Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
JAMA ; 328(15): 1523-1533, 2022 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-36255426

RESUMEN

Importance: Data on the epidemiology of mild to moderately severe COVID-19 are needed to inform public health guidance. Objective: To evaluate associations between 2 or 3 doses of mRNA COVID-19 vaccine and attenuation of symptoms and viral RNA load across SARS-CoV-2 viral lineages. Design, Setting, and Participants: A prospective cohort study of essential and frontline workers in Arizona, Florida, Minnesota, Oregon, Texas, and Utah with COVID-19 infection confirmed by reverse transcriptase-polymerase chain reaction testing and lineage classified by whole genome sequencing of specimens self-collected weekly and at COVID-19 illness symptom onset. This analysis was conducted among 1199 participants with SARS-CoV-2 from December 14, 2020, to April 19, 2022, with follow-up until May 9, 2022, reported. Exposures: SARS-CoV-2 lineage (origin strain, Delta variant, Omicron variant) and COVID-19 vaccination status. Main Outcomes and Measures: Clinical outcomes included presence of symptoms, specific symptoms (including fever or chills), illness duration, and medical care seeking. Virologic outcomes included viral load by quantitative reverse transcriptase-polymerase chain reaction testing along with viral viability. Results: Among 1199 participants with COVID-19 infection (714 [59.5%] women; median age, 41 years), 14.0% were infected with the origin strain, 24.0% with the Delta variant, and 62.0% with the Omicron variant. Participants vaccinated with the second vaccine dose 14 to 149 days before Delta infection were significantly less likely to be symptomatic compared with unvaccinated participants (21/27 [77.8%] vs 74/77 [96.1%]; OR, 0.13 [95% CI, 0-0.6]) and, when symptomatic, those vaccinated with the third dose 7 to 149 days before infection were significantly less likely to report fever or chills (5/13 [38.5%] vs 62/73 [84.9%]; OR, 0.07 [95% CI, 0.0-0.3]) and reported significantly fewer days of symptoms (10.2 vs 16.4; difference, -6.1 [95% CI, -11.8 to -0.4] days). Among those with Omicron infection, the risk of symptomatic infection did not differ significantly for the 2-dose vaccination status vs unvaccinated status and was significantly higher for the 3-dose recipients vs those who were unvaccinated (327/370 [88.4%] vs 85/107 [79.4%]; OR, 2.0 [95% CI, 1.1-3.5]). Among symptomatic Omicron infections, those vaccinated with the third dose 7 to 149 days before infection compared with those who were unvaccinated were significantly less likely to report fever or chills (160/311 [51.5%] vs 64/81 [79.0%]; OR, 0.25 [95% CI, 0.1-0.5]) or seek medical care (45/308 [14.6%] vs 20/81 [24.7%]; OR, 0.45 [95% CI, 0.2-0.9]). Participants with Delta and Omicron infections who received the second dose 14 to 149 days before infection had a significantly lower mean viral load compared with unvaccinated participants (3 vs 4.1 log10 copies/µL; difference, -1.0 [95% CI, -1.7 to -0.2] for Delta and 2.8 vs 3.5 log10 copies/µL, difference, -1.0 [95% CI, -1.7 to -0.3] for Omicron). Conclusions and Relevance: In a cohort of US essential and frontline workers with SARS-CoV-2 infections, recent vaccination with 2 or 3 mRNA vaccine doses less than 150 days before infection with Delta or Omicron variants, compared with being unvaccinated, was associated with attenuated symptoms, duration of illness, medical care seeking, or viral load for some comparisons, although the precision and statistical significance of specific estimates varied.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Vacunación , Carga Viral , Adulto , Femenino , Humanos , Masculino , COVID-19/diagnóstico , COVID-19/genética , COVID-19/prevención & control , COVID-19/virología , Vacunas contra la COVID-19/administración & dosificación , Vacunas contra la COVID-19/uso terapéutico , Estudios Prospectivos , ARN Viral/análisis , ARN Viral/genética , ADN Polimerasa Dirigida por ARN , SARS-CoV-2/genética , Vacunación/estadística & datos numéricos , Estados Unidos/epidemiología , Carga Viral/efectos de los fármacos , Carga Viral/genética , Carga Viral/estadística & datos numéricos , Secuenciación Completa del Genoma , Infecciones Asintomáticas/epidemiología , Infecciones Asintomáticas/terapia , Factores de Tiempo , Aceptación de la Atención de Salud/estadística & datos numéricos , Vacunas de ARNm
2.
Physiol Rep ; 10(7): e15233, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35384387

