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Biomedical subjects

J P Mayer

Publications and source records attributed to J P Mayer.

At least 19 recordsLinked to original sources
PubMed1999

Evaluation of a campaign to improve immunization in a rural headstart program.

This study evaluated an intervention to improve immunization rates in a high poverty, medically underserved rural area employing a pretest-posttest design. The intervention expanded immunization availability, established walk-in appointment policies, and introduced intensified parent education. Formative evaluation indicated specific messages with high salience to parents. As a result, the susceptibility and severity of childhood infectious disease, the outcome efficacy of vaccines, and methods to reduce barriers to immunization were emphasized in communications with parents. Data on DTP1-4, OPV1-3, and MMR were obtained from preschools, local health departments and private medical practices before (n = 567) and after the intervention (n = 331). Following adjustment for birth order and demographics, at post-intervention a significantly greater proportion of children received 6 of 8 vaccines on time. Effect sizes were large. For example, post MMR rates were at least 2X greater than pre rates. Time-series analysis of trend data on local newspaper coverage of child health topics suggested history was not a major threat to the internal validity of this pre-post only design. The findings indicate that comprehensive intervention, targeting improvements in the availability of pediatric care, health system policies and parent behavior, can improve immunization.

Attitude to Health↗
PubMed1998

A randomized trial of an intervention to prevent lawnmower injuries in children.

The U.S. Consumer Product Safety Commission reports about 60,000 emergency room visits for lawnmower injuries annually with 20% to children under 15 years. Employing a randomized pre-post control group design, the current study evaluated a 20-minute video intervention to increase parents' (n = 80) safety awareness and preventive actions. The setting was an outpatient clinic at a Children's Hospital. Differences favoring the intervention group were found for four of six behavior outcomes. For example, the proportion reporting never allowing children near operating mowers increased from half to two-thirds with no change among comparison group parents. In addition, significant increases in severity beliefs were found. The results provide formative support for the video intervention which possesses the key advantages of ease of use and constancy of message.

Accidents, Home↗
PubMed1998

Lanthionine macrocyclization by in situ activation of serine.

The present report details a straightforward, solid-phase approach to cyclolanthionine peptides. After stepwise assembly of the linear sequence and transformation of a single exposed serine to bromoalanine using P(Ph)3/CBr4, the detritilation of a cysteine side-chain sets the stage for a base-promoted macrocyclization. The entire procedure can be carried out in a solid-phase vessel using conventional 9-fluorenylmethyloxycarbonyl/tert-butyl-based chemistry and is amenable to automated format. The utility of this novel procedure is demonstrated by the synthesis of two previously reported lanthionine-containing cyclic peptides.

Alanine↗
PubMed1998

A Neu differentiation factor (NDF) domain essential for proliferation and alterations in morphology of colonic epithelial cells in vitro.

The Neu Differentiation Factors (NDFs, also termed "heregulins") are a family of proteins that were first isolated as ligands for the HER2 (ergB2, or p185neu) receptor protein tyrosine kinase. Here we show that NDF acts to stimulate the proliferation and alter the cellular morphology of colonic epithelial cells in culture. Dramatic NDF-induced changes in cellular morphology were noted in the colonic epithelial cell line, LIM 1215. In addition, the expression of specific cell proteins, such as carcinoembryonic antigen and integrin beta 4, was induced in LIM 1215 cells by NDF. These effects were more pronounced with the beta isoform than with the alpha isoform of NDF. The EGF-homology domain of NDF beta was sufficient to stimulate the proliferation and alteration in cell morphology. The use of chemically synthesized chimeric NDF alpha and NDF beta proteins enabled use to identify a region of seven amino acids in the EGF-homology domain of NDF beta that is required for both activities. These in vitro experiments suggest that NDF may act as a regulator of growth and differentiation of colonic epithelial cells in vivo.

Amino Acid Sequence↗
PubMed1997

In vitro assay and characterization of the farnesylation-dependent prelamin A endoprotease.

The 72-kDa nuclear lamina protein lamin A is synthesized as a 74-kDa farnesylated precursor. Conversion of this precursor to mature lamin A appears to be mediated by a specific endoprotease. Prior studies of overexpressed wild-type and mutant lamin A proteins in cultured cells have indicated that the precursor possesses the typical carboxyl-terminal S-farnesylated, cysteine methyl ester and that farnesylation is required for endoproteolysis to occur. In this report, we describe the synthesis of an S-farnesyl, cysteinyl methyl ester peptide corresponding to the carboxyl-terminal 18 amino acid residues of human prelamin A. This peptide acts as a substrate for the prelamin A endoprotease in vitro, with cleavage of the synthetic peptide at the expected site between Tyr657 and Leu658. Endoproteolytic cleavage requires the S-prenylated cysteine methyl ester and, in agreement with transfection studies, is more active with the farnesylated than geranylgeranylated cysteinyl substrate. N-Acetyl farnesyl methyl cysteine is shown to be a noncompetitive inhibitor of the enzyme. Taken together, these observations suggest that there is a specific farnesyl binding site on the enzyme which is not at the active site.

