Are researchers in academic medicine flourishing? A survey of midcareer Ph.D. and physician investigators

Introduction

Midcareer research faculty are a vital part of the advancement of science in U.S. medical schools, but there are troubling trends in recruitment, retention, and burnout rates.

Methods

The primary sampling frame for this online survey was recipients of a single R01 or equivalent and/or K-award from 2013 to 2019. Inclusion criteria were 3-14 years at a U.S. medical school and rank of associate professor or two or more years as assistant professor. Forty physician investigators and Ph.D. scientists volunteered for a faculty development program, and 106 were propensity-matched controls. Survey items covered self-efficacy in career, research, work-life; vitality/burnout; relationships, inclusion, trust; diversity; and intention to leave academic medicine.

Results

The majority (52%) reported receiving poor mentoring; 40% experienced high burnout and 41% low vitality, which, in turn, predicted leaving intention (P < 0.0005). Women were more likely to report high burnout (P = 0.01) and low self-efficacy managing work and personal life (P = 0.01) and to be seriously considering leaving academic medicine than men (P = 0.003). Mentoring quality (P < 0.0005) and poor relationships, inclusion, and trust (P < 0.0005) predicted leaving intention. Non-underrepresented men were very likely to report low identity self-awareness (65%) and valuing differences (24%) versus underrepresented men (25% and 0%; P < 0.0005). Ph.D.s had lower career advancement self-efficacy than M.D.s (P < .0005).

Conclusions

Midcareer Ph.D. and physician investigators faced significant career challenges. Experiences diverged by underrepresentation, gender, and degree. Poor quality mentoring was an issue for most. Effective mentoring could address the concerns of this vital component of the biomedical workforce.

Substance use patterns in 9-10 year olds: Baseline findings from the adolescent brain cognitive development (ABCD) study

BACKGROUND

The Adolescent Brain Cognitive Development ™ Study (ABCD Study®) is an open-science, multi-site, prospective, longitudinal study following over 11,800 9- and 10-year-old youth into early adulthood. The ABCD Study aims to prospectively examine the impact of substance use (SU) on neurocognitive and health outcomes. Although SU initiation typically occurs during teen years, relatively little is known about patterns of SU in children younger than 12.

METHODS

This study aims to report the detailed ABCD Study® SU patterns at baseline (n = 11,875) in order to inform the greater scientific community about cohort's early SU. Along with a detailed description of SU, we ran mixed effects regression models to examine the association between early caffeine and alcohol sipping with demographic factors, externalizing symptoms and parental history of alcohol and substance use disorders (AUD/SUD).

PRIMARY RESULTS

At baseline, the majority of youth had used caffeine (67.6 %) and 22.5 % reported sipping alcohol (22.5 %). There was little to no reported use of other drug categories (0.2 % full alcohol drink, 0.7 % used nicotine, <0.1 % used any other drug of abuse). Analyses revealed that total caffeine use and early alcohol sipping were associated with demographic variables (p's<.05), externalizing symptoms (caffeine p = 0002; sipping p = .0003), and parental history of AUD (sipping p = .03).

CONCLUSIONS

ABCD Study participants aged 9-10 years old reported caffeine use and alcohol sipping experimentation, but very rare other SU. Variables linked with early childhood alcohol sipping and caffeine use should be examined as contributing factors in future longitudinal analyses examining escalating trajectories of SU in the ABCD Study cohort.

Baseline brain function in the preadolescents of the ABCD Study

The Adolescent Brain Cognitive Development (ABCD) Study® is a 10-year longitudinal study of children recruited at ages 9 and 10. A battery of neuroimaging tasks are administered biennially to track neurodevelopment and identify individual differences in brain function. This study reports activation patterns from functional MRI (fMRI) tasks completed at baseline, which were designed to measure cognitive impulse control with a stop signal task (SST; N = 5,547), reward anticipation and receipt with a monetary incentive delay (MID) task (N = 6,657) and working memory and emotion reactivity with an emotional N-back (EN-back) task (N = 6,009). Further, we report the spatial reproducibility of activation patterns by assessing between-group vertex/voxelwise correlations of blood oxygen level-dependent (BOLD) activation. Analyses reveal robust brain activations that are consistent with the published literature, vary across fMRI tasks/contrasts and slightly correlate with individual behavioral performance on the tasks. These results establish the preadolescent brain function baseline, guide interpretation of cross-sectional analyses and will enable the investigation of longitudinal changes during adolescent development.

