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Biomedical subjects

P Schaffer

Publications and source records attributed to P Schaffer.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Epidemiology of cervical and endometrial cancer].

In 1995, in France, the estimation of the cervix cancer incidence, with 3,300 new cases, is of 10.3 per 100,000, and the incidence of the endometrial cancer with 3,268 new cases, is of 13.8 per 100,000. The decrease of the incidence of the cervical cancer is of more than 50%, in 1975, the incidence was of 22.4 per 100,000. For the endometrial cancer, the decrease is insignificant, as in 1975, the incidence was of 14.4 per 100,000. This phenomenon has been observed in most european countries. The incidence of the adenocarcinoma of the cervix remains stable. The relative survival at 5 years, at all ages in the French cancer registry of Bas-Rhin is of 65% for the cervical cancer and of 73% for the corpus uteri cancer. However, no improvement has been observed since 1975. The risk factors are quite well-known concerning the cervical cancer, there is a strong correlation with the sexual activities, age at first intercourse, the multiplicity of the partners, which clearly shows that the cervical cancer is a sexually transmitted disease. Concerning the endometrial cancer, the risk factors are mostly linked with the reproductive life: age at menarche, parity, age at first birth, menstrual irregularities, infertility and menopause.

Adult↗
PubMed1997

[Screening of cervical cancer, an action of public health, a problem of society].

Well organized, the cervical cancer screening is very efficient and theoretically allows a decrease of the cumulative incidence of 93.5% if smears are taken each year, and 90.8% if it is taken every three years. However, this screening is regularly controversed concerning the age of the target population and the frequency of the smear. It is important that the health authorities are aware that the screening can only be justified if well managed, well evaluated, and endowed with a quality insurance system. In France, the conditions of an efficient screening are not gathered. The practitioners should have a minimum education in public health in order to be able to understand well that screening does not obey the same ethical, deontological rules and organization that the curative medicine. Imposing a high frequency of the smear has deleterious effects on women and is responsible of a bad use of the resources.

Female↗
PubMed1996

Effects of the class III antiarrhythmic drug ambasilide on outward currents in human atrial myocytes.

We have studied the inhibitory influence of the class III antiarrhythmic drug ambasilide (LU 47110) on the transient outward current Ito1 and the sustained current Iso following inactivation of Ito1, in human atrial myocytes. The two currents are separated by a mathematical procedure based on the amplitudes and time constants of the biexponential inactivation of the total outward current. The frequency dependence, the recovery from inactivation and the kinetics of activation and inactivation are described. Ambasilide reversibly and concentration dependently inhibited Ito1, Iso and the sodium current INa. Concentration required for half maximal inhibition (IC50) for the effects on Ito1 and Iso were 23.3 mumol/l and 45.7 mumol/l respectively, concentrations shown by others to be effective in terminating and preventing fibrillation in a dog atrial arrhythmia model. Ambasilide not only reduced the amplitude of Ito1 and Iso but also accelerated the time course of inactivation from 14.22 to 6.69 ms and from 202.3 to 87.9 ms respectively. The amplitude of Ito1 showed only a small dependence on stimulation frequency characteristic for human atrial myocytes, whereas Iso was reduced significantly at higher stimulation frequencies. Ambasilide did not change these relationships (0.1-4 Hz) and therefore did not show the reverse use-dependence known from other class III antiarrhythmic agents and which is an important property for a prospective antiarrhythmic drug. The lack of an effect of ambasilide on both steady-state activation and inactivation of Ito1, and the time constant of recovery from inactivation, suggests that ambasilide acts by changing conductance rather than by influencing the gating mechanism. The described characteristics make ambasilide an interesting substance in the group of class III antiarrhythmic drugs.

Aged↗
PubMed1996

Multiple primary cancers and estimation of the incidence rates and trends.

The use of different registration rules from one registry to another, both generally and also for paired organs, leads to variations in the proportion of multiple primary cancers: in men, from 0.4 to 4.9% for the colon, 0.1 to 2.7% for the lung, and 4.1 to 8.6% for the mouth and pharynx. Subjective factors, often impossible to verify, contribute to these variations. The impact on the estimation of incidence rates and trends is not negligible for cancers of the mouth and the pharynx and for all the cancers taken together. The trend towards an increase of cancers of the mouth and pharynx in the Bas-Rhin disappeared when the incidence was expressed taking only the first cancer (incidence by individual) into consideration, and the differences in incidence between the Calvados and the Bas-Rhin registries for the same site also disappeared. In the absence of harmonisation of the rules and methods followed for registration, incidence by individual is the only approach which makes it possible to compare incidence rates and trends between registries.

