PDDL2.1: An Extension to PDDL for Expressing Temporal Planning Domains

In recent years research in the planning community has moved increasingly toward s application of planners to realistic problems involving both time and many typ es of resources. For example, interest in planning demonstrated by the space res earch community has inspired work in observation scheduling, planetary rover ex ploration and spacecraft control domains. Other temporal and resource-intensive domains including logistics planning, plant control and manufacturing have also helped to focus the community on the modelling and reasoning issues that must be confronted to make planning technology meet the challenges of application. The International Planning Competitions have acted as an important motivating fo rce behind the progress that has been made in planning since 1998. The third com petition (held in 2002) set the planning community the challenge of handling tim e and numeric resources. This necessitated the development of a modelling langua ge capable of expressing temporal and numeric properties of planning domains. In this paper we describe the language, PDDL2.1, that was used in the competition. We describe the syntax of the language, its formal semantics and the validation of concurrent plans. We observe that PDDL2.1 has considerable modelling power --- exceeding the capabilities of current planning technology --- and presents a number of important challenges to the research community.

A Polycomb-group gene regulates homeotic gene expression in Arabidopsis

Cell fate is determined when the commitment of cells to a particular fate is autonomously maintained, irrespective of their environment. In Drosophila, fate determination is maintained through the action of the Polycomb-group and trithorax-group genes, which are required so that states of homeotic gene activity are inherited through cell division. It is shown here that the CURLY LEAF gene of Arabidopsis is necessary for stable repression of a floral homeotic gene and encodes a protein with homology to the product of the Polycomb-group gene Enhancer of zeste. We suggest that Polycomb-group genes have a similar role in fate determination in plants and animals.

Effects of Social Needs Screening and In-Person Service Navigation on Child Health: A Randomized Clinical Trial

IMPORTANCE

Social determinants of health shape both children's immediate health and their lifetime risk for disease. Increasingly, pediatric health care organizations are intervening to address family social adversity. However, little evidence is available on the effectiveness of related interventions.

OBJECTIVE

To evaluate the effects of social needs screening and in-person resource navigation services on social needs and child health.

DESIGN, SETTING, AND PARTICIPANTS

Patients were randomized to intervention or active control conditions by the day of the week. Primary outcomes observed at 4 months after enrollment included caregivers' reports of social needs and child health status. Recruitment occurred between October 13, 2013, and August 27, 2015, in pediatric primary and urgent care clinics in 2 safety-net hospitals. Participants were English-speaking or Spanish-speaking caregivers accompanying minor children to nonacute medical visits.

INTERVENTIONS

After standardized screening, caregivers either received written information on relevant community services (active control) or received in-person help to access services with follow-up telephone calls for further assistance if needed (navigation intervention).

MAIN OUTCOMES AND MEASURES

Change in reported social needs and in caregiver assessment of child's overall health reported 4 months later.

RESULTS

Among 1809 patients enrolled in the study, evenly split between the 2 sites, 31.6% (n = 572) were enrolled in a primary care clinic and 68.4% (n = 1237) were enrolled in an urgent care setting. The children were primarily Hispanic white individuals (50.9% [n = 921]) and non-Hispanic black individuals (26.2% [n = 473]) and had a mean (SD) age of 5.1 (4.8) years; 50.5% (n = 913) were female. The reported number of social needs at baseline ranged from 0 to 11 of 14 total possible items, with a mean (SD) of 2.7 (2.2). At 4 months after enrollment, the number of social needs reported by the intervention arm decreased more than that reported by the control arm, with a mean (SE) change of -0.39 (0.13) vs 0.22 (0.13) (P < .001). In addition, caregivers in the intervention arm reported significantly greater improvement in their child's health, with a mean (SE) change of -0.36 (0.05) vs -0.12 (0.05) (P < .001).

CONCLUSIONS AND RELEVANCE

To our knowledge, this investigation is the first randomized clinical trial to evaluate health outcomes of a pediatric social needs navigation program. Compared with an active control at 4 months after enrollment, the intervention significantly decreased families' reports of social needs and significantly improved children's overall health status as reported by caregivers. These findings support the feasibility and potential effect of addressing social needs in pediatric health care settings.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01939704.

