Search PubMed⌕ Search

Biomedical subjects

R Ferry

Publications and source records attributed to R Ferry.

At least 19 recordsLinked to original sources
PubMed1998

[Short-term modeling of the effect of air pollution on health. Example: SO2 and total mortality, Paris 1987-1999].

Since 1990, many epidemiological time series studies have provided evidence that ambient air pollution levels have adverse health effects. The ERPURS study (Evaluation des Risques de la Pollution Urbaine pour la Santé) has permitted to quantify this impact in the Paris region. This study was based on an ecological time series approach. We present, step by step, the method used, illustrated by an example: association between SO2 levels and total mortality (excluding external causes), 1987-1990. Mortality modelling has taken trend into account by a linear term, seasons by trigonometrics functions sum, day of the week effects by 6 dummy variables, temperature peak by a dummy variable, influenza epidemics by appropriate variables, mean temperature by linear and quadratic terms, relative humidity by a linear term. SO2 1 day lag was introduced in the model by a linear term. The central issue is the control of seasonal variations and long term trend. An inadequate control can lead to some spurious results. The relationship between mortality and weather variables is generally nonlinear. The use of statistical and graphical diagnostics, are necessary at each step. Time series analysis are important tools to study short term relationship between air pollutants and health indicators. The method applied in the ERPURS study is only one of the possible approaches. Whatever the method used, it is important to understand the underlying process of the data and to control for confounding factors with the appropriate method for the temporal structure of the data.

Air Pollutants↗
PubMed1997

Air pollution and doctors' house calls: results from the ERPURS system for monitoring the effects of air pollution on public health in Greater Paris, France, 1991-1995. Evaluation des Risques de la Pollution Urbaine pour la Santé.

This study examines short-term relationships between doctors' house calls and urban air pollution in Greater Paris for the period 1991-1995. Poisson regressions using nonparametric smoothing functions controlled for time trend, seasonal patterns, pollen counts, influenza epidemics, and weather. The relationship between asthma visits and air pollution was stronger for children. A relative risk (RRP95/P5) of 1.32 [95% confidence interval (CI) = 1.17-1.47)] was observed for an increase from the 5th to the 95th percentile (7-51 micrograms/m3) in daily concentrations of black smoke (BS). The risks for 24-hr sulfur dioxide and nitrogen dioxide levels were in the same range. Cardiovascular conditions, considered globally, showed weaker associations than angina pectoris/myocardial infarction, for which RRP95/P5 was 1.63 (95% CI = 1.10-2.41) in relation to ozone ambient levels. Eye conditions were exclusively related to ozone (RRP95/P5 = 1.17, 95% CI 1.02-1.33). Asthma visits and ozone showed an interaction with minimum temperature: an effect was observed only at 10 degrees C or higher. In two-pollutant models including BS with, successively, SO2, NO2, and O3, only BS and O3 effects remained stable. Along with mortality and hospital admissions, house call activity data, available on a regular basis, may be a sensitive indicator for monitoring health effects related to air pollution.

Air Pollutants↗
PubMed1996

Short term respiratory health effects of ambient air pollution: results of the APHEA project in Paris.

STUDY OBJECTIVE: To quantify the short term respiratory health effects of ambient air pollution in the Paris area. DESIGN: Time series analysis of daily pollution levels using Poisson regression. SETTING: Paris, 1987-92. MEASUREMENTS AND MAIN RESULTS: Air pollution was monitored by measurement of black smoke (BS) (15 monitoring stations), sulphur dioxide (SO2), nitrogen dioxide (NO2), particulate matter less than 13 microns in diameter (PM13), and ozone (O3) (4 stations). Daily mortality and general admissions to public hospitals due to respiratory causes were considered. The statistical analysis was based on a time series procedure using linear regression modelling followed by a Poisson regression. Meterological variables, epidemics of influenza A and B, and strikes of medical staff were included in the models. The mean daily concentration of PM13 and daily 1 hour maximum of SO2 significantly affected daily mortality from respiratory causes. An increase in the concentration of PM13 of 100 micrograms/m3 above its 5th centile value increased the risk of respiratory death by 17%. PM13 and BS were also associated with hospital admissions due to all respiratory diseases (4.1% increased risk when the BS level exceeded its 5th centile value by 100 micrograms/m3). SO2 levels consistently influenced hospital admissions for all respiratory diseases, chronic obstructive pulmonary disease, and asthma. Asthma was also correlated with NO2 levels. CONCLUSIONS: These results indicate that even though the relative risk is weak in areas with low levels of pollution, ambient air pollution, and especially particulate matter and SO2, nonetheless require attention because of the number of people exposed and the existence of high risk groups.

Adolescent↗
PubMed1996

Urban air pollution is still a public health problem in Paris.

By correlating data obtained from environmental indicators and health indicators over a five-year period, a system for measuring the effects of air pollution on health has been established and tested. Rises in air pollution levels do appear to be accompanied by increases in the relevant health problems.

Aged↗
PubMed1995

[Methotrexate pneumonitis arising during the treatment of non-Hodgkin's lymphomas with the m-BACOD protocol].

