Kinetic analysis of the nucleic acid chaperone activity of the Hepatitis C virus core protein

The multifunctional HCV core protein consists of a hydrophilic RNA interacting D1 domain and a hydrophobic D2 domain interacting with membranes and lipid droplets. The core D1 domain was found to possess nucleic acid annealing and strand transfer properties. To further understand these chaperone properties, we investigated how the D1 domain and two peptides encompassing the D1 basic clusters chaperoned the annealing of complementary canonical nucleic acids that correspond to the DNA sequences of the HIV-1 transactivation response element TAR and its complementary cTAR. The core peptides were found to augment cTAR-dTAR annealing kinetics by at least three orders of magnitude. The annealing rate was not affected by modifications of the dTAR loop but was strongly reduced by stabilization of the cTAR stem ends, suggesting that the core-directed annealing reaction is initiated through the terminal bases of cTAR and dTAR. Two kinetic pathways were identified with a fast pre-equilibrium intermediate that then slowly converts into the final extended duplex. The fast and slow pathways differed by the number of base pairs, which should be melted to nucleate the intermediates. The three peptides operate similarly, confirming that the core chaperone properties are mostly supported by its basic clusters

ETUDE COMPARATIVE DE LA RECONSTRUCTION DU LIGAMENT CROISE ANTERIEUR ISOLEE OU ASSOCIEE A UNE PLASTIE EXTRA-ARTICULAIRE EXTERNE (A PROPOS D'UNE SERIE RANDOMISEE DE 63 PATIENTS ; TRAVAIL DU SERVICE DE CHIRURGIE ORTHOPEDIQUE ET TRAUMATOLOGIQUE ET DE MEDECINE DU SPORT DU CENTRE HOSPITALIER LYON-SUD PR B. MOYEN - PR J.L. LERAT)

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

RESULTATS DE 115 CHANGEMENTS DE COTYLES DE PROTHESES DE HANCHE DESCELLES, PAR DES CUPULES A PLOTS REVETUES D'HYDROXYAPATITE, AVEC RECONSTRUCTION OSSEUSE PAR AUTOGREFFE PRINCIPALEMENT ET ALLOGREFFE ; ETUDE DE LA MIGRATION DES IMPLANTS, ASSISTEE PAR ORDINATEUR, SUR RADIOGRAPHIES NUMERISEES ; TRAVAIL DU SERVICE DE CHIRURGIE ORTHOPEDIQUE ET TRAUMATOLOGIQUE DU CENTRE HOSPITALIER LYON-SUD, PR B. MOYEN - PR J.L. LERAT

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Résultats à plus de 15 ans de la reconstruction du ligament croisé antérieur par un procédé associant une plastie intra-articulaire au tendon rotulien à une plastie extra-articulaire externe au tendon quadricipital appelé procédé de "Mac Injones"

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Anterior cruciate ligament revision: analysis and results from a series of 74 cases

Résumé Cette étude rétrospective d'une série continue de 100 patients opérés pour une reprise de ligamentoplastie du ligament croisé antérieur (LCA) entre 1996 et 2004 avait pour but d'apprécier le résultat fonctionnel et de déterminer d'éventuels facteurs pronostiques. La série comportait 74 ligamentoplasties du LCA avec un recul supérieur à 1 an. L'évaluation fonctionnelle a utilisé le score IKDC. La laxité a été mesurée par l'arthromètre KT-1000 et par des radiographies dynamiques. La reconstruction ligamentaire a été réalisée 78 mois en moyenne après l'intervention initiale et dans 93 % des cas sous arthroscopie. Une autogreffe a été utilisée dans tous les cas, avec 57 % de tendons rotuliens, 20 % de tendons quadricipitaux, 18 % de tendons ischio-jambiers, 4 % de tendons rotuliens associés à un tendon quadricipital et 1 % de fascia lata. Le recul moyen est de 21,2 mois. Le score IKDC subjectif moyen était de 71,7 sur 100 et 78 % des genoux étaient considérés comme normaux ou presque normaux à l'examen. Les mesures arthrométriques ont montré un gain moyen en laxité différentielle de 5 mm ± 3 pour le test maxi-manuel. Les radiographies dynamiques ont montré un gain moyen en laxité différentielle de 3 mm ± 4 sur le compartiment médial et de 2 mm ± 4,5 sur le compartiment latéral. L'existence de lésions méniscales (24 cas) a favorisé la dégradation arthrosique et l'existence de lésions cartilagineuses (33 cas) ont altéré le résultat fonctionnel. Les reprises de ligamentoplastie du LCA n'ont pas donné un résultat fonctionnel aussi bon que lors d'une plastie de première intention. L'utilisation initiale d'un ligament synthétique, l'existence de lésions méniscales et cartilagineuses ont été un facteur péjoratif. Purpose of the study This was a retrospective series of patients who underwent revision ligamentoplasty of the anterior cruciate ligament (ACL). We wanted to assess the functional outcome after this type of surgery and search for potential prognostic factors. Material and methods The series included 74 patients, mean age 34 years (range 21-59 years). The initial ligamentoplasty was performed with a synthetic ligament (n = 16), an autograft (n = 57) or an allograft (n = 1). Differential laxity (KT-1000 maximal manual) was 7 ± 2.5 mm. Anterior drawer was measured on the stress x-rays in 20° flexion: medial 8 ± 4.7 mm, lateral 8.3 ± 4.9 mm. Mean time to revision surgery was 78 months. Reconstruction was performed arthroscopically in 69 knees. The implant used for the revision reconstruction was an autograft: patellar tendon (n = 42), quadriceps tendon (n = 15), hamstring tendon (n = 13), patellar tendon and quadriceps tendon (MacInJones) (n = 3), fascia lata (n = 1). A meniscal tear was noted in 24 knees and a cartilage lesion in 35. Results Outcome was assessed at mean 21.2 months follow-up. The mean IKDC function score was 71.7 (range 21.8-100). 78% of patients considered their knee normal or nearly normal and 88% presented a positive Lachmann. Mean differential laxity measured with KT-1000 (maximal manual) was 2 ± 1.7 mm. Stress x-rays revealed a mean differential laxity measured at 3.7 ± 2.3 mm medially and 6.3 ± 4.3 mm laterally. The presence of a meniscal lesion favored osteoarthritic degradation. Presence of chondral lesions altered the functional outcome significantly and limited resumption of sports activities. An initial repair using a synthetic ligament affected the functional outcome after revision surgery and favored or aggravated chondral lesions. Discussion The clinical results we have obtained with revision ACL ligamentoplasty are comparable to pervious series reported in the literature. The functional outcome is not as good as after first-intention repair, especially if the initial plasty was done with a synthetic ligament and the knee presented meniscal or cartilage damage

