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1.
BJOG ; 125(11): 1397-1404, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29473290

RESUMEN

OBJECTIVE: Accurate assessment of gestational age (GA) is critical to paediatric care, but is limited in developing countries without access to ultrasound. Our objectives were to assess the accuracy of prediction of GA at birth and preterm birth classification using routinely collected anthropometry measures. DESIGN: Prospective cohort study. SETTING: United States. POPULATION OR SAMPLE: A total of 2334 non-obese and 468 obese pregnant women. METHODS: Enrolment GA was determined based on last menstrual period, confirmed by first-trimester ultrasound. Maternal anthropometry and fundal height (FH) were measured by a standardised protocol at study visits; FH alone was additionally abstracted from medical charts. Neonatal anthropometry measurements were obtained at birth. To estimate GA at delivery, we developed three predictor models using longitudinal FH alone and with maternal and neonatal anthropometry. For all predictors, we repeatedly sampled observations to construct training (60%) and test (40%) sets. Linear mixed models incorporated longitudinal maternal anthropometry and a shared parameter model incorporated neonatal anthropometry. We assessed models' accuracy under varied scenarios. MAIN OUTCOME MEASURES: Estimated GA at delivery. RESULTS: Prediction error for various combinations of anthropometric measures ranged between 13.9 and 14.9 days. Longitudinal FH alone predicted GA within 14.9 days with relatively stable prediction errors across individual race/ethnicities [whites (13.9 days), blacks (15.1 days), Hispanics (15.5 days) and Asians (13.1 days)], and correctly identified 75% of preterm births. The model was robust to additional scenarios. CONCLUSIONS: In low-risk, non-obese women, longitudinal FH measures alone can provide a reasonably accurate assessment of GA when ultrasound measures are not available. TWEETABLE ABSTRACT: Longitudinal fundal height alone predicts gestational age at birth when ultrasound measures are unavailable.


Asunto(s)
Antropometría/métodos , Edad Gestacional , Diagnóstico Prenatal/estadística & datos numéricos , Útero/patología , Femenino , Humanos , Recién Nacido , Masculino , Tamaño de los Órganos , Valor Predictivo de las Pruebas , Embarazo , Diagnóstico Prenatal/métodos , Estudios Prospectivos , Estados Unidos
2.
BJOG ; 123(12): 1983-1988, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26853429

RESUMEN

OBJECTIVE: To assess differences in small-for-gestational age (SGA) classifications for the detection of neonates with increased perinatal mortality risk among obese women and subsequently assess the association between prepregnancy body mass index (BMI) status and SGA. DESIGN: Hospital-based cohort. SETTING: Twelve US clinical centres (2002-08). POPULATION: A total of 114 626 singleton, nonanomalous pregnancies. METHODS: Data were collected using electronic medical record abstraction. Relative risks (RR) with 95% CI were estimated. MAIN OUTCOME MEASURES: SGA trends (birthweight < 10th centile) classified using population-based (SGAPOP ), intrauterine (SGAIU ) and customised (SGACUST ) references were assessed. The SGA-associated perinatal mortality risk was estimated among obese women. Using the SGA method most associated with perinatal mortality, the association between prepregnancy BMI and SGA was estimated. RESULTS: The overall perinatal mortality prevalence was 0.55% and this increased significantly with increasing BMI (P < 0.01). Among obese women, SGAIU detected the highest proportion of perinatal mortality cases (2.49%). Perinatal mortality was 5.32 times (95% CI 3.72-7.60) more likely among SGAIU neonates than non-SGAIU neonates. This is in comparison with the 3.71-fold (2.49-5.53) and 4.81-fold (3.41-6.80) increased risk observed when SGAPOP and SGACUST were used, respectively. Compared with women of normal weight, overweight women (RR = 0.82, 95% CI 0.78-0.86) and obese women (RR = 0.80; 95% CI 0.75-0.83) had a lower risk for delivering an SGAIU neonate. CONCLUSION: Among obese women, the intrauterine reference best identified neonates at risk of perinatal mortality. Based on SGAIU , SGA is less common among obese women but these SGA babies are at a high risk of death and remain an important group for surveillance. TWEETABLE ABSTRACT: SGA is less common among obese women but these SGA babies are at a high risk of death.


Asunto(s)
Madres , Mortalidad Perinatal , Peso al Nacer , Estudios de Cohortes , Femenino , Edad Gestacional , Humanos , Lactante , Recién Nacido Pequeño para la Edad Gestacional , Embarazo
3.
BJOG ; 121(9): 1080-8; discussion 1089, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24702952

