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Background: The Dynamic Hip Screw is well established for the treatment of femoral neck fractures. However, cut-out occurs in 1-6% of all cases. This study compared the biomechanical performance of a helical shaped implant (DHS-Blade) to the Dynamic Hip Screw in an unstable femoral neck fracture model., Methods: Ten pairs of human cadaveric femora were either instrumented with a DHS-Blade or a Dynamic Hip Screw. Osteotomies were created using a custom-made saw-guide. Cyclic loading was performed by introducing in vivo measured load-trajectories to the femoral head. Starting at 1500 N, the load was stepwise increased until failure of the construct. Radiographs were taken in 5000 cycles increments to identify onset of femoral head migration with respect to the implant. A survival analysis was performed on the cycles to onset of migration. A paired t-test was carried out on the displacements of the femoral head relative to the shaft as determined by optical motion tracking., Findings: One hundred percent migrations occurred for the Dynamic Hip Screw compared to 50% for the DHS-Blade. The survival probability in terms of implant anchorage was found higher for the blade (P=0.023). However, significant higher deformation of the repair construct was observed for the DHS-Blade (P=0.004)., Interpretation: The study showed superior implant anchorage of the DHS-Blade compared to the DHS, which might reduce the cut-out risk. Nevertheless, the blade allowed higher deformation of the femur mainly resulting in shortening of the neck, which might be due to a systematic loss of fracture reduction.

Calmodulin content and distribution between soluble and particulate fractions were determined by radioimmunoassay in six human melanoma cell lines exhibiting differences in tumor origin (primary or metastatic), degree of tumorigenicity and of pigmentation (amelanotic or melanotic). The results indicate that a) total, soluble and particulate calmodulin levels expressed as ng/10(6) cells or ng/micrograms of proteins remained constant for five out of six cell lines when cells grew from subconfluency to confluency. For IGR 37 line, derived from metastatic melanoma, the calmodulin content decreases from 2.39 to 1.27 ng/micrograms protein for total calmodulin, from 2.17 to 1.52 ng/micrograms protein for soluble calmodulin and from 2.61 to 1.02 ng/micrograms protein for particulate calmodulin, b) total, soluble and particulate calmodulin levels expressed as ng/microgram proteins were twofold (at confluency) to fourfold (at subconfluency) higher in the two cell lines from metastatic origin, IGR 37 and IPC 167. As for example, for total calmodulin, values in IGR 37 and IPC 167 cell lines, were, respectively at subconfluency, 2.39 and 2.31 ng/micrograms protein as compared with the four other cell lines: 0.76 to 0.96 ng/micrograms protein and at confluency: 1.27 and 1.98 ng/micrograms protein as compared with the four other cell lines: 0.76 to 0.90 ng/micrograms protein, c) ratio of calmodulin between soluble and particulate fractions was about 1 for the two autologous cell lines IGR 37 and IGR 39 and varies from 2 to 3 for the four other cell lines.

Autoantibodies (aAb) in serum of patients with autoimmune thyroid diseases (AITD) are directed to an antigen associated with thyroid microsomes. Although it has been investigated over almost three decades, the nature of this autoantigen remained unknown. Taking advantage of monoclonal antibodies (mAb) produced in our laboratory, we have demonstrated that thyroid peroxidase (TPO) is the 'microsomal' antigen. Sera of patients with AITD strongly inhibited the binding of only one of 19 mAb raised against human thyroid plasma membranes. This mAb did not react with thyroglobulin but achieved significant binding to preparations of human, bovine and porcine TPO, bovine lactoperoxidase and human myeloperoxidase without altering the enzyme activity. The mAb has been used to immunopurify the human TPO from solubilized thyroid microsomes. The procedure allowed high purification (approximately 3500-fold) of the native enzyme with a reasonable yield (approximately 10 mg TPO/kg thyroid tissue). Human TPO exhibited a specific activity of 350-400 guaiacol U/mg, a peak in the Soret region and a ratio of A411 nm to A280 nm of 0.20-0.25. Upon SDS-polyacrylamide gel electrophoresis, the purified enzyme gave two contiguous bands in the 100 kDa region. Performed in non-reducing conditions, electrophoresis of TPO showed one band in the same 100 kDa region. Sera with aAb to the microsomal antigen immunoprecipitated purified TPO to an extent ranging from 80 to 100% of the initial enzyme amount while sera from normal subjects or from patients with undectable level of anti-microsomal aAb elicit a decrease of less than 30% of the total TPO activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Radioiodination of the two tyrosine residues (Tyr-99 and Tyr-138) of ox testis calmodulin was performed using several methods, and studied through the specific activity, and the [125I]iodoamino acid analysis of the radiolabeled calmodulins. Hydrolysis by thrombin of 125I-calmodulin labeled by the lactoperoxidase method and subsequent isolation of peptides TM1 and TM2 by gel electrophoresis showed preferential labeling by 125I of Tyr-99 (TM1) over Tyr-138 (TM2). Analysis of [125I]iodoamino acids of radiolabeled TM1, TM2 and calmodulin demonstrated that [125I]monoiodotyrosine was predominant, the remainder being [125I]diiodotyrosine. Radioiodination of wheat germ calmodulin, which contains a single tyrosine residue (Tyr-139), showed that only TM2 was labeled by 125I on the Tyr-139 residue and also on the His-108 residue (radiolabeled monoiodotyrosine, diiodotyrosine and monoiodohistidine being present).

The bactericidal activity of ofloxacin alone and in combination was evaluated against strains of Staphylococcus aureus by measuring MBCs, FBC indexes and by the killing curve technique. Bactericidal titres were determined in sera from volunteers given ofloxacin alone or in combination with fosfomycin or vancomycin. FBC indices less than 0.75 were observed with fosfomycin, showing moderate synergy. FBC indices of 1 were seen with vancomycin. Killing kinetic experiments indicated that ofloxacin (1 and 4 mg/l) exerted a rapid bactericidal effect (99.9% killing in 4 h); the combination of ofloxacin and fosfomycin was synergistic for one of three strains, while killing kinetics of ofloxacin were unaltered by fosfomycin for two of three strains or by vancomycin for the three strains. Sera collected two hours after ofloxacin or fosfomycin had been administered had bactericidal titres less than 1/2. Bactericidal titres were significantly greater in sera from volunteers given the combination of these two drugs. Similar bactericidal titres were obtained in sera after the administration of vancomycin alone or in combination with ofloxacin. A loading dose of 400 mg ofloxacin with subsequent doses of 200 mg had no significantly prolonged effect on bactericidal titres.