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1.
Pharmacogenomics J ; 15(5): 422-9, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25601762

RESUMEN

Asthma is a chronic lung disease that has a high prevalence. The therapeutic intervention of this disease can be made more effective if genetic variability in patients' response to medications is implemented. However, a clear picture of the genetic architecture of asthma intervention response remains elusive. We conducted a genome-wide association study (GWAS) to identify drug response-associated genes for asthma, in which 909 622 SNPs were genotyped for 120 randomized participants who inhaled multiple doses of glucocorticoids. By integrating pharmacodynamic properties of drug reactions, we implemented a mechanistic model to analyze the GWAS data, enhancing the scope of inference about the genetic architecture of asthma intervention. Our pharmacodynamic model observed associations of genome-wide significance between dose-dependent response to inhaled glucocorticoids (measured as %FEV1) and five loci (P=5.315 × 10(-7) to 3.924 × 10(-9)), many of which map to metabolic genes related to lung function and asthma risk. All significant SNPs detected indicate a recessive effect, at which the homozygotes for the mutant alleles drive variability in %FEV1. Significant associations were well replicated in three additional independent GWAS studies. Pooled together over these three trials, two SNPs, chr6 rs6924808 and chr11 rs1353649, display an increased significance level (P=6.661 × 10(-16) and 5.670 × 10(-11)). Our study reveals a general picture of pharmacogenomic control for asthma intervention. The results obtained help to tailor an optimal dose for individual patients to treat asthma based on their genetic makeup.


Asunto(s)
Asma/genética , Estudio de Asociación del Genoma Completo , Glucocorticoides/administración & dosificación , Polimorfismo de Nucleótido Simple/genética , Adulto , Asma/tratamiento farmacológico , Asma/patología , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Farmacogenética
2.
Pharmacogenomics J ; 14(1): 41-7, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23508266

RESUMEN

Reversibility of airway obstruction in response to ß2-agonists is highly variable among asthmatics, which is partially attributed to genetic factors. In a genome-wide association study of acute bronchodilator response (BDR) to inhaled albuterol, 534 290 single-nucleotide polymorphisms (SNPs) were tested in 403 white trios from the Childhood Asthma Management Program using five statistical models to determine the most robust genetic associations. The primary replication phase included 1397 polymorphisms in three asthma trials (pooled n=764). The second replication phase tested 13 SNPs in three additional asthma populations (n=241, n=215 and n=592). An intergenic SNP on chromosome 10, rs11252394, proximal to several excellent biological candidates, significantly replicated (P=1.98 × 10(-7)) in the primary replication trials. An intronic SNP (rs6988229) in the collagen (COL22A1) locus also provided strong replication signals (P=8.51 × 10(-6)). This study applied a robust approach for testing the genetic basis of BDR and identified novel loci associated with this drug response in asthmatics.


Asunto(s)
Agonistas de Receptores Adrenérgicos beta 2/uso terapéutico , Asma/tratamiento farmacológico , Broncodilatadores/uso terapéutico , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Adolescente , Agonistas de Receptores Adrenérgicos beta 2/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Asma/genética , Broncodilatadores/administración & dosificación , Niño , Preescolar , Ensayos Clínicos como Asunto , Femenino , Estudio de Asociación del Genoma Completo , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Adulto Joven
3.
Nat Genet ; 5(4): 408-12, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8298652

RESUMEN

We have examined the imprinting of the insulin-like growth factor II gene (IGF2) in ten normal kidney samples from children with renal embryonal neoplasms. In kidney samples from nine children with normal growth profiles, IGF2 mRNA was transcribed monoallelically, consistent with normal imprinting of the gene. But in one child who had generalized somatic overgrowth, IGF2 was transcribed from both alleles in her kidney, peripheral blood leukocytes and Wilms' tumour. These findings suggest that a defect in genomic imprinting can occur constitutionally, leading to growth abnormalities and predisposition to Wilms' tumour.


Asunto(s)
Genes del Tumor de Wilms , Gigantismo/genética , Factor II del Crecimiento Similar a la Insulina/metabolismo , Neoplasias Renales/genética , Alelos , Humanos , Factor II del Crecimiento Similar a la Insulina/genética , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , ARN Mensajero/metabolismo
4.
Clin Exp Allergy ; 42(12): 1724-33, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23181788