Breast Neoplasms↗
PubMed1996

Childhood leukaemia in Europe after Chernobyl: 5 year follow-up.

The European Childhood Leukaemia - Lymphoma Incidence Study (ECLIS) is designed to address concerns about a possible increase in the risk of cancer in Europe following the nuclear accident in Chernobyle in 1986. This paper reports results of surveillance of childhood leukaemia in cancer registry populations from 1980 up to the end of 1991. There was a slight increase in the incidence of childhood leukaemia in Europe during this period, but the overall geographical pattern of change bears no relation to estimated exposure to radiation resulting from the accident. We conclude that at this stage of follow-up any changes in incidence consequent upon the Chernobyl accident remain undetectable against the usual background rates. Our results are consistent with current estimates of the leukaemogenic risk of radiation exposure, which, outside the immediate vicinity of the accident, was small.

Child↗
PubMed1996

[The role of cancer registries in the evaluation of breast cancer screening].

Cancer registries are necessary to evaluate the efficacy of cancer screening programmes. They provide early indicators of screening efficacy, needed to correct certain campaign failings without waiting for the mortality data, available only 7 to 10 years after the beginning of the screening. They allow to mesure the screening effect not only on the screened women, but also on the entire target population. They also allow to mesure the negative and deleterious effects of the screening. Finally, they are essential to all cost/efficacy study. The evaluation of the breast cancer screening programme in the French department of Bas-Rhin by the cancer Registry showed very quickly the interest of the mesures concerning the quality assurance programme and to estimate on the first screen results basis, that it will be difficult to reduce the mortality by breast cancer to 25%.

Aged↗
PubMed1996

[Therapeutic management of myocardial infarction: trends observed in the MONICA-France project between 1985 and 1991].

This paper describes the trends observed in the treatment of myocardial infarction within the three French MONICA registers between 1985 and 1991. Data, collected according to the WHO-MONICA Protocol, relate to the initial care of patients and the treatment they were prescribed. In this study 2974 cases are included. The time delays before hospitalization do not change in spite of an increasing use of mobile emergency care units. In all three centers there is a strong progression of thrombolysis, increasing from 12% to 41% in Strasbourg, from 21% to 47% in Toulouse and from 31% to 35% in Lille. Antiplatelet drugs rise from 11% to 76% in Strasbourg, from 39% to 85% in Toulouse and from 33% to 76% in Lille. Beta-blockers also progress in the three centers. Prescription of anticoagulants, nitrates and antiarrythmics is constant. In contrast calcium blockers are less prescribed. Duration of hospital stay is much longer in Strasbourg. In Toulouse the resort to coronary angiography (96%) and to angioplasty (51%) is much more frequent than in the two other centers. Similar trends in the three regions reflect the results of the secondary prevention trials conducted in the last years. Differences concern mainly treatments and procedures that were less studied before 1991. It will be interesting to study the trends in the following years in order to estimate the influence of the trials on the homogeneity of practice in the three centers.

Adult↗
PubMed1995

Adenosine inhibits the L-type calcium current in human atrial myocytes.

The effects of adenosine on the L-type Ca2+ current (Ica) were studied in human atrial myocytes using the whole-cell voltage clamp technique. Ica was recorded under physiological calcium concentrations (1.8 mmol/l) at 37 degrees C. Under these conditions the current density of basal Ica averaged 4.0 pA/pF. Isoprenaline (1 mumol/l) increased basal Ica to 249.7%. Adenosine (100 mumol/l) in the presence of isoprenaline (1 mumol/l) decreased Ica from the level obtained with isoprenaline to 87.5% of basal Ica. Adenosine (0.1 to 100 mumol/l) also reduced basal Ica, maximally to 64.5% of control. Activation and inactivation parameters of basal Ica were not significantly different between adenosine (100 mumol/l) and control recordings. Our results show that adenosine affects both basal and isoprenaline stimulated Ica in human atrial myocytes. Although a considerable decrease of basal Ica was seen, we conclude that the action of adenosine on L-type Ca2+ current in human atrial myocytes is mainly antiadrenergic. Both effects may contribute to the antiarrhythmic properties of adenosine.

