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P Schaffer

Publications and source records attributed to P Schaffer.

At least 19 recordsLinked to original sources
PubMed1998

[Breast cancer: epidemiology, risk factors, screening].

Breast cancer is the most frequent cancer in women: more than 8 to 9% of women will develop a breast cancer during their life and the incidence rate is regularly increasing. Despite therapeutic improvements, breast cancer mortality still remains important and varying according to regions (five years survival: 62 to 80% for the last years). The risks factors analysis shows that a primary prevention of the major risks factors is not yet possible (genetic or endogenous hormonal risk). The chemoprevention is still is discussion and under investigation. For the moment, secondary prevention using screening is the only way to improve survival. The lead-time induced by the screening allows an earlier detection of breast cancers. The randomized trials have demonstrated a significant benefit on mortality and morbidity from breast cancer in women aged 50 to 69. So many countries started regional, pilot or national breast cancer screening programmes using mammography with a 2-year interval and specialized centers.

Adult↗
PubMed1998

Estimation of outward currents in isolated human atrial myocytes using inactivation time course analysis.

The aim was to investigate outward currents in single, isolated, human, atrial myocytes and to determine the relative contribution of individual current components to the total outward current. Currents were recorded using the whole-cell patch-clamp technique at 36-37 degreesC. Individual outward current components were estimated from recordings of total outward current using a mathematical procedure based on the inactivation time course of the respective currents. This method allows estimation of outward currents without the use of drugs or conditioning voltage-clamp protocols to suppress individual current components. A rapidly activating and partially inactivating total outward current was recorded when myocytes were voltage clamped at potentials positive to -20 mV (peak current density 24. 0+/-0.97 pA/pF at +40 mV; n=107 cells, 33 patients). This total outward current comprised three overlapping currents: a rapidly inactivating, transient, outward current (Ito1) a slowly and partially inactivating current (ultrarapid delayed rectifier, IKur) and a third current component which most probably reflects a non selective cation current (not characterized). The average current densities at +40 mV were 8.92+/-0.44 pA/pF for Ito1 and 15.1+/-0.72 pA/pF for IKur (n=107 cells). Recovery from inactivation was bi-exponential for both currents and was faster for Ito1. A slowly activating delayed rectifier current (IK) was not found. The current densities of peak Ito1 and IKur varied strongly between individual myocytes, even in those from the same patient. The ratio IKur/Ito1 was 0.5-6.9 with a mean of 1.98+/-0.11 (n=107 cells), suggesting that IKur is the main repolarizing current. The amplitudes of the total outward current, Ito1 and IKur, and the ratio of the latter two were independent of patient age (16-87 years).

Adolescent↗
PubMed1998

L-type calcium current in human ventricular myocytes at a physiological temperature from children with tetralogy of Fallot.

OBJECTIVE: The aim was to investigate the electrophysiological properties of the L-type calcium current (ICa,L) in ventricular myocytes at a physiological temperature (36-37 degrees C) isolated from children undergoing surgical repair of tetralogy of Fallot. METHODS: ICa,L was recorded with the patch-clamp technique in the single electrode whose-cell mode at a physiological calcium concentration (1.8 mmol/l) at 36-37 degrees C. RESULTS: Under these conditions, maximum current density averaged -5.80 +/- 0.45 pA/pF. ICa,L showed a bell-shaped current-voltage relationship: the current activated at -37.7 +/- 1.36 mV, peaked at +9.41 +/- 1.60 mV and reversed at +57.7 +/- 2.12 mV (n = 17). At +10 mV, time to peak of ICa,L was 5.23 +/- 0.46 ms. Membrane potentials for half-maximal steady-state activation and inactivation of ICa,L were -6.02 and -20.4 mV, respectively, the slope factors were 7.16 mV for steady-state activation and 6.49 mV for steady-state inactivation. ICa,L did not completely inactivate and showed a big window current between -45 and +40 mV. The inactivation of ICa,L showed a biexponential time course with a fast time constant ranging from 9.11 to 12.9 ms and a slow time constant ranging from 60.9 to 220 ms between -30 and +30 mV. Only the slow time constant showed a pronounced voltage dependency. The recovery from inactivation of ICa,L was biphasic with a fast time constant of 60.7 ms and a slow time constant of 619 ms. beta-Adrenergic stimulation with isoprenaline (1 mumol/l) increased the ICa,L density from -5.71 +/- 1.55 to -13.8 +/- 1.96 pA/pF (142%; P < 0.05) at +10 mV. CONCLUSIONS: The present study demonstrates that most of the electrophysiological properties of ICa,L in ventricular myocytes isolated from children with tetralogy of Fallot resemble those of adult ventricular cells. The existence of a big calcium window current could be involved in the occurrence of early afterdepolarizations which could lead to the high incidence of arrhythmias after surgical repair of tetralogy of Fallot.

