Biocompatibility of an x-shaped zirconium implant in deep sclerectomy in rabbits

ABSTRACT : Background : The aim of this study was to evaluate the midterm biocompatibility of a new x-shaped implant made of zirconium in an animal model of glaucoma surgery. Methods : Preoperatively, ultrasound biomicroscopy (UBM), intraocular pressure (IOP) and outflow facility (OF) data were acquired. Upon surgery, one eye was chosen randomly to receive an implant, while the other received none. Ten rabbits went through a 1-, 2-, 3-, 4- and 6-month follow-up. [OP was measured regularly, UBM performed at 1, 3 and 6 months after surgery. At the end of the follow-up, OF was again measured. Histology sections were analyzed. Results : For both groups IOP control was satisfactory, while OF initially increased at month 1 to resume preoperative values thereafter. Eyes with implants had larger filtration blebs which decreased faster than in eyes without the implant. Drainage vessel density, inflammatory cell number and fibrosis were higher in tissues near the implant. Conclusions : The zirconium implant initially promoted the positive effects of the surgery (IOP control, OF increase). Nevertheless, after several months, foreign body reactions and fibrosis had occurred on some implants that restrained the early benefit of such a procedure. Modifications of the zirconium implant geometry could enhance the overall success rate.

Orthopedic implant used as drug delivery system: clinical situation and state of the research.

A partial review is proposed on the existing literature for the research performed in orthopedic implant used as drug delivery system. In the first part, an evaluation is given on the clinical need to deliver a drug in the surrounding of an implant. Secondly, a review of the clinical situation is developed for implants already used as drug delivery system. Experimental works performed for local delivery are reported. In particular, a description is given on the in vitro and in vivo studies where the implant is coated with different proteins or drugs. Finally, a conclusion is proposed on the next step in the development of orthopedic implant as drug delivery system mentioning also the industrial situation.

[Illustrations de L'art du fabricant de velours de coton] / Bernard, grav.; Fossier, dess. ; Jean-Marie Roland de la Platière, aut. du texte

Comprend : [Bandeau folio Aij : allégorie de la Justice. Homme écrivant, singe. Ornements à la Bérin.] [Cote : Res Atlas V 117/Microfilm R 101257] ; [Pl.1 : de la mécanique à carder le coton. Vues et développements de la machine à carder le coton.] L'art du fabricant de velours de coton. [Cote : Res Atlas V 117/Microfilm R 101257] ; [Pl.2 : de la mécanique à carder le coton. Machine à carder le coton.] L'art du fabricant de velours de coton. [Cote : Res Atlas V 117/Microfilm R 101257] ; [Pl.3 : de la mécanique à carder le coton. Machine à carder le coton. Fig.4 : petits cadres en fer, implantés sur la charpente de la mécanique, sur lesquels s'appuie et tourne l'axe des cylindres.] L'art du fabricant de velours de coton. [Cote : Res Atlas V 117/Microfilm R 101257] ; [Pl.4 : de la mécanique à filer le coton et de la manière de s'en servir.] L'art du fabricant de velours de coton. [Cote : Res Atlas V 117/Microfilm R 101257] ; [Pl.5 : de la mécanique à filer le coton et de la manière de s'en servir.] L'art du fabricant de velours de coton. [Cote : Res Atlas V 117/Microfilm R 101257] ; [Pl.6 : fabrication du velours. Fig.1 : moulins à retordre les fils de coton, doublés pour la châine des velours] L'art du fabricant de velours de coton. [Cote : Res Atlas V 117/Microfilm R 101257] ; [Pl.7 : fabrication du velours. Fig.1 : vue perspective du métier monté et en travail.] L'art du fabricant de velours de coton. [Cote : Res Atlas V 117/Microfilm R 101257] ; [Pl.8 : fabrication du velours. Armure de piqué pour un carreau quatre points simple ou double, velours velvet-ret, croisé, piqué ou cannelé. Fig.8 : fabrication d'une toile sans lisière.] L'art du fabricant de velours de coton. [Cote : Res Atlas V 117/Microfilm R 101257] ; [Pl.9 : fabrication du velours. Le fourneau à brûler, griller ou raser les velours de coton et de la manière de faire cette opération.] L'art du fabricant de velours de coton. [Cote : Res Atlas V 117/Microfilm R 101257] ; [Pl.10 avec 3 vignettes : vignette 1, fabrication du velours. Des couleurs en bon teint. Atelier de teinture pour les coulers ordinaires, les garançages etc. Vignette 2 : atelier de teinture pour les cuves de bleu. Vignette 3 : atelier de teinture pour les tones de noir.] L'art du fabricant de velours de coton. [Cote : Res Atlas V 117/Microfilm R 101257] ; [Pl.11 : fabrication du velours. Des couleurs en bon teint. De la cuve du bleu à chaud. Mécanique à imprimer au cylindre les toiles, croisés, satinettes, velours de coton etc. Mécanique à découper les velours cannelés et le velvet-ret avec l'ouvrier vu en travail. ] L'art du fabricant de velours de coton. [Cote : Res Atlas V 117/Microfilm R 101257]