A seven-transmembrane domain receptor involved in fusion and entry of T-cell-tropic human immunodeficiency virus type 1 strains

Entry of human immunodeficiency virus type 1 (HIV-1) into cells requires binding to CD4 and fusion with a cellular membrane. Fusion does not occur in most nonhuman cells even when they express human CD4, indicating that one or more human accessory factors are required for virus infection. Recently, a seven-transmembrane domain protein has been shown to serve as an accessory factor for T-cell-tropic (T-tropic) HIV-1 isolates (Y. Feng, C. C. Broder, P. E. Kennedy, and E. A. Berger, Science 272:872-877, 1996). Here we show that expression of this glycoprotein, termed fusin, in murine, feline, simian, and quail cell lines, in conjunction with human CD4, rendered these cells fully permissive for HIV-1 envelope glycoprotein (Env)-mediated membrane fusion. Expression of CD4 or fusin alone did not permit fusion. In addition, introduction of fusin and CD4 into a human cell line, U87MG, that is resistant to HIV-1 induced syncytium formation and to infection by HIV-1 when expressing CD4 alone made this cell line permissive for Env-mediated cell-cell fusion. Fusion was observed only with T-tropic Env proteins. Macrophage-tropic (M-tropic) Env proteins from the SF162, ADA, and Ba-L HIV-1 strains did not fuse with cells expressing fusin and CD4, suggesting that M-tropic viruses utilize an accessory molecule other than fusin. Finally, coexpression of fusin and CD4 made both a murine and feline cell line susceptible to virus infection by T-tropic, but not M-tropic, HIV-1 strains.

ACAULIS5, an Arabidopsis gene required for stem elongation, encodes a spermine synthase

Polyamines have been implicated in a wide range of biological processes, including growth and development in bacteria and animals, but their function in higher plants is unclear. Here we show that the Arabidopsis: ACAULIS5 (ACL5) gene, whose inactivation causes a defect in the elongation of stem internodes by reducing cell expansion, encodes a protein that shares sequence similarity with the polyamine biosynthetic enzymes spermidine synthase and spermine synthase. Expression of the recombinant ACL5 protein in Escherichia coli showed that ACL5 possesses spermine synthase activity. Restoration of the acl5 mutant phenotype by somatic reversion of a transposon-induced allele suggests a non-cell-autonomous function for the ACL5 gene product. We also found that expression of the ACL5 cDNA under the control of a heat shock gene promoter in acl5 mutant plants restores the phenotype in a heat shock-dependent manner. The results of the experiments showed that polyamines play an essential role in promotion of internode elongation through cell expansion in Arabidopsis: We discuss the relationships to plant growth regulators such as auxin and gibberellins that have related functions.

Native oligomeric human immunodeficiency virus type 1 envelope glycoprotein elicits diverse monoclonal antibody reactivities

We synthesized and purified a recombinant human immunodeficiency virus type 1 (HIV-1) envelope (Env) glycoprotein, lacking the gp120/gp41 cleavage site as well as the transmembrane domain, that is secreted principally as a stable oligomer. Mice were immunized with separated monomeric and oligomeric HIV-1 Env glycoproteins to analyze the repertoire of antibody responses to the tertiary and quaternary structure of the protein. Hybridomas were generated and assayed for reactivity by immunoprecipitation of nondenatured Env protein. A total of 138 monoclonal antibodies (MAbs) were generated and cloned, 123 of which were derived from seven animals immunized with oligomeric Env. Within this group, a significant response was obtained against the gp41 ectodomain; 49 MAbs recognized epitopes in gp41, 82% of which were conformational. The influence of conformation on gp120 antigenicity was less pronounced, with 40% of the anti-gp120 MAbs binding to conformational epitopes, many of which blocked CD4 binding. Surprisingly, less than 7% of the MAbs derived from mice immunized with oligomeric Env recognized the V3 loop. In addition, MAbs to linear epitopes in the C-terminal domain of gp120 were not obtained, suggesting that this region of the protein may be partially masked in the oligomeric molecule. A total of 15 MAbs were obtained from two mice immunized with monomeric Env. Nearly half of these recognized the V3 loop, suggesting that this region may be a less predominant epitope in the context of oligomeric Env than in monomeric protein. Thus, immunization with oligomeric Env generates a large proportion of antibodies to conformational epitopes in both gp120 and gp41, many of which may be absent from monomeric Env.

