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Les fractures-avulsions isolées du tubercule mineur de l’humérus sont rares chez l’adolescent. Trois mécanismes lésionnels sont décrits et la connaissance de leur existence, en combinaison avec un examen clinique complet, sont primordiaux pour un diagnostic précoce. Nous présentons le cas d’un joueur de tennis âgé de 13ans souffrant d’une fracture-avulsion après un « simple » coup droit. Des radiographies et une IRM ont rapidement confirmé le diagnostic. Les fractures-avulsions isolées du tubercule mineur avec un déplacement minimal, un diagnostic précoce et des demandes sportives modérées peuvent obtenir un résultat fonctionnel excellent avec un traitement conservateur. En accord avec la littérature, nous conseillons un traitement chirurgical si le déplacement est majeur, si des lésions tendineuses sont associées, ou si le diagnostic n’est fait qu’au stade chronique.

Background: The world’s epidemic of obesity is responsible for the development of bariatric surgery in recent decades. The number of gastrointestinal surgeries performed annually for severe obesity (BMI > 40 kg/m2) in the United States has increased from about 16,000 in the early 1990s to about 103,000 in 2003. The surgical techniques can be classified as restrictive, malabsorptive, or mixed procedures. This article presents the results for 2 years of bariatric surgery in the authors’ minimally invasive center and analyzes the results of the most used surgical techniques with regard to eating habits. Methods: Between January 2002 and January 2004, the authors attempted operations for morbid obesity in 110 consecutive patients adequately selected by a multidisciplinary obesity unit. This represented 43% of all consultations for morbidly obese patients. The patients were classified as sweet eaters or non–sweet eaters. All sweet eaters underwent gastric bypass. The procedures included 70 Roux-en-Y gastric bypasses, 39 Mason’s vertical banded gastroplasties, and 1 combination of vertical gastroplasty with an antireflux procedure. Revision procedures were excluded. Results: The mean age of the patients was 41.36 years (range, 23–67 years), and 72.3% were female. The mean preoperative body mass index was 44.78 kg/m2(range, 34.75–70.16 kg/m2). The mean operating time was longer for gastric bypass than for the Mason procedure. Three patients required conversion to an open procedure (2.7%). The two operative techniques had the same efficacy in weight reduction. Early complications developed in 11 patients (10%), and late complications occurred in 9 patients (8.1%). The postoperative length of hospital stay averaged 4.4 days (range, 1–47 days; median, 4 days), and was longer in the gastric bypass group. The mortality rate was zero. Data were available 2 years after surgery for 101 of the 110 patients (91%). Most comorbid conditions resolved by 1 year after surgery regardless of the type of operation used. Conclusion: With zero mortality and low morbidity, bariatric surgery performed for adequately selected patients is the most effective therapeutic intervention for weight loss and subsequent amelioration or resolution of comorbidities. The patient’s eating habits before surgery play an important role in the choice of the operative technique used.

In this article we try to show how a social theory can be constructed which takes the requirement of self-implication or autology serious. For this purpose, we turn to Niklas Luhmann's theory of self-referential, autopoietic systems. For it is our thesis that the specific conatus of Luhmann's enterprise is to construct an autological social theory, i.e. a theory which is sufficiently complex to imply itself, to describe itself in the course of describing its objects of investigation. To demonstrate this claim, the line of argument has firmly been rooted in George Spencer-Brown's Law of Forms, a work central to systems theory. The architecture of Luhmann's systems theory is thus presented in accordance with Spencer-Brown's calculus of indications. Special attention is being paid to systems theory's Leitdifferenz system/ environment. For this distinction is literally maintained as the alpha and the omega of the theory: the Leitdifferenz carries theoretical observations, and at the same time permits the self-observation. By means of the figure of 're-entry', drawn from Spencer-Brown's calculus, we show how the starting distinction between system and environment, can 're-enter' the construction founded upon it and makes it possible for the theory to observe itself as a system within an environment.