Correspondence Between Perceived Pubertal Development and Hormone Levels in 9-10 Year-Olds From the Adolescent Brain Cognitive Development Study

Aim

To examine individual variability between perceived physical features and hormones of pubertal maturation in 9-10-year-old children as a function of sociodemographic characteristics.

Methods

Cross-sectional metrics of puberty were utilized from the baseline assessment of the Adolescent Brain Cognitive Development (ABCD) Study-a multi-site sample of 9-10 year-olds (n = 11,875)-and included perceived physical features via the pubertal development scale (PDS) and child salivary hormone levels (dehydroepiandrosterone and testosterone in all, and estradiol in females). Multi-level models examined the relationships among sociodemographic measures, physical features, and hormone levels. A group factor analysis (GFA) was implemented to extract latent variables of pubertal maturation that integrated both measures of perceived physical features and hormone levels.

Results

PDS summary scores indicated more males (70%) than females (31%) were prepubertal. Perceived physical features and hormone levels were significantly associated with child's weight status and income, such that more mature scores were observed among children that were overweight/obese or from households with low-income. Results from the GFA identified two latent factors that described individual differences in pubertal maturation among both females and males, with factor 1 driven by higher hormone levels, and factor 2 driven by perceived physical maturation. The correspondence between latent factor 1 scores (hormones) and latent factor 2 scores (perceived physical maturation) revealed synchronous and asynchronous relationships between hormones and concomitant physical features in this large young adolescent sample.

Conclusions

Sociodemographic measures were associated with both objective hormone and self-report physical measures of pubertal maturation in a large, diverse sample of 9-10 year-olds. The latent variables of pubertal maturation described a complex interplay between perceived physical changes and hormone levels that hallmark sexual maturation, which future studies can examine in relation to trajectories of brain maturation, risk/resilience to substance use, and other mental health outcomes.

The Potential for Health Information Technology Tools to Reduce Racial Disparities in Maternal Morbidity and Mortality

Health information technology (health IT) potentially is a promising vital lever to address racial and ethnic, socioeconomic, and geographic disparities in maternal morbidity and mortality (MMM). This is especially relevant given that approximately 60% of maternal deaths are considered preventable.1-36 Interventions that leverage health IT tools to target the underlying drivers of disparities at the patient, clinician, and health care system levels potentially could reduce disparities in quality of care throughout the continuum (antepartum, intrapartum, and postpartum) of maternity care. This article presents an overview of the research (and gaps) on the potential of health IT tools to document SDoH and community-level geocoded data in EHR-based CDS systems, minimize implicit bias, and improve adherence to clinical guidelines and coordinated care to inform multilevel (patient, clinician, system) interventions throughout the continuum of maternity care for health disparity populations impacted by MMM. Telemedicine models for improving access in rural areas and new technologies for risk assessment and disease management (e.g., regarding preeclampsia) also are discussed.

Perinatal Depression: Challenges and Opportunities

Perinatal depression (PND) is a major depressive episode during pregnancy or within 4 weeks after childbirth up to a year. Risk factors for PND include stressful life events, history of depression, poor social support, unplanned and unwanted pregnancies, poor relationship quality, current or previous abuse, and low socioeconomic status. This mental disorder has been shown to have negative effects on mothers' quality of life and their intimate relationships, birth outcomes, and breastfeeding likelihood, as well as long-term effects on children's cognitive and emotional development. To date, no nationally representative study has examined whether there are socioeconomic and/or racial/ethnic differences in PND. This study discusses the prevalence and risk factors for PND, as well as its health consequences for mothers and children, the reasons for its underreporting and undertreatment, the evidence for different screening instruments and different treatment options, and the existing supportive policies to address this disorder in the United States. We conclude with outlining next steps in addressing the gaps in the literature on PND.

A Comprehensive Overview of the Physical Health of the Adolescent Brain Cognitive Development Study Cohort at Baseline

Physical health in childhood is crucial for neurobiological as well as overall development, and can shape long-term outcomes into adulthood. The landmark, longitudinal Adolescent Brain Cognitive Development Study^SM (ABCD study^®), was designed to investigate brain development and health in almost 12,000 youth who were recruited when they were 9-10 years old and will be followed through adolescence and early adulthood. The overall goal of this paper is to provide descriptive analyses of physical health measures in the ABCD study at baseline, including but not limited to sleep, physical activity and sports involvement, and body mass index. Further this summary will describe how physical health measures collected from the ABCD cohort compare with current normative data and clinical guidelines. We propose this data set has the potential to facilitate clinical recommendations and inform national standards of physical health in this age group. This manuscript will also provide important information for ABCD users and help guide analyses investigating physical health including new avenues for health disparity research as it pertains to adolescent and young adult development.