A randomized trial on screening for social determinants of health: the iScreen study

BACKGROUND

There is growing interest in clinical screening for pediatric social determinants of health, but little evidence on formats that maximize disclosure rates on a wide range of potentially sensitive topics. We designed a study to examine disclosure rates and hypothesized that there would be no difference in disclosure rates on face-to-face versus electronic screening formats for items other than highly sensitive items.

METHODS

We conducted a randomized trial of electronic versus face-to-face social screening formats in a pediatric emergency department. Consenting English-speaking and Spanish-speaking adult caregivers familiar with the presenting child's household were randomized to social screening via tablet computer (with option for audio assist) versus a face-to-face interview conducted by a fully bilingual/bicultural researcher.

RESULTS

Almost all caregivers (96.8%) reported at least 1 social need, but rates of reporting on the more sensitive issues (household violence and substance abuse) were significantly higher in electronic format, and disclosure was marginally higher in electronic format for financial insecurity and neighborhood and school safety. There was a significant difference in the proportion of social needs items with higher endorsement in the computer-based group (70%) than the face-to-face group (30%).

CONCLUSIONS

Pediatric clinical sites interested in incorporating caregiver-reported socioeconomic, environmental, and behavioral needs screening should consider electronic screening when feasible, particularly when assessing sensitive topics such as child safety and household member substance use.

Localization and synthesis of an antigenic determinant of herpes simplex virus glycoprotein D that stimulates the production of neutralizing antibody

An antigenic determinant capable of inducing type-common herpes simplex virus (HSV)-neutralizing antibodies has been located on glycoprotein D (gD) of HSV type 1 (HSV-1). A peptide of 16 amino acids corresponding to residues 8 to 23 of the mature glycoprotein (residues 33 to 48 of the predicted gD-1 sequence) was synthesized. This peptide reacted with an anti-gD monoclonal antibody (group VII) previously shown to neutralize the infectivity of HSV-1 and HSV-2. The peptide was also recognized by polyclonal antibodies prepared against purified gD-1 but was less reactive with anti-gD-2 sera. Sera from animals immunized with the synthetic peptide reacted with native gD and neutralized both HSV-1 and HSV-2.

A Dissociation insertion causes a semidominant mutation that increases expression of TINY, an Arabidopsis gene related to APETALA2

A novel transposon-tagging strategy designed to recover dominant gain-of-function alleles was performed with Arabidopsis by using a Dissociation element with a cauliflower mosaic virus 35S promoter transcribing outward over one terminus. Lines containing transposed copies of this transposon were screened for mutants, and a semidominant mutation affecting plant height, hypocotyl elongation, and fertility was recovered. The pleiotropic effects of this mutation appear to result from a general reduction in cell expansion, and some of the effects are similar to those caused by supplying exogenous ethylene or cytokinin to wild-type seedlings. In addition, the arrangement of cells in some organs such as the etiolated hypocotyl, is disorganized. The mutation was called tiny, and the affected gene was cloned by first using transposon sequences to isolate the mutant allele. The predicted protein product of the TINY gene shows strong homology with the DNA binding domain of a recently identified class of plant transcription factors. This domain, called the APETALA2 domain, was initially identified as a duplicated region within the APETALA2 gene of Arabidopsis and then as a conserved region between APETALA2 and the ethylene responsive element binding proteins of tobacco. In the mutant allele, the Dissociation element is inserted in the untranslated leader of the TINY gene, 36 bp from the ATG, and the mutant contains a novel transcript that initiates from the cauliflower mosaic virus 35S promoter within the transposon. This transcript is present in greater abundance than the wild-type TINY transcript; therefore, the semidominant tiny mutation most likely results from increased, or ectopic, expression of the gene.

