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Sample records for bone preclinical studies

  1. Delivery of small molecules for bone regenerative engineering: preclinical studies and potential clinical applications.

    PubMed

    Laurencin, Cato T; Ashe, Keshia M; Henry, Nicole; Kan, Ho Man; Lo, Kevin W-H

    2014-06-01

    Stimulation of bone regeneration using growth factors is a promising approach for musculoskeletal regenerative engineering. However, common limitations with protein growth factors, such as high manufacturing costs, protein instability, contamination issues, and unwanted immunogenic responses of the host reduce potential clinical applications. New strategies for bone regeneration that involve inexpensive and stable small molecules can obviate these problems and have a significant impact on the treatment of skeletal injury and diseases. Over the past decade, a large number of small molecules with the potential of regenerating skeletal tissue have been reported in the literature. Here, we review this literature, paying specific attention to the prospects for small molecule-based bone-regenerative engineering. We also review the preclinical study of small molecules associated with bone regeneration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Review of Preclinical and Clinical Studies of Bone Marrow-Derived Cell Therapies for Intracerebral Hemorrhage

    PubMed Central

    de Carvalho, Felipe Gonçalves; de Freitas, Gabriel Rodriguez

    2016-01-01

    Stroke is the second leading cause of mortality worldwide, causing millions of deaths annually, and is also a major cause of disability-adjusted life years. Hemorrhagic stroke accounts for approximately 10 to 27% of all cases and has a fatality rate of about 50% in the first 30 days, with limited treatment possibilities. In the past two decades, the therapeutic potential of bone marrow-derived cells (particularly mesenchymal stem cells and mononuclear cells) has been intensively investigated in preclinical models of different neurological diseases, including models of intracerebral hemorrhage and subarachnoid hemorrhage. More recently, clinical studies, most of them small, unblinded, and nonrandomized, have suggested that the therapy with bone marrow-derived cells is safe and feasible in patients with ischemic or hemorrhagic stroke. This review discusses the available evidence on the use of bone marrow-derived cells to treat hemorrhagic strokes. Distinctive properties of animal studies are analyzed, including study design, cell dose, administration route, therapeutic time window, and possible mechanisms of action. Furthermore, clinical trials are also reviewed and discussed, with the objective of improving future studies in the field. PMID:27698671

  3. Preclinical imaging in bone tissue engineering.

    PubMed

    Ventura, Manuela; Boerman, Otto C; de Korte, Chris; Rijpkema, Mark; Heerschap, Arend; Oosterwijk, Egbert; Jansen, John A; Walboomers, X Frank

    2014-12-01

    Since X-rays were discovered, in 1895, and since the first radiological image of a hand, bone tissue has been the subject of detailed medical imaging. However, advances in bone engineering, including the increased complexity of implant scaffolds, currently also underline the limits of X-ray imaging. Therefore, advanced follow-up imaging methods are pivotal to develop. The field of noninvasive, high-sensitivity, and high-resolution anatomical and functional imaging techniques (optical, ultrasound, positron emission tomography, single-photon emission computed tomography, magnetic resonance, etc.) offers a wide variety of tools that potentially could be considered as alternatives, or at least supportive, to the most commonly used X-ray computed tomography. Moreover, dedicated preclinical scanners have become available, with sensitivity and resolution even higher than clinical scanners, thus favoring a quick translation from preclinical to clinical applications. Furthermore, the armamentarium of bone-specific probes and contrast agents for each of this imaging modalities is constantly growing. This review focuses on such preclinical imaging tools, each with its respective strengths and weaknesses, used alone or in combination. Especially, multimodal imaging will dramatically contribute to improve the knowledge on bone healing regenerative processes.

  4. Gallium a unique anti-resorptive agent in bone: Preclinical studies on its mechanisms of action

    SciTech Connect

    Bockman, R.; Adelman, R.; Donnelly, R.; Brody, L.; Warrell, R. ); Jones, K.W. )

    1990-01-01

    The discovery of gallium as a new and unique agent for the treatment of metabolic bone disorders was in part fortuitous. Gallium is an exciting new therapeutic agent for the treatment of pathologic states characterized by accelerated bone resorption. Compared to other therapeutic metal compounds containing platinum or germanium, gallium affects its antiresorptive action without any evidence of a cytotoxic effect on bone cells. Gallium is unique amongst all therapeutically available antiresorptive agents in that it favors bone formation. 18 refs., 1 fig.

  5. Preclinical evaluation of injectable bone substitute materials.

    PubMed

    Bongio, Matilde; van den Beucken, Jeroen J J P; Leeuwenburgh, Sander C G; Jansen, John A

    2015-03-01

    Injectable bone substitutes (IBSs) represent an attractive class of ready-to-use biomaterials, both ceramic- and polymer-based, as they offer the potential benefit of minimally invasive surgery and optimal defect filling. Although in vitro assessments are the first step in the process of development, the safety and efficacy of an IBS strongly depend on validated preclinical research prior to clinical trials. However, the selection of a suitable preclinical model for performance evaluation of an IBS remains a challenge, as no gold standard exists to define the best animal model. In order to succeed in this attempt, we identified three stages of development, including (a) proof-of-principle, (b) predictive validity and (c) general scientific legitimacy, and the respective criteria that should be applied for such selection. The second part of this review provides an overview of commonly used animals for IBSs. Specifically, scientific papers published between January 1996 and March 2012 were retrieved that report the use of preclinical models for the evaluation of IBSs in situations requiring bone healing and bone augmentation. This review is meant not only to describe the currently available preclinical models for IBS application, but also to address critical considerations of such multi-factorial evaluation models (including animal species, strain, age, anatomical site, defect size and type of bone), which can be indicative but in most cases edge away from the human reality. Consequently, the ultimate goal is to guide researchers toward a more careful and meaningful interpretation of the results of experiments using animal models and their clinical applications. Copyright © 2012 John Wiley & Sons, Ltd.

  6. Microrobotized blasting improves the bone-to-textured implant response. A preclinical in vivo biomechanical study.

    PubMed

    Coelho, Paulo G; Gil, Luiz F; Neiva, Rodrigo; Jimbo, Ryo; Tovar, Nick; Lilin, Thomas; Bonfante, Estevam A

    2016-03-01

    This study evaluated the effect of microrobotized blasting of titanium endosteal implants relative to their manually blasted counterparts. Two different implant systems were utilized presenting two different implant surfaces. Control surfaces (Manual) were fabricated by manually grit blasting the implant surfaces while experimental surfaces (Microblasted) were fabricated through a microrobotized system that provided a one pass grit blasting routine. Both surfaces were created with the same ~50µm average particle size alumina powder at ~310KPa. Surfaces were then etched with 37% HCl for 20min, washed, and packaged through standard industry procedures. The surfaces were characterized through scanning electron microscopy (SEM) and optical interferometry, and were then placed in a beagle dog radius model remaining in vivo for 3 and 6 weeks. The implant removal torque was recorded and statistical analysis evaluated implant system and surface type torque levels as a function of time in vivo. Histologic sections were qualitatively evaluated for tissue response. Electron microscopy depicted textured surfaces for both manual and microblasted surfaces. Optical interferometry showed significantly higher Sa, Sq, values for the microblasted surface and no significant difference for Sds and Sdr values between surfaces. In vivo results depicted that statistically significant gains in biomechanical fixation were obtained for both implant systems tested at 6 weeks in vivo, while only one system presented significant biomechanical gain at 3 weeks. Histologic sections showed qualitative higher amounts of new bone forming around microblasted implants relative to the manually blasted group. Microrobotized blasting resulted in higher biomechanical fixation of endosteal dental implants and should be considered as an alternative for impant surface manufacturing. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Extra-oral defect augmentation using autologous, bovine and equine bone blocks: A preclinical histomorphometrical comparative study.

    PubMed

    Moest, Tobias; Wehrhan, Falk; Lutz, Rainer; Schmitt, Christian Martin; Neukam, Friedrich Wilhelm; Schlegel, Karl Andreas

    2015-05-01

    This study aimed to compare autologous bone (AB), bovine bone (BB), and equine bone (EB) blocks with regard to de novo bone formation, connective tissue, and residual bone substitute material portions in a standardized defect animal model. In the frontal skull of 20 pigs, 106 standardized cylindrical "critical size defects" were prepared. Defects were randomly filled with AB, BB, and EB blocks. After a healing period of 30 and 60 days, de novo bone formation, residual bone substitute material, and connective tissue portion was assessed by means of histomorphometry (Toluidine blue O staining). Mann-Whitney U-tests were used to evaluate differences between the groups. The de novo bone formation was significantly higher in the AB group in comparison to the xenogeneic groups (p < 0.05). After 30 days, EB showed significantly (p < 0.05) more newly formed bone compared to the BB group. The soft tissue formation was significantly higher in the BB and EB group. Defects augmented with BB showed significantly (p < 0.05) higher portions of bone substitute materials compared to sides augmented with EB after 30 days. In the extra-oral model, AB blocks were superior concerning de novo bone formation. No clinical advantages of EB blocks could be observed. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  8. Imaging technologies for preclinical models of bone and joint disorders.

    PubMed

    Tremoleda, Jordi L; Khalil, Magdy; Gompels, Luke L; Wylezinska-Arridge, Marzena; Vincent, Tonia; Gsell, Willy

    2011-07-29

    Preclinical models for musculoskeletal disorders are critical for understanding the pathogenesis of bone and joint disorders in humans and the development of effective therapies. The assessment of these models primarily relies on morphological analysis which remains time consuming and costly, requiring large numbers of animals to be tested through different stages of the disease. The implementation of preclinical imaging represents a keystone in the refinement of animal models allowing longitudinal studies and enabling a powerful, non-invasive and clinically translatable way for monitoring disease progression in real time. Our aim is to highlight examples that demonstrate the advantages and limitations of different imaging modalities including magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET), single-photon emission computed tomography (SPECT) and optical imaging. All of which are in current use in preclinical skeletal research. MRI can provide high resolution of soft tissue structures, but imaging requires comparatively long acquisition times; hence, animals require long-term anaesthesia. CT is extensively used in bone and joint disorders providing excellent spatial resolution and good contrast for bone imaging. Despite its excellent structural assessment of mineralized structures, CT does not provide in vivo functional information of ongoing biological processes. Nuclear medicine is a very promising tool for investigating functional and molecular processes in vivo with new tracers becoming available as biomarkers. The combined use of imaging modalities also holds significant potential for the assessment of disease pathogenesis in animal models of musculoskeletal disorders, minimising the use of conventional invasive methods and animal redundancy.

  9. AMT: preclinical pharmacology studies.

    PubMed

    Niazi, Faiz; Drevs, Joachim; Diergarten, Klaus; Dorn, Annette; Maier, Armin; Fiebig, Heinz Herbert; Bruyns, Eddy; Scheele, Jürgen

    2009-05-01

    Auron-Misheil-Therapy (AMT) consisting of aqueous camomile extract supplemented with calcium, vitamins, the antihistamine chlorpheniramine and human insulin is under development as anti-cancer treatment. AMT was preclinically investigated in tumour cell lines and tumour xenografts to guide clinical phase I/II studies. AMT was tested against 56 human tumour cell lines, in a clonogenic assay in 98 patient-derived xenografts and in in vivo studies. AMT showed in vitro cytotoxic activity with highest susceptibility in cervical cancer, glioblastoma and colon cancers. In the clonogenic assay, anti- cancer activity of AMT was most active in cervical and uterine tumours, in colon cancer, glioblastoma, leukaemia, melanoma and pancreatic cancer. In vivo, AMT showed slight activity in tumour xenograft models of colon and mammary cancer. It also showed immune stimulatory effects by induction of IL-6- and TNF-alpha secretion in human PBMCs. The immune stimulatory potential of AMT, together with slight anti-tumour efficacy observed in the present study, indicates a role of AMT in tumour therapy.

  10. In-Vivo Efficacy of Compliant 3D Nano-Composite in Critical-Size Bone Defect Repair: a Six Month Preclinical Study in Rabbit

    PubMed Central

    Sagar, Nitin; Pandey, Alok K.; Gurbani, Deepak; Khan, Kainat; Singh, Dhirendra; Chaudhari, Bhushan P.; Soni, Vivek P.; Chattopadhyay, Naibedya; Dhawan, Alok; Bellare, Jayesh R.

    2013-01-01

    Bone defects above critical size do not heal completely by itself and thus represent major clinical challenge to reconstructive surgery. Numerous bone substitutes have already been used to promote bone regeneration, however their use, particularly for critical-sized bone defects along with their long term in vivo safety and efficacy remains a concern. The present study was designed to obtain a complete healing of critical-size defect made in the proximal tibia of New Zealand White rabbit, using nano-hydroxyapatite/gelatin and chemically carboxymethylated chitin (n-HA/gel/CMC) scaffold construct. The bone-implant interfaces and defect site healing was evaluated for a period up to 25 weeks using radiography, micro-computed tomography, fluorescence labeling, and histology and compared with respective SHAM (empty contra lateral control). The viscoelastic porous scaffold construct allows easy surgical insertion and post-operatively facilitate oxygenation and angiogenesis. Radiography of defect treated with scaffold construct suggested expedited healing at defect edges and within the defect site, unlike confined healing at edges of the SHAM sites. The architecture indices analyzed by micro-computed tomography showed a significant increase in percentage of bone volume fraction, resulted in reconciled cortico-trabecular bone formation at n-HA/gel/CMC constructs treated site (15.2% to 52.7%) when compared with respective SHAM (10.2% to 31.8%). Histological examination and fluorescence labeling revealed that the uniformly interconnected porous surface of scaffold construct enhanced osteoblasts’ activity and mineralization. These preclinical data suggest that, n-HA/gel/CMC construct exhibit stimulation of bone's innate regenerative capacity, thus underscoring their use in guided bone regeneration. PMID:24204879

  11. Statistical considerations for preclinical studies.

    PubMed

    Aban, Inmaculada B; George, Brandon

    2015-08-01

    Research studies must always have proper planning, conduct, analysis and reporting in order to preserve scientific integrity. Preclinical studies, the first stage of the drug development process, are no exception to this rule. The decision to advance to clinical trials in humans relies on the results of these studies. Recent observations show that a significant number of preclinical studies lack rigor in their conduct and reporting. This paper discusses statistical aspects, such as design, sample size determination, and methods of analyses, that will help add rigor and improve the quality of preclinical studies.

  12. [Development and preclinical studies of insulating membranes based on poly-3-hydroxybutyrate-co-3-hydroxyvalerate for guided bone regeneration].

    PubMed

    Ivanov, S Yu; Bonartsev, A P; Gazhva, Yu V; Zharkova, I I; Mukhametshin, R F; Mahina, T K; Myshkina, V L; Bonartseva, G A; Voinova, V V; Andreeva, N V; Akulina, E A; Kharitonova, E S; Shaitan, K V; Muraev, A A

    2015-01-01

    Bone tissue damages are one of the dominant causes of temporary disability and developmental disability. Currently, there are some methods of guided bone regeneration employing different osteoplastic materials and insulation membranes used in surgery. In this study, we have developed a method of preparation of porous membranes from the biopolymer poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), produced by a strain of Azotobacter chroococcum 7B. The biocompatibility of the porous membranes was investigated in vitro using mesenchymal stem cells (MSCs) and in vivo on laboratory animals. The cytotoxicity test showed the possibility of cell attachment on membrane and histological studies confirmed good insulating properties the material. The data obtained demonstrate the high biocompatibility and the potential application of insulating membranes based on PHBV in bone tissue engineering.

  13. Comparison of bone marrow cells harvested from various bones of cynomolgus monkeys at various ages by perfusion or aspiration methods: a preclinical study for human BMT.

    PubMed

    Kushida, Taketoshi; Inaba, Muneo; Ikebukuro, Kazuya; Ichioka, Naoya; Esumi, Takashi; Oyaizu, Haruki; Yoshimura, Tomoo; Nagahama, Takashi; Nakamura, Kouichi; Ito, Tomoki; Hisha, Hiroko; Sugiura, Kikuya; Yasumizu, Ryoji; Iida, Hirokazu; Ikehara, Susumu

    2002-01-01

    Using cynomolgus monkeys, we have previously established a new method for harvesting bone marrow cells (BMCs) with minimal contamination of the BMCs with T cells from the peripheral blood. We originally conducted this new "perfusion method" in the long bones (the humerus, femur, and tibia) of cynomolgus monkeys. Here, we apply the perfusion method to obtain BMCs from the ilium of cynomolgus monkeys, since BMCs are usually collected from the ilium by the conventional aspiration method in humans. The perfusion method consists of two approaches: transverse iliac perfusion and longitudinal iliac perfusion. BMCs harvested by the perfusion method from the long bones and ilium were compared with those collected from the ilium by the aspiration method. The contamination of BMCs with peripheral blood, determined by the frequencies of CD4+ and CD8+ T cells, was significantly lower in BMCs obtained from the ilium or long bones by the perfusion method (CD4+ plus CD8+ T cells <4%) than in those obtained by the iliac aspiration method (CD4+ plus CD8+ T cells >20%). However, the numbers of immature myeloid cells, such as myeloblasts, promyelocytes, myelocytes, and metamyelocytes, were higher in BMCs obtained by the iliac perfusion method than in those obtained by the iliac aspiration method. The assays for in vitro colony-forming unit in culture revealed that progenitor activity was significantly higher in BMCs obtained by the perfusion method than in those obtained by the aspiration method. These findings suggest that the contamination of BMCs with peripheral blood is much less when using the perfusion method than when using the aspiration method. To determine the best site for harvesting BMCs by the perfusion method, age-dependent changes in BMCs harvested by the perfusion method from the long bones and ilium were examined. The numbers of BMCs varied in the long bones (humerus > femur > tibia) and showed age-dependent decreases, whereas they remained similar in the ilium of

  14. [Preclinical study of noopept toxicity].

    PubMed

    Kovalenko, L P; Smol'nikova, N M; Alekseeva, S V; Nemova, E P; Sorokina, A V; Miramedova, M G; Kurapova, S P; Sidorina, E I; Kulakova, A V; Daugel'-Dauge, N O

    2002-01-01

    Within the framework of a preclinical investigation, the new nootrope drug noopept (N-phenyl-acetyl-L-propyl-glycine ethylate) was tested for chronic toxicity upon peroral administration in a dose of 10 or 100 mg/kg over 6 months in both male and female rabbits. The results of observations showed that noopept administered in this dose range induced no irreversible pathologic changes in the organs and systems studied and exhibited no allergenic, immunotoxic, and mutagen activity. The drug affected neither the generative function nor the antenatal or postnatal progeny development. Noopept produced a dose-dependent suppression of inflammation reaction to concanavalin A and stimulated the cellular and humoral immune response in mice.

  15. PET Tracer 18F-Fluciclovine Can Detect Histologically Proven Bone Metastatic Lesions: A Preclinical Study in Rat Osteolytic and Osteoblastic Bone Metastasis Models

    PubMed Central

    Oka, Shuntaro; Kanagawa, Masaru; Doi, Yoshihiro; Schuster, David M.; Goodman, Mark M.; Yoshimura, Hirokatsu

    2017-01-01

    18F-Fluciclovine (trans-1-amino-3-18F-fluorocyclobutanecarboxylic acid; anti-18F-FACBC) is a positron emission tomography (PET) tracer for diagnosing cancers (e.g., prostate and breast cancer). The most frequent metastatic organ of these cancers is bone. Fluciclovine-PET can visualize bony lesions in clinical practice; however, such lesions have not been described histologically. Methods: We investigated the potential of 14C-fluciclovine in aiding the visualization of osteolytic and osteoblastic bone metastases (with histological analyses), compared with 3H-2-deoxy-2-fluoro-D-glucose (3H-FDG), 3H-choline chloride (3H-choline), and 99mTc-hydroxymethylene diphosphonate (99mTc-HMDP) by using triple-tracer autoradiography in rat breast cancer osteolytic (on day 12 ± 1 postinjection of MRMT-1) and prostate cancer osteoblastic (on day 20 ± 3 postinjection of AT6.1) metastatic models. Results: The distribution patterns of 14C-fluciclovine, 3H-FDG, and 3H-choline, but not 99mTc-HMDP, were similar in both models, and the lesions where these tracers accumulated were, histologically, typical osteolytic and osteoblastic lesions. 99mTc-HMDP accumulated mostly in osteoblastic lesions. 14C-fluciclovine could visualize the osteolytic lesions as early as day 6 postinjection of MRMT-1. However, differential distributions in 14C-fluciclovine and 3H-FDG existed, based on histological differences: low 14C-fluciclovine and high 3H-FDG accumulation in osteolytic lesions with inflammation. In the osteoblastic metastatic model, visualization of osteoblastic lesions with 14C-fluciclovine was not clear, yet clearer than with 3H-FDG. Although half of the osteoblastic lesions with 14C-fluciclovine accumulation showed negligible 3H-choline accumulation in comparison, they were histologically similar to lesions with marked 14C-fluciclovine and 3H-choline accumulation. Conclusion: These results suggest that fluciclovine-PET can visualize true osteolytic and osteoblastic bone metastatic lesions

  16. Monitoring Healing Progression and Characterizing the Mechanical Environment in Preclinical Models for Bone Tissue Engineering.

    PubMed

    Fountain, Stephanie; Windolf, Markus; Henkel, Jan; Tavakoli, Aramesh; Schuetz, Michael A; Hutmacher, Dietmar W; Epari, Devakara R

    2015-12-15

    The treatment of large segmental bone defects remains a significant clinical challenge. Due to limitations surrounding the use of bone grafts, tissue-engineered constructs for the repair of large bone defects could offer an alternative. Before translation of any newly developed tissue engineering (TE) approach to the clinic, efficacy of the treatment must be shown in a validated preclinical large animal model. Currently, biomechanical testing, histology, and microcomputed tomography are performed to assess the quality and quantity of the regenerated bone. However, in vivo monitoring of the progression of healing is seldom performed, which could reveal important information regarding time to restoration of mechanical function and acceleration of regeneration. Furthermore, since the mechanical environment is known to influence bone regeneration, and limb loading of the animals can poorly be controlled, characterizing activity and load history could provide the ability to explain variability in the acquired data sets and potentially outliers based on abnormal loading. Many approaches have been devised to monitor the progression of healing and characterize the mechanical environment in fracture healing studies. In this article, we review previous methods and share results of recent work of our group toward developing and implementing a comprehensive biomechanical monitoring system to study bone regeneration in preclinical TE studies.