The Association of Health Reform and Infant Health: Evidence from Massachusetts

OBJECTIVE

To estimate whether the incidence of low birthweight and rates of infant mortality were associated with Massachusetts health reform in the overall population and for subgroups that are at higher risk for poor health outcomes.

DATA SOURCES

Individual-level data on birthweight were obtained from the National Center for Health Statistics detailed natality files, and aggregated county-level mortality rates were generated from linked birth-death files. We used restricted versions of each file that had intact state and substate geographic identifiers.

RESEARCH DESIGN

We employed a quasi-experimental difference-in-differences design.

PRINCIPAL RESULTS

We found small and statistically nonsignificant associations between the reform and the incidence of low birthweight and infant mortality rates. Results were consistent across a number of subgroups and were robust to alternative comparison groups and alternative modeling assumptions.

CONCLUSIONS

We found no evidence that the Massachusetts reform was associated with improvements in individual low birthweights or county-level infant mortality rates, despite increasing health insurance coverage rates for adult women of child-bearing age. Because our mortality analysis was ecological, we are not able to draw conclusions about how an individual-level health insurance intervention for uninsured pregnant women would affect the mortality outcomes of their infants.

Determinants of breastfeeding initiation and cessation among employed mothers: a prospective cohort study

Background

The U.S. continues to have one of the lowest breastfeeding rates in the industrialized world. Studies have shown that full-time employment and early return to work decreased breastfeeding duration, but little is known about the relationship between leave policies and breastfeeding initiation and cessation. This study aimed to identify workplace-related barriers and facilitators associated with breastfeeding initiation and cessation in the first 6 months postpartum.

Methods

A prospective cohort study design was utilized to recruit 817 Minnesota women aged 18 and older while hospitalized for childbirth. Selection criteria included English-speaking, employed mothers with a healthy, singleton birth. These women were followed up using telephone interviews at 6 weeks, 12 weeks, and 6 months after childbirth. The main study outcomes were breastfeeding initiation, measured during hospital enrollment, and breastfeeding cessation by 6 months postpartum.

Results

Women were 30 years old; 86 % were White, and 73 % were married. Breastfeeding rates were 81 % at childbirth, 67 % at 6 weeks, 49 % at 12 weeks, and 33 % at 6 months postpartum. Logistic regression revealed the odds of breastfeeding initiation were higher for women who: held professional jobs, were primiparae, had graduate degree, did not smoke prenatally, had no breastfeeding problems, and had family or friends who breastfeed. Survival analyses showed the hazard for breastfeeding cessation by 6 months was: higher for women who returned to work at any time during the 6 months postpartum versus those who did not return, lower for professional workers, higher among single than married women, higher for every educational category compared to graduate school, and higher for those with no family or friends who breastfeed.

Conclusions

While employer paid leave policy did not affect breastfeeding initiation or cessation, women who took shorter leaves were more likely to stop breastfeeding in the first 6 months postpartum. Future research should examine women’s awareness of employer policies regarding paid and unpaid leave.

Racial/Ethnic Differences in Unintended Pregnancy: Evidence From a National Sample of U.S. Women

INTRODUCTION

Racial and ethnic minorities experience greater burden of unintended pregnancy in the U.S. This study examined the factors associated with racial and ethnic disparities in unintended pregnancy among women in the U.S. using the social ecological model.

METHODS

This study utilized the National Survey of Family Growth data from 2006 to 2010. Data were analyzed in Autumn 2014 and Winter 2015. Decomposition analyses examined which intrapersonal, interpersonal, institutional, community, and public policy factors explained racial and ethnic disparities in unintended pregnancy.

RESULTS

Unadjusted analyses found that black and Hispanic women had a greater likelihood of unintended pregnancy compared with white women. Decomposition models explained 51% of the disparity in unintended pregnancy between black and white women and 73% of that between Hispanic and white women. Factors contributing to the disparity between black and white women included age, relationship status, respondent's mother's age at first birth, Federal Poverty Level, and insurance status. Between Hispanic and white women, these factors included age, U.S.-born status, education, and relationship status.

