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2.
Nat Commun ; 11(1): 4310, 2020 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-32855426

RESUMEN

Electrical pumping of organic semiconductor devices involves charge injection, transport, device on/off dynamics, exciton formation and annihilation processes. A comprehensive model analysing those entwined processes together is most helpful in determining the dominating loss pathways. In this paper, we report experimental and theoretical results of Super Yellow (Poly(p-phenylene vinylene) co-polymer) organic light emitting diodes operating at high current density under high voltage nanosecond pulses. We demonstrate complete exciton and charge carrier dynamics of devices, starting from charge injection to light emission, in a time scale spanning from the sub-ns to microsecond region, and compare results with optical pumping. The experimental data is accurately replicated by simulation, which provides a robust test platform for any organic materials. The universality of our model is successfully demonstrated by its application to three other laser active materials. The findings provide a tool to narrow the search for material and device designs for injection lasing.

3.
Am J Sports Med ; 45(7): 1627-1632, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28297618

RESUMEN

BACKGROUND: Femoroacetabular impingement (FAI) most commonly manifests as anterior groin pain. Patients occasionally have posterior pain but otherwise have clinical and radiographic evidence of FAI. PURPOSE: To compare outcomes of hip arthroscopy for FAI in patients with atypical posterior pain versus a matched group with the typical anterior pain presentation. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients undergoing primary hip arthroscopy for FAI were identified from a clinical repository between January 2012 and 2014. Of 503 patients during the study period, 31 (6.2%) had posterior hip or buttock pain reproduced with flexion, adduction, and internal rotation (FADDIR) and were classified as "atypical," while those with anterior hip or groin pain were classified as "typical." Atypical patients were matched in a 1:2 cohort to the typical group based on sex, age, and body mass index (BMI). Postoperative patient-reported outcomes included visual analog scale (VAS) for pain, modified Harris Hip Score (mHHS), and Hip Outcome Scores with Activities of Daily Living (HOS-ADL) and Sports-Specific (HOS-SS) subscales. RESULTS: Of the 31 atypical patients, 28 (90.3%) were available for a minimum 2-year follow-up (mean ± SD, 2.6 ± 0.6 years). These patients were matched with 56 typical patients. No differences were noted between typical and atypical cohorts in preoperative demographic or radiographic parameters. Postoperatively, both groups demonstrated significant improvements in mHHS (atypical 60.1 ± 12.4 to 78.8 ± 12.9; typical 60.0 ± 12.3 to 76.9 ± 13.6; P < .001), HOS-ADL (atypical 68.5 ± 17.0 to 88.6 ± 11.0; typical 69.2 ± 17.1 to 86.8 ± 14.7; P < .001), and HOS-SS (atypical 42.0 ± 25.5 to 71.0 ± 26.2; typical 44.4 ± 24.9 to 71.3 ± 27.3; P < .001). No differences were found in 2-year score improvements between the atypical and typical cohorts (mHHS 18.7 ± 13.4 vs 16.9 ± 13.1, P = .48; HOS-ADL 20.1 ± 16.8 vs 17.6 ± 14.6, P = .19; HOS-SS 29.0 ± 30.2 vs 26.9 ± 27.3, P = .93). Also, no significant differences were found in VAS pain improvement (5.0 ± 3.2 vs 5.6 ± 2.8, P = .56) or postoperative satisfaction (79.5 ± 5.5 vs 77.5 ± 4.1, P = .78). CONCLUSION: Atypical posterior hip pain is an uncommon presentation of FAI. Patients demonstrate similar significant improvements after hip arthroscopy in outcome scores, postoperative pain, and satisfaction compared with patients who have classic anterior groin pain.