Adrenergic beta-Agonists↗
PubMed1998

[Determinants for choice of medical management in the Bas-Rhin].

UNLABELLED: It has already been established that the social origin and the demographic factors have an influence, among other things, on medical practice. What about it in the Bas-Rhin? Our survey's objective consists of emphasising on what motivates the choice of the type of medicine. METHOD: Phone survey on a representative sample of 1010 persons aged between 25 and over 64, residing in the Bas-Rhin. RESULTS: Participation has been of 66.3%. Among participants, there are 49.1% of men and 50.9% of women. 9 among 10 participants state that they have a family doctor. More women claim they are more likely to see a homeopathic doctor and/or a professional of alternative medicine. 8 among 10 persons have their blood pressure checked. 50.9% of participants have a blood analysis made in order to determine their cholesterol level. Building on these medical practices, several groups have been created. 54.1% of participants belong to the same group, having in common the facts of having a family doctor, having their blood pressure checked, and never seeing a professional of alternative medicine. The female participants are properly followed up on the gynecological point of view. Only 29 among 500 women have never had a cervical smear done. The carrying out of a mammography raises with age. When fearing a potential cancer, the first step taken by 56.2% of participants consists of seeing a generalist doctor, whereas 65.9% would prefer going to the hospital to perform further tests. As far as treatment is concerned, 76.8% of them would rather go to a specialised department, even if it is located far from their home. Special attention is to be paid to the fidelity of the population of the Bas-Rhin toward their family doctor. He represents the main link of information between the patient and the prevention policies that have been implemented over the last years.

Adult↗
PubMed1998

[Evaluation of the delays in treatment of myocardial infarction. Results of a survey in Alsace].

In order to assess the conditions of access to emergency care of acute myocardial infarction in Alsace, the authors carried out a survey in all hospitals and medical clinics in the region. All subjects admitted for acute myocardial infarction in the region between 3rd December 1995 and 3rd April 1996 were included. The study population comprised 405 persons. The onset of symptoms usually occurred at the patient's home (85% of cases). The first call was made to the general practitioner in 65% of cases. The emergency ambulance transported 40% of patients. The median time to hospital admission was 5 h 15 (average 21 h); the delay was greater in patients over 65 years of age (6 h 42 versus 3 h 51, p < 0.01). This mainly resulted from a delay in calling the doctor by the patients. Thirty nine per cent of patients underwent a myocardial revascularisation procedure (thrombolysis: 27%, direct coronary angioplasty: 12%). Therefore, ten years after a similar study, this survey shows that the delay to hospital admission has not improved and is still too long for effective emergency therapy to be given. In a region where ischaemic heart disease accounts for 10% of all deaths, a multidisciplinary approach is required to elaborate a regional policy for optimising the management of acute myocardial infarction.

Age Factors↗
PubMed1998

[Influence of knowledge relative to cancer on prevention behavior in the population of Bas-Rhin].

