A longitudinal study investigating change in BMI z-score in primary school-aged children and the association of child BMI z-score with parent BMI

Background

This paper aims to explore change in BMI z-score through childhood and the association between parent BMI and child BMI z-score. This is important to understand for the development of effective obesity interventions.

Methods

Data from the longitudinal B-ProAct1v study (1837 participants) were analysed. A paired sample t-test examined changes in child BMI z-score between Year 1 and 4. Multivariable linear regression models examined the cross-sectional associations between child BMI z-score and parent BMI in Year 1 and 4. The influence of change in parental BMI between Year 1 and Year 4 on child BMI z-score in Year 4 was explored through regression analyses, adjusted for baseline BMI z-score.

Results

There was a strong association between child BMI z-score at Year 1 and 4. Child mean BMI z-score score increased from 0.198 to 0.330 (p = < 0.005) between these timepoints. For every unit increase in parent BMI, there was an increase in child BMI z-score of 0.047 in Year 1 (p = < 0.005) and of 0.059 in Year 4 (p = < 0.005). Parental BMI change was not significantly associated with Year 4 child BMI z-score.

Conclusion

The key indicator of higher child BMI at Year 4 is high BMI at Year 1. Further studies are needed to explore the impact of parental weight change on child BMI z-score and whether interventions targeted at overweight or obese parents, can improve their child’s BMI z-score.

Intraepithelial gammadelta+ lymphocytes maintain the integrity of intestinal epithelial tight junctions in response to infection

BACKGROUND & AIMS

Intestinal epithelial integrity and permeability is dependent on intercellular tight junction (TJ) complexes. How TJ integrity is regulated remains unclear, although phosphorylation and dephosphorylation of the integral membrane protein occludin is an important determinant of TJ formation and epithelial permeability. We have investigated the role intestinal intraepithelial lymphocytes (iIELs) play in regulating epithelial permeability in response to infection.

METHODS

Recombinant strains of Toxoplasma gondii were used to assess intestinal epithelial barrier function and TJ integrity in mice with intact or depleted populations of iIELs. Alterations in epithelial permeability were correlated with TJ structure and the state of phosphorylation of occludin. iIEL in vivo reconstitution experiments were used to identify the iIELs required to maintain epithelial permeability and TJ integrity.

RESULTS

In the absence of gammadelta+ iIELs, intestinal epithelial barrier function and the ability to restrict epithelial transmigration of Toxoplasma and the unrelated intracellular bacterial pathogen Salmonella typhimurium was severely compromised. Leaky epithelium in gammadelta+ iIEL-deficient mice was associated with the absence of phosphorylation of serine residues of occludin and lack of claudin 3 and zona occludens-1 proteins in TJ complexes. These deficiencies were attributable to the absence of a single subset of gammadelta T-cell receptor (TCR-Vgamma7+) iIELs that, after reconstituting gammadelta iIEL-deficient mice, restored epithelial barrier function and TJ complexes, resulting in increased resistance to infection.

CONCLUSIONS

These findings identify a novel role for gammadelta+ iIELs in maintaining TJ integrity and epithelial barrier function that have implications for understanding the pathogenesis of intestinal inflammatory diseases associated with disruption of TJ complexes.

Identification of novel gammadelta T-cell subsets following bacterial infection in the absence of Vgamma1+ T cells: homeostatic control of gammadelta T-cell responses to pathogen infection by Vgamma1+ T cells

Although gammadelta T cells are a common feature of many pathogen-induced immune responses, the factors that influence, promote, or regulate the response of individual gammadelta T-cell subsets to infection is unknown. Here we show that in the absence of Vgamma1+ T cells, novel subsets of gammadelta T cells, expressing T-cell receptor (TCR)-Vgamma chains that normally define TCRgammadelta+ dendritic epidermal T cells (DETCs) (Vgamma5+), intestinal intraepithelial lymphocytes (iIELs) (Vgamma7+), and lymphocytes associated with the vaginal epithelia (Vgamma6+), are recruited to the spleen in response to bacterial infection in TCR-Vgamma1-/- mice. By comparison of phenotype and structure of TCR-Vgamma chains and/or -Vdelta chains expressed by these novel subsets with those of their epithelium-associated counterparts, the Vgamma6+ T cells elicited in infected Vgamma1-/- mice were shown to be identical to those found in the reproductive tract, from where they are presumably recruited in the absence of Vgamma1+ T cells. By contrast, Vgamma5+ and Vgamma7+ T cells found in infected Vgamma1-/- mice were distinct from Vgamma5+ DETCs and Vgamma7+ iIELs. Functional analyses of the novel gammadelta T-cell subsets identified for infected Vgamma1-/- mice showed that whereas the Vgamma5+ and Vgamma7+ subsets may compensate for the absence of Vgamma1+ T cells by producing similar cytokines, they do not possess cytocidal activity and they cannot replace the macrophage homeostasis function of Vgamma1+ T cells. Collectively, these findings identify novel subsets of gammadelta T cells, the recruitment and activity of which is under the control of Vgamma1+ T cells.

