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S Richardson

Publications and source records attributed to S Richardson.

At least 127 records · Page 7Linked to original sources
PubMed1992

Meningococcal disease and influenza-like syndrome: a new approach to an old question.

The temporal and spatial association of meningococcal disease and influenza-like syndrome (ILS) was assessed from surveillance data on these diseases in France for a 6-year period (1985-1990). Using time series methods to account for the usual seasonal pattern meningococcal disease, the incidence of meningococcal disease in a given week was found to be linked to incidence of ILS in the 5 previous weeks but not to that in subsequent weeks. Geographic spread of meningococcal disease correlated with spread of ILS. This study also suggests that meningococcal disease is more severe for a 2-month period during and after an ILS epidemic: The proportion of cases with purpura fulminans increased by 24% and those resulting in death by 26% during this period. No shift in the age distribution was observed. When an ILS epidemic is identified, medical practitioners should be informed of the likelihood of an increased incidence and severity of meningococcal disease.

Adolescent↗
PubMed1992

[Statistic modeling of geographic and epidemiologic variations].

In epidemiology, studies of the geographical variations of mortality or incidence rates for some chronic diseases have often given rise to etiological clues concerning those diseases. In this framework the variables concerned have a spatially autocorrelated structure which has to be taken into account in the statistical analysis. The statistical techniques used to study in the first place the spatial variations of mortality rates and then the joint geographical variations of mortality and exposure indices are reviewed. Emphasis is placed on the importance played by the geographical scale of the analysed data in the modelling process as well as on the interpretation problems of geographical correlation studies.

Bias↗
PubMed1991

Imaging of haemodialysis-associated amyloidosis with 123I-serum amyloid P component.

Long-term haemodialysis is frequently complicated by amyloid deposition in which the fibrils consist of beta 2-microglobulin. Dialysis-related amyloid disease causes extensive morbidity and has been associated with deaths in some cases. All amyloid deposits contain amyloid P component that is derived from the normal circulating protein, serum amyloid P component (SAP). We have used scintigraphic imaging after injection of 123I-labelled SAP to assess the distribution of amyloidosis in 38 patients receiving long-term haemodialysis for end-stage renal failure. There was focal localisation of tracer at all sites where histological examination confirmed amyloid deposition. Splenic uptake was seen in 12 patients, indicating splenic amyloidosis, but there was no evidence of other visceral involvement. 6 control subjects who had been dialysed for under 1.5 years showed no localisation of tracer, nor was there any uptake of 123I-labelled human serum albumin in 3 long-term dialysis patients with histologically confirmed amyloidosis and positive 123I-SAP images. Negative scans were also obtained in 5 patients who had been transplanted 0.8-2.4 years previously, despite past evidence of dialysis arthropathy (5) and histologically proven amyloidosis (4). 123I-SAP scintigraphy may be helpful as a non-invasive method for both the diagnosis and monitoring of dialysis-associated amyloidosis.

Amyloidosis↗
PubMed1991

The role of fat, animal protein and some vitamin consumption in breast cancer: a case control study in southern France.

The role of the consumption of fat, animal protein and vitamins on breast-cancer risk was investigated in a hospital-based case-control study of 924 patients (409 cases and 515 controls) in Montpellier (France). A dietary history questionnaire, administered by interview, comprising 55 key food items as well as beverage consumption, and including food frequencies and portion sizes, was used to measure the intake of total fat and its constituents, animal protein, retinol, beta-carotene, vitamin E and alcohol consumption. The questionnaire also elicited information on relevant medical history and personal characteristics. All food items which showed significantly elevated odds ratio (high-fat cheese, desserts and chocolate and processed pork meat) in a multivariate analysis contained a high proportion of animal fat. This is reflected in the nutrient analysis, which showed a significant linear trend as well as an elevated odds ratio for the highest tertile of consumption of total fat [OR3 = 1.6 (1.1-2.2)], animal fat [OR3 = 1.6 (1.1-2.2)], saturated fat [OR3 = 1.9 (1.3-2.6)] and mono-unsaturated fat [OR3 = 1.7 (1.2-2.5)]. For post-menopausal women, there is a particularly strong association with saturated fat [OR3 = 3.3 (1.4-7.8)] in a multivariate analysis including all other significant nutrients. There is no evidence of an increase of risk with the intake of animal protein and no evidence of risk reduction with increased consumption of vegetables, beta-carotene or vitamin E. Along with some recent studies, our results give support to the hypothesis that dietary fat is a risk factor in breast carcinogenesis.

Adult↗
PubMed1991

Zinc and copper in breast cancer. A joint study in northern Italy and southern France.