Localization of epitopes of herpes simplex virus type 1 glycoprotein D

We previously defined eight groups of monoclonal antibodies which react with distinct epitopes of herpes simplex virus glycoprotein D (gD). One of these, group VII antibody, was shown to react with a type-common continuous epitope within residues 11 to 19 of the mature glycoprotein (residues 36 to 44 of the predicted sequence of gD). In the current investigation, we have localized the sites of binding of two additional antibody groups which recognize continuous epitopes of gD. The use of truncated forms of gD as well as computer predictions of secondary structure and hydrophilicity were instrumental in locating these epitopes and choosing synthetic peptides to mimic their reactivity. Group II antibodies, which are type common, react with an epitope within residues 268 to 287 of the mature glycoprotein (residues 293 to 312 of the predicted sequence). Group V antibodies, which are gD-1 specific, react with an epitope within residues 340 to 356 of the mature protein (residues 365 to 381 of the predicted sequence). Four additional groups of monoclonal antibodies appear to react with discontinuous epitopes of gD-1, since the reactivity of these antibodies was lost when the glycoprotein was denatured by reduction and alkylation. Truncated forms of gD were used to localize these four epitopes to the first 260 amino acids of the mature protein. Competition experiments were used to assess the relative positions of binding of various pairs of monoclonal antibodies. In several cases, when one antibody was bound, there was no interference with the binding of an antibody from another group, indicating that the epitopes were distinct. However, in other cases, there was competition, indicating that these epitopes might share some common amino acids.

Perception of teratogenic risk by pregnant women exposed to drugs and chemicals during the first trimester

We assessed the perception of teratogenic risk by 80 women attending an antenatal consultation service for drug, chemical, and radiation exposure. Women exposed to agents not known to be teratogenic assigned themselves a risk of 24% +/- 2.8% for major malformation before the relevant medical literature was delivered to them and 14.5% +/- 3% thereafter. These women accurately estimated the risk for major malformation in the general population (5.6% +/- 1.3%). The tendency to terminate pregnancy when exposed to a nonteratogen significantly decreased after the consultation. Eleven patients exposed to drugs known to be teratogenic assigned a risk of 36.2% +/- 11.7% before the interview and did not change their perception thereafter (36.7% +/- 15.8%). Similarly, their tendency to continue or terminate pregnancy did not change; three of them eventually chose to terminate the pregnancy. Advising women about their teratogenic risk early in pregnancy may prevent unjustified termination of many pregnancies and may help to inform women exposed to proven teratogens about the known risk.

Antigenic implications of human immunodeficiency virus type 1 envelope quaternary structure: oligomer-specific and -sensitive monoclonal antibodies

A majority of monoclonal antibodies (mAbs) raised against soluble oligomeric human immunodeficiency virus type 1 isolate IIIB (HIV-1IIIB) envelope (env) glycoprotein reacted with conformational epitopes within the gp120 or gp41 subunits. Of 35 mAbs directed against gp41, 21 preferentially reacted with oligomeric env. A subset of these mAbs reacted only with env oligomers (oligomer-specific mAbs). In contrast, only 1 of 27 mAbs directed against the gp120 subunit reacted more strongly with env oligomers than with monomers, and none were oligomer-specific. However, 50% of anti-gp120 mAbs preferentially recognized monomeric env, suggesting that some epitopes in gp120 are partially masked or altered by intersubunit contacts in the native env oligomer. Two mAbs to oligomer-dependent epitopes in gp41 neutralized HIV-1IIIB and HIV-1SF2, and binding of these mAbs to env was blocked by preincubation with HIV-1-positive human serum. Thus, immunization with soluble, oligomeric env elicits antibodies to conserved, conformational epitopes including a newly defined class of neutralizing antibodies that bind to oligomer-specific epitopes in gp41, and may also minimize the production of antibodies that preferentially react with monomeric env protein.

Glycoprotein D protects mice against lethal challenge with herpes simplex virus types 1 and 2

Glycoprotein D is a virion envelope component of herpes simplex virus types 1 and 2. Sets of mice were immunized with purified gD-1 or gD-2 and were challenged with a lethal dose of herpes simple virus, either type 1 or type 2. All or virtually all of the immunized mice survived challenge with either agent, whereas challenge of sham-immunized mice was almost always fatal. Serum samples taken before challenge contained gD-specific antibodies which had 50% neutralization titers ranging from 1:16 to 1:512 against homologous and heterologous virus types. We conclude that either gD-1 or gD-2 is a potential candidate for a subunit vaccine against herpetic infections.