In vivo study of an injectable poly(acrylonitrile)-based hydrogel paste as a bulking agent for the treatment of urinary incontinence.

Urinary incontinence can be treated by endoscopic injection of bulking agents, however, no optimal therapeutic effect has been achieved upon this treatment yet. In the present study, the development of a injectable poly(acrylonitrile) hydrogel paste is described, and its efficacy and histological behavior, once injected into the submucosal space of the minipig bladder, are evaluated. A device was developed to mix poly(acrylonitrile) hydrogel powder with glycerin, used as carrier, prior to injection into the submucosal space of the bladder. Several paste deposits, depending on the size of the bladder, were injected per animal. The implants were harvested at days 7, 14, 21, 28, 84 and 168 and analyzed morphologically and by histology. The persistence of the implants was demonstrated. However, at later time points the implants were split up and surrounded by granulomatous tissue, which was gradually replaced by histiocytes and adipocytes. Transitory focal urothelial metaplasia was observed only at day 7 and moderate foreign body reaction was detected predominantly between the second and fifth week. This study demonstrated the feasibility to develop an injectable paste of poly(acrylonitrile) hydrogel thought to provide the expected bulking effect, necessary for the treatment of urinary incontinence.

Is ultracision knife safe and efficient for breast capsulectomy? A preliminary study.

BACKGROUND: Silicone breast implants are used to a wide extent in the field of plastic surgery. However, capsular contracture remains a considerable concern. This study aimed to analyze the effectiveness and applicability of an ultracision knife for capsulectomy breast surgery. METHODS: A prospective, single-center, randomized study was performed in 2009. The inclusion criteria specified female patients 20-80 years of age with capsular contracture (Baker 3-4). Ventral capsulectomy was performed using an ultracision knife on one side and the conventional Metzenbaum-type scissors and surgical knife on the collateral side of the breast. Measurements of the resected capsular ventral fragment, operative time, remaining breast tissue, drainage time, seroma and hematoma formation, visual analog scale pain score, and sensory function of the nipple-areola complex were assessed. In addition, histologic analysis of the resected capsule was performed. RESULTS: Five patients (median age, 59.2 years) were included in this study with a mean follow-up period of 6 months. Three patients had Baker grade 3 capsular contracture, and two patients had Baker grade 4 capsular contracture. The ultracision knife was associated with a significantly lower pain score, shorter operative time, smaller drainage volume, and shorter drainage time and resulted in a larger amount of remaining breast tissue. Histologic analysis of the resected capsule showed no apoptotic cells in the study group or control group. CONCLUSIONS: The results suggest that ventral capsulectomy with Baker grade 3 or 4 contracture using the ultracision knife is feasible, safe, and more efficient than blunt dissection and monopolar cutting diathermy and has a short learning curve. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors at www.springer.com/00266 .

Treatment of velopharyngeal insufficiency by autologous fat injection.

