[Patterns of prescription and usage of triptans in Alsace (France): misuse is frequent and avoidable]. / Modes de prescription et de consommation des triptans en Alsace: un mésusage fréquent mais évitable.

AIMS: To analyze use of triptans in the Alsace region of France: patients, disorders motivating, doses, analgesics and migraine prophylactics associated treatments, contra-indications. To study major consumers (more than 144 intakes per year) and to determine among them the proportion who suffering from chronic headache. METHOD: Data concerning all prescriptions of triptans and analgesics as well as migraine prophylaxis prescriptions were obtained from the computer databases of five of the French National Health's local health agencies in Alsace, recorded between April 1, 2003 and March 31, 2004. Data about motivating disorders and the clinical context were obtained using a questionnaire sent to prescribers. Data about patients with more than 144 intakes per year were provided by medical advisors of French Health insurance. RESULTS: We founded 20686 users: 92.1 percent used between 0 and 6 intakes per month. 11.5 percent of disorders motivating the prescription that were mentioned by prescribers were for off-label use: tension-type headache 2.7 percent, mixed headache, 8.8 percent. Prescribers declared at least one contra-indication for triptan use for 7.8 percent of patients. Over all, prescriptions were off-label for 16.1 percent of patients. Patients who used more than 144 intakes per year accounted for 1.9 percent of the total number and self-medication accounted for 19.2 percent of all triptan intakes. Half of the patients were suffering from daily chronic headache (chronic migraine in 66 percent). 15.6 percent of these patients presented at least one contraindication (high blood pressure or ischemic disease). All in all we estimate that use of triptan is a misuse for 25 percent to 30 percent of the intakes. Quantities of other analgesics used increased simultaneously with triptan use: on average 65, 119 and 244 Defined Daily Doses (DDD)/person/year for patients who used between 1 and 72, 73 and 144 and more than 144 intakes respectively. On average 35.4 percent (in DDD) of analgesics used were opiates (dextropropoxyphene, codeine, tramadol). This proportion increased simultaneously with triptan use: 58.9 percent for major users. Prophylactic treatment for migraine was used by 27.9 percent of the patients: lack of prophylaxis was a prescriber's choice in 90 percent of the cases. CONCLUSIONS: The high rate of triptan misuse emphasizes the importance of improving prescription of these drugs.

[Damage control laparotomy for haemorragic abdominal trauma. A retrospective multicentric study about 109 cases]. / La laparotomie écourtée dans les traumatismes abdominaux hémorragiques. Etude multicentrique rétrospective sur 109 cas.

AIM OF THE STUDY: Damage control laparotomy is a new approach to the more severe abdominal traumas. It stems from a better understanding of the physiopathology of the haemorragic shock. PATIENTS AND METHODS: A national retrospective study from 27 centers about 109 trauma patients who underwent a damage control procedure between January 1990 and December 2001, is analysed. Surgical procedures included 97 hepatic packing, 10 abdominal packing, 4 exclusive skin closure, 1 open laparotomy technique and 3 digestive stapplings. RESULTS: The mortality rate is 42%. Eleven abdominal compartment syndromes have occurred with 7 decompressive laparomy (4 deaths). CONCLUSION: This study is based on the largest series of damage control laparotomy published in France. Results in terms of mortality and morbidity are similar to those of published studies from the USA.

Simultaneous measurements of mobility, dispersion, and orientation of DNA during steady-field gel electrophoresis coupling a fluorescence recovery after photobleaching apparatus with a fluorescence detected linear dichroism setup.

Orientation of molecules is responsible for the loss of separability during steady-field gel electrophoresis. In this work we develop a technique to measure simultaneously the relevant parameters involved in the separation mechanism: electrophoretic mobility, band broadening, and molecular orientation. To do that we have associated a fluorescence recovery after photobleaching (FRAP) apparatus with a fluorescence detected linear dichroism setup. This coupling allows one to follow the buildup of orientation during the FRAP experiment. Because orientation involves a change in the angular distribution of fluorescence, we have added a fluorescence polarization setup which can be used in parallel with the FRAP and gives an exact value of the steady-state orientation factor. We illustrate the possibilities of these combined experiments by analyzing the coupling of electrophoretic transport and orientation of lambda DNA in 1% agarose gels.