RESUMEN

BACKGROUND: Asthma is a common chronic respiratory disease in children and adults. An important genetic component to asthma susceptibility has long been recognized, most recently through the identification of several genes (e.g., ORMDL3, PDE4D, HLA-DQ, and TLE4) via genome-wide association studies. OBJECTIVE: To identify genetic variants associated with asthma affection status using genome-wide association data. METHODS: We describe results from a genome-wide association study on asthma performed in 3855 subjects using a panel of 455 089 single nucleotide polymorphisms (SNPs). RESULT: The genome-wide association study resulted in the prioritization of 33 variants for immediate follow-up in a multi-staged replication effort. Of these, a common polymorphism (rs9272346) localizing to within 1 Kb of HLA-DQA1 (chromosome 6p21.3) was associated with asthma in adults (P-value = 2.2E-08) with consistent evidence in the more heterogeneous group of adults and children (P-value = 1.0E-04). Moreover, some genes identified in prior asthma GWAS were nominally associated with asthma in our populations. CONCLUSION: Overall, our findings further replicate the HLA-DQ region in the pathogenesis of asthma. HLA-DQA1 is the fourth member of the HLA family found to be associated with asthma, in addition to the previously identified HLA-DRA, HLA-DQB1 and HLA-DQA2.


Asunto(s)
Asma/genética , Predisposición Genética a la Enfermedad , Antígenos HLA-DQ/genética , Cadenas alfa de HLA-DQ/genética , Polimorfismo de Nucleótido Simple , Adolescente , Adulto , Anciano , Asma/epidemiología , Asma/fisiopatología , Niño , Preescolar , Ensayos Clínicos como Asunto , Femenino , Estudio de Asociación del Genoma Completo , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
5.
J Clin Oncol ; 6(12): 1845-50, 1988 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3058876

RESUMEN

Fifty-three children with Hodgkin's disease were clinically staged and treated with chemotherapy alone. Forty-six received mechlorethamine (Mustargen; Merk Sharpe & Dohme, West Point, PA), vincristine (Oncovin; Eli Lilly and Company, Indianapolis), procarbazine, and prednisolone (MOPP) and 7 chlorambucil, vinblastine, prednisolone, and procarbazine (ChlVPP). There were four events in the 38 children with stage I and II disease. One patient with massive mediastinal disease failed to remit and subsequently failed mantle irradiation and changes of chemotherapy. Another relapsed at the site of local disease and was salvaged with involved field irradiation and further courses of MOPP. Two other children died as a result of acute graft-v-host disease (GVHD) following transfusion. At autopsy there was no evidence of Hodgkin's disease. Fifteen children had stage III and IV disease and 14 achieved complete remission (CR) and none have relapsed. The child who failed to achieve remission died of virus infections. A mediastinal mass greater than 1/3 the thoracic width was present in 19 children of whom 18 achieved remission and none relapsed. An infradiaphragmatic presentation occurred in eight, all achieved remission and none relapsed. Overall at a median follow-up time of 45 months survival was 94%; the percent of patients without treatment failure was 92; and the percent without relapse was 98.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Enfermedad de Hodgkin/tratamiento farmacológico , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Niño , Preescolar , Clorambucilo/administración & dosificación , Clorambucilo/efectos adversos , Ensayos Clínicos como Asunto , Femenino , Enfermedad de Hodgkin/mortalidad , Humanos , Masculino , Mecloretamina/administración & dosificación , Mecloretamina/efectos adversos , Estadificación de Neoplasias , Prednisolona/administración & dosificación , Prednisolona/efectos adversos , Prednisona/administración & dosificación , Prednisona/efectos adversos , Procarbazina/administración & dosificación , Procarbazina/efectos adversos , Vinblastina/administración & dosificación , Vinblastina/efectos adversos , Vincristina/administración & dosificación , Vincristina/efectos adversos
6.
Clin Cancer Res ; 2(11): 1901-6, 1996 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9816147

RESUMEN

Although considerable experimental evidence suggests an important role of polyamines in breast cancer biology, compelling supportive data in patients are lacking. To address this issue, we measured ornithine decarboxylase (ODC), S-adenosylmethionine decarboxylase, and spermidine/spermine acetyltransferase (the three key polyamine metabolic enzymes) in a cohort of 50 primary human breast cancers and related their levels of activity to disease-free survival and overall survival. The major finding of our study was that ODC activity level was a negative independent prognostic factor for both end points. With regard to overall survival, the adverse influence of ODC expression was superior even to that provided by the number of positive nodes. Furthermore, the statistical significance of the ODC effect on survival was enhanced when breast cancer-specific mortality was included in the analysis as opposed to death from any cause. In addition, high tumor ODC activity may predict a shorter time from recurrence to death, although this effect was of only borderline statistical significance. In summary, these results provide the first concrete evidence supporting the prognostic role of ODC in human breast cancer.


