Total shoulder arthroplasty with the Delta III prosthesis is a salvage procedure for severe shoulder dysfunction caused by an irreparable rotator cuff tear associated with other glenohumeral lesions. Complications were frequent following both primary and revision procedures, but they rarely affected the final outcome. The procedure has a substantial potential to improve the condition of patients with severe shoulder dysfunction, at least in the short term.

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More effective treatment of patients with metastasizing osteosarcoma (OS) with a mean 5-year survival rate of <20% requires more detailed knowledge on the complex mechanisms of metastasis for the design of new drugs, which selectively target metastasizing cells. Moreover, novel diagnostic imaging technology for early detection of metastases is needed. Mouse models, which reproduce human metastasizing OS and allow visualization of single metastatic cells are instrumental for preclinical testing of new pharmaceuticals and diagnostic instruments. Here, the low metastatic Dunn cell line and its highly metastatic LM8 subline, both equipped with a constitutively expressed lacZ gene, were used to improve the well-established OS models in syngeneic C3H mice to achieve ex vivo visualization of single metastatic cells in affected organs by X-gal staining. These models, combined with a technique for in situ high quality lung tissuemaintaining perfusion revealed, as a novel finding, single metastasizing Dunn cells in lung and liver. Importantly, constitutive lacZ gene expression did not affect in vitro and in vivo tumorigenic and metastatic properties of Dunn and LM8 cells. Thus, these improved Dunn and LM8 OS mouse models will in the future serve as a benchmark for the development of new metastasis-targeting drugs and metastasisimaging technology. Keywords: osteosarcoma; metastasis; mouse model; lacZ; lung perfusion; syngeneic; single cell tracking Osteosarcoma (OS) is the most common primary bone tumor and the second most frequent leading cause of cancer-related death in children and young adults. At the time of diagnosis, $20% of OS patients have already developed detectable metastases 1 while 25-50% of patients who initially present with non-metastatic disease subsequently develop metastases.2 Despite substantial improvements in surgery and chemotherapy, which have led to a dramatic increase in the survival of patients with localized disease, the 5-year survival of patients with metastases is still <20-30%.1 Although metastasis of the primary tumor to distant organs is the major cause of death in OS, the molecular mechanisms responsible for this phenomenon are still poorly understood. Moreover, the detection of metastatic cells by radiologic imaging and the success in therapeutic eradication of single metastatic cells remains limited.Mouse models provide comprehensive insights into the complex mechanisms of tumor pathogenesis and metastasis.3 They are therefore often used in in vivo experimental cancer research and for preclinical testing of anti-neoplastic or anti-metastatic drugs. Among several OS mouse models that have been established over the last decades, 4-6 the syngeneic Dunn/LM8 model is one of the most frequently used. It consists of the parental Dunn cell line, originally reported not to form metastases upon subcutaneous inoculation of the cells, and of its highly metastatic subline LM8.7 The LM8 cells were derived from the Dunn cells by eight repetitive cycles of in vivo selection for high metastat...

BACKGROUND: Metastasizing osteosarcoma has a mean 5-year survival rate of only 20% to 30%. Therefore, novel chemotherapeutics for more effective treatment of this disease are required. METHODS: The antineoplastic activity of honokiol, which was demonstrated previously in numerous malignancies, was studied in vivo in C3H mice subcutaneously injected with syngeneic b-galactosidase bacterial gene (lacZ)-expressing LM8 osteosarcoma (LM8-lacZ) cells. In vitro cytotoxic effects of honokiol were investigated in 8 human and 2 murine osteosarcoma cell lines with different in vivo metastatic potential. RESULTS: Seven days after subcutaneous flank injection of LM8-lacZ cells, daily intraperitoneal treatment of mice with 150 mg/kg honokiol reduced the number of micrometastases in the lung by 41% and reduced the number of macrometastases in the lung and liver by 69% and 80%, respectively, compared with control. Primary tumor growth was not inhibited. In osteosarcoma cell lines, honokiol inhibited the metabolic activity with a half-maximal concentration (IC 50 ) between 8.0 lg/mL and 16 lg/mL. Cyclosporin A partially reversed the inhibition of metabolic activity in LM8-lacZ cells. Cell proliferation and wound healing migration of LM8-lacZ cells were inhibited by honokiol with an IC 50 between 5.0 lg/mL and 10 lg/mL. Higher concentrations caused rapid cell death, which was distinct from necrosis, apoptosis, or autophagy but was associated with swelling of the endoplasmic reticulum, cytoplasmic vacuolation, and morphologically altered mitochondria. CONCLUSIONS: Honokiol exhibited prominent antimetastatic activity in experimental osteosarcoma and caused rapid cell death in vitro that was unrelated to necrosis, apoptosis, or autophagy. The authors concluded that honokiol has considerable potential for the treatment of metastasizing osteosarcoma.