Migration of single-stranded DNA in polyacrylamide gels during electrophoresis.

By using fluorescence recovery after photobleaching (FRAP) and electric birefringence, the migration of single-stranded DNA in polyacrylamide gels and orientation as a response to an electric pulse were investigated. Electrophoretic mobility is in good agreement with the model of biased reptation including fluctuations. The determination of the electrophoretic mobility in solution, mu0, allows an estimation of the gel pore diameter seen by the molecule. As previously observed for double-stranded DNA, the electric birefringence results from two processes: the alignment of the molecule along the electric field and the elongation of the primitive path in the gel, for long single-stranded DNA (>2000 bases). The combination of results obtained with the two techniques allows us to propose experimental conditions to improve the separation of single-stranded DNA with pulsed field techniques.

Field and pore size dependence of the electrophoretic mobility of DNA: a combination of fluorescence recovery after photobleaching and electric birefringence measurements.

By combining an electrophoretic cell with a setup of fluorescence recovery after photobleaching (FRAP) we can measure the electrophoretic mobility mu of double-stranded lambda DNA in agarose gel as a function of electric field E and gel concentration C. Mobility varies linearly with the field in agreement with the biased reptation model with fluctuations. The slopes are analyzed in term of orientation and compared with birefringence results. The mobility extrapolated at zero field follows the prediction of the reptation theory; we deduced the variation of the pore size with the agarose concentration. With a special use of our setup, we measure directly the free-mobility mu 0 of the DNA.

Dynamics of DNA molecules in agarose gel under sinusoidal electric fields.

The dynamics of DNA molecules in agarose gel has been studied by measuring the birefringence in sine wave electric fields. It was found that the birefringence is the sum of a direct current (dc) component and several harmonics of the field frequency. A detailed study of these components was performed. It was found that the dynamics of DNA molecules under these conditions can be explained by a W conformation which is not detected under dc electric fields. The variation of the field frequency gives several relaxation modes in the birefringence signal, reflecting the known dynamic behavior of DNA molecules found in the reputation with elongation of the tube length regime.

Dynamics of single-stranded DNA in polyacrylamide gels during pulsed field gel electrophoresis. A birefringence study.

The study of the orientation of single-stranded DNA in polyacrylamide gels in denaturing conditions has been undertaken by electric birefringence in order to determine the mechanism involved in the electrophoretic transport. The presence of an overshoot in the birefringence signal, when applying the electric field, and the study of the influences of the electric field and of the gel concentration on the dynamics show that a mechanism of reptation with elongation of the molecule occurs in polyacrylamide gels with low T values. Therefore it is suggested that the use of pulsed fields in sequencing electrophoresis is possible and can lead to a large increase of the length of the fragments that can be sequenced in one single run.

Electric birefringence of polytetrafluoroethylene particles in agarose gels.

Electric birefringence studies of strongly elongated, rod-like particles of polytetrafluoroethylene (PTFE) in agarose gels show that the negative effect observed by semi-diluted aqueous suspensions at low frequencies and at low electric field strengths (the so called "anomaly') disappears. The absolute value of the low frequency effect increases 3-4 times and the amplitude of modulation decreases faster compared to that of the suspensions. This together with decreased decay relaxation times in gels make the possibilty that the PTFE particles orientation in gels is not due to dipolar but to electrophoretic orientation mechanism quite probable. Similar change in the orientation mechanism could be expected also for suspensions of higher concentrations. The further elucidation of the orientation mechanism using fractions with lower polydispersity, broader ranges of experimental conditions (particle concentration, ionic strength and composition, electric field strengths, frequencies, etc.) could be interest for several fields: colloid electro-optics and especially that of concentrated colloids, pulsed field gel electrophoresis of DNA (and especially its sinusoidal biased field variant) and of nucleoprotein complexes and for the gel research.