PROTHESES DU GENOU APRES ECHECS DES OSTEOTOMIES POUR GONARTHROSE (A PROPOS DE 69 PROTHESES A GLISSEMENT CONSERVANT LES DEUX LIGAMENTS CROISES OU LE LIGAMENT CROISE POSTERIEUR SEUL)

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Calcaneal intra-articular fracture osteosynthesis: Clinical and radiological prospective study of 31 cases

Osteosynthesis for calcaneal fractures remains controversial. We osteosynthesize all displaced intraarticular fractures, the only contraindications regarding age, local and arterial status, or non-compliance. We here report a prospective study of 31 calcaneal articular fractures, with a mean 4.5 years follow-up. Following CT scan, patients were operated at a mean 6.1 days with the same surgical (single surgeon-extended lateral approach) and post-operative protocol. On Sanders' classification, there were 18 type II, 8 type III, and 5 type IV fractures. Twenty-six patients had clinical and comparative standard X-ray follow-up; 19 also had CT assessment. Two complications needed repeat surgery: one limited skin necrosis, one infected hematoma. Fifty-eight % were very satisfied, and 42% satisfied; 77% returned to work. Mean Kitaoka score was 86.2. Tibiotarsal motion was normal, and subtalar motion 45%. X-ray confirmed anatomical reconstruction: no joint reduction defect; medial arch angle, calcaneal pitch, calcaneal soft-pad thickness, and calcaneus height, length and width subnormal. Mean Boehler angles were: 6.6° preoperatively, 32.3° postoperatively, and 27.1° on follow-up for injured vs. 32° for non-injured foot. Thirty-six % had posterior subtalar remodeling on standard X-ray, and 79% on CT scan, without correlation with functional results or radiological type. Due to calcaneal posterior facet height loss, we recommend 10 weeks' non-weightbearing. These good results match the literature, generally indicating surgery for displaced calcaneal intraarticular fractures

Effect of vitamin C on prevention of complex regional pain syndrome type I in foot and ankle surgery

BACKGROUND: The public health cost impact of complex regional pain syndrome type I (CRPS I) is considerable in both emergency and scheduled orthopaedic surgery. We proposed to assess the effectiveness of vitamin C in prevention of CRPS I in foot and ankle surgery. METHODS: We carried out a "before-after" quasi-experimental study comparing two chronologically successive groups without (Group I: July 2002-June 2003) and with (Group II: July 2003-June 2004) preventive 1g daily vitamin C treatment. All patients having surgery on the foot or ankle were enrolled, with the exception of diabetic foot cases. Several factors were analysed: sex, age, type of pathology, history of CRPS I, psychological context, tourniquet time, and cast immobilisation time. RESULTS: 420 feet (392 patients) were included in the study: 185 in Group I, 235 in Group II. CRPS I occurred in 18 cases in Group I (9.6%) and 4 cases in Group II (1.7%) (p<10(-4)), with history of CRPS I as a significantly correlated factor (relative risk=10.4). The psychological context (anxio-depressive state) showed a (sub-significant) tendency to increase the risk of CRPS I (relative risk=2.6). CONCLUSION: Vitamin C has been shown to be effective in preventing CRPS I secondary to wrist fracture, but few data are available with respect to foot and ankle cases. The present study demonstrates the effectiveness of vitamin C in preventing CRPS I of the foot and ankle-a frequent complication in our control group (9.6%). The authors recommend preventive management by vitamin C

