Direct functionalization of an optical fiber by a plasmonic nanosensor.

We explore a rapid route for fabricating silver nanoparticles (NPs) at the end of an optical fiber. The size and number of silver NPs can be controlled by varying the exposure doses. The effect of the refractive index of different solvents on the extinction spectra have been studied as a proof of concept of a fiber integrated plasmon-based sensor.

Is external rotation the correct immobilisation for acute shoulder dislocation? An MRI study.

INTRODUCTION: Anterior dislocation of the shoulder is frequent, with high rates of recurrence. Immobilization in external rotation (ER) seems to improve results, although few studies have actually demonstrated this. The present MRI study examined the impact of ER on labral and capsular ligamentous complex lesions after primary dislocation. MATERIAL: A prospective study was started up on January 1st, 2007. Inclusion criteria were: acute initial anteromedial dislocation of the shoulder, without past history of shoulder trauma. There were 23 such patients, with a mean age of 37 years. METHODS: Early MRI scan used the following protocol: one acquisition in internal rotation followed by one in ER. Study criteria were: hemarthrosis, ER amplitude, rotator cuff status, bone lesion, and labral lesion stage (Habermeyer's classification) and displacement (Itoi criteria). RESULTS: There were 12 right and 11 left shoulders. Mean time to MRI was 3.7 days. There were three rotator cuff tears, no glenal lesions, and 14 humeral notches. Hemarthrosis was almost systematically present, with its distribution modified by ER in 75% of cases; three patients showed no posterior hemarthrosis, in whatever rotation. Mean ER was 37 degrees. On Habermeyer's classification, there were 12 stage-1 lesions, and 10 stage-2; one patient had no labral lesion. All separated labra were reduced in ER, five (21%) totally. In six cases, labral displacement changed according to rotation. All anterior joint effusion was reduced in ER, in three cases totally. DISCUSSION: According to Itoi among others, immobilization in ER is the way to reduce recurrence of anterior dislocation. The present study confirmed that labral reduction was systematic with ER, but it was by no means always complete. ER seemed more effective in reducing the separation. Results further confirmed that ER reduced anterior capsule volume, a recurrence factor. CONCLUSION: ER reduced hemarthrosis, anterior capsule detachment and labral lesions, and never the contrary. The interest of immobilization in ER to prevent shoulder instability needs confirming by long-term clinical studies; we are therefore extending the present MRI study by a clinical study of ER immobilization in all patients showing significant labral lesion reduction. LEVEL OF EVIDENCE: Level IV. Retrospective therapeutic study.

Chronic lateral ankle instability surgical repairs: the long term prospective.

UNLABELLED: The present study sought to assess the clinical and radiological results and long-term joint impact of different techniques of lateral ankle ligament reconstruction. MATERIAL AND METHODS: A multicenter retrospective review was performed on 310 lateral ankle ligament reconstructions, with a mean 13-year-follow-up (minimum FU: 5 years). Male subjects (53%) and sports trauma (78%) predominated. Mean duration of instability was 92 months; mean age at surgery was 28 years. Twenty-eight percent of cases showed subtalar joint involvement. Four classes of surgical technique were distinguished: C1, direct capsular ligamentous complex reattachment; C2, augmented repair; C3, ligamentoplasty using part of the peroneus brevis tendon and C4, ligamentoplasty using the whole peroneus brevis tendon. Clinical and functional assessment used Karlsson and Good-Jones-Livingstone scores; radiologic assessment combined centered AP and lateral views, hindfoot weight-bearing Méary views and dynamic views (manual technique, Telos or self-imposed varus). RESULTS: The majority of results (92%) were satisfactory. The mean Karlsson score of 90 [19-100] (i.e., 87% good and very good results) correlated with the subjective assessment, and did not evolve over time. Postoperative complications (20%), particularly when neurologic, were associated with poorer results. Control X-ray confirmed the very minor progression in degenerative changes, with improved stability; there was, however, no correlation between functional result and residual laxity on X-ray. Unstable and painful ankles showed poorer clinical results and more secondary osteoarthritis. Analysis by class of technique found poorer results in C4-type plasties and poorer control of laxity on X-ray in C1-type tension restoration. DISCUSSION: The present results confirm the interest of lateral ankle ligamentoplasty in the management of instability and protection against secondary osteoarthritis, and of precise lesion assessment (CT-scan/MRI) to adapt surgery to the ligamentary and associated lesions. LEVEL OF EVIDENCE: Level IV. Retrospective therapeutic study.

