antígeno Nuclear de Célula en Proliferación/metabolismo , Proteínas/genética , Proteínas/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transfección , Células Tumorales Cultivadas , Proteinas GADD45
17.
Int J Radiat Oncol Biol Phys ; 37(3): 587-91, 1997 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-9112457

RESUMEN

PURPOSE: Different radiotherapy fractionation schedules were used over a 10-year period to treat patients with early squamous cell carcinoma of the vocal cords at McGill University. A retrospective analysis was performed to study the effect of fraction size on local control in this group of patients. METHODS AND MATERIALS: A total of 126 previously untreated patients with T1 invasive squamous cell carcinoma of the true vocal cords were irradiated between January 1978 and December 1988 in the Department of Radiation Oncology at McGill University. All patients received megavoltage irradiation, 94 patients received daily fractions > 2 Gy (64 patients received 50 Gy with once-daily 2.5-Gy fractions, and 30 received 65.25 Gy in 29 fractions of 2.25 Gy each), and 32 patients were treated to a dose of 66 Gy in 33 fractions with 2 Gy/fraction. Patients' characteristics of prognostic importance were equally distributed between the two fractionation groups. RESULTS: At a median follow-up of 84 months, the 10-year disease-free survival and overall survival were 76% and 93%, respectively. Local control for patients treated with > 2 Gy fraction was 84%, compared to 65.6% for those treated with 2-Gy fractions (p = 0.026). Among the prognostic factors tested, such as gender, age, stage, anterior and posterior commissure involvement, smoking history, and fraction size, the latter was the only significant predictor of local control for the whole group of patients in univariate (p = 0.041) and multivariate (p = 0.023) analysis. There was no observed difference in the incidence of complications between the two fractionation groups. CONCLUSIONS: From the results of this retrospective review of patients treated with radiotherapy for T1 true vocal cord cancer, and within the range of total doses and overall treatment times used in our patients, it was found that fractionation schedules using daily fraction size > 2 Gy are associated with a better local control than schedules delivering 2 Gy/fraction, with no increase in toxicity.


Asunto(s)
Carcinoma de Células Escamosas/radioterapia , Neoplasias Laríngeas/radioterapia , Pliegues Vocales , Carcinoma de Células Escamosas/patología , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Laríngeas/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Dosificación Radioterapéutica , Estudios Retrospectivos , Factores Sexuales , Insuficiencia del Tratamiento , Pliegues Vocales/patología
18.
J Hypertens ; 15(9): 945-54, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9321741

RESUMEN

OBJECTIVE: To examine the role played by angiotensin II (AII) in the development of prehypertensive vascular hypertrophy in the spontaneously hypertensive rat (SHR) and to determine whether normalization of prehypertensive vascular hypertrophy attenuates the development of hypertension. DESIGN: Male SHR and Wistar-Kyoto (WKY) rats were treated from age 10 days until age 6 weeks with perindopril, an angiotensin converting enzyme (ACE) inhibitor, or with losartan, a type 1 AII receptor antagonist. METHODS: At termination of treatment, or 8 weeks after cessation of treatment, vascular growth was assessed by measurement of hindquarter resistance properties and of the medial cross-sectional area of first-order mesenteric arteries. The growth of the heart was assessed by measurement of the left ventricle:body weight ratio. RESULTS: Perindopril and losartan treatment of SHR and WKY rats led to a heterogeneous response in the vasculature, resulting in a reduction in perfusion pressures at maximum dilatation and constriction in the hindquarter vasculature but no significant change in medial cross-sectional area of small mesenteric arteries. Neither perindopril nor losartan treatment affected the growth of the left ventricle in the SHR. After the cessation of treatment the development of hypertension in the losartan- and perindopril-treated SHR did not differ from that in controls. CONCLUSION: These results suggest that AII, acting via angiotensin type 1 receptors, plays an important role in determining the early post-natal reactivity of the hindquarter vasculature but not the medial cross-sectional area of the mesenteric vasculature, which implies that different growth regulatory mechanisms are operating in the two vascular beds. The lack of effect in some vascular beds, together with the lack of effect on the heart, may account for the absence of a persistent effect on the blood pressure.


Asunto(s)
Angiotensina II/fisiología , Sistema Cardiovascular/patología , Hipertensión/etiología , Hipertrofia/prevención & control , Resistencia Vascular/efectos de los fármacos , Angiotensina II/antagonistas & inhibidores , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Animales , Animales Recién Nacidos , Antihipertensivos/farmacología , Antihipertensivos/uso terapéutico , Peso Corporal/efectos de los fármacos , Cardiomegalia/prevención & control , Sistema Cardiovascular/efectos de los fármacos , Hipertensión/patología , Hipertensión/prevención & control , Indoles/farmacología , Indoles/uso terapéutico , Riñón/patología , Losartán/farmacología , Losartán/uso terapéutico , Masculino , Arterias Mesentéricas/anatomía & histología , Arterias Mesentéricas/efectos de los fármacos , Tamaño de los Órganos/efectos de los fármacos , Papaverina/farmacología , Perindopril , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Factores de Tiempo
19.
J Hypertens ; 19(4): 785-94, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11330882