The tendency today is to make the population more aware of health in order to encourage their use of prevention activities. The aim of our telephone survey which was performed on a representative sample of the population (1,010) in the Bas-Rhin department in France, was to study the relationship between the level of knowledge of cancer and the use of screening techniques to prevent it. Eighty-two percent of the males and 78% of the females surveyed, show a profound understanding of cancer in general, the associated risk factors and its prevention. The level of awareness of males did not influence a specific behaviour (p = 0.68) towards cancer prevention. It was shown that in smokers, the more they smoke, the more they underestimate the chances of cure from all categories of cancer (p = 0.01). They both overestimate the number of cigarettes needed daily before smoking becomes toxic (p < 0.01) and are less active physically than nonsmokers (p < 0.007). Heavy smokers live in larger communities (p < 0.02) and smokers are younger than non-smokers (p < 0.0001). In the female population, the level of awareness did indeed influence their behaviour towards cancer prevention (p < 0.04). The level of knowledge was higher in both those who consciously attend cancer screening clinics (cervical Papanicolaou smears and faecal tests) and those who are opposed to faecal tests. Younger females are significantly less aware than those who are older (p = 0.0001) and more than two-thirds of these would not consider a cervical Papanicolaou smear as a preventative diagnostic tool. Females who conscientiously attend cancer screening clinics and who are very much aware of cancer, are generally older in age (p < 0.05). The occurrence of mammography as a preventative measure is both high and dependent on age. In conclusion, the level of knowledge of cancer cannot explain alone human behaviour towards the prevention of this disease. Other determinants responsible for influencing human behaviour towards cancer prevention will be better understood once the social sciences, epidemiology and anthropology units work together and combine resources to achieve a common goal.

Adult↗
PubMed1998

[Can we and must we organize cervical cancer screening in France? Results of the pilot project "EVE" in the department of Bas-Rhin].

EVE is a pilot project for cervical cancer screening whose aim is to test the feasibility of organized screening in the French liberal health system with a consensus of medical participants. After three and a half years, 74.8% of women aged 25 to 64 had had at least one smear. Coverage varies with age, from 89% between 25 and 29 to 56% between 55 and 60. Only 8% of smears are taken by General Practitioners. There is a tendency to space out smears because only 14% of women had had a second smear within one year and 41.1% within 2 years. On the other hand more then 20% percent of women do not return after 3 years. Pathological smears represent 1.94% of all smears. For these, a questionnaire is sent to the physician in order to get information on follow-up. This enables cytologic/histologic correlation. The histologic exam reveals a pathological lesion in 95% of cytologies consistent with invasive cancer, 91% of those consistent with high grade lesions and 70% of those consistent with low grade lesions.

Adult↗
PubMed1997

Descriptive epidemiology of cerebral gliomas in France.

BACKGROUND: Descriptive epidemiology of cerebral gliomas has recently been the subject of several studies, indicating a possible increase in brain tumor rates, particularly in the elderly population. METHODS: Between 1983 and 1990, 1376 registered patients with diagnoses of malignant astrocytomas, low grade astrocytomas, oligodendrogliomas - mixed oligoastrocytomas, and tumors without histologic confirmation were reviewed in 6 French cancer registries. The incidence rates by histologic type, age, and gender were calculated. The variation of the incidence between 1983 and 1990 was also analyzed. RESULTS: The highest incidence was observed in the malignant astrocytoma group (2.38/100,000/year) followed by the low grade astrocytoma group (0.54/100,000/year) and the oligodendroglioma - mixed oligoastrocytoma group (0.25/100,000/year). A significant male predominance was observed in the malignant astrocytoma group (male/female [M/F] ratio of 1.59; P < 0.001) and in the group without histologic confirmation (M/F ratio of 2.6; P = 0.008). Between 1983 and 1990, an increasing trend of 5% per year was observed in the incidence of malignant astrocytomas in the population older than 65 years. CONCLUSIONS: These data confirm the observation made in other countries that the incidence of primary brain tumors (particularly malignant astrocytomas) is increasing in elderly patients.

Adolescent↗
PubMed1997

The pacemaker current I(f) in single human atrial myocytes and the effect of beta-adrenoceptor and A1-adenosine receptor stimulation.

