132 research outputs found

    X-Ray Induced Photodynamic Therapy: A Combination of Radiotherapy and Photodynamic Therapy

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    Conventional photodynamic therapy (PDT)'s clinical application is limited by depth of penetration by light. To address the issue, we have recently developed X-ray induced photodynamic therapy (X-PDT) which utilizes X-ray as an energy source to activate a PDT process. In addition to breaking the shallow tissue penetration dogma, our studies found more efficient tumor cell killing with X-PDT than with radiotherapy (RT) alone. The mechanisms behind the cytotoxicity, however, have not been elucidated. In the present study, we investigate the mechanisms of action of X-PDT on cancer cells. Our results demonstrate that X-PDT is more than just a PDT derivative but is essentially a PDT and RT combination. The two modalities target different cellular components (cell membrane and DNA, respectively), leading to enhanced therapy effects. As a result, X-PDT not only reduces short-term viability of cancer cells but also their clonogenecity in the long-run. From this perspective, X-PDT can also be viewed as a unique radiosensitizing method, and as such it affords clear advantages over RT in tumor therapy, especially for radioresistant cells. This is demonstrated not only in vitro but also in vivo with H1299 tumors that were either subcutaneously inoculated or implanted into the lung of mice. These findings and advances are of great importance to the developments of X-PDT as a novel treatment modality against cancer

    Loss of HIF-1α in endothelial cells disrupts a hypoxia-driven VEGF autocrine loop necessary for tumorigenesis

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    AbstractWe deleted the hypoxia-responsive transcription factor HIF-1α in endothelial cells (EC) to determine its role during neovascularization. We found that loss of HIF-1α inhibits a number of important parameters of EC behavior during angiogenesis: these include proliferation, chemotaxis, extracellular matrix penetration, and wound healing. Most strikingly, loss of HIF-1α in EC results in a profound inhibition of blood vessel growth in solid tumors. These phenomena are all linked to a decreased level of VEGF expression and loss of autocrine response of VEGFR-2 in HIF-1α null EC. We thus show that a HIF-1α-driven, VEGF-mediated autocrine loop in EC is an essential component of solid tumor angiogenesis

    Heparan Sulfate Proteoglycans in Tauopathy

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    Tauopathies are a class of neurodegenerative diseases, including Alzheimer’s disease, and are characterized by intraneuronal tau inclusion in the brain and the patient’s cognitive decline with obscure pathogenesis. Heparan sulfate proteoglycans, a major type of extracellular matrix, have been believed to involve in tauopathies. The heparan sulfate proteoglycans co-deposit with tau in Alzheimer’s patient brain, directly bind to tau and modulate tau secretion, internalization, and aggregation. This review summarizes the current understanding of the functions and the modulated molecular pathways of heparan sulfate proteoglycans in tauopathies, as well as the implication of dysregulated heparan sulfate proteoglycan expression in tau pathology and the potential of targeting heparan sulfate proteoglycan-tau interaction as a novel therapeutic option

    Efficacy of first-line doxorubicin and ifosfamide in myxoid liposarcoma

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    <p>Abstract</p> <p>Background</p> <p>Myxoid liposarcoma (MLS) is a soft tissue sarcoma with adipocytic differentiation characterized by a unique chromosome rearrangement, t(12;16)(q13;p11). The exact efficacy of chemotherapy in MLS has not been clearly established.</p> <p>Patients and methods</p> <p>We retrospectively analyzed the records of 37 histologically confirmed MLS patients who were treated at the University of Texas MD Anderson Cancer Center from January 2000 to December 2009 with doxorubicin 75-90 mg/m<sup>2 </sup>over 72 hours combined with ifosfamide 10 gm/m<sup>2 </sup>in the first-line setting. Response was assessed using RECIST and Choi criteria. The Kaplan-Meier method and log-rank test was used to estimate clinical outcomes.</p> <p>Results</p> <p>The median follow-up period was 50.1 months. The overall response rates were 43.2% using RECIST and 86.5% using the Choi criteria. The 5-year disease-free survival rate was 90% for patients with resectable tumors. Median time to progression and overall survival time for the advanced-disease group were 23 and 31.1 months, respectively.</p> <p>Conclusion</p> <p>Our study demonstrates that doxorubicin-ifosfamide combination therapy has a role in the treatment of MLS. The Choi criteria may be more sensitive in evaluating response to chemotherapy in MLS.</p

    Molecular Basis of NDM-1, a New Antibiotic Resistance Determinant

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    The New Delhi Metallo-ÎČ-lactamase (NDM-1) was first reported in 2009 in a Swedish patient. A recent study reported that Klebsiella pneumonia NDM-1 positive strain or Escherichia coli NDM-1 positive strain was highly resistant to all antibiotics tested except tigecycline and colistin. These can no longer be relied on to treat infections and therefore, NDM-1 now becomes potentially a major global health threat

    Effects of a Pragmatic Home-based Exercise Program Concurrent With Neoadjuvant Therapy on Physical Function of Patients With Pancreatic Cancer: The PancFit Randomized Clinical Trial

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    OBJECTIVE: To determine the effects of a preoperative, home-based exercise program on fitness and physical function in patients with pancreatic cancer. BACKGROUND: We previously established a well-tolerated preoperative exercise program after finding a high frequency of sarcopenia and frailty in patients with pancreatic cancer. METHODS: In this randomized, controlled trial (NCT03187951), patients with pancreatic cancer were randomized to Arm A: enhanced usual care or Arm B: prescribed aerobic and resistance exercise during neoadjuvant therapy. Patients received nutrition counseling and activity trackers. The primary endpoint was 6-minute walk distance (6MWD; ≄14 meters improvement was clinically meaningful). Secondary endpoints included additional physical function tests, health-related quality of life, and clinical outcomes. RESULTS: One hundred fifty-one patients were randomized. Objectively measured weekly activity (153.2±135.6 and 159.8±122.8 min in Arm A and B, respectively, P =0.62) and self-reported weekly moderate-to-strenuous physical activity (107.4±160.4 and 129.6±161.6 min in Arm A and Arm B, respectively, P =0.49) were similar, but weekly strength training sessions increased more in Arm B (by 1.8±1.8 vs 0.1±2.4 sessions, P CONCLUSIONS: In this randomized trial of prescribed exercise versus enhanced usual care during neoadjuvant therapy for pancreatic cancer, a high volume of physical activity and increased exercise capacity were observed in both arms, highlighting the importance of activity among patients preparing for surgery
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