Emily S. Miller

Metastatic osteosarcoma induced by inactivation of Rb and p53 in the osteoblast lineage.

Mutation of the RB-1 and p53 tumor suppressors is associated with the development of human osteosarcoma. With the goal of generating a mouse model of this disease, we used conditional and transgenic mouse strains to inactivate Rb and/or p53 specifically in osteoblast precursors. The resulting Rb;p53 double mutant (DKO) animals are viable but develop early onset osteosarcomas with complete penetrance. These tumors display many of the characteristics of human osteosarcomas, including being highly metastatic. We established cell lines from the DKO osteosarcomas to further investigate their properties. These immortalized cell lines are highly proliferative and they retain their tumorigenic potential, as judged by their ability to form metastatic tumors in immunocompromised mice. Moreover, they can be induced to differentiate and, depending on the inductive signal, will adopt either the osteogenic or adipogenic fate. Consistent with this multipotency, a significant portion of these tumor cells express Sca-1, a marker that is typically associated with stem cells/uncommitted progenitors. By assaying sorted cells in transplant assays, we demonstrate that the tumorigenicity of the osteosarcoma cell lines correlates with the presence of the Sca-1 marker. Finally, we show that loss of Rb and p53 in Sca-1-positive mesenchymal stem/progenitor cells is sufficient to yield transformed cells that can initiate osteosarcoma formation in vivo.

The Retinoblastoma Protein Tumor Suppressor Is Important for Appropriate Osteoblast Differentiation and Bone Development

Mutation of the retinoblastoma (RB) tumor suppressor gene is strongly linked to osteosarcoma formation. This observation and the documented interaction between the retinoblastoma protein (pRb) and Runx2 suggests that pRb is important in bone development. To assess this hypothesis, we used a conditional knockout strategy to generate pRb-deficient embryos that survive to birth. Analysis of these embryos shows that Rb inactivation causes the abnormal development and impaired ossification of several bones, correlating with an impairment in osteoblast differentiation. We further show that Rb inactivation acts to promote osteoblast differentiation in vitro and, through conditional analysis, establish that this occurs in a cell-intrinsic manner. Although these in vivo and in vitro differentiation phenotypes seem paradoxical, we find that Rb-deficient osteoblasts have an impaired ability to exit the cell cycle both in vivo and in vitro that can explain the observed differentiation defects. Consistent with this observation, we show that the cell cycle and the bone defects in Rb-deficient embryos can be suppressed by deletion of E2f1, a known proliferation inducer that acts downstream of Rb. Thus, we conclude that pRb plays a key role in regulating osteoblast differentiation by mediating the inhibition of E2F and consequently promoting cell cycle exit. (Mol Cancer Res 2008;6(9):1440–51)

Quality of Life for Long-Term Survivors of End-Stage Renal Disease

Eighteen children and adolescents who survived two years or longer in an attempt to manage their end-stage renal failure by transplantation were studied. The psychological adaptation of the young person to this form of management of renal disease was assessed by a semistructured interview of the patient and his parents. Fifty percent of the patients functioned at school or on the job and did not have depression. The remaining half did less well. In our institution a satisfactory quality of life required a successful transplant.

Consequences of a primary elective cesarean delivery across the reproductive life

OBJECTIVE: To estimate cumulative risks of morbidity associated with the choice of elective cesarean delivery for a first delivery. METHODS: A decision analytic model was designed to compare major adverse outcomes across a womans reproductive life associated with the choice of elective cesarean delivery compared with a trial of labor at a first delivery. Maternal outcomes assessed included maternal transfusion, hysterectomy, thromboembolism, operative injury, and death. Neonatal outcomes assessed included cerebral palsy and permanent brachial plexus palsy in the offspring. RESULTS: Choosing an initial cesarean delivery resulted in a 0.3% increased risk of a major adverse maternal outcome in the first pregnancy. In each subsequent pregnancy, the difference in composite maternal morbidity increased such that by the fourth pregnancy, the cumulative risk of a major adverse maternal outcome was nearly 10% in the elective primary cesarean delivery group, three times higher than women who initially underwent a trial of labor. Although the choice of an initial cesarean delivery resulted in 2.4 and 0.41 fewer cases of cerebral palsy and brachial plexus palsy, respectively, per 10,000 women in the first pregnancy, by a fourth pregnancy, the risk of a adverse neonatal outcome was higher among offspring of women who had chosen the initial elective cesarean delivery (0.368% compared with 0.363%). CONCLUSION: Maternal morbidity associated with the choice of primary elective cesarean delivery increases in each subsequent pregnancy and is greater in magnitude than that associated with the choice of a trial of labor. These increased risks are not offset by a substantive reduction in the risk of neonatal morbidity.