1. We used single human atrial myocytes to study I(f) occurrence, properties and pharmacological modulation. Cells were obtained by chunk enzymatic digestion from samples of right atrial appendages of patients undergoing corrective cardiac surgery. 2. Patch-clamped cells in the whole-cell configuration were superfused with a modified Tyrode solution to reduce contamination by interfering currents and to amplify I(f). The average cell membrane capacitance was 85.06+/-2.41 pF (n=531). Data were consistent with the geometrical dimensions of the cells (length 94.2+/-1.89 microm, width 17.9+/-0.42 microm, n=126). 3. When hyperpolarizing to -120 mV from a holding potential of -40 mV, 252 of 306 tested cells (82%) expressed a hyperpolarization-activated inward current (I(f) density=3.77+/-0.25 pA pF(-1)); the current was considered to be present in a given cell if its density at -120 mV was larger than 0.5 pA pF(-1). 4. Current activation was sigmoidal and fitted a Boltzmann model; the average activation curve (n=25) showed a maximum current amplitude of 205.97+/-19.94 pA, corresponding to 3.87+/-0.63 pA pF(-1), voltage of half-maximal activation (V(1/2)) at -86.68+/-2.19 mV and a slope of -11.39+/-0.69 mV. The reversal potential of I(f) measured by tail-current analysis was -13.07+/-1.92 mV (n=6). The addition of CsCl (5 mM) fully and reversibly blocked the current. 5. In the presence of the beta-adrenoceptor agonist isoprenaline (Iso, 1 microM), V(1/2) was significantly shifted toward less negative potentials by 6.06+/-1.96 mV (n=16, P=0.0039). The selective A1-adenosine receptor agonist cyclopentyladenosine (CPA, 1 microM) caused a statistically significant shift of V(1/2) toward more negative potentials with respect to the control curve, both in the absence (-7.37+/-1.83 mV, P=0.0005, n=11) and in the presence of 1 microM Iso (-4.97+/-1.78, P=0.031, n=6). 6. These results demonstrate that a current with the properties of I(f) described in cardiac primary and secondary pacemakers occurs in the majority of human atrial cells. While the pathophysiological relevance of I(f) in human atrial tissue remains to be defined, our data clearly show that it is modulated through stimulation of beta-adrenoceptors and A1-adenosine receptors.

Adenosine↗
PubMed1997

Cancer incidence and mortality in France in 1975-95.

The aims of the European Network of Cancer Registries (ENCR) are to improve the quality, comparability and availability of cancer registry data in Europe. This paper on cancer incidence and mortality in France presents the most recent available data, with short-term projections to 1995, and a commentary based, where possible, on epidemiological research carried out in France. Cancer incidence in men in France increased throughout the study period 1975 to 1995, from 92,000 new cases in 1975 to about 135,000 in 1995. This increase was partly due to the ageing of the French population, but incidence rates have also increased, particularly from 1975 to 1985. The trend appears to be levelling off in the 1990s, with an incidence rate in 1995 of about 482 per 100,000 (this and subsequent rates quoted are standardized to the European Standard Population). Among women, the all-cancer incidence rates also increased during the 1970s and 1980s. Although the rate of increase was less pronounced than in men, the trend is continuing in the 1990s. The estimated age standardized rate in 1995 was 309 per 100,000, representing 104,000 new cases. The main components of these changes in the last decade were, for men, increases in large bowel and prostate cancer, which have been partly compensated for by decreases in oral cavity, larynx and stomach cancer. For women the trend was dominated by the continuing increase in breast cancer with increases also in large bowel and lung cancers. Of the numerically important cancers in women, only stomach cancer has shown a clear decline. The situation in 1995 was that breast cancer remained the predominant cancer affecting women in France, accounting for almost one third of all new cases of cancer diagnosed and one fifth of cancer deaths. The next most frequent cancers in women were those of the large bowel. Regrettably, incidence rates of both breast and bowel cancer are increasing in women. For men in France the most frequent cancers in 1995 were those of the prostate, large bowel and lung, all of which increased in incidence since 1975. Although it is estimated that there will be more newly diagnosed cases of prostate cancer than lung cancer in 1995, the latter will cause many more deaths, particularly of young men.

Female↗
PubMed1997

Transcranial Doppler echo contrast studies using different colour processing modes.

OBJECTIVES: To study the effects of different colour imaging modes on the contrast-medium-enhanced image of the intracranial cerebral arteries. METHODS: Twelve healthy volunteers were studied transcranially after administration of 10 ml BY963 successively with Power Doppler (p-TCCS) and with colour Doppler frequency imaging mode (f-TCCS) in a randomized order. RESULTS: The latency time (mean+/-SD) from the injection until the signal enhancement in the middle cerebral artery was 17.1+/-5.8 s for p-TCCS and 17.8+/-4 s for f-TCCS, and the duration of the optimal diagnostically useful signal enhancement was 44.2+/-8.2 s and 40.2+/-12.6 s respectively. CONCLUSIONS: Based on the measured parameters, both imaging modes were of equal value. Theoretical differences in sensitivity of the two methods play no particular role facing the immense signal enhancement after echo contrast application.

