Meredith L. Rowe

Different Epstein-Barr virus-B cell interactions in phenotypically distinct clones of a Burkitt's lymphoma cell line.

Epstein-Barr virus (EBV)-positive Burkitts lymphoma (BL) biopsy cells and early passage BL cell lines have been reported as showing an unusual type of virus-cell interaction; at least two EBV latent proteins appear not to be expressed. Serial passage of such lines is often accompanied by a broadening of virus latent gene expression and a corresponding change in the cell surface/growth phenotype towards that shown by in vitro transformed lymphoblastoid cell lines (LCLs). The sequence of events, both viral and cellular, involved in this transition needs to be defined properly. In the present work, phenotypically distinct cell clones have been derived from early passage cultures of a BL cell line in phenotypic transition, thereby giving access to relatively stable cell populations through which the different EBV-B cell interactions within the parental line can be studied. Clones retaining the original BL biopsy cell phenotype (CD10/CD77-positive, activation antigen/adhesion molecule-negative) expressed the virus-encoded nuclear antigen EBNA 1 but not any of the other known latent proteins, EBNAs 2, 3a, 3b, 3c, -LP and latent membrane protein (LMP). Other clones which had developed an LCL-like phenotype (CD10/CD77-negative, activation antigen/adhesion molecule-positive) now expressed all the above latent proteins and also contained significant numbers of cells in lytic cycle. Phenotypic change occurring within the parental BL cell line itself was initiated in a small subpopulation of cells in which the virus-encoded proteins EBNA 2 and LMP were transiently induced to an unusually high level of expression; this was accompanied by the first detectable changes in cell surface phenotype, namely the increase of cellular adhesion molecules. Some control over EBNA 2/LMP expression then appeared to be re-imposed since the presumed clonal descendents of these cells stably expressed EBNA 2 and LMP at much reduced levels typical of those seen in conventional LCLs.

Child-Directed Speech: Relation to Socioeconomic Status, Knowledge of Child Development and Child Vocabulary Skill.

This study sought to determine why American parents from different socioeconomic backgrounds communicate in different ways with their children. Forty-seven parent-child dyads were videotaped engaging in naturalistic interactions in the home for ninety minutes at child age 2;6. Transcripts of these interactions provided measures of child-directed speech. Childrens vocabulary comprehension skills were measured using the Peabody Picture Vocabulary Test at 2;6 and one year later at 3;6. Results indicate that: (I) child-directed speech with toddlers aged 2;6 predicts child vocabulary skill one year later, controlling for earlier toddler vocabulary skill; (2) child-directed speech relates to socioeconomic status as measured by income and education; and (3) the relation between socioeconomic status and child-directed speech is mediated by parental knowledge of child development. Potential mechanisms through which parental knowledge influences communicative behavior are discussed.

Differences in Early Gesture Explain SES Disparities in Child Vocabulary Size at School Entry

Children from low–socioeconomic status (SES) families, on average, arrive at school with smaller vocabularies than children from high-SES families. In an effort to identify precursors to, and possible remedies for, this inequality, we videotaped 50 children from families with a range of different SES interacting with parents at 14 months and assessed their vocabulary skills at 54 months. We found that children from high-SES families frequently used gesture to communicate at 14 months, a relation that was explained by parent gesture use (with speech controlled). In turn, the fact that children from high-SES families have large vocabularies at 54 months was explained by childrens gesture use at 14 months. Thus, differences in early gesture help to explain the disparities in vocabulary that children bring with them to school.

A longitudinal investigation of the role of quantity and quality of child-directed speech in vocabulary development

Quantity and quality of caregiver input was examined longitudinally in a sample of 50 parent-child dyads to determine which aspects of input contribute most to childrens vocabulary skill across early development. Measures of input gleaned from parent-child interactions at child ages 18, 30, and 42months were examined in relation to childrens vocabulary skill on a standardized measure 1year later (e.g., 30, 42, and 54months). Results show that controlling for socioeconomic status, input quantity, and childrens previous vocabulary skill; using a diverse and sophisticated vocabulary with toddlers; and using decontextualized language (e.g., narrative) with preschoolers explains additional variation in later vocabulary ability. The differential effects of various aspects of the communicative environment at several points in early vocabulary development are discussed.

Early gesture selectively predicts later language learning

The gestures children produce predict the early stages of spoken language development. Here we ask whether gesture is a global predictor of language learning, or whether particular gestures predict particular language outcomes. We observed 52 children interacting with their caregivers at home, and found that gesture use at 18 months selectively predicted lexical versus syntactic skills at 42 months, even with early child speech controlled. Specifically, number of different meanings conveyed in gesture at 18 months predicted vocabulary at 42 months, but number of gesture+speech combinations did not. In contrast, number of gesture+speech combinations, particularly those conveying sentence-like ideas, produced at 18 months predicted sentence complexity at 42 months, but meanings conveyed in gesture did not. We can thus predict particular milestones in vocabulary and sentence complexity at age by watching how children move their hands two years earlier.