Dynamics of DNA under pulsed-field gel electrophoresis as analyzed from birefringence rise and decay.

The orientation of DNA induced by electrophoretic transport in agarose gel has been studied by optical birefringence. From its field-free decay, it is clearly demonstrated that the degree of orientation results from two processes: alignment along the electric field (stretching of the end-to-end vector) and elongation of the primitive path in the gel (overstretching). Separation of the two contributions allows the experimental determination of the effective charge per base pair, the gel pore size seen by the reptating molecule, the reptation time, the degree of overstretching and the mean relaxation time of the overstretching. Their field and DNA length dependences compare well with theoretical predictions. Similarly, the time at which overstretching presents an overshoot in the rise of the orientation follows closely the predictions of a model based on the evolution of J-shaped conformations. The recovery of such conformations is studied by a sequence of two pulses with variable delay time. The use of directly measured or extrapolated characteristic times and fields in the design of efficient pulse schemes for pulsed-field gel electrophoresis is emphasized.

[The tibial slope. Proposal for a measurement method]. / La pente tibiale. Proposition pour une méthode de mesure.

The posterior inclination of the tibial plateaus relative to the longitudinal axis of the bone, also called tibial slope, is important to know for the pathology of the cruciate ligaments and to lay some knee prostheses. We have chosen a reproducible method to measure it, on the basis of a large radiograph of the lower limb. A radio-anatomical analysis of the morphology of the tibia has first been carried out to properly choose axes that are easy to find and useful in practice. The accuracy of the measurement is to within one degree. In adults, the slope ranges from 0 to 18 degrees, according to the subjects, with variations form one knee to the other.

Viscosity and scattering of very weakly charged polyelectrolytes.

Careful examination of the concentration range where both intrinsic viscosity and light scattering show a polyelectrolyte effect, even for singly charged halato-telechelic ionomers in DMF, together with the neutron scattering results at higher concentration show that weakly charged polymers may be a very useful tool to understand the complicated effects of coulombic interaction in polyelectrolyte solutions. A theoretical framework is given for a systematic study of such weakly charged polymers. The current state of understanding is presented of the properties of solutions of strong polyelectrolytes and of charged rigid particles. Finally it is shown how the transposition to weak polyelectrolytes solutions sheds light on the respective contributions of intra- and intermolecular interactions.

[Orientation and stretching of DNA chains during pulsed field gel electrophoresis]. / Orientation et déformation des chaînes d'ADN pendant l'électrophorèse sur gel en champ pulsé.

The quantitative analysis of the decay of birefringence accompanying gel electrophoresis leads to the characterization of two phenomena respectively attributed to alignment of the tube and to overstretching of the chain in its tube. The major contribution to the molecular orientation is given by the overstretching which relaxes according to a stretched exponential law. The other process, slow, is characterized by a reptation time and a mean orientation factor in good agreement with the biased reptation model without overstretching.

A reactor permitting injection and sampling for steady state studies of enzymatic reactions at high pressure: tests with aspartate transcarbamylase.

A high pressure reactor for steady state studies of enzymes is described. It allows injection, stirring, and sampling without release of the pressure (up to at least 400 MPa). Thus, either substrate or enzyme can be injected to initiate an enzyme-catalyzed reaction whose progress can then be followed by measurements on samples taken from the reactor. The dead time of sampling is 10-15 s, which allows reactions with pseudo-first-order rate constants smaller than about 1 min-1 to be monitored. It can be used for any enzymatic reaction; unlike previously described high pressure apparatus, it is not limited to the study of enzymes whose activity can be directly followed by spectrophotometry. The use and reliability of this reactor is demonstrated by tests with aspartate transcarbamylase. The activity of this enzyme is enhanced by pressures of the order of 120 MPa.