Amino Acid Sequence↗
PubMed1997

Typology of local health departments based on maternal and child health core functions.

A survey of Missouri local health departments (LHDs) was conducted to measure core public health functions within maternal and child health (MCH). Measurement was based on a prior key informant study that defined each core function as a set of specific MCH activities, programs, and services. The 59 items in the survey operationalized these activities and enabled the creation of summary scores for assessment, policy development, and assurance. Participation included 93 of the 112 Missouri LHDs (83%) in 1995. Reliability coefficients for the summary scores ranged from .83 to .92. Cluster analysis produced six types of LHDs with differing core function patterns. By matching efforts to improve core function practice to LHD type, more efficient use of capacity building resources may result.

Female↗
PubMed1997

Unintended childbearing, maternal beliefs, and delay of prenatal care.

BACKGROUND: Delay of prenatal care is an important risk for poor birth outcome, yet its association with maternal knowledge and beliefs remains insufficiently studied. This research examined the relationship of unintended childbearing and beliefs about the importance of prenatal care with initiation after the first trimester, adjusting for key sociodemographic determinants. METHODS: One hundred fifty-four Texas hospitals accounting for 80 percent of state births were asked to collect surveys from all women delivering infants during a one-week interval in 1986. Seventy-four percent of hospitals and 70 percent of women participated (n = 2032). No differences occurred between the sample and the population on rates of delayed care and low birthweight or maternal demographics. RESULTS: Since delayed prenatal care is more frequent among low-income women, analyses were limited to those below the 200 percent poverty level. After adjustment for maternal age, marital status, education, parity, race, and health insurance status employing logistic regression, unintended births were 1.6 times more likely to involve delayed care. Mothers who believed prenatal care was unimportant were 2.1 times more likely to delay care. These coefficients exceeded or about equaled those for the covariates. CONCLUSIONS: Preconception education about the value of prenatal care and family planning programs to prevent unintended pregnancies should be conducted together with efforts to overcome financial and structural barriers if progress toward national prenatal care objectives is to be achieved.

Adult↗
PubMed1996

Mature T cell reactivity altered by peptide agonist that induces positive selection.

Recent studies have investigated how defined peptides influence T cell development. Using a T cell receptor-transgenic beta2-microglobulin-deficient model, we have examined T cell maturation in fetal thymic organ cultures in the presence of various peptides containing single-alanine substitutions of the strong peptide agonist, p33. Cocultivation with the peptide A4Y, which contains an altered T cell contact residue, resulted in efficient positive selection. Several in vitro assays demonstrated that A4Y was a moderate agonist relative to p33. Although A4Y promoted positive selection over a wide concentration range, high doses of this peptide could not induce clonal deletion. Thymocytes maturing in the presence of A4Y were no longer able to respond to A4Y, but could proliferate against p33. These studies demonstrate that (a) peptides that induce efficient positive selection at high concentrations are not exclusively antagonists; (b) some agonists do not promote clonal deletion; (c) positive selection requires a unique T cell receptor-peptide-major histocompatibility complex interaction; and (d) interactions with selecting peptides during T cell ontogeny may define the functional reactivity of mature T cells.

Amino Acid Sequence↗
PubMed1995

Affinity and specificity requirements for the first Src homology 3 domain of the Crk proteins.

The specificity of SH3 domain complex formation plays an important role in determining signal transduction events. We have previously identified a highly specific interaction between the first CrkSH3 domain [CrkSH3(1)] and proline-rich sequences in the guanine nucleotide exchange factor C3G. A 10 amino acid peptide derived from the first proline-rich sequence (P3P4P5A6L7P8P9K10K11R12) bound with a Kd of 1.89 +/- 0.06 microM and fully retained the high affinity and unique selectivity for the CrkSH3(1) domain. Mutational analysis showed that P5, P8, L7 and K10 are critical for high affinity binding. A conservative mutation, K10R, significantly decreased the affinity for the CrkSH3(1) domain while increasing the affinity for Grb2. Comparative binding studies with the K10R and K10A mutant peptides to c-Crk and v-Crk further suggested that K10 binds via a charge-dependent and a charge-independent interaction to the RT loop of the CrkSH3(1) domain. Besides determining important structural features necessary for high affinity and specificity binding to the CrkSH3(1) domain, our results also demonstrate that a conservative mutation in a single amino acid can significantly alter the specificity of an SH3 binding peptide.

Adaptor Proteins, Signal Transducing↗
PubMed1994

Afamin is a new member of the albumin, alpha-fetoprotein, and vitamin D-binding protein gene family.

