The functional outcome of arthroscopic rotator cuff repair with double-row knotless vs knot-tying anchors.

To date two main techniques are used in arthroscopic full-thickness rotator cuff tears, the conventional knot-tying suture bridge technique and the knotless technique. We evaluated whether there is a difference in clinical outcome using both techniques. Our patients underwent arthroscopic treatment of full-thickness rotator cuff tears, and we retrospectively evaluated clinical function, strength and surgery time. Eighty-three shoulders operated between September 2012 and December 2013 were included in the study. We had nineteen patients in the knotless group, and sixty-four in the knot-tying group. In addition, we performed preoperatively radiological (magnetic resonance imaging-MRI) conformation of full-thickness rotator cuff tear in our patients. For clinical evaluation, we used Quick Disabilities of the Arm, Shoulder and Hand score (q-DASH) and the Shoulder Pain and Disability (SPADI) score, and we measured the strength of a range of motion postoperatively using a conventional dynamometer. The patients were evaluated preoperatively, and at 6, 9, and 12 months postoperatively. The follow-up period was 12 months. The scores in both treatment groups improved at twelve months follow-up, but there was no statistical difference between both groups at twelve months after surgery; q-DASH score between groups (p = 0.092) and SPADI score (p = 0.700). Similarly, there was no statistical difference between the groups in regard to strength, surgery time, and range of motion at the twelve months follow-up. Our data confirm that both techniques may be used successfully to repair full-thickness rotator cuff tears with very good functional outcome.Level of evidence IV.

Local effect of zoledronic acid on new bone formation in posterolateral spinal fusion with demineralized bone matrix in a murine model.

BACKGROUND: Posterolateral spinal fusion is a common orthopaedic surgery performed to treat degenerative and traumatic deformities of the spinal column. In posteriolateral spinal fusion, different osteoinductive demineralized bone matrix products have been previously investigated. We evaluated the effect of locally applied zoledronic acid in combination with commercially available demineralized bone matrix putty on new bone formation in posterolateral spinal fusion in a murine in vivo model. METHODS: A posterolateral sacral spine fusion in murine model was used to evaluate the new bone formation. We used the sacral spine fusion model to model the clinical situation in which a bone graft or demineralized bone matrix is applied after dorsal instrumentation of the spine. In our study, group 1 received decortications only (n = 10), group 2 received decortication, and absorbable collagen sponge carrier, group 3 received decortication and absorbable collagen sponge carrier with zoledronic acid in dose 10 µg, group 4 received demineralized bone matrix putty (DBM putty) plus decortication (n = 10), and group 5 received DBM putty, decortication and locally applied zoledronic acid in dose 10 µg. Imaging was performed using MicroCT for new bone formation assessment. Also, murine spines were harvested for histopathological analysis 10 weeks after surgery. RESULTS: The surgery performed through midline posterior approach was reproducible. In group with decortication alone there was no new bone formation. Application of demineralized bone matrix putty alone produced new bone formation which bridged the S1-S4 laminae. Local application of zoledronic acid to demineralized bone matrix putty resulted in significant increase of new bone formation as compared to demineralized bone matrix putty group alone. CONCLUSIONS: A single local application of zoledronic acid with DBM putty during posterolateral fusion in sacral murine spine model increased significantly new bone formation in situ in our model. Therefore, our results justify further investigations to potentially use local application of zoledronic acid in future clinical studies.

Bacterial reduction and shift with NPWT after surgical debridements: a retrospective cohort study.