  17. Preclinical mouse models for assessing axial compression of long bones during exercise

    PubMed Central

    Stadelmann, Vincent A; Brun, Julia; Bonnet, Nicolas

    2015-01-01

    The aim of this laboratory method is to describe two approaches for the investigation of bone responses to mechanical loading in mice in vivo. The first is running exercise, because it is easily translatable clinically, and the second is axial compression of the tibia, because it is precisely controllable. The effects of running exercise, and in general physical activity, on bone tissue have been shown to be both direct through mechanical loading (ground impact and muscle tension) and indirect through metabolic changes. Therefore, running exercise has been considered the most convenient preclinical model for demonstrating the general idea that exercise is good for bone health, either early in age for increasing peak bone mass or later in age by slowing down bone loss. However, numerous combinations of protocols have been reported, which makes it difficult to formulate a simple take-home message. This laboratory method also provides a detailed description of in vivo direct mechanical axial compression of the mouse tibia. The effects of mechanical loading depend on the force (strain), frequency, waveform and duration of application, and they range from bone anabolism with low bone remodeling, inducing lamellar bone accumulation, to bone catabolism with high bone remodeling, leading to microdamage, woven bone formation and bone loss. Direct in vivo loading models are extensively used to study mechanotransduction pathways, and contribute by this way to the development of new bone anabolism treatments. Although it is particularly difficult to assemble an internationally adopted protocol description, which would give reproducible bone responses, here we have attempted to provide a comprehensive guide for best practice in performing running exercise and direct in vivo mechanical loading in the laboratory. PMID:26788286

  18. Preclinical mouse models for assessing axial compression of long bones during exercise.

    PubMed

    Stadelmann, Vincent A; Brun, Julia; Bonnet, Nicolas

    2015-01-01

    The aim of this laboratory method is to describe two approaches for the investigation of bone responses to mechanical loading in mice in vivo. The first is running exercise, because it is easily translatable clinically, and the second is axial compression of the tibia, because it is precisely controllable. The effects of running exercise, and in general physical activity, on bone tissue have been shown to be both direct through mechanical loading (ground impact and muscle tension) and indirect through metabolic changes. Therefore, running exercise has been considered the most convenient preclinical model for demonstrating the general idea that exercise is good for bone health, either early in age for increasing peak bone mass or later in age by slowing down bone loss. However, numerous combinations of protocols have been reported, which makes it difficult to formulate a simple take-home message. This laboratory method also provides a detailed description of in vivo direct mechanical axial compression of the mouse tibia. The effects of mechanical loading depend on the force (strain), frequency, waveform and duration of application, and they range from bone anabolism with low bone remodeling, inducing lamellar bone accumulation, to bone catabolism with high bone remodeling, leading to microdamage, woven bone formation and bone loss. Direct in vivo loading models are extensively used to study mechanotransduction pathways, and contribute by this way to the development of new bone anabolism treatments. Although it is particularly difficult to assemble an internationally adopted protocol description, which would give reproducible bone responses, here we have attempted to provide a comprehensive guide for best practice in performing running exercise and direct in vivo mechanical loading in the laboratory.

  19. Pre-clinical characterization of tissue engineering constructs for bone and cartilage regeneration.

    PubMed

    Trachtenberg, Jordan E; Vo, Tiffany N; Mikos, Antonios G

    2015-03-01

    Pre-clinical animal models play a crucial role in the translation of biomedical technologies from the bench top to the bedside. However, there is a need for improved techniques to evaluate implanted biomaterials within the host, including consideration of the care and ethics associated with animal studies, as well as the evaluation of host tissue repair in a clinically relevant manner. This review discusses non-invasive, quantitative, and real-time techniques for evaluating host-materials interactions, quality and rate of neotissue formation, and functional outcomes of implanted biomaterials for bone and cartilage tissue engineering. Specifically, a comparison will be presented for pre-clinical animal models, histological scoring systems, and non-invasive imaging modalities. Additionally, novel technologies to track delivered cells and growth factors will be discussed, including methods to directly correlate their release with tissue growth.

  20. Pre-clinical characterization of tissue engineering constructs for bone and cartilage regeneration

    PubMed Central

    Trachtenberg, Jordan E.; Vo, Tiffany N.; Mikos, Antonios G.

    2014-01-01

    Pre-clinical animal models play a crucial role in the translation of biomedical technologies from the bench top to the bedside. However, there is a need for improved techniques to evaluate implanted biomaterials within the host, including consideration of the care and ethics associated with animal studies, as well as the evaluation of host tissue repair in a clinically relevant manner. This review discusses non-invasive, quantitative, and real-time techniques for evaluating host-materials interactions, quality and rate of neotissue formation, and functional outcomes of implanted biomaterials for bone and cartilage tissue engineering. Specifically, a comparison will be presented for pre-clinical animal models, histological scoring systems, and non-invasive imaging modalities. Additionally, novel technologies to track delivered cells and growth factors will be discussed, including methods to directly correlate their release with tissue growth. PMID:25319726

  1. Preclinical Models for Skeletal Research: How Commonly Used Species Mimic (or Don't) Aspects of Human Bone.

    PubMed

    Allen, Matthew R

    2017-01-01

    Preclinical studies play an indispensable role in exploring the biological regulation of the musculoskeletal system. They are required in all drug development pipelines where both small and large animal models are needed to understand efficacy and side effects. This brief review highlights 4 aspects of human bone, longitudinal bone growth, intracortical remodeling, collagen/mineral interface, and age-related changes, and discusses how various animal models recapitulate (or don't) these aspects of human skeletal physiology.

  2. Preclinical evidence of potential craniofacial adverse effect of zoledronic acid in pediatric patients with bone malignancies.

    PubMed

    Lézot, Frédéric; Chesneau, Julie; Battaglia, Séverine; Brion, Régis; Castaneda, Beatriz; Farges, Jean-Christophe; Heymann, Dominique; Rédini, Françoise

    2014-11-01

    High doses of zoledronic acid (ZOL), one of the most potent inhibitors of bone resorption, are currently evaluated in phase III clinical trials in Europe for the treatment of malignant pediatric primary bone tumors. The impact of such an intensive treatment on the craniofacial skeleton growth is a critical question in the context of patients with actively growing skeleton; in particular, in light of our previous studies evidencing that endochondral bone formation was transiently disturbed by high doses of ZOL. Two protocols adapted from pediatric treatments were developed for newborn mice (a total of 5 or 10 injections of ZOL 50μg/kg every two days). Their impact on skull bones and teeth growth was analyzed by X-rays, microCT and histology up to 3months after the last injection. ZOL administrations induced a transient delay of skull bone growth and an irreversible delay in incisor, first molar eruption and root elongation. Other teeth were affected, but most were erupted by 3months. Root histogenesis was severely impacted for all molars and massive odontogenic tumor-like structures were observed in all mandibular incisors. High doses of ZOL irreversibly disturbed teeth eruption and elongation, and delayed skull bone formation. These preclinical observations are essential for the follow-up of onco-pediatric patients treated with ZOL.

  3. Cell Cotransplantation Strategies for Vascularized Craniofacial Bone Tissue Engineering: A Systematic Review and Meta-Analysis of Preclinical In Vivo Studies.

    PubMed

    Shanbhag, Siddharth; Pandis, Nikolaos; Mustafa, Kamal; Nyengaard, Jens R; Stavropoulos, Andreas

    2016-11-01

    The regenerative potential of tissue-engineered bone constructs may be enhanced by in vitro coculture and in vivo cotransplantation of vasculogenic and osteogenic (progenitor) cells. The objective of this study was to systematically review the literature to answer the focused question: In animal models, does cotransplantation of osteogenic and vasculogenic cells enhance bone regeneration in craniofacial defects, compared with solely osteogenic cell-seeded constructs? Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, electronic databases were searched for controlled animal studies reporting cotransplantation of endothelial cells (ECs) with mesenchymal stem cells (MSCs) or osteoblasts in craniofacial critical size defect (CSD) models. Twenty-two studies were included comparing outcomes of MSC/scaffold versus MSC+EC/scaffold (co)transplantation in calvarial (n = 15) or alveolar (n = 7) CSDs of small (rodents, rabbits) and large animal (minipigs, dogs) models. On average, studies presented with an unclear to high risk of bias. MSCs were derived from autologous, allogeneic, xenogeneic, or human (bone marrow, adipose tissue, periosteum) sources; in six studies, ECs were derived from MSCs by endothelial differentiation. In most studies, MSCs and ECs were cocultured in vitro (2-17 days) before implantation. Coculture enhanced MSC osteogenic differentiation and an optimal MSC:EC seeding ratio of 1:1 was identified. Alloplastic copolymer or composite scaffolds were most often used for in vivo implantation. Random effects meta-analyses were performed for histomorphometric and radiographic new bone formation (%NBF) and vessel formation in rodents' calvarial CSDs. A statistically significant benefit in favor of cotransplantation versus MSC-only transplantation for radiographic %NBF was observed in rat calvarial CSDs (weighted mean difference 7.80% [95% confidence interval: 1.39-14.21]); results for histomorphometric %NBF

  4. A reproducible method for the isolation and expansion of ovine mesenchymal stromal cells from bone marrow for use in regenerative medicine preclinical studies.

    PubMed

    Caminal, Marta; Vélez, Roberto; Rabanal, Rosa Maria; Vivas, Daniel; Batlle-Morera, Laura; Aguirre, Màrius; Barquinero, Jordi; García, Joan; Vives, Joaquim

    2016-11-18

    The use of multipotent mesenchymal stromal cells (MSCs) as candidate medicines for treating a variety of pathologies is based on their qualities as either progenitors for the regeneration of damaged tissue or producers of a number of molecules with pharmacological properties. Preclinical product development programmes include the use of well characterized cell populations for proof of efficacy and safety studies before testing in humans. In the field of orthopaedics, an increasing number of translational studies use sheep as an in vivo test system because of the similarities with humans in size and musculoskeletal architecture. However, robust and reproducible methods for the isolation, expansion, manipulation and characterization of ovine MSCs have not yet been standardised. The present study describes a method for isolation and expansion of fibroblastic-like, adherent ovine MSCs that express CD44, CD90, CD140a, CD105 and CD166, and display trilineage differentiation potential. The 3-week bioprocess proposed here typically yielded cell densities of 1.4 × 10(4) MSCs/cm(2) at passage 2, with an expansion factor of 37.8 and approximately eight cumulative population doublings. The osteogenic potential of MSCs derived following this methodology was further evaluated in vivo in a translational model of osteonecrosis of the femoral head, in which the persistence of grafted cells in the host tissue and their lineage commitment into osteoblasts and osteocytes was demonstrated by tracking enhanced green fluorescent protein-labelled cells. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Preclinical studies of low back pain

    PubMed Central

    2013-01-01

    Chronic low back pain is a major cause of disability and health care costs. Current treatments are inadequate for many patients. A number of preclinical models have been developed that attempt to mimic aspects of clinical conditions that contribute to low back pain. These involve application of nucleus pulposus material near the lumbar dorsal root ganglia (DRG), chronic compression of the DRG, or localized inflammation of the DRG. These models, which are primarily implemented in rats, have many common features including behavioral hypersensitivity of the hindpaw, enhanced excitability and spontaneous activity of sensory neurons, and locally elevated levels of inflammatory mediators including cytokines. Clinically, epidural injection of steroids (glucocorticoids) is commonly used when more conservative treatments fail, but clinical trials evaluating these treatments have yielded mixed results. There are relatively few preclinical studies of steroid effects in low back pain models. One preclinical study suggests that the mineralocorticoid receptor, also present in the DRG, may have pro-inflammatory effects that oppose the activation of the glucocorticoid receptor. Although the glucocorticoid receptor is the target of anti-inflammatory steroids, many clinically used steroids activate both receptors. This could be one explanation for the limited effects of epidural steroids in some patients. Additional preclinical research is needed to address other possible reasons for limited efficacy of steroids, such as central sensitization or presence of an ongoing inflammatory stimulus in some forms of low back pain. PMID:23537369

  6. Recommendations for Benchmarking Preclinical Studies of Nanomedicines.

    PubMed

    Dawidczyk, Charlene M; Russell, Luisa M; Searson, Peter C

    2015-10-01

    Nanoparticle-based delivery systems provide new opportunities to overcome the limitations associated with traditional small-molecule drug therapy for cancer and to achieve both therapeutic and diagnostic functions in the same platform. Preclinical trials are generally designed to assess therapeutic potential and not to optimize the design of the delivery platform. Consequently, progress in developing design rules for cancer nanomedicines has been slow, hindering progress in the field. Despite the large number of preclinical trials, several factors restrict comparison and benchmarking of different platforms, including variability in experimental design, reporting of results, and the lack of quantitative data. To solve this problem, we review the variables involved in the design of preclinical trials and propose a protocol for benchmarking that we recommend be included in in vivo preclinical studies of drug-delivery platforms for cancer therapy. This strategy will contribute to building the scientific knowledge base that enables development of design rules and accelerates the translation of new technologies. ©2015 American Association for Cancer Research.

  7. Preclinical Studies for Cartilage Repair

    PubMed Central

    Hurtig, Mark B.; Buschmann, Michael D.; Fortier, Lisa A.; Hoemann, Caroline D.; Hunziker, Ernst B.; Jurvelin, Jukka S.; Mainil-Varlet, Pierre; McIlwraith, C. Wayne; Sah, Robert L.; Whiteside, Robert A.

    2011-01-01

    Investigational devices for articular cartilage repair or replacement are considered to be significant risk devices by regulatory bodies. Therefore animal models are needed to provide proof of efficacy and safety prior to clinical testing. The financial commitment and regulatory steps needed to bring a new technology to clinical use can be major obstacles, so the implementation of highly predictive animal models is a pressing issue. Until recently, a reductionist approach using acute chondral defects in immature laboratory species, particularly the rabbit, was considered adequate; however, if successful and timely translation from animal models to regulatory approval and clinical use is the goal, a step-wise development using laboratory animals for screening and early development work followed by larger species such as the goat, sheep and horse for late development and pivotal studies is recommended. Such animals must have fully organized and mature cartilage. Both acute and chronic chondral defects can be used but the later are more like the lesions found in patients and may be more predictive. Quantitative and qualitative outcome measures such as macroscopic appearance, histology, biochemistry, functional imaging, and biomechanical testing of cartilage, provide reliable data to support investment decisions and subsequent applications to regulatory bodies for clinical trials. No one model or species can be considered ideal for pivotal studies, but the larger animal species are recommended for pivotal studies. Larger species such as the horse, goat and pig also allow arthroscopic delivery, and press-fit or sutured implant fixation in thick cartilage as well as second look arthroscopies and biopsy procedures. PMID:26069576

  8. Quantification of osteolytic bone lesions in a preclinical rat trial

    NASA Astrophysics Data System (ADS)

    Fränzle, Andrea; Bretschi, Maren; Bäuerle, Tobias; Giske, Kristina; Hillengass, Jens; Bendl, Rolf

    2013-10-01

    In breast cancer, most of the patients who died, have developed bone metastasis as disease progression. Bone metastases in case of breast cancer are mainly bone destructive (osteolytic). To understand pathogenesis and to analyse response to different treatments, animal models, in our case rats, are examined. For assessment of treatment response to bone remodelling therapies exact segmentations of osteolytic lesions are needed. Manual segmentations are not only time-consuming but lack in reproducibility. Computerized segmentation tools are essential. In this paper we present an approach for the computerized quantification of osteolytic lesion volumes using a comparison to a healthy reference model. The presented qualitative and quantitative evaluation of the reconstructed bone volumes show, that the automatically segmented lesion volumes complete missing bone in a reasonable way.

  9. Transplantation of Scaffold-Free Cartilage-Like Cell-Sheets Made from Human Bone Marrow Mesenchymal Stem Cells for Cartilage Repair: A Preclinical Study.

    PubMed

    Itokazu, Maki; Wakitani, Shigeyuki; Mera, Hisashi; Tamamura, Yoshihiro; Sato, Yasushi; Takagi, Mutsumi; Nakamura, Hiroaki

    2016-10-01

    The object of this study was to determine culture conditions that create stable scaffold-free cartilage-like cell-sheets from human bone marrow-derived mesenchymal stem cells (hBMSCs) and to assess their effects after transplantation into osteochondral defects in nude rats. (Experiment 1) The hBMSCs were harvested from 3 males, the proliferative and chondrogenic capacities were assessed at passage 1, and the cells were expanded in 3 different culture conditions: (1) 5% fetal bovine serum (FBS), (2) 10% FBS, and (3) 5% FBS with fibroblast growth factor 2 (FGF-2). The cells were harvested and made chondrogenic pellet culture. The cell proliferation rate, glycosaminoglycan/DNA ratio, and safranin-O staining intensity of pellets cultured condition 3 were higher than those of conditions 1 and 2. (Experiment 2) The hBMSCs were expanded and passaged 3 times under culture condition 3, and fabricate the cell-sheets in chondrogenic medium either with or without FBS. The cell-sheets fabricated with FBS maintained their size with flat edges. (Experiment 3) The cell-sheets were transplanted into osteochondral defects in nude rats. Histological analysis was performed at 2, 4, and 12 weeks after surgery. The osteochondral repair was better after sheet transplantation than in the control group and significantly improved Wakitani score. Immunostaining with human-specific vimentin antibody showed that the transplanted cells became fewer and disappeared at 12 weeks. These results indicate that culture with FGF-2 may help to quickly generate sufficient numbers of cells to create stable and reliable scaffold-free cartilage-like cell-sheets, which contribute to the regeneration of osteochondral defects.

  10. Room temperature housing results in premature cancellous bone loss in growing female mice: implications for the mouse as a preclinical model for age-related bone loss.

    PubMed

    Iwaniec, U T; Philbrick, K A; Wong, C P; Gordon, J L; Kahler-Quesada, A M; Olson, D A; Branscum, A J; Sargent, J L; DeMambro, V E; Rosen, C J; Turner, R T

    2016-10-01

    Room temperature housing (22 °C) results in premature cancellous bone loss in female mice. The bone loss was prevented by housing mice at thermoneutral temperature (32 °C). Thermogenesis differs markedly between mice and humans and mild cold stress induced by standard room temperature housing may introduce an unrecognized confounding variable into preclinical studies. Female mice are often used as preclinical models for osteoporosis but, in contrast to humans, mice exhibit cancellous bone loss during growth. Mice are routinely housed at room temperature (18-23 °C), a strategy that exaggerates physiological differences in thermoregulation between mice (obligatory daily heterotherms) and humans (homeotherms). The purpose of this investigation was to assess whether housing female mice at thermoneutral (temperature range where the basal rate of energy production is at equilibrium with heat loss) alters bone growth, turnover and microarchitecture. Growing (4-week-old) female C57BL/6J and C3H/HeJ mice were housed at either 22 or 32 °C for up to 18 weeks. C57BL/6J mice housed at 22 °C experienced a 62 % cancellous bone loss from the distal femur metaphysis during the interval from 8 to 18 weeks of age and lesser bone loss from the distal femur epiphysis, whereas cancellous and cortical bone mass in 32 °C-housed mice were unchanged or increased. The impact of thermoneutral housing on cancellous bone was not limited to C57BL/6J mice as C3H/HeJ mice exhibited a similar skeletal response. The beneficial effects of thermoneutral housing on cancellous bone were associated with decreased Ucp1 gene expression in brown adipose tissue, increased bone marrow adiposity, higher rates of bone formation, higher expression levels of osteogenic genes and locally decreased bone resorption. Housing female mice at 22 °C resulted in premature cancellous bone loss. Failure to account for species differences in thermoregulation may seriously confound interpretation of studies

  11. Anti-RANKL therapy for bone tumours: Basic, pre-clinical and clinical evidences

    PubMed Central

    Heymann, Dominique

    2012-01-01

    Bone remodelling is related to coordinated phases of bone resorption and bone apposition allowing the maintenance of bone integrity, the phosphocalcic homoeostasis all along the life and consequently the bone adaptation to mechanical constraints or/and to endocrine fluctuations. Unfortunately, bone is a frequent site of tumour development originated from bone cell lineages (primary bone tumours: bone sarcomas) or from nonosseous origins (bone metastases: carcinomas). These tumour cells disrupt the balance between osteoblast and osteoclast activities resulting in a disturbed bone remodelling weakening the bone tissue, in a strongly altered bone microenvironment and consequently facilitating the tumour growth. At the early stage of tumour development, osteoclast differentiation and recruitment of mature osteoclasts are strongly activated resulting in a strong bone matrix degradation and release of numerous growth factors initially stored into this organic/calcified matrix. In turn these soluble factors stimulate the proliferation of tumour cells and exacerbate their migration and their ability to initiate metastases. Because Receptor Activator of NFκB Ligand (RANKL) is absolutely required for in vivo osteoclastogenesis, its role in the bone tumour growth has been immediately pointed out and has consequently allowed the development of new targeted therapies of these malignant diseases. The present review summarises the role of RANKL in the bone tumour microenvironment, the most recent pre-clinical and clinical evidences of its targeting in bone metastases and bone sarcomas. The following sections position RANKL targeted therapy among the other anti-resorptive therapies available and underline the future directions which are currently under investigations. PMID:26909248

  12. Oncolysis by paramyxoviruses: preclinical and clinical studies

    PubMed Central

    Matveeva, Olga V; Guo, Zong S; Senin, Vyacheslav M; Senina, Anna V; Shabalina, Svetlana A; Chumakov, Peter M

    2015-01-01

    Preclinical studies demonstrate that a broad spectrum of human malignant cells can be killed by oncolytic paramyxoviruses, which include cells of ecto-, endo-, and mesodermal origin. In clinical trials, significant reduction in size or even complete elimination of primary tumors and established metastases are reported. Different routes of viral administration (intratumoral, intravenous, intradermal, intraperitoneal, or intrapleural), and single- versus multiple-dose administration schemes have been explored. The reported side effects are grade 1 and 2, with the most common among them being mild fever. Some advantages in using paramyxoviruses as oncolytic agents versus representatives of other viral families exist. The cytoplasmic replication results in a lack of host genome integration and recombination, which makes paramyxoviruses safer and more attractive candidates for widely used therapeutic oncolysis in comparison with retroviruses or some DNA viruses. The list of oncolytic paramyxovirus representatives includes attenuated measles virus (MV), mumps virus (MuV), low pathogenic Newcastle disease (NDV), and Sendai (SeV) viruses. Metastatic cancer cells frequently overexpress on their surface some molecules that can serve as receptors for MV, MuV, NDV, and SeV. This promotes specific viral attachment to the malignant cell, which is frequently followed by specific viral replication. The paramyxoviruses are capable of inducing efficient syncytium-mediated lyses of cancer cells and elicit strong immunomodulatory effects that dramatically enforce anticancer immune surveillance. In general, preclinical studies and phase 1–3 clinical trials yield very encouraging results and warrant continued research of oncolytic paramyxoviruses as a particularly valuable addition to the existing panel of cancer-fighting approaches. PMID:26640815

  13. Preclinical studies of alcohol binge drinking

    PubMed Central

    Crabbe, John C.; Harris, R. Adron; Koob, George F.

