Publications by authors named "Larry Platt"

7 Publications

  • Page 1 of 1

Treatment of Complicated Spontaneous Twin Anemia-Polycythemia Sequence via Fetoscopic Laser Ablation of the Vascular Communications.

Fetal Diagn Ther 2015 13;38(3):233-7. Epub 2014 Aug 13.

Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, Calif., USA.

Monochorionic diamniotic twins share a single placenta and have intertwin vascular communications that link the circulatory systems of the twins together. Twin anemia-polycythemia sequence (TAPS) is an atypical form of twin-twin transfusion syndrome (TTTS) caused by net transfer of blood from one fetus to the other and is characterized by large intertwin hemoglobin differences in the absence of oligohydramnios and polyhydramnios. This condition may develop spontaneously (sTAPS) or as a result of residual vascular communications after prior laser surgery. Because of the relatively low prevalence and lack of clinical awareness, the natural history of sTAPS is unclear and the antenatal treatment remains controversial. Case series of sTAPS have described expectant management with timed delivery, intrauterine blood transfusion, and fetoscopic laser treatment. Favorable outcomes have been described in cases of uncomplicated sTAPS that underwent conservative measures. However, we believe that there may be a subgroup of high-risk or complicated sTAPS patients that may benefit from definitive treatment afforded by fetoscopic laser therapy. We describe 3 complicated cases of sTAPS successfully treated with selective laser photocoagulation of communicating vessels. In 2 of the cases, placental pathology identified thrombosed fetal vessels of the polycythemic twin.
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September 2016

An examination of racial/ethnic disparities in children's oral health in the United States.

J Public Health Dent 2013 13;73(2):166-74. Epub 2012 Sep 13.

School of Medicine, Department of Pediatrics, University of California, San Francisco, CA 94110, USA.

Objective: To assess the extent factors other than race/ethnicity explain apparent racial/ethnic disparities in children's oral health and oral health care.

Methods: Data were from the 2007 National Survey of Children's Health, for children 2-17 years (n=82,020). Outcomes included parental reports of child's oral health status, receiving preventive dental care, and delayed dental care/unmet need. Model-based survey-data-analysis examined racial/ethnic disparities, controlling for child, family, and community/state (contextual) factors.

Results: Unadjusted results show large racial/ethnic oral health disparities. Compared with non-Hispanic White people, Hispanic and non-Hispanic-Black people were markedly more likely to be reported in only fair/poor oral health [odds ratios (ORs) (95% confidence intervals) 4.3 (4.0-4.6), 2.2 (2.0-2.4), respectively], lack preventive care [ORs 1.9 (1.8-2.0), 1.4 (1.3-1.5)], and experience delayed care/unmet need [ORs 1.5 (1.3-1.7), 1.4 (1.3-1.5)]. Adjusting for child, family, and community/state factors reduced racial/ethnic disparities. Adjusted ORs (AORs) for Hispanics and non-Hispanic Blacks attenuated for fair/poor oral health, to 1.6 (1.5-1.8) and 1.2 (1.1-1.4), respectively. Adjustment eliminated disparities for lacking preventive care [AORs 1.0 (0.9-1.1), 1.1 (1.1-1.2)] and in Hispanics for delayed care/unmet need (AOR 1.0). Among non-Hispanic Blacks, adjustment reversed the disparity for delayed care/unmet need [AOR 0.6 (0.6-0.7)].

Conclusions: Racial/ethnic disparities in children's oral health status and access were attributable largely to socioeconomic and health insurance factors. Efforts to decrease disparities may be more efficacious if targeted at social, economic, and other factors associated with minority racial/ethnic status and may have positive effects on all who share similar social, economic, and cultural characteristics.
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December 2013

Racial disparity trends in children's dental visits: US National Health Interview Survey, 1964-2010.

Pediatrics 2012 Aug 2;130(2):306-14. Epub 2012 Jul 2.

MassGeneral Hospital Center for Child and Adolescent Health Research and Policy, 15th Floor, C100, 100 Cambridge St, Boston, MA 02114, USA.

Background And Objective: Research that has repeatedly documented marked racial/ethnic disparities in US children's receipt of dental care at single time points or brief periods has lacked a historical policy perspective, which provides insight into how these disparities have evolved over time. Our objective was to examine the im-pact of national health policies on African American and white children's receipt of dental care from 1964 to 2010.

Methods: We analyzed data on race and dental care utilization for children aged 2 to 17 years from the 1964, 1976, 1989, 1999, and 2010 National Health Interview Survey. Dependent variables were as follows: child's receipt of a dental visit in the previous 12 months and child's history of never having had a dental visit. Primary independent variable was race (African American/white). We calculated sample prevalences, and χ(2) tests compared African American/white prevalences by year. We age-standardized estimates to the 2000 US Census.

Results: The percentage of African American and white children in the United States without a dental visit in the previous 12 months declined significantly from 52.4% in 1964 to 21.7% in 2010, whereas the percentage of children who had never had a dental visit declined significantly (P < .01) from 33.6% to 10.6%. Pronounced African American/white disparities in children's dental utilization rates, whereas large and statistically significant in 1964, attenuated and became nonsignificant by 2010.

Conclusions: We demonstrate a dramatic narrowing of African American/white disparities in 2 measures of children's receipt of dental services from 1964 to 2010. Yet, much more needs to be done before persistent racial disparities in children's oral health status are eliminated.
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August 2012

Assessing a multilevel model of young children's oral health with national survey data.

Community Dent Oral Epidemiol 2010 Aug 29;38(4):287-98. Epub 2010 Mar 29.

National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, MD, USA.

Objectives: To empirically test a multilevel conceptual model of children's oral health incorporating 22 domains of children's oral health across four levels: child, family, neighborhood and state.