BACKGROUND: Surgical debridement, negative-pressure wound therapy (NPWT) and antibiotics are used for the treatment of open wounds. However, it remains unclear whether this treatment regimen is successful in the reduction and shift of the bacterial load. METHODS: After debridement in the operating room, NPWT, and antibiotic treatment, primary and secondary consecutive microbiological samples of 115 patients with 120 open wounds with bacterial or yeast growth in ≥1 swab or tissue microbiological sample(s) were compared for bacterial growth, Gram staining and oxygen use at a level one trauma center in 2011. RESULTS: Secondary samples had significantly less bacterial growth (32 vs. 89%, p < .001, OR 17), Gram-positive bacteria (56 vs. 78%, p = .013), facultative anaerobic bacteria (64 vs. 85%, p = .011) and Staphylococcus aureus (10 vs. 46%, p = .002). They also tended to include relatively more Coagulase-negative Staphylococci (CoNS) (44 vs. 18%) and Pseudomonas species (spp.) (31 vs. 7%). Most (98%) wounds were successfully closed within 11 days, while wound revision was needed in 4%. CONCLUSIONS: The treatment regimen of combined use of repetitive debridement, irrigation and NPWT in an operating room with antibiotics significantly reduced the bacterial load and led to a shift away from Gram-positive bacteria, facultative anaerobic bacteria, and S. aureus, as well as questionably toward CoNS and Pseudomonas spp. in this patient cohort. High rates of wound closure were achieved in a relatively short time with low revision rates. Whether each modality played a role for these findings remains unknown.

Chance fracture in an older patient with positive sagittal imbalance and previous lumbar arthrodesis: what can be done?

The Chance fracture occurs frequently in school-aged patients' population and is related to flexion-distraction injury in motor vehicle accidents. It is so called seat-belt syndrome because the seatbelt lies over the abdomen. After sudden deceleration bends the child around the lap belt causing injuries to the abdomen, and the spine (e.g., Chance fracture). The Chance fracture after a low energy fall in elderly patient's population has rarely been reported. We present an 82 years old patient who suffered unrecognized Chance fracture after a low energy fall. The management of this patient with positive sagittal imbalance and previous arthrodesis consisted of decompression, Smith-Petersen osteotomy and posterior pedicle screw instrumentation.

Acute neck pain caused by atlanto-axial instability secondary to pathologic fracture involving odontoid process and C2 vertebral body: treatment with radiofrequency thermoablation, cement augmentation and odontoid screw fixation.

INTRODUCTION: Cervical spine metastases are relatively rare entities. Only about 10 % of all spinal metastases can be found in this localization. Magnetic resonance imaging and computed tomography are routinely used for early detection. The initial, clinical examination and patients' complaints may not always be very prominent. Treatment of such lesions is very challenging and needs to consider patient's comorbidities, quality of life and life expectation. Surgery for these lesions should always be performed in specialized spine units. CASE PRESENTATION: We present here a clinical history of a 67-year-old male with acutely occurring neck pain and some neck discomfort for last 2 weeks. No previous neck pain history or trauma. There were no neurological symptoms, only a slight tremor in the left upper extremity. The detailed past medical history of the patient revealed chronic obstructive pulmonary disease (COPD), diabetes mellitus (DM type II), and smoking 30-pack-year. The first cervical spine X-ray did not demonstrate any pathological findings. We performed a CT scan, which demonstrated a lytic lesion involving the vertebral body of C2 with collapse of odontoid process and subsequent C1-C2 instability. In the next step, because of no medical history of cancer, we performed CT scan of the chest and abdomen, and found a suspicious mass in the right main bronchus and liver. We suggested a bronchial biopsy of the mass but the patient refused this procedure and requested only surgery for the C2 lesion. The patient underwent the described surgical procedure through high anterior cervical approach. We collected the tissue for histology, and performed radiofrequency thermoablation, cement augmentation, and odontoid screw fixation. The patient made an uneventful recovery and 2 weeks after surgery he was able to start his palliative chemotherapy for bronchial carcinoma, which was diagnosed based on biopsy acquired during this procedure. DISCUSSION: There are no specific guidelines regarding treatment of secondary lesions of C2 with instability at C1-C2 level. We describe here an interesting approach for the management of lytic lesions of C2 which may be used also at other levels of cervical spine. We did not observe any leakage of cement into the spinal canal. This procedure allows for fast recovery of patients, with early unrestricted range of motion, and beginning of early chemotherapy.

PKC-alpha inhibitor MT477 slows tumor growth with minimal toxicity in in vivo model of non-Ras-mutated cancer via induction of apoptosis.