Skeletal muscle atrophy and fatty infiltration develop after tendon tearing. The extent of atrophy serves as one prognostic factor for the outcome of surgical repair of rotator cuff tendon tears. We asked whether mRNA of genes involved in regulation of degradative processes leading to muscle atrophy, ie, FOXOs, MSTN, calpains, cathepsins, and transcripts of the ubiquitin-proteasome pathway, are overexpressed in the supraspinatus muscle in patients with and without rotator cuff tears. We evaluated biopsy specimens collected during surgery of 53 consecutive patients with different sizes of rotator cuff tendon tears and six without tears. The levels of corresponding gene transcripts in total RNA extracts were assessed by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Supraspinatus muscle atrophy was assessed by MRI. The area of muscle tissue (or atrophy), decreased (increased) with increasing tendon tear size. The transcripts of CAPN1, UBE2B, and UBE3A were upregulated more than twofold in massive rotator cuff tears as opposed to smaller tears or patients without tears. These atrophy gene products may be involved in cellular processes that impair functional recovery of affected muscles after surgical rotator cuff repair. However, the damaging effects of gene products in their respective proteolytic processes on muscle structures and proteins remains to be investigated.

Osteosarcoma (OS) is the most frequent primary bone tumor. Despite multiagent neoadjuvant chemotherapy, patients with metastatic disease have a poor prognosis. Moreover, currently used chemotherapeutics have severe toxic side effects. Thus, novel agents with improved antimetastatic activity and reduced toxicity are needed. Taurolidine, a broad-spectrum antimicrobial, has recently been shown to have antineoplastic properties against a variety of tumors and low systemic toxicity. Consequently, we investigated in our study the antineoplastic potential of taurolidine against OS in two different mouse models. Although both OS cell lines, K7M2 and LM8, were sensitive for the compound in vitro, intraperitoneal application of taurolidine failed to inhibit primary tumor growth. Moreover, it enhanced the metastatic load in both models 1.7-to 20-fold and caused severe liver deformations and up to 40% mortality. Thus, systemic toxicity was further investigated in tumor-free mice histologically, by electron microscopy and by measurements of representative liver enzymes. Taurolidine dose-dependent fibrous thickening of the liver capsule and adhesions and atrophies of the liver lobes were comparable in healthy and tumor-bearing mice. Liver toxicity was further indicated by up to eightfold elevated levels of the liver enzymes alanine transaminase, aspartate transaminase and GLDH in the circulation. Ultrastructural analysis of affected liver tissue showed swollen mitochondria with cristolysis and numerous lipid vacuoles in the cytoplasm of hepatocytes. The findings of our study question the applicability of taurolidine for OS treatment and may suggest the need for caution regarding the widespread clinical use of taurolidine as an antineoplastic agent.Osteosarcoma (OS), a highly malignant bone tumor, is the second most frequent cause of cancer-related death in children and young adolescents. Metastasis, predominantly to the lung and bone, is detected in $ 20% of OS patients at diagnosis.1 Up to 50% of patients develop metastases after completion of initial therapy. (Neo)-adjuvant chemotherapy introduced in the late 1970s has improved the survival rate of patients with localized disease by more than 50% compared to surgery alone, but patients with metastatic disease continue to have a 5-year survival rate below 30%. 1,2 Current chemotherapeutics approved for clinical use, for example, methotrexate, doxorubicin, cisplatin, etoposide and ifosfamide, cause serious side effects including neurotoxicity, cardiotoxicity, hepatotoxicity, nephrotoxicity, hearing loss, sterility and induction of secondary malignancies (reviewed in Refs. 1 and 2). Consequently, novel compounds for more effective treatment of OS with minimal systemic toxicity are urgently needed.Taurolidine [bis(1,1-dioxoperhydro-1,2,4-thiadizinyl-4)methane], a derivative of the amino acid taurin and broad-spectrum antibiotic, has originally been used for prophylactic intraoperative wound lavage and the treatment of severe surgical infections like peritonitis (reviewed in Ref...

Impaired function of shoulder muscles, resulting from rotator cuff tears, is associated with abnormal deposition of fat in muscle tissue, but corresponding cellular and molecular mechanisms, likely reflected by altered gene expression profiles, are largely unknown. Here, an analysis of muscle gene expression was carried out by semiquantitative RT-PCR in total RNA extracts of supraspinatus biopsies collected from 60 patients prior to shoulder surgery. A significant increase of a-skeletal muscle actin (p ¼ 0.0115) and of myosin heavy polypeptide 1 (p ¼ 0.0147) gene transcripts was observed in parallel with progressive fat deposition in the muscle, assessed on parasagittal T1-weighted turbo-spin-echo magnetic resonance images according to Goutallier. Upregulation of a-skeletal muscle actin and of myosin heavy polypeptide-1 has been reported to be associated with increased muscle tissue metabolism and oxidative stress. The findings of the present study, therefore, challenge the hypothesis that increased fat deposition in rotator cuff muscle after injury reflects muscle degeneration. ß