RESUMEN

OBJECTIVE: Examine whether small-for-gestational-age (SGA) risk factors differed by prior SGA birth. DESIGN: Hospital-based cohort study. SETTING: Utah, USA. POPULATION: Electronic medical record data from 25,241 women who were nulliparous at study entry with ≥2 subsequent consecutive singleton deliveries (2002-2010). METHODS: Estimated adjusted relative risks (RR) and 95% confidence intervals (95% CI) for the association between second pregnancy characteristics and SGA risk. Tested for risk factor differences between recurrence and incidence (Pdifference). MAIN OUTCOME MEASURES: Second pregnancy incident (n = 1067) and recurrent SGA (n = 484) determined using a population-based reference. RESULTS: SGA complicated 20.3 and 4.5% of deliveries to women with and without a prior SGA birth, respectively. Young maternal age (Pdifference = 0.01) and pregnancy hypertensive diseases (Pdifference = 0.03) were associated with incident but not recurrent SGA. Significant risk factors for incidence and recurrence were smoking (incident RR = 1.64 [95% CI 1.22-2.19]; recurrent RR = 1.59 [95% CI 1.17-2.17]), short stature (incident RR = 1.34 [95% CI 1.16-1.54]; recurrent RR = 1.54 [95% CI 1.31-1.82]), prepregnancy underweight (incident RR = 1.32 [95% CI 1.07-1.64]; recurrent RR = 1.30 [95% CI 1.03-1.64]), and inadequate weight gain (incident RR = 1.41 [95% CI 1.22-1.64]; recurrent RR = 1.33 [95% CI 1.10-1.60]). Race-ethnicity, marital or insurance status, alcohol, diabetes, asthma, thyroid disease, depression, or interpregnancy interval were not associated with incidence or recurrence. CONCLUSION: There was considerable overlap in the risk factors for SGA recurrence and incidence. Recurrence and incidence risk factors included smoking, short stature, underweight, and inadequate weight gain. Maternal age and hypertensive diseases increased the risk for incidence only. Regardless of the SGA definition, some potentially modifiable risk factors for recurrence were identified.


Asunto(s)
Recién Nacido Pequeño para la Edad Gestacional , Adolescente , Adulto , Femenino , Humanos , Incidencia , Recién Nacido , Persona de Mediana Edad , Embarazo , Recurrencia , Estudios Retrospectivos , Factores de Riesgo , Utah/epidemiología , Adulto Joven
4.
Int J Obes (Lond) ; 37(2): 237-43, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22310471

RESUMEN

OBJECTIVE: To investigate the influence of adiposity on patterns of sex hormones across the menstrual cycle among regularly menstruating women. SUBJECTS: The BioCycle Study followed 239 healthy women for 1-2 menstrual cycles, with up to eight visits per cycle timed using fertility monitors. METHODS: Serum estradiol (E2), progesterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and sex hormone-binding globulin (SHBG) were measured at each visit. Adiposity was measured by anthropometry and by dual energy X-ray absorptiometry (DXA). Differences in hormonal patterns by adiposity measures were estimated using nonlinear mixed models, which allow for comparisons in overall mean levels, amplitude (i.e., lowest to highest level within each cycle) and shifts in timing of peaks while adjusting for age, race, energy intake and physical activity. RESULTS: Compared with normal weight women (n=154), obese women (body mass index (BMI) 30 kg m(-2), n=25) averaged lower levels of progesterone (-15%, P=0.003), LH (-17%, P=0.01), FSH (-23%, P=0.001) and higher free E2 (+22%, P=0.0001) across the cycle. To lesser magnitudes, overweight women (BMI: 25-30, n=60) also exhibited differences in the same directions for mean levels of free E2, FSH and LH. Obese women experienced greater changes in amplitude of LH (9%, P=0.002) and FSH (8%, P=0.004), but no differences were observed among overweight women. Higher central adiposity by top compared to bottom tertile of trunk-to-leg fat ratio by DXA was associated with lower total E2 (-14%, P=0.005), and FSH (-15%, P=0.001). Peaks in FSH and LH occurred later (∼0.5 day) in the cycle among women with greater central adiposity. CONCLUSION: Greater total and central adiposity were associated with changes in mean hormone levels. The greater amplitudes observed among obese women suggest compensatory mechanisms at work to maintain hormonal homeostasis. Central adiposity may be more important in influencing timing of hormonal peaks than total adiposity.


Asunto(s)
Menstruación/sangre , Obesidad/sangre , Absorciometría de Fotón , Adiposidad , Adulto , Índice de Masa Corporal , Estradiol/sangre , Femenino , Fertilidad , Hormona Folículo Estimulante/sangre , Humanos , Fase Luteínica/sangre , Hormona Luteinizante/sangre , Ciclo Menstrual , Obesidad/complicaciones , Progesterona/sangre , Globulina de Unión a Hormona Sexual/metabolismo
5.
Stat Med ; 31(26): 3241-52, 2012 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-22859290

RESUMEN

Case-control studies are prone to low power for testing gene-environment interactions (GXE) given the need for a sufficient number of individuals on each strata of disease, gene, and environment. We propose a new study design to increase power by strategically pooling biospecimens. Pooling biospecimens allows us to increase the number of subjects significantly, thereby providing substantial increase in power. We focus on a special, although realistic case, where disease and environmental statuses are binary, and gene status is ordinal with each individual having 0, 1, or 2 minor alleles. Through pooling, we obtain an allele frequency for each level of disease and environmental status. Using the allele frequencies, we develop a new methodology for estimating and testing GXE that is comparable to the situation when we have complete data on gene status for each individual. We also explore the measurement process and its effect on the GXE estimator. Using an illustration, we show the effectiveness of pooling with an epidemiologic study, which tests an interaction for fiber and paraoxonase on anovulation. Through simulation, we show that taking 12 pooled measurements from 1000 individuals achieves more power than individually genotyping 500 individuals. Our findings suggest that strategic pooling should be considered when an investigator designs a pilot study to test for a GXE.