Velopharyngeal insufficiency (VPI) is a structural or functional trouble, which causes hypernasal speech. Velopharyngeal flaps, speech therapy and augmentation pharyngoplasty, using different implants, have all been used to address this trouble. We hereby present our results following rhinopharyngeal autologous fat injection in 18 patients with mild velopharyngeal insufficiency (12 soft palate clefts, 4 functional VPI, 2 myopathy). 28 injections were carried out between 2004 and 2007. The degree of hypernasal speech was evaluated pre- and postoperatively by a speech therapist and an ENT specialist and quantified by an acoustic nasometry (Kay Elemetrics). All patients were exhaustively treated with preoperative speech therapy (average, 8 years). The mean value of the nasalance score was 37% preoperatively and 23% postoperatively (p = 0.015). The hypernasality was reduced postoperatively in all patients (1-3 degrees of the Borel-Maisonny score). There were no major complications, two minor complications (one hematoma, one cervical pain). The autologous fat injection is a simple, safe, minimally invasive procedure. It proves to be efficient in cases of mild velopharyngeal insufficiency or after a suboptimal velopharyngoplasty.

Polymorphisms in fibronectin binding protein A of Staphylococcus aureus are associated with infection of cardiovascular devices.

Medical implants, like cardiovascular devices, improve the quality of life for countless individuals but may become infected with bacteria like Staphylococcus aureus. Such infections take the form of a biofilm, a structured community of bacterial cells adherent to the surface of a solid substrate. Every biofilm begins with an attractive force or bond between bacterium and substratum. We used atomic force microscopy to probe experimentally forces between a fibronectin-coated surface (i.e., proxy for an implanted cardiac device) and fibronectin-binding receptors on the surface of individual living bacteria from each of 80 clinical isolates of S. aureus. These isolates originated from humans with infected cardiac devices (CDI; n = 26), uninfected cardiac devices (n = 20), and the anterior nares of asymptomatic subjects (n = 34). CDI isolates exhibited a distinct binding-force signature and had specific single amino acid polymorphisms in fibronectin-binding protein A corresponding to E652D, H782Q, and K786N. In silico molecular dynamics simulations demonstrate that residues D652, Q782, and N786 in fibronectin-binding protein A form extra hydrogen bonds with fibronectin, complementing the higher binding force and energy measured by atomic force microscopy for the CDI isolates. This study is significant, because it links pathogenic bacteria biofilms from the length scale of bonds acting across a nanometer-scale space to the clinical presentation of disease at the human dimension.

Role of rifampin against Propionibacterium acnes biofilm in vitro and in an experimental foreign-body infection model.

Propionibacterium acnes is an important cause of orthopedic-implant-associated infections, for which the optimal treatment has not yet been determined. We investigated the activity of rifampin, alone and in combination, against planktonic and biofilm P. acnes in vitro and in a foreign-body infection model. The MIC and the minimal bactericidal concentration (MBC) were 0.007 and 4 μg/ml for rifampin, 1 and 4 μg/ml for daptomycin, 1 and 8 μg/ml for vancomycin, 1 and 2 μg/ml for levofloxacin, 0.03 and 16 μg/ml for penicillin G, 0.125 and 512 μg/ml for clindamycin, and 0.25 and 32 μg/ml for ceftriaxone. The P. acnes minimal biofilm eradication concentration (MBEC) was 16 μg/ml for rifampin; 32 μg/ml for penicillin G; 64 μg/ml for daptomycin and ceftriaxone; and ≥128 μg/ml for levofloxacin, vancomycin, and clindamycin. In the animal model, implants were infected by injection of 10⁹ CFU P. acnes in cages. Antimicrobial activity on P. acnes was investigated in the cage fluid (planktonic form) and on explanted cages (biofilm form). The cure rates were 4% for daptomycin, 17% for vancomycin, 0% for levofloxacin, and 36% for rifampin. Rifampin cured 63% of the infected cages in combination with daptomycin, 46% with vancomycin, and 25% with levofloxacin. While all tested antimicrobials showed good activity against planktonic P. acnes, for eradication of biofilms, rifampin was needed. In combination with rifampin, daptomycin showed higher cure rates than with vancomycin in this foreign-body infection model.

Biomechanical concept and clinical outcome of dual mobility cups.