MT477 is a novel thiopyrano[2,3-c]quinoline with anti-cancer activity. The purpose of the present study was to evaluate different doses and treatment schedules of MT477 in an in vivo xenograft model of non-Ras-mutated cancer, as well as determine its biological effects and mechanism of action via the four conventional PKC isoforms: α, ßI, ßII, and γ. Here, we show that MT477 inhibits the activity of PKC-α and its downstream targets, ERK1/2 and Akt, before it has an effect on Ras activity. MT477 treatment of cultured H226 cells induced apoptosis and increased focal cell adhesion and formation of actin stress fibers. H226 tumor size in mice continuously treated with intraperitoneal MT477 (1 mg/kg) was 62.1 ± 15.3% smaller than the average tumor size in control mice. Blood serum chemistry revealed minimal toxicity in mice. Taken together, these results support the conclusion that MT477 acts as a direct PKC-α inhibitor in non-Ras mutated cancer, with maximum effectiveness when given in a continuous treatment schedule.

MT103 inhibits tumor growth with minimal toxicity in murine model of lung carcinoma via induction of apoptosis.

Molecular topology (MT) was used to develop quantitative structure-activity relationship (QSAR) models to screen databases for new anticancer compounds. One of the selected compounds was MT103, an isoborneol derivative, with a promising profile predicted to slow tumor growth through pro-apoptotic signaling and protein kinase C inhibition. We found that MT103 inhibited the growth of a wide variety of cancer cell types as verified by the NCI-60 cancer cell line panel. MTT cell viability assay showed that MT103 inhibited 50% of the growth of HOP-92, ACHN, NCI-H226, MCF-7, and A549 cancer cell lines at much lower concentrations than that required for HUVECs and human fibroblasts. MT103 stimulated apoptosis in NCI-H226 lung carcinoma cells as measured by oligonucleosomal DNA fragmentation. However, protein kinase C was not targeted by MT103, as predicted by in silico modeling. MT103 slowed in vivo tumor growth and metastatic spread of NCI-H226 cells injected subcutaneously into NOD/SCID mice, without eliciting any severe adverse events as monitored by animal survival, blood serum analysis, and histological analysis of organs. Oral administration of MT103 nanoparticles (200 nm in diameter), which were generated with ElectroNanospray™ technology, inhibited in vivo growth of HOP-92 lung carcinoma cells almost as effectively as intraperitoneal injections of cisplatin. Taken together, our study of a novel anti-cancer drug identified using a molecular topology-based approach to drug discovery demonstrates that MT103 has anti-tumor activity in vitro and in vivo, although additional studies are needed to elucidate its mechanism of action.

Extraarticular knee resection for sarcomas with preservation of the extensor mechanism: surgical technique and review of cases.

BACKGROUND: Sarcomas in or contaminating the knee are rare but extremely challenging to treat. Complete resection of the joint is necessary, and often the entire extensor mechanism is removed as well. Reconstruction of the knee is challenging, and the resulting function may be compromised. DESCRIPTION OF TECHNIQUE: We describe a surgical technique of extraarticular resection of the knee while preserving the extensor mechanism combined with prosthetic reconstruction. The medial and lateral retinaculum is prepared such that it allows extraarticular placement of K-wires that are driven through the patella and the proximal tibia, serving as in situ guides for the osteotomies. PATIENTS AND METHODS: We retrospectively reviewed 11 patients with sarcomas contaminating the knee. The minimum followup was 14 months (mean, 38 months; range, 14-80 months). RESULTS: At last followup patients had a mean flexion of 88° (range, 65°-120°). We observed no complications related to the extensor mechanism, and there was one local recurrence. CONCLUSIONS: We believe extraarticular resection of the knee with preservation of the extensor mechanism is a reasonable treatment option for intraarticular sarcomas with functional scores comparable to those for patients having intraarticular resections. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

A suspicious vulvar mass diagnosed as a subpubic cartilaginous cyst.