Asunto(s)
Bioestadística/métodos , Interacción Gen-Ambiente , Adolescente , Adulto , Arildialquilfosfatasa/sangre , Estudios de Casos y Controles , Estudios de Cohortes , Fibras de la Dieta/administración & dosificación , Frecuencia de los Genes , Hormonas Esteroides Gonadales/sangre , Humanos , Modelos Logísticos , Ciclo Menstrual/sangre , Ciclo Menstrual/genética , Modelos Genéticos , Modelos Estadísticos , Análisis Multivariante , Estudios Prospectivos , Tamaño de la Muestra , Adulto Joven
6.
Stat Med ; 30(12): 1455-65, 2011 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-21264894

RESUMEN

Reference curves are commonly used to identify individuals with extreme values of clinically relevant variables or stages of progression which depend naturally on age or maturation. Estimation of reference curves can be complicated by a technical limit of detection (LOD) that censors the measurement from the left, as is the case in our study of reproductive hormone levels in boys around the time of the onset of puberty. We discuss issues with common approaches to the LOD problem in the context of our pubertal hormone study, and propose a two-part model that addresses these issues. One part of the proposed model specifies the probability of a measurement exceeding the LOD as a function of age. The other part of the model specifies the conditional distribution of a measurement given that it exceeds the LOD, again as a function of age. Information from the two parts can be combined to estimate the identifiable portion (i.e. above the LOD) of a reference curve and to calculate the relative standing of a given measurement above the LOD. Unlike some common approaches to LOD problems, the two-part model is free of untestable assumptions involving unobservable quantities, flexible for modeling the observable data, and easy to implement with existing software. The method is illustrated with hormone data from the Third National Health and Nutrition Examination Survey.


Asunto(s)
Interpretación Estadística de Datos , Límite de Detección , Modelos Estadísticos , Valores de Referencia , Factores de Edad , Niño , Humanos , Inhibinas/sangre , Hormona Luteinizante/sangre , Masculino , Pubertad/fisiología , Testosterona/sangre
7.
Br J Cancer ; 103(9): 1453-61, 2010 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-20924374

RESUMEN

BACKGROUND: Serum cytokine concentrations may reflect inflammatory processes occurring during the development of colorectal neoplasms. Flavonols, bioactive compounds found in plant-based foods and beverages, may inhibit colorectal neoplasms partly by attenuating inflammation. METHODS: Using logistic regression, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) to investigate the association between serum concentrations of interleukin (IL) ß, 2, 8, 10, 12p70, granulocyte macrophage colony stimulating factor, interferon-γ, and tumour necrosis factor-α, measured over time, flavonol intake, estimated from a flavonol database used in conjunction with a food frequency questionnaire, and adenoma recurrence in 872 participants from the intervention arm of the Polyp Prevention Trial. RESULTS: Decreased IL-2 concentration during the trial increased the risk of any adenoma recurrence (4th vs 1st quartile, OR=1.68, 95% CI=1.13-2.49), whereas decreased IL-1ß or IL-10 reduced the risk of advanced adenoma recurrence (OR=0.37, 95% CI=0.15-0.94; OR=0.39, 95% CI=0.15-0.98, respectively). Individuals with flavonol intake above the median (29.7 mg per day) and decreased cytokine concentrations had the lowest risk of advanced adenoma recurrence. CONCLUSION: Overall, no consistent associations were observed between serum cytokine profile and colorectal adenoma recurrence; however, decreased cytokine concentrations during high flavonol consumption may indicate prevention of colorectal neoplasms.


Asunto(s)
Adenoma/sangre , Adenoma/prevención & control , Neoplasias Colorrectales/sangre , Neoplasias Colorrectales/prevención & control , Citocinas/sangre , Flavonoles/administración & dosificación , Anciano , Ensayos Clínicos como Asunto , Dieta , Femenino , Humanos , Interleucinas/sangre , Masculino , Persona de Mediana Edad , Recurrencia
8.
Cytogenet Genome Res ; 129(1-3): 6-16, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20551613

RESUMEN

Maize is a highly diverse species on the gene sequence level. With the recent development of methods to distinguish each of the 10 pairs of homologues in somatic root tip spreads, a wide collection of maize lines was subjected to karyotype analysis to serve as a reference for the community and to examine the spectrum of chromosomal features in the species. The core nested association mapping progenitor collection and additional selections of diversity lines were examined. Commonly used inbred lines were included in the analysis. The centromere 4 specific repeat and ribosomal RNA loci were invariant. The CentC centromere repeat exhibited extensive differences in quantity on any particular chromosome across lines. Knob heterochromatin was highly variable with locations at many sites in the genome. Lastly, representative examples from other species in the genus Zea (teosintes) were examined, which provide information on the evolution of chromosomal features.


