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1.
Int J Tuberc Lung Dis ; 28(9): 419-426, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-39187999

RESUMEN

OBJECTIVESPulmonary TB (PTB) increases the risk of chronic lung complications, which are associated with increased morbidity and mortality. We determined the prevalence and predictors of post-TB lung disease and persistent symptoms in a resource-limited setting.METHODSAdults who completed PTB treatment underwent spirometry and completed the St. George's Respiratory Questionnaire (SGRQ), a questionnaire that assesses quality of life on symptom, activity, and impact. We performed multivariate analyses to calculate the X-adjusted prevalence ratio (PRadj) of abnormal spirometry and identify associated risk factors.RESULTSAmong the 162 participants, 89 (54.9%) were male. The median age was 32 years, and 65 (40.1%) had HIV. Overall, 65 participants (40.1%) had abnormal lung function, with spirometric restriction seen in 29.0%, obstruction in 4.9%, and a mixed pattern in 6.2%. Smoking (PRadj 1.88, 95% CI 1.11-3.16; P = 0.02) and female sex (PRadj 1.81, 95% Cl 1.15-2.84; P = 0.01) were independent risk factors for abnormal lung function. The median SGRQ scores were higher in participants with cavitation (P < 0.001) or bilateral consolidation on initial chest X-ray (P = 0.01).CONCLUSIONSLung function abnormalities, particularly spirometric restriction, are common in patients completing PTB treatment. Female sex and smoking status were associated with lung function abnormalities; therefore, additional studies to understand the underlying mechanistic pathways are warranted..


Asunto(s)
Calidad de Vida , Espirometría , Tuberculosis Pulmonar , Humanos , Masculino , Femenino , Adulto , Tuberculosis Pulmonar/tratamiento farmacológico , Factores de Riesgo , Encuestas y Cuestionarios , Prevalencia , Adulto Joven , Pulmón/fisiopatología , Persona de Mediana Edad , Antituberculosos/administración & dosificación , Fumar/epidemiología , Estudios Transversales , Análisis Multivariante
3.
BMC Geriatr ; 21(1): 415, 2021 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-34229623

RESUMEN

BACKGROUND: Older age and comorbid burden are both associated with adverse outcomes in SARS-CoV-2, but it is not known whether the association between comorbid burden and adverse outcomes differs in older and younger adults. OBJECTIVE: To compare the relationship between comorbid burden and adverse outcomes in adults with SARS-CoV-2 of different ages (18-64, 65-79 and ≥ 80 years). DESIGN, SETTING, AND PARTICIPANTS: Observational longitudinal cohort study of 170,528 patients who tested positive for SARS-CoV-2 in the US Department of Veterans Affairs (VA) Health Care System between 2/28/20 and 12/31/2020 who were followed through 01/31/2021. MEASUREMENTS: Charlson Comorbidity Index (CCI); Incidence of hospitalization, intensive care unit (ICU) admission, mechanical ventilation, and death within 30 days of a positive SARS-CoV-2 test. RESULTS: The cumulative 30-day incidence of death was 0.8% in cohort members < 65 years, 7.1% in those aged 65-79 years and 20.6% in those aged ≥80 years. The respective 30-day incidences of hospitalization were 8.2, 21.7 and 29.5%, of ICU admission were 2.7, 8.6, and 11% and of mechanical ventilation were 1, 3.9 and 3.2%. Median CCI (interquartile range) ranged from 0.0 (0.0, 2.0) in the youngest, to 4 (2.0, 7.0) in the oldest age group. The adjusted association of CCI with all outcomes was attenuated at older ages such that the threshold level of CCI above which the risk for each outcome exceeded the reference group (1st quartile) was lower in younger than in older cohort members (p < 0.001 for all age group interactions). LIMITATIONS: The CCI is calculated based on diagnostic codes, which may not provide an accurate assessment of comorbid burden. CONCLUSIONS: Age differences in the distribution and prognostic significance of overall comorbid burden could inform clinical management, vaccination prioritization and population health during the pandemic and argue for more work to understand the role of age and comorbidity in shaping the care of hospitalized patients with SARS-CoV-2.