BACKGROUND: Subpubic cartilaginous cysts were initially described in 1996 with few reports to date. CASE: We describe a 62-year-old woman with a history of breast cancer who presented with a painful, fixed, vulvar mass. MRI revealed an 18 x 10 x 12 mm3 mass extending from the anterior portion of the symphysis pubis without bony involvement. Excision was performed. Histologically, the mass consisted of fibrocartilage with extensive degenerative changes, compatible with a subpubic cartilaginous cyst. Over 24 months later, there has been no recurrence. CONCLUSION: Subpubic cartilaginous cyst is a rare, benign lesion occurring on the vulva and should be considered in the differential diagnosis of a painful, superior vulvar mass.

Local irradiation in combination with bevacizumab enhances radiation control of bone destruction and cancer-induced pain in a model of bone metastases.

Skeletal metastases are a major source of morbidity for cancer patients. The purpose of this study was to evaluate the effects of megavoltage irradiation and antiangiogenic therapy on metastatic bone cancer. A tumor xenograft model was prepared in C3H/Scid mice using 4T1 murine breast carcinoma cells. Twenty-eight mice bearing tumors were treated with either bevacizumab (15 mg/kg), local megavoltage irradiation (30 Gy in 1 fraction), combination of bevacizumab and local megavoltage irradiation or physiologic saline solution (control group). Tumor area, bone destruction, tumor microvessel density, pain-associated behaviors and expression of substance P were assessed. Combined modality treatment reduced the frequency of pain-associated behaviors, decreased levels of nociceptive protein expression in the spinal cord, maintained cortical integrity and decreased the density of microvessels as compared to single modality treatments. We conclude that concurrent antiangiogenic therapy and localized radiotherapy for the treatment of bone metastases warrants further evaluation in human clinical trials.

Enzastaurin renders MCF-7 breast cancer cells sensitive to radiation through reversal of radiation-induced activation of protein kinase C.

Enzastaurin (LY317615.HCI), a protein kinase C (PKC)-beta inhibitor, has a radiosensitising effect on 4T1 murine breast cancer and human glioma cells; however, the exact mechanism of this action has not been evaluated. The present study investigated the effects of enzastaurin and gamma irradiation on PKC activity in MCF-7 human breast cancer cells in vitro and in vivo. Enzastaurin (5 microM) in combination with irradiation (2-8 Gy) produced a synergistic decline in MCF-7 clonogenic cell survival. Analysis of MCF-7 cells stained with Annexin V and 7-aminoactinomycin D showed a dose-dependent increase in apoptosis in response to enzastaurin (3, 5 and 7 microM) and irradiation (10 Gy) compared to irradiation alone. This pro-apoptotic effect was confirmed by increases in caspase-3 and -9 activity. In a MCF-7 xenograft model, irradiation with 25 Gy increased PKC-alpha activity by 2.5-fold compared to untreated controls, whereas PKC-epsilon and -betaII activity was increased by 1.8-fold. Radiation-induced activation of all three anti-apoptotic isoforms of PKC was reversed by pre-treatment with enzastaurin (75 mg/kg, twice daily for 3 days). We conclude that enzastaurin has a radiosensitising effect on MCF-7 human xenograft tumours through the reversal of anti-apoptotic activation of PKC isoforms.

Biology of bone cancer pain.

Bone cancer pain is a devastating manifestation of metastatic cancer. Unfortunately, current therapies can be ineffective, and when they are effective, the duration of the patient's survival typically exceeds the duration of pain relief. New, mechanistically based therapies are desperately needed. Study of experimental animal models has provided insight into the mechanisms that drive bone cancer pain and provides an opportunity for developing targeted therapies. Mechanisms that drive bone cancer pain include tumor-directed osteoclast-mediated osteolysis, tumor cells themselves, tumor-induced nerve injury, stimulation of transient receptor potential vanilloid type 1 ion channel, endothelin A, and host cell production of nerve growth factor. Current and future therapies include external beam radiation, osteoclast-targeted inhibiting agents, anti-inflammatory drugs, transient receptor potential vanilloid type 1 antagonists, and antibody therapies that target nerve growth factor or tumor angiogenesis. It is likely that a combination of these therapies will be superior to any one therapy alone.

