Background Progressive maturation of growth plate chondrocytes drives long bone growth during endochondral ossification. Signals from the epidermal growth factor receptor (EGFR), and from bone morphogenetic protein‐2 (BMP2), are required for normal chondrocyte maturation. Here, we investigated cross‐talk between EGFR and BMP2 signals in developing and adult growth plates. Results Using in vivo mouse models of conditional cartilage‐targeted EGFR or BMP2 loss, we show that canonical BMP signal activation is increased in the hypertrophic chondrocytes of EGFR‐deficient growth plates; whereas EGFR signal activation is increased in the reserve, prehypertrophic and hypertrophic chondrocytes of BMP2‐deficient growth plates. EGFR‐deficient chondrocytes displayed increased BMP signal activation in vitro, accompanied by increased expression of IHH, COL10A1, and RUNX2. Hypertrophic differentiation and BMP signal activation were suppressed in normal chondrocyte cultures treated with the EGFR ligand betacellulin, effects that were partially blocked by simultaneous treatment with BMP2 or a chemical EGFR antagonist. Conclusions Cross‐talk between EGFR and BMP2 signals occurs during chondrocyte maturation. In the reserve and prehypertrophic zones, BMP2 signals unilaterally suppress EGFR activity; in the hypertrophic zone, EGFR and BMP2 signals repress each other. This cross‐talk may play a role in regulating chondrocyte maturation in developing and adult growth plates.

Purpose The readability and comprehensibility of Learner's Permit Knowledge Test practice questions and the relationship with test failure rates across states and the District of Columbia were examined. Method Failure rates were obtained from department representatives. Practice test questions were extracted from drivers' manuals and department websites and examined for readability using Flesch–Kincaid Grade Level and comprehensibility using Question Understanding Aid. The influence of readability and comprehensibility on test failure rates was explored. Results The average failure rate from reporting jurisdictions was 42.76%. In total, 11 out of 28 jurisdictions reported that test takers fail more than half the time, while 25 out of 28 reported that test takers fail at least a quarter of the time. While 33.09% of the variability in failure rates could be accounted for by syntactic complexity of the questions, 54.18% could be accounted for by the reading ease. Discussion With few exceptions, test failure rates are systematically high across the United States. The current findings suggest that these tests may be inappropriately biased against individuals with lower levels of literacy and language ability. Implications for test developers and clinicians are discussed.

Background Infants with congenital cytomegalovirus infection (cCMV) are at risk for neurodevelopmental impairment (NDI). Antiviral therapy has been shown to improve neurodevelopmental outcomes but is not recommended for all infected infants. There are currently no predictive markers for NDI in infants with cCMV. Our objective was to compare neonatal T cell differentiation and memory phenotypes in CMV-infected infants with and without subsequent NDI. Methods Blood samples were collected from infants with cCMV and age-matched healthy controls. Peripheral blood mononuclear cells were analyzed by flow cytometry for CD4 and CD8 T cells expressing CD28, CD57, PD, CD45RA/RO, and CCR7. Demographic and clinical data were collected. NDI was defined as Bayley III/IV testing below the average range in at least one domain in infants for whom this developmental testing was available or based on diagnosis by infectious disease physician or primary care provider. Outcomes for infants with follow-up at least 6 months of age were included. Infants with isolated speech delay associated with hearing loss were not considered to have NDI. Results Samples were analyzed from 18 infants (Table 1) at time of diagnosis (≤ 60 days of age) and 5 uninfected age-matched controls. The frequencies of CD8+ T cells expressing CD28low (differentiation), CD57+ (terminal differentiation/senescence), PD1hi (inhibitory or exhausted phenotype) and CD45RO± (memory) phenotypes were higher for the cCMV group without NDI compared to that with NDI (Figure 1). The cCMV group without NDI had lower proportions of naïve (CCR7+/CD45RA+) effector memory, TEM (CCR7-/CD45RA-), and effector memory RA, TEMRA (CCR7-/CD45RA+) CD8+ T cells than those with NDI (Figure 2). There was no difference in memory distribution or surface marker expression of CD4+ T cells. Table 1 Demographic and clinical characteristics of the infants with congenital cytomegalovirus infection (cCMV) with and without neurodevelopmental impairment (NI) and age-matched controls. Continuous variables are compared using the Mann Whitney U test and categorical variables with the Fischer’s Exact test. There were no significant differences between infants with and without NI. Figure 1.CD8+ T cell phenotypes in cCMV groups with and without Neurodevelopmental Impairment (NDI) Frequencies of CD8+ T cells lacking expression of CD28 (A), or expressing CD57 (B), PD-1 (C), or CD45RO (D) are shown at age ≤ 60 days. Infants with congenital CMV (cCMV) and normal neurodevelopmental outcome are shown in blue, infants with neurodevelopmental impairment are shown in red, and uninfected age-matched controls are shown in black. Data are shown as medians [interquartile range]. Groups were compared using the Mann Whitney U Test. Infants with no NDI had significantly higher frequencies of CD28- (p = 0.002), CD57+ (p = 0.001), PD-1+ (p = 0.01) and CD45RO+ (p = 0.01) CD8 T cells. * p ≤ 0.05; ** p ≤ 0.01. Figure 2.T cell memory subset distributions among cCMV groups and uninfected controls Proportions of CD4+ (A) and CD8+ (B) naïve (CCR7+/CD45RA+), central memory, TCM (CCR7+/CD45RA-), effector memory, TEM (CCR7-, CD45RA-), and effector memory RA, TEMRA (CCR7-/CD45RA+) T cells. Infants with congenital CMV (cCMV) and normal neurodevelopmental outcome are shown in blue, infants with neurodevelopmental impairment (NI) are shown in red while uninfected age-matched controls are shown in black and gray. Comparisons between T cell groups were made using the Mann Whitney U test. Infants with cCMV without NI had significantly fewer naïve (p = 0.0001), greater TEM (p = 0.0001), and TEMRA (p = 0.005) CD8+ T cells than those with NI. The distributions of CD4+ T cells were not significantly different. Conclusion In this small cohort of infants infected with CMV, these data suggest that a more differentiated memory CD8+ T cell phenotype in the neonatal period may correlate with normal neurodevelopmental outcomes. Disclosures Alexandra K. Medoro, MD, Merck: Grant/Research Support.

Congenital CMV (cCMV) infection can affect infants born to mothers with preconceptional seroimmunity. To prevent cCMV due to nonprimary maternal infection, vaccines eliciting responses exceeding natural immunity may be required. Anti-gM/gN antibodies have neutralizing capacity in-vitro and in animal models, but anti-gM/gN antibodies have not been characterized among seroimmune pregnant women. Paired maternal and infant cord sera from 92 CMV seropositive mothers and their full-term or preterm infants were tested for anti-gM/gN antibody titers in comparison with anti-gB titers and neutralizing activity. Anti-gM/gN titers were significantly lower than anti-gB titers for all groups and did not correlate with serum neutralizing capacity. Further study is needed to determine if higher anti-gM/gN antibody titers might enhance serum neutralizing capacity among seropositive adults.