The association of an HPV16 oncogene variant with HLA-B7 has implications for vaccine design in cervical cancer.

HLA-restricted cytotoxic T-lymphocyte (CTL) recognition of human papillomavirus (HPV) oncogene products may be important in the control of the HPV infections associated with the development of cervical cancer. We have identified, in HLA-B7 individuals, a consistent variation in the HPV16 E6 oncoprotein sequence, which alters an HLA-B7 peptide binding epitope in a way likely to influence immune recognition by CTLs. These results illustrate a biologically relevant mechanism for escape from immune surveillance of HPV16 in HLA-B7 individuals. Thus, both HLA type and HPV16 strain variation need to be considered in the screening of at-risk individuals and for the rational design of anti-HPV vaccines.

Learning words by hand: Gesture’s role in predicting vocabulary development

Children vary widely in how quickly their vocabularies grow. Can looking at early gesture use in children and parents help us predict this variability? We videotaped 53 English-speaking parent-child dyads in their homes during their daily activities for 90-minutes every four months between child age 14 and 34 months. At 42 months, children were given the Peabody Picture Vocabulary Test (PPVT). We found that child gesture use at 14 months was a significant predictor of vocabulary size at 42 months, above and beyond the effects of parent and child word use at 14 months. Parent gesture use at 14 months was not directly related to vocabulary development, but did relate to child gesture use at 14 months which, in turn, predicted child vocabulary. These relations hold even when background factors such as socio-economic status are controlled. The findings underscore the importance of examining early gesture when predicting child vocabulary development.

The Pace of Vocabulary Growth Helps Predict Later Vocabulary Skill.

Children vary widely in the rate at which they acquire words--some start slow and speed up, others start fast and continue at a steady pace. Do early developmental variations of this sort help predict vocabulary skill just prior to kindergarten entry? This longitudinal study starts by examining important predictors (socioeconomic status [SES], parent input, child gesture) of vocabulary growth between 14 and 46 months (n = 62) and then uses growth estimates to predict childrens vocabulary at 54 months. Velocity and acceleration in vocabulary development at 30 months predicted later vocabulary, particularly for children from low-SES backgrounds. Understanding the pace of early vocabulary growth thus improves our ability to predict school readiness and may help identify children at risk for starting behind.

The Epstein—Barr virus carrier state: dominance of a single growth-transforming isolate in the blood and in the oropharynx of healthy virus carriers

Epstein-Barr virus (EBV) isolates can be broadly classified as type 1 or type 2 on the basis of allelic polymorphism of the virus-encoded nuclear antigens EBNAs 2, 3a, 3b and 3c, and individually identified based on Mr values of their EBNA proteins (EBNA type). Here we have used this natural heterogeneity amongst isolates to re-examine the question of EBV persistence in vivo, asking in particular whether virus carriage in oropharyngeal epithelium and/or in B lymphoid tissues involves infection with a single or with multiple virus strains. Firstly, 76 healthy virus carriers were classified into serotype groups on the basis of preferential antibody reactivity to type 1 EBNAs (serotype 1) or to type 2 EBNAs (serotype 2); 60 of the 76 donors were serotype 1, four of the 76 donors were serotype 2 and 12 of the 76 donors were anti-EBNA 2, 3a, 3b, 3c antibody-negative and therefore could not be serotyped. Representative donors from each group were then selected for virus isolations from blood (by spontaneous in vitro transformation) and from throat washings (by cord blood cell transformation). All 13 serotype 1 donors tested and six of seven non-serotypeable donors gave a type 1 virus isolate, whereas all four serotype 2 donors and one of the seven non-serotypeable donors gave a type 2 isolate. Multiple transforming virus isolates from any one donor, whether from blood or throat washings, were all of the one strain characteristic of that particular donor; sequential isolations showed retention of the same strain over several years. Finally, throat washing samples from these same donors were examined for amplifiable EBV DNA in the polymerase chain reaction using EBV type-specific oligonucleotide primers and probes derived from the polymorphic EBNA 2 and EBNA 3c loci. The results were consistent with earlier virus isolation studies, each individual donor showing amplification either of type 1 or type 2 sequences. We conclude that multiple EBV infections must occur rarely, if at all, in healthy virus carriers; EBV persistence in vivo is characterized by dominance of a single transforming virus strain.

Maternal literacy and health behavior: a Nepalese case study

This article addresses the question of whether literacy could be mediating the relationships of schooling to maternal health behavior in populations undergoing demographic transition. Recent studies in which literacy was directly assessed suggest a literacy pathway to demographic change. The literacy skills of 167 urban and rural mothers of school-aged children in Lalitpur District of the Kathmandu Valley of Nepal were assessed by tests of reading comprehension, academic language proficiency, health media skills and health narrative skill, as part of studies in the urban and rural communities that included a maternal interview and ethnographic fieldwork on the contexts of family life, health care and female schooling. Regression analysis of the data indicates the retention of literacy skills in adulthood and their influence on health behavior; ethnographic evidence shows that selective bias in school attainment does not account for the results. Further direct assessment studies are recommended.