Data Source: The 2003 National Survey of Children's Health, a module of the State and Local Area Integrated Telephone Survey conducted by the Centers for Disease Control and Prevention's National Center for Health Statistics, is a nationally representative telephone survey of caregivers of children.

Study Design: We examined child-, family-, neighborhood-, and state-level factors influencing parent's report of children's oral health using a multilevel logistic regression model, estimated for 26 736 children ages 1-5 years.

Principal Findings: Factors operating at all four levels were associated with the likelihood that parents rated their children's oral health as fair or poor, although most significant correlates are represented at the child or family level. Of 22 domains identified in our conceptual model, 15 domains contained factors significantly associated with young children's oral health. At the state level, access to fluoridated water was significantly associated with favorable oral health for children.

Conclusions: Our results suggest that efforts to understand or improve children's oral health should consider a multilevel approach that goes beyond solely child-level factors.
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August 2010

Influences on children's oral health: a conceptual model.

Pediatrics 2007 Sep;120(3):e510-20

University of California, Department of Pediatrics, 400 Parnassus Ave, Room AC01, Box 0374, San Francisco, CA 94143-0374, USA.

Objectives: Despite marked improvements over the past century, oral health in America is a significant problem: caries is the most common chronic disease of childhood. Much oral health research examines influences primarily in the oral cavity or focuses on a limited number of individual-level factors. The purpose of this article was to present a more encompassing conceptual model of the influences on children's oral health.

Methods: The conceptual model presented here was derived from the population health and social epidemiology fields, which have moved toward multilevel, holistic approaches to analyze the complex and interactive causes of children's health problems. It is based on a comprehensive review of major population and oral health literatures.

Results: A multilevel conceptual model is described, with the individual, family, and community levels of influence on oral health outcomes. This model incorporates the 5 key domains of determinants of health as identified in the population health literature: genetic and biological factors, the social environment, the physical environment, health behaviors, and dental and medical care. The model recognizes the presence of a complex interplay of causal factors. Last, the model incorporates the aspect of time, recognizing the evolution of oral health diseases (eg, caries) and influences on the child-host over time.

Conclusions: This conceptual model represents a starting point for thinking about children's oral health. The model incorporates many of the important breakthroughs by social epidemiologists over the past 25 years by including a broad range of genetic, social, and environmental risk factors; multiple pathways by which they operate; a time dimension; the notion of differential susceptibility and resilience; and a multilevel approach. The study of children's oral health from a global perspective remains largely in its infancy and is poised for additional development. This work can help inform how best to approach and improve children's oral health.
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September 2007

Late first-trimester placental disruption and subsequent gestational hypertension/preeclampsia.

Obstet Gynecol 2005 Mar;105(3):587-92

Evanston Hospital of Northwestern University Medical School, Evanston, Illinois 60201, USA.

Objective: To evaluate the potential relationship between placental disruption in weeks 13 and 14 and the subsequent development of gestational hypertension or preeclampsia.

Methods: Using subjects recruited during a randomized trial funded by the National Institute of Child Health and Human Development, which compared early amniocentesis and late transabdominal chorionic villus sampling (CVS) in weeks 13 and 14, rates of gestational hypertension and preeclampsia were compared between cases with varying degrees of placental disruption.

Results: A total of 3,698 of 3,775 randomized subjects had cytogenetically normal pregnancies and were analyzed. A significantly higher rate of hypertension/preeclampsia was observed in the late CVS group (5.4%, n = 1,878) compared with the early amniocentesis cohort (3.5%, n = 1,820; P = .005). This difference persisted after controlling for maternal age, body mass index, parity, previous preterm delivery, smoking, and fetal gender. Early amniocentesis cases were further stratified on the basis of whether the placenta had been penetrated (n = 460) or not (n = 1,360). Risk of hypertensive complications was lowest if the placenta was not traversed (3.4%), greater with placental penetration (3.9%), and highest when the placenta was directly sampled during CVS (5.4%, P = .02).

Conclusion: We hypothesize that focal disruption of the placenta at 13-14 weeks may increase the risk of hypertension/preeclampsia. These findings provide support for the theory that disturbances in early placentation lead subsequently to maternal hypertension.
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March 2005

The Maternal Phenylketonuria International Study: 1984-2002.

Pediatrics 2003 Dec;112(6 Pt 2):1523-9

Childrens Hospital of Los Angeles and the University of Southern California School of Medicine, Los Angeles, California 90027, USA.

Objective: The purpose of this report is to review the obstetric medical, psychological, and nutritional aspects and outcome of the women and offspring enrolled in the Maternal Phenylketonuria Study, which was established to assess the efficacy of a phenylalanine (Phe)-restricted diet in preventing the morbidity associated with this disorder.

Methods: A total of 382 women with hyperphenylalaninemia (HPA) were enrolled in the study and completed 572 pregnancies. Outcome measures were analyzed with chi2, Fisher exact text, analysis of variance, t test, Wilcoxon nonparametric test, and multiple logistic regression. Outcome measures were stratified according to maternal HPA classification and the time when dietary control was achieved.

Results: Optimal birth outcomes occurred when maternal blood Phe levels between 120 and 360 micromol/L were achieved by 8 to 10 weeks of gestation and maintained throughout pregnancy (trimester averages of 600 micromol/L). Mothers with mild HPA achieved similar birth outcomes as mothers who were in control preconceptually and those in control by 8 to 10 weeks of pregnancy.

Conclusions: Before conception, counseling and early entrance into a prenatal care program is essential in achieving optimal fetal outcome in women with HPA. The achievement of pre- and periconceptional dietary control with a Phe-restricted diet significantly decreased morbidity in the offspring of women with HPA.
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December 2003