Acetylcholine↗
PubMed1995

Optical multisite monitoring of cell excitation phenomena in isolated cardiomyocytes.

An especially designed setup which consists of an inverted fluorescence microscope, an argon ion laser and a photodiode array system permits membrane potential monitoring in isolated guinea-pig ventricular cardiomyocytes, stained with the voltage-sensitive dye di-4-ANEPPS, which responds linearly with relative fluorescence changes (delta F/F) approximately -8% per 100 mV. About a dozen measuring spots covering a single cell were simultaneously monitored with a spatial and temporal resolution of 15 microns and about 20 microseconds, respectively. In general, the rising phases of the action potentials within a single cell were highly synchronized (i.e. all upstroke velocities peaked within about 20 microseconds); however, in one cell (out of 25 examined) significant (P < 0.05) time lags exceeding the signal-dependent time resolution were also found. Experiments, simultaneously performed with our optical system and a widely used patch-clamp setup, revealed a slowed and delayed response of the clamp amplifier depending on the cell access resistance. Optical monitoring during whole-cell voltage-clamping demonstrated the influence of graduated series resistance compensation. When field stimulation was used, our results clearly demonstrated the spatially dependent polarization of the cell membrane during the stimulus, as well as a highly synchronized upstroke development. Slight differences in the maximum upstroke velocities within a single cell were also found and were basically in agreement with mathematical models.

Animals↗
PubMed1995

Mortality from cardiovascular diseases among potash miners exposed to heat.

We assessed mortality rates in a cohort of French potash miners between 1977 and 1987. The cohort comprised all workers of a potash mine active on January 1, 1977, or subsequently hired, with at least 3 years of employment. We compared the mortality of the subcohort exposed to heat from underground work (U) with the mortality of those who had never worked underground (D). The overall mortality was low [standardized mortality ratio (SMR) = 0.89, based on 570 deaths] and was lower among underground workers (age-standardized mortality rate = 660 per 100,000 person-years, 266 deaths) than among daylight workers (age-standardized mortality rate = 710 per 100,000 person-years, 304 deaths). Mortality from ischemic heart diseases (IHD) was higher for underground workers than for daylight workers (relative risk = 1.6). As exposure to heat decreased over time, we analyzed the mortality according to period of hire: within underground workers, we observed a downward trend for mortality from IHD which contrasted with a stable mortality from IHD among daylight workers. Among subjects who left for medical reasons, IHD mortality was five times greater in the heat-exposed group compared with daylight workers. The data are consistent with an increased risk of ischemic heart diseases from a hot environment that is offset by a strong healthy worker effect.

Cardiovascular Diseases↗
PubMed1995

Phase I: transcranial echo contrast studies in healthy volunteers.

BACKGROUND AND PURPOSE: Transcranial ultrasound diagnostics are particularly hindered by insufficient ultrasound penetration through the temporal bone. The use of ultrasonic contrast media to enhance the Doppler signal is an important step toward the solution of this problem. In the present study we investigated the tolerability and the diagnostic value of a new intravenous transpulmonary ultrasonic contrast medium, BY963. METHODS: In two phase I studies, 8 healthy volunteers received a spherosome suspension containing a phospholipid as the active ingredient. The intravenous injection was performed in three doses (2.5, 5, and 10 mL) at four different injection rates (0.25, 0.5, and 1 mL/s and bolus). The duration and degree of the signal enhancement were measured by two transcranial ultrasonic procedures presently used in clinical practice: transcranial Doppler sonography (TCD) and transcranial color-coded sonography (TCCS). The assessment of tolerability was based on chemical laboratory parameters and hemodynamic data (heart rate, blood pressure, electrocardiogram) and on questionnaires relating to general well-being. RESULTS: BY963 was tolerated without complications. All 38 administrations of the echo contrast medium produced a marked increase in the TCD signal (> 30 dB) in the intracranial basal cerebral arteries. To obtain the optimum time window for diagnostic use, higher doses with slower injection rates are advantageous. The duration of optimal contrasting was 42 to 68 seconds (TCD) and 12 to 132 seconds (TCCS), depending on the method and mode of administration. Bolus injections gave rise to an increased incidence of color artifacts. CONCLUSIONS: BY963 significantly improves intracranial Doppler imaging while being well tolerated. The signal enhancement lasts long enough for TCCS to display all basal cerebral arteries after just one injection.