Asunto(s)
COVID-19 , SARS-CoV-2 , Anciano , Hospitalización , Humanos , Unidades de Cuidados Intensivos , Estudios Longitudinales , Persona de Mediana Edad , Pandemias
4.
HIV Med ; 22(2): 92-101, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33022830

RESUMEN

OBJECTIVES: The relationship between marijuana use and markers of chronic lung disease in people living with HIV (PLWH) is poorly understood. METHODS: We performed a cross-sectional analysis of the Examinations of HIV-Associated Lung Emphysema (EXHALE) study, including 162 HIV-positive patients and 138 participants without HIV. We modelled marijuana exposure as: (i) current daily or weekly marijuana smoking vs. monthly or less often; or (ii) cumulative marijuana smoking (joint-years). Linear and logistic regression estimated associations between marijuana exposure and markers of lung disease, adjusted for tobacco smoking and other factors. RESULTS: In PLWH, current daily or weekly marijuana use was associated with a larger forced vital capacity (FVC), larger total lung capacity and increased odds of radiographic emphysema compared with marijuana non-smokers in adjusted models; these associations were not statistically significant in participants without HIV. Marijuana joint-years were associated with higher forced expiratory volume in 1 s and FVC in PLWH but not with emphysema. CONCLUSIONS: In PLWH, marijuana smoking was associated with higher lung volumes and potentially with radiographic emphysema. No consistently negative associations were observed between marijuana and measures of chronic lung health.


Asunto(s)
Cannabis , Infecciones por VIH , Enfermedades Pulmonares , Estudios Transversales , Infecciones por VIH/complicaciones , Humanos , Enfermedades Pulmonares/diagnóstico por imagen , Capacidad Vital
5.
Am J Physiol Lung Cell Mol Physiol ; 316(2): L400-L405, 2019 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-30520689

RESUMEN

Cigarette smoke exposure is the leading modifiable risk factor for chronic obstructive pulmonary disease (COPD); however, the clinical and pathologic consequences of chronic cigarette smoke exposure are variable among smokers. Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine implicated in the pathogenesis of COPD. Within the promoter of the MIF gene is a functional polymorphism that regulates MIF expression (-794 CATT5-8 microsatellite repeat) ( rs5844572 ). The role of this polymorphim in mediating disease susceptibility to COPD-related traits remains unknown. We performed a cross-sectional analysis of DNA samples from 641 subjects to analyze MIF-794 CATT5-8 ( rs5844572 ) polymorphism by standard methods. We generated multivariable logistic regression models to determine the risk of low expressing MIF alleles for airflow obstruction [defined by forced expiratory volume in 1 s (FEV1)/forced vital capacity ratio <0.70] and an abnormal diffusion capacity [defined by a diffusion capacity for carbon monoxide (DLCO) percent predicted <80%]. We then used generalized linear models to determine the association of MIF genotypes with FEV1 percent predicted and DLCO percent predicted. The MIF-794 CATT5 allele was associated with an abnormal diffusion capacity in two cohorts [odds ratio (OR): 9.31, 95% confidence interval (CI): 1.97-4.06; and OR: 2.21, 95% CI: 1.03-4.75]. Similarly, the MIF-794 CATT5 allele was associated with a reduced DLCO percentage predicted in these two cohorts: 63.5 vs. 70.0 ( P = 0.0023) and 60.1 vs. 65.4 ( P = 0.059). This study suggests an association between a common genetic polymorphism of an endogenous innate immune gene, MIF, with reduced DLCO, an important measurement of COPD severity.


Asunto(s)
Factores Inhibidores de la Migración de Macrófagos/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/genética , Humo/efectos adversos , Capacidad Vital/genética , Volumen Espiratorio Forzado/genética , Predisposición Genética a la Enfermedad/genética , Pulmón/metabolismo , Factores Inhibidores de la Migración de Macrófagos/genética , Polimorfismo de Nucleótido Simple/genética , Regiones Promotoras Genéticas/genética , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Pruebas de Función Respiratoria , Capacidad Vital/fisiología
6.
HIV Med ; 17(10): 728-739, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27186715