RESUMEN

OBJECTIVE: To determine whether angiotensin-converting enzyme (ACE) inhibition treatment enhances myocardial vascularization in adolescent and adult spontaneously hypertensive rats (SHRs). METHODS: Male SHRs were treated from 7 to 14 or from 16 to 24 weeks of age with the ACE inhibitor, perindopril, in either a low dose (0.1 mg/kg per day) or a high dose (1 mg/kg per day). Some rats were concomitantly treated with a bradykinin antagonist. At termination of treatment, the left ventricular wall was extensively sampled and the surface area density and length density of myocardial blood vessels stereologically determined. RESULTS: High-dose perindopril treatment prevented the development of hypertension and left ventricular hypertrophy in adolescent SHRs and markedly reduced blood pressure and left ventricular size in adult SHRs. SHRs treated with the low dose of perindopril remained hypertensive, although there were significant reductions in blood pressure and left ventricular growth. High-dose perindopril treatment in adolescent SHRs led to a significant increase in the surface area density of blood vessels in the left ventricle after 4 weeks of treatment and an increase in both the surface area density and length density of blood vessels after 7 weeks of treatment Co-administration with the bradykinin antagonist did not reverse these effects. In contrast, ACE inhibitor treatment had no effect on myocardial vascularization in adult rats with established hypertension. CONCLUSION: ACE inhibitor treatment enhances vascularization in the adolescent heart through reductions in myocardial mass, but not capillary growth. ACE inhibition in the adult heart with established hypertension reduces left ventricular hypertrophy, but does not enhance myocardial capillarization.


Asunto(s)
Envejecimiento/fisiología , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Circulación Coronaria/efectos de los fármacos , Hipertensión/fisiopatología , Perindopril/farmacología , Ratas Endogámicas SHR/fisiología , Animales , Presión Sanguínea/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Capilares/efectos de los fármacos , Capilares/crecimiento & desarrollo , Relación Dosis-Respuesta a Droga , Corazón/crecimiento & desarrollo , Hipertensión/patología , Hipertensión/prevención & control , Hipertrofia Ventricular Izquierda/prevención & control , Ratas , Ratas Endogámicas SHR/anatomía & histología , Ratas Endogámicas WKY , Valores de Referencia , Sístole , Función Ventricular Izquierda/efectos de los fármacos
20.
J Hypertens ; 12(10): 1163-70, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7836732

RESUMEN

OBJECTIVE: To investigate the role of angiotensin II (Ang II) in cardiovascular hypertrophy in the Goldblatt one-kidney, one clip (1-K, 1C) renal hypertensive rat. METHODS: Six-week-old Wistar-Kyoto (WKY) rats underwent uninephrectomy and left renal artery clipping. After surgery, rats were treated with perindopril, an angiotensin converting enzyme (ACE) inhibitor, or losartan, an Ang II type 1 (AT1) receptor antagonist, for 4 weeks. Untreated 1-K, 1C rats and uninephrectomized (sham) rats served as controls. RESULTS: The rise in systolic blood pressure in the perindopril-treated and losartan-treated rats was not significantly different from that in the untreated 1-K, 1C group throughout the treatment period. At 4 weeks after surgery the heart weight:body weight ratios of the untreated 1-K, 1C and losartan-treated 1-K, 1C groups were significantly greater than for sham-operated normotensive rats and hypertensive perindopril-treated rats. The total number of smooth muscle cells in the thoracic aortae of the 1-K, 1C untreated, losartan-treated 1-K, 1C and sham groups were similar. However, after treatment the aortae of the perindopril-treated group contained significantly fewer smooth muscle cells. The medial cross-sectional wall area and wall: lumen ratio were similar in the 1-K, 1C untreated and perindopril-treated 1-K, 1C groups. CONCLUSION: These results suggest that Ang II, via its effects on cardiac and vascular AT1 receptors, does not contribute to the development of cardiovascular hypertrophy in the 1-K, 1C rat. Attenuation of cardiac and vascular growth after ACE inhibition appears to be mediated by mechanisms independent of the actions of the renin-angiotensin system.


Asunto(s)
Angiotensina II/fisiología , Aorta Torácica/patología , Cardiomegalia/patología , Hipertensión Renovascular/patología , Músculo Liso Vascular/patología , Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Compuestos de Bifenilo/farmacología , Presión Sanguínea , Peso Corporal , Hipertensión Renovascular/fisiopatología , Hipertrofia , Imidazoles/farmacología , Indoles/farmacología , Losartán , Masculino , Perindopril , Ratas , Ratas Endogámicas WKY , Tetrazoles/farmacología
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