    2011-01-01

    Binge drinking is prevalent and has serious biomedical consequences. In children, adolescents, and young adults, it is a prominent risk factor for later development of alcohol-use disorders. Many preclinical models have been employed to study the genetic risks for and biomedical consequences of alcohol drinking. However, these models historically did not result in blood-alcohol concentrations (BACs) exceding 80 mg%; this relatively modest level is the threshold that currently defines a binge session, according to the NIAAA and CDC. Nevertheless, in alcohol-dependent rodents, binge drinking has been well documented. Key neurobiological substrates localized to brain reward and stress systems have been identified. Studies of newer models of binge drinking without dependence are reviewed here. In these models, rodents, non-human primates, and flies will drink enough to reach high BACs. They often display observable signs of intoxication. The neurobiological consequences of these episodes of binge drinking without dependence are reviewed, preliminary evidence for roles for GABA, glutamate, opioid peptides, and corticotropin releasing factor are discussed, as is the need for more work to identify the antecedents and consequences of binge drinking in both animal models and humans. PMID:21272009

  14. Novel Bone-Anchored Vascular Access on the Mastoid for Hemodialysis: Concept and Preclinical Trials.

    PubMed

    Stieger, Christof; Arnold, Andreas; Kruse, Anja; Wiedmer, Simona; Widmer, Matthias; Guignard, Jeremie; Schutz, Daniel; Guenat, Jean-Marc; Bachtler, Matthias; Caversaccio, Marco; Uehlinger, Dominik E; Frey, Felix J; Hausler, Rudolf

    2016-05-01

    We present the development of a bone-anchored port for the painless long-term hemodialytic treatment of patients with renal failure. This port is implanted behind the ear. The port was developed based on knowledge obtained from long-term experience with implantable hearing devices, which are firmly anchored to the bone behind the ear. This concept of bone anchoring was adapted to the requirements for a vascular access during hemodialysis. The investigational device is comprised of a base plate that is firmly fixed with bone screws to the bone behind the ear (temporal bone). A catheter leads from the base plate valve block through the internal jugular vein and into the right atrium. The valves are opened using a special disposable adapter, without any need to puncture the blood vessels. Between hemodialysis sessions, the port is protected with a disposable cover. Flow rate, leak tightness, and purification were tested on mockups. Preoperative planning and the surgical procedure were verified in 15 anatomical human whole head specimens. Preclinical evaluations demonstrated the technical feasibility and safety of the investigational device. Approximately 1.5 million people are treated with hemodialysis worldwide, and 25% of the overall cost of dialysis therapy results from vascular access problems. New approaches toward enhancing vascular access could potentially reduce the costs and complications of hemodialytic therapy.

  15. Delayed minimally invasive injection of allogenic bone marrow stromal cell sheets regenerates large bone defects in an ovine preclinical animal model.

    PubMed

    Berner, Arne; Henkel, Jan; Woodruff, Maria A; Steck, Roland; Nerlich, Michael; Schuetz, Michael A; Hutmacher, Dietmar W

    2015-05-01

    Cell-based tissue engineering approaches are promising strategies in the field of regenerative medicine. However, the mode of cell delivery is still a concern and needs to be significantly improved. Scaffolds and/or matrices loaded with cells are often transplanted into a bone defect immediately after the defect has been created. At this point, the nutrient and oxygen supply is low and the inflammatory cascade is incited, thus creating a highly unfavorable microenvironment for transplanted cells to survive and participate in the regeneration process. We therefore developed a unique treatment concept using the delayed injection of allogenic bone marrow stromal cell (BMSC) sheets to regenerate a critical-sized tibial defect in sheep to study the effect of the cells' regeneration potential when introduced at a postinflammatory stage. Minimally invasive percutaneous injection of allogenic BMSCs into biodegradable composite scaffolds 4 weeks after the defect surgery led to significantly improved bone regeneration compared with preseeded scaffold/cell constructs and scaffold-only groups. Biomechanical testing and microcomputed tomography showed comparable results to the clinical reference standard (i.e., an autologous bone graft). To our knowledge, we are the first to show in a validated preclinical large animal model that delayed allogenic cell transplantation can provide applicable clinical treatment alternatives for challenging bone defects in the future.

  16. [Preclinical data as basis for the design of clinical studies].

    PubMed

    Fichtner, Iduna

    2008-01-01

    The preclinical development of novel anticancer compounds mainly resembles the same principle as valid for other drug classes. New target structures on tumors are identified within academic or industrial fundamental research groups enabling a selective attack of cancerostatics. After the proof of principle in molecular or cellular systems, substance candidates are selected which undergo a stepwise preclinical testing. This procedure consists of cell culture models (in vitro) and animal experiments (in vivo) using suitable tumor models. With selected lead compounds the pharmaceutical formulation is prepared, and the legally required preclinical toxicological investigations are performed before initiation of clinical phase I studies. There is one special feature distinguishing cytostatics from all other drugs - their narrow therapeutic index. This constraint is to be considered already in early phases of anticancer drug development, and a special focus should be given to the revealing of potential side effects. This contribution especially gives attention to this aspect of preclinical anticancer drug development. Further on, focus is put on target-oriented compounds, whose preclinical development generates special challenges. Copyright 2008 S. Karger AG, Basel.

  17. Analgesia in Amphibians: Preclinical Studies and Clinical Applications

    PubMed Central

    Stevens, Craig W.

    2010-01-01

    SYNOPSIS Preclinical studies of analgesia in amphibians or recommendations for clinical use of analgesics in amphibian species are extremely limited. This article briefly reviews the issues surrounding the use of analgesics in amphibians starting with common definitions of pain and analgesia when applied to non-human animals. Nociceptive and endogenous opioid systems in amphibians are reviewed and results of preclinical research on opioid and non-opioid analgesics summarized. Recommended opioid and non-opioid analgesics are summarized and practical recommendations made for their clinical use. PMID:21074701

  18. Database setup for preclinical studies of gene-modified hematopoiesis.

    PubMed

    Balcik, Brenden; Grassman, Elke; Reeves, Lilith

    2009-01-01

    Murine safety studies are routinely used for gathering preclinical safety and efficacy data and, for Phase I studies, Good Laboratory Practice (GLP) compliance is not mandated. However, extensive amounts of data must be gathered and analyzed. An inter-relational database is an effective tool for storing, sorting, and reviewing data.

  19. Bridging Translation by Improving Preclinical Study Design in AKI.

    PubMed

    de Caestecker, Mark; Humphreys, Ben D; Liu, Kathleen D; Fissell, William H; Cerda, Jorge; Nolin, Thomas D; Askenazi, David; Mour, Girish; Harrell, Frank E; Pullen, Nick; Okusa, Mark D; Faubel, Sarah

    2015-12-01

    Despite extensive research, no therapeutic interventions have been shown to prevent AKI, accelerate recovery of AKI, or reduce progression of AKI to CKD in patients. This failure in translation has led investigators to speculate that the animal models being used do not predict therapeutic responses in humans. Although this issue continues to be debated, an important concern that has not been addressed is whether improvements in preclinical study design can be identified that might also increase the likelihood of translating basic AKI research into clinical practice using the current models. In this review, we have taken an evidence-based approach to identify common weaknesses in study design and reporting in preclinical AKI research that may contribute to the poor translatability of the findings. We focused on use of N-acetylcysteine or sodium bicarbonate for the prevention of contrast-induced AKI and use of erythropoietin for the prevention of AKI, two therapeutic approaches that have been extensively studied in clinical trials. On the basis of our findings, we identified five areas for improvement in preclinical study design and reporting. These suggested and preliminary guidelines may help improve the quality of preclinical research for AKI drug development.

  20. Bridging Translation by Improving Preclinical Study Design in AKI

    PubMed Central

    Humphreys, Ben D.; Liu, Kathleen D.; Fissell, William H.; Cerda, Jorge; Nolin, Thomas D.; Askenazi, David; Mour, Girish; Harrell, Frank E.; Pullen, Nick; Okusa, Mark D.

    2015-01-01

    Despite extensive research, no therapeutic interventions have been shown to prevent AKI, accelerate recovery of AKI, or reduce progression of AKI to CKD in patients. This failure in translation has led investigators to speculate that the animal models being used do not predict therapeutic responses in humans. Although this issue continues to be debated, an important concern that has not been addressed is whether improvements in preclinical study design can be identified that might also increase the likelihood of translating basic AKI research into clinical practice using the current models. In this review, we have taken an evidence-based approach to identify common weaknesses in study design and reporting in preclinical AKI research that may contribute to the poor translatability of the findings. We focused on use of N-acetylcysteine or sodium bicarbonate for the prevention of contrast-induced AKI and use of erythropoietin for the prevention of AKI, two therapeutic approaches that have been extensively studied in clinical trials. On the basis of our findings, we identified five areas for improvement in preclinical study design and reporting. These suggested and preliminary guidelines may help improve the quality of preclinical research for AKI drug development. PMID:26538634

  1. USHERING IN THE STUDY AND TREATMENT OF PRECLINICAL ALZHEIMER DISEASE

    PubMed Central

    Langbaum, Jessica B.S.; Fleisher, Adam S.; Chen, Kewei; Ayutyanont, Napatkamon; Lopera, Francisco; Quiroz, Yakeel T.; Caselli, Richard J.; Tariot, Pierre N.; Reiman, Eric M.

    2014-01-01

    Researchers have begun to characterize the subtle biological and cognitive processes that precede the clinical onset of Alzheimer disease (AD), and to set the stage for accelerated evaluation of experimental treatments to delay the onset, reduce the risk of or completely prevent clinical decline. Here, we provide an overview of the experimental strategies, and brain imaging and cerebrospinal fluid biomarker measures that are used in early detection and tracking of AD, highlighting at-risk individuals who could be suitable for preclinical monitoring. We discuss how these advances have contributed to reconceptualization of AD as a sequence of biological changes that occur during progression from preclinical AD, to mild cognitive impairment and finally dementia, and we review recently proposed research criteria for preclinical AD. Advances in the study of preclinical AD have driven the recognition that efficacy of at least some AD therapies may depend on initiation of treatment before clinical manifestation of disease, leading to a new era of AD prevention research. PMID:23752908

  2. Ushering in the study and treatment of preclinical Alzheimer disease.

    PubMed

    Langbaum, Jessica B; Fleisher, Adam S; Chen, Kewei; Ayutyanont, Napatkamon; Lopera, Francisco; Quiroz, Yakeel T; Caselli, Richard J; Tariot, Pierre N; Reiman, Eric M

    2013-07-01

    Researchers have begun to characterize the subtle biological and cognitive processes that precede the clinical onset of Alzheimer disease (AD), and to set the stage for accelerated evaluation of experimental treatments to delay the onset, reduce the risk of, or completely prevent clinical decline. In this Review, we provide an overview of the experimental strategies, and brain imaging and cerebrospinal fluid biomarker measures that are used in early detection and tracking of AD, highlighting at-risk individuals who could be suitable for preclinical monitoring. We discuss how advances in the field have contributed to reconceptualization of AD as a sequence of biological changes that occur during progression from preclinical AD, to mild cognitive impairment and finally dementia, and we review recently proposed research criteria for preclinical AD. Advances in the study of preclinical AD have driven the recognition that efficacy of at least some AD therapies may depend on initiation of treatment before clinical manifestation of disease, leading to a new era of AD prevention research.

  3. Perspective: Recommendations for benchmarking pre-clinical studies of nanomedicines

    PubMed Central

    Dawidczyk, Charlene M.; Russell, Luisa M.; Searson, Peter C.

    2015-01-01

    Nanoparticle-based delivery systems provide new opportunities to overcome the limitations associated with traditional small molecule drug therapy for cancer, and to achieve both therapeutic and diagnostic functions in the same platform. Pre-clinical trials are generally designed to assess therapeutic potential and not to optimize the design of the delivery platform. Consequently, progress in developing design rules for cancer nanomedicines has been slow, hindering progress in the field. Despite the large number of pre-clinical trials, several factors restrict comparison and benchmarking of different platforms, including variability in experimental design, reporting of results, and the lack of quantitative data. To solve this problem, we review the variables involved in the design of pre-clinical trials and propose a protocol for benchmarking that we recommend be included in in vivo pre-clinical studies of drug delivery platforms for cancer therapy. This strategy will contribute to building the scientific knowledge base that enables development of design rules and accelerates the translation of new technologies. PMID:26249177

  4. Preclinical Trauma Studies of Recombinant Factor VIIa

    DTIC Science & Technology

    2005-10-07

    NovoSeven®) in treating thrombocytopenic rabbits and for the reversal of anticoagulation. Safety models in the rabbit also exist to test for systemic...thromboplastin. These considerations are compounded by the fact that the majority of standard in vitro coagulation assays are performed with rabbit brain...or brain in the treated groups. The final animal study described in this review was designed by Sondeen and coworkers [18] to test the efficacy of

  5. Eribulin—A review of preclinical and clinical studies

    PubMed Central

    Swami, Umang; Chaudhary, Imran; Ghalib, Mohammad H.; Goel, Sanjay

    2013-01-01

    Eribulin mesylate is a non-taxane, structurally simplified, completely synthetic, halichondrin B derivative with an end poisoning, microtubule inhibitory action. Preclinical studies have demonstrated activity in various cancer cell lines and synergistic action with gemcitabine, epirubicin, trastuzumab, cisplatin, docetaxel and vinorelbine. Eribulin has recently been approved by United States Food and Drug Administration as a third line therapy for metastatic breast cancer patients, who have previously been treated with an anthracycline and a taxane. It has also advanced to phase II trials in non-small cell lung cancer, pancreatic, prostate, bladder, head and neck cancers, sarcomas and ovarian and other gynecological tumors. Combination trials with carboplatin, gemcitabine, pemetrexed, cisplatin, and erlotinib are currently ongoing. Eribulin potentially has a low incidence of peripheral neuropathy. The predominant side effects are neutropenia and fatigue, which are manageable. This article reviews the available information on eribulin with respect to its clinical pharmacology, mechanism of action, pharmacokinetics, pharmacodynamics, metabolism, preclinical studies and clinical trials. PMID:21493087

  6. Genetically Engineered Humanized Mouse Models for Preclinical Antibody Studies

    PubMed Central

    Proetzel, Gabriele; Wiles, Michael V.; Roopenian, Derry C.

    2015-01-01

    The use of genetic engineering has vastly improved our capabilities to create animal models relevant in preclinical research. With the recent advances in gene-editing technologies, it is now possible to very rapidly create highly tunable mouse models as needs arise. Here, we provide an overview of genetic engineering methods, as well as the development of humanized neonatal Fc receptor (FcRn) models and their use for monoclonal antibody in vivo studies. PMID:24150980

  7. [Latrepirdine: a systematic review of the preclinical studies].

    PubMed

    Cano-Cuenca, Nieves; Solís-García del Pozo, Julián; Jordán, Joaquín

    2015-01-01

    We conduct a systematic review of the preclinical studies published to date involving the use of latrepirdine (Dimebon ®). Latrepirdine is capable of modulating different targets, such as those related with mitochondria, acetylcholinesterase activity or intraneuronal calcium levels, perhaps thanks to its action upon the N-methyl-D-aspartate-type receptor, which belongs to the glutamate family. The findings published on the possible effect of latrepirdine in protein aggregation processes in disorders such as Alzheimer's disease and Parkinson's disease are quite controversial. Likewise, the possible neuroprotective effect of latrepirdine has been evaluated in animal models of neurodegenerative diseases, again with heterogeneous results. Consequently, it can be concluded that no preclinical scientific evidence has been found to justify carrying out clinical trials.

  8. Preclinical models for in vitro mechanical loading of bone-derived cells.

    PubMed

    Michael Delaine-Smith, Robin; Javaheri, Behzad; Helen Edwards, Jennifer; Vazquez, Marisol; Rumney, Robin Mark Howard

    2015-01-01

    It is well established that bone responds to mechanical stimuli whereby physical forces are translated into chemical signals between cells, via mechanotransduction. It is difficult however to study the precise cellular and molecular responses using in vivo systems. In vitro loading models, which aim to replicate forces found within the bone microenvironment, make the underlying processes of mechanotransduction accessible to the researcher. Direct measurements in vivo and predictive modeling have been used to define these forces in normal physiological and pathological states. The types of mechanical stimuli present in the bone include vibration, fluid shear, substrate deformation and compressive loading, which can all be applied in vitro to monolayer and three-dimensional (3D) cultures. In monolayer, vibration can be readily applied to cultures via a low-magnitude, high-frequency loading rig. Fluid shear can be applied to cultures in multiwell plates via a simple rocking platform to engender gravitational fluid movement or via a pump to cells attached to a slide within a parallel-plate flow chamber, which may be micropatterned for use with osteocytes. Substrate strain can be applied via the vacuum-driven FlexCell system or via a four-point loading jig. 3D cultures better replicate the bone microenvironment and can also be subjected to the same forms of mechanical stimuli as monolayer, including vibration, fluid shear via perfusion flow, strain or compression. 3D cocultures that more closely replicate the bone microenvironment can be used to study the collective response of several cell types to loading. This technical review summarizes the methods for applying mechanical stimuli to bone cells in vitro.

  9. Preclinical models for in vitro mechanical loading of bone-derived cells

    PubMed Central

    Michael Delaine-Smith, Robin; Javaheri, Behzad; Helen Edwards, Jennifer; Vazquez, Marisol; Rumney, Robin Mark Howard

    2015-01-01

    It is well established that bone responds to mechanical stimuli whereby physical forces are translated into chemical signals between cells, via mechanotransduction. It is difficult however to study the precise cellular and molecular responses using in vivo systems. In vitro loading models, which aim to replicate forces found within the bone microenvironment, make the underlying processes of mechanotransduction accessible to the researcher. Direct measurements in vivo and predictive modeling have been used to define these forces in normal physiological and pathological states. The types of mechanical stimuli present in the bone include vibration, fluid shear, substrate deformation and compressive loading, which can all be applied in vitro to monolayer and three-dimensional (3D) cultures. In monolayer, vibration can be readily applied to cultures via a low-magnitude, high-frequency loading rig. Fluid shear can be applied to cultures in multiwell plates via a simple rocking platform to engender gravitational fluid movement or via a pump to cells attached to a slide within a parallel-plate flow chamber, which may be micropatterned for use with osteocytes. Substrate strain can be applied via the vacuum-driven FlexCell system or via a four-point loading jig. 3D cultures better replicate the bone microenvironment and can also be subjected to the same forms of mechanical stimuli as monolayer, including vibration, fluid shear via perfusion flow, strain or compression. 3D cocultures that more closely replicate the bone microenvironment can be used to study the collective response of several cell types to loading. This technical review summarizes the methods for applying mechanical stimuli to bone cells in vitro. PMID:26331007

  10. Preclinical models in the study of sex differences.

    PubMed

    Buoncervello, Maria; Marconi, Matteo; Carè, Alessandra; Piscopo, Paola; Malorni, Walter; Matarrese, Paola

    2017-03-01

    The biology of sex differences deals with the study of the disparities between females and males and the related biological mechanisms. Gender medicine focuses on the impact of gender and sex on human physiology, pathophysiology and clinical features of diseases that are common to women and men. The term gender refers to a complex interrelation and integration of sex-as a biological and functional determinant-and psychological and cultural behaviours (due to ethnical, social or religious background). The attention to the impact of gender differences on the pathophysiology and, therefore, on the clinical management of the most common diseases, such as cardiovascular diseases (CVD), neurodegenerative disorders, immune and autoimmune diseases as well as several tumours, is in fact often neglected. Hence, studies covering different fields of investigation and including sex differences in the pathogenesis, in diagnostic and prognostic criteria as well as in response to therapy appear mandatory. However, prerequisites for this development are preclinical studies, including in vitro and in vivo approaches. They represent the first step in the development of a drug or in the comprehension of the pathogenetic mechanisms of diseases, in turn a necessary step for the development of new or more appropriate therapeutic strategies. However, sex differences are still poorly considered and the great majority of preclinical studies do not take into account the relevance of such disparities. In this review, we describe the state of the art of these studies and provide some paradigmatic examples of key fields of investigation, such as oncology, neurology and CVD, where preclinical models should be improved.

  11. Preclinical Studies and Translational Applications of Intracerebral Hemorrhage

    PubMed Central

    Nyanzu, Mark; Ni, Haoqi; Lin, Xiao; Xu, Zhu; Ruan, Linhui

    2017-01-01

    Intracerebral hemorrhage (ICH) which refers to bleeding in the brain is a very deleterious condition with high mortality and disability rate. Surgery or conservative therapy remains the treatment option. Various studies have divided the disease process of ICH into primary and secondary injury, for which knowledge into these processes has yielded many preclinical and clinical treatment options. The aim of this review is to highlight some of the new experimental drugs as well as other treatment options like stem cell therapy, rehabilitation, and nanomedicine and mention some translational clinical applications that have been done with these treatment options. PMID:28698874

  12. Optimized design and analysis of preclinical intervention studies in vivo

    PubMed Central

    Laajala, Teemu D.; Jumppanen, Mikael; Huhtaniemi, Riikka; Fey, Vidal; Kaur, Amanpreet; Knuuttila, Matias; Aho, Eija; Oksala, Riikka; Westermarck, Jukka; Mäkelä, Sari; Poutanen, Matti; Aittokallio, Tero

    2016-01-01

    Recent reports have called into question the reproducibility, validity and translatability of the preclinical animal studies due to limitations in their experimental design and statistical analysis. To this end, we implemented a matching-based modelling approach for optimal intervention group allocation, randomization and power calculations, which takes full account of the complex animal characteristics at baseline prior to interventions. In prostate cancer xenograft studies, the method effectively normalized the confounding baseline variability, and resulted in animal allocations which were supported by RNA-seq profiling of the individual tumours. The matching information increased the statistical power to detect true treatment effects at smaller sample sizes in two castration-resistant prostate cancer models, thereby leading to saving of both animal lives and research costs. The novel modelling approach and its open-source and web-based software implementations enable the researchers to conduct adequately-powered and fully-blinded preclinical intervention studies, with the aim to accelerate the discovery of new therapeutic interventions. PMID:27480578

  13. APP mouse models for Alzheimer's disease preclinical studies.

    PubMed

    Sasaguri, Hiroki; Nilsson, Per; Hashimoto, Shoko; Nagata, Kenichi; Saito, Takashi; De Strooper, Bart; Hardy, John; Vassar, Robert; Winblad, Bengt; Saido, Takaomi C

    2017-09-01

    Animal models of human diseases that accurately recapitulate clinical pathology are indispensable for understanding molecular mechanisms and advancing preclinical studies. The Alzheimer's disease (AD) research community has historically used first-generation transgenic (Tg) mouse models that overexpress proteins linked to familial AD (FAD), mutant amyloid precursor protein (APP), or APP and presenilin (PS). These mice exhibit AD pathology, but the overexpression paradigm may cause additional phenotypes unrelated to AD Second-generation mouse models contain humanized sequences and clinical mutations in the endogenous mouse App gene. These mice show Aβ accumulation without phenotypes related to overexpression but are not yet a clinical recapitulation of human AD In this review, we evaluate different APP mouse models of AD, and review recent studies using the second-generation mice. We advise AD researchers to consider the comparative strengths and limitations of each model against the scientific and therapeutic goal of a prospective preclinical study. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  14. [The preclinical efficacy of emergency care. A prospective study].