Asunto(s)
Cromosomas de las Plantas/genética , Zea mays/genética , Cruzamiento , Centrómero/genética , Pintura Cromosómica , Variaciones en el Número de Copia de ADN , ADN de Plantas/genética , Grano Comestible/clasificación , Grano Comestible/genética , Variación Genética , Heterocigoto , Hibridación Fluorescente in Situ , Especificidad de la Especie , Cariotipificación Espectral , Translocación Genética , Zea mays/clasificación
9.
Science ; 274(5291): 1389-91, 1996 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-8910282

RESUMEN

The Caenorhabditis elegans dauer larva is specialized for dispersal without growth and is formed under conditions of overcrowding and limited food. The daf-7 gene, required for transducing environmental cues that support continuous development with plentiful food, encodes a transforming growth factor-beta (TGF-beta) superfamily member. A daf-7 reporter construct is expressed in the ASI chemosensory neurons. Dauer-inducing pheromone inhibits daf-7 expression and promotes dauer formation, whereas food reactivates daf-7 expression and promotes recovery from the dauer state. When the food/pheromone ratio is high, the level of daf-7 mRNA peaks during the L1 larval stage, when commitment to non-dauer development is made.


Asunto(s)
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans/crecimiento & desarrollo , Proteínas del Helminto/fisiología , Neuronas Aferentes/metabolismo , Factor de Crecimiento Transformador beta/fisiología , Secuencia de Aminoácidos , Animales , Animales Modificados Genéticamente , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Genes de Helminto , Genes Reporteros , Proteínas Fluorescentes Verdes , Proteínas del Helminto/química , Proteínas del Helminto/genética , Humanos , Larva/crecimiento & desarrollo , Larva/metabolismo , Ligandos , Proteínas Luminiscentes/genética , Datos de Secuencia Molecular , Mutación , Fenotipo , Feromonas/farmacología , Temperatura , Factor de Crecimiento Transformador beta/química , Factor de Crecimiento Transformador beta/genética , Transgenes
10.
Bone Marrow Transplant ; 40(6): 573-8, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17637691

RESUMEN

Our purpose was to determine if total body irradiation (TBI) with lung dose reduction protects against subsequent radiation-induced deterioration in pulmonary function. Between July 1997 and August 2004, 181 consecutive patients with hematologic malignancies received fractionated TBI before allogeneic peripheral blood stem cell transplant. The first 89 patients were treated to a total dose of 13.6 Gy. Thereafter, total body dose was decreased to 12 Gy with lung dose reduction to 9 or 6 Gy. All patients underwent pulmonary function test evaluation before treatment, 90 days post-treatment, then annually. Median follow-up was 24.0 months. Eighty-nine patients were treated with lung shielding, and 92 without. At 1-year post transplant, there was a small but significant difference in lung volume measurements between patients with lung shielding and those without. This was not observed at the 2-year time point. When stratified by good (>100% predicted) or poor (

Asunto(s)
Neoplasias Hematológicas/terapia , Enfermedades Pulmonares/etiología , Trasplante de Células Madre de Sangre Periférica , Traumatismos por Radiación/prevención & control , Protección Radiológica , Irradiación Corporal Total/efectos adversos , Adolescente , Adulto , Niño , Femenino , Estudios de Seguimiento , Neoplasias Hematológicas/mortalidad , Humanos , Pulmón/efectos de la radiación , Enfermedades Pulmonares/diagnóstico , Enfermedades Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Traumatismos por Radiación/diagnóstico , Traumatismos por Radiación/mortalidad , Pruebas de Función Respiratoria , Tasa de Supervivencia , Trasplante Homólogo , Irradiación Corporal Total/mortalidad
11.
Prostate Cancer Prostatic Dis ; 10(2): 189-93, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17189954

RESUMEN

Radiation therapy for prostate cancer can cause erectile dysfunction (ED). Intensity Modulated Radiation Therapy (IMRT) can reduce the amount of radiation to surrounding tissues associated with ED. We characterize the incidence of and factors associated with ED in prostate cancer patients after IMRT at the National Naval Medical Center (NNMC). Patients potent by definition of the Sexual Health Inventory for Men (SHIM) before treatment completed the specific erectile questions of the SHIM after IMRT. Statistical analyses were performed to examine the relationships between several factors and ED. Thirty-two of 45 patients with mean age of 68.2 years (50-86 years) completed the SHIM. The median follow-up was 36.8 months (16-63.6 months) as defined by the time from completion of therapy to reassessment with the SHIM. Eight of 32 patients (25%) had no post-treatment ED (SHIM score 22-25), three of 32 (9%) had mild post-treatment ED (SHIM score 17-21), five of 32 (16%) had mild to moderate ED (SHIM score 12-16), five of 32 (16%) had moderate ED (SHIM score 8-11) and 11 of 32 (34%) had severe post-treatment ED (SHIM score<8). Post-treatment potency was significantly associated with the pre-treatment SHIM score (P=0.001) and history of hypertension (P=0.03). The mean radiation dose to the penile bulb and volume of penile bulb treated were not associated with post-treatment potency (P=0.38, 0.76, respectively). IMRT maintains potency in the majority of patients. This analysis compares favorably in preserving erectile function to previously reported series using conventional external beam radiation therapy techniques. The dose of radiation received by the penile bulb and volume of penile bulb were not associated with post-treatment ED in this analysis.