Proteomic analysis of melanoma-derived exosomes by two-dimensional polyacrylamide gel electrophoresis and mass spectrometry

Exosomes are 40-100 nm vesicles released by numerous cell types and are thought to have a variety of roles depending on their origin. Exosomes derived from antigen presenting cells have been shown to be capable of initiating immune responses in vivo and eradicating established tumours in murine models. Tumour-derived exosomes can be utilised as a source of tumour antigen for cross-priming to T-cells and are thus of interest for use in anti-tumour immunotherapy. Further exploration into the protein composition of exosomes may increase our understanding of their potential roles in vivo and this study has examined the proteome of exosomes purified from cell supernatants of the melanoma cell lines MeWo and SK-MEL-28. The vesicular nature and size (30-100 nm) of the purified exosomes was confirmed by electron microscopy and sucrose density gradient centrifugation. Western blotting demonstrated the absence of calnexin and cytochrome c, verifying the purity of the exosome preparations, as well as enrichment of MHC class I and the tumour-associated antigens Mart-1 and Mel-CAM. The two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) protein profiles of exosomes from the two cell lines were highly comparable and strikingly different from the profiles of the total cell lysates. Mass spectrometric sequencing identified proteins present in 49 protein spots in the exosome lysates. Several of these have been identified previously in exosomes but some are novel, including p120 catenin, radixin, and immunoglobulin superfamily member 8 (PGRL). Proteins present in whole-cell lysates that were significantly reduced or excluded from exosomes were also identified and included several mitochondrial and lysosomal proteins, again confirming the proposed endosomal origin of exosomes. This study presents a starting point for future more in-depth protein studies of tumour-derived exosomes which will aid the understanding of their biogenesis and targeting for use in anti-tumour immunotherapy protocols.

Development and validation of a questionnaire to evaluate the effectiveness of evidence-based practice teaching

AIM

The aim of this study was to develop and validate a questionnaire to evaluate the effectiveness of evidence-based practice (EBP) teaching.

METHODS

The 152 questionnaires completed by health care professionals with a range of EBP experience were used in this study. Cronbach's alpha for the knowledge and attitude questions indicated a satisfactory level of internal consistency (i.e. >0.60).

RESULTS

The discriminative validity was evidenced by a statistically significant difference in the knowledge and attitude scores of 'novices' (i.e. little or no prior EBP education) compared with 'experts' (i.e. health care professionals and academics currently teaching EBP). Moderate to good (> or =0.4) sensitivity index scores were observed for both knowledge and attitude scores as the result of comparing individuals before and after an EBP intervention.

CONCLUSIONS

The results of this validation study indicate that the developed questionnaire is a satisfactory tool with which to evaluate the effectiveness of EBP teaching interventions.

A preliminary study of the decision-making process within general practice

OBJECTIVE

The aim of the present study was to explore the factors that contribute to the process of decision making within general practice, over and above evidence-based information.

METHODS

A qualitative study was conducted using semi-structured interviews on a purposeful sample of GPs, based in the South West of England. Each interview was tape-recorded and transcribed verbatim.

RESULTS

Five broad categories emerged from the data: practitioner; patient; practitioner-patient relationship; verbal and non-verbal communication; evidence-based medicine; and external factors.

CONCLUSION

The nature of general practice is such that the process of making clinical decisions is complex. In an era when GPs are being overwhelmed by evidence-based information, consideration needs to be given to the implications that the nature of the decision-making process has upon the way 'evidence' is constructed and promoted within general practice.

A systematic review of the effectiveness of critical appraisal skills training for clinicians

The aim of this paper is to undertake a descriptive systematic review of the effectiveness of critical appraisal skills training for clinicians. Of the 10 controlled studies which examined this issue and were found to meet the eligibility criteria of this review, all used a study population of either medical students or doctors in training. The studies used a variety of different intervention 'dosages' and reported a range of outcomes. These included participants' knowledge of epidemiology/biostatistics, their attitudes towards medical literature, their ability to appraise medical literature, and medical literature reading behaviour. An overall improvement in assessed outcomes of 68% was reported after critical appraisal skills training, particularly in knowledge relating to epidemiology and biostatistics. This review appears to provide some evidence of the benefit of teaching critical appraisal skills to clinicians, in terms of both knowledge of methodological/statistical issues in clinical research and attitudes to medical literature. However, these findings should be considered with caution as the methodological quality of studies was generally poor, with only one study employing a randomized controlled design. There is a need for educators within the field of evidence-based health to consider the implications of this review.

Demographic characteristics of the population of Greater Soweto, 1993

"This research note provides information and findings on some aspects of urbanisation in Greater Soweto. It outlines the demographic characteristics of the population, namely the characteristics of households; household preferences for services; perceptions on accommodation; age and gender profiles; education levels; the origin of the inhabitants and mobility in and migration to Greater Soweto. Some findings are particularly important for future planning of services and low-income or subsidised housing."