148 research outputs found

    Transmorphic phage-guided systemic delivery of TNFα gene for the treatment of human pediatric medulloblastoma

    Get PDF
    Medulloblastoma is the most common childhood brain tumor with an unfavorable prognosis and limited options of harmful treatments that are associated with devastating long-term side effects. Therefore, the development of safe, noninvasive, and effective therapeutic approaches is required to save the quality of life of young medulloblastoma survivors. We postulated that therapeutic targeting is a solution. Thus, we used a recently designed tumor-targeted bacteriophage (phage)-derived particle, named transmorphic phage/AAV, TPA, to deliver a transgene expressing the tumor necrosis factor-alpha (TNFα) for targeted systemic therapy of medulloblastoma. This vector was engineered to display the double-cyclic RGD4C ligand to selectively target tumors after intravenous administration. Furthermore, the lack of native phage tropism in mammalian cells warrants safe and selective systemic delivery to the tumor microenvironment. In vitro RGD4C.TPA.TNFα treatment of human medulloblastoma cells generated efficient and selective TNFα expression, subsequently triggering cell death. Combination with the chemotherapeutic drug cisplatin used clinically against medulloblastoma resulted in augmented effect through the enhancement of TNFα gene expression. Systemic administration of RGD4C.TPA.TNFα to mice-bearing subcutaneous medulloblastoma xenografts resulted in selective tumor homing of these particles and consequently, targeted tumor expression of TNFα, apoptosis, and destruction of the tumor vasculature. Thus, our RGD4C.TPA.TNFα particle provides selective and efficient systemic delivery of TNFα to medulloblastoma, yielding a potential TNFα anti-medulloblastoma therapy while sparing healthy tissues from the systemic toxicity of this cytokine

    Targeting human osteoarthritic chondrocytes with ligand directed bacteriophage-based particles

    Get PDF
    Osteoarthritis (OA) is a degenerative joint disease characterized by progressive deterioration and loss of articular cartilage. There is currently no treatment to reverse the onset of OA. Thus, we developed a targeted delivery strategy to transfer genes into primary human chondrocytes as a proof-of-concept study. We displayed a chondrocyte-affinity peptide (CAP) on the pIII minor coat protein of the M13 filamentous bacteriophage (phage)-based particle carrying a mammalian transgene cassette under cytomegalovirus CMV promoter and inverted terminal repeats (ITRs) cis elements of adeno-associated virus serotype 2 (AAV-2). Primary human articular chondrocytes (HACs) were used as an in vitro model, and the selectivity and binding properties of the CAP ligand in relation to the pathogenic conditions of HACs were characterized. We found that the CAP ligand is highly selective toward pathogenic HACs. Furthermore, the stability, cytotoxicity, and gene delivery efficacy of the CAP-displaying phage (CAP.Phage) were evaluated. We found that the phage particle is stable under a wide range of temperatures and pH values, while showing no cytotoxicity to HACs. Importantly, the CAP.Phage particle, carrying a secreted luciferase (Lucia) reporter gene, efficiently and selectively delivered transgene expression to HACs. In summary, it was found that the CAP ligand preferably binds to pathogenic chondrocytes, and the CAP.Phage particle successfully targets and delivers transgene to HACs

    Validation of the Thai Osteoporosis Foundation and Royal College of Orthopaedic Surgeons of Thailand Clinical Practice Guideline for bone mineral density measurement in postmenopausal women

    Get PDF
    AbstractObjectiveThe primary objective of this study was to determine the sensitivity, specificity, and predictive values of the Thai Osteoporosis Foundation (TOPF) and Royal College of Orthopaedic Surgeons of Thailand (RCOST) Clinical Practice Guideline for bone mineral density (BMD) measurement for the detection of postmenopausal osteoporosis. Its secondary objective was to find better indicators to detect postmenopausal osteoporosis.MethodsPostmenopausal women were enrolled in this study between June and December 2014. The clinical risk factors following TOPF and RCOST Clinical Practice Guideline for BMD measurement were collected. Bone mineral density was measured using dual energy X-ray absorptiometry.ResultsFour hundred postmenopausal women were enrolled in the study. The mean age of the studied population was 66.16 ± 6.04 years. Twenty-seven percent of the participants had either osteoporosis of the lumbar spine, femoral neck, or total hip, of which 13.3% had osteoporosis at the lumbar spine, 21.3% had osteoporosis at the femoral neck, and 2.5% had osteoporosis of the total hip. The sensitivity and specificity for detecting osteoporosis of the whole TOPF and RCOST guideline were 96.2% and 16.7%, 98.8% and 18.7%, 90.0% and 15.1%, and 97.2% and 19.5% at the lumbar spine, femoral neck, total hip, and any sites, respectively. Multiple logistic regression analysis revealed that only OSTA ≤−1, osteopenia on X-ray and low trauma fracture after age of 40 years were significant clinical risk factors in the detection of postmenopausal osteoporosis. The Receiver Operating Characteristics (ROC) curve was used to obtain the optimum probability value of osteoporosis at any sites which revealed that the probability value of 0.2222236 would have a sensitivity of 67% and specificity of 62% as the optimal cut point to detect osteoporosis. A simple flow diagram of “OSTA ≤−1”, “Osteopenia on X-ray” and “A history of low trauma fracture after age of 40 years” was developed as a better trade-off guideline for BMD measurement.ConclusionsThis study revealed that the TOPF and RCOST guideline for BMD measurement provided a high true positive rate of disease detection but with an expense of high false positive rate. The simple flow diagram was proposed as a more appropriate guideline for BMD measurement in postmenopausal women