Asunto(s)
Braquiterapia/efectos adversos , Erección Peniana/efectos de la radiación , Neoplasias de la Próstata/radioterapia , Anciano , Anciano de 80 o más Años , Humanos , Masculino , Persona de Mediana Edad , Pene/efectos de la radiación , Dosificación Radioterapéutica
12.
Biotech Histochem ; 81(2-3): 71-8, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16908431

RESUMEN

The signal produced by fluorescence in situ hybridization (FISH) often is inconsistent among cells and sensitivity is low. Small DNA targets on the chromatin are difficult to detect. We report here an improved nick translation procedure for Texas red and Alexa Fluor 488 direct labeling of FISH probes. Brighter probes can be obtained by adding excess DNA polymerase I. Using such probes, a 30 kb yeast transgene, and the rp1, rp3 and zein multigene clusters were clearly detected.


Asunto(s)
Cromosomas de las Plantas , ADN Polimerasa I , Sondas de ADN/síntesis química , Hibridación Fluorescente in Situ/métodos , Técnicas de Sonda Molecular , Zea mays/genética , Hibridación Fluorescente in Situ/instrumentación , Técnicas de Sonda Molecular/instrumentación
13.
J Natl Cancer Inst ; 93(18): 1401-5, 2001 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-11562391

RESUMEN

BACKGROUND: End points for assessing drug activity in brain tumors are determined by measuring the change in tumor size by magnetic resonance imaging (MRI) relative to a pretreatment or best-response scan. Traditionally, two-dimensional (2D) tumor measurements have been used, but one-dimensional (1D) measurements have recently been proposed as an alternative. Because software to estimate three-dimensional (3D) tumor volume from digitized MRI images is available, we compared all three methods of tumor measurement for childhood brain tumors and clinical outcome. METHODS: Tumor size from 130 MRI scans from 32 patients (32 baseline and 98 follow-up scans, for a total of 130 scans; median, three scans per patient; range, two to 18 scans) was measured by each method. Tumor-response category (partial response, minor response, stable disease, or progressive disease) was determined from the percentage change in tumor size between the baseline or best-response scan and follow-up scans. Time to clinical progression was independently determined by chart review. All statistical tests were two-sided. RESULTS: Concordances between 1D and 2D, 1D and 3D, and 2D and 3D were 83% (95% confidence interval [CI] = 67% to 99%), 61% (95% CI = 47% to 75%), and 66% (95% CI = 52% to 80%), respectively, on follow-up scans. Concordances for 1D and 3D and for 2D and 3D were statistically significantly lower than the concordance for 1D and 2D (P< .001 and P = .003, respectively). Concordance among 1D, 2D, and 3D methods in detecting partial response was high; there was less concordance in classifying tumors in the minor response and progressive-disease categories. Median times to progression measured by the 1D, 2D, and 3D methods were 154, 105, and 112 days, respectively, compared with 114 days based on neurologic symptoms and signs (P = .09 for overall comparison). CONCLUSIONS: Detection of partial responses was not influenced by the measurement method, but estimating time to disease progression may be method dependent for childhood brain tumors.


Asunto(s)
Neoplasias Encefálicas/patología , Imagenología Tridimensional , Imagen por Resonancia Magnética/métodos , Neoplasias Encefálicas/mortalidad , Niño , Preescolar , Supervivencia sin Enfermedad , Ependimoma/mortalidad , Ependimoma/patología , Estudios de Seguimiento , Glioma/mortalidad , Glioma/patología , Humanos , Lactante , Sistemas Hombre-Máquina , Meduloblastoma/mortalidad , Meduloblastoma/patología , Programas Informáticos , Resultado del Tratamiento
14.
J Natl Cancer Inst ; 93(23): 1799-805, 2001 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-11734596