Adult↗
PubMed1997

Characteristics of transcranial Doppler signal enhancement using a phospholipid-containing echocontrast agent.

BACKGROUND AND PURPOSE: Ultrasound attenuation caused by the skull is a major limitation of transcranial Doppler. Echocontrast agents (EAs) may solve this problem. The aim of the present study was to investigate the characteristics of a new echocontrast agent (BY963) containing air bubbles stabilized by phospholipids. METHODS: Nine healthy volunteers received three different doses (2.5, 5.0, and 10 mL) of BY963 at an injection rate of 0.25 mL/s. The Doppler signal amplitude obtained from the middle cerebral artery was recorded with a 2-MHz pulsed-wave Doppler system. After complete decay of the signal enhancement, upward stroking of the veins of the upper arm was performed to evaluate the stability of the EA in the venous system. RESULTS: A dose-dependent increase of at least 30 dB in the Doppler signal amplitude lasted 19 to 47, 35 to 64, and 48 to 126 heart cycles (68% range) after 2.5, 5.0, and 10 mL EA, respectively. In 6 cases, there was a biphasic increase in EA enhancement. Upward stroking of the forearm, in general 12 to 18 minutes after administration, caused a Doppler signal enhancement of at least 30 dB in 6 cases. CONCLUSIONS: Each injection of BY963 caused a diagnostically relevant Doppler signal enhancement. A considerable amount of EA remained stable in the venous system for at least 12 minutes. The biphasic dose-response fits to models of dilution-indicator theory and indicates free recirculation, as well as a nonlinear washout curve.

Adult↗
PubMed1997

[Digestive cancers in France. Geographic distribution and estimation of national incidence].

OBJECTIVES: The purpose of this study was to compare the incidence of digestive cancers in 9 French departments and to give an estimate of this incidence for the whole of France, based on this data. METHODS: This study focused on the 1983-1987 period. The record quality for the 9 included registries (Calvados, Côted'Or, Doubs, Haute-Garonne, Hérault, Isère, Bas-Rhin, Somme, Tarn) has been assessed by the National Committee of Registries. The crude incidence rates and those standardized according to the world population have been worked out per localization and per sex. Incidence and mortality rates per department as well as mortality rates for the whole of France have enabled the assessment of the incidence and number of new digestive cancer cases per year. RESULTS: Esophagus and liver cancers are distinguished by large incidence disparities, fluctuating in a ratio of 1 to 5, and by a high sex ratio. In other localizations, incidence rates vary in a ratio of 1 to 2. The incidence rates of digestive cancers were especialy high in the Bas-Rhin department. They tended to be higher in Côte-d'Or, Doubs, Calvados and Somme, than in Haute-Garonne. Hérault and Tarn. The estimated number of digestive cancers was 30,071 in males and 19,951 in females: colorectal cancer was particularly frequent, 14,179 cases and 12,228 cases, respectively. CONCLUSION: There are some geographical variations, from one region to another, in digestive cancer incidence in France more pronounced for esophagus and liver cancers than for other localizations. Because of its frequency, colorectal cancer represents a serious problem for public health.

Adolescent↗
PubMed1997

Mass screening programs for breast cancer in France--average values of assessment criteria.

Breast cancer is the most common cancer in women worldwide. Many studies have been performed worldwide to assess the effectiveness of screening in terms of reduced mortality due to breast cancer. Since the end of 1989, 10 breast cancer mass screening programs using mammography have been carried out in France under the sponsorship of the National Fund for Health Prevention, Education, and Information (FNPEIS) from the National Health Insurance of Salaried Workers (CNAMTS). These 10 campaigns, which are on a district scale, are organized according to variable methods and are assessed using a common procedure. Four groups of criteria are measured in this procedure, which investigates the impact, quality, effectiveness, and costs of screening programs. The average and extreme values of each criterion as calculated from the campaigns are presented in this paper. In order to enlighten the judgment on the French results, a comparison with the international standards in force and with the results of foreign screening programs is proposed.

Aged↗