A novel human serum protein with a molecular mass of 87,000 daltons was purified to homogeneity and subjected to amino acid sequence analyses. These sequences were used to design oligonucleotide primers and to isolate a full-length cDNA. The amino acid sequence encoded by the cDNA shares strong similarity to albumin family members and shares the characteristic pattern of Cys residues observed in this family. In addition, the gene maps to chromosome 4 as do other members of the albumin gene family. Based upon these observations, we conclude that the 87,000-dalton protein, which we designate afamin (AFM), is the fourth member of the albumin family of proteins. Afamin cDNA was stably transfected into Chinese hamster ovary cells and recombinant protein (rAFM) was purified from conditioned medium. Both rAFM and AFM purified from human serum react with a polyclonal antibody that was raised against a synthetic peptide derived from the deduced amino acid sequence of AFM.

Albumins↗
PubMed1993

Requirement for CD8+ cells in T cell receptor peptide-induced clonal unresponsiveness.

T cell receptor (TCR) vaccination in rats prevents the development of experimental allergic encephalomyelitis (EAE), an animal model of multiple sclerosis. The mechanism of this potential immunotherapy was examined by vaccinating mice with an immunogenic peptide fragment of the variable region of the TCR V beta 8.2 gene. Another immunogen that usually induces an immune response mediated by V beta 8.2+ T cells was subsequently inhibited because specific clonal unresponsiveness (anergy) had been induced. Depletion of CD8+ cells before TCR peptide vaccination blocked such inhibition. Thus, the clonal anergy was dependent on CD8+ T cells, and such immunoregulatory T cells may participate in the normal course of EAE.

Animals↗
PubMed1993

A time series study of the impact of eligibility expansion on Medicaid financing of births.

In a major reform addressing declines in coverage over the prior decade, Congress in 1986 allowed states to expand Medicaid eligibility to all pregnant women in poverty. However, at the outset of the expansions uncertainty existed as to whether eligibility expansion alone would result in greater coverage without aggressive outreach designed to bring more low-income pregnant women into the program. Using interrupted time series methods, the analyses presented in this paper show a significant increase in Medicaid financing of deliveries in two states that expanded eligibility and also made efforts to simplify application procedures and publicize the expansions. Policy implications of the findings are discussed.

Birth Rate↗
PubMed1993

Consumption of fruits and vegetables in Missouri.

High consumption of fruits and vegetables has been linked with a reduced risk of several important chronic diseases. The authors utilized telephone survey techniques to assess the level of fruit and vegetable consumption among adult Missouri residents. Only 28% of respondents reported consumption of five servings of fruits and vegetables per day. Older females had the highest rate of consuming five servings per day, while young males had the lowest rate. These findings, in conjunction with national data, show the need for increasing emphasis on the "5 A Day" campaign.

Adolescent↗
PubMed1990

Exploratory cluster analysis of behavioral risks for chronic disease and injury: implications for tailoring health promotion services.

Identifying population subgroups with similar behavioral risks could assist in the social marketing of health promotion programs by providing target segments to whom services and outreach could be specifically matched. In this paper we describe an exploratory application of cluster analysis to health behavior data from a representative telephone sample of Michigan adults (n = 2,285). In addition to replication of the cluster solution through cross validation, we found significant between cluster demographic differences further confirming cluster validity. Demographic and risk profiles of four clusters are presented, and key health promotion services appropriate to each cluster are discussed. Although further research on the construct validity of the clusters is critical, we conclude that this approach can be useful in tailoring health promotion messages, materials, and services.

Adolescent↗
PubMed1990

A randomized evaluation of smoking cessation interventions for pregnant women at a WIC clinic.

Pregnant smokers attending a local health department WIC clinic were randomly assigned to one of two self-help smoking cessation programs or usual care. The multiple component program resulted in larger quit rates than usual care during the last month of pregnancy (11 percent vs 3 percent) and postpartum (7 percent vs 0 percent). Achieving quit rates in WIC similar to those in studies conducted at prenatal care settings, suggests that smoking cessation programs for low-income pregnant WIC clients are feasible.

Adult↗
PubMed1989

Pregnant women eligible under Medicaid expansion of maternity services. Implications for outreach.

Recent reforms in federal legislation have made Medicaid-financed prenatal care available to pregnant women from households at nearly twice the poverty level. Census and birth certificate data provide little information about the newly eligible group beyond estimates of their size. This article reports on efforts to compare the Medicaid expansion group to traditional Medicaid prenatal care patients in terms of demographics, access problems, and prenatal care adequacy by employing a short-term, hospital-based survey of postpartum women in Michigan. Differences between pregnant women eligible under the expansions and traditionally eligible pregnant women suggested that major changes in outreach and enrollment activities of state Medicaid agencies may be necessary to fulfill the opportunity represented by the Medicaid expansions.

Aid to Families with Dependent Children↗