Photodynamic activation as a molecular switch to promote osteoblast cell differentiation via AP-1 activation

In photodynamic therapy (PDT), cells are impregnated with a photosensitizing agent that is activated by light irradiation, thereby photochemically generating reactive oxygen species (ROS). The amounts of ROS produced depends on the PDT dose and the nature of the photosensitizer. Although high levels of ROS are cytotoxic, at physiological levels they play a key role as second messengers in cellular signaling pathways, pluripotency, and differentiation of stem cells. To investigate further the use of photochemically triggered manipulation of such pathways, we exposed mouse osteoblast precursor cells and rat primary mesenchymal stromal cells to low-dose PDT. Our results demonstrate that low-dose PDT can promote osteoblast differentiation via the activation of activator protein-1 (AP-1). Although PDT has been used primarily as an anti-cancer therapy, the use of light as a photochemical “molecular switch” to promote differentiation should expand the utility of this method in basic research and clinical applications

Knowledge Management Processes and Their Role in Enhancing the Strategic Decision-Making Process - An Applied Study at Al-Azhar University - Gaza

This study aimed to highlight the nature of the relationship between knowledge management and the strategic decision-making process, considering that strategic decisions are formulated and made based on a specific knowledge perspective. The study targeted the university management, deans of faculties, and college directors at Al-Azhar University - Gaza. The study followed a descriptive-analytical approach, and data was collected through a questionnaire designed to cover six dimensions related to knowledge management processes and an axis related to strategic decision-making. The data was analyzed using various statistical methods. The study results showed a statistically significant positive relationship between the role of knowledge management processes and activating the strategic decision-making process at Al-Azhar University - Gaza. The study recommended that the university pay more attention to the processes of knowledge awareness and application as they serve as the link between existing knowledge and the creation of good knowledge. Furthermore, these processes are considered the essential means through which the university improves the effectiveness of strategic decisions and enhances its position

Killing Hypoxic Cell Populations in a 3D Tumor Model with EtNBS-PDT

An outstanding problem in cancer therapy is the battle against treatment-resistant disease. This is especially true for ovarian cancer, where the majority of patients eventually succumb to treatment-resistant metastatic carcinomatosis. Limited perfusion and diffusion, acidosis, and hypoxia play major roles in the development of resistance to the majority of front-line therapeutic regimens. To overcome these limitations and eliminate otherwise spared cancer cells, we utilized the cationic photosensitizer EtNBS to treat hypoxic regions deep inside in vitro 3D models of metastatic ovarian cancer. Unlike standard regimens that fail to penetrate beyond ∼150 µm, EtNBS was found to not only penetrate throughout the entirety of large (>200 µm) avascular nodules, but also concentrate into the nodules' acidic and hypoxic cores. Photodynamic therapy with EtNBS was observed to be highly effective against these hypoxic regions even at low therapeutic doses, and was capable of destroying both normoxic and hypoxic regions at higher treatment levels. Imaging studies utilizing multiphoton and confocal microscopies, as well as time-lapse optical coherence tomography (TL-OCT), revealed an inside-out pattern of cell death, with apoptosis being the primary mechanism of cell killing. Critically, EtNBS-based photodynamic therapy was found to be effective against the model tumor nodules even under severe hypoxia. The inherent ability of EtNBS photodynamic therapy to impart cytotoxicity across a wide range of tumoral oxygenation levels indicates its potential to eliminate treatment-resistant cell populations

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Enhancement of UVB-induced apoptosis by the chemopreventive bioflavonoid apigenin in multiple human keratinocyte models

Dissertation (Ph.D.)--University of Kansas, Pharmacology, Toxicology & Therapeutics, 2007.Topical application of the bioflavonoid apigenin (4',5,7-trihydroxyflavone) to mouse skin effectively reduces incidence and size of skin tumors caused by UVB exposure. The ability to act as a chemopreventive compound indicates that apigenin treatment alters the molecular events initiated by UVB exposure; however, the effects of apigenin treatment on UVB-irradiated keratinocytes are still not fully understood. In the present study, we aimed to study the effect of apigenin treatment and UVB exposure on human keratinocytes and to investigate how apignein may alter the biological consequences of UVB exposure. The experiments described herein, employed three models of human keratinocytes: HaCaT human keratinocyte cells, normal human keratinocytes (NHK) cultures isolated from human neonatal foreskin, and human organotypic keratinocyte cultures (OTKC). The ability of UVB to induce cycloxygenase-2 (COX-2) was investigated due to the role it is thought to play in photocarcinogenesis. The apoptotic response of keratinocytes to UVB is thought to be critical to the development of skin cancer, and therefore was investigated in multiple human keratinocyte models. Each keratinocyte model was exposed to a moderate dose of UVB (300-1000 J/m2), then treated with apigenin (0-50 μM) and harvested to assess apoptosis by Western blot analysis for poly-ADP-ribose polymerase (PARP) cleavage, annexin-V staining by flow cytometry, and/or the presence of sunburn cells. Apigenin treatment enhanced UVB-induced apoptosis more than two-fold in each of the models tested. When keratinocytes were exposed to UVB, apigenin treatment stimulated changes in Bax localization, and increased the release of cytochrome c from the mitochondria compared to UVB exposure alone. Overexpression of the anti-apoptotic protein Bcl-2 and expression of a dominant negative form of Fas-Associated Death Domain (FADDdn) led to a reduction in the ability of apigenin to enhance UVB-induced apoptosis. These results suggest enhancement of UVB-induced apoptosis by apigenin treatment involves both the stress-mediated, intrinsic pathway and the receptor-mediated, extrinsic pathway of apoptosis. The ability of apigenin to enhance UVB-induced apoptosis may explain, in part, the photochemopreventive effects of apigenin