Novel cytosine deaminase fusion gene enhances the effect of radiation on breast cancer in bone by reducing tumor burden, osteolysis, and skeletal fracture.

BACKGROUND: Painful breast carcinoma metastases in bone are a common manifestation of malignant disease. Eradication of these tumors can be evasive, and as a result, skeletal morbidity increases with disease progression. EXPERIMENTAL DESIGN: The treatment potential of cytosine deaminase (CD) gene therapy combined with radiation treatment was evaluated in vitro and in vivo using a 4T1 murine breast carcinoma model. 4T1 carcinoma cells were transduced with a fusion gene encoding the extracellular and transmembrane domains of the human nerve growth factor receptor and the cytoplasmic portion of the yeast CD gene (NGFR-CD(y)). RESULTS AND CONCLUSIONS: CD-expressing tumor cells (4TCD(y)) were highly sensitive to treatment by 5-fluorocytosine prodrug (P < 0.0001). 5-Fluorocytosine treatment of 4TCD(y), but not 4T1 cells, enhanced the effects of radiation in vitro (P < 0.0001). 5-Fluorocytosine prodrug treatment also increased the therapeutic potential of radiation in vivo. Mice with 4TCD(y) intrafemoral tumors showed increased effectiveness of radiation based on improved reductions in tumor size, reductions in tumorigenic osteolysis, and a decrease in skeletal fractures (P < 0.01).

Risk factors for prolonged treatment and hospital readmission in 280 cases of negative-pressure wound therapy.

BACKGROUND: There is evidence of certain beneficial effects and increasing understanding of the mechanisms of action of negative-pressure wound therapy (NPWT). However, it is known that prolonged duration of NPWT is associated with increased bacterial growth and efforts should be made to decrease the duration of NPWT. It was the aim of this study to evaluate potential risk factors for the duration, from first application of NPWT to secondary wound closure and to identify factors that increase the rate of hospital readmission. METHODS: In a retrospective cohort study, 261 patients (46 ± 19 years, 70 female) who underwent 280 treatments with NPWT were analysed. Patient-specific and demographic characteristics and the presence of several risk factors were documented. The duration of treatment from first application of NPWT to secondary wound closure, the number of interventions, the duration of hospital stay and the incidence of readmissions due to complications of the wound treated by NPWT were recorded and a risk factor analysis was performed. RESULTS: The median number of NPWT procedures was 2.0 ± 2.0, the duration of NPWT was 6.0 ± 14.7 days and the length of hospital stay was 16.0 ± 27.9 days. Presence of an open fracture (p = .002) and increased age (p = .004) were identified as independent risk factors for a prolonged duration of NPWT. Patients who smoked (p = .001) or patients with alcohol/drug abuse (p = .015) were more likely to return to hospital (smoking: 18 out of 58 cases; alcohol/drug abuse: 7 out of 19 cases). No such association was seen for diabetes (p = .702), peripheral vascular disease (PVD) (p = .052), immunosuppressive medication (p = .187), immunodeficiency (p = .404), trauma (p = .358), infection (p = .298) and open fracture (p = .061). CONCLUSIONS: Patient age and presence of an open fracture are independent predictors of a prolonged duration from first application of NPWT to secondary wound closure. These results should be taken into account for the calculation of average costs and anticipated hospital stay associated with this therapy.

Antineoplastic activity of zoledronic acid and denosumab.

Cancer patients suffer from cancer-induced bone pain, hypercalcemia, and reduced quality of life caused by pathological fractures. Many of these complications related to cancer can be treated, or at least controlled, using new anticancer agents. Recently, two agents used initially to treat osteoporosis demonstrated direct and indirect anticancer activity. In this review, we summarize current knowledge about direct and indirect anticancer activity of zoledronic acid (a third-generation bisphosphonate), and denosumab antibody against RANKL. Zoledronic acid influences the proliferation and viability of tumor cells in vitro, and effectively reduces tumor burden, tumor-induced pain, and tumor growth in vivo. Denosumab is a fully human monoclonal antibody preventing the binding of RANKL to its receptor on osteoclasts' membrane, and through this mechanism inhibits the resorption of the bone. Furthermore, this agent demonstrates direct anticancer activity through the RANKL signaling pathway. Because of these features both drugs may gain broader application for the treatment of cancer patients. However, further pre-clinical and clinical evaluation is needed for both agents to fully assess the antineoplastic mechanisms of activity of both agents.