Asunto(s)
Artralgia/cirugía , Artroscopía , Pinzamiento Femoroacetabular/cirugía , Actividades Cotidianas , Adulto , Artralgia/etiología , Artralgia/prevención & control , Estudios de Cohortes , Femenino , Pinzamiento Femoroacetabular/complicaciones , Pinzamiento Femoroacetabular/diagnóstico por imagen , Articulación de la Cadera/cirugía , Humanos , Masculino , Análisis por Apareamiento , Dimensión del Dolor , Radiografía , Rango del Movimiento Articular , Resultado del Tratamiento , Escala Visual Analógica
4.
Int J Pediatr ; 2014: 819872, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25435883

RESUMEN

Objective. To evaluate parental attitudes toward providing foods and beverages with nonnutritive sweeteners (NNS) to their children and to explore parental ability to recognize NNS in packaged foods and beverages. Methods. 120 parents of children ≥ 1 and ≤18 years of age completed brief questionnaires upon entering or exiting a grocery store. Parental attitudes toward NNS were assessed using an interviewer-assisted survey. Parental selection of packaged food and beverages (with and without NNS) was evaluated during a shopping simulation activity. Parental ability to identify products with NNS was tested with a NNS recognition test. Results. Most parents (72%) disagreed with the statement "NNS are safe for my child to consume." This was not reflected during the shopping simulation activity because about one-quarter of items selected by parents contained NNS. Parents correctly identified only 23% of NNS-containing items presented as foods or beverages which were sweetened with NNS. Conclusions. The negative parental attitudes toward providing NNS to their children raise the question whether parents are willing to replace added sugars with NNS in an effort to reduce their child's calorie intake. Our findings also suggest that food labeling should be revised in order for consumers to more easily identify NNS in foods and beverages.

5.
Prog Neuropsychopharmacol Biol Psychiatry ; 35(6): 1421-31, 2011 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-21122812

RESUMEN

Zebrafish (Danio rerio) are becoming increasingly popular in neurobehavioral research. Here, we summarize recent data on behavioral responses of adult zebrafish to a wide spectrum of putative anxiolytic and anxiogenic agents. Using the novel tank test as a sensitive and efficient behavioral assay, zebrafish anxiety-like behavior can be bi-directionally modulated by drugs affecting the gamma-aminobutyric acid, monoaminergic, cholinergic, glutamatergic and opioidergic systems. Complementing human and rodent data, zebrafish drug-evoked phenotypes obtained in this test support this species as a useful model for neurobehavioral and psychopharmacological research.


Asunto(s)
Ansiolíticos/farmacología , Ansiolíticos/uso terapéutico , Ansiedad/tratamiento farmacológico , Modelos Animales de Enfermedad , Transmisión Sináptica/efectos de los fármacos , Animales , Ansiedad/inducido químicamente , Conducta Exploratoria/efectos de los fármacos , Humanos , Fenotipo , Pez Cebra
6.
J Low Genit Tract Dis ; 10(4): 229-37, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17012988

RESUMEN

OBJECTIVE: Cohort studies of the natural history of human papillomavirus (HPV) infection and cervical squamous intraepithelial lesions with repeated screening allow the comparison of different macroscopic and microscopic diagnostic methods. MATERIALS AND METHODS: Concurrent visual inspection using cervicography and conventional Pap cytology tests were performed during multiple visits in a cohort of women attending a maternal and child health clinic in São Paulo, Brazil. HPV infection status at the same visits was determined by polymerase chain reaction followed by typing with specific oligonucleotide probing and viral load quantification. Information on reproductive health and hygiene habits was also collected at each visit. RESULTS: Overall agreement between cervicography and cytology was low (kappa = 0.046), which increased only slightly when high oncogenic-risk HPV types (kappa = 0.120) or high viral burden (>100 copies/cell) (kappa = 0.170) was present. Analysis of reproductive health and hygiene habits revealed somewhat different risk factors for cervical lesions detected by these tests. However, presence of oncogenic HPV DNA (odds ratio = 36.0, 95% CI = 16.6-77.8) and high viral burden (odds ratio = 67.34; 95% CI = 27.1-167.0) were strongly associated with lesions detected by cytology but not by cervicography. CONCLUSIONS: Although changes in the cervix (because of age, gravidity, or hormonal effects) may influence the performance of morphology-based screening tests, the lack of agreement and the different degrees of association with HPV infection measures indicate that a visual inspection method such as cervicography may detect different cervical abnormalities relative to cytology.