This paper presents a survey of developments in de novophasing methods and instrumentation in protein crystallography that have been carried out over the past 20 years at the French synchrotron radiation facility LURE. This includes progress in detector technology, particularly with multiwire proportional chambers, contributions to the development of the MAD and MASC methods for experimental phase‐determination viaanomalous dispersion, the exploration of the use of xenon and krypton as heavy atoms and anomalous scatterers, as well as the substantialization of parts of the `Bayesian programme' for structure determination in highly efficient and user‐friendly software. It is shown how the conjunction of high‐quality data collection with novel phasing methods and with optimized data‐processing schemes can bring about major improvements, even when the signal is very weak, in the accuracy of structural determinations.

Earlier studies have shown that the profile of mutations induced by (+)-7R,8S-dihydroxy-9S,10R-epoxy-7,8,9,10-tetrahydro benzo[a]pyrene [(+)-BPDE] at the hypoxanthine (guanine) phosphoribosyltransferase (hprt) gene of Chinese hamster V79 cells was dependent on the concentration of (+)-BPDE. In the present study, we examined the effect of the concentration of (+)-BPDE on its mutational profile at the hprt gene in repair-deficient V-H1 cells (a derivative of V79 cells) to explore the role of DNA repair in the dose-dependent mutational profile of (+)-BPDE. Independent hprt mutant clones were isolated after exposing V-H1 cells to dimethylsulfoxide (DMSO) or to low (4-6 nM; 95% cell survival) or high (40-48 nM; 31% cell survival) concentrations of (+)-BPDE in DMSO. The mutation frequencies for the DMSO control and for the low and high concentration groups were 0.1, 2.1 and 32.9 mutant colonies/10⁵ survivors, respectively. The profile of mutations at the hprt gene was characterized for 148 (+)-BPDE-induced mutant clones and the results from the present study were compared with those obtained earlier with V79 cells. The data indicated that: (i) V-H1 cells were ~9-fold more sensitive to the cytotoxic effects of (+)-BPDE than V79 cells; (ii) the mutation frequency in V-H1 cells was similar to that observed in V79 cells following exposure to similar concentrations of (+)-BPDE; (iii) (+)-BPDE-induced mutations at guanine on the transcribed strand of the hprt gene were common in V-H1 cells but were extraordinarily rare in V79 cells; (iv) (+)-BPDE-induced mutations at adenine on the transcribed strand of the hprt gene were common in both V-H1 and V79 cells; (v) although exposure of V79 cells to different doses of (+)-BPDE resulted in a dose-dependent mutational profile at the hprt gene, this was not observed in V-H1 cells. Our observations indicate a defect in the transcription-coupled repair of (+)-BPDE-DNA adducts in V-H1 cells and that the repair activity deficient in V-H1 cells is essential for the dose-dependent mutational profile observed with (+)-BPDE in V79 cells.