Therapy of acute and delayed spinal infections after spinal surgery treated with negative pressure wound therapy in adult patients.

We present the results of the treatment of infected primary or delayed spine wounds after spinal surgery using negative pressure wound therapy. In our institution (University Hospital Zurich, Switzerland) nine patients (three women and six men; mean age 68.6, range 43-87 years) were treated in the period between January to December 2011 for non-healing spinal wounds. The treatment consisted of repeated debridements, irrigation and temporary closure with negative pressure wound therapy system. Three patients were admitted with a spinal epidural abscess; two with osteoporotic lumbar fracture; two with pathologic vertebra fracture and spinal cord compression, and two with vertebra fracture after trauma. All nine patients have been treated with antibiotic therapy. In one case the hardware has been removed, in three patients laminectomy was performed without instrumentation, in five patients there was no need to remove the hardware. The average hospital stay was 16.6 days (range 11-30). The average follow-up was 3.8, range 0.5-14 months. The average number of negative pressure wound therapy procedures was three, with the range 1-11. Our retrospective study focuses on the clinical problems faced by the spinal surgeon, clinical outcomes after spinal surgery followed by wound infection, and negative pressure wound therapy. Moreover, we would like to emphasize the importance for the patients and their relatives to be fully informed about the increased complications of surgery and about the limitations of treatment of these wounds with negative pressure wound therapy.

Femoral and obturator nerves palsy caused by pelvic cement extrusion after hip arthroplasty.

Cement extrusion into the pelvis with subsequent palsy of the obturator and femoral nerves is a rare entity after hip replacement surgery. Cemented fixation of the acetabular cup has been considered as a safe and reliable standard procedure with very good long term results. We present a case of fifty year old female patient after hip arthroplasty procedure which suffered an obturator and femoral nerve palsy caused by extrusion of bone cement into the pelvis. Postoperative X-rays and CT-scan of the pelvis demonstrated a huge mass consisted of bone cement in close proximity of femoral and obturator nerves. The surgery charts reported shallow and weak bony substance in postero-superior aspect of the acetabulum. This weak bony acetabular substance may have caused extrusion of bone cement during press-fitting of the polyethylene cup into the acetabulum, and the following damage of the both nerves produced by polymerization of bone cement. The bone cement fragment has been surgically removed 3 weeks after arthroplasty. The female patient underwent intensive postoperative physical therapy and electro stimulation which resulted in full recovery of the patient to daily routine and almost normal electromyography results.

MT477 acts in tumor cells as an AURKA inhibitor and strongly induces NRF-2 signaling.

BACKGROUND: The novel compound thiopyrano [2,3-c]quinoline (MT477) has been shown to exhibit antitumor activity in both in vitro and in vivo studies. The present study examined the expression levels of 10,000 genes and how they changed after MT477 treatment in three cancer cell lines: H226, MDA231 and MiaPaCa-2. Materials and Methods/ RESULTS: Molecular function analysis revealed changes in genes involved in cell death, cell-cycle progression and cellular growth and proliferation in all three cancer cell lines. Canonical pathway analysis showed the involvement of the NRF2-mediated oxidative stress response, glucocorticoid, p53, RXR-VDR, G(1)/S checkpoint regulation, ERK, SAPK/JNK and JAS/Stat signaling. Analysis of 234 kinases and phosphatases using a kinase inhibition assay demonstrated a strong inhibitory effect for MAPK14 (104 ± 2%), AMPK A2/B1/G1 (89%) and FGR (83 ± 2%). AURKA was inhibited at 77 ± 1%. MiaPaCa-2 tumor xenograft studies showed a 49.5 ±1 4.8% inhibitory effect in mice treated with 100 µg/kg MT477 compared to untreated mice (p=0.0021). CONCLUSION: MT477 induces molecular mechanisms related to cell death, survival, and inhibition of cellular growth in vitro and in vivo.