Effect of dual cure composite as dentin substitute on the marginal integrity of Class II open-sandwich restorations.

This study compared the marginal adaptation of Class II open-sandwich restorations with an RMGIC versus a dual-cure composite as dentin substitute. Class II cavities were prepared on 50 extracted human third molars. The teeth were randomly assigned to two groups of 25 teeth to compare one dual cure composite (Multicore Flow) with one resin-modified glass-ionomer cement (Fuji II LC) in open-sandwich restorations covered with a light cure composite. The teeth were thermomechanically cycled (2000 cycles, 5 degrees C to 55 degrees C; 100,000 cycles, 50 N/cm2). The specimens were then sealed with a 1 mm window around the cervical margin interface. Samples were immersed in a 50% w/v ammoniacal silver nitrate solution for two hours and exposed to a photodeveloping solution for six hours. The specimens were sectioned longitudinally and silver penetration was directly measured using a light microscope. The results were expressed as a score ranging from 0 to 3. The data were analyzed with a non-parametric Kruskall and Wallis test. The degree of leakage significantly increased with Multicore Flow (median = 2) compared to Fuji II LC (median = 1). The resin-modified glassionomer cements remain the best intermediate materials when open-sandwich restorations are indicated. A comparison of the degradation of these materials over time remains a topic to be investigated by future studies.

Effect of dual cure composite as dentin substitute on marginal integrity of class II open-sandwich restorations.

The current study compared the marginal adaptation of Class II open-sandwich restorations with a RMGIC versus a dual-cure composite as dentin substitute. Class II cavities were prepared on 50 extracted human third molars. The teeth were randomly assigned to two groups of 25 teeth to compare one dual cure composite (MultiCore Flow) with one resin-modified glass-ionomer cement (Fuji II LC) in open-sandwich restorations recovered with a light cure composite. The teeth were thermomechanocycled (2000 cycles, 5 degrees C to 55 degrees C; 100,000 cycles, 50 N/cm2). The specimens were then sealed with a 1 mm window around the cervical margin interface. Samples were immersed in a 50% w/v ammoniacal silver nitrate solution for two hours and exposed to a photo-developing solution for six hours. The specimens were sectioned longitudinally and silver penetration was directly measured using a light microscope. The results were expressed as a score from 0 to 3. The data were analyzed with a non-parametric Kruskal and Wallis test. The degree of leakage significantly increased with MultiCore Flow (median 2) compared to Fuji II LC (median 1). Resin-modified glassionomer cements remain the best intermediate material when open-sandwich restorations are indicated. A comparison of the degradation of these materials over time remains a topic to be investigated by future studies.

Patellar chondropathy prevalence at anterior cruciate ligament reconstruction: analysis of 250 cases.