CONCLUSIONS

Given that the results showed factors at different levels of the social ecological model contribute to racial and ethnic disparities in unintended pregnancy, interventions that aim to reduce these disparities should target at-risk groups of women such as younger, unmarried, lower-income, less-educated, non-U.S. born women and uninsured or publicly insured women.

Gender Differences in Mental Health Outcomes before, during, and after the Great Recession

We examined gender differences in mental health outcomes during and post-recession versus pre-recession. We utilized 2005-2006, 2008-2009, and 2010-2011 data from the Medical Expenditure Panel Survey. Females had lower odds of depression diagnoses during and post-recession and better mental health during the recession, but higher odds of anxiety diagnoses post-recession. Males had lower odds of depression diagnoses and better mental health during and post-recession and lower Kessler 6 scores post-recession. We conducted stratified analyses, which confirmed that the aforementioned findings were consistent across the four different regions of the U.S., by employment status, income and health care utilization. Importantly, we found that the higher odds of anxiety diagnoses among females after the recession were mainly prominent among specific subgroups of females: those who lived in the Northeast or the Midwest, the unemployed, and those with low household income. Gender differences in mental health in association with the economic recession highlight the importance of policymakers taking these differences into consideration when designing economic and social policies to address economic downturns. Future research should examine the reasons behind the decreased depression diagnoses among both genders, and whether they signify decreased mental healthcare utilization or increased social support and more time for exercise and leisure activities.

Does depression and substance abuse co-morbidity affect socioeconomic status? Evidence from a prospective study of urban African Americans

Studies have established a graded association between mental health and socioeconomic status (SES). However, scarce research has examined the impact of substance use disorders (SUD) and depression comorbidity on SES. We use data from the Woodlawn Study, a longitudinal cohort study, which recruited a cohort of first graders from Chicago starting 1966-1967 (N=1242). Analyses focus on those interviewed in young adulthood and followed up through midlife. Regression analyses adjusting for childhood confounders showed that young adults with depression and SUD comorbidity had higher likelihood of having any periods of unemployment, higher likelihood of being unemployed for 3 or more months, and lower household income in midlife than those with neither disorder. Moreover, young adults with SUD without depression had higher odds of having any periods of unemployment and higher odds of being unemployed for 3 or more months than those with neither disorder. Findings point to the possibility of social selection where depression and SUD comorbidity contributes to a downward drift in SES. Clinical interventions that integrate the treatment of SUD and depression may be more effective at reducing socioeconomic disparities among minority populations.

A longitudinal analysis of maternal depressive symptoms and children's food consumption and weight outcomes

OBJECTIVE

Maternal depressive symptoms negatively impact mothers' parenting practices and children's development, but the evidence linking these symptoms to children's obesity is mixed.

DESIGN

We use a large sample to examine contemporaneous and lagged associations between maternal depressive symptoms and children's BMI, obesity and food consumption, controlling for background characteristics.

SETTING

Data from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), a longitudinal study of children from infancy through kindergarten in the USA, were collected at four waves from 2001 to 2007, when children were 9 months, 2 years, 4 years and 5½years of age, through surveys, child assessments and observations.

SUBJECTS

A sub-sample of children from the ECLS-B is used (n 6500).

RESULTS

Between 17 % and 19 % of mothers reported experiencing depressive symptoms; 17 % to 20 % of children were obese. Maternal depressive symptoms were associated with a small decrease in the likelihood her child was obese (0·8 percentage points) and with lower consumption of healthy foods. The duration of maternal depressive symptoms was associated with higher BMI (0·02 sd) among children whose parents lacked college degrees.

CONCLUSIONS

Results indicate that mothers' depressive symptoms have small associations with children's food consumption and obesity. Among children whose parents lack college degrees, persistent maternal depressive symptoms are associated with slightly higher child BMI. Findings highlight the need to control for depression in analyses of children's weight. Interventions that consider maternal depression early may be useful in promoting healthy weight outcomes and eating habits among children.

Decomposing differences in medical care access among cancer survivors by race and ethnicity

More research is needed to identify factors that explain why minority cancer survivors ages 18 to 64 are more likely to delay or forgo care when compared with whites. Data were merged from the 2000-2011 National Health Interview Survey to identify 12 125 adult survivors who delayed medical care. The Fairlie decomposition technique was applied to explore contributing factors that explain the differences. Compared with whites, Hispanics were more likely to delay care because of organizational barriers (odds ratio = 1.38; P < .05), and African Americans were more likely to delay medical care or treatment because of transportation barriers (odds ratio = 1.54; P < .001). The predicted probability of not receiving timely care because of each barrier was lowest among minorities. Age, insurance, perceived health, comorbidity, nativity, and year were significant factors that contributed to the disparities. Although expanded insurance coverage through the Affordable Care Act is expected to increase access, organizational factors and transportation play a major role.