A universal mid-trimester transvaginal cervical length screening program and its associated reduced preterm birth rate

BACKGROUND Mid-trimester transvaginal cervical length assessment can identify women who are at risk of preterm birth and afford opportunities for preterm birth prevention. However, the incidence of a short cervix is low, and some physicians have questioned whether a universal screening program among women without a previous preterm birth would be beneficial. OBJECTIVE The purpose of this study was to examine whether the introduction of a universal transvaginal cervical length screening program is associated with a reduction in the preterm birth rate. STUDY DESIGN This is a cohort study of women with singleton gestations and without any previous preterm births who underwent an obstetric sonogram at 18-24 weeks of gestation and who had their delivery at a single tertiary institution from January 2007 to January 2014. In July 2011, a program was implemented in which all pregnant women who had a sonogram at 18-24 weeks of gestation were to receive a transvaginal cervical length measurement. The preterm birth rates were compared before and after the implementation of the universal cervical length screening program. Multivariable analysis was used to identify whether the universal cervical length screening program was associated independently with the frequency of preterm birth. The Breslow-Day test for homogeneity was used to assess whether any interaction existed in the association based on parity. RESULTS Of 64,207 eligible women, 46,598 underwent their mid-trimester sonogram before the universal cervical length screening program, and 17,609 underwent a sonogram after implementation of the program. Of the 17,590 women (99.9%) who agreed to cervical length measurement, 157 (0.89%) had a measurement of ≤25 mm. The introduction of the cervical length program was associated with a significant decrease in the frequency of preterm birth at <37 weeks of gestation (6.7% vs 6.0%; adjusted odds ratio, 0.82 [95% confidence interval, 0.76-0.88]), <34 weeks of gestation (1.9% vs 1.7%; adjusted odds ratio, 0.74 [95% confidence interval, 0.64-0.85]), and <32 weeks of gestation (1.1% vs 1.0%; adjusted odds ratio, 0.74 (95% confidence interval, 0.62-0.90]). This reduction in frequency of preterm birth primarily was due to a change in spontaneous (and not medically indicated) preterm births. The effect size for the reduction in preterm birth was similar in nulliparous and multiparous women with previous term births. CONCLUSION The introduction of a universal transvaginal cervical length screening program in women without a history of preterm birth is associated with a reduction in the frequency of preterm birth.

Does a postpartum hemorrhage patient safety program result in sustained changes in management and outcomes

We sought to determine whether the introduction of a postpartum hemorrhage (PPH) safety program was associated with changes in clinical practice and outcomes, and to examine whether these changes were sustained over time. In August 2008, a multidisciplinary PPH patient safety program was implemented at our single tertiary care hospital. We performed a cohort study of all women with PPH from August 2007 through December 2011. Changes in clinical practice and outcomes were compared before and after the intervention. Shewhart charts were used to examine sustainability of these changes over time. During the study period 52,819 women delivered, and 3105 (5.9%) experienced PPH. After the introduction of the program there was a significant increase in the use of uterotonic medications (P < .001), intrauterine balloon tamponade (P = .002), B-Lynch suture placement (P = .042), uterine artery embolization (P = .050), and cryoprecipitate use (P = .0222). Concomitantly, the number of days between admissions to the intensive care unit for PPH increased.

Indomethacin and antibiotics in examination-indicated cerclage: A randomized controlled trial

OBJECTIVE: To evaluate whether perioperative indomethacin and antibiotic administration at the time of examination-indicated cerclage placement prolongs gestation. METHODS: This is a randomized controlled trial performed at a single tertiary care hospital between March 2010 and November 2012. Women older than 18 years of age with a singleton pregnancy between 16 0/7 and 23 6/7 weeks of gestation undergoing an examination-indicated cerclage were eligible. Women were randomly assigned to receive either perioperative indomethacin and antibiotics or no perioperative prophylactic medications. The primary outcome was gestational latency after cerclage placement. Fifty women were required to be randomized to show, with 80% power, a 28-day improvement in latency assuming a latency without intervention of 50±35 days. RESULTS: Fifty-three patients were enrolled with three lost to follow-up. A greater proportion of pregnancies were prolonged by at least 28 days among women who received indomethacin and perioperative antibiotics (24 [92.3%] compared with 15 [62.5%], P=.01). However, gestational age at delivery and neonatal outcomes were statistically similar between groups. CONCLUSIONS: Among women receiving an examination-indicated cerclage in the second trimester, gestation was significantly more likely to be prolonged by 28 days among women who received perioperative indomethacin and antibiotics. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT01114516. LEVEL OF EVIDENCE: I