    PubMed

    Hennes, H J; Reinhardt, T; Otto, S; Dick, W

    1993-07-01

    Quality assurance has become an important issue in emergency medicine. At present, no prospective studies are available that quantify the efficacy of interventions performed by emergency doctors. The development and implementation of a rapid, yet simple scoring system, allowing preclinical assessment of all emergency medicine patients, is required. Once the scoring system is implemented, evaluation of the prehospital intervention, based upon objective parameters, is possible. METHODS. The Mainz Emergency Evaluation Score (MEES) is based on seven parameters: level of consciousness, heart rate, heart rhythm, arterial blood pressure, respiratory rate, partial arterial oxygen saturation and pain. A coded value is assigned to each parameter, with the normal physiological condition securing a score of 4, while a life-threatening condition receives a value of 1. For the parameter of pain there is no life-threatening condition, so the lowest value allowed is 2 (Table 2). Addition of the respective values from the seven parameters yields the MEES value, which objectively reflects the patients' condition (minimum = 8, maximum = 28). Comparing the MEES value before (MEES1) and after the intervention (MEES2) allows an objective evaluation of the efficacy of the preclinical care (delta-MEES = MEES2-MEES1). A difference of > or = +2 is considered an improvement, +1, +/- 0, -1 are rated as unchanged and < or = -2 is considered a deterioration in the patients condition. For more detailed evaluation the patients were allocated to 16 diagnosis groups (Table 3). Statistical evaluation utilized analysis of variance, the rank sum test (Wilcoxon) and the correlation coefficient (Kendall-Tau). RESULTS. In 356 patients the condition of 187 (52%) patients improved during the preclinical treatment; the condition of 156 (44%) patients did not change. In 13 patients (3%) the condition became worse (Table 5, Fig. 2). Allocation to 16 diagnosis groups revealed that the improvement in the

  15. Preclinical Evaluation of Zoledronate to Maintain Bone Allograft and Improve Implant Fixation in Revision Joint Replacement

    PubMed Central

    Sørensen, Mette; Barckman, Jeppe; Bechtold, Joan E.; Søballe, Kjeld; Baas, Jørgen

    2013-01-01

    Background: Revision arthroplasty surgery is often complicated by loss of bone stock that can be managed by the use of bone allograft. The allograft provides immediate stability for the revision implant but may be resorbed, impairing subsequent implant stability. Bisphosphonates can delay allograft resorption. We hypothesized that zoledronate-impregnated allograft impacted around revision implants would improve implant fixation as characterized by mechanical push-out testing and histomorphometry. Methods: Twenty-four axially pistoning micromotion devices were inserted bilaterally into the knees of twelve dogs according to our revision protocol. This produced a standardized revision cavity with a loose implant, fibrous tissue, and a sclerotic bone rim. Revision surgery was performed eight weeks later; after stable titanium revision components were implanted, saline solution-soaked allograft was impacted around the component on the control side and allograft soaked in 0.005 mg/mL zoledronate was impacted on the intervention side. The results were evaluated after four weeks. Results: The zoledronate treatment resulted in a 30% increase in ultimate shear strength (p = 0.023), a 54% increase in apparent shear stiffness (p = 0.002), and a 12% increase in total energy absorption (p = 0.444). The quantity of allograft in the gap was three times greater in the zoledronate group compared with the control group (p < 0.001). The volume fraction of new bone in the zoledronate group (25%; 95% confidence interval [CI], 22% to 28%) was similar to that in the control group (23%; 95% CI, 19% to 26%) (p = 0.311). Conclusions: The data obtained in this canine model suggest that pretreating allograft with zoledronate may be beneficial for early stability of grafted revision arthroplasty implants, without any adverse effect on bone formation. Clinical studies are warranted. Clinical Relevance: The zoledronate treatment is simple to apply in the clinical setting. The treatment could

  16. Oral immunotherapy for food allergy: clinical and preclinical studies.

    PubMed

    Kulis, Mike; Wesley Burks, A

    2013-06-15

    Food allergies affect approximately 5% of the U.S. population and have increased in the last decade. In recent years, oral immunotherapy (OIT) has been tested in clinical trials for peanut, milk, and egg allergies in young children. OIT appears to be fairly well tolerated by most subjects and leads to desensitization with a greatly increased threshold of allergen required to induce reactions. Further approaches being investigated in preclinical studies in mouse models indicate the potential for using adjuvants, such as TLR9 agonists in combination with OIT; peptide OIT; and non-allergen specific applications such as herbal formulations. Further questions about OIT remain, including the optimal dosing and length of treatment; whether tolerance can be developed; and the exact cellular mechanisms resulting in protection following OIT. With many clinical trials underway across the United States and other countries, and a growing pipeline of preclinical research with translational potential, there is great hope for a widely applicable food allergy treatment. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Using Micro-CT Derived Bone Microarchitecture to Analyze Bone Stiffness – A Case Study on Osteoporosis Rat Bone

    PubMed Central

    Wu, Yuchin; Adeeb, Samer; Doschak, Michael R.

    2015-01-01

    Micro-computed tomography (Micro-CT) images can be used to quantitatively represent bone geometry through a range of computed attenuation-based parameters. Nonetheless, those parameters remain indirect indices of bone microarchitectural strength and require further computational tools to interpret bone structural stiffness and potential for mechanical failure. Finite element analysis (FEA) can be applied to measure trabecular bone stiffness and potentially predict the location of structural failure in preclinical animal models of osteoporosis, although that procedure from image segmentation of Micro-CT derived bone geometry to FEA is often challenging and computationally expensive, resulting in failure of the model to build. Notably, the selection of resolution and threshold for bone segmentation are key steps that greatly affect computational complexity and validity. In the following study, we evaluated an approach whereby Micro-CT derived grayscale attenuation and segmentation data guided the selection of trabecular bone for analysis by FEA. We further correlated those FEA results to both two- and three-dimensional bone microarchitecture from sham and ovariectomized (OVX) rats (n = 10/group). A virtual cylinder of vertebral trabecular bone 40% in length from the caudal side was selected for FEA, because Micro-CT based image analysis indicated the largest differences in microarchitecture between the two groups resided there. Bone stiffness was calculated using FEA and statistically correlated with the three-dimensional values of bone volume/tissue volume, bone mineral density, fractal dimension, trabecular separation, and trabecular bone pattern factor. Our method simplified the process for the assessment of trabecular bone stiffness by FEA from Micro-CT images and highlighted the importance of bone microarchitecture in conferring significantly increased bone quality capable of resisting failure due to increased mechanical loading. PMID:26042089

  18. Preliminary study for small animal preclinical hadrontherapy facility

    NASA Astrophysics Data System (ADS)

    Russo, G.; Pisciotta, P.; Cirrone, G. A. P.; Romano, F.; Cammarata, F.; Marchese, V.; Forte, G. I.; Lamia, D.; Minafra, L.; Bravatá, V.; Acquaviva, R.; Gilardi, M. C.; Cuttone, G.

    2017-02-01

    Aim of this work is the study of the preliminary steps to perform a particle treatment of cancer cells inoculated in small animals and to realize a preclinical hadrontherapy facility. A well-defined dosimetric protocol was developed to explicate the steps needed in order to perform a precise proton irradiation in small animals and achieve a highly conformal dose into the target. A precise homemade positioning and holding system for small animals was designed and developed at INFN-LNS in Catania (Italy), where an accurate Monte Carlo simulation was developed, using Geant4 code to simulate the treatment in order to choose the best animal position and perform accurately all the necessary dosimetric evaluations. The Geant4 application can also be used to realize dosimetric studies and its peculiarity consists in the possibility to introduce the real target composition in the simulation using the DICOM micro-CT image. This application was fully validated comparing the results with the experimental measurements. The latter ones were performed at the CATANA (Centro di AdroTerapia e Applicazioni Nucleari Avanzate) facility at INFN-LNS by irradiating both PMMA and water solid phantom. Dosimetric measurements were performed using previously calibrated EBT3 Gafchromic films as a detector and the results were compared with the Geant4 simulation ones. In particular, two different types of dosimetric studies were performed: the first one involved irradiation of a phantom made up of water solid slabs where a layer of EBT3 was alternated with two different slabs in a sandwich configuration, in order to validate the dosimetric distribution. The second one involved irradiation of a PMMA phantom made up of a half hemisphere and some PMMA slabs in order to simulate a subcutaneous tumour configuration, normally used in preclinical studies. In order to evaluate the accordance between experimental and simulation results, two different statistical tests were made: Kolmogorov test and

  19. Resveratrol: A review of preclinical studies for human cancer prevention

    SciTech Connect

    Athar, Mohammad; Back, Jung Ho; Tang Xiuwei; Kim, Kwang Ho; Kopelovich, Levy; Bickers, David R.; Kim, Arianna L.

    2007-11-01

    The search for novel and effective cancer chemopreventive agents has led to the identification of various naturally occurring compounds one of which is resveratrol (trans-3,4',5-trihydroxystilbene), a phytoalexin derived from the skin of grapes and other fruits. Resveratrol is known to have potent anti-inflammatory and antioxidant effects and to inhibit platelet aggregation and the growth of a variety of cancer cells. Its potential chemopreventive and chemotherapeutic activities have been demonstrated in all three stages of carcinogenesis (initiation, promotion, and progression), in both chemically and UVB-induced skin carcinogenesis in mice, as well as in various murine models of human cancers. Evidence from numerous in vitro and in vivo studies has confirmed its ability to modulate various targets and signaling pathways. This review discusses the current preclinical and mechanistic data available and assesses resveratrol's anticancer effects to support its potential as an anticancer agent in human populations.

  20. Preclinical studies for gene therapy of Duchenne muscular dystrophy.

    PubMed

    Odom, Guy L; Banks, Glen B; Schultz, Brian R; Gregorevic, Paul; Chamberlain, Jeffrey S

    2010-09-01

    The muscular dystrophies are a diverse group of genetic disorders without an effective treatment. Because they are caused by mutations in various genes, the most direct way to treat them involves correcting the underlying gene defect (ie, gene therapy). Such a gene therapy approach involves delivering a therapeutic gene cassette to essentially all the muscles of the body in a safe and efficacious manner. The authors describe gene delivery methods using vectors derived from adeno-associated virus that are showing great promise in preclinical studies for treatment of Duchenne muscular dystrophy. It is hoped that variations on these methods might be applicable for most, if not all, of the different types of muscular dystrophy.

  1. A targeted approach for evaluating preclinical activity of botanical extracts for support of bone health.

    PubMed

    Lin, Yumei; Murray, Mary A; Garrett, I Ross; Gutierrez, Gloria E; Nyman, Jeffry S; Mundy, Gregory; Fast, David; Gellenbeck, Kevin W; Chandra, Amitabh; Ramakrishnan, Shyam

    2014-01-01

    Using a sequential in vitro/in vivo approach, we tested the ability of botanical extracts to influence biomarkers associated with bone resorption and bone formation. Pomegranate fruit and grape seed extracts were found to exhibit anti-resorptive activity by inhibiting receptor activator of nuclear factor-κB ligand (RANKL) expression in MG-63 cells and to reduce IL-1β-stimulated calvarial (45)Ca loss. A combination of pomegranate fruit and grape seed extracts were shown to be effective at inhibiting bone loss in ovariectomised rats as demonstrated by standard histomorphometry, biomechanical and bone mineral density measurements. Quercetin and licorice extract exhibited bone formation activity as measured by bone morphogenetic protein-2 (BMP-2) promoter activation, increased expression of BMP-2 mRNA and protein levels, and promotion of bone growth in cultured mouse calvariae. A combination of quercetin and licorice extract demonstrated a potential for increasing bone mineral density in an intact female rat model as compared with controls. The results from this sequential in vitro/in vivo research model yielded botanical extract formulas that demonstrate significant potential benefits for bone health.

  2. Feasibility study of pre-clinical Thiel embalmed human cadaver for MR-guided focused ultrasound of the spine.

    PubMed

    Karakitsios, Ioannis; Mihcin, Senay; Saliev, Timur; Melzer, Andreas

    2016-01-01

    Magnetic Resonance-guided Focused Ultrasound Surgery (MRgFUS) is a non-invasive treatment option based on high acoustic absorption and minimal thermal conductivity of the bone to destroy nerves and reduce pain. There is lack of a preclinical validation tool with correct human anatomy. This work introduces usage of an ex-vivo Thiel embalmed human tissue model for preclinical verification of MRgFUS on intervertebral discs or bone metastases within the spinal body. Thiel embalmed human cadaver was subjected to FUS sonication of the vertebra (with energies 250J, 420J, 600J) and the intervertebral disc (with energies 310J, 610J, 950J) of the lumbar spine for 20s of sonication under MR guidance. For the vertebra, maximum temperatures were recorded as 38 °C, 58.3 °C, 69 °C. The intervertebral disc reached maximum temperatures of 23.7 °C, 54 °C, 83 °C. The temperature measurements showed that the spinal canal and adjacent organs were not heated > 0.1 °C. A heating pattern that can induce thermal ablation was achieved in the vertebral body and the intervertebral disc. Adjacent structures and nerves were not heated in lethal levels. Thus, the Thiel embalmed human cadaver can be a safe and efficient model for preclinical study of application of MRgFUS on the upper lumbar spine.

  3. Pre-clinical in vivo models for the screening of bone biomaterials for oral/craniofacial indications: focus on small-animal models.

    PubMed

    Stavropoulos, Andreas; Sculean, Anton; Bosshardt, Dieter D; Buser, Daniel; Klinge, Björn

    2015-06-01

    Preclinical in vivo experimental studies are performed for evaluating proof-of-principle concepts, safety and possible unwanted reactions of candidate bone biomaterials before proceeding to clinical testing. Specifically, models involving small animals have been developed for screening bone biomaterials for their potential to enhance bone formation. No single model can completely recreate the anatomic, physiologic, biomechanic and functional environment of the human mouth and jaws. Relevant aspects regarding physiology, anatomy, dimensions and handling are discussed in this paper to elucidate the advantages and disadvantages of small-animal models. Model selection should be based not on the 'expertise' or capacities of the team, but rather on a scientifically solid rationale, and the animal model selected should reflect the question for which an answer is sought. The rationale for using heterotopic or orthotopic testing sites, and intraosseous, periosseous or extraskeletal defect models, is discussed. The paper also discusses the relevance of critical size defect modeling, with focus on calvarial defects in rodents. In addition, the rabbit sinus model and the capsule model in the rat mandible are presented and discussed in detail. All animal experiments should be designed with care and include sample-size and study-power calculations, thus allowing generation of meaningful data. Moreover, animal experiments are subject to ethical approval by the relevant authority. All procedures and the postoperative handling and care, including postoperative analgesics, should follow best practice. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Bosutinib: a review of preclinical studies in chronic myelogenous leukaemia.

    PubMed

    Boschelli, Frank; Arndt, Kim; Gambacorti-Passerini, Carlo

    2010-07-01

    Bosutinib (SKI-606) is an orally active Src and Abl kinase inhibitor presently in Phase III trials for treatment of chronic myelogenous leukaemia (CML), and in Phase II trials for treatment of breast cancer. Bosutinib is a potent antiproliferative and proapoptotic agent in CML cells and inhibits Bcr-Abl mediated signalling at nanomolar concentrations. Short-term administration of bosutinib causes regression of K562 and KU812 CML tumour xenografts. BaF3 murine myeloid cells expressing wild-type Bcr-Abl are sensitive to bosutinib treatment, as are BaF3 cells expressing many imatinib-resistant forms of Bcr-Abl. Recent studies indicate that bosutinib is active against a broader spectrum of kinases than originally believed. These additional inhibitory activities have interesting possibilities for further clinical development. This review will focus on preclinical studies supporting the clinical development of bosutinib for treatment of CML, with a discussion on the broader potential of this agent in other oncology indications. Copyright 2010 Elsevier Ltd. All rights reserved.

  5. Novel technology to prepare oral formulations for preclinical safety studies.

    PubMed

    Niwa, Toshiyuki; Hashimoto, Naofumi

    2008-02-28

    A novel method to prepare oral formulations, normally suspended dosage form, for preclinical safety studies in animals has been developed using a rotation/revolution mixer. Small hard balls made of zirconia were added to the mixing process to evaluate effectiveness in making a high quality suspension. The driving with balls loaded in the cylindrical container (vessel) of the mixer was quite efficient in dispersing and milling the particles of the active pharmaceutical ingredient (API) in an aqueous medium. The API powder and a small amount of oral aqueous medium (vehicle) were successfully mixed by the spinning motion of the balls in the vessel as though the paste-like suspension was kneaded with a mortar and pestle. It was found that the milled suspension with the mean size of 10-20microm could be prepared, in addition finer milling of less than 10microm could be achieved by selecting the material of vessel. Optimum driving conditions including mixing time, size and quantity of balls, and the standard operational procedure was established using compounds varying in physicochemical properties. The particle size and quantitative analysis by HPLC showed that the resultant suspension was well-milled and highly homogeneous with the nearly intended concentration of API. The proposed method established by this experiment could be applied to the actual safety studies in the real preparation scale of oral suspension.

  6. Improving treatment of neurodevelopmental disorders: recommendations based on preclinical studies.

    PubMed

    Homberg, Judith R; Kyzar, Evan J; Stewart, Adam Michael; Nguyen, Michael; Poudel, Manoj K; Echevarria, David J; Collier, Adam D; Gaikwad, Siddharth; Klimenko, Viktor M; Norton, William; Pittman, Julian; Nakamura, Shun; Koshiba, Mamiko; Yamanouchi, Hideo; Apryatin, Sergey A; Scattoni, Maria Luisa; Diamond, David M; Ullmann, Jeremy F P; Parker, Matthew O; Brown, Richard E; Song, Cai; Kalueff, Allan V

    2016-01-01

    Neurodevelopmental disorders (NDDs) are common and severely debilitating. Their chronic nature and reliance on both genetic and environmental factors makes studying NDDs and their treatment a challenging task. Herein, the authors discuss the neurobiological mechanisms of NDDs, and present recommendations on their translational research and therapy, outlined by the International Stress and Behavior Society. Various drugs currently prescribed to treat NDDs also represent a highly diverse group. Acting on various neurotransmitter and physiological systems, these drugs often lack specificity of action, and are commonly used to treat multiple other psychiatric conditions. There has also been relatively little progress in the development of novel medications to treat NDDs. Based on clinical, preclinical and translational models of NDDs, our recommendations cover a wide range of methodological approaches and conceptual strategies. To improve pharmacotherapy and drug discovery for NDDs, we need a stronger emphasis on targeting multiple endophenotypes, a better dissection of genetic/epigenetic factors or "hidden heritability," and a careful consideration of potential developmental/trophic roles of brain neurotransmitters. The validity of animal NDD models can be improved through discovery of novel (behavioral, physiological and neuroimaging) biomarkers, applying proper environmental enrichment, widening the spectrum of model organisms, targeting developmental trajectories of NDD-related behaviors and comorbid conditions beyond traditional NDDs. While these recommendations cannot be addressed all in once, our increased understanding of NDD pathobiology may trigger innovative cross-disciplinary research expanding beyond traditional methods and concepts.

  7. Osteogenic Potential of Dental Mesenchymal Stem Cells in Preclinical Studies: A Systematic Review Using Modified ARRIVE and CONSORT Guidelines

    PubMed Central

    Ramamoorthi, Murali; Bakkar, Mohammed; Jordan, Jack; Tran, Simon D.

    2015-01-01

    Background and Objective. Dental stem cell-based tissue engineered constructs are emerging as a promising alternative to autologous bone transfer for treating bone defects. The purpose of this review is to systematically assess the preclinical in vivo and in vitro studies which have evaluated the efficacy of dental stem cells on bone regeneration. Methods. A literature search was conducted in Ovid Medline, Embase, PubMed, and Web of Science up to October 2014. Implantation of dental stem cells in animal models for evaluating bone regeneration and/or in vitro studies demonstrating osteogenic potential of dental stem cells were included. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were used to ensure the quality of the search. Modified ARRIVE (Animal research: reporting in invivo experiments) and CONSORT (Consolidated reporting of trials) were used to critically analyze the selected studies. Results. From 1914 citations, 207 full-text articles were screened and 137 studies were included in this review. Because of the heterogeneity observed in the studies selected, meta-analysis was not possible. Conclusion. Both in vivo and in vitro studies indicate the potential use of dental stem cells in bone regeneration. However well-designed randomized animal trials are needed before moving into clinical trials. PMID:26106427

  8. Preclinical safety studies on autologous cultured human skin fibroblast transplantation.

    PubMed

    Zeng, Wei; Zhang, Shuying; Liu, Dai; Chai, Mi; Wang, Jiaqi; Zhao, Yuming

    2014-01-01

    Recently, FDA approved the clinical use of autologous fibroblasts (LAVIV™) for the improvement of nasolabial fold wrinkles in adults. The use of autologous fibroblasts for the augmentation of dermal and subcutaneous defects represents a potentially exciting natural alternative to the use of other filler materials for its long-term corrective ability and absence of allergic adverse effects proved by clinical application. However, compared to the clinical evidence, preclinical studies are far from enough. In this study, human skin-derived fibroblasts were cultured and expanded for both in vitro and in vivo observations. In vitro, the subcultured fibroblasts were divided into two groups. One set of cells underwent cell cycle and karyotype analysis at passages 5 and 10. The second group of cells was cocultured in medium with different concentrations of human skin extract D for the measurement of collagen concentration and cell count. In vivo, the subcultured fibroblasts were injected into nude mice subcutaneously. Biopsies were taken for morphology observation and specific collagen staining at 1, 2, and 3 months after injection. The results in vitro showed no significant differences in cell cycle distribution between passages 5 and 10. Cell proliferation and secretion were inhibited as the concentration of extract D increased. In vivo, the fibroblasts were remarkably denser on the experimental side with no dysplastic cells. Mitotic cells were easily observed at the end of the first month but were rare at the end of the third month. Type III collagen was detected at the end of the first month, while collagen type I was positive at the end of the second month. The content of both collagens increased as time passed. The above results indicated that the use of the autologous fibroblasts was safe, providing a basic support for clinical use of fibroblasts.