The relationship between breast cancer and two trace elements, zinc (Zn) and copper (Cu), was investigated by means of an hospital based case-control study at Milan (Italy) and Montpellier (France). Variables concerning dietary intake of Zn and Cu (in Milan) and their blood levels (both in Milan and Montpellier) were measured. Dietary intake, evaluated through a questionnaire of the dietary history type, and blood levels of Zn and Cu were measured in 261 cases and 261 controls. Cu blood level showed a contradictory tendency in the two samples (higher in controls in Milan, higher in cases in Montpellier), which tended to lessen after adjustment for related variables. No odds ratios (OR) in the different quantiles, nor X2 for trend reached statistical significance. A sharp difference was evidenced on the opposite with regard to Zn blood values in cases and controls. In both samples Zn mean values are significantly higher in cases than in controls, and the difference remains significant in the two samples even after adjustment for related variables. The pooled OR computed from the two samples, after adjustment for known risk factors and related variables, reaches in the fourth quartile a value of 9.5 (CI: 4.9-18.2). Dietary intake of the two minerals (measured only in Milan sample) showed no difference between cases and controls, but a stronger relationship between dietary and blood Zn was evidenced in cases with respect to controls. The authors suggest that the higher Zn level in cases might be related with an higher incorporation of Zn in cancer cases and that the same mineral might play a possible role in tumor growth promotion.

Adult↗
PubMed1991

Empirical Bayes estimates of cancer mortality rates using spatial models.

We give results of empirical Bayes (EB) estimation of mortality rates designed to smooth observed SMR when random fluctuation of the observed deaths is important. We have specially studied the case where the prior distributions of the EB method have a spatial structure. The need for spatial modelling of cancer mortality rates in France is first shown with testing autocorrelation and fitting autoregressive spatial models, conditional (CAR) or simultaneous (SAR). A positive autocorrelation of the rates is shown for most cancer sites studied. As expected, EB estimates of mortality rates for common tumours are similar to SMRs. For rare tumours, the EB method identifies the extreme rates more clearly than SMRs by smoothing the SMRs with large variances. CAR or SAR models are adequate prior distributions for autocorrelated rates and produce quite similar rate estimates.

Bayes Theorem↗
PubMed1991

A time series construction of an alert threshold with application to S. bovismorbificans in France.

Epidemiological surveillance can be used to initiate preventive measures and Salmonella infection is a prime example of application. It is important that any unusual increase of reported cases should be detected as rapidly as possible. Reliable forecasts based on a suitable model of the temporal structure of a pathological indicator are necessary for the elaboration of an alert threshold. We first discuss the specific problems associated with the identification and the estimation of the temporal structure of indicators of infectious diseases when they present both epidemic peaks and an underlying stationary structure. Then we consider how an alert threshold can be defined. Our application concerns infections caused by S. bovismorbificans in France for which an alert threshold is constructed and tested both retrospectively and prospectively.

France↗
PubMed1991

The pattern of risk factors for breast cancer in a southern France population. Interest for a stratified analysis by age at diagnosis.

A hospital-based case-control study was conducted over 4 years in Southern France to assess the pattern of established risk factors for breast cancer and to examine its variation according to age at diagnosis. Cases studied (450) were women admitted to the Montpellier Cancer Institute, with histologically confirmed primary breast carcinoma. Controls (576) were patients from a nearby hospital admitted in the early stages of a neurological or mild psychological diseases and from a clinic for general surgery. Any patient with malignant tumours, chronic and cardiovascular diseases were excluded. The total population globally showed the commonly reported pattern for these risk factors. When stratified by age, the reproductive factors occurring early in life (menarche, first full term pregnancy) were shown to be significant risk factors only in the youngest group of patients and do not seem to influence risk in older women, for whom risk factors are those occurring later in life (menopause, obesity). This suggests a complex involvement of the reproductive and sociodemographic features with the various stages of the 'natural history' of breast cancer.

Adult↗
PubMed1991

The timed "Up & Go": a test of basic functional mobility for frail elderly persons.

This study evaluated a modified, timed version of the "Get-Up and Go" Test (Mathias et al, 1986) in 60 patients referred to a Geriatric Day Hospital (mean age 79.5 years). The patient is observed and timed while he rises from an arm chair, walks 3 meters, turns, walks back, and sits down again. The results indicate that the time score is (1) reliable (inter-rater and intra-rater); (2) correlates well with log-transformed scores on the Berg Balance Scale (r = -0.81), gait speed (r = -0.61) and Barthel Index of ADL (r = -0.78); and (3) appears to predict the patient's ability to go outside alone safely. These data suggest that the timed "Up & Go" test is a reliable and valid test for quantifying functional mobility that may also be useful in following clinical change over time. The test is quick, requires no special equipment or training, and is easily included as part of the routine medical examination.

Activities of Daily Living↗
PubMed1991

Serological responses to the B subunit of Shiga-like toxin 1 and its peptide fragments indicate that the B subunit is a vaccine candidate to counter action of the toxin.