The association between cervical excisional procedures, midtrimester cervical length, and preterm birth

OBJECTIVE To determine whether a prior cervical excisional procedure (a loop electrosurgical excision procedure or cold knife cone) is associated with a short midtrimester cervical length (<3 cm) and whether having a short cervix explains the relationship between this procedure and preterm birth. STUDY DESIGN In this cohort study of women with a singleton pregnancy who underwent routine cervical length assessment between 18 and 24 weeks of gestation, women with a history of a prior cervical excisional procedure were compared with those without such a history. Bivariable and multivariable analyses were performed to identify whether a prior cervical excisional procedure remained an independent risk factor for preterm birth after controlling for cervical length. RESULTS Of the 6669 women who met inclusion criteria, 460 (6.9%) had a prior cervical excisional procedure. Mean cervical length was shorter (4.2 ± 0.9 cm vs 4.5 ± 0.9 cm, P < .001) and the proportion of women with a short cervix was higher (6.5% vs 1.5%, P < .001) in women with a prior cervical excisional procedure. In multivariable regression, both a short cervix (adjusted odds ratio, 6.19; 95% confidence interval, 3.85-9.95) and a prior cervical excisional procedure (adjusted odds ratio, 1.53; 95% confidence interval, 1.04-2.25) were significantly associated with preterm birth. CONCLUSION Women with a prior cervical excisional procedure have shorter midtrimester cervical lengths. Both a prior cervical excisional procedure and a short cervix were independently associated with preterm birth. These data suggest that the risk of preterm birth associated with a prior loop electrosurgical excision procedure or cold knife cone is not merely due to postsurgical shortening of the cervix.

Second-trimester Cervical Length Screening Among Asymptomatic Women: An Evaluation of Risk-based Strategies

OBJECTIVE: To estimate whether there are demographic or clinical characteristics that are associated with the likelihood of having a short cervix and whether these characteristics can be used to optimize cervical length screening. METHODS: This is a cohort study of women with a singleton gestation without a history of spontaneous preterm birth who underwent routine transvaginal second-trimester cervical length screening. Seven risk factors for preterm birth were compared by cervical length status. A multivariable logistic regression was performed to identify independent risk factors for a short cervix (cervical length 2.5 cm or less). Different prediction models for a short cervix, based on the number of risk factors present, were developed and test characteristics for cervical length assessment for different risk-based screening approaches were calculated. RESULTS: Of the 18,250 women screened, 164 (0.9%) had a short cervix. Maternal age and conception by in vitro fertilization were not significantly associated with a short cervix. However, black (adjusted odds ratio [OR] 3.77, 95% confidence interval [CI] 2.42–5.87) and Hispanic (adjusted OR 1.73, 95% CI 1.10–2.74) race–ethnicity, current tobacco use (adjusted OR 3.67, 95% CI 1.56–8.62), prior indicated preterm birth (adjusted OR 2.26, 95% CI 1.26–4.05), and having a prior cervical excisional procedure (adjusted OR 2.96, 95% CI 1.86–4.70) were independent risk factors for a short cervix. If only women with any of these variables present were offered transvaginal cervical length screening, the specificity increases from 62.8% for universal screening to 96.5% with a risk-based approach. The sensitivity with one variable present to offer transvaginal scanning was 62.8% and with two factors 14%. CONCLUSION: Limiting cervical length screening to women with at least one of the identified risk factors for a short cervix substantially decreases the number of ultrasonograms for cervical length assessment. However, this strategy results in nearly 40% of women with a short cervix not being ascertained. LEVEL OF EVIDENCE: II

Cost-Effectiveness Analysis of Morcellation Hysterectomy for Myomas

STUDY OBJECTIVE To estimate the cost-effectiveness of eliminating morcellation in the surgical treatment of leiomyomas from a societal perspective. DESIGN Cost-effectiveness analysis. DESIGN CLASSIFICATION Not applicable. SETTING A theoretical cohort of women undergoing hysterectomy for myoma disease large enough to require morcellation. PATIENTS None. INTERVENTIONS None. MEASUREMENTS A decision analysis model was constructed using probabilities, costs, and utility data from published sources. A cost-effectiveness analysis analyzing both quality-adjusted life years (QALYs) and cases of disseminated cancer was performed to determine the incremental cost-effectiveness ratio (ICER) of eliminating morcellation as a tool in the surgical treatment of leiomyomas. Costs and utilities were discounted using standard methodology. The base case included health care system costs and costs incurred by the patient for surgery-related disability. One-way sensitivity analyses were performed to assess the effect of various assumptions. MAIN RESULTS The cost to prevent 1 case of disseminated cancer was