Quintupling Inhaled Glucocorticoids to Prevent Childhood Asthma Exacerbations

BACKGROUND

Asthma exacerbations occur frequently despite the regular use of asthma-controller therapies, such as inhaled glucocorticoids. Clinicians commonly increase the doses of inhaled glucocorticoids at early signs of loss of asthma control. However, data on the safety and efficacy of this strategy in children are limited.

METHODS

We studied 254 children, 5 to 11 years of age, who had mild-to-moderate persistent asthma and had had at least one asthma exacerbation treated with systemic glucocorticoids in the previous year. Children were treated for 48 weeks with maintenance low-dose inhaled glucocorticoids (fluticasone propionate at a dose of 44 μg per inhalation, two inhalations twice daily) and were randomly assigned to either continue the same dose (low-dose group) or use a quintupled dose (high-dose group; fluticasone at a dose of 220 μg per inhalation, two inhalations twice daily) for 7 days at the early signs of loss of asthma control ("yellow zone"). Treatment was provided in a double-blind fashion. The primary outcome was the rate of severe asthma exacerbations treated with systemic glucocorticoids.

RESULTS

The rate of severe asthma exacerbations treated with systemic glucocorticoids did not differ significantly between groups (0.48 exacerbations per year in the high-dose group and 0.37 exacerbations per year in the low-dose group; relative rate, 1.3; 95% confidence interval, 0.8 to 2.1; P=0.30). The time to the first exacerbation, the rate of treatment failure, symptom scores, and albuterol use during yellow-zone episodes did not differ significantly between groups. The total glucocorticoid exposure was 16% higher in the high-dose group than in the low-dose group. The difference in linear growth between the high-dose group and the low-dose group was -0.23 cm per year (P=0.06).

CONCLUSIONS

In children with mild-to-moderate persistent asthma treated with daily inhaled glucocorticoids, quintupling the dose at the early signs of loss of asthma control did not reduce the rate of severe asthma exacerbations or improve other asthma outcomes and may be associated with diminished linear growth. (Funded by the National Heart, Lung, and Blood Institute; STICS ClinicalTrials.gov number, NCT02066129 .).

Purification of glycoprotein gD of herpes simplex virus types 1 and 2 by use of monoclonal antibody

Glycoproteins gD-1 and gD-2 of herpes simplex virus types 1 and 2, respectively, were purified on an immunoadsorbent consisting of the type-common monoclonal antibody HD-1 linked to Sepharose. Each glycoprotein was of sufficient purity, quantity, and biological activity to be used for immunological and biochemical studies. Each glycoprotein induced high titers of type-common monospecific neutralizing antibody in mice. Amino aicd analysis indicated that gD-1 and gD-2 had similar though not identical amino acid compositions.

Expression of herpes simplex virus type 1 glycoprotein D deletion mutants in mammalian cells

