This study identified previous history of fracture and remnants of internal fixation as major risk factors of infection after TKA. For clinical relevance, surgeons should be aware of potential infection when performing TKA in patients with these risk factors and patients should be informed of the potential risks.

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Ishii, T. (2006). Phylogenetic relationships of freshwater bryozoans (Ectoprocta, Phylactolaemata) inferred from mitochondrial ribosomal DNA sequences. 35,[243][244][245][246][247][248][249] Most species of freshwater bryozoans (Ectoprocta: Phylactolaemata) have few morphological distinctions, and within phylactolaemates, the morphology of the statoblast has been used to determine evolutionary relationships. Here, two controversial phylogenies have been proposed for phylactolaemates with regard to the relationship of Lophopodidae to other families. Two plumatellid genera, Gelatinella and Hyalinella , are candidates for the ancestral type of lophopodids. In addition, the coexistence of spines on the surfaces of the statoblast has led to the suggestion that lophopodids are closely related to the family Cristatellidae. In this study, we analysed mitochondrial DNA sequences of the 12S and 16S rDNA genes of 10 phylactolaemate species. Our results suggest that plumatellids may not be a direct ancestral group of lophopodids and that cristatellids are not a sister group of lophopodids. Fredericella , which was previously thought to be an ancestral group, was revealed to be derived. In addition, our results suggest that Stephanella is the most basal phylactolaemate. Mapping morphological characteristics onto the sequence-based phylogenetic tree revealed convergent evolution of statoblast characters.

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We assessed 90 total hip arthroplasties (THAs) performed with the Metasul metal-on-metal hip system (Zimmer, Warsaw, Indiana); the patients were monitored for >10 years. The average Harris Hip Score of the patients was 40.5 points preoperatively and 85.8 points at final follow-up. No adverse reactions to the metal debris were observed in patients presenting with symptoms or phenomena such as unexplained pain, joint effusion, bursitis, or pseudotumor. Radiographically, the acetabular component fixation was stable in 86 hips, possibly unstable in 3 hips, and unstable in 1 hip. The unstable hip required revision of the acetabular component. The femoral component was bone-ingrown in 81 hips and stable-fibrous in 9 hips. Distal femoral cortical hypertrophy was seen in 34.4% of hips.Postoperatively, 6 hips dislocated, of which 2 developed recurrent dislocation and required revision of the acetabular component. Dissociation of the polyethylene liner occurred in 2 hips 6 and 12 years postoperatively, respectively, and required revision of the polyethylene liner and the articular head. The survival rate with the endpoint defined as revision surgery and radiologic loosening was 94.4% at mean follow-up (12.3 years). This study found that the Metasul metal-on-metal THA produces excellent long-term results.

We compared the results of 1-stage uncemented bilateral total hip arthroplasty (THA) performed in 49 patients (98 hips) with those of 2-stage uncemented bilateral THA performed during the same hospital stay in 40 patients (80 hips). There was no significant difference in mean Harris Hip Score preoperatively and at final follow-up between the 2 groups. Radiographic evaluation of patients in the 1-stage group revealed the acetabular component was stable in 95 hips and possibly unstable in 3. The femoral component was bone-ingrown in 91 hips and stable fibrous in 7. In the 2-stage group, the acetabular component was stable in 77 hips and possibly unstable in 3. The femoral component was bone-ingrown in 71 hips and stable fibrous in 9. In both groups, no patients exhibited clear signs of loosening, migration or osteolysis.In the 1-stage group, postoperative dislocation occurred in 2 hips and 1 patient had developed deep venous thrombosis and pulmonary embolism. In the 2-stage group, no complications were observed. The incidence of complications was not significantly different between the 2 groups.There was no significant difference in the total blood loss and mean hemoglobin level preoperatively and at discharge between the 2 groups. However, in the 1-stage group, operative time, intraoperative blood loss, procedure cost, and hospital stay were significantly reduced compared with the 2-stage group. Therefore, 1-stage bilateral THA is a safe and effective option for patients with significant arthritic disease of both hips.

The colonial ascidian Aplidium yamazii exhibited an allorejection reaction when two allogeneic colonies were brought into contact at their growing edges or at artificial cut surfaces. This species has no vascular network in the tunic, unlike the botryllid ascidians, which have a vascular network throughout the colony's common tunic. In the allorejection reaction induced by contact at the growing edges, some small, hard-packed tunic masses were formed at the contact points. Histological and electron microscopic investigation of these tunic masses revealed that they contained aggregates of tunic cells, with tunic phagocytes being the major cell type present. Some of the tunic phagocytes in these tunic masses appeared to be disintegrating. When allogeneic colonies were placed in contact at their artificial cut surfaces, the colonies partially fused, then separated. In this allorejection reaction, some loosely packed tunic masses remained in the gap between the two withdrawn colonies. These results strongly suggest that the tunic phagocytes are likely to be the major effector cells in the allorejection reaction. We also propose that the tunic phagocytes are not only the effector cells in the allorejection reaction but also bear the sites of allorecognition.

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