Dual mobility cup systems in total hip arthroplasty consist of a metal back with a non-constrained liner, in which a constrained standard head articulates. While superior stability of such implants in comparison with standard total hip replacements is assumed, it is the purpose of this study to outline the biomechanical concept of dual mobility cups and to describe implant survival and dislocation rate based on the series published in the English-speaking and Francophone literature. A growing body of evidence indicates reduced dislocation rates in primary and revision total hip arthroplasty and in selected tumour cases. The limited availability of studies evaluating long-term implant survival and existing concerns with regard to increased wear rates and aseptic loosening, leads to the conclusion that such implants have to be used with prudence, particularly in standard primary hip arthroplasty and in young patients.

Mechanisms of CYR61 mediated breast cancer metastasis to the lung

CYR61 (Cysteine-rich angiogenic inducer 61) is a matricellular protein that regulates cell proliferation, adhesion, migration and cell survival through interaction with various types of integrin cell adhesion receptors. At tissue level it is implicated in the regulation of embryonic development, wound healing and angiogenesis. CYR61 has also been involved in cancer progression, however its role appears to be diverse and complex depending on the cancer type and stage. Its contribution to metastasis formation is still unclear. Previous findings reported by our laboratory demonstrated that CYR61 cooperates with avßs integrin to promote invasion and metastasis of cancers growing in a pre-irradiated microenvironment. In this work, we used an orthotopic model of breast cancer to show for the first time that silencing of CYR61 in breast cancer cells suppresses lung metastasis formation. Silencing of MDA-MB-231 reduced both local growth and lung metastasis formation of tumor cells implanted in a pre-irradiated mammary fat pad. CYR61 silencing in tumors growing in non-irradiated mammary fat pads did not impact primary tumor growth but decreased lung metastasis formation. The effect of CYR61 on spontaneous lung metastasis formation during natural cancer progression was further examined by using an experimental model of metastasis. Results from these experiments indicate that CYR61 is critically involved in promoting cancer cells entry into lung parenchyma rather than later steps of colonization. In vitro experiments showed that CYR61 promotes tumor cell spreading, migration and transendothelial migration. CYR61 also supported colony formation under anchorage-independent condition and promotes resistance to anoikis through the involvement of ß1 and ß3 integrin. These results indicate that CYR61 promotes lung metastasis of breast cancer by facilitating extravasation into lung parenchyma through enhanced motility, transendothelial migration and resistance to anoikis. - CYR61 (Cysteine-rich angiogenic inducer 61) est une protéine matricellulaire qui régule la prolifération, l'adhérence, la migration et la survie des cellules par son interaction avec différents types de récepteurs d'adhésion cellulaire de la famille des intégrine. Au niveau des tissus, CYR61 est impliquée dans la régulation du développement embryonnaire, de la cicatrisation et de l'angiogenèse. CYR61 a également été impliquée dans le cancer, mais son rôle semble être divers et complexe en fonction du type du cancer et de son stade. Son rôle dans la formation des métastases n'est pas encore clair. Des résultats antérieurs rapportés par notre laboratoire ont montré que CYR61 coopère avec l'intégrine avß5 pour favoriser l'invasion et la métastase de tumeurs se développant dans un micro-environnement pré-irradié. Dans ce travail, nous avons utilisé un modèle orthotopique de cancer du sein pour démontrer pour la première fois que l'extinction (silencing) du gène CYR61 dans le cancer du sein réduit la formation de métastases pulmonaires. L'extinction de CYR61 dans la lignée cellulaire de cancer du sein humain MDA-MB- 231 réduit à la fois la croissance local ainsi que la formation de métastases pulmonaires à partir de cellules implantés dans les coussinets adipeux mammaires pré-irradié. L'extinction de CYR61 dans des tumeurs grandissant dans les coussinets adipeux mammaires non irradiées n'a pas d'incidence sur la croissance tumorale primaire mais réduit la formation des métastases pulmonaires. Par la suite nous avons examiné l'effet de CYR61 sur la formation de métastases pulmonaires en utilisant un modèle expérimental de métastase. Les résultats de ces expériences indiquent que CYR61 est impliquée de manière cruciale dans les étapes précoces de la formation de métastases, plutôt que dans les étapes tardives de colonisation du poumon. Des expériences in vitro ont montré que CYR61 favorise l'étalement, la migration et la transmigration endothéliale des cellules tumorales. CYR61 favorise également la formation de colonies dans des conditions indépendante de l'ancrage et la résistance à l'anoïkis par l'engagement des intégrines ß1 et ß3. Ces résultats indiquent que CYR61 favorise les métastases pulmonaires du cancer du sein en facilitant l'extravasation dans le parenchyme pulmonaire grâce à la stimulation de la motilità, de la migration transmigration endothéliale et de la résistance à l'anoïkis.

