J Orthop Case Rep
June 2016
Introduction: The management of patients with coagulopathic disorders undergoing orthopaedic surgery requires a dedicated, multi-disciplinary team with detailed perioperative planning. Bernard-Soulier Syndrome (BSS) is an extremely rare disorder, affecting 1 in 1 million individuals worldwide. It is caused by a deficiency in glycoprotein 1b-V-IX which is required for normal platelet-mediated clot formation.
View Article and Find Full Text PDFObjective: Breakthrough pain is defined as a transient exacerbation of pain that occurs spontaneously or in response to a trigger despite stable and controlled background pain. The purpose of this study was to explore Canadian patients' awareness of and experience with breakthrough pain in cancer (BTPc).
Methods: Four Canadian cancer centers participated in a non-interventional survey recruiting cancer patients who experienced breakthrough pain.
The role of endogenous nitric oxide (NO) in the growth and vascularization of a rat carcinosarcoma (P22) has been investigated. Tumor-bearing animals were treated with (i) nitric oxide synthase (NOS) inhibitors, administered via the drinking water, including N(G)-nitro-l-arginine methyl ester (L-NAME), a nonisoform-selective inhibitor, and 2 others that target the inducible (NOS II) enzyme preferentially, namely 1-amino-2-hydroxyguanidine or N-[3-(aminomethyl)benzyl]acetamidine hydrochloride; or (ii) daily injections (intraperitoneally) of 2 Ru(III) polyaminocarboxylates, AMD6221 and AMD6245, both of which are effective NO scavengers. L-NAME, AMD6221, and AMD6245 reduced tumor growth by approximately 60% to 75% of control rates.
View Article and Find Full Text PDFSpine (Phila Pa 1976)
February 2010
Study Design: This study investigates the effects of photodynamic therapy (PDT) on the structural integrity of vertebral bone in healthy rats.
Objective: To determine the short-term (1 week) and intermediate term (6 weeks) effects of a single PDT treatment on the mechanical and structural properties of vertebral bone.
Summary Of Background Data: Spinal metastasis develops in up to one-third of all cancer patients, compromising the mechanical integrity of the spine and thereby increasing the risk of pathologic fractures and spinal cord damage.
Clin Orthop Relat Res
April 2009
Photodynamic therapy uses nonthermal coherent light delivered via fiber optic cable to locally activate a photosensitive chemotherapeutic agent that ablates tumor tissue. Owing to the limitations of light penetration, it is unknown whether photodynamic therapy can treat large osseous tumors. We determined whether photodynamic therapy can induce necrosis in large osseous tumors, and if so, to quantify the volume of treated tissue.
View Article and Find Full Text PDFThe majority of cancers arise from malignant epithelial cells. We report the design of synthetic oligonucleotides (aptamers) that are only internalized by epithelial cancer cells and can be precisely activated by light to kill such cells. Specifically, phototoxic DNA aptamers were selected to bind to unique short O-glycan-peptide signatures on the surface of breast, colon, lung, ovarian and pancreatic cancer cells.
View Article and Find Full Text PDFBackground And Objectives: This study investigates whether low-level light treatment (LLLT) can enhance the expression of peripheral-type mitochondrial benzodiazepine receptors (PBRs) on glioma-derived tumor cells, and by doing so promote the synthesis of protoporphyrin IX (PpIX) and increase the photodynamic therapy (PDT)-induced cell kill using 5-aminolevulinic acid (ALA). The endogenous photosensitizer, PpIX and related metabolites including coproporphyrin III are known to traffic into or out of the mitochondria via the PBRs situated on the outer mitochondrial membrane. Cells of astrocytic derivation within the brain express PBRs, while neurons express the central-type of benzodiazepine receptor.
View Article and Find Full Text PDFPhotodynamic therapy has been successfully applied to numerous cancers. Its potential to treat cancer metastases in the spine has been demonstrated previously in a preclinical animal model. The aim of this study was to test two photosensitizers, benzoporphyrin-derivative monoacid ring A (BPD-MA) and by 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX), for their potential use to treat bony metastases.