RESUMEN

OBJECTIVES: Certain prescribed opioids have immunosuppressive properties, yet their impact on clinically relevant outcomes, including antiretroviral therapy (ART) response among HIV-infected patients, remains understudied. METHODS: Using the Veterans Aging Cohort Study data, we conducted a longitudinal analysis of 4358 HIV-infected patients initiating ART between 2002 and 2010 and then followed them for 24 months. The primary independent variable was prescribed opioid duration, categorized using pharmacy data as none prescribed, short-term (< 90 days) and long-term (≥ 90 days). Outcomes included CD4 cell count over time. Analyses adjusted for demographics, comorbid conditions, ART type and year of initiation, and overall disease severity [ascertained with the Veterans Aging Cohort Study (VACS) Index]. Sensitivity analyses examined whether effects varied according to baseline CD4 cell count, achievement of viral load suppression, and opioid properties (i.e. dose and known immunosuppressive properties). RESULTS: Compared to those with none, patients with short-term opioids had a similar increase in CD4 cell count (mean rise per year: 74 vs. 68 cells/µL; P = 0.11), as did those with long-term prescribed opioids (mean rise per year: 74 vs. 75 cells/µL; P = 0.98). In sensitivity analysis, compared with no opioids, the effects of short-term prescribed opioids were statistically significant among those with a baseline CD4 cell count ≥ 500 cells/µL (mean rise per year: 52 cells/µL for no opioids vs. 20 cells/µL for short-term opioids; P = 0.04); findings were otherwise unchanged. CONCLUSIONS: Despite immunosuppressive properties intrinsic to opioids, prescribed opioids appeared to have no effect on CD4 cell counts over 24 months among HIV-infected patients initiating ART.


Asunto(s)
Analgésicos Opioides/efectos adversos , Analgésicos Opioides/uso terapéutico , Antirretrovirales/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/patología , Inmunosupresores/efectos adversos , Inmunosupresores/uso terapéutico , Adulto , Recuento de Linfocito CD4 , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad
7.
Curr HIV/AIDS Rep ; 13(3): 140-8, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27121734

RESUMEN

Pulmonary complications remain among the most frequent causes of morbidity and mortality for individuals with HIV despite the advent of antiretroviral therapy (ART) and improvement in its efficacy and availability. The prevalence of non-infectious pulmonary diseases is rising in this population, reflecting both an increase in smoking and the independent risk associated with HIV. The unique mechanisms of pulmonary disease in these patients remain poorly understood, and direct effects of HIV, genetic predisposition, inflammatory pathways, and co-infections have all been implicated. Lung cancer, chronic obstructive pulmonary disease (COPD), and pulmonary hypertension are the most prevalent non-infectious pulmonary diseases in persons with HIV, and the risk of each of these diseases is higher among HIV-infected (HIV+) persons than in the general population. This review discusses the latest advances in the literature on these important complications of HIV infection.


Asunto(s)
Infecciones por VIH/complicaciones , Hipertensión Pulmonar/complicaciones , Neoplasias Pulmonares/complicaciones , Pulmón/fisiopatología , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Fármacos Anti-VIH/uso terapéutico , Coinfección , Predisposición Genética a la Enfermedad , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/inmunología , Infecciones por VIH/fisiopatología , Humanos , Hipertensión Pulmonar/genética , Hipertensión Pulmonar/inmunología , Hipertensión Pulmonar/fisiopatología , Pulmón/virología , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/fisiopatología , Prevalencia , Enfermedad Pulmonar Obstructiva Crónica/genética , Enfermedad Pulmonar Obstructiva Crónica/inmunología , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Factores de Riesgo , Fumar/efectos adversos
8.
HIV Med ; 16(7): 421-30, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25959543

RESUMEN

OBJECTIVES: Outcomes of community-acquired pneumonia (CAP) among HIV-infected older adults are unclear. METHODS: Associations between HIV infection and three CAP outcomes (30-day mortality, readmission within 30 days post-discharge, and hospital length of stay [LOS]) were examined in the Veterans Aging Cohort Study (VACS) of male Veterans, age ≥ 50 years, hospitalized for CAP from 10/1/2002 through 08/31/2010. Associations between the VACS Index and CAP outcomes were assessed in multivariable models. RESULTS: Among 117 557 Veterans (36 922 HIV-infected and 80 635 uninfected), 1203 met our eligibility criteria. The 30-day mortality rate was 5.3%, the mean LOS was 7.3 days, and 13.2% were readmitted within 30 days of discharge. In unadjusted analyses, there were no significant differences between HIV-infected and uninfected participants regarding the three CAP outcomes (P > 0.2). A higher VACS Index was associated with increased 30-day mortality, readmission, and LOS in both HIV-infected and uninfected groups. Generic organ system components of the VACS Index were associated with adverse CAP outcomes; HIV-specific components were not. Among HIV-infected participants, those not on antiretroviral therapy (ART) had a higher 30-day mortality (HR 2.94 [95% CI 1.51, 5.72]; P = 0.002) and a longer LOS (slope 2.69 days [95% CI 0.65, 4.73]; P = 0.008), after accounting for VACS Index. Readmission was not associated with ART use (OR 1.12 [95% CI 0.62, 2.00] P = 0.714). CONCLUSION: Among HIV-infected and uninfected older adults hospitalized for CAP, organ system components of the VACS Index were associated with adverse CAP outcomes. Among HIV-infected individuals, ART was associated with decreased 30-day mortality and LOS.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/mortalidad , Infecciones Comunitarias Adquiridas/mortalidad , Infecciones por VIH/mortalidad , Readmisión del Paciente/estadística & datos numéricos , Neumonía/mortalidad , Veteranos/estadística & datos numéricos , Infecciones Oportunistas Relacionadas con el SIDA/inmunología , Biomarcadores , Infecciones Comunitarias Adquiridas/inmunología , Infecciones por VIH/complicaciones , Infecciones por VIH/inmunología , Humanos , Tiempo de Internación/estadística & datos numéricos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Neumonía/etiología , Neumonía/inmunología , Análisis de Supervivencia , Estados Unidos/epidemiología
9.
HIV Med ; 16(2): 105-13, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25230851