Asunto(s)
Neoplasias de la Mama/enzimología , Ornitina Descarboxilasa/metabolismo , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/mortalidad , Supervivencia sin Enfermedad , Femenino , Humanos , Persona de Mediana Edad , Pronóstico , Análisis de Supervivencia
7.
Clin Cancer Res ; 5(11): 3438-44, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10589756

RESUMEN

DFMO (alpha-difluoromethylornithine) is an oral irreversible inhibitor of ornithine decarboxylase, the first rate-limiting enzyme in polyamine synthesis. DFMO has been shown to have antiproliferative effects against several human cancers, and some studies have suggested that DFMO may have pro-apoptotic and anti-invasive properties as well. DFMO is well tolerated with minimal toxicity but has been associated with ototoxicity with prolonged daily administration. We conducted a Phase I/II tolerability, pharmacokinetic, and efficacy study of high-dose DFMO in metastatic breast cancer patients. Twenty-one patients were treated with 4800 mg of DFMO p.o. three times a day for 14 days, followed by a 2-week drug holiday on a 28-day cycle. Urinary polyamine and blood DFMO levels were measured at multiple time points during therapy. High-dose DFMO was well tolerated, and no clinically significant ototoxicity was noted. No patient achieved an objective antitumor response; however, one patient with heavily pretreated liver metastases has achieved stable disease for 18 months to date on DFMO. Putrescine, spermine, and spermidine urinary levels were suppressed with DFMO treatment and remained low during the 2-week drug holiday. High-dose DFMO on a schedule of 2 weeks on treatment followed by 2 weeks off is well tolerated, is not associated with ototoxicity, and leads to sustained suppression of urinary polyamine levels. Although not an active cytotoxic agent for metastatic breast cancer, the intriguing prolonged growth arrest of liver metastases in one patient highlights the potential clinical growth inhibitory properties of DFMO. We believe that DFMO is worthy of study as adjuvant therapy in primary breast cancer patients and as a chemopreventive agent.


Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Eflornitina/uso terapéutico , Poliaminas/orina , Adulto , Anciano , Antineoplásicos/efectos adversos , Antineoplásicos/farmacocinética , Neoplasias de la Mama/patología , Eflornitina/efectos adversos , Eflornitina/farmacocinética , Femenino , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Putrescina/orina , Receptores de Estrógenos/análisis , Espermidina/orina , Espermina/orina , Factores de Tiempo
8.
Arch Intern Med ; 160(15): 2317-23, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10927729

RESUMEN

BACKGROUND: While lying is morally problematic, physicians have been known to use deception with their patients and with third parties. Little is known, however, about the use of deception between physicians. OBJECTIVES: To determine the likelihood that resident physicians say they would deceive other physicians in various circumstances and to examine how variations in circumstances affect the likelihood of using deception. METHODS: Two versions of a confidential survey using vignettes were randomly distributed to all internal medicine residents at 4 teaching hospitals in 1998. Survey versions differed by introducing slight variations to each vignette in ways we hypothesized would influence respondents' willingness to deceive. The likelihood that residents say they would use deception in response to each vignette was compared between versions. RESULTS: Three hundred thirty surveys were distributed (response rate, 67%). Of those who responded, 36% indicated they were likely to use deception to avoid exchanging call, 15% would misrepresent a diagnosis in a medical record to protect patient privacy, 14% would fabricate a laboratory value to an attending physician, 6% would substitute their own urine in a drug test to protect a colleague, and 5% would lie about checking a patient's stool for blood to cover up a medical mistake. For some of the scenarios, the likelihood of deceiving was influenced by variations in the vignettes. CONCLUSIONS: A substantial percentage of internal medicine residents report they would deceive a colleague in various circumstances, and the likelihood of using deception depends on the context. While lying about clinical issues is not common, it is troubling when it occurs at any time. Medical educators should be aware of circumstances in which residents are likely to deceive, and discuss ways to eliminate incentives to lie.


Asunto(s)
Decepción , Medicina Interna/educación , Internado y Residencia , Relaciones Interprofesionales , Adulto , Competencia Clínica , Recolección de Datos , Ética Médica , Femenino , Humanos , Masculino , Principios Morales
9.
Endocrinology ; 136(4): 1603-9, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7895670

RESUMEN

The follicular phase rise in circulating estradiol causes a suppression of GnRH pulse amplitude and an increase in pulse frequency before stimulation of the preovulatory GnRH surge in the ewe. Studies in which samples were collected at 10-min intervals were found unsuitable to determine whether GnRH secretion is exclusively pulsatile at this time or whether estradiol induces additional qualitative changes in the pattern of GnRH secretion that, combined with the quantitative changes, result in generation of the surge. To address these issues, GnRH was measured in pituitary portal blood and LH in peripheral blood collected at 1- and 10-min intervals, respectively, in ewes receiving no estradiol (n = 5), a luteal phase level of circulating estradiol (n = 5), or a peak follicular phase concentration of estradiol (n = 5). The results provide evidence that, in a dose-dependent manner, estradiol induces the secretion of significant amounts of GnRH between pulses and alters the shape of GnRH pulses by reducing the slope of the rising and falling phases of each pulse. These findings lead to the conclusion that during the presurge period in the ewe, estradiol induces qualitative change in the pattern of GnRH release in addition to stimulating GnRH pulse frequency and reducing pulse amplitude.