RESUMEN

BACKGROUND: Epidemiologic studies have suggested that estrogen may protect against the development of colorectal cancers and adenomatous polyps. We conducted a prospective study to evaluate the association between hormone replacement therapy (HRT) and adenoma recurrence among perimenopausal and postmenopausal women participating in the Polyp Prevention Trial, a randomized dietary intervention study of individuals with colorectal adenomas. METHODS: We used a questionnaire and interviews to collect detailed information, at baseline and at each of four annual study visits, from 620 women regarding hormone use, menopausal status, diet, alcohol consumption, and other risk factors. Adenoma recurrence was ascertained by complete colonoscopy at baseline and after 1 and 4 years. Logistic regression models were used to evaluate the association between hormone use and adenoma recurrence after adjusting for intervention group and for age and body mass index at baseline. All statistical tests were two-sided. RESULTS: Adenomas recurred in 200 women. There was no overall association between adenoma recurrence and either overall hormone use (odds ratio [OR] = 1.01; 95% confidence interval [CI] = 0.70 to 1.45), combined estrogen and progestin use (OR = 0.94; 95% CI = 0.57 to 1.56), or unopposed estrogen use (OR = 1.04; 95% CI = 0.68 to 1.59). HRT use was associated with a reduction in risk for recurrence of distal adenomas (OR = 0.56; 95% CI = 0.32 to 1.00) and a statistically nonsignificant increase in risk for recurrence of proximal adenomas (OR = 1.39; 95% CI = 0.85 to 2.26). We observed a statistically significant interaction between the HRT-adenoma recurrence association and age (P =.02). HRT was associated with a 40% reduced risk of adenoma recurrence among women older than 62 years (OR = 0.58; 95% CI = 0.35 to 0.97) but with an increased risk among women younger than 62 years (OR = 1.99; 95% CI = 1.11 to 3.55). CONCLUSIONS: HRT was not associated with a reduced risk for overall adenoma recurrence in this trial cohort, although there was a suggestion of an age interaction. The effect of age on the association needs to be confirmed in other adenoma recurrence trials.


Asunto(s)
Adenoma/tratamiento farmacológico , Adenoma/prevención & control , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/prevención & control , Terapia de Reemplazo de Hormonas , Recurrencia , Adenoma/patología , Adulto , Factores de Edad , Anciano , Colonoscopía , Neoplasias Colorrectales/patología , Estrógenos/uso terapéutico , Femenino , Humanos , Menopausia , Persona de Mediana Edad , Oportunidad Relativa , Posmenopausia , Progestinas/uso terapéutico , Análisis de Regresión , Factores de Riesgo , Factores de Tiempo
15.
J Natl Cancer Inst ; 93(9): 710-5, 2001 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-11333294

RESUMEN

BACKGROUND: Alcohol ingestion is associated with an increased risk of breast cancer in most epidemiologic studies. Results, however, are heterogeneous at lower levels of alcohol intake, and a biologic mechanism for the association has not been clearly identified. To determine whether alcohol consumption by postmenopausal women elevates serum levels of hormones associated with an increased risk of breast cancer, we performed a controlled feeding study. METHODS: Participants were 51 healthy postmenopausal women not using hormone replacement therapy. Each participant rotated through three 8-week dietary periods in which she consumed 15 or 30 g of alcohol per day or an alcohol-free placebo beverage. The order of assignment to the three alcohol levels was random. During the dietary periods, all food and beverages were supplied by the study, and energy intake was adjusted to keep body weight constant. Levels of estradiol, estrone, estrone sulfate, testosterone, androstenedione, progesterone, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), and androstenediol were measured by radioimmunoassays in serum collected at the end of each dietary period. All statistical tests are two-sided. RESULTS: When women consumed 15 or 30 g of alcohol per day, respectively, estrone sulfate concentrations increased by 7.5% (95% confidence interval [CI] = -0.3% to 15.9%; P =.06) and 10.7% (95% CI = 2.7% to 19.3%; P =.009) and DHEAS concentrations increased by 5.1% (95% CI = 1.4% to 9.0%; P =.008) and 7.5% (95% CI = 3.7% to 11.5%; P<.001) relative to levels when women consumed placebo. None of the other hormones measured changed statistically significantly when women consumed alcohol. CONCLUSIONS: Results suggest a possible mechanism by which consumption of one or two alcoholic drinks per day by postmenopausal women could increase their risk of breast cancer.


Asunto(s)
Neoplasias de la Mama/inducido químicamente , Etanol/efectos adversos , Hormonas Esteroides Gonadales/sangre , Posmenopausia/sangre , Anciano , Deshidroepiandrosterona/sangre , Sulfato de Deshidroepiandrosterona/sangre , Terapia de Reemplazo de Estrógeno , Femenino , Humanos , Persona de Mediana Edad , Globulina de Unión a Hormona Sexual/análisis
16.
J Clin Oncol ; 19(3): 800-11, 2001 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-11157034

RESUMEN

PURPOSE: To determine the feasibility of an organ preservation regimen consisting of infusional paclitaxel administered concurrently with radiotherapy to patients with locally advanced head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS: Thirty-three previously untreated patients with stage III or IV tumors were enrolled onto the study. Paclitaxel was administered as a 120-hour continuous infusion every 3 weeks during the course of radiation therapy. Sixteen patients received a paclitaxel dose of 105 mg/m(2), and 17 patients received 120 mg/m(2). Radiation was delivered in a standard format at 1.8 Gy/d to a total dose of 70.2 to 72 Gy. RESULTS: Three months after therapy, a 76% complete response (CR) at the primary site and a 70% overall CR was achieved. At 36 months, locoregional control was 55.7%, overall survival was 57.8%, and disease-free survival was 51.1%. The median survival duration for all 33 patients was greater than 50 months at the time of this report. Local toxicities including mucositis, dysphagia, and skin reactions were severe but tolerable. All patients retained functional speech, and all but four patients were swallowing food 3 months after treatment. Steady-state plasma concentrations for paclitaxel were not achieved during a 120-hour infusion, suggesting a nonlinear process. Tumor volume quantified by pretreatment computerized tomography imaging was associated with likelihood of response and survival. CONCLUSION: Paclitaxel administered as a 120-hour continuous infusion in combination with radiotherapy is a feasible and promising treatment for patients with advanced HNSCC.