Adult↗
PubMed1995

[Public health problems related to chemoprevention of cancers].

The chemoprevention sets down numbers of problems and requires certain number of conditions. First of all, one has to demonstrate the action's effectiveness by a randomised trial using the appropriate effectiveness indicators and to confirm the results of the trial by a pilot prevention's project. The action shouldn't have neither inconvenient nor major risks. In numerous prevention's action, the inconvenient are superior to the benefits. The action should be aware of respecting the major ethical aspects: respect the person's autonomy, don't to be harmful, respect the equity and be beneficial; it also has to avoid important psychological consequences. At last, the prevention's action has to appeal to cost effectiveness strategy.

Antineoplastic Agents↗
PubMed1995

[Role of cancer registries].

The first Cancer Registries were created in 1975 in France. Their ulterior development and their scientific production have been furthered by the apparition from 1986 under the aegis of the Health Ministry and of the INSERM, of a National Population Registry Committee. Cancer Registries have seriously contributed to a better knowledge of the cancer problem in our country and to describe the french specificities, in particular the importance of the mouth and pharynx cancers. They insure both a monitoring and an alert role; they also contribute to the medical supervision of the Chernobyl accident effects. French registries play a very active role concerning clinical research. They participate to many European studies of health care evaluation. In other respects, many etiological studies have been realized about professional risks of cancer, risks linked with nutritional habits, and on the etiologic role of the Tamoxifen. Finally, certain registries have created DNA banks. If nowadays their role in health planning remains modest, they very actively contribute in evaluating screening actions of breast, cervix and large bowel cancers. They also attracted the attention of Health Authorities on the cervix cancer screening's incoherencies. They evaluate the pilot project of the breast cancer and the registry of the Côte d'Or country evaluates the efficacity of a randomized colo rectal mass screening study. The main difficulties met by the registries are linked with the development of laws protecting more and more the individual freedoms, making it harder and harder the registration exhaustive character.

Ethics, Medical↗
PubMed1995

[Ovarian carcinomas. Retrospective study of 318 cases].

OBJECTIVE: Evaluate the diagnosis of cancer of the ovary over time and histological type as a function of outcome. METHODS: Primary neoplasms of the ovary diagnosed at the Pathology Institute of Strasbourg between 1975 and 1984 were reassessed to determine the outcome as recorded in the Bas-Rhin Cancer Register. RESULTS: Among the 845 primary neoplasms diagnosed, 318 were carcinomas. More than half of the cases (n = 162) were serous carcinomas followed by mucinous carcinoma (n = 60), endometrioid carcinoma (n = 53), clear-cell carcinoma (n = 13), and poorly differentiated carcinoma (n = 30). Diagnosis was consistent with time and independent of the pathologist. The patients were divided into three groups on the basis of survival. Longest survival was observed in patients with mucinous and endometrioid carcinoma, intermediary survival in those with serous and clear-cell carcinoma, and shortest survival in those with poorly differentiated carcinoma. CONCLUSION: The histological type of ovary carcinoma, independent of the stage of invasion, is a reliable predictive factor.

Adult↗
PubMed1995

Prognostic factors in CAPD patients: a retrospective study of a 10-year period.

A prognostic study was retrospectively performed on a cohort of 201 ESRD patients having started CAPD in one single centre between 1983 and 1993 (mean follow-up 24 months). At the end of the study 74 patients had died, 63 were transplanted, and 19 had been transferred to another dialysis modality. The purpose of the study was to estimate patient and technique survivals according to clinical and biological variables recorded at the beginning of the treatment. The authors decided to focus on the possible prognostic role of urea kinetic parameters which are still controversial in the literature. Concerning patient survival, the Cox proportional hazards model selected seven prognostic factors, including urea Kt/V (relative risk = 1.69). The division of the study group according to three levels of Kt/V (< or = 1.7, between 1.7 and 2.2, and > 2.2) allowed us to estimate 1.7 as an index of an adequate CAPD prescription. NPCR at the limit of significance for patient survival was clearly a prognostic factor for technique survival (relative risk = 2.50). Creatinine clearance was closely linked to both technique and patient survival (relative risk > 3). These three factors, in addition to the clinical and biological variables generally described in the literature, must be taken into account in the evaluation of a prognosis for CAPD.

Adolescent↗