Asunto(s)
Estradiol/farmacología , Fase Folicular/fisiología , Hormona Liberadora de Gonadotropina/metabolismo , Periodicidad , Animales , Estradiol/administración & dosificación , Femenino , Hormona Liberadora de Gonadotropina/sangre , Hormona Luteinizante/sangre , Hipófisis/irrigación sanguínea , Ovinos
10.
Endocrinology ; 138(1): 424-32, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8977432

RESUMEN

Continuous sampling of hypophyseal portal blood from unrestrained sheep is providing an unprecedented means for measuring and defining the characteristics of the secretory profile of GnRH. With this method, GnRH has been shown to be released in discrete pulses lasting 5-8 min, with the amplitude of some pulses exceeding 50-fold. Although the relationship between these pulses and the accompanying pulses of LH measured in the jugular vein are unambiguous, the relationship of GnRH pulses to the release of FSH has not been well defined due to the longer clearance of FSH. In previous studies we have shown that hypophyseal portal blood, in addition to serving as a source material for hypothalamic secretions, provides a means to define secretory patterns of pituitary hormones. Because of this we hypothesized that the GnRH-FSH secretory relationship would be easier to define in hypophyseal portal than in jugular vein blood before the secretory products are subjected to dispersion and clearance in circulation. To test this possibility, we monitored hormonal patterns in blood collected at 5-min intervals for 6-12 h from the peripheral and hypophyseal portal circulation of six ovariectomized ewes from a previous study. In contrast to the nonpulsatile pattern of FSH in the peripheral blood, 93% of the GnRH pulses were associated with essentially coincident, discrete pulses of FSH in the portal plasma. Of potentially even greater interest, additional episodes of FSH release were clearly discernible between the GnRH-associated pulses of FSH. As concentrations of peripheral plasma FSH did not reach those in hypophyseal portal plasma, the inter-GnRH episodes of FSH secretion could not result from contaminating peripheral blood. In addition to the episodic mode of secretion, substantial amounts of FSH were found between FSH pulses. This basal component of FSH appeared to be the dominant mode of secretion rather than pulses. The results of this study not only confirm that GnRH pulses lead to pulsatile release of FSH, they also suggest that some other mechanism or factor may be controlling the non-GnRH-associated episodes as well as the basal components of FSH secretion.


Asunto(s)
Hormona Folículo Estimulante/metabolismo , Sistemas Neurosecretores/fisiología , Animales , Femenino , Hormona Liberadora de Gonadotropina/metabolismo , Hormona Luteinizante/metabolismo , Hipófisis/metabolismo , Sistema Porta/fisiología , Ovinos
11.
Endocrinology ; 136(12): 5511-9, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7588302

RESUMEN

Estradiol profoundly influences GnRH secretion during the follicular phase of the estrous cycle of the sheep. Estradiol not only regulates the frequency and amplitude of GnRH pulses, but also produces qualitative changes in its pattern of release and induces a sustained GnRH surge during which discrete pulses are not readily evident. In this study, we tested the hypothesis that qualitative changes in GnRH secretion are an integral part of an estradiol-induced change in the mode of operation of the GnRH neurosecretory system that leads to generation of the GnRH surge. This was achieved by the measurement of GnRH in samples of pituitary portal blood collected at 1-min intervals for an 11-h period encompassing the pre- and early surge periods in an artificial follicular phase model. In each of the seven ewes studied, a highly characteristic alteration in the moment to moment pattern of GnRH was observed. This consisted of a progressive change from a strictly episodic pattern of GnRH release to one containing both episodic and nonepisodic components and, after amplification of both components, a period of extremely high values during which individual episodic increases were no longer readily recognizable. Preliminary mathematical modeling of the data suggested that these patterns could be produced by a change in GnRH from a predominantly low to a mixture of low and high amplitude inputs. Similar changes in minute to minute patterns of GnRH secretion were observed during the natural follicular phase. These findings are consistent with the hypothesis that estradiol induces the GnRH surge by altering the mode of neurosecretion, rather than by merely causing quantitative changes in the episodic pattern of release.


