Concurrent validity of a weight-bearing activity questionnaire in prepubertal and pubertal girls and boys

OBJECTIVE

The purpose of this study was to evaluate the current validity of an interviewer-administered physical activity questionnaire against measurement of physical activity from vertical body accelerometer movements in prepubertal and pubertal children.

METHODS

The Weight Bearing Activity Questionnaire for Kids (WBAQK) is an interviewer-administered questionnaire with a recall over 7 days and developed to assess weight-bearing activity in pre-pubertal and pubertal children. The Caltrac(TM) accelerometer was worn for 4-5 days (including 1 weekend day). Thirty-seven schoolgirls and 35 schoolboys participated, with a mean age of 11.2 0.3 years and 12.1 0.2 years, respectively.

RESULTS

Weight-Bearing Score (WBS) and Metabolic Score (MS) derived from the WBAQK were significantly and positively related to the score of the Caltrac(TM). Weight-Bearing Score showed higher correlations in both boys (0.59) and girls (0.53) and slightly better compared to MS (0.54 and 0.35). The classification of boys and girls into high and low activity groups resulted also in a better agreement of WBS (71-72%) than of MS (60-67%) with Caltrac(TM).

CONCLUSIONS

We conclude that the amount of weight-bearing activity can be estimated with the interviewer-administered WBAQK in boys and girls between 8 and 14 years of age.

Identification of potential HLA-A *0201 restricted CTL epitopes derived from the epithelial cell adhesion molecule (Ep-CAM) and the carcinoembryonic antigen (CEA)

The altered expression pattern of the Epithelial Cell Adhesion Molecule (Ep-CAM) and the Carcinoembryonic Antigen (CEA) on tumor cells of epithelial origin as compared to normal epithelia may permit T cells to preferentially recognize and lyse these tumor cells. The binding affinity for human leucocyte antigen A2.1 (HLA-A*0201) and the capacity to form stable peptide-major histocompatibility complex (MHC) interactions with this molecule were tested for 410 Ep-CAM-derived sequences, including an overlapping set of 9 amino-acid-long peptides, and 73 CEA-derived peptides fulfilling the HLA-A*0201 motif. Peptides with a high binding affinity and a low peptide-MHC dissociation rate were subsequently tested for their immunogenicity in HLA-A*0201Kb transgenic mice. One Ep-CAM-derived peptide and 1 CEA-derived peptide were able to reproducibly induce peptide-specific cytotoxic T cells (CTL) in these mice. This indicates that EpCAM and CEA are potential target antigens for CTL-mediated immunotherapy of epithelial cancers.

An HLA class I peptide-binding assay based on competition for binding to class I molecules on intact human B cells. Identification of conserved HIV-1 polymerase peptides binding to HLA-A*0301

A peptide-binding assay employing the HLA class I molecules on intact human B cells is described. The peptide antigens are stripped from the HLA class I molecules by mild acid treatment, after which the cells are incubated with a FL-labeled reference peptide together with different concentrations of the peptide of interest. The effectiveness by which the latter peptide competes for binding to the HLA class I molecules is assayed by measuring the amount of HLA-bound FL-labeled reference peptide with FACscan analysis. The assay is easy to perform because there is no need to purify HLA class I molecules, or to transfect cells with HLA class I molecules, and no radioactive label is used. Moreover, large panels of HLA-typed human B-cell lines are available as tools for peptide binding to a vast array of HLA molecules. The binding assay was optimized and validated with peptides of known binding capacity to either HLA-A*0201 or HLA-A*0301. The kinetics of peptide binding in this assay were shown to be comparable to that in assays employing soluble HLA class I molecules. Application of the assay in the search for potential HLA-A*0301 restricted CTL epitopes, derived from HIV-1 polymerase, resulted in the identification of five high-affinity binding peptides.

Cytotoxic T lymphocytes raised against a subdominant epitope offered as a synthetic peptide eradicate human papillomavirus type 16-induced tumors

Previously, we have shown that immunization with human papillomavirus (HPV) type 16-derived cytotoxic T lymphocyte (CTL) epitope E7 49-57 (RAHYNIVTF) renders C57BL/6 mice insensitive to tumors formed by HPV16-transformed cells. In this study, we provide evidence that E7 49-57 is expressed as a subdominant CTL epitope on HPV16-transformed C57BL/6 cells. Using acid peptide elution, it is shown that HPV16-transformed cells express another CTL epitope, besides E7 49-57, which appears to be dominant. We demonstrate that a CTL line raised against the subdominant CTL epitope, offered as synthetic peptide E7 49-57, eradicates established HPV16-induced tumors in mice. Our data show that synthetic peptide-induced CTL can be applied successfully in vivo against (virus-induced) tumor, and emphasize that subdominant CTL epitopes are useful targets for immunotherapy. Furthermore, it is illustrated for the first time that HPV16-specific CTL interfere directly with HPV16-induced tumors.

Excessive hepatitis-B surface antigen production after corticosteroids and the development of immunoblastic lymphoma

The development of B-cell immunoblastic lymphoma in a 51 year old patient with hepatitis B virus related immune complex nephritis is described. The lymphoma was diagnosed eleven months after the administration of high dose corticosteroids which resulted in a striking increase in the HBsAg serum titer up to 1:1,000,000. This unusual association raises a number of interesting questions regarding the link between immune complex nephritis and immunoblastic lymphoma. The significance of corticosteroid therapy leading to excessive HBsAg secretion and the role played by this intense antigenic stimulation in the pathogenesis of lymphoma in this particular patient are also discussed.

Mspl RFLP at the D5S122 locus tightly linked to APC

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