Asunto(s)
Antineoplásicos Fitogénicos/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/radioterapia , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/radioterapia , Paclitaxel/uso terapéutico , Fármacos Sensibilizantes a Radiaciones/uso terapéutico , Adulto , Anciano , Antineoplásicos Fitogénicos/efectos adversos , Antineoplásicos Fitogénicos/farmacocinética , Carcinoma de Células Escamosas/metabolismo , Ciclo Celular/efectos de los fármacos , Ciclo Celular/efectos de la radiación , Terapia Combinada , Deglución/efectos de los fármacos , Deglución/efectos de la radiación , Supervivencia sin Enfermedad , Esquema de Medicación , Femenino , Neoplasias de Cabeza y Cuello/metabolismo , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Paclitaxel/efectos adversos , Paclitaxel/farmacocinética , Proyectos Piloto , Estudios Prospectivos , Fármacos Sensibilizantes a Radiaciones/efectos adversos , Fármacos Sensibilizantes a Radiaciones/farmacocinética , Habla/efectos de los fármacos , Habla/efectos de la radiación , Tasa de Supervivencia
17.
Genetics ; 139(4): 1567-83, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7789761

RESUMEN

The nematode Caenorhabditis elegans responds to conditions of overcrowding and limited food by arresting development as a dauer larva. Genetic analysis of mutations that alter dauer larva formation (daf mutations) is presented along with an updated genetic pathway for dauer vs. nondauer development. Mutations in the daf-2 and daf-23 genes double adult life span, whereas mutations in four other dauer-constitutive genes positioned in a separate branch of this pathway (daf-1, daf-4, daf-7 and daf-8) do not. The increased life spans are suppressed completely by a daf-16 mutation and partially in a daf-2; daf-18 double mutant. A genetic pathway for determination of adult life span is presented based on the same strains and growth conditions used to characterize Daf phenotypes. Both dauer larva formation and adult life span are affected in daf-2; daf-12 double mutants in an allele-specific manner. Mutations in daf-12 do not extend adult life span, but certain combinations of daf-2 and daf-12 mutant alleles nearly quadruple it. This synergistic effect, which does not equivalently extend the fertile period, is the largest genetic extension of life span yet observed in a metazoan.


Asunto(s)
Caenorhabditis elegans/genética , Regulación del Desarrollo de la Expresión Génica , Genes de Helminto , Animales , Caenorhabditis elegans/embriología , Caenorhabditis elegans/fisiología , Heterocigoto , Homocigoto , Longevidad/genética , Mutación , Fenotipo , Reproducción
18.
Genetics ; 150(1): 129-55, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9725835

RESUMEN

The nematode Caenorhabditis elegans responds to overcrowding and scarcity of food by arresting development as a dauer larva, a nonfeeding, long-lived, stress-resistant, alternative third-larval stage. Previous work has shown that mutations in the genes daf-2 (encoding a member of the insulin receptor family) and age-1 (encoding a PI 3-kinase) result in constitutive formation of dauer larvae (Daf-c), increased adult longevity (Age), and increased intrinsic thermotolerance (Itt). Some daf-2 mutants have additional developmental, behavioral, and reproductive defects. We have characterized in detail 15 temperature-sensitive and 1 nonconditional daf-2 allele to investigate the extent of daf-2 mutant defects and to examine whether specific mutant traits correlate with each other. The greatest longevity seen in daf-2 mutant adults was approximately three times that of wild type. The temperature-sensitive daf-2 mutants fell into two overlapping classes, including eight class 1 mutants, which are Daf-c, Age, and Itt, and exhibit low levels of L1 arrest at 25.5 degrees. Seven class 2 mutants also exhibit the class 1 defects as well as some or all of the following: reduced adult motility, abnormal adult body and gonad morphology, high levels of embryonic and L1 arrest, production of progeny late in life, and reduced brood size. The strengths of the Daf-c, Age, and Itt phenotypes largely correlated with each other but not with the strength of class 2-specific defects. This suggests that the DAF-2 receptor is bifunctional. Examination of the null phenotype revealed a maternally rescued egg, L1 lethal component, and a nonconditional Daf-c component. With respect to the Daf-c phenotype, the dauer-defective (Daf-d) mutation daf-12(m20) was epistatic to daf-2 class 1 alleles but not the severe class 2 alleles tested. All daf-2 mutant defects were suppressed by the daf-d mutation daf-16(m26). Our findings suggest a new model for daf-2, age-1, daf-12, and daf-16 interactions.


