RESUMEN
Mechanosensitive Merkel cells are thought to have finite lifespans, but controversy surrounds the frequency of their replacement and which precursor cells maintain the population. We found by embryonic EdU administration that Merkel cells undergo terminal cell division in late embryogenesis and survive long into adulthood. We also found that new Merkel cells are produced infrequently during normal skin homeostasis and that their numbers do not change during natural or induced hair cycles. In contrast, live imaging and EdU experiments showed that mild mechanical injury produced by skin shaving dramatically increases Merkel cell production. We confirmed with genetic cell ablation and fate-mapping experiments that new touch dome Merkel cells in adult mice arise from touch dome keratinocytes. Together, these independent lines of evidence show that Merkel cells in adult mice are long-lived, are replaced rarely during normal adult skin homeostasis, and that their production can be induced by repeated shaving. These results have profound implications for understanding sensory neurobiology and human diseases such as Merkel cell carcinoma.
Asunto(s)
Homeostasis , Células de Merkel/fisiología , Piel/citología , Animales , Carcinoma de Células de Merkel/etiología , Proliferación Celular , Desoxiuridina/análogos & derivados , Desoxiuridina/metabolismo , Femenino , Proteínas Fluorescentes Verdes , Ratones , Ratones Endogámicos C57BLRESUMEN
Given the association of adverse pregnancy outcomes with risk of developing cardiovascular disease and cardiac events later in life, our institution launched a CardioObstetrics (CardioOB) program aimed to provide long-term care for patients at risk. We performed a retrospective cohort study in order to investigate which patient characteristics were associated with CardioOB follow-up following the inception of the program. We identified several sociodemographic factors and pregnancy characteristics such as increased maternal age, non-English language preferred, married marital status, referral during the antepartum period, and discharged with antihypertensive medications after delivery associated with a higher likelihood of CardioOB follow-up.
Asunto(s)
Preeclampsia , Factores Sociodemográficos , Embarazo , Femenino , Humanos , Estudios de Seguimiento , Estudios Retrospectivos , Factores de RiesgoRESUMEN
BACKGROUND: Hypertensive disorders of pregnancy are one of the leading causes of maternal mortality and severe morbidity. The American College of Obstetricians and Gynecologists recommends treatment of persistent severe hypertension because this has been shown to improve overall outcomes. Treatment remains inconsistent and may be influenced by patient-level sociodemographic and clinical characteristics. OBJECTIVE: This study aimed to identify which factors are associated with nonadherence to an institutional protocol for the treatment of severe hypertension in pregnancy. STUDY DESIGN: Retrospective cohort study of patients who had persistent severe hypertension (≥2 systolic blood pressures ≥160 mm Hg and/or diastolic blood pressures >110 mm Hg between 15 and 60 minutes apart) during their delivery hospitalization in 3 hospitals within an integrated health system from February 1, 2018 to March 1, 2020. Adherence to an institutional protocol was defined as receiving antihypertensive medication within 1 hour of a second severe blood pressure measurement. Demographic information, medical comorbidities, and delivery hospitalization characteristics were compared between women who received treatment based on institutional protocol and those who did not. Patient zone improvement plan codes were linked to neighborhood-level data from the US Census Bureau's American Community Survey to extract socioeconomic characteristics. A multivariable logistic regression was performed to evaluate factors associated with delayed treatment while adjusting for potential confounders. RESULTS: Of the 996 patients included, 449 (45%) received treatment within 60 minutes and 547 (55%) did not. Having an elevated, nonsevere range blood pressure (adjusted odds ratio, 0.55; 95% confidence interval, 0.38-0.79) or a severe range blood pressure (adjusted odds ratio, 0.25; 95% confidence interval, 0.16-0.38) on admission, persistent severe hypertension ≥1 hour before or after delivery (adjusted odds ratio, 0.27; 95% confidence interval, 0.27-0.45), and chronic hypertension (adjusted odds ratio, 0.58; 95% confidence interval, 0.37-0.93) were associated with timely treatment. Hospital site (adjusted odds ratio, 1.97; 95% confidence interval, 1.18-3.28) and increasing gestational age (adjusted odds ratio, 1.14; 95% confidence interval, 1.07-1.21) were associated with nonadherence to treatment protocol. A subanalysis evaluating treatment in 344 (35%) patients who had a nonelevated blood pressure on admission showed that White race, persistent severe hypertension within 1 hour of delivery, increasing gestational age, body mass index, twin gestation, preferred language other than English or Spanish, and a higher neighborhood unemployment rate were associated with nonadherence to treatment protocol. CONCLUSION: Several factors were associated with nonadherence to an institutional protocol for treatment of persistent severe hypertension. Provider bias may impact whether treatment is executed or not. Awareness of these risk factors may improve timely administration of antihypertensive medication in pregnant and postpartum patients.