Asunto(s)
Estradiol/farmacología , Fase Folicular/metabolismo , Hormona Liberadora de Gonadotropina/metabolismo , Animales , Femenino , Hormona Liberadora de Gonadotropina/sangre , Hormona Luteinizante/metabolismo , Ovinos
12.
Semin Hematol ; 35(1 Suppl 1): 23-7, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9523746

RESUMEN

We analyzed data from 20 children treated for acute or chronic idiopathic (immune) thrombocytopenic purpura (ITP) at a single institution to determine the relationship between dose of intravenous anti-D immune globulin (WinRho SDF; Nabi, Boca Raton, FL), increase in platelet count, and decrease in hemoglobin in the therapy of ITP. Higher doses of anti-D were clearly associated with a greater therapeutic response in the platelet count, with no increase in hemolysis for both acute and chronic ITP. A significant correlation was found between dose and peak increase in platelet count measured in the 14 days following administration. This effect was present for both acute ITP (17 infusions, P = .0001) and chronic ITP (30 infusions, P = .038). Although hemolysis was seen in nearly all infusions, with a median hemoglobin fall of 1.9 g/dL (range, 0 to 4.2), the decrease in hemoglobin was greater than 2.5 for only three infusions, and the largest fall in hemoglobin (4.2) was in a child with an underlying hemolytic anemia. Furthermore, for both acute and chronic ITP there was no relationship between the decrease in hemoglobin and the dose given (P = .22), nor between the increase in platelet count and fall in hemoglobin (P = .27). This analysis supports the use of higher doses of anti-D for the treatment of ITP, and demonstrates the need for a trial of high-dose anti-D (>100 microg/kg) in acute and chronic ITP.


Asunto(s)
Púrpura Trombocitopénica Idiopática/terapia , Globulina Inmune rho(D)/administración & dosificación , Globulina Inmune rho(D)/uso terapéutico , Adolescente , Anemia Hemolítica/inducido químicamente , Niño , Preescolar , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Lactante , Masculino , Recuento de Plaquetas/efectos de los fármacos , Globulina Inmune rho(D)/efectos adversos
13.
Am J Med Genet ; 103(1): 16-23, 2001 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-11562929

RESUMEN

As genetic testing for susceptibility to breast cancer becomes more widespread, alternative methods for educating individuals prior to testing will be needed. Our objective was to compare face-to-face education and counseling by a genetic counselor with education by an interactive computer program, assessing the effects of each on knowledge of breast cancer genetics and intent to undergo genetic testing. We used a randomized, controlled trial. Seventy-two self-referred women with a first-degree relative with breast cancer received outpatient education and counseling at the Clinical Center of the National Institutes of Health (NIH). Twenty-nine received individualized counseling from a genetic counselor (counseling group), 29 received education from an interactive computer program followed by individualized counseling (computer group), and 14 were controls. Both pre- and postintervention assessment of knowledge about breast cancer genetics and intent to undergo genetic testing were measured. The control group participants correctly answered 74% of the knowledge questions; the counselor group, 92%; and the computer group, 96% (P <.0001). Unadjusted mean knowledge scores were significantly higher in the computer group than the counselor group (P =.048), but they were equivalent when adjusted for demographic differences (P = 0.34). Intent to undergo genetic testing was influenced by the interventions: preintervention, a majority in all groups (69%) indicated that they were likely (definitely and most likely) to undergo testing; after either intervention coupled with counseling, only 44% indicated that they were likely to do so (P =.0002; odds ratio = 2.8, 95% CI = 1.7-4.9). We concluded that a computer program can successfully educate patients about breast cancer susceptibility, and, along with genetic counseling, can influence patients' intentions to undergo genetic testing.


Asunto(s)
Neoplasias de la Mama/genética , Tecnología Educacional/métodos , Pruebas Genéticas/psicología , Adulto , Recursos Audiovisuales , Neoplasias de la Mama/diagnóstico , Tamización de Portadores Genéticos , Asesoramiento Genético/psicología , Predisposición Genética a la Enfermedad/genética , Conocimientos, Actitudes y Práctica en Salud , Humanos , Microcomputadores , Persona de Mediana Edad , Mutación
14.
Int J Oncol ; 19(2): 317-23, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11445845

RESUMEN

To elucidate the role of S-adenosylmethionine decarboxylase (SAMDC) in breast cancer biology, we have generated SAMDC overexpressing MCF-7 breast cancer cells. SAMDC overexpression did not alter in a major way growth properties of MCF-7 cells in soft agar, either under basal conditions or in response to estrogen and antiestrogen administration. SAMDC-MCF-7 cells, on the other hand, exhibited a markedly reduced invasive ability in matrigel (p=0.013). Furthermore, they were less tumorigenic in nude mice. The odds for control clones to form tumors were 3.13 (C.1.1.2-8.2, p=0.0184) higher than those for SAMDC clones. The odds ratio were identical in the absence and in the presence of estradiol. In addition, the growth rate of established tumors was slower for SAMDC than for control clones. Overall, our results are consistent with the notion that these phenotypic changes induced by SAMDC overexpression are primarily mediated by suppression of cellular putrescine (and, possibly, spermidine) levels.