RESUMEN

OBJECTIVES: In HIV-uninfected populations, obstructive sleep apnoea (OSA) is commonly associated with cardiovascular disease, metabolic syndrome, and cognitive impairment. These comorbidities are common in HIV-infected patients, but there are scarce data regarding OSA in HIV-infected patients. Therefore, we examined the prevalence and correlates of OSA in a cohort of HIV-infected and uninfected patients. METHODS: An observational cohort study was carried out. Electronic medical record and self-report data were examined in patients enrolled in the Veterans Aging Cohort Study (VACS) between 2002 and 2008 and followed until 2010. The primary outcome was OSA diagnosis, determined using International Classification of Diseases, 9th edition (ICD-9) codes, in HIV-infected compared with uninfected individuals. We used regression analyses to determine the association between OSA diagnosis, symptoms and comorbidities in adjusted models. RESULTS: Of 3683 HIV-infected and 3641 uninfected patients, 143 (3.9%) and 453 (12.4%) had a diagnosis of OSA (p<0.0001), respectively. HIV-infected patients were more likely to report symptoms associated with OSA such as tiredness and fatigue. Compared with uninfected patients with OSA, HIV-infected patients with OSA were younger, had lower body mass indexes (BMIs), and were less likely to have hypertension. In models adjusting for these traditional OSA risk factors, HIV infection was associated with markedly reduced odds of OSA diagnosis (odds ratio 0.48; 95% confidence interval 0.39-0.60). CONCLUSIONS: HIV-infected patients are less likely to receive a diagnosis of OSA. Future studies are needed to determine whether the lower prevalence of OSA diagnoses in HIV-infected patients is attributable to decreased screening and detection or to a truly decreased likelihood of OSA in the setting of HIV infection.


Asunto(s)
Infecciones por VIH/epidemiología , Obesidad/epidemiología , Polisomnografía , Respiración con Presión Positiva , Apnea Obstructiva del Sueño/epidemiología , Veteranos , Factores de Edad , Índice de Masa Corporal , Estudios de Cohortes , Comorbilidad , Femenino , Infecciones por VIH/complicaciones , Infecciones por VIH/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Obesidad/complicaciones , Obesidad/fisiopatología , Oportunidad Relativa , Prevalencia , Factores de Riesgo , Factores Sexuales , Apnea Obstructiva del Sueño/etiología , Apnea Obstructiva del Sueño/fisiopatología , Encuestas y Cuestionarios , Estados Unidos/epidemiología
10.
Epidemiol Infect ; 142(7): 1459-66, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24067406

RESUMEN

The impact of hepatitis C virus infection (HCI), the most common bloodborne virus infection in the USA, on outcome of active tuberculosis (TB) treatment is largely unknown. We aimed to describe characteristics of TB patients with hepatitis C virus infection (TB-HCI) in King County, Washington, including TB treatment duration and outcome. We reviewed 1510 records of patients treated for active TB at the Public Health - Seattle & King County Tuberculosis Control Program between 2000 and 2010, and identified 53 with HCI. Advanced age, being born in the USA, HIV infection, homelessness and injection drug use were independently associated with HCI in TB cases. Independent factors associated with increased treatment duration included HIV infection, excess alcohol use, extrapulmonary TB, and any drug-resistant TB disease. Our findings suggest that TB-HCI patients can be successfully treated for active TB without extending treatment duration.