Asunto(s)
Papillomavirus Humano 16/aislamiento & purificación , Papillomavirus Humano 18/aislamiento & purificación , Infecciones por Papillomavirus , Vagina/diagnóstico por imagen , Frotis Vaginal/métodos , Carga Viral , Adolescente , Adulto , Anciano , ADN Viral/análisis , Femenino , Estudios de Seguimiento , Papillomavirus Humano 16/genética , Papillomavirus Humano 18/genética , Humanos , Persona de Mediana Edad , Variaciones Dependientes del Observador , Infecciones por Papillomavirus/diagnóstico , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/virología , Reacción en Cadena de la Polimerasa , Radiografía , Vagina/patología
7.
Cancer Res ; 63(21): 7215-20, 2003 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-14612516

RESUMEN

The distributions of human papillomavirus (HPV) types detected in cervical adenocarcinomas and squamous cell tumors differ. However, whether the distributions of intratypic HPV variants seen in these two histological forms of cervical disease differ is unknown. Our objective was to compare the distribution of HPV intratypic variants observed in squamous cell carcinomas (SCC) and cervical tumors of glandular origin (e.g., adenocarcinomas; AC) for two HPV types commonly observed in cervical tumors, HPV16 and HPV18. Participants in a multicenter case-control study of AC and SCC conducted in the eastern United States were studied. A total of 85 HPV16 and/or HPV18 positive individuals (31 diagnosed with AC, 43 diagnosed with SCC, and 11 population controls) were included. For HPV16-positive individuals, both the noncoding long control region and the E6 open reading frame were sequenced, and classified into phylogenetic-based lineage groups (European, Asian-American, African1, and African2). For HPV18-positive individuals, the long control region region only was sequenced and classified into known intratypic lineages (European, Asian-Amerindian, and African). The distribution of these different intratypic lineages among AC cases, SCC cases, and population controls was compared using standard methods. Non-European HPV16 and/or HPV18 intratypic variants were observed in 42% of ACs compared with 16% of SCCs and 18% of population controls (P = 0.04). Intratypic variants from the Asian-American lineage of HPV16 accounted for the differences seen between histological groups. The differences observed between AC and SCC cases were strongest for HPV16, and persisted in analysis restricted to Caucasian women, suggesting that the effect cannot be explained by differences in the ethnic make-up of AC versus SCC cases. Cervical AC and SCC differ not only with respect to the distribution of HPV types detected but also with respect to intratypic variants observed. Non-European HPV16 and/or HPV18 variants are commonly seen in AC. A possible hormonal mechanism is suggested to explain the observed findings.


Asunto(s)
Adenocarcinoma/virología , Carcinoma de Células Escamosas/virología , Papillomaviridae/clasificación , Infecciones por Papillomavirus/virología , Infecciones Tumorales por Virus/virología , Neoplasias del Cuello Uterino/virología , Adenocarcinoma/epidemiología , Carcinoma de Células Escamosas/epidemiología , Estudios de Casos y Controles , Etnicidad , Femenino , Humanos , Papillomaviridae/genética , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Infecciones Tumorales por Virus/complicaciones , Infecciones Tumorales por Virus/epidemiología , Estados Unidos/epidemiología , Neoplasias del Cuello Uterino/epidemiología
8.
Cancer Epidemiol Biomarkers Prev ; 12(9): 815-23, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-14504189

