ABSTRACT
PURPOSE: The common marmoset (Callithrix jacchus) provides an ideal model to study early development of primates, and an in vivo platform to validate conclusions from in vitro studies of human embryos and embryo models. Currently, however, no established staging atlas of marmoset embryonic development exists. Using high-resolution, longitudinal ultrasound scans on live pregnant marmosets, we present the first dynamic in vivo imaging of entire primate gestation beginning with attachment until the last day before birth. METHODS: Our study unveils the first dynamic images of an in vivo attached mammalian embryo developing in utero, and the intricacies of the delayed development period unique to the common marmoset amongst primates, revealing a window for somatic interventions. RESULTS: Established obstetric and embryologic measurements for each scan were used comparatively with the standardized Carnegie staging of human development to highlight similarities and differences. Our study also allows for tracking the development of major organs. We focus on the ontogeny of the primate heart and brain. Finally, input ultrasound images were used to train deep neural networks to accurately determine the gestational age. All our ultrasounds and staging data recording are posted online so that the atlas can be used as a community resource toward monitoring and managing marmoset breeding colonies. CONCLUSION: The temporal and spatial resolution of ultrasound achieved in this study demonstrates the promise of noninvasive imaging in the marmoset for the in vivo study of primate-specific aspects of embryonic and fetal development.
Subject(s)
Callithrix , Embryonic Development , Fetal Development , Ultrasonography, Prenatal , Callithrix/embryology , Animals , Female , Pregnancy , Ultrasonography, Prenatal/methods , Gestational Age , Humans , Embryo, Mammalian/diagnostic imagingABSTRACT
OBJECTIVE: The purpose of this study was to review screening mammograms obtained in one practice with the primary endpoint of determining the rate of detection of breast cancer and associated prognostic features in women 40-44 and 45-49 years old. MATERIALS AND METHODS: The retrospective cohort study included women in their 40s with breast cancer detected at screening from June 2014 through May 2016. The focus was on cancer detection rate, pathologic findings, and risk factors. RESULTS: A total of 32,762 screens were performed, and 808 biopsies were recommended. These biopsies yielded 224 breast cancers (cancer detection rate, 6.84 per 1000 screens). Women 40-49 years old had 18.8% of cancers detected; 50-59 years, 21.8%; 60-69 years, 32.6%; and 70-79 years, 21.4%. Among the 40- to 49-year-old women, women 40-44 years old underwent 5481 (16.7%) screens, had 132 biopsies recommended, and had 20 breast cancers detected (cancer detection rate, 3.6/1000). Women 45-49 years old underwent 5319 (16.2%) screens, had 108 biopsies recommended, and had 22 breast cancers detected (cancer detection rate, 4.1/1000). Thus, women 40-44 years old had 8.9% and women 45-49 years old had 9.8% of all screen-detected breast cancers. Of these only a small percentage of women with detected cancers had a first-degree relative with breast cancer (40-44 years, 15%; 45-49 years, 32%) or a BRCA mutation (40-44 years, 5%; 45-49 years, 5%), and over 60% of the cancers were invasive. CONCLUSION: Women 40-49 years old had 18.8% of all screen-detected breast cancers. The two cohorts (40-44 and 45-49 years old) had similar incidences of screen-detected breast cancer (8.9%, 9.8%) and cancer detection rates within performance benchmark standards, supporting a similar recommendation for both cohorts and the American College of Radiology recommendation of annual screening mammography starting at age 40.