Asunto(s)
Adenosilmetionina Descarboxilasa/metabolismo , Neoplasias de la Mama/patología , Adenosilmetionina Descarboxilasa/genética , Agar , Animales , Antineoplásicos/farmacología , Neoplasias de la Mama/enzimología , Neoplasias de la Mama/prevención & control , División Celular/efectos de los fármacos , Colágeno , Proteínas de Unión al ADN/efectos de los fármacos , Proteínas de Unión al ADN/metabolismo , Combinación de Medicamentos , Factor de Crecimiento Epidérmico/farmacología , Estradiol/análogos & derivados , Estradiol/farmacología , Femenino , Fulvestrant , Humanos , Laminina , Ratones , Ratones Desnudos , Invasividad Neoplásica , Trasplante de Neoplasias , Proteoglicanos , Factor de Transcripción STAT3 , Sensibilidad y Especificidad , Tamoxifeno/farmacología , Transactivadores/efectos de los fármacos , Transactivadores/metabolismo , Trasplante Heterólogo , Células Tumorales Cultivadas/efectos de los fármacos , Ensayo de Tumor de Célula Madre
15.
Brain Res Dev Brain Res ; 109(2): 169-77, 1998 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-9729365

RESUMEN

Studies in adult animal models of transient cerebral hypoxia-ischemia (HI) and ischemia suggest that morphologic evidence of neuronal death in some regions such as striatum appears early, while in other regions such as cerebral cortex and CA1 region of hippocampus it is delayed for few days and is referred to as delayed neuronal death (DND). Moreover, in some regions such as CA2/CA3 early 'reactive' neuronal changes occur that are potentially reversible. The aim of this study was to determine whether such changes may also occur in the developing brain. To that end, unilateral cerebral HI was produced in postnatal rats of 13, 21, and 30 days (p13, p21, p30) by right common carotid artery ligation and hypoxemia (breathing 8% O2), and their brains were examined at 24 h, 36 h, 72 h, and 96 h of recovery. The results suggest that: (i) DND is present in developing brain, but its regional distribution varies with animals' age. In cerebral cortex, it is more pronounced in p30 rats than in younger animals. In hippocampus, comparison of lesions of similar severity at different age groups shows a more pronounced DND in CA2/CA3 region of p13 rats than in older animals, but no significant differences exist in the degree of DND in CA1 neurons among different age groups. (ii) 'Reactive' neuronal changes characterized by reduction in Nissl staining and acidophilia of neuronal perikaryon with minimal nuclear abnormality are present at 24 h of recovery. These changes in some regions, such as in CA1 and cortex, progress to neuronal death, while in other regions such as in CA2/CA3 are potentially reversible. (iii) Recovery of reactive neurons in CA2/CA3 region is age dependent in that there is significant recovery in the older age groups, but not in p13 rats. The pathogenetic mechanisms of the reactive neuronal changes, the chain of events leading to DND or neuronal recovery, and the influence of age in these processes remain to be elucidated.


Asunto(s)
Encéfalo/crecimiento & desarrollo , Encéfalo/patología , Hipoxia Encefálica/patología , Ataque Isquémico Transitorio/patología , Neuronas/patología , Animales , Recuento de Células , Muerte Celular/fisiología , Corteza Cerebral/patología , Femenino , Hipocampo/patología , Embarazo , Ratas , Ratas Wistar
16.
Brain Res Dev Brain Res ; 100(2): 149-60, 1997 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-9205806