RESUMEN

Women with polycystic ovary syndrome (PCOS) demonstrate gonadotropin-releasing hormone (GnRH) pulse generator resistance to suppression with 7 days of progesterone and estradiol administration. It remains unknown whether such women demonstrate impairments in acute progesterone negative feedback on LH pulse frequency or progesterone positive feedback on gonadotropin release. This was a randomized, double-blind, placebo-controlled crossover study designed to test the hypothesis that acute, progesterone-related suppression of LH pulse frequency and progesterone-related augmentation of gonadotropin release are impaired in PCOS. Twelve normally cycling women and 12 women with PCOS completed study. Volunteers were pretreated with transdermal estradiol (0.2 mg/day) for 3 days and then underwent a frequent blood sampling study (20:00-20:00 h), during which they received micronized progesterone (100 mg) or placebo at 06:00 h. In a second study admission, volunteers received the intervention they did not receive during the first admission, but the protocol was otherwise identical. The primary outcome measures were LH secretory characteristics and circulating gonadotropin concentrations. Exogenous progesterone did not reduce LH pulse frequency in either group. Mean LH, pulsatile LH secretion, LH pulse mass, and mean FSH increased more with progesterone compared to placebo in both groups. Although trends toward less pronounced changes in LH pulse mass and pulsatile LH secretion were observed in the PCOS group, these differences were not statistically significant. In summary, exogenous progesterone did not suppress LH pulse frequency within 12 hours in estradiol-pretreated women, and the positive feedback effect of progesterone on gonadotropin release was not demonstrably impaired in PCOS. NEW & NOTEWORTHY: This study indicated that exogenous progesterone does not reduce LH pulse frequency within 12 h in women with PCOS, but progesterone acutely increased gonadotropin in these women. This study suggested that progesterone-related augmentation of gonadotropin release may be impaired in PCOS compared to normally cycling women, but this finding was not statistically significant.


Asunto(s)
Síndrome del Ovario Poliquístico , Progesterona , Estudios Cruzados , Estradiol , Retroalimentación , Femenino , Hormona Folículo Estimulante , Hormona Liberadora de Gonadotropina , Gonadotropinas , Humanos , Hormona Luteinizante , Síndrome del Ovario Poliquístico/tratamiento farmacológico
3.
Influenza Other Respir Viruses ; 16(3): 585-593, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35023288

RESUMEN

BACKGROUND: We sought to evaluate the impact of changes in estimates of COVID-19 vaccine effectiveness on the incidence of laboratory-confirmed infection among frontline workers at high risk for SARS-CoV-2. METHODS: We analyzed data from a prospective frontline worker cohort to estimate the incidence of COVID-19 by month as well as the association of COVID-19 vaccination, occupation, demographics, physical distancing, and mask use with infection risk. Participants completed baseline and quarterly surveys, and each week self-collected mid-turbinate nasal swabs and reported symptoms. RESULTS: Among 1018 unvaccinated and 3531 fully vaccinated workers, the monthly incidence of laboratory-confirmed SARS-CoV-2 infection in January 2021 was 13.9 (95% confidence interval [CI]: 10.4-17.4), declining to 0.5 (95% CI -0.4-1.4) per 1000 person-weeks in June. By September 2021, when the Delta variant predominated, incidence had once again risen to 13.6 (95% CI 7.8-19.4) per 1000 person-weeks. In contrast, there was no reportable incidence among fully vaccinated participants at the end of January 2021, and incidence remained low until September 2021 when it rose modestly to 4.1 (95% CI 1.9-3.8) per 1000. Below average facemask use was associated with a higher risk of infection for unvaccinated participants during exposure to persons who may have COVID-19 and vaccinated participants during hours in the community. CONCLUSIONS: COVID-19 vaccination was significantly associated with a lower risk of SARS-CoV-2 infection despite Delta variant predominance. Our data demonstrate the added protective benefit of facemask use among both unvaccinated and vaccinated frontline workers.


Asunto(s)
COVID-19 , Socorristas , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19 , Atención a la Salud , Humanos , Incidencia , Estudios Prospectivos , SARS-CoV-2/genética , Vacunación
4.
J Clin Endocrinol Metab ; 103(3): 1112-1121, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-29300925

RESUMEN

Context: During normal, early puberty, luteinizing hormone (LH) pulse frequency is low while awake but increases during sleep. Mechanisms underlying such changes are unclear, but a small study in early pubertal girls suggested that differential wake-sleep sensitivity to progesterone negative feedback plays a role. Objective: To test the hypothesis that progesterone acutely reduces waking LH pulse frequency more than sleep-associated pulse frequency in late pubertal girls. Design: Randomized, placebo-controlled, double-blinded crossover study. Setting: Academic clinical research unit. Participants: Eleven normal, postmenarcheal girls, ages 12 to 15 years. Intervention: Subjects completed two 18-hour admissions in separate menstrual cycles (cycle days 6 to 11). Frequent blood sampling for LH assessment was performed at 1800 to 1200 hours; sleep was encouraged at 2300 to 0700 hours. Either oral micronized progesterone (0.8 mg/kg/dose) or placebo was given at 0700, 1500, 2300, and 0700 hours, before and during the first admission. A second admission, performed at least 2 months later, was identical to the first except that placebo was exchanged for progesterone or vice versa (treatment crossover). Main Outcome Measures: LH pulse frequency during waking and sleeping hours. Results: Progesterone reduced waking LH pulse frequency by 26% (P = 0.019), with no change observed during sleep (P = 0.314). The interaction between treatment condition (progesterone vs placebo) and sleep status (wake vs sleep) was highly significant (P = 0.007). Conclusions: In late pubertal girls, progesterone acutely reduced waking LH pulse frequency more than sleep-associated pulse frequency. Differential wake-sleep sensitivity to progesterone negative feedback may direct sleep-wake LH pulse frequency changes across puberty.


