Use of clinical risk factors to identify postmenopausal women with vertebral fractures

INTRODUCTION AND HYPOTHESIS

Previous studies have been unable to identify risk factors for prevalent vertebral fractures (VF), which are suitable for use in selection strategies intended to target high-risk sub-groups for diagnostic assessment. However, these studies generally consisted of large epidemiology surveys based on questionnaires and were only able to evaluate a limited number of risk factors. Here, we investigated whether a stronger relationship exists with prevalent VF when conventional risk factors are combined with additional information obtained from detailed one-to-one assessment.

METHODS

Women aged 65-75 registered at four geographically distinct GP practices were invited to participate (n=1,518), of whom 540 attended for assessment as follows: a questionnaire asking about risk factors for osteoporosis such as height loss compared to age 25 and history of non-vertebral fracture (NVF), the get-up-and-go test, Margolis back pain score, measurement of wall-tragus and rib-pelvis distances, and BMD as measured by the distal forearm BMD. A lateral thoraco-lumbar spine X-ray was obtained, which was subsequently scored for the presence of significant vertebral deformities.

RESULTS

Of the 509 subjects who underwent spinal radiographs, 37 (7.3%) were found to have one or more VF. Following logistic regression analysis, the four most predictive clinical risk factors for prevalent VF were: height loss (P=0.006), past NVF (P=0.004), history of back pain (P=0.075) and age (P=0.05). BMD was also significantly associated with prevalent VF (P=0.002), but its inclusion did not affect associations with other variables. Factors elicited from detailed one-to-one assessment were not related to the risk of one or more prevalent VFs. The area under ROC curves derived from these regressions, which suggested that models for prevalent VF had modest predictive accuracy, were as follows: 0.68 (BMD), 0.74 (four clinical risk factors above) and 0.78 (clinical risk factors + BMD). Analyses were repeated in relation to the subgroup of 13 patients with two or more VFs, which revealed that in this instance, the Margolis back pain score and rib-pelvis distance were associated with the presence of multiple VFs (P=0.022 and 0.026, respectively). Moreover, the predictive value as reflected by the ROC curve area was improved: 0.80 (BMD), 0.88 (the four most predictive clinical risk factors consisting of the height loss, past NVF, Margolis back pain score and rib-pelvis distance) and 0.91 (clinical risk factors + BMD).

CONCLUSIONS

Evaluation of additional risk factors from detailed one-to-one assessment does not improve the predictive value of risk factors for one or more prevalent vertebral deformities in postmenopausal women. However, the use of factors such as the Margolis back pain score and rib-pelvis distance may be helpful in identifying postmenopausal women at high risk of multiple prevalent VFs.

Adverse reactions to synthetic food colours: interactions between tartrazine and muscarinic acetylcholine receptors in isolated guinea-pig ileum

The ability of selected food colours to interact with isolated guinea-pig ileum was investigated using a gut bath system. Studies revealed that guinea-pig ileum was specifically sensitive to tartrazine. Intestinal contraction occurred dose-dependently down to a minimum effective dose of 10 microM. All other colours examined proved negative. Studies investigating the biological activity of structural analogues of tartrazine revealed the ability to initiate intestinal contraction was associated with the presence of the carboxylic acid residue at the R1 position of the pyrazole ring. Blocking studies showed that tartrazine contraction was inhibited by atropine alone but not by any other blocking agent tested, implying that tartrazine acts either directly or indirectly upon the muscarinic acetylcholine receptor associated with parasympathetic innervation.

Extravasation assay for the assessment of intestinal reactions to orally presented compounds

Adverse reactions characteristic of food intolerance are claimed to occur in susceptible individuals following exposure to various chemical additives used to colour, flavour or preserve food. The objective of the present study was to develop a method suitable for investigating the nature and mechanism of these reactions in an animal model. Our results demonstrate that intestinal responses, elicited either specifically following oral challenge by antigen or non-specifically by the direct action of a chemical, can be quantified by evaluating the intestinal extravasation (IEV) of intravenously administered 125I-labelled rat albumin.

Suppression of thymocyte proliferation in vitro by a dioctyltin dichloride-induced serum factor

Oral administration of dioctyltin dichloride (DOTC) results in the production or release of factors which appear to prevent thymocyte maturation at an early stage. Sera obtained from rats gavaged with 75 mg DOTC/kg on alternate days, significantly inhibited PHA-induced blastogenesis of normal thymocytes. In vitro uptake of tritiated thymidine by thymocytes obtained from DOTC-gavaged rats was markedly reduced. These events occurred 24 to 72 h after commencement of DOTC treatment and preceded overt thymic weight loss. The effects of DOTC may therefore be a consequence of factor(s) capable of blocking the intrathymic differentiation of T cell precursors.

Proposed standards for professional health sciences library services in hospitals of New York State

Hospital libraries are considered to be the basic unit of the medical information system. A major statewide effort was begun in 1978 to introduce and support legislation in the New York State Legislature which would encourage hospitals to establish and maintain libraries that meet minimum services standards. Included in this legislation is the concept that the Commissioner of Education in consultation with the Commissioner of Health shall have the power to establish standards for hospital libraries. The Ad Hoc Committee for the Promotion of Hospital Library Services, Western New York Library Resources Council, proposes The Standards for Professional Health Sciences Library Services in Hospitals of New York State to clarify and to strengthen existing hospital library standards. These standards differ specifically from the Joint Commission on Accreditation of Hospitals standards in that they place equal and specific emphasis on eleven points: administration, qualifications of library staff, continuing education of library staff, requirement for a library advisory committee, required library services, required library resources, library space requirements, library budget, library network and consortium membership, documentation of library policy, and continued evaluation of the needs of the hospital for library service. Detailed interpretations are provided. An appendix describes the qualifications of a hospital library consultant.