Visualization of aqueous shunt position and patency using anterior segment optical coherence tomography.

PURPOSE: To describe the use of anterior segment optical coherence tomography (AS-OCT) to clarify the position and patency of aqueous shunt devices in the anterior chamber of eyes where corneal edema or tube position does not permit a satisfactory view. DESIGN: Noncomparative observational case series. METHODS: Four cases are reported in which aqueous shunt malposition or obstruction was suspected but the shunt could not be seen on clinical examination. The patients underwent AS-OCT to identify the position and patency of the shunt tip. RESULTS: In each case, AS-OCT provided data regarding tube position and/or patency that could not be obtained by slit-lamp examination or by gonioscopy that influenced management. CONCLUSIONS: AS-OCT can be used to visualize anterior chamber tubes in the presence of corneal edema that precludes an adequate view or in cases where the tube is retracted into the cornea. In such cases, AS-OCT is useful in identifying shunt patency and position, which helps guide clinical decision making.

Diagnosis of periprosthetic joint infections.

Advances in implant design, surgical technique, peri-operative antimicrobial prophylaxis and laminar airflow operating room environment have made total joint arthroplasty one of the most successful surgical procedures of all times. Orthopaedic implants, however, remain prone to microbial contamination resulting in persistent risk of implant-associated infection. Treatment of infections associated with orthopaedic devices usually requires appropriate surgical intervention combined with a prolonged antimicrobial therapy. The choice of the best possible treatment regimen depends on duration and pathogenesis of infection, stability of the implant, antimicrobial susceptibility of the pathogen and condition of the surrounding soft tissue. In addition towell known diagnostic procedures new promising tools for rapid and correct microbial diagnosis are being developed as correct diagnosis of the responsible micro-organism and this is paramount for successful treatment of prosthetic joint infection.

Implantes en el paciente irradiado

La colocación de implantes en pacientes previamente irradiados por neoplasias de cabeza y cuello se ha convertido en una práctica creciente. Si el estudio del caso lo permite, es una técnica que puede ser beneficiosa; el criterio y la experiencia del implantólogo deben decidir en cuanto a su aplicación. Por otro lado, en la actualidad más de 200.000 personas son portadoras de implantes dentales y cada año alguno de estos pacientes puede ser sometido a irradiación. Por todo ello, los efectos de la irradiación sobre el implante y los tejidos que lo rodean son motivo de estudio en la actualidad. En este artículo presentamos una revisión bibliográfica sobre los diferentes ensayos diseñados para estudiar el efecto de la irradiación sobre los implantes endoóseos, así como las complicaciones y consideraciones que deben tenerse en cuenta al colocar implantes en pacientes previamente irradiados en la zona de cabeza y cuello.

La cresta alveolar atrófica en implantología oral

Los implantes dentales endoóseos constituyen una alternativa terapéutica ideal en pacienfes parcial o totalmente edéntulos; sin embargo, en ocasiones, la atrofia ósea generalizada o localizada contraindica el tratamiento, siendo necesario realizar un aumento de cresta alveolar que permita, bien simultáneamente o deforma diferida, la adecuada rehabilitación implantológica. En el presente trabajo, hacemos una revisión de las distintas técnicas y materiales utilizados actualmente en implantología, para mejorar las condiciones de recepción de los implantes, en presencia de defectos óseos.

Prótesis sobre implantes en pacientes en crecimiento. A propósito de cuatro casos

El motivo de este trabajo es hacer una revisión actual del nivel de conocimientos respecto a oseointegración y crecimiento. Se presentan cuatro casos de paciente infantil que fueron tratados con técnica implantológica para solucionar problemas derivados de traumatismos que ocasionaron pérdidas dentarias.