Policymaking Under Uncertainty: Routine Screening for Intimate Partner Violence

Intimate partner violence (IPV) is a significant public health issue affecting around three million U.S. women during their lifetimes; this article provides guidance to policymakers on addressing IPV. In 2011, an Institute of Medicine panel recommended routine IPV screening for women and adolescents as part of comprehensive preventive care services, which is in conflict with the 2004 U.S. Preventive Services Task Force recommendations. The current evidence base for policymaking suffers weaknesses related to study design, which should be addressed in future research. Meanwhile, policymakers should consider available evidence in their settings, assess local needs, and make recommendations where appropriate.

Maternity leave duration and postpartum mental and physical health: implications for leave policies

This study examines the association of leave duration with depressive symptoms, mental health, physical health, and maternal symptoms in the first postpartum year, using a prospective cohort design. Eligible employed women, eighteen years or older, were interviewed in person at three Minnesota hospitals while hospitalized for childbirth in 2001. Telephone interviews were conducted at six weeks (N = 716), twelve weeks (N = 661), six months (N = 625), and twelve months (N = 575) after delivery. Depressive symptoms (Edinburgh Postnatal Depression Scale), mental and physical health (SF-12 Health Survey), and maternal childbirth-related symptoms were measured at each time period. Two-stage least squares analysis showed that the relationship between leave duration and postpartum depressive symptoms is U-shaped, with a minimum at six months. In the first postpartum year, an increase in leave duration is associated with a decrease in depressive symptoms until six months postpartum. Moreover, ordinary least squares analysis showed a marginally significant linear positive association between leave duration and physical health. Taking leave from work provides time for mothers to rest and recover from pregnancy and childbirth. Findings indicate that the current leave duration provided by the Family and Medical Leave Act, twelve weeks, may not be sufficient for mothers at risk for or experiencing postpartum depression.

Prenatal health behaviors and postpartum depression: is there an association?

Postpartum depression is a prevalent mental disorder; however, scarce research has examined its association with prenatal health behaviors. This study investigated the associations of cigarette smoking, caffeine intake, and vitamin intake during pregnancy with postpartum depressive symptoms at 8 weeks after childbirth. Using a prospective cohort study design, participants were recruited from the postpartum floor at a hospital for women and newborns located in a northeastern city, from 2005 through 2008. Eligible women who were at least 18 years old and spoke English were interviewed in person while hospitalized for childbirth (N = 662). A follow-up home interview was conducted at 8 weeks postpartum with a 79% response rate (N = 526). Hierarchical regression analyses showed that smoking cigarettes anytime during pregnancy and not taking prenatal vitamins in the first trimester were significantly associated with worse depressive symptoms (Edinburgh Postnatal Depression Scale). Moreover, having a colicky infant, an infant that refuses feedings, being stressed out by parental responsibility, and having difficulty balancing responsibilities were stressors associated with worse depressive symptoms. Primary health care providers should consider evaluating women for risk of postpartum depression during their first prenatal visit, identifying prenatal health behaviors such as smoking and taking prenatal vitamins.

Postpartum depressive symptoms and the combined load of paid and unpaid work: a longitudinal analysis

PURPOSE

To investigate the effects of total workload and other work-related factors on postpartum depression in the first 6 months after childbirth, utilizing a hybrid model of health and workforce participation.

METHODS

We utilized data from the Maternal Postpartum Health Study collected in 2001 from a prospective cohort of 817 employed women who delivered in three community hospitals in Minnesota. Interviewers collected data at enrollment and 5 weeks, 11 weeks, and 6 months after childbirth. The Edinburgh Postnatal Depression Scale measured postpartum depression. Independent variables included total workload (paid and unpaid work), job flexibility, supervisor and coworker support, available social support, job satisfaction, infant sleep problems, infant irritable temperament, and breastfeeding.

