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W Hodgson

Publications and source records attributed to W Hodgson.

8 recordsLinked to original sources
PubMed2001

Factors associated with student participation in a school-based hepatitis B immunization program.

This study examined the relationship between participation in a school-based hepatitis B immunization program and teacher attitudes toward school-based health care and student socioeconomic factors. A survey addressing teachers' attitudes was administered to all teachers participating in the program. Information regarding student participation in school lunch programs and scores on national standardized tests were collected. Of the 4,874 fifth-grade students targeted for the program, 3,483 (72%) consented to be vaccinated and 3,232 (93% of 3,483) received all three doses of vaccine. Socioeconomic factors were the most important predictors of student participation in this school-based immunization program. Participation was significantly lower among students in schools with a high proportion of students receiving free or reduced-price school lunch and with low test scores. The only teacher factor associated with student participation was whether the teacher had returned the questionnaire. Strategies to increase immunization coverage in school-based programs should target children of low socioeconomic status.

Adult↗
PubMed1999

Differential association of beta2-microglobulin mutants with MHC class I heavy chains and structural analysis demonstrate allele-specific interactions.

Dynamic interactions between major histocompatibility complex (MHC) class I heavy chains and beta2-microglobulin (beta2m) play a critical role in their stability on the cell surface, and their ability to present peptide antigens to CD8+ T-cells. A cursory review of protein sequence homologies and three-dimensional crystal structures of MHC complexes might indicate very similar modes of interaction between the heavy and light chains. In this report, a panel of human beta2m mutants was screened to probe the interactions of beta2m with the murine MHC molecules H-2Kb, -Db, -Kd, -Ld, and -Dd. Binding experiments coupled with analyses of existing three-dimensional crystal structures demonstrate allelic differences in their interaction with beta2m. A comprehensive analysis of the existing murine MHC structures indicates a conformational flexibility on the part of murine beta2m that is not present in beta2m of the human structures. This flexibility is in a region directly interacting with the heavy chain and may relate to its lower affinity for murine heavy chains relative to human beta2m. This defined panel of beta2m mutants of differing affinity may also be useful for subsequent studies of thymic selection, T-cell recognition, and more refined algorithms for protein structure prediction.

Animals↗
PubMed1998

The effect of human beta2-microglobulin on major histocompatibility complex I peptide loading and the engineering of a high affinity variant. Implications for peptide-based vaccines.

The ability to directly load cell surface major histocompatibility complex (MHC) class I molecules with peptides provides a potentially powerful approach toward the development of vaccines to generate cell-mediated immunity. We demonstrate that exogenous beta2-microglobulin (beta2m) stabilizes human cell surface MHC I molecules and facilitates their loading with exogenous peptides. Additionally, using three-dimensional crystal structures and known interaction sites between MHC I heavy chains and beta2m, we engineered variants of human beta2m (hbeta2m) with a single serine substitution at residue 55. This alteration was predicted to promote hydrophobic interactions at the MHC I heavy chain/beta2m interface and displace an ordered water molecule. Compared with hbeta2m, the serine to valine substitution at residue 55 had improved ability to bind to cell surface HLA-A1, HLA-A2, and HLA-A3 molecules, facilitate exogenous peptide loading, and promote recognition by peptide-specific T cells. The inclusion of hbeta2m or higher affinity variants when pulsing cells with MHC-restricted peptides increases the efficiency of peptide loading 50-80-fold. Therefore, the inclusion of hbeta2m in peptide-based vaccines may increase cell surface antigen densities above thresholds that allow recognition of peptide antigens by the immune system, particularly for cryptic, subdominant, or marginally antigenic peptides.

Antigen Presentation↗
PubMed1998

Characterization of the interactions between MHC class I subunits: a systematic approach for the engineering of higher affinity variants of beta 2-microglobulin.

Human beta 2m (h beta 2m) binds to murine MHC I molecules with higher affinity than does murine beta2m and therefore can be used as a model system to define and dissect the interactions between beta2m and MHC I heavy chains that promote the stability of the complex. In the present study we compare three-dimensional crystal structures of human and murine MHC I molecules and use functional studies of chimeric human:murine beta 2m variants to define a region of beta2m that is involved in the higher affinity of h beta 2m for murine MHC I heavy chains. Further examination of the three-dimensional structure in this region revealed conformational differences between human and murine beta2m that affect the ability of an aspartic acid residue at position 53 (D53) conserved in both beta 2ms to form an ionic bond with arginine residues at positions 35 and 48 of the heavy chain. Mutation of residue D53 to either asparagine (D53N) or valine (D53V) largely abrogated the stabilizing effects of h beta 2m on murine MHC I expression in a predictable manner. Based on this observation a variant of h beta 2m was engineered to create an ionic bond between the heavy chain and beta 2m. This variant stabilizes cell surface H-2Dd heavy chains to a greater extent than wild-type h beta 2m. Studying these interactions in light of the growing database of MHC I crystal structures should allow the rational design of higher affinity h beta 2m variants for use in novel peptide-based vaccines capable of inducing cell-mediated immune responses to viruses and tumors.

Animals↗
PubMed1981

Guar gum is not a panacea in diabetes management.

Guar gum was incorporated into the diets of six insulin dependent diabetics drawn from one general practice. Amounts between 6 and 59.6 g daily were used for four to six weeks and compared with a previous two week control period. Unlike some other studies, little improvement was obtained in diabetic control and a small reduction in cholesterol levels occurred. The guar was well tolerated in amounts below 30 g a day.

Adult↗
PubMed1981

Effect of inspiratory flow rate on the esophageal pressure gradient in upright humans.

We measured pressures in 2 lung regions in 5 seated subjects with 2 esophageal balloons placed 7.2 +/- 0.6 cm (mean +/- SE) apart in the mid-thorax in order to obtain the esophageal pressure gradient (EPG). Pressure differences between the lower thoracic balloon and a balloon placed in the stomach were obtained to measure transdiaphragmatic pressure (pdi). Inspiratory maneuvers were made from functional residual capacity (FRC) at either low inspiratory flow rates (slow VI) (mean slow VI: 0.22 +/- 0.05 L/sec) or at rapid flow rates (fast VI) (2.15 +/- 0.15 L/s). At FRC the mean EPG was 0.19 +/- 0.04 cm H2O/cm. The mean EPG was consistently lower at 500 cc above FRC during fast VI (0.14 +/- 0.03 cm H2O/cm) than during slow VI (0.28 +/- 0.05 cm H2O/cm) (P less than 0.001, paired 't' test). Fast VI results in amplification of pressure in the lower as compared to the upper region wih reduction in EPG. Diaphragmatic contraction appears to influence alterations in EPG during fast VI.

Adult↗
PubMedDate not supplied

Ward management: doing the off-duty by computer spreadsheet.

This article describes how the use of a computer spreadsheet system produced tangible benefits in terms of setting, maintaining and analysing a ward's off-duty patterns. The system, which proved easy to operate after initial instruction, is now being reviewed by other departments in the hospital.

Computers↗