Asunto(s)
Coinfección/epidemiología , Hepatitis C/epidemiología , Hepatitis C/microbiología , Tuberculosis/epidemiología , Tuberculosis/virología , Adulto , Antituberculosos/efectos adversos , Antituberculosos/uso terapéutico , Coinfección/microbiología , Coinfección/virología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Resultado del Tratamiento , Tuberculosis/tratamiento farmacológico , Washingtón/epidemiología
11.
Br J Cancer ; 109(7): 1974-80, 2013 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-24022194

RESUMEN

BACKGROUND: We conducted a population-based study to evaluate whether non-small cell lung cancer (NSCLC) prognosis was worse in HIV-infected compared with HIV-uninfected patients. METHODS: Using the Surveillance, Epidemiology and End Results (SEER) registry linked to Medicare claims, we identified 267 HIV-infected patients and 1428 similar controls with no evidence of HIV diagnosed with NSCLC between 1996 and 2007. We used conditional probability function (CPF) analyses to compare survival by HIV status accounting for an increased risk of non-lung cancer death (competing risks) in HIV-infected patients. We used multivariable CPF regression to evaluate lung cancer prognosis by HIV status adjusted for confounders. RESULTS: Stage at presentation and use of stage-appropriate lung cancer treatment did not differ by HIV status. Median survival was 6 months (95% confidence interval (CI): 5-8 months) among HIV-infected NSCLC patients compared with 20 months (95% CI: 17-23 months) in patients without evidence of HIV. Multivariable CPF regression showed that HIV was associated with a greater risk of lung cancer-specific death after controlling for confounders and competing risks. CONCLUSION: NSCLC patients with HIV have a poorer prognosis than patients without evidence of HIV. NSCLC may exhibit more aggressive behaviour in the setting of HIV.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/complicaciones , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Infecciones por VIH/complicaciones , Infecciones por VIH/mortalidad , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/mortalidad , Anciano , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/patología , Femenino , Infecciones por VIH/diagnóstico , Humanos , Pulmón/patología , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Pronóstico , Programa de VERF , Tasa de Supervivencia , Estados Unidos
12.
Thorax ; 63(4): 329-34, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18024536

RESUMEN

BACKGROUND: When Pneumocystis DNA is recovered from respiratory specimens of patients without Pneumocystis pneumonia (PCP), patients are said to be colonised with Pneumocystis, although the significance of this state is unknown. Understanding risk factors for and outcomes of colonisation may provide insights into the life cycle and transmission dynamics of Pneumocystis jirovecii. METHODS: We performed a cross sectional study of the prevalence and clinical predictors of Pneumocystis colonisation in 172 HIV infected, PCP negative inpatients undergoing diagnostic evaluation of 183 episodes of pneumonia at either the Medical Center of Louisiana at New Orleans between 2003 and 2005 or San Francisco General Hospital between 2000 and 2005. DNA was extracted from sputum and bronchoalveolar lavage specimens and amplified using a nested PCR assay at the mitochondrial large subunit (18S) ribosomal RNA locus. Colonisation was deemed present if Pneumocystis DNA was identified by both gel electrophoresis and direct DNA sequencing. RESULTS: 68% (117/172) of all patients were colonised with Pneumocystis. No strong associations with colonisation were identified for any demographic factors. Among clinical factors, having a CD4+ T cell count

Asunto(s)
Linfocitos T CD4-Positivos , Infecciones por VIH/microbiología , Pneumocystis carinii/aislamiento & purificación , Neumonía por Pneumocystis/microbiología , Adulto , Anciano , Recuento de Linfocito CD4 , Estudios Transversales , Femenino , Hospitalización , Humanos , Masculino , Persona de Mediana Edad
13.
HIV Med ; 4(4): 346-9, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14525547

RESUMEN

Although several studies have reported that it is safe to discontinue secondary Pneumocystis carinii pneumonia (PCP) prophylaxis in patients infected with HIV who experience a sustained immune response as a result of antiretroviral therapy, we describe a patient who developed recurrent PCP <3 months after discontinuing trimethoprim-sulfamethoxazole prophylaxis. He developed disease despite a sustained CD4 T-cell count above 200 cells/microL for more than 3 years while on antiretroviral therapy, as well as an apparent immune reconstitution against disseminated Mycobacterium avium complex (MAC) and Histoplasma capsulatum, for which he also discontinued therapy but without adverse effects. Thus, although increasing evidence continues to indicate that HIV-infected patients receiving combinations of antiretroviral therapies may regain specific immunity against opportunistic infections, our patient's experience suggests that this immune recovery may be selective and incomplete.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/complicaciones , Antiinfecciosos/uso terapéutico , Terapia Antirretroviral Altamente Activa , Neumonía por Pneumocystis/complicaciones , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Infecciones Oportunistas Relacionadas con el SIDA/inmunología , Adulto , Recuento de Linfocito CD4 , Humanos , Masculino , Neumonía por Pneumocystis/tratamiento farmacológico , Neumonía por Pneumocystis/inmunología , Prevención Secundaria , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
15.
J Biol Chem ; 272(29): 18132-9, 1997 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-9218447