INTRODUCTION: Anterior knee instability caused by anterior cruciate ligament (ACL) deficiency results in meniscal as well as chondral femorotibial and/or femoropatellar damages over a more or less long duration delay. This study's objectives were, in chronically deficient ACL patients, to assess onset delay for developing chondral patella lesions and also analyse these lesions characteristics in relation to laxity duration. HYPOTHESIS: Chondral patellar lesions in ACL deficient knees get worse with time. MATERIAL AND METHODS: We reviewed 250 charts of patients who had undergone arthroscopically assisted surgery for knee anterior laxity. The arthroscopic procedures were conducted between January 1995 and January 2005. Chondral damages were evaluated at surgery according both to International Cartilage Repair Society (ICRS) and Bauer and Jackson classifications. The data were analyzed using the Kruskal-Wallis test and the Fisher exact test. RESULTS: Of the 250 analysed charts, 72 patients (28.8%) were found to present chondral patella lesions. The majority of these lesions were superficial and involved the lateral facet area. We observed a statistically significant ICRS worsening grade in relation to laxity duration. DISCUSSION: Few publications in the literature report patellar involvement in anterior laxity of the knee. However, our results are comparable to those of the rare series found. The pathomechanics of these lesions has not yet been precisely identified and requires further biomechanical studies. CONCLUSION: Patellar damage is frequent with anterior laxity (28.8% in our series) and duration is correlated with statistically significant aggravation of these lesions. Currently, the assessment of these patellar lesions is considered less important than meniscal and femorotibial lesions, even though the natural history of ACL disruption seems to be evolving toward degeneration of all the compartments of the knee, including the femoropatellar compartment.

Comparative study of lipolysis by PLA2 of DOPC substrates organized as monolayers, bilayer vesicles and nanocapsules.

The water-soluble lipolytic enzymes act at the interface of insoluble lipid substrates, where the catalytical step is coupled with various interfacial phenomena as enzyme penetration, solubilization of reaction products, loss of mechanical stability of organized assemblies of phospholipids molecule, etc. One biologically relevant example is the enzymatic hydrolysis of DOPC by PLA(2), which results in cleavage of phospholipids molecules into water insoluble lipolytic products, namely oleic acid and lysophospholipid. In general, the enzymatic activity depends on the substrate organization and molecular environment of the catalytic reaction. The lipolysis by phospholipase A(2) of dioleoylphosphatidylcholine substrates organized as monolayer, bilayers vesicles and lipid nanocapsules was studied by measuring the decrease of the surface area at constant surface pressure or increase of the surface pressure at constant area at air-water interface. A kinetic model describing the coupling of the catalytic act with corresponding interfacial phenomena was developed. By using the kinetic model the values for the global hydrolytic kinetic constants were obtained. The obtained value for the monolayer is five orders of magnitude higher than this obtained with small unilamellar vesicles and six orders of magnitude higher then those obtained with lipid nanocapsules. The comparison shows that the enzymatic catalytic act occurring in the lipid environment of the monolayer is more efficacious than at the vesicle and nanocapsules interfaces.

[Comminuted intra-articular fractures of the distal humerus in elderly patients]. / Fractures articulaires complexes de l'extrémité distale de l'humérus chez le sujet âgé

Treatment of comminuted intra-articular fractures of the distal humerus in elderly patients remains a challenge in trauma surgery. These fractures are rare, but their frequency increases. Our multicenter studies collected 238 cases of comminuted intra-articular fractures of the distal humerus in patients older than 65: two hundred and five cases for the retrospective study, 33 for the prospective study with a minimum follow-up of six months. The following criterias were studied: age, sex, state of health (with ASA score), functional scores (with Katz score), osteoporosis by the OST score and dual X-ray absorptiometry. The results were evaluated according to the Mayo Elbow Performance Score (Morrey) and the Quick DASH. X-ray studies were performed in order to assess both results for prosthesis and osteosynthesis. The following criteria were studied: bone healing, quality of reduction, signs of arthritis (Broberg-Morrey), prosthetic position, mechanical complications, prosthesis fixation. There were 80% of women in good health according to the ASA score (more than 70% of ASA 1 or 2). Most of them (80%) were self-governing and living at home. Hundred and seventy-two patients had an osteosynthesis and 44 had a prosthetic reconstruction (like Coonrad-Morrey prosthesis). Patients treated with osteosynthesis were younger (mean age was 77) than those treated with prosthetic reconstruction (mean age 81). Mean follow-up was 32 months. Results of osteosynthesis were good and excellent for 77% of the patients. Complications occurred for 20% of patients with a reoperation rate of 13%. Results of prosthetic reconstruction were good and excellent for 83% of the patients with 14% of complications and 6% of reoperation. Prosthetic reconstruction seemed to be better than osteosynthesis according to the Mayo Clinic score (84 points versus 77 points for the retrospective study and 95 points versus 75 points for the prospective study). However, the statistical analysis was not significant. Treatment of these fractures must be discussed according to the physiological status of the patient and the fracture patterns (scan evaluation). In conclusion, osteosynthesis remains the standard treatment when stable fixation is feasible. However, prosthetic reconstruction should be discussed for dependant patients or with comorbidity factors, bad bone quality leading to poor osteosynthesis or complex fracture.