We retrospectively studied 32 patients treated with the m-BACOD regimen in a single institution between January 1988 and December 1991. After four to seven courses, four patients presented severe acute pneumonitis (PaO2 < 55 mmHg in room air), with diffuse bilateral interstitial syndrome. Broncho-alveolar lavage displayed increased lymphocyte count (> 45%) with inversion of CD4/CD8 in two cases and no evidence of parasitic, bacterial or viral infection. All patients received methyl-prednisolone (0.5 to 1 mg/kg/d x 1 week) with both complete clinical and radiological recovery within a week. The m-BACOD regimen was continued without bleomycine for four patients and without bleomycine plus methotrexate for two patients, until the completion of eight courses, without recurrence of pneumonitis. Drug-exclusion decisions were made empirically because the exact nature of the pneumonitis was not recognized at the time of diagnostic. Because of the regular administration in the m-BACOD regimen, methotrexate leads to an increased risk of pneumonitis. We concluded that the use of the m-BACOD regimen should henceforth be discontinued.

Adult↗
PubMed1993

[Urban atmospheric pollution and mortality: analysis of epidemiological studies published between 1980 and 1991].

This paper analyses 14 epidemiologic investigations (published from January 1980 to September 1991) about the relationship between urban air pollution and mortality. Air pollution indicators and mortality indicators are examined. Methods to analyse the relationships between these two kinds of indicators are classified according as they bring "qualitative information" trying to answer the question: "is there any relationship between air pollution and mortality?" or according as they try to quantify this relationship. Results are presented by author. Confounding factors and means to take them into account are described. This paper ends by a discussion about interest and limits of these studies. It emphasizes the importance of the collaboration between metrologists of urban air pollution and epidemiologists.

Air Pollutants↗
PubMed1992

The in vitro effect of amodiaquine on bone marrow granulocyte-macrophage progenitor cells from normal subjects.

Amodiaquine is used for antimalarial prophylaxis and treatment and has been associated with neutropenia and agranulocytosis in man. The effect of the drug on the in vitro growth of bone marrow human myeloid progenitor cells (GM-CFU) was tested using the soft agar culture technique: 42 haematologically normal subjects were studied and it was found that amodiaquine, at concentrations tested in vitro (0.005, 0.05 and 0.5 micrograms.ml-1), had no quantitative effect on the colony and cluster growth. Our results argue against direct toxicity of the drug on GM-CFU. Therefore, in cases of amodiaquine-associated neutropenia, alternative mechanisms should be considered: a abnormally sensitive GM-CFU; b) toxic effect of metabolites such as desethyl-amodiaquine; c) immune-mediated toxicity.

Adolescent↗
PubMed1989

Toxicity of HPA-23 (ammonium-21-tungsto-9-antimoniate) for normal human myeloid progenitor cells (GM-CFU) in vitro.

HPA-23 is a competitive inhibitor of the RNA-dependent DNA polymerase (reverse transcriptase) of the human immunodeficiency virus (HIV). It may therefore potentially benefit patients with HIV infection. This study aimed at defining the haematopoietic toxicity of this drug and particularly its effects on the normal human granulocyte-macrophage progenitor cells (GM-CFU). Our in vitro studies, in semi-solid agar, have shown an inhibitory effect of increasing concentrations of HPA-23 on colony and cluster formation. This effect is probably dose-dependent. An almost complete inhibition of colony formation was observed at doses of more than 20 micrograms/ml. Regarding cluster formation, a similar although much more progressive inhibitory effect was found. Our experimental data should be extrapolated with caution to clinical situations. However, they must be kept in mind for optimal design of HPA-23 therapy in HIV infected patients.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Amodiaquine-induced agranulocytosis: report of a case with in vitro studies of granulocyte-macrophage progenitor cells.

We report a case of amodiaquine-induced agranulocytosis in a 60-year-old woman. Four months after the agranulocytosis episode we investigated the effect of the drug using in vitro agar culture techniques. Amodiaquine at increasing concentrations (0.005, 0.05 and 0.5 microgram/ml) displayed an inhibitory effect, probably dose-dependent, on the growth of the patient's bone marrow GM-CFU colonies in the absence of autologous serum. In contrast, no effect was found on the colony and cluster growth of bone marrow samples from 13 healthy controls. Though it has been shown in several cases that amodiaquine-induced agranulocytosis occurs via immune-mediated mechanisms, our data are in support of a direct toxic effect of the drug on abnormally sensitive myeloid progenitor cells.

Agranulocytosis↗
PubMedDate not supplied

When world views collide: a commentary on home health care case-mix and patient outcomes.

The Health Care Financing Administration (HCFA) has developed a prospective payment system for home-health care that is primarily focused on cost-containment. This new payment system results in a change in a case-mix for treatment that was more care-outcome based. The new case mix is compared to the old case mix with respect to research that is ignored regarding care outcome.

Aged↗
PubMedDate not supplied

[Realization of an assisted system for medical decision and follow-up in hematologic diseases treated with sequential chemotherapy].

The follow-up of patients treated with sequential chemotherapy in internal medicine departments with special interest in haematology imposes a heavy burden on the entire treating staff. The chances of errors, notably in medical prescriptions and care, are not negligible, and these errors result in iatrogenic complications, readmissions and prolonged stays in hospitals. Designing a medical decision and therapeutic follow-up aid system should be time-saving for the staff and ensure good quality and safe prescriptions as well as reliable therapeutic evaluations and better hospital management. The system described here is developed on 4D Macintosh computer which handles a relational data-base. It includes the data-base, i.e. a knowledge-based system devised by the expert clinician containing "declarative" data and deduced rules which represent the expert's reasoning and determine the action to be taken, and the interface between them. The system easily accepts many parameters, thereby enabling medical knowledge and therapeutic attitudes to be updated.

Decision Making, Computer-Assisted↗