Cytotoxic effect of zoledronic acid-loaded bone cement on giant cell tumor, multiple myeloma, and renal cell carcinoma cell lines.

BACKGROUND: Local recurrence with subsequent osteolysis is a problem after intralesional curettage of giant cell tumor of bone, myeloma, and metastatic carcinoma. The bisphosphonate zoledronic acid (zoledronate) has been shown to reduce osteoclast activity, and its local administration is a potentially attractive therapy, especially for the osteoclast-rich giant cell tumor. The aim of this study was to analyze the elution dynamics of zoledronic acid release from acrylic bone cement and its in vitro antitumor efficacy. METHODS: Various concentrations of zoledronic acid were mixed with bone cement and placed in distilled water. The concentration in the water was measured daily for fourteen days. The cytotoxic effects of the dissolved zoledronic acid on cultures of multiple myeloma, giant cell tumor, and renal cell carcinoma cells were tested with use of the MTT assay (tetrazolium [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] dye) and analyzed according to the zoledronic acid concentration and the elapsed time. RESULTS: The release of zoledronic acid was greatest during the first twenty-four hours for all concentrations and decreased rapidly during the next forty-eight hours to reach a plateau after four days. The proliferation assay (MTT) showed zoledronic acid to have significant cytotoxicity in cultures of stromal giant cell tumor, multiple myeloma, and renal cell carcinoma cells. In addition, zoledronic acid decreased the number of viable tumor cells in a dose-dependent manner. Renal cell carcinoma from bone (RBM1-IT4) and stromal giant cell tumor of bone were more susceptible to zoledronic acid than was multiple myeloma. CONCLUSIONS: The method presented in our study is a reproducible technique for evaluating zoledronic acid elution from bone cement and determining its impact on tumor growth. Zoledronic acid is released from bone cement, remains biologically active despite the polymerization of cement, and inhibits the in vitro growth of cell lines from giant cell tumor of bone, myeloma, and renal cell carcinoma.

Transcription factors down-stream of Ras as molecular indicators for targeting malignancies with oncolytic herpes virus.

Overactivation in Ras signaling has been under intensive study as the molecular basis for development of cancer. Such overactivation can occur in the presence or absence of mutations in Ras gene resulting in activation of a series of down-stream effectors such as transcription factors. Different studies have shown the activation of Ras down-stream effectors in non-Hodgkin lymphoma (NHL) although mutations in Ras are not prevalent in this malignancy. Since overactivation in Ras signaling also increases permissiveness of cancer cells to infection by oncolytic versions of herpes simplex virus (e.g. R3616), we were interested in evaluating the value of transcription factors down-stream of Ras as molecular indicators for permissiveness to herpes therapy. In order to accomplish this, and also to assess the permissiveness of lymphoma cells to infection with R3616, we used NHL cell lines Daudi, Jurkat, NC37, Raji, Ramos and ST486. Once the levels of phosphorylation (activation) of extracellular-signal regulated kinase (ERK, a Ras effector pathway) and its down-stream transcription factor ELK were evaluated, Raji and NC37 showed a significant increase in the phosphorylation levels of both molecules while ATF2 (another transcription factor down-stream of p38-kinase pathway) seemed to be activated in all studied cells. Raji and NC37 cells were also most permissive cells to infection with R3616 while their permissiveness was decreased upon treatment of cells with an inhibitor of ELK-DNA binding portraying ERK/ELK as a suitable predictive indicator for selection of cancer cells with increased sensitivity to R3616. This study, therefore, for the first time documents permissiveness of lymphoma cells to oncolytic herpes viruses and introduces ELK as a suitable factor for predicting tumor susceptibility to these novel anticancer agents.