RESUMEN

Increased understanding of human papillomavirus (HPV) infection as the central cause of cervical cancer has permitted the development of improved screening techniques. To evaluate their usefulness, we evaluated the performance of multiple screening methods concurrently in a large population-based cohort of >8500 nonvirginal women without hysterectomies, whom we followed prospectively in a high-risk region of Latin America. Using Youden's index as a measure of the trade-off between sensitivity and specificity, we estimated the performances of a visual screening method (cervicography), conventional cytology, liquid-based cytology (ThinPrep), and DNA testing for 13 oncogenic HPV types. The reference standard of disease was neoplasia > or = cervical intraepithelial neoplasia grade 3 (CIN 3), defined as histologically confirmed CIN 3 detected within 2 years of enrollment (n=90) or invasive cancer detected within 7 years (n=20). We analyzed each technique alone and in paired combinations (n=112 possible strategies), and evaluated the significance of differences between strategies using a paired Z test that equally weighted sensitivity and specificity. As a single test, either liquid-based cytology or HPV DNA testing was significantly more accurate than conventional cytology or cervicography. Paired tests incorporating either liquid-based cytology or HPV DNA testing were not substantially more accurate than either of those two test strategies alone. However, a possibly useful synergy was observed between the conventional smear and cervicography. Consideration of age or behavioral risk profiles did not alter any of these conclusions. Overall, we conclude that highly accurate screening for cervical cancer and CIN 3 is now technically feasible. The remaining vital issue is to extend improved cervical cancer prevention programs to resource-poor regions.


Asunto(s)
Tamizaje Masivo/métodos , Papillomaviridae , Infecciones Tumorales por Virus/diagnóstico , Neoplasias del Cuello Uterino/diagnóstico , Adolescente , Adulto , Anciano , Estudios de Cohortes , Costa Rica , ADN Viral/análisis , Femenino , Humanos , Tamizaje Masivo/economía , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/virología , Estudios Prospectivos , Factores de Riesgo , Sensibilidad y Especificidad , Infecciones Tumorales por Virus/epidemiología , Neoplasias del Cuello Uterino/epidemiología , Neoplasias del Cuello Uterino/virología , Frotis Vaginal , Displasia del Cuello del Útero/diagnóstico , Displasia del Cuello del Útero/epidemiología
9.
Cancer ; 98(4): 814-21, 2003 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-12910527

RESUMEN

BACKGROUND: Hormonal factors may play a more prominent role in cervical adenocarcinoma than squamous cell carcinoma. The authors evaluated whether obesity, which can influence hormone levels, was associated with adenocarcinoma and squamous cell carcinoma. METHODS: This case-control study included 124 patients with adenocarcinoma, 139 matched patients with squamous cell carcinoma, and 307 matched community control participants. All participants completed interviews and provided cervicovaginal samples for human papillomavirus (HPV) testing. Polytomous logistic regression-generated odds ratios (ORs) and 95% confidence intervals (95% CIs) for self-reported height and weight, body mass index (BMI; kg/m(2)), and measured waist-to-hip ratio (WHR) for both histologic types were adjusted and stratified for HPV and other confounders. RESULTS: Height, weight, BMI, and WHR were positively associated with adenocarcinoma. BMI >or= 30 kg/m(2) (vs. BMI < 25 kg/m(2); OR, 2.1 and 95% CI, 1.1-3.8) and WHR in the highest tertile (vs. the lowest tertile; OR, 1.8 and 95% CI, 0.97-3.3) were associated with adenocarcinoma. Neither height nor weight was found to be associated with squamous cell carcinoma, and associations for BMI >or= 30 kg/m(2) (OR, 1.6) and WHR in the highest tertile (OR, 1.6) were weaker and were not statistically significant. Analyses using only HPV positive controls showed similar associations. The data were adjusted for and stratified by screening, but higher BMI and WHR were associated with higher disease stage at diagnosis, even among recently and frequently screened patients with adenocarcinoma. Thus, residual confounding by screening could not be excluded as an explanation for the associations. CONCLUSIONS: Obesity and body fat distribution were associated more strongly with adenocarcinoma than with squamous cell carcinoma. Although questions about screening remain, obesity may have a particular influence on the risk of glandular cervical carcinoma.