    Laboratory-grade vs. industrial-grade NaOH as alkaline activator: the properties of coal fly ash based-alkaline activated material for construction

    Get PDF
    Alkaline-activated materials (AAM) are potentially low-carbon alternative binders for the cement industry. Most research studies related to AAM have been performed with high-purity laboratory-grade NaOH alkaline activators (Lab-grade). Gaining confidence in AAM beyond the laboratory scale in real applications remains a major challenge. To make this prospect more realistic, the viability of low-purity industrial-grade (Ind.-grade) and local no-grade alkaline activators was investigated. The strength results of Ind.-grade AAM were 15–20% lower than those of Lab-grade AAM. The purity of the Ind.-grade activator should be at least 98% to achieve the performance of Lab-grade AAM. The production cost of Ind.-grade AAM was 75–85% lower than that of Lab-grade AAM at the same activator concentration. It should be noted that the use of no-grade NaOH is not recommended for engineering purposes due to its uncertain quality and low purity. The combined benefits of low cost and high availability of Ind.-grade activators are expected to enhance the commercial viability of AAM as a sustainable alternative construction material for field applications

    Species composition and population dynamics of phlebotomine sand flies in a Leishmania infected area of Chiang Mai, Thailand

    Get PDF
    Phlebotomine sand flies are established vectors of leishmaniasis in humans. In Thailand, Leishmania martiniquensis and “Leishmania siamensis” have been described as causative agents of leishmaniasis. In this study, a survey of sand flies in the Leishmania infected area of Hang Dong district, Chiang Mai, Thailand was performed using CDC light traps for eight consecutive months, from January to August 2016. A total of 661 sand flies were collected, and of 280 female sand flies, four species of the genus Sergentomyia including Sergentomyia gemmea, S. barraudi, S. indica, and S. hivernus and one species of the genus Phlebotomus, Phlebotomus stantoni, were identified. S. gemmea and S. hivernus were found in Chiang Mai for the first time. The density of captured female sand flies was high in warm and humid periods from June to August, with temperatures of around 26°C and relative humidity about 74%. In addition, S. gemmea was the most predominant species in the area. Further studies as to whether or not these sand fly species could be a vector of Leishmaniasis in Thailand are required

    Didilia sp. Infecting Phlebotomus stantoni in Thailand

    Get PDF
    Nematode infection in wild caught Phlebotomine sand flies was investigated in Thailand. Light microscopy (LM) and scanning electron microscopy (SEM) were used to detect and morphologically characterize entomopathogenic nematodes that presented in the sand flies. Didilia sp. nematodes were found for the first time in the body cavity of wild caught male Phlebotomus stantoni sand flies. The Didilia sp. was identified based on the morphology of the adult nematodes, from their stylet and teeth at the anterior tip, body length, and egg shell sculpture. It was noted that every infected male sand fly had unrotated genitalia, which would not allow them to mate, thus leading to the loss of their offspring. This finding provided information that might lead to study on whether or not the Didilia sp. has the potential to control sand fly population

    Systemically targeted cancer immunotherapy and gene delivery using transmorphic particles

    Get PDF
    Immunotherapy is a powerful tool for cancer treatment, but the pleiotropic nature of cytokines and immunological agents strongly limits clinical translation and safety. To address this unmet need, we designed and characterised a systemically targeted cytokine gene delivery system through transmorphic encapsidation of human recombinant adeno-associated virus DNA using coat proteins from a tumour-targeted bacteriophage (phage). We show that Transmorphic Phage/AAV (TPA) particles provide superior delivery of transgenes over current phage-derived vectors through greater diffusion across the extracellular space and improved intracellular trafficking. We used TPA to target the delivery of cytokine-encoding transgenes for interleukin-12 (IL12), and novel isoforms of IL15 and tumour necrosis factor alpha (TNFα) for tumour immunotherapy. Our results demonstrate selective and efficient gene delivery and immunotherapy against solid tumours in vivo, without harming healthy organs. Our transmorphic particle system provides a promising modality for safe and effective gene delivery, and cancer immunotherapies through cross-species complementation of two commonly used viruses

    Congenital anomalies in low- and middle-income countries: the unborn child of global surgery.

    Get PDF
    Surgically correctable congenital anomalies cause a substantial burden of global morbidity and mortality. These anomalies disproportionately affect children in low- and middle-income countries (LMICs) due to sociocultural, economic, and structural factors that limit the accessibility and quality of pediatric surgery. While data from LMICs are sparse, available evidence suggests that the true human and financial cost of congenital anomalies is grossly underestimated and that pediatric surgery is a cost-effective intervention with the potential to avert significant premature mortality and lifelong disability
    corecore