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Biomedical subjects

A Biggeri

Publications and source records attributed to A Biggeri.

84 records · Page 5Linked to original sources
PubMedDate not supplied

[Leukemia mortality and incidence of infantile leukemia near the Vatican Radio Station of Rome].

Some recent epidemiological studies suggest an association between lymphatic and haematopoietic cancers and residential exposure to high frequency electromagnetic fields (100 kHz-300 GHz) generated by radio and television transmitters. Vatican Radio, a very powerful radio station transmitting all over the world (up to 600 kW) is located in Santa Maria di Galeria, in the northern suburbs of the city of Rome. Electric field measurements in the proximity of the radio station ranged between 1.5 and 25 V/m. In the 10 km area around the station, with 60.182 residents (1999), leukaemia mortality among adults (> 14 years, 40 cases) in the period 1987-98 and childhood leukaemia incidence in the period 1987-99 (8 cases) were evaluated. The analysis (Stone's conditional test) was performed computing observed and expected cases (reference: population of Rome) in 5 bands of increasing radius (2 km width). The risk of childhood leukaemia was higher than expected within 6 km from the station (Standardized Incidence Ratio = 217; 95% Confidence Interval 99-405). Stone's test showed a significant decrease in risk with increasing distance both for male adult mortality (p-value = 0.03) and for childhood incidence (p-value = 0.04). A Score test, showed a significant decrease in risk of childhood incidence as function of the distance. The main limitations of this study are the small number of observed cases and the use of distance as a proxy for RF exposure. Further research will require a systematic campaign of electromagnetic field measurements to allow better assessment of the population exposure.

Adolescent↗
PubMedDate not supplied

[Prognostic value of various classifications of acute delusional episodes].

A population of 56 cases of acute delusional disorders classified Bouffées délirantes by Pichot's diagnostic criteria is studied. Diagnostic methodology is described. Prognostic factors are assessed from individual variables, using a logistic linear regression model giving the probability of a favourable outcome. These prognostic factors are then adjusted considering gender.

Acute Disease↗
PubMedDate not supplied

[Exertion-induced low back pain: a case-control study of health service workers in a local health unit].

Data concerning all accidents with absence from work exceeding three days were analysed in a cohort of 5000 workers (all employees of a Local Health Unit). A total of 1062 accidents were recorded in the file from 1987 to 1989, 118 coded as "low-back injury". A case-control study design was used to detect the main causes of these accidents, using accidents coded as other than low-back injury as controls. The odds ratios and related confidence limits were calculated in order to assess the degree of association, taking account of potentially confounding factors. A significant relationship was observed between hospital wards and other health service departments rated as "high exposure" and low-back injury (OR high exposure versus low exposure = 2.13; 95% C.L. 1.06-4.29). Selection bias and its influence on the results is also discussed.

Adolescent↗
PubMedDate not supplied

[Analysis of correlated data: problems and examples in industrial medicine].

In occupational health we are frequently faced with data that are not independent, but to recognize the lack of such an independence is not yet a common practice. To help researchers in the field to treat correlated data in a proper way this paper has two aims: to highlight practical situations in which the data are not independent and to show the main differences between a statistical analysis which does consider the correlation appropriately and one which doesn't. As to the first aim, four typical examples are discussed: repeated measurements in the same subject (e.g., cells in which the number of sister chromatid exchanges is counted); health effects observed in multiple organs (e.g., visual impairment in both eyes); evaluation of prevention programs (e.g., exposure assessment to styrene before and after environment remediation); longitudinal studies of health effects (e.g., changes over time of pulmonary function parameters). With respect to the second aim a practical exercise is described completely. Measurements of exposure to a toxic substance in two different departments before and after environment remediation are evaluated with statistical tools which both do and do not consider the correlation between such measurements. Differences in the results obtained, with particular reference to indices of variability (e.g., standard errors), point toward the need of analysing correlated data with appropriate statistical tools that take correlation into account.

Analysis of Variance↗
PubMedDate not supplied

Intralaboratory reproducibility in cervical cytology. Results of the application of a 100-slide set.

In order to evaluate the agreement and accuracy of cervical (vaginal) cytologic diagnoses, 16 cytologists from a large laboratory in Florence, Italy, with experience ranging from 2 to 25 years, independently examined a set of 100 slides. A common reporting form based on a seven-category classification system was used. Concordance was calculated for each pairwise comparison between the 16 cytologists and between each cytologist and the target diagnosis. The values of the kappa statistic for the whole laboratory were .49 for the multiple raters comparison and .59 for the target diagnosis comparison, showing a relatively good degree of agreement.

Cervix Uteri↗
PubMedDate not supplied

A randomized trial on breast self-examination in Faenza (northern-Italy).