Glycoprotein D (gD) is a viron envelope component of herpes simplex virus types 1 and 2. We have previously defined seven monoclonal antibody (MAb) groups which recognize distinct epitopes on the mature gD-1 protein of 369 amino acids. MAb groups VII, II, and V recognize continuous epitopes at residues 11-19, 272-279, and 340-356, respectively. MAb groups I, III, IV, and VI recognize discontinuous epitopes. Recent studies have focused on epitopes I, III, and VI. Using truncated forms of gD generated by recombinant DNA methods and proteolysis, epitopes III, IV, and VI were located within amino acids 1-233. A portion of discontinuous epitope I was located in a region within residues 233-275. For this study, we used recombinant DNA methods to create mutations in the gD-1 gene and studied the effects of those mutations on gD as expressed in mammalian cells. Plasmid pRE4, containing the coding sequence of gD-1 and the Rous sarcoma virus long terminal repeat promoter, was transfected into mammalian cells. The expressed protein, gD-1-(pRE4), was identical in size and antigenic properties to gD-1 from infected cells. Six in-frame deletion mutations were subsequently constructed by using restriction enzymes to excise portions of the gD-1 gene. Plasmids carrying these mutated forms were transfected into cells, and the corresponding proteins were examined at 48 h posttransfection for antigenicity and glycosylation patterns. Three deletions of varying size were located downstream of residue 233. Analysis of these mutants showed that amino acids within the region 234-244 were critical for binding of DL11 (group I), but not for other MAb groups. Three other deletion mutants lost all ability to bind MAbs which recognize discontinuous epitopes. In addition, much of the gD expressed by these mutants was observed to migrate as high-molecular-weight aggregated forms in nondenaturing gels. Each of these mutations involved the loss of a cysteine residue, suggesting that disulfide linkages play an essential role in the formation of discontinuous epitopes. The extent of glycosylation of the mutant gD molecules accumulated at 48 h posttransfection suggested altered carbohydrate processing. In one case, there was evidence for increased O-linked glycosylation. Those proteins which had lost a cysteine residue as part of the deletion did not accumulate molecules processed beyond the high-mannose stage. The results suggest that carbohydrate processing during synthesis of gD is very sensitive to alterations in structure, particularly changes involving cysteine residues.

Development and implementation of a pediatric adverse childhood experiences (ACEs) and other determinants of health questionnaire in the pediatric medical home: A pilot study

Adverse Childhood Experiences (ACEs) are associated with poor health outcomes, underlining the significance of early identification and intervention. Currently, there is no validated tool to screen for ACEs exposure in childhood. To fill this gap, we designed and implemented a pediatric ACEs questionnaire in an urban pediatric Primary Care Clinic. Questionnaire items were selected and modified based on literature review of existing childhood adversity tools. Children twelve years and under were screened via caregiver report, using the developed instrument. Cognitive interviews were conducted with caregivers, health providers, and clinic staff to assess item interpretation, clarity, and English/Spanish language equivalency. Using a rapid cycle assessment, information gained from the interviews were used to iteratively change the instrument. Additional questions assessed acceptability of screening within primary care and preferences around administration. Twenty-eight (28) caregivers were administered the questionnaire. Cognitive interviews conducted among caregivers and among 16 health providers and clinic staff resulted in the changes in wording and addition of examples in the items to increase face validity. In the final instrument, no new items were added; however, two items were merged and one item was split into three separate items. While there was a high level of acceptability of the overall questionnaire, some caregivers reported discomfort with the sexual abuse, separation from caregiver, and community violence items. Preference for methods of administration were split between tablet and paper formats. The final Pediatric ACE and other Determinants of Health Questionnaire is a 17-item instrument with high face validity and acceptability for use within primary care settings. Further evaluation on the reliability and construct validity of the instrument is being conducted prior to wide implementation in pediatric practice.

Synthesis and processing of glycoproteins gD and gC of herpes simplex virus type 1

Herpes simplex virus type 1 (HSV-1) contains five glycoproteins, designated gA, gB, gC, gD, and gE. The present studies focused on the synthesis and processing of two of these, gC and gD. By using monoprecipitin antibody to gC, we demonstrated an antigenic and structural relationship between the precursor, pgC(110), and the product, gC(130). Tryptic peptide analysis showed that pgC and gC shared methionine peptides and that these molecules had the same fingerprint pattern as that of gC(130) extracted from the purified virion. These results suggested that post-translational processing of gC involved no major changes in methionine-containing tryptic peptides or in the cleavage sites required to generate those peptides. The syntheses of gC and gD were compared. We found that the glycoproteins were synthesized starting at different times in the infectious cycle; pgD was detected by 2 h postinfection, whereas pgC was first detected at 4 to 6 h postinfection. Both precursor molecules, pgC(110) and pgD(52), are basic glycopolypeptides, and in both cases processing involved changes in molecular weight and charge. These changes were detected by two-dimensional gel electrophoresis. Both glycoproteins exhibited heterogeneity, displayed as a series of spots (6 for gD and 15 to 20 for gC) of increasing negative charge and molecular weight. Neuraminidase treatment decreased the size, number, and acidic charge of the spots, suggesting that processing was due in part, but not entirely, to addition of sialic acid to pgD and pgC.