RESUMEN

The most frequently used model of neonatal cerebral hypoxia-ischemia consists of a 7-day postnatal rat model with combined common carotid artery ligation and hypoxemia. Neuropathologic studies have shown major differences between this 7-day postnatal rat model and a similar adult model in regard to overall cerebral vulnerability, type and distribution of lesions. It is not clear how and when during animals' development these changes in cerebral vulnerability take place. To determine this we studied groups of rats of 2 to 30 postnatal days. The animals underwent unilateral common carotid artery ligation followed by breathing in 8% oxygen for 30, 60, 90, or 120 min and their brains were examined at 24- or 72-h recovery intervals. Due to resistance of 2-3-day-old rats to develop cerebral hypoxic-ischemic damage, 5% O2 was used instead of 8% O2. The results indicate that: (i) There is an overall increase in severity of cerebral lesions on the side of common carotid artery ligation between 2 and 7 postnatal days. There is also an increase in the frequency of cerebral lesions in developing animals with increasing age. (ii) Hippocampus is remarkably resistant to hypoxic-ischemic insult at 2-3 postnatal days but becomes progressively vulnerable, and by age 13 postnatal days hippocampal vulnerability far exceeds that of cortex. (iii) Cortical lesions change from predominantly columnar cell death to laminar selective neuronal death at age 13 postnatal days. (iv) Also significant changes occur in relative vulnerability of various hippocampal regions during development. During the first 5 postnatal days relative vulnerability of hippocampal regions is similar, but as the animals' development proceeds and hippocampal vulnerability increases lesions tend to involve specific regions while sparing others. By age 13 postnatal days CA1 and lateral CA3 develop increased vulnerability while medial CA3 and fascia dentata become relatively resistant and by 21 postnatal days adult pattern of CA1 selective vulnerability is approached. The underlying mechanisms for these changes in regional vulnerability to cerebral hypoxia-ischemia during development should be sought in complex regional anatomic, functional, and metabolic alterations that take place as brain matures.


Asunto(s)
Envejecimiento/fisiología , Isquemia Encefálica/patología , Encéfalo/crecimiento & desarrollo , Encéfalo/patología , Hipoxia Encefálica/patología , Animales , Femenino , Hipocampo/crecimiento & desarrollo , Hipocampo/patología , Neuronas/efectos de los fármacos , Neuronas/fisiología , Embarazo , Ratas , Ratas Wistar
17.
Brain Res Dev Brain Res ; 113(1-2): 83-95, 1999 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-10064878

RESUMEN

The present investigation was designed to study the effect of chemically induced seizures on cerebral hypoxic-ischemic (HI) damage in immature animals. Accordingly, cerebral HI was produced in 7-day postnatal (p7) rats and p13 rats by combined unilateral common carotid artery ligation and hypoxia with 8% oxygen. Seizures were induced chemically by the subcutaneous injection of kainic acid (KA) or inhalation of flurothyl vapor. Three types of experiments were conducted in each age group and for each convulsant. In some animals (group 1), seizures were produced at 24 h and again at 6 h prior to HI. In groups 2 and 3, seizures were induced 2 h or 24 h post HI, respectively. The results indicate that in group 1 animals, the first seizure significantly reduced duration of the second seizure challenge 18 h later at both p7 and p13 (p=0.001). Histologic examination of brains of animals in group 1 subjected to seizures prior to HI and their HI-only controls showed that seizures prior to HI conferred protection against cerebral damage. This effect was significant for flurothyl seizures in p13 rats for all cerebral regions, especially hippocampal CA1 (p=0.0004), and in p7 rats for hippocampus (p=0.04) and particularly cerebral cortex (p=0.007). For KA seizures, the protective effect was only significant in p13 rats and was limited to hippocampal CA regions and subiculum (p=0.0009). Histologic assessment of cerebral lesions of p7 and p13 rats in the other two groups showed no significant difference between the animals subjected to seizures 2 h or 24 h post HI and their HI-only controls (p>0.05). In conclusion, the results of the present study provide no evidence that seizures in early postnatal development aggravate pre-existing cerebral HI damage. They do suggest that seizures prior to HI or prior to a second seizure confer tolerance to both conditions.


Asunto(s)
Isquemia Encefálica/fisiopatología , Epilepsia/fisiopatología , Hipocampo/irrigación sanguínea , Hipocampo/crecimiento & desarrollo , Hipoxia Encefálica/fisiopatología , Animales , Animales Recién Nacidos , Conducta Animal/fisiología , Convulsivantes , Epilepsia/inducido químicamente , Agonistas de Aminoácidos Excitadores , Femenino , Flurotilo , Hipocampo/fisiopatología , Ácido Kaínico , Embarazo , Ratas , Ratas Wistar
18.
Fertil Steril ; 72(1): 21-5, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10428143