The B subunit of Shiga toxin and Shiga-like toxin (SLT-1) and its fragments are potentially immunogenic and may generate protective humoral responses against the action of these toxins. We have analyzed the antibody response of rabbits immunized with pure B subunit of SLT-1 or synthetic fragments of the subunit. The immune response to the native B subunit was found to be largely directed at conformational epitopes. More importantly, rabbits immunized with the B subunit were protected from a lethal challenge with SLT-1, indicating that the B subunit represents an excellent vaccine candidate to counter the effects of Shiga toxin and SLT-1 in humans. Polyclonal antibodies against a synthetic peptide corresponding to residues 28 to 40 of the B subunit neutralized the cytotoxicity of SLT-1 towards Vero cells. This region is thus exposed in the native state of the B subunit. The sequence specificity of other antipeptide antisera also provides clues to the state of folding and assembly of the B subunit. Antisera to synthetic peptides representing the N- and C-terminal regions of the SLT-1 B subunit did not cross-react with native B subunit but strongly recognized denatured forms of the protein. Finally, the monoclonal antibody 13C4 was shown to bind to a discontinuous epitope expressed only on the native form of the protein. These immunological reagents can be used to probe the conformational state of the B subunit and the holotoxin as it relates to their functional properties.

Amino Acid Sequence↗
PubMed1991

Antioxidants in female breast cancer patients.

Blood levels of selenium, zinc, copper, and vitamins E and C were measured in 48 cases and 50 controls from a hospital-based case-control study bearing on breast cancer risk factors in Montpellier (France). Cellular levels of selenium and vitamins E and C were also evaluated in most of the subjects. We found that the blood and cellular levels of these antioxidants were overall higher in cases than in controls, significantly for serum zinc, plasma, and leukocyte vitamin E. The statistical significance of the difference between case and control serum Cu crude levels disappeared after adjustment for metabolically related variables. The difference was borderline significant for leukocyte vitamin C. These results were slightly modified when vitamin pill users were excluded from case and control samples. The serum zinc odds ratios computed after adjustment for related variables were significantly elevated (2.53, confidence interval: 1.34-4.78, for the highest tertile) as were those computed previously for pooled plasma vitamin E levels in a joint study.

Adult↗
PubMed1990

The role of diet history and biologic assays in the study of "diet and breast cancer".

Nutritional factors related to breast cancer were investigated by means of a hospital-based case-control study in Milan (Italy) and Montpellier (France). Liposoluble vitamins, cholesterol and triglycerides were measured in blood samples taken from interviewed subjects (319 cases and 344 controls). In addition serum zinc and copper was assessed in the Italian samples and serum fatty acids and malonyl-di-aldehyde in the French samples. A significant difference was found between cases and controls in total fat and cholesterol intake in both populations, and in saturated fatty acid and mono-unsaturated fatty acid consumption in the French samples. No difference emerged in liposoluble vitamin consumption in both populations nor in zinc and copper consumption in the Italian samples. A statistically significant higher serum level of cholesterol and plasma level of vitamin E was observed in cases compared to controls in both populations. The difference in plasma vitamin E was confirmed after adjustment on total cholesterol and triglycerides. Similarly, zinc serum level was higher in Italian cases than in Italian controls, while malonyl-di-aldehyde was lower in French cases than French controls. A multivariate analysis was performed after classification of cases and controls according to quantile distribution of controls. Nutrient consumption and relevant blood markers were directly or partially correlated in both populations. All known risk factors plus age, serum total cholesterol and triglycerides were used as covariates. The odds ratio values for the highest quantiles are: Dietary cholesterol, OR = 1.9 (1.1-3.4); total dietary lipids, OR = 1.9 (1.0-3.4); plasma vitamin E, OR = 4.2 (1.9-9.0); serum zinc, OR = 12.2 (5.4-27.7); serum malonyl-di-aldehyde, OR = 0.56 (0.33-0.97).

Breast Neoplasms↗
PubMed1990

A method for testing the significance of geographical correlations with application to industrial lung cancer in France.

This paper discusses some of the problems encountered when testing significance in geographical epidemiology where variables typically exhibit some spatial autocorrelation. A test of partial correlation between spatially autocorrelated variables is presented. It is based on evaluation of an effective sample size which takes account of spatial structure. Performance is assessed by Monte Carlo simulation. The proposed method is used to study male lung cancer rates in specific industries in France.

France↗
PubMed1990

Acute leukaemia in workers exposed to electromagnetic fields.

Results from a French case-control study of acute leukaemia and occupational exposure for the risk associated with exposure to electromagnetic fields (EMF) are reported. There were 185 cases and 513 controls. A significantly increased risk of acute leukaemia was observed for exposure to EMF other than that from arc welding (odds ratio = 4.04, 95% CI 1.26-12.88) which persisted after adjustment for possible confounding exposures. This study supports the hypothesis that workers exposed to some EMF have an increased risk of leukaemia.

Acute Disease↗
PubMed1990

Anxiety and unrealistic optimism.

Substantial evidence suggest that people tend to be unrealistically optimistic that positive events will happen to them and that negative events will not. However, recent research indicates that under certain conditions they may be unrealistically pessimistic. Variations in the levels of optimism and pessimism experienced towards events are generally given cognitive explanations. A relation between optimism and pessimism and anxiety, a variable related to emotion as well as cognition, was investigated in the present study. An inverse correlation was found between how anxious female students in England felt about certain negative events and how unrealistically optimistic they were about the occurrence of those events. It was concluded that the degree of anxiety experienced toward a negative event may affect the level of unrealistic optimism or pessimism toward it.

Adaptation, Psychological↗