View Article and Find Full Text PDFVascularization of developing growth plates is integral to the process of endochondral ossification. We hypothesized photodynamic therapy could be used to initiate premature vascularization and calcification of growth plates in mice on the induction of vascular endothelial growth factor. Three-week-old transgenic mice that emit bioluminescence on activation of the vascular endothelial growth factor gene were treated with different regimens of benzoporphyrin derivative mono-acid-mediated photodynamic therapy in the right, proximal tibial growth plate.
View Article and Find Full Text PDFUltrasound imaging is proving to be an important tool for medical diagnosis of dermatological disease. Backscatter spectral profiles using high-frequency ultrasound (HFUS, 10-100 MHz) are sensitive to subtle changes in eukaryotic cellular morphology and mechanical properties that are indicative of early apoptosis, the main type of cell death induced following photodynamic therapy (PDT). We performed experiments to study whether HFUS could also be used to discern changes in bacteria following PDT treatment.
View Article and Find Full Text PDFObjective: Photodynamic therapy (PDT) defines the light activation of a photosensitizing compound, leading to the generation of cytotoxic, reactive oxygen species. We are investigating the unique application of PDT for diseased bone.
Methods: Bioluminescent, human breast cancer cells (MT-1) were injected intracardially into athymic rats.
Clin Orthop Relat Res
January 2007
Imaging modalities facilitate the detection of early bony metastases. Few studies specifically address vertebral metastases in animal models for preclinical (early, asymptomatic) disease. We performed intracardiac injection of human breast cancer (MT-1) cells in 35 athymic nude rats.
View Article and Find Full Text PDFOsteomyelitis can lead to severe morbidity and even death resulting from an acute or chronic inflammation of the bone and contiguous structures due to fungal or bacterial infection. Incidence approximates 1 in 1000 neonates and 1 in 5000 children in the United States annually and increases up to 0.36% and 16% in adults with diabetes or sickle cell anaemia, respectively.
View Article and Find Full Text PDFThis study represents the first reported use of photodynamic therapy (PDT) for metastatic bone lesions and specifically, as a treatment for spinal metastases. A model of bone metastasis in rat confirmed the efficacy of benzoporphyrin derivative-monoacid-mediated PDT for treating lesions within the spine and appendicular bone. Fluorimetry confirmed the selective accumulation of drug into the tumor(s) at 3 h post-injection.
View Article and Find Full Text PDFThe feasibility and efficacy of photodynamic therapy (PDT) for the treatment of vertebral metastases using a minimally invasive surgical technique adapted from vertebroplasty was evaluated in a rodent model. Initial validation included photosensitizer (benzoporphyrin-derivative monoacid-ring A) drug uptake studies and in vitro confirmation of PDT efficacy. Intracardiac injection of human MT-1 breast cancer cells was performed in athymic rats.
View Article and Find Full Text PDFFluorescence-guided resection (FGR) and photodynamic therapy (PDT) have previously been investigated separately with the objectives, respectively, of increasing the extent of brain tumour resection and of selectively destroying residual tumour post-resection. Both techniques have demonstrated trends towards improved survival, pre-clinically and clinically. We hypothesize that combining these techniques will further delay tumour re-growth.
View Article and Find Full Text PDFA mobile isocentric C-arm (Siemens PowerMobil) has been modified in our laboratory to include a large area flat-panel detector (in place of the x-ray image intensifier), providing multi-mode fluoroscopy and cone-beam computed tomography (CT) imaging capability. This platform represents a promising technology for minimally invasive, image-guided surgical procedures where precision in the placement of interventional tools with respect to bony and soft-tissue structures is critical. The image quality and performance in surgical guidance was investigated in pre-clinical evaluation in image-guided spinal surgery.