Asunto(s)
Adenocarcinoma/etiología , Carcinoma de Células Escamosas/etiología , Obesidad/complicaciones , Neoplasias del Cuello Uterino/etiología , Adenocarcinoma/virología , Adolescente , Adulto , Anciano , Constitución Corporal , Estatura , Índice de Masa Corporal , Peso Corporal , Carcinoma de Células Escamosas/virología , Estudios de Casos y Controles , Cuello del Útero/virología , ADN Viral/análisis , Femenino , Humanos , Modelos Logísticos , Persona de Mediana Edad , Oportunidad Relativa , Papillomaviridae/aislamiento & purificación , Factores de Riesgo , Neoplasias del Cuello Uterino/virología
10.
Am J Obstet Gynecol ; 188(3): 657-63, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12634637

RESUMEN

OBJECTIVE: Although human papillomavirus causes essentially all cervical carcinoma, cofactors may differ by cancer histologic type. We examined human papillomavirus genotypes and sexual and reproductive risk factors for cervical adenocarcinoma and squamous cell carcinoma. STUDY DESIGN: One hundred twenty-four women with adenocarcinoma, 139 women with squamous cell carcinoma, and 307 control subjects participated in this case-control study. Logistic regression analyses were performed to calculate odds ratios and CIs. RESULTS: Human papillomavirus 18 was associated most strongly with adenocarcinoma (odds ratio, 105; 95% CI, 23-487). Human papillomavirus 16 was associated most strongly with squamous cell carcinoma (odds ratio, 30; 95% CI, 12-77). More than three lifetime sexual partners was a risk factor for adenocarcinoma (odds ratio, 2.1; 95% CI, 1.1-4.0) and squamous cell carcinoma (odds ratio, 3.0; 95% CI, 1.6-5.9). Even being pregnant was associated inversely with adenocarcinoma (odds ratio, 0.4; 95% CI, 0.2-0.8). Five or more pregnancies was associated with squamous cell carcinoma (odds ratio, 2.2; 95% CI, 0.9-5.4). CONCLUSION: The relative importance of human papillomavirus genotypes 16 and 18 and the reproductive co-factor differences suggest distinct causes for cervical adenocarcinoma and squamous cell carcinoma.


Asunto(s)
Adenocarcinoma/etiología , Carcinoma de Células Escamosas/etiología , Registros Médicos , Papillomaviridae/genética , Reproducción , Sexo Seguro , Neoplasias del Cuello Uterino/etiología , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Genotipo , Humanos , Persona de Mediana Edad , New England , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/complicaciones , Embarazo , Infecciones Tumorales por Virus/complicaciones
11.
J Infect Dis ; 186(5): 598-605, 2002 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-12195346

RESUMEN

To comprehensively explore the relationship between human leukocyte antigen (HLA) class I alleles and cervical neoplasia, a subset of participants from 3 large US and Costa Rican cervix studies were typed for HLA class I alleles. Study subjects were women with cervical cancer or high-grade squamous epithelial lesions (HSILs; n=365) or low-grade squamous epithelial lesions (LSILs; n=275) or who were cytologically normal (control subjects; n=681). Allele-disease associations were assessed by logistic regression analysis. Consistent associations across all studies were observed for HLA-CW*0202 with a combined odds ratio of 0.53 (95% confidence interval [CI], 0.29-0.89) for cancer or HSILs and 0.58 (95% CI, 0.37-1.04) for LSILs, compared with control subjects and adjusted for study. This finding supports the hypothesis that a single allele may be sufficient to confer protection against cervical neoplasia. Given the relationship between HLA-C and its receptors on natural killer (NK) cells, a role is proposed for NK function in human papillomavirus infection and cervical neoplasia.