Action of Humicola lanuginosa lipase on mixed monomolecular films of tricaprylin and polyethylene glycol stearate.

The hydrolysis catalyzed by Humicola lanuginosa lipase (HLL) of pure tricaprylin (TC) or stearate of polyethylene glycol 1500 (PEG-St) as well as their mixtures spread as monomolecular films were studied. The catalytic transformation of the two substrates TC or PEG-St into their respective reaction products was detected by measuring simultaneously the decrease in the film area and the surface potential using the "zero order" trough at constant surface pressure. A kinetic model describing the enzymatic hydrolysis was developed. The surface concentrations of the two substrates and their respective reaction products as well as the values of the global kinetic constants of hydrolysis were determined. The experimentally obtained global kinetic constants of the catalytic action of HLL against TC and PEG-St present in mixed monolayers of TC/PEG-St are approximately the same as in the case of pure monolayers. These obtained results give some indications that the activity of enzyme is not significantly affected by the different molecular environments in the mixed monolayers.

Secondary exposure for 73 and 200 MeV proton therapy.

Following modifications on the beam line at the Orsay Protontherapy Center, dose measurements were performed in order to make a dose map in the treatment rooms and in the delimited radiation-controlled area around beam line. Measurements were performed using tissue-equivalent proportional counters and rem-counters. Analysis of TEPC single event measurements showed that high LET components (>10 keV.microm(-1)) represent 90 to 99% of total dose equivalent in the treatment rooms and 50 to 90% in the controlled area and quality factors range, respectively between 2 and 15. A fast neutron component was identified in the treatment rooms, where dose equivalent rate varied between few microSv.h(-1) to some dozen of mSv.h(-1). In high-energy radiation field rem-counters underestimated TEPC values for neutron component. The variation between instruments response according to the location is linked to energetic spectrum variations and instrument characteristics.

[Intra-articular fracture of the distal humerus: outcome after osteosynthesis in patients over 60]. / Résultats de l'ostéosynthèse des fractures articulaires de la palette humérale chez le sujet âgé

PURPOSE OF THE STUDY: This is a retrospective analysis of patients aged over 60 years treated in a single center for intra-articular fractures of the distal humerus. Outcomes were compared with published results for osteosynthesis and arthroplasty. MATERIAL AND METHODS: The cohort included 34 patients (36 fractures) reviewed at mean 35 months. Mean age was 77.6 years. Fracture types were: C1: 8, C2: 10, C3: 18. The transtricipital posteromedial approach was used in the majority of patients. Fixation was achieved with a prebent lateral plate (n=11 fractures), a Y-plate (n=9), two plates (n=4), pins or screws (n=9) and an external fixator (n=3). Outcome was assessed with the Mayo elbow score, the Bröberg radiographic score and patient satisfaction. The social impact was also noted. RESULTS: The mean Mayo elbow score was 73.3; outcome was excellent (n=13), good (n=8), fair (n=5) and poor (n=10). Pain persisted in 23 patients. The mean range of movement was 80 degrees . Patient satisfaction remained good. Ten patients did not recover their preoperative level of autonomy. Radiological signs of osteoarthritis were noted for 75% of patients and nonunion of the humeral fracture in 32%. There were three superficial infections and four neurological lesions. DISCUSSION: Good and very good outcome was noted for 59% of the osteosyntheses in this series, compared with 71% in the literature. The rate for arthroplasty is 95%. The mean range of motion is 101 degrees , 17% of patients with a prosthesis complain of pain, 5% develop a superficial infection and 6.5% suffer neurological injury. The estimated rate of revision for arthroplasty is 11% at 7 years. CONCLUSION: Beyond the age of 65 years and based on evidence reported in the literature, it would be advisable to prefer another mode of treatment for these intra-articular fractures, for example elbow arthroplasty, particularly for comminutive fractures on osteoporotic bone.