Asunto(s)
Caenorhabditis elegans/crecimiento & desarrollo , Mutación , Receptor de Insulina/genética , Adaptación Fisiológica , Alelos , Animales , Secuencia de Bases , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiología , Proteínas de Caenorhabditis elegans , Cartilla de ADN , Femenino , Fertilidad , Genes de Helminto , Larva/crecimiento & desarrollo , Masculino , Fenotipo
19.
Eur J Clin Nutr ; 59(2): 161-8, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15367922

RESUMEN

BACKGROUND: Although alcohol intake has been positively associated with breast cancer risk in epidemiologic studies, the mechanisms mediating this association are speculative. OBJECTIVE: The Postmenopausal Women's Alcohol Study was designed to explore the effects of moderate alcohol consumption on potential risk factors for breast cancer. In the present analysis, we evaluated the relationship of alcohol consumption with antioxidant nutrients and a biomarker of oxidative stress. DESIGN: Participants (n=53) consumed a controlled diet plus each of three treatments (15 or 30 g alcohol/day or a no-alcohol placebo beverage), during three 8-week periods in random order. We measured the antioxidants, vitamin E (alpha (alpha)- and gamma (gamma)-tocopherols), selenium, and vitamin C in fasting blood samples which were collected at the end of diet periods, treated and frozen for assay at the end of the study. We also measured 15-F(2t)-IsoP isoprostane, produced by lipid peroxidation, which serves as an indicator of oxidative stress and may serve as a biomarker for conditions favorable to carcinogenesis. RESULTS: After adjusting for BMI (all models) and total serum cholesterol (tocopherol and isoprostane models) we observed a significant 4.6% decrease (P=0.02) in alpha-tocopherol and a marginally significant 4.9% increase (P=0.07) in isoprostane levels when women consumed 30 g alcohol/day (P=0.06 and 0.05 for overall effect of alcohol on alpha-tocopherol and isoprostanes, respectively). The other antioxidants were not significantly modified by the alcohol treatment. CONCLUSIONS: These results suggest that moderate alcohol consumption increases some biomarkers of oxidative stress in postmenopausal women.


Asunto(s)
Consumo de Bebidas Alcohólicas , Antioxidantes/metabolismo , Neoplasias de la Mama/epidemiología , Etanol/administración & dosificación , Isoprostanos/sangre , Estrés Oxidativo/efectos de los fármacos , Posmenopausia/sangre , Consumo de Bebidas Alcohólicas/efectos adversos , Ácido Ascórbico/sangre , Biomarcadores/sangre , Estudios Cruzados , Femenino , Humanos , Peroxidación de Lípido/efectos de los fármacos , Peroxidación de Lípido/fisiología , Persona de Mediana Edad , Estrés Oxidativo/fisiología , Factores de Riesgo , Selenio/sangre , Vitamina E/sangre
20.
Hum Gene Ther ; 12(14): 1713-29, 2001 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-11560766

RESUMEN

Malignant ascites is a common complication of advanced intraabdominal neoplasms for which standard treatments are suboptimal. Evidence suggests that tumor-mediated angiogenesis and enhanced vascular permeability in the peritoneal wall due to high levels of vascular endothelial growth factor play a fundamental role in the pathogenesis of malignant ascites. To explore the advantage of viral vector-mediated "targeted antiangiogenic therapy" in ascites formation, we constructed and administered adenoviral vectors encoding several different antiangiogenic proteins (angiostatin, endostatin, platelet factor 4, and a fusion protein between angiostatin and endostatin) alone or in combination intraperitoneally in mice with peritoneal carcinomatosis from breast cancer (TA3 cells) and ovarian cancer (SKOV-3 i.p. and ES-2 cell lines) to explore the potential of additive or synergistic activity. Our data demonstrated statistically significant downregulation of ascites formation, tumor growth, vascularity, and prolongation of animal survival after intraperitoneal treatment with antiangiogenic adenoviral vectors in three different ascites tumor models. Combined treatment proved to be more effective than treatment with one vector alone. Reduced ascites formation was accompanied by decreased microvascular density in the peritoneal wall and increased apoptosis of tumor cells after administration of antiangiogenic vectors in vivo. Of interest was the observation that AdPF4 caused a significant decrease in the level of VEGF secreted by tumor cells both in vitro and in TA3 ascites tumor-bearing animals in vivo. These data suggest that adenoviral vector-mediated delivery of genes encoding antiangiogenic proteins may represent a potentially new treatment modality for malignant ascites.


Asunto(s)
Ascitis/terapia , Técnicas de Transferencia de Gen , Vectores Genéticos , Neovascularización Patológica/genética , Adenoviridae/genética , Angiostatinas , Animales , Apoptosis , Northern Blotting , Western Blotting , Neoplasias de la Mama/terapia , División Celular , Movimiento Celular , Células Cultivadas , Colágeno/genética , Colorantes/farmacología , Regulación hacia Abajo , Endostatinas , Factores de Crecimiento Endotelial/genética , Endotelio/citología , Endotelio Vascular/citología , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunohistoquímica , Linfocinas/genética , Masculino , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Fragmentos de Péptidos/genética , Plásmidos/metabolismo , Plasminógeno/genética , Factor Plaquetario 4/genética , Proteínas Recombinantes de Fusión/genética , Transducción de Señal , Sales de Tetrazolio/farmacología , Tiazoles/farmacología , Células Tumorales Cultivadas , Venas Umbilicales/citología , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial Vascular
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