  9. Breast cancer osteomimicry and its role in bone specific metastasis; an integrative, systematic review of preclinical evidence.

    PubMed

    Awolaran, Olugbenga; Brooks, Susan A; Lavender, Verna

    2016-12-01

    Metastasis accounts for most of the deaths from breast cancer and the preference of invasive breast cancer metastasising to bone has been widely reported. However, the biological basis of breast cancer osteotropism is not fully understood. This paper provides, for the first time, an integrative, systematic review of evidence of molecular factors that have functional roles in the homing of metastatic breast cancer to the bone. Pubmed, Web of Science and EBSCOhost were searched using keywords and synonyms for molecular, metastasis, breast cancer and bone to identify articles published between January 2004 and August 2016. 4491 potentially relevant citations were retrieved. 63 articles met the inclusion criteria, which were primary studies reporting evidence of molecular factors that have functional roles in predisposing breast cancer bone metastasis in vivo. 12 of those 63 articles that additionally met quality criteria were included in the review. Extracted data were tabulated and key findings that indicated biological mechanisms involved in breast cancer metastasis to bone were synthesised. 15 proteins expressed by breast cancer cells were identified as factors that mediate breast cancer bone metastasis: ICAM-1, cadherin-11, osteoactivin, bone sialoprotein, CCN3, IL-11, CCL2, CITED2, CXCR4, CTGF, OPN, CX3CR1, TWIST1, adrenomedullin and Enpp1. Upregulation or overexpression of one or more of them by breast cancer cells resulted in increased breast cancer metastasis to bone in vivo, except for CCL2 where bone-metastatic cells showed a reduced expression of this factor. All factors identified, here expressed by breast cancer cells, are proteins that are normally expressed in the bone microenvironment and linked to physiologic bone functions. All have a functional role in one of more of the following: cell proliferation and differentiation, bone mineralization and remodelling, cell adhesion and/or chemokine signalling. Six of them (cadherin-11, ICAM-1, OPN, CX3CR1

  10. Iron Deprivation Treatment of Breast Cancer: Preclinical Studies

    DTIC Science & Technology

    1999-01-01

    interest in breast cancer patients who have undergone bone marrow transplantation and are experiencing acute graft versus host disease. We are now...of acute graft versus host disease in breast cancer patients undergoing bone marrow transplantation . 5. DFO and tamoxifen appear to interact in a

  11. Our evolving science: studying the influence of sex in preclinical research.

    PubMed

    Mazure, Carolyn M

    2016-01-01

    The policy announcement by the National Institutes of Health that sex should be considered as a relevant variable in preclinical research has sparked considerable debate. This debate has largely centered on specific concerns regarding how the policy will be implemented. However, others have reacted to the new policy by calling into question the capacity of preclinical science to generate data that can be useful to human health. This commentary examines the basis for this contention and maintains that it is essential to expand our scientific efforts to include the influence of sex on the biology and behavior that is studied in preclinical investigations.

  12. Standard Operating Procedures (SOPs) for Evaluating the Heart in Preclinical Studies of Duchenne Muscular Dystrophy.

    PubMed

    Duan, Dongsheng; Rafael-Fortney, Jill A; Blain, Alison; Kass, David A; McNally, Elizabeth M; Metzger, Joseph M; Spurney, Christopher F; Kinnett, Kathi

    2016-02-01

    A recent working group meeting focused on contemporary cardiac issues in Duchenne muscular dystrophy (DMD) was hosted by the National Heart, Lung, and Blood Institute in collaboration with the Parent Project Muscular Dystrophy. An outcome of this meeting was to provide freely available detailed protocols for preclinical animal studies. The goal of these protocols is to improve the quality and reproducibility of cardiac preclinical studies aimed at developing new therapeutics for the prevention and treatment of DMD cardiomyopathy.

  13. Bone marrow transplantation generates immature oocytes and rescues long-term fertility in a preclinical mouse model of chemotherapy-induced premature ovarian failure.

    PubMed

    Lee, Ho-Joon; Selesniemi, Kaisa; Niikura, Yuichi; Niikura, Teruko; Klein, Rachael; Dombkowski, David M; Tilly, Jonathan L

    2007-08-01

    Although early menopause frequently occurs in female cancer patients after chemotherapy (CTx), bone marrow (BM) transplantation (BMT) has been linked to an unexplained return of ovarian function and fertility in some survivors. Studies modeling this in mice have shown that BMT generates donor-derived oocytes in CTx-treated recipients. However, a subsequent report claimed that ovulated eggs are not derived from BM and that BM-derived oocytes reported previously are misidentified immune cells. This study was conducted to further clarify the impact of BMT on female reproductive function after CTx using a preclinical mouse model. Female mice were administered CTx followed by BMT using coat color-mismatched female donors. After housing with males, the number of pregnancies and offspring genotype were recorded. For cell tracking, BM from germline-specific green fluorescent protein-transgenic mice was transplanted into CTx-treated wild-type recipients. Immune cells were sorted from blood and analyzed for germline markers. BMT rescued long-term fertility in CTx-treated females, but all offspring were derived from the recipient germline. Cell tracking showed that donor-derived oocytes were generated in ovaries of recipients after BMT, and two lines of evidence dispelled the claim that these oocytes are misidentified immune cells. These data from a preclinical mouse model validate a testable clinical strategy for preserving or resurrecting ovarian function and fertility in female cancer patients after CTx, thus aligning with recommendations of the 2005 National Cancer Institute Breast Cancer Progress Review Group and President's Cancer Panel to prioritize research efforts aimed at improving the quality of life in cancer survivors.

  14. Pomegranate Peel Extract Prevents Bone Loss in a Preclinical Model of Osteoporosis and Stimulates Osteoblastic Differentiation in Vitro

    PubMed Central

    Spilmont, Mélanie; Léotoing, Laurent; Davicco, Marie-Jeanne; Lebecque, Patrice; Miot-Noirault, Elisabeth; Pilet, Paul; Rios, Laurent; Wittrant, Yohann; Coxam, Véronique

    2015-01-01

    The nutritional benefits of pomegranate have attracted great scientific interest. The pomegranate, including the pomegranate peel, has been used worldwide for many years as a fruit with medicinal activity, mostly antioxidant properties. Among chronic diseases, osteoporosis, which is associated with bone remodelling impairment leading to progressive bone loss, could eventually benefit from antioxidant compounds because of the involvement of oxidative stress in the pathogenesis of osteopenia. In this study, with in vivo and ex vivo experiments, we investigated whether the consumption of pomegranate peel extract (PGPE) could limit the process of osteopenia. We demonstrated that in ovariectomized (OVX) C57BL/6J mice, PGPE consumption was able to significantly prevent the decrease in bone mineral density (−31.9%; p < 0.001 vs. OVX mice) and bone microarchitecture impairment. Moreover, the exposure of RAW264.7 cells to serum harvested from mice that had been given a PGPE-enriched diet elicited reduced osteoclast differentiation and bone resorption, as shown by the inhibition of the major osteoclast markers. In addition, PGPE appeared to substantially stimulate osteoblastic MC3T3-E1 alkaline phosphatase (ALP) activity at day 7, mineralization at day 21 and the transcription level of osteogenic markers. PGPE may be effective in preventing the bone loss associated with ovariectomy in mice, and offers a promising alternative for the nutritional management of this disease. PMID:26569295

  15. Methodological Rigor in Preclinical Cardiovascular Studies: Targets to Enhance Reproducibility and Promote Research Translation.

    PubMed

    Ramirez, F Daniel; Motazedian, Pouya; Jung, Richard G; Di Santo, Pietro; MacDonald, Zachary D; Moreland, Robert; Simard, Trevor; Clancy, Aisling A; Russo, Juan J; Welch, Vivian A; Wells, George A; Hibbert, Benjamin

    2017-06-09

    Methodological sources of bias and suboptimal reporting contribute to irreproducibility in preclinical science and may negatively affect research translation. Randomization, blinding, sample size estimation, and considering sex as a biological variable are deemed crucial study design elements to maximize the quality and predictive value of preclinical experiments. To examine the prevalence and temporal patterns of recommended study design element implementation in preclinical cardiovascular research. All articles published over a 10-year period in 5 leading cardiovascular journals were reviewed. Reports of in vivo experiments in nonhuman mammals describing pathophysiology, genetics, or therapeutic interventions relevant to specific cardiovascular disorders were identified. Data on study design and animal model use were collected. Citations at 60 months were additionally examined as a surrogate measure of research impact in a prespecified subset of studies, stratified by individual and cumulative study design elements. Of 28 636 articles screened, 3396 met inclusion criteria. Randomization was reported in 21.8%, blinding in 32.7%, and sample size estimation in 2.3%. Temporal and disease-specific analyses show that the implementation of these study design elements has overall not appreciably increased over the past decade, except in preclinical stroke research, which has uniquely demonstrated significant improvements in methodological rigor. In a subset of 1681 preclinical studies, randomization, blinding, sample size estimation, and inclusion of both sexes were not associated with increased citations at 60 months. Methodological shortcomings are prevalent in preclinical cardiovascular research, have not substantially improved over the past 10 years, and may be overlooked when basing subsequent studies. Resultant risks of bias and threats to study validity have the potential to hinder progress in cardiovascular medicine as preclinical research often precedes and

  16. Preclinical animal study and clinical trail of modified extraoral craniofacial implants.

    PubMed

    Petrovic, L; Schlegel, K A; Wiltfang, J; Neukam, F W; Rupprecht, S

    2007-01-01

    We report on our experience using a new endosseous implant designed to provide sufficient retention to various types of facial prostheses. In a preclinical animal experiment implants (N=12, 4 x 3.5 mm) were placed in the frontal calvarial region of nine adult pigs. The animals were sacrificed at 2, 4 and 8 weeks to evaluate the implant incorporation microradiographically. The clinical outcome and patient satisfaction of implant-retained prostheses were evaluated in a group of 10 patients with facial defects by using clinical assessment and standardized questionnaires for patients and relatives. In the prospective clinical study 33 identical modified implants for extraoral anchorage were placed for the fixation of various prostheses in the midfacial (eye, nose) and ear regions in the course of a clinical trial and observed over a follow-up period of 34 months. The bone-implant contact in the animal experiment reached 31% (+/-2) at 2 weeks, 39% (+/-1) after 4 weeks and 51% (+/-5) at 8 weeks. In the clinical trial, no implants were lost and all implants remained osseointegrated as confirmed clinically and radiographically, providing a stable prosthetic restoration. The analysis of the questionnaire indicates an improvement of the quality of life of patients with respect to aesthetic and psychological well-being. The results demonstrate that extraoral implants not only achieve sufficient osseointegration but also show good clinical handling and easy fixation possibilities for prosthetic anchorage.

  17. Intravital microscopy as a tool to study drug delivery in preclinical studies

    PubMed Central

    Amornphimoltham, Panomwat; Masedunskas, Andrius; Weigert, Roberto

    2010-01-01

    The technical developments in the field of non-linear microscopy have made intravital microscopy one of the most successful techniques for studying physiological and pathological processes in live animals. Intravital microscopy has been utilized to address many biological questions in basic research and is now a fundamental tool for preclinical studies, with an enormous potential for clinical applications. The ability to dynamically image cellular and subcellular structures combined with the possibility to perform longitudinal studies have empowered investigators to use this discipline to study the mechanisms of action of therapeutic agents and assess the efficacy on their targets in vivo. The goal of this review is to provide a general overview of the recent advances in intravital microscopy and to discuss some of its applications in preclinical studies. PMID:20933026

  18. The effect of learning styles and study behavior on success of preclinical students in pharmacology

    PubMed Central

    Asci, Halil; Kulac, Esin; Sezik, Mekin; Cankara, F. Nihan; Cicek, Ekrem

    2016-01-01

    Objectives: To evaluate the effect of learning styles and study behaviors on preclinical medical students’ pharmacology exam scores in a non-Western setting. Materials and Methods: Grasha–Reichmann Student Learning Study Scale and a modified Study Behavior Inventory were used to assess learning styles and study behaviors of preclinical medical students (n = 87). Logistic regression models were used to evaluate the independent effect of gender, age, learning style, and study behavior on pharmacology success. Results: Collaborative (40%) and competitive (27%) dominant learning styles were frequent in the cohort. The most common study behavior subcategories were study reading (40%) and general study habits (38%). Adequate listening and note-taking skills were associated with pharmacology success, whereas students with adequate writing skills had lower exam scores. These effects were independent of gender. Conclusions: Preclinical medical students’ study behaviors are independent predictive factors for short-term pharmacology success. PMID:26997716

  19. The effect of learning styles and study behavior on success of preclinical students in pharmacology.

    PubMed

    Asci, Halil; Kulac, Esin; Sezik, Mekin; Cankara, F Nihan; Cicek, Ekrem

    2016-01-01

    To evaluate the effect of learning styles and study behaviors on preclinical medical students' pharmacology exam scores in a non-Western setting. Grasha-Reichmann Student Learning Study Scale and a modified Study Behavior Inventory were used to assess learning styles and study behaviors of preclinical medical students (n = 87). Logistic regression models were used to evaluate the independent effect of gender, age, learning style, and study behavior on pharmacology success. Collaborative (40%) and competitive (27%) dominant learning styles were frequent in the cohort. The most common study behavior subcategories were study reading (40%) and general study habits (38%). Adequate listening and note-taking skills were associated with pharmacology success, whereas students with adequate writing skills had lower exam scores. These effects were independent of gender. Preclinical medical students' study behaviors are independent predictive factors for short-term pharmacology success.

  20. Bone vascularization: a way to study bone microarchitecture?

    NASA Astrophysics Data System (ADS)

    Blery, P.; Autrusseau, F.; Crauste, E.; Freuchet, Erwan; Weiss, Pierre; Guédon, J.-P.; Amouriq, Y.

    2014-03-01

    Trabecular bone and its microarchitecture are of prime importance for health. Studying vascularization helps to better know the relationship between bone and vascular microarchitecture. This research is an animal study (nine Lewis rats), based on the perfusion of vascularization by a contrast agent (a mixture of 50% barium sulfate with 1.5% of gelatin) before euthanasia. The samples were studied by micro CT at a resolution of 9μm. Softwares were used to show 3D volumes of bone and vessels, to calculate bone and vessels microarchitecture parameters. This study aims to understand simultaneously the bone microarchitecture and its vascular microarchitecture.

  1. Translation of stem cell research: points to consider in designing preclinical animal studies.

    PubMed

    Frey-Vasconcells, Joyce; Whittlesey, Kevin J; Baum, Elona; Feigal, Ellen G

    2012-05-01

    Stem cell-based therapies hold tremendous promise for the treatment of serious diseases and injuries. Although hematopoietic stem cell transplantation is routinely used as part of the treatment regime for some malignancies and genetic diseases, most stem cell-based therapeutic products are investigational and still require preclinical and clinical studies to support their many novel therapeutic uses. Because of the multiple sources of stem cells, the plethora of potential applications, and the novel mechanism of action of stem cell-based therapies, there is no single set of universal guidance documents that can be used to inform the preclinical development path for these therapeutics. Specific technical issues relating to the transplantation of human cells in animals, new delivery procedures, and laborious methods to characterize transplanted cells can present further challenges in the design and execution of preclinical animal studies for stem cell-based therapeutic products. In this article, we outline important parameters to guide the design of preclinical studies for stem cell-based therapeutics. In addition, we review the types of preclinical studies that should be considered depending on the nature and specific use of the intended stem cell therapeutic product. Finally, we describe important considerations in the design and execution of specific studies to monitor the efficacy, toxicity, biodistribution, and tumorigenicity of stem cell-based therapeutics.

  2. Towards environmental construct validity in animal models of CNS disorders: optimizing translation of preclinical studies.

    PubMed

    Burrows, Emma L; Hannan, Anthony J

    2013-08-01

    There is an enormous demand for new therapeutic interventions for a range of major disorders. The majority of clinical trials in recent years have been unsuccessful despite highly promising preclinical data. Therefore, an urgent issue confronting both the academic and commercial medical research sectors is how to optimize translation of preclinical studies. The vast majority of preclinical studies are currently performed using laboratory mice and rats. We will discuss the various opportunities for optimization of animal models of CNS disorders. One limitation of current approaches is that most studies are conducted on sedentary, unstimulated animals with unlimited access to food in the home cage, thus leading to metabolic and physiological compromise. Environmental enrichment, which enhances sensory stimulation, cognitive activity and physical exercise, has been demonstrated to induce dramatic effects on brain and behavior in both wild-type and genetically modified rodent models, relative to standard-housed littermate controls. Environmental enrichment also exerts beneficial effects outside the CNS, such as a reduction in excess body fat. We propose that therapeutic interventions which are found to show promise in standard-housed preclinical models should be subsequently tested under conditions of greater environmental enrichment to identify therapeutics which continue to show efficacy in housing contexts of superior 'environmental construct validity'. Other possible approaches to optimize the quality, validity and reporting of preclinical studies in animal models are also discussed.

  3. Monte Carlo simulation on pre-clinical irradiation: A heterogeneous phantom study on monoenergetic kilovoltage photon beams

    NASA Astrophysics Data System (ADS)

    Chow, James C. L.

    2012-10-01

    This study investigated radiation dose variations in pre-clinical irradiation due to the photon beam energy and presence of tissue heterogeneity. Based on the same mouse computed tomography image dataset, three phantoms namely, heterogeneous, homogeneous and bone homogeneous were used. These phantoms were generated by overriding the relative electron density of no voxel (heterogeneous), all voxel (homogeneous) and the bone voxel (bone homogeneous) to one. 360° photon arcs with beam energies of 50 - 1250 keV were used in mouse irradiations. Doses in the above phantoms were calculated using the EGSnrc-based DOSXYZnrc code through the DOSCTP. Monte Carlo simulations were carried out in parallel using multiple nodes in a high-performance computing cluster. It was found that the dose conformity increased with the increase of the photon beam energy from the keV to MeV range. For the heterogeneous mouse phantom, increasing the photon beam energy from 50 keV to 1250 keV increased seven times the dose deposited at the isocenter. For the bone dose enhancement, the mean dose was 2.7 times higher when the bone heterogeneity was not neglected using the 50 keV photon beams in the mouse irradiation. Bone dose enhancement affecting the mean dose was found in the photon beams with energy range of 50 - 200 keV and the dose enhancement decreased with an increase of the beam energy. Moreover, the MeV photon beam had a higher dose at the isocenter, and a better dose conformity compared to the keV beam.

  4. Magnetic Fluid Hyperthermia for Bladder Cancer: A Preclinical Dosimetry Study

    PubMed Central

    Oliveira, Tiago R.; Stauffer, Paul R.; Lee, Chen-Ting; Landon, Chelsea D.; Etienne, Wiguins; Ashcraft, Kathleen A.; McNerny, Katie L.; Mashal, Alireza; Nouls, John; Maccarini, Paolo F.; Beyer, Wayne F.; Inman, Brant; Dewhirst, Mark W.

    2014-01-01

    Purpose This paper describes a preclinical investigation of the feasibility of thermotherapy treatment of bladder cancer with Magnetic Fluid Hyperthermia (MFH), performed by analyzing the thermal dosimetry of nanoparticle heating in a rat bladder model. Materials and Methods The bladders of twenty-five female rats were instilled with magnetite-based nanoparticles, and hyperthermia was induced using a novel small animal magnetic field applicator (Actium Biosystems, Boulder, CO). We aimed to increase the bladder lumen temperature to 42°C in <10 min and maintain that temperature for 60 min. Temperatures were measured within the bladder lumen and throughout the rat with seven fiberoptic probes (OpSens Technologies, Quebec, Canada). An MRI analysis was used to confirm the effectiveness of the catheterization method to deliver and maintain various nanoparticle volumes within the bladder. Thermal dosimetry measurements recorded the temperature rise of rat tissues for a variety of nanoparticle exposure conditions. Results Thermal dosimetry data demonstrated our ability to raise and control the temperature of rat bladder lumen ≥1°C/min to a steady-state of 42°C with minimal heating of surrounding normal tissues. MRI scans confirmed the homogenous nanoparticle distribution throughout the bladder. Conclusion These data demonstrate that our MFH system with magnetite-based nanoparticles provide well-localized heating of rat bladder lumen with effective control of temperature in the bladder and minimal heating of surrounding tissues. PMID:24050253

  5. Models for preclinical studies in aging-related disorders: One is not for all

    PubMed Central

    Santulli, Gaetano; Borras, Consuelo; Bousquet, Jean; Calzà, Laura; Cano, Antonio; Illario, Maddalena; Franceschi, Claudio; Liotta, Giuseppe; Maggio, Marcello; Molloy, William D.; Montuori, Nunzia; O’Caoimh, Rónán; Orfila, Francesc; Rauter, Amelia P.; Santoro, Aurelia; Iaccarino, Guido

    2015-01-01

    Preclinical studies are essentially based on animal models of a particular disease. The primary purpose of preclinical efficacy studies is to support generalization of treatment–effect relationships to human subjects. Researchers aim to demonstrate a causal relationship between an investigational agent and a disease-related phenotype in such models. Numerous factors can muddle reliable inferences about such cause-effect relationships, including biased outcome assessment due to experimenter expectations. For instance, responses in a particular inbred mouse might be specific to the strain, limiting generalizability. Selecting well-justified and widely acknowledged model systems represents the best start in designing preclinical studies, especially to overcome any potential bias related to the model itself. This is particularly true in the research that focuses on aging, which carries unique challenges, mainly attributable to the fact that our already long lifespan makes designing experiments that use people as subjects extremely difficult and largely impractical. PMID:27042427

  6. Anticancer activity of tolfenamic acid in medulloblastoma: a preclinical study.

    PubMed

    Eslin, Don; Lee, Chris; Sankpal, Umesh T; Maliakal, Pius; Sutphin, Robert M; Abraham, Liz; Basha, Riyaz

    2013-10-01

    Medulloblastoma (MB) is the most common malignancy in children arising in the brain. Morbidities associated with intensive therapy are serious concerns in treating MB. Our aim was to identify novel targets and agents with less toxicity for treating MB. Specificity protein 1 (Sp1) transcription factor regulates several genes involved in cell proliferation and cell survival including survivin, an inhibitor of apoptosis protein. We previously showed that tolfenamic acid (TA), a nonsteroidal anti-inflammatory drug, inhibits neuroblastoma cell growth by targeting Sp1. We investigated the anticancer activity of TA using human MB cell lines and a mouse xenograft model. DAOY and D283 cells were treated with vehicle (dimethyl sulfoxide) or TA (5-50 μg/ml), and cell viability was measured at 1-3 days posttreatment. TA inhibited MB cell growth in a time- and dose-dependent manner. MB cells were treated with vehicle or TA (10 μg/ml), and the effect on cell apoptosis was measured. Apoptosis was analyzed by flow cytometry (annexin V staining), and caspase 3/7 activity was determined using Caspase-Glo kit. The expression of Sp1, cleaved poly(ADP-ribose) polymerase (c-PARP), and survivin was determined by Western blot analysis. TA inhibited the expression of Sp1 and survivin and upregulated c-PARP. Athymic nude mice were subcutaneously injected with D283 cells and treated with TA (50 mg/kg, three times per week) for 4 weeks. TA caused a decrease of ~40 % in tumor weight and volume. The tumor growth inhibition was accompanied by a decrease in Sp1 and survivin expression in tumor tissue. These preclinical data demonstrate that TA acts as an anticancer agent in MB potentially targeting Sp1 and survivin.