Asunto(s)
Alelos , Carcinoma de Células Escamosas/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Neoplasias del Cuello Uterino/inmunología , Carcinoma de Células Escamosas/epidemiología , Carcinoma de Células Escamosas/virología , Estudios de Cohortes , Costa Rica , ADN Viral/química , ADN Viral/genética , Femenino , Antígenos HLA-C/genética , Antígenos HLA-C/inmunología , Antígenos de Histocompatibilidad Clase I/genética , Humanos , Modelos Logísticos , Oregon , Papillomaviridae/genética , Papillomaviridae/inmunología , Infecciones por Papillomavirus/genética , Infecciones por Papillomavirus/inmunología , Reacción en Cadena de la Polimerasa , Infecciones Tumorales por Virus/genética , Infecciones Tumorales por Virus/inmunología , Neoplasias del Cuello Uterino/epidemiología , Neoplasias del Cuello Uterino/virología
12.
Am J Obstet Gynecol ; 187(1): 15-23, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12114883

RESUMEN

OBJECTIVE: The purpose of this study was to estimate the optimal performance of cervicography. We compared an arbitrated cervigram classification with an arbitrated referent diagnosis of cervical neoplasia. STUDY DESIGN: From an initial group of 8460 women, a stratified sample of cervigrams from 3645 women and histologic information from 414 women underwent arbitration. Interobserver agreement was assessed for cervicography and the referent diagnosis. Sensitivity, specificity, and predictive values were estimated for initial and arbitrated cervicography results, compared with the initial and arbitrated referent diagnoses. RESULTS: For the detection of arbitrated high-grade lesions or cancer, arbitrated cervicography yielded an overall sensitivity of 63.9% and a specificity of 93.7%. Significantly higher sensitivity was associated with younger age and age-related visual characteristics. CONCLUSION: Optimization of the cervigram classification improved performance over a single interpretation in this population but suggested the limits of static visual screening.


Asunto(s)
Fotograbar , Neoplasias del Cuello Uterino/diagnóstico , Colposcopía , Femenino , Estudios de Seguimiento , Humanos , Variaciones Dependientes del Observador , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Displasia del Cuello del Útero/diagnóstico , Displasia del Cuello del Útero/patología , Neoplasias del Cuello Uterino/patología
14.
Cancer Epidemiol Biomarkers Prev ; 11(1): 3-6, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11815394

RESUMEN

Human papillomaviruses (HPVs) play a central role in the development of cervical carcinoma. Plasma DNA from 232 patients taken at diagnosis or after treatment for invasive cervical cancer (n = 175) or carcinoma in situ (n = 57) and 60 normal controls were examined for HPV-16 or HPV-18 E7 DNA by conventional and real-time quantitative PCR assays. We found HPV-16 or HPV-18 E7 DNA in 6.9% (11 of 175) of invasive cervical cancer cases (18.1% of cases positive for HPV-16 or HPV-18 at the genital tract), 1.8% (1 of 57) of carcinoma in situ, and 1.7% (1 of 60) of normal controls by conventional PCR. Quantitative PCR identified the highest concentrations of HPV DNA (copy number of HPV/ml of plasma) in patients with invasive cervical cancer (mean, 11,163; median, 183.5), followed by a level of 8 in the single carcinoma in situ case and 0 copies in the normal control initially positive by conventional PCR. HPV DNA can be detected in the plasma of some patients with HPV-positive cervical tumors. It remains to be demonstrated whether quantitative PCR analysis of HPV DNA in plasma may have utility in patients at high risk of recurrent disease.


Asunto(s)
ADN Viral/análisis , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/diagnóstico , Infecciones Tumorales por Virus/diagnóstico , Neoplasias del Cuello Uterino/virología , Adenocarcinoma/diagnóstico , Adenocarcinoma/virología , Secuencia de Bases , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/virología , Estudios de Casos y Controles , Femenino , Humanos , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Valores de Referencia , Estudios Retrospectivos , Sensibilidad y Especificidad , Neoplasias del Cuello Uterino/diagnóstico
15.
Rev. panam. salud pública ; 1(5): 362-374, mayo 1997. ilus
Artículo en Inglés | LILACS | ID: lil-201365