Apigenin Prevents UVB-Induced Cyclooxygenase 2 Expression: Coupled mRNA Stabilization and Translational Inhibition

Cyclooxygenase 2 (COX-2) is a key enzyme in the conversion of arachidonic acid to prostaglandins, and COX-2 overexpression plays an important role in carcinogenesis. Exposure to UVB strongly increased COX-2 protein expression in mouse 308 keratinocytes, and this induction was inhibited by apigenin, a nonmutagenic bioflavonoid that has been shown to prevent mouse skin carcinogenesis induced by both chemical carcinogens and UV exposure. Our previous study suggested that one pathway by which apigenin inhibits UV-induced and basal COX-2 expression is through modulation of USF transcriptional activity in the 5′ upstream region of the COX-2 gene. Here, we found that apigenin treatment also increased COX-2 mRNA stability, and the inhibitory effect of apigenin on UVB-induced luciferase reporter gene activity was dependent on the AU-rich element of the COX-2 3′-untranslated region. Furthermore, we identified two RNA-binding proteins, HuR and the T-cell-restricted intracellular antigen 1-related protein (TIAR), which were associated with endogenous COX-2 mRNA in 308 keratinocytes, and apigenin treatment increased their localization to cell cytoplasm. More importantly, reduction of HuR levels by small interfering RNA inhibited apigenin-mediated stabilization of COX-2 mRNA. Cells expressing reduced TIAR showed marked resistance to apigenin's ability to inhibit UVB-induced COX-2 expression. Taken together, these results indicate that in addition to transcriptional regulation, another mechanism by which apigenin prevents COX-2 expression is through mediating TIAR suppression of translation

Visualizing treatment response dynamics of an in vitro three-dimensional ovarian cancer model

Ovarian epithelial cancer (OVCA) is the fifth leading cause of cancer death among women in the US. The majority of patients have advanced-stage disseminated OVCA that coats the many surfaces in the abdomen with widespread nodular disease. These metastatic lesions often become drug resistant following standard chemotherapy regiments, leading to an unacceptably low survival rate of about 30%. In order to more effectively eradicate this metastatic disease, it is imperative to understand of the dynamics of ovarian tumor treatment response at the cellular and nodular levels. A three-dimensional in vitro model of OVCA developed in our group has proven to be a promising system for visualizing and optimizing the therapy of ovarian nodular disease, enabling studies that would otherwise be implausible to carry out in vivo. Ovarian cancer cells plated on Matrigel spontaneously self-assemble to form a heterogeneous mixture of three-dimensional spheroids that replicate many of the molecular and morphological features observed in avascular micrometastatic nodules found in vivo. Using the non-perturbative three-dimensional structural imaging technology known as optical coherence tomography (OCT), we have observed these nodules to grow beyond 500 µm in diameter and display complex structural changes during development. We have used this model system as a platform for multimodal OCT and fluorescence microscopy experiments aimed at understanding the treatment response of ovarian micronodular disease to cytotoxic therapies. High-throughput confocal fluorescence viability imaging alongside time-lapse OCT experiments revealed that treatments with the front-line chemotherapeutics cisplatin and carboplatin do not effectively kill cells in the center of large (>300 µm diameter) nodules. This three-dimensional pattern of cell death suggests a possible treatment resistance mechanism in vivo. To target this seemingly resistant cell population, we have used photodynamic therapy (PDT), an alternative modality that has been found to be effective against platinum-resistant ovarian cancer. PDT utilizes molecules known as a photosensitizers that, when exposed to a particular wavelength of light, generate cytotoxic reactive oxygen and radical species. We found that treatment using the photosensitizer EtNBS results in effective cellular killing of the previously spared nodule cores. Moreover, when combined with carboplatin, we observed a synergistic treatment response compared to the individual monotherapies alone. Ongoing studies using the 3D model aim to examine the underlying mechanisms behind these treatment responses and will be important in optimizing new therapeutic regimens for metastatic ovarian cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3261. ©2010 American Association for Cancer Researc