Earlier studies have shown that the profile of mutations induced by (+)-7R,8S-dihydroxy-9S,10R-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (+)-BPDE at the hypoxanthine (guanine) phosphoribosyltransferase (hprt) gene of Chinese hamster V79 cells was dependent on the concentration of (+)-BPDE. In the present study, we examined the effect of the concentration of (+)-BPDE on its mutational profile at the hprt gene in repair-deficient V-H1 cells (a derivative of V79 cells) to explore the role of DNA repair in the dose-dependent mutational profile of (+)-BPDE. Independent hprt mutant clones were isolated after exposing V-H1 cells to dimethylsulfoxide (DMSO) or to low (4-6 nM; 95% cell survival) or high (40-48 nM; 31% cell survival) concentrations of (+)-BPDE in DMSO. The mutation frequencies for the DMSO control and for the low and high concentration groups were 0.1, 2.1 and 32.9 mutant colonies/10(5) survivors, respectively. The profile of mutations at the hprt gene was characterized for 148 (+)-BPDE-induced mutant clones and the results from the present study were compared with those obtained earlier with V79 cells. The data indicated that: (i) V-H1 cells were approximately 9-fold more sensitive to the cytotoxic effects of (+)-BPDE than V79 cells; (ii) the mutation frequency in V-H1 cells was similar to that observed in V79 cells following exposure to similar concentrations of (+)-BPDE; (iii) (+)-BPDE-induced mutations at guanine on the transcribed strand of the hprt gene were common in V-H1 cells but were extraordinarily rare in V79 cells; (iv) (+)-BPDE-induced mutations at adenine on the transcribed strand of the hprt gene were common in both V-H1 and V79 cells; (v) although exposure of V79 cells to different doses of (+)-BPDE resulted in a dose-dependent mutational profile at the hprt gene, this was not observed in V-H1 cells. Our observations indicate a defect in the transcription-coupled repair of (+)-BPDE-DNA adducts in V-H1 cells and that the repair activity deficient in V-H1 cells is essential for the dose-dependent mutational profile observed with (+)-BPDE in V79 cells.

The noble gas krypton is shown to bind to crystallized proteins in a similar way to xenon [Schiltz, Prangé & Fourme (1994). J. Appl. Cryst.27, 950–960]. Preliminary tests show that the major krypton binding sites are essentially identical to those of xenon. Noticeable substitution is achieved only at substantially higher pressures (above 50 × 105Pa). As is the case for xenon, the protein complexes with krypton are highly isomorphous with the native structure so that these complexes can be used for phase determination in protein crystallography. Krypton is not as heavy as xenon, but its K‐absorption edge is situated at a wavelength (0.86 Å) that is readily accessible on synchrotron radiation sources. As a test case, X‐ray diffraction data at the high‐energy side of the Kedge were collected on a crystal of porcine pancreatic elastase (molecular weight of 25.9 kDa) put under a krypton gas pressure of 56 × 105Pa. The occupancy of the single Kr atom is approximately 0.5, giving isomorphous and anomalous scattering strengths of 15.2 and 1.9 e, respectively. This derivative could be used successfully for phase determination with the SIRASmethod (single isomorphous replacement with anomalous scattering). After phase improvement by solvent flattening, the resulting electron‐density map is of exceptionally high quality, and has a correlation coefficient of 0.85 with a map calculated from the refined native structure. Careful data collection and processing, as well as the correct statistical treatment of isomorphous and anomalous signals have proven to be crucial in the determination of this electron‐density map. Heavy‐atom refinement and phasing were carried out with the program SHARP, which is a fully fledged implementation of the maximum‐likelihood theory for heavy‐atom refinement [Bricogne (1991). Crystallographic Computing5, edited by D. Moras, A. D. Podjarny & J. C. Thierry, pp. 257–297. Oxford: Clarendon Press]. It is concluded that the use of xenon and krypton derivatives, when they can be obtained, associated with statistical heavy‐atom refinement will allow one to overcome the two major limitations of the isomorphous replacement method i.e.non‐isomorphism and the problem of optimal estimation of heavy‐atom parameters.

A protein crystallography experiment at the xenon K‐edge (λ= 0.358 Å) has been successfully carried out at the materials science beamline (BL2/ID11) of the ESRF. The samples used in this methodological study were crystals of porcine pancreatic elastase, a 26 kDa protein of known structure. The diffraction data are of excellent quality. The combination of isomorphous replacement and anomalous dispersion of a single xenon heavy‐atom derivative allowed accurate phase determination and the computation of a high‐quality electron density map of the protein molecule. This is the first fully documented report on a complete protein crystallography experiment, from data collection up to phase determination and calculation of an electron density map, carried out with data obtained at ultra‐short wavelengths. Experimental considerations as well as possible advantages and drawbacks of protein crystallography at very short and ultra‐short wavelengths are discussed.