RESULTS

Total average daily workload increased from 14.4 h (6.8 h of paid work; 7.1% working at 5 weeks postpartum) to 15.0 h (7.9 h of paid work; 87% working at 6 months postpartum) over the 6 months. Fixed effects regression analyses showed worse depression scores were associated with higher total workload, lower job flexibility, lower social support, an infant with sleep problems, and breastfeeding.

CONCLUSIONS

Working mothers of reproductive years may find the study results valuable as they consider merging their work and parenting roles after childbirth. Future studies should examine the specific mechanisms through which total workload affects postpartum depressive symptoms.

Successful return to work for cancer survivors

This study investigated factors associated with successful return to work for cancer survivors in accordance with the Americans with Disabilities Act. A focus group was held with seven female cancer survivors. Participants discussed return-to-work issues following a cancer diagnosis. Factors such as coworker support and job flexibility improved their experiences, whereas coworker and supervisor ignorance about cancer and lack of support made returning to work more stressful. Participants discussed personal, environmental, and cancer-related factors that influenced their experiences with returning to work following a cancer diagnosis. Knowledge of factors that support employees helps occupational health nurses ease their transition, and may improve quality of life for employees. Physicians and health care provider teams may play a critical role in the employees' positive evaluation of their recovery process. This pilot study serves as a basis for a larger, population-based study.

Experimental autoimmune cystitis: further characterization and serum autoantibodies

Previously, we described an animal model for interstitial cystitis (IC), experimental autoimmune cystitis (EAC) [Luber-Narod et al. Urol Res 24:367]. Further characterization of animals with EAC indicates that peak and mean urinary frequency are elevated compared with sham-injected controls and that the disease progresses with at least two cycles of exacerbations and remissions. We had shown evidence suggesting EAC to be autoimmune in nature. In this paper, we identify serum autoantibodies from 9/10 EAC animals which bind to a protein specific to rat bladder with a relative molecular weight of 12-kDa. Such autoantibodies are absent in 12/13 normal and sham-injected animals as well as animals which fail to develop EAC despite disease induction. These findings suggest that EAC is a reproducible model of cyclical increases of urinary frequency, and that a 12-kDa antigen is the target of autoantibodies which correlate with those elevations. Identification of this target antigen may explain the pathogenesis of increased urinary frequency in these animals and potentially in IC as well.

Sulfone syndrome in a patient receiving steroids for pemphigus

A male patient who was being treated with oral prednisone for erosive mucocutaneous pemphigus lesions developed fever, jaundice, a rash, and anemia within 2 wk of starting dapsone therapy. These signs are typical of the sulfone syndrome, which is a potentially fatal condition due to dapsone hypersensitivity. The incidence of sulfone syndrome is increasing in frequency but has not previously been reported in pemphigus. This patient developed the syndrome early and while on oral steroids, which are sometimes used as a treatment for the sulfone syndrome, and without any evidence of a hypersensitivity reaction. Physicians should be aware of the potentially fatal sulfone syndrome in patients who are on dapsone therapy and who have abnormal liver tests, fever, and a rash.

Remissions of mammary adenocarcinoma in hypothyroid mice given 5-fluorouracil and chloroquine phosphate

In two separate experiments, treatment of C3H/He mice bearing transplantable mammary adenocarcinomas (C3HBA) with a regimen of 6-propylthiouracil (PTUra) and 5-fluorouracil (FUra) plus chloroquine phosphate (CP) resulted in complete remissions of 77 and 65%, respectively. Treatment with PTUra alone resulted in 41% remissions in experiment 1 and 35% remissions in experiment 2. None of the nontreated control mice in either experiment had spontaneous remissions, and all controls died in each experiment. The principal effect was apparently due to the treatment with PTUra, inasmuch as most of the tumors disappeared during the 21-day treatment period. This observation indicated that the proper timing of the thyroid treatment with PTUra was crucial to achieve the best results. The combined FUra+CP regimen augmented the effects of the thyroid treatment and resulted in an increase in remissions.

Modification of the graft-versus-host syndrome by anti-lymphocyte serum treatment of the host

The effect of administering anti-lymphocyte serum (ALS) to the F₁ hybrid recipient at various time intervals before and after the injection of parental donor cells has been investigated. The graft-versus-host (GVH) response can be completely inhibited by a single ALS injection given a short while before the injection of parental cells. ALS injected after the injection of donor cells fails to influence the GVH response.

It is considered that these studies confirm the view that ALS acts mainly on circulating lymphocytes and that a single ALS injection does not influence lymphocytes resident in spleen and lymph nodes.