AIMS AND BACKGROUND: The aim of this randomized controlled trial was to compare two methods for teaching breast self-examination: theoretical and practical session versus mailed material. METHODS: A random sample of women aged 20-64 years was drawn from the demographic file of the city of Faenza (Northern-Italy). Of 825 sampled eligible women, 168 declined participation, 657 were randomly assigned, after completing a pretest questionnaire aimed at evaluating practice and quality of breast self-examination. Individualised instruction was administered to the treatment group invited to be taught breast self-examination in a medical practice setting. The control group received mailed information about breast self-examination. One year later, 443 women completed the posttest questionnaire. RESULTS: As far as concerns the first outcome of the trial (change in practice of breast-self examination) our study showed, after adjusting for lost-to-follow-up, no difference between the treatment and the control group. The analysis performed to evaluate the second outcome (change in quality of breast self-examination practice) showed that women of the treatment group improved the quality of breast self-examination practice more than the control group (Wilcoxon test, z = 2.4, P < 0.01). The same results have been confirmed by multiple regression analyses taking into account all potential confounders. No selection bias affected these results. CONCLUSION: Theoretical and practical sessions resulted in an improved quality of examination technique than did mailed material.

Adult↗
PubMedDate not supplied

[Influence of the environment on perineal tears in physiological delivery].

INTRODUCTION: In the last decades there was a growing interest in new methods of delivery-assistance and in the literature appeared many new studies. This study shows an analysis of all physiological deliveries (581 women) at the Burresi Hospital of Poggibonsi (SI), Italy, in 1993. From 1984, in this hospital an experimental delivery-room (SPN), where new methods of delivery-assistance are tested (151 women in the period of study), has been used in parallel with a conventional delivery-room (SP)(430 women). RESULTS: The most important difference between the two environments is that in SPN the woman is free to choose her positions during all the phases of delivery. We have evaluated the effect of the different environments on the perineal outcome-intact perineum (41% SPN vs 32% SP), first-degree tears (32% SPN vs 21% SP), second-degree tears (23% SPN vs 21% SP) and mediolateral episiotomy (3% SPN vs 26% SP). Age of the woman, weight of the infant and parity appeared to be most important factors for perineal tears. The SPN reduces significantly the number of perineal tears, when allowing for the other factors. CONCLUSION: It was commonly felt that a reduction in the episiotomy-rate increases the number of perineal tears. Our study shows a protective effect for all levels of perineal outcomes associated with the natural delivery-room. However, for primiparous women a higher risk for first-degree tears is documented in the SPN and should be further evaluated. A selection bias cannot be excluded, due to the observational nature of the present investigation.

Delivery, Obstetric↗
PubMedDate not supplied

[Analysis of correlated data in occupational medicine: examples with binary data].

In a previous paper in this Journal we presented and discussed examples of analysis of correlated data when the response variable was continuous and normally distributed (the measurement of exposure to a toxic substance was the case in point). In this paper we extend the analysis and the discussion to take into account categorical (binary) variables (described in terms of proportions or odds); to favour the comprehension of the analogies (and discrepancies) between the two contexts we have fully developed an example that mimics the situation presented in the previous paper. Marginal, conditional, random effects and transitional models for correlated data are introduced in practical terms; the meaning of the different estimates obtained are interpreted for epidemiological purposes; the disadvantages of not considering correlation in the analysis are explained and the complexities connected to this type of analysis are fully appreciated. It is concluded that correlated data are very frequently encountered in occupational settings and that an appropriate analysis is necessary. This analysis requires sophisticated computer programs and statistical expertise, particularly in the case of categorical data.

Cluster Analysis↗
PubMedDate not supplied

3H-thymidine labelling index (TLI) as a marker of tumour growth heterogeneity: evaluation in human solid carcinomas.

Many studies deal with the analysis of cell kinetic, cytogenetic, biochemical and molecular cell biology parameters to identify prognostic factors relating to tumour growth but all methods use only a small part of the total tumour mass. This study is devoted to the analysis of the heterogeneity of the growth of human solid tumours assaying proliferative activity by means of 3H-thymidine labelling index (TLI) in a fixed number of samples collected in different areas of the lesion (larynx and colon cancers), or in different lesions of the same subject (breast and bladder cancers). Each sample (at the macroscopic level) was divided into small fragments (at the microscopic level) and proliferative activity was determined. The analysis of variance for hierarchical designs demonstrated that in all cases a high component of the variance is attributable to the subjects and to the fragments whereas the variance attributable to the different areas is very low. The heterogeneity of proliferative activity displays a higher focal variability among the fragments (microscopic level) compared with that among areas (macroscopic level) within subjects, provided an adequate number of fragments and cells are counted. In multiple synchronous carcinoma of the bladder the wide variability of proliferation among the single lesions demonstrated that it is necessary to analyse all the tumours in a subject because each one is characterized by a different cell growth potential.

Adult↗