Reconstruction simultanée des 2 ligaments croisés par un transplant autogène unique: Technique et résultats à propos de 25 laxités chroniques

Résumé Les cas de rupture ancienne des 2 ligaments croisés sont rares et leur prise en charge n'est pas codifiée. Leur reconstruction dans le même temps chirurgical est, dans la littérature, une option récente datant de 1996, avec seulement 44 cas recensés dans 6 publications où ils étaient mélangés à des cas récents, posant d'autres problèmes. Nous rapportons les résultats de 25 genoux opérés entre 1983 et 2004 avec une technique utilisant un seul transplant provenant du système extenseur et une seule voie d'abord.Un long transplant tendon rotulien-rotule-tendon quadricipital de 30 cm a été utilisé. Vingt-cinq genoux qui présentaient une laxité et une instabilité majeures ont été opérés dont 14 avaient déjà subi une ou 2 opérations. Le tiroir différentiel antérieur était de 10 ± 3 mm en dedans et de 9 ± 5 mm en dehors, le tiroir postérieur à 70? était de 15 ± 4 mm en dedans et de 10 ± 6 mm en dehors. La laxité antéropostérieure totale du compartiment médial était de 29 mm et la laxité du compartiment latéral était de 30 mm. Les résultats fonctionnels, au recul moyen de 6,5 ans (1 à 21), ont été satisfaisants (sauf dans 3 cas) avec reprise de l'activité professionnelle, mais peu d'activité sportive et aucun genou n'a été classé A dans la cotation de l'IKDC, ce qui corrobore les résultats de la littérature. Les résultats anatomiques jugés sur le tiroir radiologique étaient modestes puisque le gain moyen sur le tiroir antérieur était de 4 et 5 mm dans les 2 compartiments médial et latéral et sur le tiroir postérieur, de 5 mm en dedans et de 3 mm en dehors. La laxité périphérique a été mieux corrigée. La reconstruction simultanée avec cette technique a plusieurs avantages : une seule voie d'abord antérieure, un seul transplant avec lequel on fait en plus une plastie latérale, une courte immobilisation avec une rééducation rapide. Purpose of study Chronic tears of both cruciate ligaments are rarely encountered. Management practices have varied. One-stage reconstruction of both ligaments using arthroscopically implanted allografts was proposed starting in 1996 for such chronic laxity but only 44 cases have been reported in six papers mixed in with recent cases raising very different problems. Treatments using allografts or autogenous grafts or both implanted arthroscopically have often been combined with open surgery. We report a retrospective analysis of 25 knees treated with the same technique from 1983 to 2004: reconstruction with a single transplant taken from the extensor system. Material and methods A 30-cm lenght patella tendon-patella-quadriceps tendon graft was harvested. The patellar block was fixed in a hole drilled under the tibial spine, the patellar tendon replacing the posterior cruciate ligament and the quadriceps tendon passing through the lateral condyle and replacing the anterior cruciate ligament before implantation on Gerdy's tubercle, this also creating an extra-articular plasty with the same implant. Medial, lateral and posterior plasties were performed, depending on the radiographic assessment of laxity. Twenty-five knees with major laxity and instability were operated on, including 14 in two-stage operations. The differential anterior drawer was 10±3 mm medially and 9±5 mm laterally. The posterior drawer at 70? was 15±4 mm medially and 10±6 degrees laterally. The total anteroposterior laxity of the medial compartment was 29 mm, it was 30 mm for the lateral compartment. Lateral laxity was considered major (&#62;10?) in 17 knees and medial laxity in 7. Lateral and medial laxities were associated in eleven knees. Hyper-extension was very severe in five knees. Results Functional outcome at mean 6.5 years follow-up (range 1-21) was satisfactory (except in three knees) allowing renewed occupational activity. Resumption of sports activity was less marked and none of the knees was in IKDC class A, corroborating results in the literature. Anatomic outcome was assessed on the radiological drawer decrease which was modest, mean gain in the anterior drawer measuring 4 and 5 mm in the medial and lateral compartments and mean gain in the posterior drawer measuring 5 mm medially and 3 mm laterally. Peripheral laxity was corrected for best. Discussion Classically, one or other of the cruciate ligaments is repaired, sometimes both, but in a two-stage procedure associating two different methods and autogenous tendon grafts. One-stage reconstruction of both cruciate ligaments with a single autogenous graft and a wide approach has not led to any complications. One-stage reconstruction using this technique has several advantages: one anterior incision, single transplant which also enables lateral plasty, short immobilization time with rapid rehabilitation