  7. Drugs under preclinical and clinical study for treatment of acute and chronic lymphoblastic leukemia

    PubMed Central

    Jacob, Joe Antony; Salmani, Jumah Masoud Mohammad; Chen, Baoan

    2016-01-01

    Targeted therapy has modernized the treatment of both chronic and acute lymphoblastic leukemia. The introduction of monoclonal antibodies and combinational drugs has increased the survival rate of patients. Preclinical studies with various agents have resulted in positive outputs with Phase III trial drugs and monoclonal antibodies entering clinical trials. Most of the monoclonal antibodies target the CD20 and CD22 receptors. This has led to the approval of a few of these drugs by the US Food and Drug Administration. This review focuses on the drugs under preclinical and clinical study in the ongoing efforts for treatment of acute and chronic lymphoblastic leukemia. PMID:27382259

  8. Preclinical usability study of multiple augmented reality concepts for K-wire placement.

    PubMed

    Fischer, Marius; Fuerst, Bernhard; Lee, Sing Chun; Fotouhi, Javad; Habert, Severine; Weidert, Simon; Euler, Ekkehard; Osgood, Greg; Navab, Nassir

    2016-06-01

    In many orthopedic surgeries, there is a demand for correctly placing medical instruments (e.g., K-wire or drill) to perform bone fracture repairs. The main challenge is the mental alignment of X-ray images acquired using a C-arm, the medical instruments, and the patient, which dramatically increases in complexity during pelvic surgeries. Current solutions include the continuous acquisition of many intra-operative X-ray images from various views, which will result in high radiation exposure, long surgical durations, and significant effort and frustration for the surgical staff. This work conducts a preclinical usability study to test and evaluate mixed reality visualization techniques using intra-operative X-ray, optical, and RGBD imaging to augment the surgeon's view to assist accurate placement of tools. We design and perform a usability study to compare the performance of surgeons and their task load using three different mixed reality systems during K-wire placements. The three systems are interventional X-ray imaging, X-ray augmentation on 2D video, and 3D surface reconstruction augmented by digitally reconstructed radiographs and live tool visualization. The evaluation criteria include duration, number of X-ray images acquired, placement accuracy, and the surgical task load, which are observed during 21 clinically relevant interventions performed by surgeons on phantoms. Finally, we test for statistically significant improvements and show that the mixed reality visualization leads to a significantly improved efficiency. The 3D visualization of patient, tool, and DRR shows clear advantages over the conventional X-ray imaging and provides intuitive feedback to place the medical tools correctly and efficiently.

  9. Tissue Engineering of the Urethra: A Systematic Review and Meta-analysis of Preclinical and Clinical Studies.

    PubMed

    Versteegden, Luuk R M; de Jonge, Paul K J D; IntHout, Joanna; van Kuppevelt, Toin H; Oosterwijk, Egbert; Feitz, Wout F J; de Vries, Rob B M; Daamen, Willeke F

    2017-10-01

    Urethra repair by tissue engineering has been extensively studied in laboratory animals and patients, but is not routinely used in clinical practice. To systematically investigate preclinical and clinical evidence of the efficacy of tissue engineering for urethra repair in order to stimulate translation of preclinical studies to the clinic. A systematic search strategy was applied in PubMed and EMBASE. Studies were independently screened for relevance by two reviewers, resulting in 80 preclinical and 23 clinical studies of which 63 and 13 were selected for meta-analysis to assess side effects, functionality, and study completion. Analyses for preclinical and clinical studies were performed separately. Full circumferential and inlay procedures were assessed independently. Evaluated parameters included seeding of cells and type of biomaterial. Meta-analysis revealed that cell seeding significantly reduced the probability of encountering side effects in preclinical studies. Remarkably though, cells were only sparsely used in the clinic (4/23 studies) and showed no significant reduction of side effects. ln 21 out of 23 clinical studies, decellularized templates were used, while in preclinical studies other biomaterials showed promising outcomes as well. No direct comparison to current clinical practice could be made due to the limited number of randomized controlled studies. Due to a lack of controlled (pre)clinical studies, the efficacy of tissue engineering for urethra repair could not be determined. Meta-analysis outcome measures were similar to current treatment options described in literature. Surprisingly, it appeared that favorable preclinical results, that is inclusion of cells, were not translated to the clinic. Improved (pre)clinical study designs may enhance clinical translation. We reviewed all available literature on urethral tissue engineering to assess the efficacy in preclinical and clinical studies. We show that improvements to (pre)clinical study

  10. Exploratory Study of Factors Related to Educational Scores of First Preclinical Year Medical Students

    ERIC Educational Resources Information Center

    Sitticharoon, Chantacha; Srisuma, Sorachai; Kanavitoon, Sawita; Summachiwakij, Sarawut

    2014-01-01

    The relationships among the scores of major subjects taught in the first preclinical year of a Thai medical school, previous academic achievements, and daily life activities are rarely explored. We therefore performed an exploratory study identifying various factors possibly related to the educational scores of these medical students.…

  11. Exploratory Study of Factors Related to Educational Scores of First Preclinical Year Medical Students

    ERIC Educational Resources Information Center

    Sitticharoon, Chantacha; Srisuma, Sorachai; Kanavitoon, Sawita; Summachiwakij, Sarawut

    2014-01-01

    The relationships among the scores of major subjects taught in the first preclinical year of a Thai medical school, previous academic achievements, and daily life activities are rarely explored. We therefore performed an exploratory study identifying various factors possibly related to the educational scores of these medical students.…

  12. Common data elements and data management: Remedy to cure underpowered preclinical studies.

    PubMed

    Lapinlampi, Niina; Melin, Esbjörn; Aronica, Eleonora; Bankstahl, Jens P; Becker, Albert; Bernard, Cristophe; Gorter, Jan A; Gröhn, Olli; Lipsanen, Anu; Lukasiuk, Katarzyna; Löscher, Wolfgang; Paananen, Jussi; Ravizza, Teresa; Roncon, Paolo; Simonato, Michele; Vezzani, Annamaria; Kokaia, Merab; Pitkänen, Asla

    2017-01-01

    Lack of translation of data obtained in preclinical trials to clinic has kindled researchers to develop new methodologies to increase the power and reproducibility of preclinical studies. One approach relates to harmonization of data collection and analysis, and has been used for a long time in clinical studies testing anti-seizure drugs. EPITARGET is a European Union FP7-funded research consortium composed of 18 partners from 9 countries. Its main research objective is to identify biomarkers and develop treatments for epileptogenesis. As the first step of harmonization of procedures between laboratories, EPITARGET established working groups for designing project-tailored common data elements (CDEs) and case report forms (CRFs) to be used in data collection and analysis. Eight major modules of CRFs were developed, presenting >1000 data points for each animal. EPITARGET presents the first single-project effort for harmonization of preclinical data collection and analysis in epilepsy research. EPITARGET is also anticipating the future challenges and requirements in a larger-scale preclinical harmonization of epilepsy studies, including training, data management expertise, cost, location, data safety and continuity of data repositories during and after funding period, and incentives motivating for the use of CDEs.

  13. Demonstrating efficacy in preclinical studies of cellular therapies for spinal cord injury - how much is enough?

    PubMed

    Kwon, Brian K; Soril, Lesley J J; Bacon, Mark; Beattie, Michael S; Blesch, Armin; Bresnahan, Jacqueline C; Bunge, Mary Bartlett; Dunlop, Sarah A; Fehlings, Michael G; Ferguson, Adam R; Hill, Caitlin E; Karimi-Abdolrezaee, Soheila; Lu, Paul; McDonald, John W; Müller, Hans W; Oudega, Martin; Rosenzweig, Ephron S; Reier, Paul J; Silver, Jerry; Sykova, Eva; Xu, Xiao-Ming; Guest, James D; Tetzlaff, Wolfram

    2013-10-01

    Cellular therapies represent a novel treatment approach for spinal cord injury (SCI), with many different cellular substrates showing promise in preclinical animal models of SCI. Considerable interest therefore exists to translate such cellular interventions into human clinical trials. Balanced against the urgency for clinical translation is the desire to establish the robustness of a cellular therapy's efficacy in preclinical studies, thereby optimizing its chances of succeeding in human trials. Uncertainty exists, however, on the extent to which a therapy needs to demonstrate efficacy in the preclinical setting in order to justify the initiation of a lengthy, expensive, and potentially risky clinical trial. The purpose of this initiative was to seek perspectives on the level of evidence required in experimental studies of cellular therapies before proceeding with clinical trials of SCI. We conducted a survey of 27 SCI researchers actively involved in either preclinical and/or clinical research of cellular interventions for SCI, and then held a focus group meeting to facilitate more in-depth discussion around a number of translational issues. These included: the use of animal models, the use of injury models and mechanisms, the window for demonstrating efficacy, independent replication, defining "relevant, meaningful efficacy" in preclinical studies, and the expectation of therapeutic benefits for cellular interventions. Here we present the key findings from both the survey and focus group meeting in order to summarize and underscore the areas of consensus and disagreement amongst the sampled researchers. It is anticipated that the knowledge generated from this initiative will help to incite future scientific discussions and expert guidelines towards translation of a cell therapy for persons with SCI.

  14. [Small animal image-guided radiotherapy: A new era for preclinical studies].

    PubMed

    Delpon, G; Frelin-Labalme, A-M; Heinrich, S; Beaudouin, V; Noblet, C; Begue, M; Le Deroff, C; Pouzoulet, F; Chiavassa, S

    2016-02-01

    Preclinical external beam radiotherapy irradiations used to be delivered with a static broad beam. To promote the transfer from animal to man, the preclinical treatment techniques dedicated to the animal have been optimized to be similar to those delivered to patients in clinical practice. In this context, preclinical irradiators have been developed. Due to the small sizes of the animals, and the irradiation beams, the scaling to the small animal dimensions involves specific problems. Reducing the size and energy of the irradiation beams require very high technical performance, especially for the mechanical stability of the irradiator and the spatial resolution of the imaging system. In addition, the determination of the reference absorbed dose rate must be conducted with a specific methodology and suitable detectors. To date, three systems are used for preclinical studies in France. The aim of this article is to present these new irradiators dedicated to small animals from a physicist point of view, including the commissioning and the quality control. Copyright © 2016 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  15. Development of an NIH consortium for preclinicAl AssESsment of CARdioprotective therapies (CAESAR): a paradigm shift in studies of infarct size limitation.

    PubMed

    Lefer, David J; Bolli, Roberto

    2011-01-01

    An estimated 935,000 Americans suffer a myocardial infarction every year; because their prognosis is determined by the size of the infarct, reducing infarct size is of paramount importance to alleviate morbidity and mortality. For 40 years, the National Heart, Lung, and Blood Institute (NHLBI) has invested enormous resources (at least several hundred million dollars) in preclinical studies aimed at developing infarct-sparing therapies, and several hundred (if not thousands) therapies have been claimed to limit infarct size in preclinical models. Unfortunately, due largely to methodological problems, this enormous investment has not produced any notable clinical application, and no cardioprotective therapy is currently available for clinical use. Clearly, after 40 years of futile efforts, a new approach is needed to overcome the problems that have impeded the translation of cardioprotective therapies. The time has come to apply to preclinical research on cardioprotection, the same standards of scientific rigor that are applied to clinical trials. In compliance with the recommendations of an National Heart, Lung, and Blood Institute (NHLBI)-sponsored workshop held in June 2003 and using the clinical trial networks established by the NHLBI as a model for developing a collaborative infrastructure for research sharing, a preclinical consortium has been organized that will operate in a manner analogous to a clinical trial network. This infrastructure has been named CAESAR (Consortium for preclinicAl assESsment of cARdioprotective therapies). Under the direction of Roberto Bolli, 4 Institutions (University of Louisville, Johns Hopkins, Emory University, and Medical College of Virginia) will work together to conduct blinded, randomized, and adequately powered studies using a rigorous design, dose-response analyses, optimal statistical methods, independent data analysis Cores, an independent statistical Core, verification of tetrazolium data with histology and plasma

  16. Selection of animal models for pre-clinical strategies in evaluating the fracture healing, bone graft substitutes and bone tissue regeneration and engineering.

    PubMed

    Bigham-Sadegh, Amin; Oryan, Ahmad

    2015-06-01

    In vitro assays can be useful in determining biological mechanism and optimizing scaffold parameters, however translation of the in vitro results to clinics is generally hard. Animal experimentation is a better approximation than in vitro tests, and usage of animal models is often essential in extrapolating the experimental results and translating the information in a human clinical setting. In addition, usage of animal models to study fracture healing is useful to answer questions related to the most effective method to treat humans. There are several factors that should be considered when selecting an animal model. These include availability of the animal, cost, ease of handling and care, size of the animal, acceptability to society, resistance to surgery, infection and disease, biological properties analogous to humans, bone structure and composition, as well as bone modeling and remodeling characteristics. Animal experiments on bone healing have been conducted on small and large animals, including mice, rats, rabbits, dogs, pigs, goats and sheep. This review also describes the molecular events during various steps of fracture healing and explains different means of fracture healing evaluation including biomechanical, histopathological and radiological assessments.

  17. Spinal Cord Tolerance in the Age of Spinal Radiosurgery: Lessons From Preclinical Studies

    SciTech Connect

    Medin, Paul M.; Boike, Thomas P.

    2011-04-01

    Clinical implementation of spinal radiosurgery has increased rapidly in recent years, but little is known regarding human spinal cord tolerance to single-fraction irradiation. In contrast, preclinical studies in single-fraction spinal cord tolerance have been ongoing since the 1970s. The influences of field length, dose rate, inhomogeneous dose distributions, and reirradiation have all been investigated. This review summarizes literature regarding single-fraction spinal cord tolerance in preclinical models with an emphasis on practical clinical significance. The outcomes of studies that incorporate uniform irradiation are surprisingly consistent among multiple small- and large-animal models. Extensive investigation of inhomogeneous dose distributions in the rat has demonstrated a significant dose-volume effect while preliminary results from one pig study are contradictory. Preclinical spinal cord dose-volume studies indicate that dose distribution is more critical than the volume irradiated suggesting that neither dose-volume histogram analysis nor absolute volume constraints are effective in predicting complications. Reirradiation data are sparse, but results from guinea pig, rat, and pig studies are consistent with the hypothesis that the spinal cord possesses a large capacity for repair. The mechanisms behind the phenomena observed in spinal cord studies are not readily explained and the ability of dose response models to predict outcomes is variable underscoring the need for further investigation. Animal studies provide insight into the phenomena and mechanisms of radiosensitivity but the true significance of animal studies can only be discovered through clinical trials.

  18. Iron Deprivations Treatment of Breast Cancer: Pre-Clinical Studies

    DTIC Science & Technology

    1997-01-01

    DNA fragmentation analysis and propidium iodide staining. Electron microscopic studies provided additional confirmation of apoptotic cell death. The... DNA fragmentation analysis. Cells grown in transferrin medium were harvested by low-speed centrifugation, washed twice with the basic medium and seeded...the cells grew at a rate similar to that of the control cells. Induced cell death is associated with DNA fragmentation . To evaluate the development of

  19. Preclinical studies of indapamide, a new 2-methylindoline antihypertensive diuretic

    SciTech Connect

    Pruss, T.; Wolf, P.S.

    1983-07-01

    Indapamide is a new indoline antihypertensive diuretic agent whose chemical structure differs substantially from those of the thiazides. The hydrophobic indoline moiety of indapamide confers a lipid solubility to the molecule that is 5 to 80 times greater than that of the thiazide diuretics. Thus indapamide accumulates in vascular smooth muscle at a concentration 10 times higher than that of protein-free perfusate. The affinity of indapamide for vascular smooth muscle manifests itself in vitro and in vivo as a decrease in reactivity following various pharmacologic interventions. Moreover, in vitro studies have demonstrated that indapamide decreases the inward calcium current and the transmembrane influx of calcium. The diuretic effect of indapamide is predominantly due to inhibition of sodium reabsorption at the cortical diluting segment of the distal convoluted tubule. In animal studies, intravenous indapamide has no effect on glomerular filtration rate or renal blood flow. Indapamide is well absorbed and extensively metabolized in animals and humans, with biliary excretion being the predominant route of elimination in animals. Most important, repeat administration of indapamide to dogs with both kidneys removed produces no accumulation of intact indapamide or its metabolites. Extensive drug safety studies in animals indicate that indapamide produces no overt toxicity and exhibits a good margin of safety.

  20. Reporting of preclinical tumor-graft cancer therapeutic studies.

    PubMed

    Sugar, Elizabeth; Pascoe, Adam J; Azad, Nilofer

    2012-11-01

    Characterize the parameters of reporting tumor-graft experiments for oncologic drug development. Using Institute of Scientific Information impact factors, we identified the most-cited medical and oncology journals with tumor-graft experiments in murine models. For each article, the characteristics of the experimental design, outcome measurements, and statistical analysis were examined. We examined 145 articles describing tumor-graft experiments from October through December 2008. The articles spanned a range of disease types, animal models, treatments and delivery methods. One hundred (69%) articles were missing information needed to replicate the experiments. Outcome measurements included: tumor size (83%), biological changes (57%), and survival or cure-rate outcomes (28%). Thirty-three percent did not specify how tumor size was measured and 30% were missing the formula for evaluating volume. Only 14% utilized appropriate statistical methods. Ninety-one percent of studies were reported as positive and 7% reported with mixed positive-negative results; only 2% of studies were reported negative or inconclusive. Twenty-two articles from 2012 showed improvement in the utilization of statistical methods (35% optimal, p = 0.05) but had a similar fraction with experimental design issues (82%; p = 0.32) limiting reproducibility and 91% had positive results. Tumor-graft studies are reported without a set standard, often without the methodological information necessary to reproduce the experiments. The high percentage of positive trials suggests possible publication bias. Considering the widespread use of such experiments for oncologic drug development, scientists and publishers should develop experimental and publication guidelines for such experiments to ensure continued improvements in reporting.

  1. From Bench to Bedside: Lessons Learned in Translating Preclinical Studies in Cancer Drug Development

    PubMed Central

    2013-01-01

    The development of targeted agents in oncology has rapidly expanded over the past 2 decades and has led to clinically significant improvements in the treatment of numerous cancers. Unfortunately, not all success at the bench in preclinical experiments has translated to success at the bedside. As preclinical studies shift toward defining proof of mechanism, patient selection, and rational drug combinations, it is critical to understand the lessons learned from prior translational studies to gain an understanding of prior drug development successes and failures. By learning from prior drug development, future translational studies will provide more clinically relevant data, and the underlying hope is that the clinical success rate will improve and the treatment of patients with ineffective targeted therapy will be limited. PMID:24052618

  2. Preclinical Pharmacokinetics Study of R- and S-Enantiomers of the Histone Deacetylase Inhibitor, AR-42 (NSC 731438), in Rodents.

    PubMed

    Cheng, Hao; Xie, Zhiliang; Jones, William P; Wei, Xiaohui Tracey; Liu, Zhongfa; Wang, Dasheng; Kulp, Samuel K; Wang, Jiang; Coss, Christopher C; Chen, Ching-Shih; Marcucci, Guido; Garzon, Ramiro; Covey, Joseph M; Phelps, Mitch A; Chan, Kenneth K

    2016-05-01

    AR-42, a new orally bioavailable, potent, hydroxamate-tethered phenylbutyrate class I/IIB histone deacetylase inhibitor currently is under evaluation in phase 1 and 2 clinical trials and has demonstrated activity in both hematologic and solid tumor malignancies. This report focuses on the preclinical characterization of the pharmacokinetics of AR-42 in mice and rats. A high-performance liquid chromatography-tandem mass spectrometry assay has been developed and applied to the pharmacokinetic study of the more active stereoisomer, S-AR-42, when administered via intravenous and oral routes in rodents, including plasma, bone marrow, and spleen pharmacokinetics (PK) in CD2F1 mice and plasma PK in F344 rats. Oral bioavailability was estimated to be 26 and 100% in mice and rats, respectively. R-AR-42 was also evaluated intravenously in rats and was shown to display different pharmacokinetics with a much shorter terminal half-life compared to that of S-AR-42. Renal clearance was a minor elimination pathway for parental S-AR-42. Oral administration of S-AR-42 to tumor-bearing mice demonstrated high uptake and exposure of the parent drug in the lymphoid tissues, spleen, and bone marrow. This is the first report of the pharmacokinetics of this novel agent, which is now in early phase clinical trials.