Asunto(s)
Hormona Luteinizante/metabolismo , Menarquia/fisiología , Progesterona/administración & dosificación , Progestinas/administración & dosificación , Sueño/fisiología , Adolescente , Niño , Ritmo Circadiano/fisiología , Estudios Cruzados , Método Doble Ciego , Esquema de Medicación , Femenino , Hormona Liberadora de Gonadotropina/metabolismo , Humanos , Hormona Luteinizante/sangre
5.
J Clin Endocrinol Metab ; 103(1): 263-270, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29095983

RESUMEN

Context: Polycystic ovary syndrome (PCOS) and adolescent hyperandrogenism (HA) are characterized by rapid luteinizing hormone (LH) pulse frequency. This partly reflects impaired gonadotropin-releasing hormone pulse generator (hypothalamic) sensitivity to progesterone (P4) negative feedback. We assessed whether metformin may improve P4 sensitivity in adolescent HA, for which it is prescribed widely. Objective: To test the hypothesis that metformin improves hypothalamic P4 sensitivity in adolescent HA. Design: Nonrandomized, interventional trial. Setting: Academic clinical research unit. Participants: Ten adolescent girls with HA. Intervention: The girls underwent LH sampling every 10 minutes for 11 hours, at study baseline and after 7 days of oral P4 and estradiol (E2). Participants then took metformin (1 g twice daily) for 9.4 to 13.7 weeks, after which participants again underwent frequent LH sampling before and after 7 days of oral P4 and E2 (while continuing metformin). Total and free testosterone (T) and fasting insulin were assessed at each admission. At admissions 1 and 3, 2-hour oral glucose tolerance tests were performed. Main Outcome Measure: Metformin-related change in hypothalamic P4 sensitivity index [percent change in LH pulse frequency (before vs after P4 and E2) divided by day 7 P4 level]. Results: Free T levels decreased by 29% with metformin (P = 0.0137). Measures of hyperinsulinemia and P4 sensitivity index did not significantly change with metformin use. Conclusion: Short-term metformin use improved biochemical hyperandrogenemia, but did not improve hypothalamic sensitivity to P4 suppression, in adolescent girls.


Asunto(s)
Retroalimentación Fisiológica/efectos de los fármacos , Hiperandrogenismo/tratamiento farmacológico , Hormona Luteinizante/metabolismo , Metformina/uso terapéutico , Progesterona/antagonistas & inhibidores , Flujo Pulsátil/efectos de los fármacos , Adolescente , Femenino , Estudios de Seguimiento , Prueba de Tolerancia a la Glucosa , Humanos , Hiperandrogenismo/metabolismo , Hipoglucemiantes/uso terapéutico , Resistencia a la Insulina , Pronóstico
7.
J Trauma ; 70(5): 1208-12, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21610434

RESUMEN

BACKGROUND: Angiographic embolization (AE) has emerged as an important therapy for patients with nonvariceal upper gastrointestinal bleeding (UGIB). We hypothesized that discrete factors predictive of AE failure could be identified. METHODS: A retrospective review was performed for patients with nonvariceal UGIB who underwent AE from 1999 to 2009 at Penn State Milton S. Hershey Medical Center. AE clinical failure was defined as requirement for another intervention (surgery, endoscopic therapy, or another AE) for nonvariceal UGIB and/or death from bleeding after AE. Statistical analysis was performed using Fisher's exact test and Student's t test to explore the risk of AE failure. RESULTS: Of 48 total AE cases, 17 patients (35.4%) had clinically failed AE. Mortality rate was significantly higher in patients with AE clinical failure than in patients with AE clinical success (64.7% vs. 12.9%, p=0.001). Factors associated with AE clinical failure include anticoagulant use before admission (p=0.001), use of corticosteroids before admission (p=0.045), pre-AE vasopressor use (p=0.038), and embolization using either coils alone (p=0.05) or using coils with or without additional embolic materials (p=0.018). CONCLUSIONS: AE clinical failure portends poor prognosis. Caution should be exercised when considering AE, particularly AE using coils, in patients with a history of anticoagulant, corticosteroid, or vasopressor use.


Asunto(s)
Angiografía/métodos , Embolización Terapéutica/métodos , Hemorragia Gastrointestinal/terapia , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Hemorragia Gastrointestinal/diagnóstico por imagen , Hemorragia Gastrointestinal/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Pennsylvania/epidemiología , Pronóstico , Estudios Prospectivos , Factores de Riesgo , Tasa de Supervivencia/tendencias , Insuficiencia del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...