RESUMEN

OBJECTIVE: To examine bone mineral density (BMD) and fat distribution in lean women with polycystic ovary syndrome (PCOS) compared with matched control women. DESIGN: Controlled clinical study. SETTING: An academic clinical research center. PATIENT(S): Twelve non-Hispanic white women with PCOS and a body mass index of <26 and 10 healthy control women matched for age, ethnicity, and weight. INTERVENTION(S): Biometric measures, blood sample collection, and total body/regional bone density and fat analysis were performed. MAIN OUTCOME MEASURE(S): Serum levels of androgens, glucose, and insulin were measured. Bone density and fat distribution were measured by total body dual-energy x-ray absorptiometry. RESULT(S): Androgen levels were elevated significantly in the lean women with PCOS compared with the controls. There was no statistically significant difference in total body BMD between the two groups. A significant increase in BMD was noted in the left arm, right arm, and left ribs of the lean PCOS group. Evaluation of upper body BMD showed a significant correlation between testosterone levels and BMD. No statistically significant differences were noted in body fat distribution, although the lean PCOS group tended to have lower mean percentages of body fat. CONCLUSION(S): Lean women with PCOS have regional differences in BMD, with significantly increased BMD in the upper skeleton compared with control women.


Asunto(s)
Composición Corporal , Densidad Ósea , Síndrome del Ovario Poliquístico/fisiopatología , Absorciometría de Fotón , Tejido Adiposo/fisiología , Adulto , Constitución Corporal , Índice de Masa Corporal , Femenino , Humanos
19.
Acad Radiol ; 7(9): 693-9, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10987330

RESUMEN

RATIONALE AND OBJECTIVES: The purpose of this study was to assess resident scores on the American College of Radiology (ACR) In-Training Examination and on the written American Board of Radiology (ABR) Examination relative to attendance at and timing of the Armed Forces Institute of Pathology (AFIP) Radiologic Pathology Course. MATERIALS AND METHODS: A survey of 200 radiology residency program directors requested the type of residency program, whether the program sent residents to the AFIP course, dates of AFIP attendance for individual residents, percentile scores of residents on the ACR examination from 1995 through 1998, and ABR examination scores for 1997. Scores were analyzed before and after AFIP attendance and also temporally for examinations during or after AFIP attendance. Improvement in percentile scores for residents undergoing the ACR examination while attending the AFIP were compared with scores of matched residents from their programs who had not attended. RESULTS: Thirty-six (18%) program directors responded, providing data on 619 residents who underwent the ACR examination, ABR examination, or both. No significant improvement was found between pre- and post-AFIP ACR Examination scores for residents at university or military programs. There were statistically significantly improved scores for residents at community programs (mean percentile improvement, 8.1 points; P = .0064). Residents who underwent the ACR examination during the AFIP course improved their scores by 10.7 percentile points compared with matched residents who had not attended the AFIP course (P = .041). CONCLUSION: Residents undergoing the ACR examination while attending the AFIP improve their percentile scores more than residents who have not attended the AFIP.


Asunto(s)
Curriculum , Evaluación Educacional , Internado y Residencia , Patología Clínica/educación , Radiología/educación , Recolección de Datos/métodos , Humanos , Medicina Militar
20.
Acad Radiol ; 6(1): 66-71, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9891155

RESUMEN

RATIONALE AND OBJECTIVES: The authors assessed the ability of faculty and residents to predict the ranked performance of residents on the American College of Radiology (ACR) In-Training Examination. MATERIALS AND METHODS: Radiology faculty at Penn State Geisinger Health System (PSGHS), the Medical College of Virginia (MCV), and the University of Virginia (UVA) and residents at PSGHS and MCV ranked the expected performances of residents taking the 1997 ACR In-Training Examination. Surveyed faculty and residents were blinded to the actual performances on the examination. Forty-nine residents took the examination (21 at PSGHS, 22 at MCV, six at UVA), and 37 faculty members (11 at PSGHS, 11 at MCV, 15 at UVA) participated in the study. Correlation analysis was performed to assess the agreement between the subjective and actual ranking of residents in each residency class. RESULTS: Faculty were moderately accurate in the overall ranking of resident performances (r = 0.34). High levels of concordance for ranking individual residents correlated with accuracy in only certain cases. Differences in agreement and accuracy of the respondents existed between PSGHS and MCV (P = .0001 and .0014, respectively). The concordance of respondents increased significantly from the 1st- to the 2nd-year class at MCV (P = .0002), whereas accuracy increased significantly between these classes for the PSGHS (P = .042). CONCLUSION: Faculty are only moderately successful in ranking resident performances on the ACR In-Training Examination, and a high level of agreement is not necessarily indicative of increased accuracy. The concordance and accuracy of subjective rankings differ among residency programs and classes.


Asunto(s)
Competencia Clínica , Evaluación Educacional/métodos , Internado y Residencia , Radiología/educación , Docentes Médicos , Retroalimentación , Femenino , Predicción , Humanos , Relaciones Interprofesionales , Masculino , Reproducibilidad de los Resultados
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