  3. Preclinical and Clinical Studies for Sodium Tungstate: Application in Humans.

    PubMed

    Bertinat, Romina; Nualart, Francisco; Li, Xuhang; Yáñez, Alejandro J; Gomis, Ramón

    2015-02-01

    Diabetes is a complex metabolic disorder triggered by the deficient secretion of insulin by the pancreatic β-cell or the resistance of peripheral tissues to the action of the hormone. Chronic hyperglycemia is the major consequence of this failure, and also the main cause of diabetic problems. Indeed, several clinical trials have agreed in that tight glycemic control is the best way to stop progression of the disease. Many anti-diabetic drugs for treatment of type 2 diabetes are commercially available, but no ideal normoglycemic agent has been developed yet. Moreover, weight gain is the most common side effect of many oral anti-diabetic agents and insulin, and increased weight has been shown to worsen glycemic control and increase the risk of diabetes progression. In this sense, the inorganic salt sodium tungstate (NaW) has been studied in different animal models of metabolic syndrome and diabetes, proving to have a potent effect on normalizing blood glucose levels and reducing body weight, without any hypoglycemic action. Although the liver has been studied as the main site of NaW action, positive effects have been also addressed in muscle, pancreas, brain, adipose tissue and intestine, explaining the effective anti-diabetic action of this salt. Here, we review NaW research to date in these different target organs. We believe that NaW deserves more attention, since all available anti-diabetic treatments remain suboptimal and new therapeutics are urgently needed.

  4. Preclinical and Clinical Studies for Sodium Tungstate: Application in Humans

    PubMed Central

    Bertinat, Romina; Nualart, Francisco; Li, Xuhang; Yáñez, Alejandro J.; Gomis, Ramón

    2015-01-01

    Diabetes is a complex metabolic disorder triggered by the deficient secretion of insulin by the pancreatic β-cell or the resistance of peripheral tissues to the action of the hormone. Chronic hyperglycemia is the major consequence of this failure, and also the main cause of diabetic problems. Indeed, several clinical trials have agreed in that tight glycemic control is the best way to stop progression of the disease. Many anti-diabetic drugs for treatment of type 2 diabetes are commercially available, but no ideal normoglycemic agent has been developed yet. Moreover, weight gain is the most common side effect of many oral anti-diabetic agents and insulin, and increased weight has been shown to worsen glycemic control and increase the risk of diabetes progression. In this sense, the inorganic salt sodium tungstate (NaW) has been studied in different animal models of metabolic syndrome and diabetes, proving to have a potent effect on normalizing blood glucose levels and reducing body weight, without any hypoglycemic action. Although the liver has been studied as the main site of NaW action, positive effects have been also addressed in muscle, pancreas, brain, adipose tissue and intestine, explaining the effective anti-diabetic action of this salt. Here, we review NaW research to date in these different target organs. We believe that NaW deserves more attention, since all available anti-diabetic treatments remain suboptimal and new therapeutics are urgently needed. PMID:25995968

  5. Antiobesity Effects of Anthocyanins in Preclinical and Clinical Studies

    PubMed Central

    Giacometti, Jasminka

    2017-01-01

    The natural phytochemicals present in foods, including anthocyanins, might play a role in attenuating obesity by producing a decrease in weight and adipose tissue. This review focused on current knowledge about anthocyanins' role in obesity and its related comorbidities reported in animal models and humans. We summarized their target identification and mechanism of action through several pathways and their final effects on health and well-being. Into consideration of ongoing researches, we highlighted the following key points: a healthy relationship between anthocyanin supplementation and antiobesity effects suffers of the same pros and cons evidenced when the beneficial responses to other phytochemical treatments towards different degenerative diseases have been considered; the different dosage applied in animal versus clinical studies; the complex metabolism and biotransformation to which anthocyanins and phytochemicals are subjected in the intestine and tissues; the possibility that different components present in the supplemented mixtures can interact generating antagonistic, synergistic, or additive effects difficult to predict, and the difference between prevention and therapy. The evolution of the field must seriously consider the need to establish new and adequate cellular and animal models which may, in turn, allow the design of more efficient and prevention-targeted clinical studies. PMID:28785373

  6. Luciferase fragment complementation imaging in preclinical cancer studies

    PubMed Central

    Lake, Madryn C.; Aboagye, Eric O.

    2014-01-01

    The luciferase fragment complementation assay (LFCA) enables molecular events to be non-invasively imaged in live cells in vitro and in vivo in a comparatively cheap and safe manner. It is a development of previous enzyme complementation assays in which reporter genes are split into two, individually enzymatically inactive, fragments that are able to complement one another upon interaction. This complementation can be used to externally visualize cellular activities. In recent years, the number of studies which have used LFCAs to probe questions relevant to cancer have increased, and this review summarizes the most significant and interesting of these. In particular, it focuses on work conducted on the epidermal growth factor, nuclear and chemokine receptor families, and intracellular signaling pathways, including IP3, cAMP, Akt, cMyc, NRF2 and Rho GTPases. LFCAs which have been developed to image DNA methylation and detect RNA transcripts are also discussed. PMID:25594026

  7. Cocoa Diet and Antibody Immune Response in Preclinical Studies

    PubMed Central

    Camps-Bossacoma, Mariona; Massot-Cladera, Malen; Abril-Gil, Mar; Franch, Angels; Pérez-Cano, Francisco J.; Castell, Margarida

    2017-01-01

    The ability of cocoa to interact with the immune system in vitro and in vivo has been described. In the latter context, a cocoa-enriched diet in healthy rats was able to modify the immune system’s functionality. This fact could be observed in the composition and functionality of lymphoid tissues, such as the thymus, spleen, and lymph nodes. Consequently, immune effector mechanisms, such as antibody synthesis, were modified. A cocoa-enriched diet in young rats was able to attenuate the serum levels of immunoglobulin (Ig) G, IgM, and IgA and also the intestinal IgM and IgA secretion. Moreover, in immunized rats, the intake of cocoa decreased specific IgG1, IgG2a, IgG2c, and IgM concentrations in serum. This immune-regulator potential was then tested in disease models in which antibodies play a pathogenic role. A cocoa-enriched diet was able to partially prevent the synthesis of autoantibodies in a model of autoimmune arthritis in rats and was also able to protect against IgE and T helper 2-related antibody synthesis in two rat models of allergy. Likewise, a cocoa-enriched diet prevented an oral sensitization process in young rats. In this review, we will focus on the influence of cocoa on the acquired branch of the immune function. Therefore, we will focus on how a cocoa diet influences lymphocyte function both in the systemic and intestinal immune system. Likewise, its potential role in preventing some antibody-induced immune diseases is also included. Although further studies must characterize the particular cocoa components responsible for such effects and nutritional studies in humans need to be carried out, cocoa has potential as a nutraceutical agent in some hypersensitivity status. PMID:28702458

  8. Flii neutralizing antibodies improve wound healing in porcine preclinical studies.

    PubMed

    Jackson, Jessica E; Kopecki, Zlatko; Adams, Damian H; Cowin, Allison J

    2012-01-01

    Wound healing is an important area of widely unmet medical need, with millions of procedures carried out worldwide which could potentially benefit from a product to improve the wound repair process. Our studies investigating the actin-remodeling protein Flightless I (Flii) show it to be an important regulator of wound healing. Flii-deficient mice have enhanced wound healing in comparison to Flii overexpressing mice which have impaired wound healing. For the first time, we show that a Flightless I neutralizing monoclonal antibody (FnAb) therapy is effective in a large animal model of wound repair. Porcine 5 cm incisional and 6.25 cm(2) excisional wounds were treated with FnAb at the time of wounding and for two subsequent days. The wounds were dressed in Tegaderm dressings and left to heal by secondary intention for 7 and 35 days, respectively. At the relevant end points, the wounds were excised and processed for histological analysis. Parameters of wound area, collagen deposition, and scar appearance were analyzed. The results show that treatment with FnAb accelerates reepithelialization and improves the macroscopic appearance of early scars. FnAbs have the potential to enhance wound repair and reduce scar formation. © 2012 by the Wound Healing Society.

  9. Analgesic and hypnotic activities of Laghupanchamula: A preclinical study

    PubMed Central

    Ghildiyal, Shivani; Gautam, Manish K.; Joshi, Vinod K.; Goel, Raj K.

    2014-01-01

    Background: In Ayurvedic classics, two types of Laghupanchamula -five plant roots (LP) have been mentioned containing four common plants viz. Kantakari, Brihati, Shalaparni, and Prinshniparni and the fifth plant is either Gokshura (LPG) or Eranda (LPE). LP has been documented to have Shothahara (anti-inflammatory), Shulanashka (analgesic), Jvarahara (antipyretic), and Rasayana (rejuvenator) activities. Aim: To evaluate the acute toxicity (in mice), analgesic and hypnotic activity (in rats) of 50% ethanolic extract of LPG (LPGE) and LPE (LPEE). Materials and Methods: LPEG and LPEE were prepared separately by using 50% ethanol following the standard procedures. A graded dose (250, 500 and 1000 mg/kg) response study for both LPEE and LPGE was carried out for analgesic activity against rat tail flick response which indicated 500 mg/kg as the optimal effective analgesic dose. Hence, 500 mg/kg dose of LPEE and LPGE was used for hot plate test and acetic acid induced writhing model in analgesic activity and for evaluation of hypnotic activity. Results: Both the extracts did not produce any acute toxicity in mice at single oral dose of 2.0 g/kg. Both LPGE and LPEE (250, 500, and 1000 mg/kg) showed dose-dependent elevation in pain threshold and peak analgesic effect at 60 min as evidenced by increased latency period in tail-flick method by 25.1-62.4% and 38.2-79.0% respectively. LPGE and LPEE (500 mg/kg) increased reaction time in hot-plate test at peak 60 min analgesic effect by 63.2 and 85.8% and reduction in the number of acetic acid-induced writhes by 55.9 and 65.8% respectively. Both potentiated pentobarbitone-induced hypnosis as indicated by increased duration of sleep in treated rats. Conclusion: The analgesic and hypnotic effects of LP formulations authenticate their uses in Ayurvedic system of Medicine for painful conditions. PMID:25364205

  10. Photodynamic diagnosis of ovarian cancer using hexaminolaevulinate: a preclinical study.

    PubMed

    Lüdicke, F; Gabrecht, T; Lange, N; Wagnières, G; Van Den Bergh, H; Berclaz, L; Major, A L

    2003-06-02

    The unfailing detection of micrometastases during surgery of patients suffering from ovarian cancer is mandatory for the optimal management of this disease. Thus, the present study aimed at determining the feasibility of detecting micrometastases in an ovarian cancer model using the intraperitoneal administration of the photosensitiser precursor hexaminolaevulinate (HAL). For this purpose, HAL was applied intraperitoneally at different concentrations (4-12 mM) to immunocompetent Fischer 344 rats bearing a syngeneic epithelial ovarian carcinoma. The tumours were visualised laparoscopically using both white and blue light (D-light, Karl Storz, Tuttlingen, Germany), and the number of peritoneal micrometastases detected through HAL-induced photodiagnosis (PD) was compared to standard white light visualisation. Fluorescence spectra were recorded with an optical fibre-based spectrofluorometer and the fluorescence intensities were compared to the protoporphyrin IX (PpIX) fluorescence induced by 5-aminolevulinic acid under similar conditions. The number of metastases detected by the PD blue light mode was higher than when using standard white light abdominal inspection for all applied concentrations. Twice as many cancer lesions were detected by fluorescence than by white light inspection. The hexyl-ester derivative produced higher PpIX fluorescence than its parent substance aminolevulinic acid at the same concentration and application time. Fluorescence contrast between healthy and cancerous tissue was excellent for both compounds. To overcome poor diagnostic efficiency and to detect peritoneal ovarian carcinoma foci in the large surface area of the human peritoneal cavity, HAL fluorescence-based visualisation techniques may acquire importance in future and lead to a more correct staging of early ovarian cancer.

  11. Endpoint measures in the mdx mouse relevant for muscular dystrophy pre-clinical studies

    PubMed Central

    Kobayashi, Yvonne M.; Rader, Erik P.; Crawford, Robert W.; Campbell, Kevin P.

    2011-01-01

    Loss of mobility influences the quality of life for patients with neuromuscular diseases. Common measures of mobility and chronic muscle damage are the six-minute walk test and serum creatine kinase. Despite extensive pre-clinical studies of therapeutic approaches, characterization of these measures is incomplete. To address this, a six-minute ambulation assay, serum creatine kinase, and myoglobinuria were investigated for the mdx mouse, a dystrophinopathy mouse model commonly used in pre-clinical studies. Mdx mice ambulated shorter distances than normal controls, a disparity accentuated after mild exercise. An asymmetric pathophysiology in mdx mice was unmasked with exercise, and peak measurements of serum creatine kinase and myoglobinuria were identified. Our data highlights the necessity to consider asymmetric pathology and timing of biomarkers when testing potential therapies for muscular dystrophy. PMID:22154712

  12. Preclinical studies of 5-fluoro-2'-deoxycytidine and tetrahydrouridine in pediatric brain tumors.

    PubMed

    Morfouace, Marie; Nimmervoll, Birgit; Boulos, Nidal; Patel, Yogesh T; Shelat, Anang; Freeman, Burgess B; Robinson, Giles W; Wright, Karen; Gajjar, Amar; Stewart, Clinton F; Gilbertson, Richard J; Roussel, Martine F

    2016-01-01

    Chemotherapies active in preclinical studies frequently fail in the clinic due to lack of efficacy, which limits progress for rare cancers since only small numbers of patients are available for clinical trials. Thus, a preclinical drug development pipeline was developed to prioritize potentially active regimens for pediatric brain tumors spanning from in vitro drug screening, through intracranial and intra-tumoral pharmacokinetics to in vivo efficacy studies. Here, as an example of the pipeline, data are presented for the combination of 5-fluoro-2'-deoxycytidine and tetrahydrouridine in three pediatric brain tumor models. The in vitro activity of nine novel therapies was tested against tumor spheres derived from faithful mouse models of Group 3 medulloblastoma, ependymoma, and choroid plexus carcinoma. Agents with the greatest in vitro potency were then subjected to a comprehensive series of in vivo pharmacokinetic (PK) and pharmacodynamic (PD) studies culminating in preclinical efficacy trials in mice harboring brain tumors. The nucleoside analog 5-fluoro-2'-deoxycytidine (FdCyd) markedly reduced the proliferation in vitro of all three brain tumor cell types at nanomolar concentrations. Detailed intracranial PK studies confirmed that systemically administered FdCyd exceeded concentrations in brain tumors necessary to inhibit tumor cell proliferation, but no tumor displayed a significant in vivo therapeutic response. Despite promising in vitro activity and in vivo PK properties, FdCyd is unlikely to be an effective treatment of pediatric brain tumors, and therefore was deprioritized for the clinic. Our comprehensive and integrated preclinical drug development pipeline should reduce the attrition of drugs in clinical trials.

  13. 7α-Methyl-19-Nortestosterone (MENT) vs. Testosterone Implants for Hypogonadal Osteoporosis: a Preclinical Study in the Aged Male Orchidectomized Rat Model

    PubMed Central

    Sinnesael, Mieke; Callewaert, Filip; Morreels, Maarten; Kumar, Narender; Sitruk-Ware, Regine; Van Proeyen, Karen; Hespel, Peter; Boonen, Steven; Claessens, Frank; Vanderschueren, Dirk

    2011-01-01

    Purpose Overt male hypogonadism induces not only osteoporosis but also unfavorable changes in body composition, which can be prevented by testosterone (T) replacement. In this preclinical study, the potential of synthetic androgen 7α-methyl-19-nortestosterone (MENT) as alternative treatment for male hypogonadism was evaluated in comparison with T. Methods 11-month-old male rats were orchidectomized (orch) and left untreated for 2-months. Subsequently, the effects of 4-months MENT (12 µg/day) and T (72µg/day) treatment on bone, muscle and fat were analyzed by microcomputed tomography, dual-energy X-ray absorptiometry, dynamic bone histomorphometry and muscle fiber typing. Results At the onset of treatment orch rats were clearly hypogonadal. This was evidenced by significant reductions of androgen-sensitive organ weight, lean mass, cortical thickness and trabecular bone volume compared with sham-operated aged-matched controls (sham). MENT and T restored weight of androgen-sensitive organs to a similar extent, with a superior anabolic action of MENT on levator ani muscle. Both androgens not only fully rescued hypogonadal loss of lean mass, but also restored muscle fiber type composition and trabecular bone volume. Cortical bone loss was similarly prevented by MENT and T, but without full recovery to sham. Both androgens stimulated periosteal bone formation, but with a stronger effect of T. In contrast, MENT more strongly suppressed endocortical bone formation and bone turnover rate and reduced fat mass and serum leptin to a greater extent than T. Conclusion MENT and T are both effective replacement therapies to stimulate bone and muscle in hypogonadal rats, with stronger lipolytic action of MENT. PMID:21790658

  14. 7α-methyl-19-nortestosterone vs. testosterone implants for hypogonadal osteoporosis: a preclinical study in the aged male orchidectomized rat model.

    PubMed

    Sinnesael, M; Callewaert, F; Morreels, M; Kumar, N; Sitruk-Ware, R; Van Proeyen, K; Hespel, P; Boonen, S; Claessens, F; Vanderschueren, D

    2011-12-01

    Overt male hypogonadism induces not only osteoporosis but also unfavourable changes in body composition, which can be prevented by testosterone (T) replacement. In this preclinical study, the potential of synthetic androgen 7α-methyl-19-nortestosterone (MENT) as alternative treatment for male hypogonadism was evaluated in comparison with T. Eleven-month-old male rats were orchidectomized (orch) and left untreated for 2-months. Subsequently, the effects of 4-month MENT (12 μg/day) and T (72 μg/day) treatment on bone, muscle and fat were analysed using microcomputed tomography, dual-energy X-ray absorptiometry, dynamic bone histomorphometry and muscle fibre typing. At the onset of treatment, orch rats were clearly hypogonadal. This was evidenced by significant reductions of androgen-sensitive organ weight, lean mass, cortical thickness and trabecular bone volume compared with sham-operated aged-matched controls (sham). MENT and T restored weight of androgen-sensitive organs to a similar extent, with a superior anabolic action of MENT on levator ani muscle. Both androgens not only fully rescued hypogonadal loss of lean mass but also restored muscle fibre type composition and trabecular bone volume. Cortical bone loss was similarly prevented by MENT and T, but without full recovery to sham. Both androgens stimulated periosteal bone formation, but with a stronger effect of T. By contrast, MENT more strongly suppressed endocortical bone formation and bone turnover rate and reduced fat mass and serum leptin to a greater extent than T. MENT and T are both effective replacement therapies to stimulate bone and muscle in hypogonadal rats, with stronger lipolytic action of MENT.

  15. Pediatric Autoimmune Disorders Associated with Streptococcal Infections and Tourette's Syndrome in Preclinical Studies

    PubMed Central

    Spinello, Chiara; Laviola, Giovanni; Macrì, Simone

    2016-01-01

    Accumulating evidence suggests that Tourette's Syndrome (TS) – a multifactorial pediatric disorder characterized by the recurrent exhibition of motor tics and/or vocal utterances – can partly depend on immune dysregulation provoked by early repeated streptococcal infections. The natural and adaptive antibody-mediated reaction to streptococcus has been proposed to potentially turn into a pathological autoimmune response in vulnerable individuals. Specifically, in conditions of increased permeability of the blood brain barrier (BBB), streptococcus-induced antibodies have been proposed to: (i) reach neuronal targets located in brain areas responsible for motion control; and (ii) contribute to the exhibition of symptoms. This theoretical framework is supported by indirect evidence indicating that a subset of TS patients exhibit elevated streptococcal antibody titers upon tic relapses. A systematic evaluation of this hypothesis entails preclinical studies providing a proof of concept of the aforementioned pathological sequelae. These studies shall rest upon individuals characterized by a vulnerable immune system, repeatedly exposed to streptococcus, and carefully screened for phenotypes isomorphic to the pathological signs of TS observed in patients. Preclinical animal models may thus constitute an informative, useful tool upon which conducting targeted, hypothesis-driven experiments. In the present review we discuss the available evidence in preclinical models in support of the link between TS and pediatric autoimmune neuropsychiatric disorders associated with streptococcus infections (PANDAS), and the existing gaps that future research shall bridge. Specifically, we report recent preclinical evidence indicating that the immune responses to repeated streptococcal immunizations relate to the occurrence of behavioral and neurological phenotypes reminiscent of TS. By the same token, we discuss the limitations of these studies: limited evidence of behavioral phenotypes

  16. Pre-clinical Models for Oral and Periodontal Reconstructive Therapies

    PubMed Central

    Pellegrini, G.; Seol, Y.J.; Gruber, R.; Giannobile, W.V.

    2009-01-01

    The development of new medical formulations (NMF) for reconstructive therapies has considerably improved the available treatment options for individuals requiring periodontal repair or oral implant rehabilitation. Progress in tissue engineering and regenerative medicine modalities strongly depends on validated pre-clinical research. Pre-clinical testing has contributed to the recent approval of NMF such as GEM 21S® and INFUSE® bone grafts for periodontal and oral regenerative therapies. However, the selection of a suitable pre-clinical model for evaluation of the safety and efficacy of a NMF remains a challenge. This review is designed to serve as a primer to choose the appropriate pre-clinical models for the evaluation of NMF in situations requiring periodontal or oral reconstruction. Here, we summarize commonly used pre-clinical models and provide examples of screening and functional studies of NMF that can be translated into clinical use. PMID:19887682

  17. Preclinical studies on specific gene therapy for recessive retinal degenerative diseases.

    PubMed

    Stieger, Knut; Chauveau, Christine; Rolling, Fabienne

    2010-10-01

    Inherited retinal diseases are non-lethal and have a wide level of genetic heterogeneity. Many of the genes involved have now been identified and their function elucidated, providing a major step towards the development of gene-based treatments. The most widely used vectors for ocular gene delivery are based on adeno-associated virus (AAV) because they mediate long-term transgene expression in a variety of retinal cell types and elicit minimal immune responses. Extensive preclinical evaluation of gene transfer strategies in small and large animal models is key to the development of successful gene-based therapies for the retina. These preclinical studies have already allowed the field to reach the point where gene therapy to treat inherited blindness has been brought to clinical trial. In this manuscript, we focus on recombinant AAV-mediated specific gene therapy for recessive retinal degenerative diseases we describe the preclinical studies for the treatment of retinal degeneration caused by retinal pigmented epithelium (RPE) cells or photoreceptor defects and the immune response induced by retinal rAAV gene transfer.

  18. Ethical challenges in preclinical Alzheimer's disease observational studies and trials: Results of the Barcelona summit.