RESUMEN

En el presente trabajo se describe la fase de reclutamiento de un estudio poblacional sobre la historia natural de las neoplasias de cuello uterino en Guanacaste, provincia rural costarricense donde las tasas de cáncer cervicouterino invasor son invariablemente altas. Las metas principales del estudio son investigar el papel que desempeñan la infección por el virus del papiloma humano (VPH) y sus cofactores en la etiología de las neoplasias cervicouterinas de alto grado, y evaluar las nuevas tecnologías empleadas en el tamizaje del cáncer cervical. Para empezar se seleccionó una muestra aleatoria de segmentos censuales y, con la ayuda de trabajadores de acción comunitaria del Ministerio de Salud de Costa Rica, se hizo un recuento de todas las habitantes de 18 años de edad o mayores. De las 10 738 mujeres que cumplían con los requisitos para participar, 10 049 (93,6%) fueron entrevistadas después de haber dado su consentimiento informado por escrito. Después de la entrevista sobre los factores de riesgo del cáncer cervicouterino, se hizo un examen pélvico a las mujeres que dijeron haber tenido actividad sexual. El examen pélvico incluyó la determinación del pH vaginal y la obtención de células para análisis citológico mediante tres técnicas distintas. También se obtuvieron células cervicales para determinar la presencia y cantidad de ADN de 16 tipos de VPH diferentes y se tomaron dos fotografías del cérvix que fueron interpretadas en un local distinto por un experto en colposcopia. Por último, se sacaron muestras de sangre para hacer ensayos inmunológicos y determinaciones de micronutrientes. Las mujeres con un diagnóstico citológico anormal o un cervigrama positivo, más una muestra del grupo en general, fueron remitidas para hacerles colposcopia y se tomaron biopsias cuando se observaron lesiones. El tamizaje con fines de reclutamiento servirá de base para un estudio de prevalencia de casos y controles, y las integrantes de la cohorte sin enfermedad avanzada tendrán un seguimiento activo a intervalos mínimos de un año, con el propósito de estudiar la historia natural de la infección por VPH y los orígenes de las lesiones escamosas intraepiteliales de alto grado. Se describe en detalle la operación de campo y se hace especial alusión a la realización de estudios de este tipo en países en desarrollo. También se presentan datos descriptivos sobre la prevalencia de la enfermedad y la exposición a diversos factores de riesgo


This paper reports on the enrollment phase of a population-based natural history study of cervical neoplasia in Guanacaste, a rural province of Costa Rica with consistently high rates of invasive cervical cancer. The main goals of the study are to investigate the role of human papillomavirus (HPV) infection and its co-factors in the etiology of high-grade cervical neoplasia, and to evaluate new cervical cancer screening technologies. To begin, a random sample of censal segments was selected and enumeration of all resident women 18 years of age and over was conducted with the aid of outreach workers of the Costa Rican Ministry of Health. Of the 10 738 women who were eligible to participate, 10 049 (93.6%) were interviewed after giving written informed consent. After the interview on cervical cancer risk factors was administered, a pelvic examination was performed on those women who reported previous sexual activity. The pelvic examination included a vaginal pH determination and collection of cervical cells for cytologic diagnosis using three different techniques. Additional cervical cells were collected for determination of the presence and amount of DNA from 16 different types of HPV, and two photographic images of the cervix were taken and interpreted offsite by an expert colposcopist. Finally, blood samples were collected for immunologic and micronutrient assays. Women with any abnormal cytologic diagnosis or a positive Cervigram, as well as a sample of the whole group, were referred for colposcopy, and biopsies were taken when lesions were observed. The enrollment screening will serve as the basis for a prevalent case-control study, and the members of the cohort free from serious disease will be followed actively, at intervals of no more than a year, to study the natural history of HPV infection and the origins of high-grade squamous intraepithelial lesions (HSIL). Details of the field operation are outlined, with particular reference to the realization of this kind of study in developing countries. Descriptive data on the prevalence of disease and exposure to various risk factors are also presented.


Asunto(s)
Humanos , Femenino , Adulto , Persona de Mediana Edad , Papillomaviridae , ADN de Neoplasias , Neoplasias del Cuello Uterino , Infecciones por Papillomavirus/etiología , Estudios de Casos y Controles , Recolección de Datos/métodos , Técnicas Citológicas
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