View Article and Find Full Text PDFTOOKAD (WST09) is a new, long-wavelength palladium bacteriopheophorbide photosensitizer that targets tissue vasculature. The cutaneous phototoxicity of TOOKAD was assessed in normal rat and pig animal models and in patients in a Phase-I trial of TOOKAD-mediated photodynamic therapy (PDT) for recurrent prostate cancer. Controlled skin exposures were administered using solar-simulated light at various times after drug administration.
View Article and Find Full Text PDFPhotodynamic therapy (PDT) is a promising modality for the treatment of solid tumors that combines a photosensitizing agent and light to produce cytotoxic reactive oxygen species that lead to tumor cell death. The recent introduction of bioluminescence imaging (BLI), involving the use of the luciferase gene (luc) transferred into target tumor cells, followed by systemic administration of luciferin and detection of the emitted visible chemiluminescence photons, offers the potential for longitudinal imaging of tumor growth and therapeutic response in single animals. We demonstrate in this study the first results of the use of BLI to assess the response of an intracranial brain tumor model (9L rat gliosarcoma) to aminolevulinic acid (ALA)-mediated PDT.
View Article and Find Full Text PDFThe concept of metronomic photodynamic therapy (mPDT) is presented, in which both the photosensitizer and light are delivered continuously at low rates for extended periods of time to increase selective tumor cell kill through apoptosis. The focus of the present preclinical study is on mPDT treatment of malignant brain tumors, in which selectivity tumor cell killing versus damage to normal brain is critical. Previous studies have shown that low-dose PDT using 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) can induce apoptosis in tumor cells without causing necrosis in either tumor or normal brain tissue or apoptosis in the latter.
View Article and Find Full Text PDFPhotodynamic therapy (PDT) relies on three main ingredients, oxygen, light and photoactivating compounds, although the PDT response is definitively contingent on the site and level of reactive oxygen species (ROS) generation. This study describes the development of a novel, fluorescent-based actinometer microsphere system as a means of discerning spatially resolved dosimetry of total fluence and ROS production. Providing a high resolution, localized, in situ measurement of fluence and ROS generation is critical for developing in vivo PDT protocols.
View Article and Find Full Text PDFWe previously described a fiber based Doppler optical coherence tomography system [1] capable of imaging embryo cardiac blood flow at 4~16 frames per second with wide velocity dynamic range [2]. Coupling this system to a linear scanning fiber optical catheter design that minimizes friction and vibrations, we report here the initial results of in vivo endoscopic Doppler optical coherence tomography (EDOCT) imaging in normal rat and human esophagus. Microvascular flow in blood vessels less than 100 microm diameter was detected using a combination of color-Doppler and velocity variance imaging modes, during clinical endoscopy using a mobile EDOCT system.
View Article and Find Full Text PDFA simple synthetic strategy is described to incorporate a protected diaminedithiol (N(2)S(2)) chelator during Fmoc solid-phase synthesis of short peptides. The resulting constructs could be efficiently labeled with technetium-99m (99mTc). The chelator was assembled at the N-terminus of peptides in a two-step procedure where the deprotected terminal amino group was first reacted with di-Fmoc-diaminopropionic acid (Fmoc-DAP-[Fmoc]-OH).
View Article and Find Full Text PDFMethods for delivering drugs into cells remain an important part of the process of designing drugs. One promising approach is the concept of loligomers, synthetic peptides composed of a branched polylysine core harboring identical arms. Loligomers are typically synthesized with eight arms, each carrying peptide signals guiding their import and localization into cells.
View Article and Find Full Text PDFThe success of proteomics hinges in part on the development of approaches able to map receptors on the surface of cells. One strategy to probe a cell surface for the presence of internalized markers is to make use of Shiga-like toxin 1 (SLT-1), a ribosome-inactivating protein that kills eukaryotic cells [1, 2]. SLT-1 binds to the glycolipid globotriaosylceramide [3, 4], which acts as a shuttle, allowing the toxin to be imported and routed near ribosomes.
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