Electroosmotic Flows Created by Surface Defects in Capillary Electrophoresis

We compute the electroosmotic flow in nonuniformly charged planar and cylindrical capillaries for the limit of low-Reynolds-number flows and thin Debye layers. Analytical formulae for the velocity field are provided for the general case of an arbitrary surface inhomogeneity but we also focus on various specific defect geometries. Many important features can be obtained from the simple lubrication approximation. The pressure jump induced by the presence of such surface defects is calculated and the possible occurrence of recirculating flows is discussed, as are effects of the flow perturbations on dispersion in capillary electrophoresis. Copyright 1999 Academic Press.

Redesigning Health Care Practices to Address Childhood Poverty

Child poverty in the United States is widespread and has serious negative effects on the health and well-being of children throughout their life course. Child health providers are considering ways to redesign their practices in order to mitigate the negative effects of poverty on children and support the efforts of families to lift themselves out of poverty. To do so, practices need to adopt effective methods to identify poverty-related social determinants of health and provide effective interventions to address them. Identification of needs can be accomplished with a variety of established screening tools. Interventions may include resource directories, best maintained in collaboration with local/regional public health, community, and/or professional organizations; programs embedded in the practice (eg, Reach Out and Read, Healthy Steps for Young Children, Medical-Legal Partnership, Health Leads); and collaboration with home visiting programs. Changes to health care financing are needed to support the delivery of these enhanced services, and active advocacy by child health providers continues to be important in effecting change. We highlight the ongoing work of the Health Care Delivery Subcommittee of the Academic Pediatric Association Task Force on Child Poverty in defining the ways in which child health care practice can be adapted to improve the approach to addressing child poverty.

Effect of monoclonal antibodies on limited proteolysis of native glycoprotein gD of herpes simplex virus type 1

We examined the properties of 17 monoclonal antibodies to glycoprotein gD of herpes simplex type 1 (HSV-1) (gD-1) and HSV-2 (gD-2). The antibodies recognized eight separate determinants of gD, based on differences in radioimmuno-precipitation and neutralization assays. The determinants were distributed as follows: three were gD-1 specific, one was gD-2 specific, and four were type common. Several type-specific and type-common determinants appeared to be involved in neutralization. We developed a procedure for examining the effect that binding of monoclonal antibody has on proteolysis of native gD-1 by Staphylococcus aureus protease V8. We showed that several different patterns of protease V8 cleavage were obtained, depending on the monoclonal antibody used. The proteolysis patterns were generally consistent with the immunological groupings. With four groups of antibodies, we found that fragments of gD-1 remained bound to antibody after V8 treatment. A 38,000-dalton fragment remained bound to antibodies in three different groups of monoclonal antibodies. This fragment appeared to contain one type-common and two type-specific determinants. A 12,000-dalton fragment remained bound to antibodies belonging to one type-common group of monoclonal antibodies. Tryptic peptide analysis revealed that the 12,000-dalton fragment represented a portion of the 38,000-dalton fragment and was enriched in a type-common arginine tryptic peptide.

The maize transposable element system Ac/Ds as a mutagen in Arabidopsis: identification of an albino mutation induced by Ds insertion

A two-component transposon system based on the Ac element of maize was used as a mutagen in Arabidopsis thaliana. Transposition of a Ds element marked with a hygromycin-resistance gene was activated from four different locations in the Arabidopsis genome. The progeny of 201 plants carrying independent transposition events were screened for mutants with severe, visible phenotypes. Seven mutants were identified and four of them were analyzed genetically. Three mutations were shown to be very closely linked to a transposed copy of the element. Moreover, a mutation (alb3) causing an albino phenotype was conclusively shown to be caused by insertion of the Ds element: somatic and germinal reversion of the mutation occurred in the presence of the transposase gene but not in its absence, and in three revertants the Ds had excised from its position in the mutant line. The DNA adjacent to Ds in the mutant was isolated and it was demonstrated that revertants retained part of the 8-bp duplication caused by insertion of Ds. These experiments indicate that the Ac/Ds system can be used as an insertional mutagen in the heterologous host Arabidopsis, which will permit the isolation of genes from this species by transposon tagging.