Reorganization of lipid nanocapsules at air-water interface: Part 2. Properties of the formed surface film.

The state, electrical and dilatational rheological properties of surface films formed at air-water interface from lipid nanocapsules (LNC) with various compositions as well as model monolayers formed by the LNC constituents-Labrafac, Solutol and Lipoid are investigated. These nanocapsules constitute potential drug delivery systems where lypophilic drug will be loaded in their core. The study of the model Labrafac/Solutol (Lab/Sol) mixed monolayers shows behavior close to the ideal. Small negative deviations in the mean molecular areas a and dipole moments mu are observed. All studied monolayers have elastic behavior during the small continuous compressions. The comparison between the properties of surface films formed from LNC with those of the model monolayers confirms the idea developed in the kinetic study that the surface films formed after a rapid disaggregation of the unstable nanocapsule fraction (LNC I) contains mainly Labrafac and Solutol. The Labrafac molar part (xLab) in the formed Lab/Sol mixed layer is established.

Reorganization of lipid nanocapsules at air-water interface. I. Kinetics of surface film formation.

The size, the electrical properties and the behaviour at air-water interface of lipid nanocapsules (LNC) with various compositions were investigated. Two populations of LNC are presented in the suspension after the preparation: with (LNC II) and without (LNC I) phospholipid molecules. After the spreading at air-water interface, a rapid disaggregation of LNC I, located in the vicinity of interface, occurs leading to formation of surface film. The phospholipid molecules stabilize the structure of nanocapsules and LNC II are more stable at the interface in comparison with LNC I. The formation of a surface film was followed after by measuring the evolution of the surface pressure, relative surface area change and surface potential. A kinetic approach describing the various processes during the surface film formation was proposed. The corresponding kinetic constants were estimated.

Reorganization of lipid nanocapsules at air-water interface 3. Action of hydrolytic enzymes HLL and pancreatic PLA2.

The action of the hydrolytic enzymes humicola lanuginosa lipase (HLL) and pancreatic phospholipase A2 (PLA2) on monolayers formed from lipid nanocapsules (LNC) and model monolayers containing their components, Labrafac, Solutol and Lipoid, is studied by simultaneous measuring the changes in the film area and the surface potential in the "zero order" trough at constant surface pressure (pi). The kinetic models describing the hydrolysis by HLL of the Labrafac, Solutol and their mixtures have been proposed. By using the developed theoretical approach together with the experimental results the surface concentrations of the substrates, hydrolysis products and values of the global kinetic constants were obtained. The comparison between the global kinetic constants in the case of HLL hydrolysis of pure Labrafac, Solutol monolayers and those of the model mixed Labrafac/Solutol monolayers, shows that the rates of hydrolysis are of the same order of magnitude, i.e. an additively of the HLL enzyme action is observed. The composition of the mixed Labrafac/Solutol monolayer, formed after the interfacial LNC destabilization, was estimated.

Interactions between hen egg-white lysozyme, PEG2,000, and PLA50 at the air-water interface.