RESUMEN

Insulin-like growth factor-I (IGF-I) is a key factor in bone remodeling. In osteoblasts, IGF-I synthesis is enhanced by parathyroid hormone and prostaglandin E2 (PGE2) through cAMP-activated protein kinase. In rats, estrogen loss after ovariectomy leads to a rise in serum IGF-I and an increase in bone remodeling, both of which are reversed by estrogen treatment. To examine estrogen-dependent regulation of IGF-I expression at the molecular level, primary fetal rat osteoblasts were co-transfected with the estrogen receptor (hER, to ensure active ER expression), and luciferase reporter plasmids controlled by promoter 1 of the rat IGF-I gene (IGF-I P1), used exclusively in these cells. As reported, 1 microM PGE2 increased IGF-I P1 activity by 5-fold. 17beta-Estradiol alone had no effect, but dose-dependently suppressed the stimulatory effect of PGE2 by up to 90% (ED50 approximately 0.1 nM). This occurred within 3 h, persisted for at least 16 h, required ER, and appeared specific, since 17alpha-estradiol was 100-300-fold less effective. By contrast, 17beta-estradiol stimulated estrogen response element (ERE)-dependent reporter expression by up to 10-fold. 17beta-Estradiol also suppressed an IGF-I P1 construct retaining only minimal promoter sequence required for cAMP-dependent gene activation, but did not affect the 60-fold increase in cAMP induced by PGE2. There is no consensus ERE in rat IGF-I P1, suggesting novel downstream interactions in the cAMP pathway that normally enhances IGF-I expression in skeletal cells. To explore this, nuclear extract from osteoblasts expressing hER were examined by electrophoretic mobility shift assay using the atypical cAMP response element in IGF-I P1. Estrogen alone did not cause DNA-protein binding, while PGE2 induced a characteristic gel shift complex. Co-treatment with both hormones caused a gel shift greatly diminished in intensity, consistent with their combined effects on IGF-I promoter activity. Nonetheless, hER did not bind IGF-I cAMP response element or any adjacent sequences. These results provide new molecular evidence that estrogen may temper the biological effects of hormones acting through cAMP to regulate skeletal IGF-I expression and activity.


Asunto(s)
AMP Cíclico/fisiología , Dinoprostona/farmacología , Estradiol/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Factor I del Crecimiento Similar a la Insulina/biosíntesis , Osteoblastos/metabolismo , Receptores de Estrógenos/fisiología , Animales , Sitios de Unión , Diferenciación Celular , Núcleo Celular/metabolismo , Células Cultivadas , Secuencia de Consenso , AMP Cíclico/antagonistas & inhibidores , Proteínas de Unión al ADN/biosíntesis , Proteínas de Unión al ADN/fisiología , Feto , Genes Reporteros , Humanos , Factor I del Crecimiento Similar a la Insulina/genética , Cinética , Luciferasas/biosíntesis , Osteoblastos/citología , Osteoblastos/efectos de los fármacos , Regiones Promotoras Genéticas , Ratas , Ratas Sprague-Dawley , Receptores de Estrógenos/biosíntesis , Receptores de Estrógenos/efectos de los fármacos , Proteínas Recombinantes de Fusión/biosíntesis , Activación Transcripcional , Transfección
16.
J Med Educ ; 54(12): 932-7, 1979 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-513095

RESUMEN

In this article the authors describe the contribution to health science teaching made by volunteer patients in a purely educational setting. Patients with documented illnesses volunteer to give their own history, to be examined, and frequently to provide feedback to students. The over 2,500 such volunteer patients who have participated in this program in a six-year period are enthusiastic and highly motivated. Significant educational benefits are achieved, including the assumption of teaching responsibilities by nonprofessionals. The fact that this large number of ambulatory patients is available suggests that the majority of patients in active treatment settings may also appreciate their opportunity to cooperate in the education of health science students.


Asunto(s)
Educación Médica , Pacientes , Enseñanza , Atención Ambulatoria , Canadá , Femenino , Humanos , Masculino , Anamnesis , Motivación , Satisfacción Personal , Enseñanza/métodos
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