In this paper, we compared the efficiency of polymer films, made of a poly(ethylene glycol) (PEG2,000)/poly(d,l-lactide) (PLA50) mixture, or a PEG2,000-PLA50 copolymer, to prevent adsorption of a model protein, the hen egg-white lysozyme (HEWL), at the air-water interface. This was achieved by analyzing the surface pressure/surface area curves, and the X-ray reflectivity data of the polymer films spread on a Langmuir trough, obtained in absence or in presence of the protein. For both the mixture and the copolymer, the amount of protein adsorbed at the air-water interface decreases when the density of the polymer surface coverage increases. It was shown that even in a condensed state, the polymer film made by the mixture can not totally prevent HEWL molecules to adsorb and penetrate the polymer mixed film, but however, protein molecules would not be directly exposed to the more hydrophobic phase, i.e. the air phase. It was also shown that the configuration adopted by the copolymer at the interface in its condensed state would prevent adsorption of HEWL molecules for several hours; this would be due in particular to the presence of PEG segments in the interfacial film.

[Perforation of the sigmoid colon secondary to acetabular fracture]. / Perforation sigmoïdienne consécutive à une fracture de l'acétabulum.

Traumatic lesions of the colon associated with fracture of the acetabulum occurs in less than 2% of the cases. Direct perforation of the colon by a bony spike, which occurred in our patient, is even more exceptional. We were unable to find any other case reported in the literature. This case illustrates the importance of looking for intestinal lesions in all patients with pelvic injury presenting an unexplained infectious syndrome. Imaging provides clear evidence for avoiding late diagnosis and life-threatening situations.

[Extra-spinal cause of recurrent sciatalgia after disk surgery: a case report]. / Récidive sciatalgique de cause extra-rachidienne après chirurgie discale. A propos d'un cas.

There is a general consensus concerning the clinical and radiological approach to diagnosis and proper management strategy in patients with sciatalgia subsequent to disk herniation. Recurrent herniation is the most probable diagnosis when pain recurs the same territory long after surgery. Despite advances in computed tomographic and magnetic resonance imaging, it may be difficult to identify the real source of the pain in some patients. We report a patient with renal cell cancer who developed recurrent sciatic pain which did not respond to disk surgery. This case illustrates the need for an extensive work-up before implicating the spine as the cause of recurrent sciatalgia.

Spectroscopic studies on poly(ethylene glycol)-lysozyme interactions.

In the present paper, different spectroscopic methods were applied to evaluate conformational changes of hen egg-white lysozyme (HEWL) in various solvents and in the presence of poly(ethylene glycol) (PEG). In citrate (0.007M, pH=6), or in Tris (0.1M, pH=7.4), no conformational change of the protein was measured across the range of concentrations tested. In addition, HEWL in ultra-pure water revealed no irreversible conformational change and no activity loss, at least at low concentrations (< or =0.2mg/ml). Whereas PEG can induce a reorganization of water molecules, no change of the secondary and tertiary protein conformations was observed in the presence of PEG. In addition, in the presence of PEG of various molecular weights, no change of enzymatic activity of the HEWL was observed across the range of concentrations tested.

Interfacial properties of adsorbed films made of a PEG2000 and PLA50 mixture or a copolymer at the dichloromethane-water interface.

Adsorption kinetics of films of poly(ethylene glycol) (PEG2000) studied by the dynamic pendant drop method showed that PEG2000 was more tensioactive at the dichloromethane (DCM)-water interface than at the air-water interface. When initially solubilized into DCM, PEG2000 segments would form an adsorbed layer with hydrophobic segments buried into the polymer chains turned toward the organic phase. Compression of this layer, accompanied by viscoelastic effects, led to expulsion of some hydrophilic tails toward the water phase. When initially dissolved in water, adsorption of PEG2000 segments led to an elastic PEG2000 layer organized on both sides of the interface. Results showed that when the PEG2000-PLA50 (poly(D,L-lactide)) copolymer film was adsorbed at the DCM-water interface, it resulted in a mixed layer exclusively turned toward DCM and its rheological properties were governed by PLA50. When adsorption at the DCM-water interface resulted from a physical mixture of PEG2000 and PLA50, rheological properties of the film were influenced by the initial localization of PEG2000 in the bulk phases. In the case of a mixed film formed by the adsorption of PLA50 from DCM and PEG2000 from water, results showed that PEG2000 segments totally pushed those of PLA50 away from the interface and exclusively influenced the behavior of the mixed film.