    PubMed

    Molinuevo, José L; Cami, Jordi; Carné, Xavier; Carrillo, Maria C; Georges, Jean; Isaac, Maria B; Khachaturian, Zaven; Kim, Scott Y H; Morris, John C; Pasquier, Florence; Ritchie, Craig; Sperling, Reisa; Karlawish, Jason

    2016-05-01

    Alzheimer's disease (AD) is among the most significant health care burdens. Disappointing results from clinical trials in late-stage AD persons combined with hopeful results from trials in persons with early-stage suggest that research in the preclinical stage of AD is necessary to define an optimal therapeutic success window. We review the justification for conducting trials in the preclinical stage and highlight novel ethical challenges that arise and are related to determining appropriate risk-benefit ratios and disclosing individuals' biomarker status. We propose that to conduct clinical trials with these participants, we need to improve public understanding of AD using unified vocabulary, resolve the acceptable risk-benefit ratio in asymptomatic participants, and disclose or not biomarker status with attention to study type (observational studies vs clinical trials). Overcoming these challenges will justify clinical trials in preclinical AD at the societal level and aid to the development of societal and legal support for trial participants. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Detection of Alzheimer's disease and dementia in the preclinical phase: population based cohort study

    PubMed Central

    Palmer, Katie; Bäckman, Lars; Winblad, Bengt; Fratiglioni, Laura

    2003-01-01

    Objectives To evaluate a simple three step procedure to identify people in the general population who are in the preclinical phase of Alzheimer's disease and dementia. Design Three year population based cohort study. Setting Kungsholmen cohort, Stockholm, Sweden. Participants 1435 people aged 75-95 years without dementia. Assessments Single question asking about memory complaints, assessment by mini-mental state examination, and neuropsychological testing. Main outcome measure Alzheimer's disease and dementia at three year follow up. Results None of the three instruments was sufficiently predictive of Alzheimer's disease and dementia when administered separately. After participants had been screened for memory complaints and global cognitive impairment, specific tests of word recall and verbal fluency had positive predictive values for dementia of 85-100% (95% confidence intervals range from 62% to 100%). However, only 18% of future dementia cases were identified in the preclinical phase by this three step procedure. Memory complaints were the most sensitive indicator of Alzheimer's disease and dementia in the whole population, but only half the future dementia cases reported memory problems three years before diagnosis. Conclusion This three step procedure, which simulates what might occur in clinical practice, has a high positive predictive value for dementia, although only a small number of future cases can be identified. What is already known on this topicAlzheimer's disease is characterised by a preclinical phase, during which cognitive deficits are seen before diagnosisElderly people with subjective memory complaints and objective global cognitive impairment have a high risk of developing Alzheimer's disease and dementiaWhat this study addsThis three step procedure (self report of memory complaints, test of global cognitive functioning, and then domain specific cognitive tests) has a positive predictivity of 85-100% for Alzheimer's disease and dementia at

  20. Amyloid-β, anxiety, and cognitive decline in preclinical Alzheimer disease: a multicenter, prospective cohort study.

    PubMed

    Pietrzak, Robert H; Lim, Yen Ying; Neumeister, Alexander; Ames, David; Ellis, Kathryn A; Harrington, Karra; Lautenschlager, Nicola T; Restrepo, Carolina; Martins, Ralph N; Masters, Colin L; Villemagne, Victor L; Rowe, Christopher C; Maruff, Paul

    2015-03-01

    Alzheimer disease (AD) is now known to have a long preclinical phase in which pathophysiologic processes develop many years, even decades, before the onset of clinical symptoms. Although the presence of abnormal levels of amyloid-β (Aβ) is associated with higher rates of progression to clinically classified mild cognitive impairment or dementia, little research has evaluated potentially modifiable moderators of Aβ-related cognitive decline, such as anxiety and depressive symptoms. To evaluate the association between Aβ status and cognitive changes, and the role of anxiety and depressive symptoms in moderating Aβ-related cognitive changes in the preclinical phase of AD. In this multicenter, prospective cohort study with baseline and 18-, 36-, and 54-month follow-up assessments, we studied 333 healthy, older adults at hospital-based research clinics. Carbon 11-labeled Pittsburgh Compound B (PiB)-, florbetapir F 18-, or flutemetamol F 18-derived measures of Aβ, Hospital Anxiety and Depression Scale scores, and comprehensive neuropsychological evaluation that yielded measures of global cognition, verbal memory, visual memory, attention, language, executive function, and visuospatial ability. A positive Aβ (Aβ+) status at baseline was associated with a significant decline in global cognition, verbal memory, language, and executive function, and elevated anxiety symptoms moderated these associations. Compared with the Aβ+, low-anxiety group, slopes of cognitive decline were significantly more pronounced in the Aβ+, high-anxiety group, with Cohen d values of 0.78 (95% CI, 0.33-1.23) for global cognition, 0.54 (95% CI, 0.10-0.98) for verbal memory, 0.51 (95% CI, 0.07-0.96) for language, and 0.39 (95% CI, 0.05-0.83) for executive function. These effects were independent of age, educational level, IQ, APOE genotype, subjective memory complaints, vascular risk factors, and depressive symptoms; furthermore, depressive symptoms and subjective memory complaints did not

  1. Accelerating drug discovery for Alzheimer's disease: best practices for preclinical animal studies.

    PubMed

    Shineman, Diana W; Basi, Guriqbal S; Bizon, Jennifer L; Colton, Carol A; Greenberg, Barry D; Hollister, Beth A; Lincecum, John; Leblanc, Gabrielle G; Lee, Linda Bobbi H; Luo, Feng; Morgan, Dave; Morse, Iva; Refolo, Lorenzo M; Riddell, David R; Scearce-Levie, Kimberly; Sweeney, Patrick; Yrjänheikki, Juha; Fillit, Howard M

    2011-09-28

    Animal models have contributed significantly to our understanding of the underlying biological mechanisms of Alzheimer's disease (AD). As a result, over 300 interventions have been investigated and reported to mitigate pathological phenotypes or improve behavior in AD animal models or both. To date, however, very few of these findings have resulted in target validation in humans or successful translation to disease-modifying therapies. Challenges in translating preclinical studies to clinical trials include the inability of animal models to recapitulate the human disease, variations in breeding and colony maintenance, lack of standards in design, conduct and analysis of animal trials, and publication bias due to under-reporting of negative results in the scientific literature. The quality of animal model research on novel therapeutics can be improved by bringing the rigor of human clinical trials to animal studies. Research communities in several disease areas have developed recommendations for the conduct and reporting of preclinical studies in order to increase their validity, reproducibility, and predictive value. To address these issues in the AD community, the Alzheimer's Drug Discovery Foundation partnered with Charles River Discovery Services (Morrisville, NC, USA) and Cerebricon Ltd. (Kuopio, Finland) to convene an expert advisory panel of academic, industry, and government scientists to make recommendations on best practices for animal studies testing investigational AD therapies. The panel produced recommendations regarding the measurement, analysis, and reporting of relevant AD targets, th choice of animal model, quality control measures for breeding and colony maintenance, and preclinical animal study design. Major considerations to incorporate into preclinical study design include a priori hypotheses, pharmacokinetics-pharmacodynamics studies prior to proof-of-concept testing, biomarker measurements, sample size determination, and power analysis. The

  2. Attempted and successful compensation in preclinical and early manifest neurodegeneration - a review of task FMRI studies.

    PubMed

    Scheller, Elisa; Minkova, Lora; Leitner, Mathias; Klöppel, Stefan

    2014-01-01

    Several models of neural compensation in healthy aging have been suggested to explain brain activity that aids to sustain cognitive function. Applying recently suggested criteria of "attempted" and "successful" compensation, we reviewed existing literature on compensatory mechanisms in preclinical Huntington's disease (HD) and amnestic mild cognitive impairment (aMCI). Both disorders constitute early stages of neurodegeneration ideal for examining compensatory mechanisms and developing targeted interventions. We strived to clarify whether compensation criteria derived from healthy aging populations can be applied to early neurodegeneration. To concentrate on the close coupling of cognitive performance and brain activity, we exclusively addressed task fMRI studies. First, we found evidence for parallels in compensatory mechanisms between healthy aging and neurodegenerative disease. Several studies fulfilled criteria of attempted compensation, while reports of successful compensation were largely absent, which made it difficult to conclude on. Second, comparing working memory studies in preclinical HD and aMCI, we identified similar compensatory patterns across neurodegenerative disorders in lateral and medial prefrontal cortex. Such patterns included an inverted U-shaped relationship of neurodegeneration and compensatory activity spanning from preclinical to manifest disease. Due to the lack of studies systematically targeting all criteria of compensation, we propose an exemplary study design, including the manipulation of compensating brain areas by brain stimulation. Furthermore, we delineate the benefits of targeted interventions by non-invasive brain stimulation, as well as of unspecific interventions such as physical activity or cognitive training. Unambiguously detecting compensation in early neurodegenerative disease will help tailor interventions aiming at sustained overall functioning and delayed clinical disease onset.

  3. New bone formation in bone defects after melatonin and porcine bone grafts: experimental study in rabbits.

    PubMed

    Calvo-Guirado, José-Luis; Gómez-Moreno, Gerardo; Maté-Sánchez, José-Eduardo; López-Marí, Laura; Delgado-Ruiz, Rafael; Romanos, Georgios E

    2015-04-01

    The aim of this study was to evaluate the effect of the topical application of melatonin compared with collagenized porcine bone grafts to accelerate bone formation 2 months after their insertion in tibiae rabbits. Twenty New Zealand rabbits weighing 3,900-4,500 g were used. Twenty collagenized porcine bone (MP3) grafts, twenty melatonin-impregnated bone grafts, and twenty control areas were placed in the proximal metaphyseal area of both rear tibias. Four groups were formed according to the moment in which animal killing was carried out: Group I (15 days), Group II (30 days), Group III (45 days) and Group IV (60 days). Cortical width and cortical length of bone formation was measured. Following implantation, an anteroposterior and lateral radiological study was carried out. Samples were sectioned at 5 μm and stained using hematoxylin-Eeosin, Masson's trichromic, and Gordon-Switt reticulin stains. After 60 days of treatment period, melatonin increased the length of cortical bone formation 99.03 ± 0.61% like control 98.90 ± 3.82% compared with porcine bone 92.73 ± 1.08%. Related to perimeter of cortical bone of the tibiae melatonin new bone was 98.35 ± 1.14% like control 98.0 ± 1.43% more than porcine bone 92.05 ± 1.03%. Histomorphometric values related to porcine bone were connective tissue 49.16 ± 2.4%, graft material (MP3) 23.52 ± 2.3%, and new bone formation 27.32 ± 1.4% compared with test group with melatonin 24.5 ± 1.2%, connective tissue 45.1 ± 1.2%, and new bone formation of 30.4 ± 1.0%. Melatonin has proven to regenerate the width and length of cortical bone in tibiae rabbits more quickly than collagenized porcine bone. Melatonin acts as a bone stimulator compared with porcine bone and control sites. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Effect of soy isoflavones on the growth of human breast tumors: findings from preclinical studies

    PubMed Central

    Kwon, Youngjoo

    2014-01-01

    Breast cancer is the most common cancer among women worldwide, and many women with breast cancer live more than 5 years after their diagnosis. Breast cancer patients and survivors have a greater interest in taking soy foods and isoflavone supplements. However, the effect of isoflavones on breast cancer remains controversial. Thus, it is critical to determine if and when isoflavones are beneficial or detrimental to breast cancer patients. According to the available preclinical data, high concentrations of isoflavones inhibit the proliferation of breast cancer cells, regardless of their estrogen receptor (ER) status. In comparison, genistein, a major isoflavone, has stimulated tumor growth at low concentrations and mitigated tamoxifen efficacy in ER-positive breast cancer. Studies have indicated that the relative levels of genistein and estrogen at the target site are important to determine the genistein effect on the ER-positive tumor growth. However, studies using ovariectomized mice and subcutaneous xenograft models might not truly reflect estrogen concentrations in human breast tumors. Moreover, it may be an oversimplification that isoflavones stimulate hormone-dependent tumor growth due to their potential estrogenic effect since studies also suggest nonestrogenic anticancer effects of isoflavones and ER-independent anticancer activity of tamoxifen. Therefore, the concentrations of isoflavones and estrogen in human breast tumors should be considered better in future preclinical studies and the parameters that can estimate those levels in breast tumors are required in human clinical/epidemiological investigation. In addition, it will be important to identify the molecular mechanisms that either inhibit or promote the growth of breast cancer cells by soy isoflavones, and use those molecules to evaluate the relevance of the preclinical findings to the human disease and to predict the health effects of isoflavones in human breast tumors. PMID:25493176

  5. PopED lite: An optimal design software for preclinical pharmacokinetic and pharmacodynamic studies.

    PubMed

    Aoki, Yasunori; Sundqvist, Monika; Hooker, Andrew C; Gennemark, Peter

    2016-04-01

    Optimal experimental design approaches are seldom used in preclinical drug discovery. The objective is to develop an optimal design software tool specifically designed for preclinical applications in order to increase the efficiency of drug discovery in vivo studies. Several realistic experimental design case studies were collected and many preclinical experimental teams were consulted to determine the design goal of the software tool. The tool obtains an optimized experimental design by solving a constrained optimization problem, where each experimental design is evaluated using some function of the Fisher Information Matrix. The software was implemented in C++ using the Qt framework to assure a responsive user-software interaction through a rich graphical user interface, and at the same time, achieving the desired computational speed. In addition, a discrete global optimization algorithm was developed and implemented. The software design goals were simplicity, speed and intuition. Based on these design goals, we have developed the publicly available software PopED lite (http://www.bluetree.me/PopED_lite). Optimization computation was on average, over 14 test problems, 30 times faster in PopED lite compared to an already existing optimal design software tool. PopED lite is now used in real drug discovery projects and a few of these case studies are presented in this paper. PopED lite is designed to be simple, fast and intuitive. Simple, to give many users access to basic optimal design calculations. Fast, to fit a short design-execution cycle and allow interactive experimental design (test one design, discuss proposed design, test another design, etc). Intuitive, so that the input to and output from the software tool can easily be understood by users without knowledge of the theory of optimal design. In this way, PopED lite is highly useful in practice and complements existing tools. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Guidelines for reporting pre-clinical in vitro studies on dental materials.

    PubMed

    Faggion, Clovis Mariano

    2012-12-01

    In vitro pre-clinical research is an important aspect of the development of new dental materials and techniques, because it can provide essential information for further testing of therapeutic approaches in clinical trials. These pre-clinical experiments should therefore be reported with the same rigor as studies involving humans. The objectives of this paper were twofold: (a) to search and assess existing guidelines for reporting in vitro studies in dentistry, and (b) to present a methodology for reporting these studies, based on the CONSORT checklist for reporting randomized clinical trials. After a comprehensive search in PubMed database, no guidelines for reporting in vitro studies in dentistry were found. The proposed methodology is presented and the rationale for the choice of fourteen guidelines for producing the different sections of such papers is described in detail. The assessment of a sample of in vitro studies using the proposed guidelines showed that the standards of reporting should be improved. Good standards of reporting of studies are necessary for improvement of efficiency in dental research. The guidelines presented are the first standards for reporting in vitro studies in dentistry. As with the original CONSORT document, the modified checklist is evolving. It should, therefore, be further tested by researchers and the results of these assessments should be used for further improvement of this tool.

  7. Anticancer Activity of Curcumin and Its Analogues: Preclinical and Clinical Studies.

    PubMed

    Allegra, Alessandro; Innao, Vanessa; Russo, Sabina; Gerace, Demetrio; Alonci, Andrea; Musolino, Caterina

    2017-01-02

    Curcumin has been shown to have a wide variety of therapeutic effects, ranging from anti-inflammatory, chemopreventive, anti-proliferative, and anti-metastatic. This review provides an overview of the recent research conducted to overcome the problems with the bioavailability of curcumin, and of the preclinical and clinical studies that have reported success in combinatorial strategies coupling curcumin with other treatments. Research on the signaling pathways that curcumin treatment targets shows that it potently acts on major intracellular components involved in key processes such as genomic modulations, cell invasion and cell death pathways. Curcumin is a promising molecule for the prevention and treatment of cancer.

  8. Evaluation of a novel high-intensity focused ultrasound device: preclinical studies in a porcine model.

    PubMed

    Jewell, Mark L; Desilets, Charles; Smoller, Bruce R

    2011-05-01

    High-intensity focused ultrasound (HIFU) has been applied clinically for the noninvasive treatment of pathological conditions in various organs for over 50 years; however, there are little data describing the use of thermal HIFU to ablate fat for body contouring and treatment of collagen-rich layers. A novel device under clinical investigation (LipoSonix; Medicis Technologies Corporation, Bothell, Washington) uses HIFU to eliminate unwanted adipose tissue. The authors describe the results of HIFU treatment in a series of preclinical studies performed in a validated porcine model. Preclinical research included in vivo treatment of the abdominal subcutaneous adipose tissue of swine with transcutaneous HIFU therapy. Endpoint analyses included thermocouple temperature data, full-body necropsy, local pathology and histology studies, clinical hematology, urinalysis, and blood chemistry parameters, including lipid panels. The application of HIFU energy levels of 166 to 372 J/cm(2) generated tissue temperature approaching 70°C, which was restricted to the focal area (n = seven). Application of 68 and 86 J/cm(2) did not produce clinically-significant changes in serum liver function tests, free fatty acids, or cholesterol (n = eight). Gross examination of tissue from various organs showed no evidence of fat emboli or accumulation (n = two). Histology demonstrated well-preserved vasculature and intact nerve fibers within the HIFU focal area (n = three). Following treatment with 85.3 to 270 J/cm(2), normal healing response included the migration of macrophages into the damaged tissue and removal of disrupted cellular debris and lipids (n = 8). In a preclinical swine model, the controlled thermal effect of HIFU appears to provide a safe and effective means for ablating subcutaneous adipose tissue.

  9. Plant-based medicines for anxiety disorders, Part 1: a review of preclinical studies.

    PubMed

    Sarris, Jerome; McIntyre, Erica; Camfield, David A

    2013-03-01

    Research in the area of herbal psychopharmacology has revealed a variety of promising medicines that may provide benefit in the treatment of general anxiety and specific anxiety disorders. However, a comprehensive review of plant-based anxiolytics has been absent to date. This article (part 1) reviews herbal medicines for which only preclinical investigations for anxiolytic activity have been performed. In part 2, we review herbal medicines for which there have been clinical investigations for anxiolytic activity. An open-ended, language-restricted (English) search of MEDLINE (PubMed), CINAHL, Scopus and the Cochrane Library databases was conducted (up to 28 October 2012) using specific search criteria to identify herbal medicines that have been investigated for anxiolytic activity. This search of the literature revealed 1,525 papers, from which 53 herbal medicines were included in the full review (having at least one study using the whole plant extract). Of these plants, 21 had human clinical trial evidence (reviewed in part 2), with another 32 having solely preclinical studies (reviewed here in part 1). Preclinical evidence of anxiolytic activity (without human clinical trials) was found for Albizia julibrissin, Sonchus oleraceus, Uncaria rhynchophylla, Stachys lavandulifolia, Cecropia glazioui, Magnolia spp., Eschscholzia californica, Erythrina spp., Annona spp., Rubus brasiliensis, Apocynum venetum, Nauclea latifolia, Equisetum arvense, Tilia spp., Securidaca longepedunculata, Achillea millefolium, Leea indica, Juncus effusus, Coriandrum sativum, Eurycoma longifolia, Turnera diffusa, Euphorbia hirta, Justicia spp., Crocus sativus, Aloysia polystachya, Albies pindrow, Casimiroa edulis, Davilla rugosa, Gastrodia elata, Sphaerathus indicus, Zizyphus jujuba and Panax ginseng. Common mechanisms of action for the majority of botanicals reviewed primarily involve GABA, either via direct receptor binding or ionic channel or cell membrane modulation; GABA transaminase

  10. Food for Thought Look Back in Anger – What Clinical Studies Tell Us About Preclinical Work

    PubMed Central

    Hartung, Thomas

    2013-01-01

    Summary Misled by animal studies and basic research? Whenever we take a closer look at the outcome of clinical trials in a field such as, most recently, stroke or septic shock, we see how limited the value of our preclinical models was. For all indications, 95% of drugs that enter clinical trials do not make it to the market, despite all promise of the (animal) models used to develop them. Drug development has started already to decrease its reliance on animal models: In Europe, for example, despite increasing R&D expenditure, animal use by pharmaceutical companies dropped by more than 25% from 2005 to 2008. In vitro studies are likewise limited: questionable cell authenticity, over-passaging, mycoplasma infections, and lack of differentiation as well as non-homeostatic and non-physiologic culture conditions endanger the relevance of these models. The standards of statistics and reporting often are poor, further impairing reliability. Alarming studies from industry show miserable reproducibility of landmark studies. This paper discusses factors contributing to the lack of reproducibility and relevance of pre-clinical research. The conclusion: Publish less but of better quality and do not rely on the face value of animal studies. PMID:23861075

  11. Cholesterol level and statin use in Alzheimer disease: I. Review of epidemiological and preclinical studies.

    PubMed

    Shepardson, Nina E; Shankar, Ganesh M; Selkoe, Dennis J

    2011-10-01

    During the last 2 decades, evidence has accumulated that a high cholesterol level may increase the risk of developing Alzheimer disease (AD). With the global use of statins to treat hypercholesterolemia, this finding has led to the anticipation that statins could prove useful in treating or preventing AD. However, the results of work on this topic are inconsistent: some studies find beneficial effects, but other studies do not. In this first segment of a 2-part review, we examine the complex preclinical and clinical literature on cholesterol level and AD. First, we review epidemiological research on cholesterol level and the risk of AD and discuss the relevance of discrepancies among studies with regard to participants' age and clinical status. Second, we assess studies correlating cholesterol level with neuropathological AD type. The potential molecular mechanisms for the apparent adverse effects of cholesterol on the development of AD are then discussed. Third, we review preclinical studies of statin use and AD. Therefore, this first part of our review provides the background and rationale for investigating statins as potential therapeutic agents in patients with AD, the subject of the second part.

  12. Evidence-based medicine in pre-clinical years: a study of early introduction and usefulness

    PubMed Central

    ACHARYA, YOGESH; RAGHAVENDRA RAO, M.V.; ARJA, SATEESH

    2017-01-01

    Introduction: Evidence Based Medicine (EBM) has established itself as a strong predictor of future medical practice by medical students. The purpose of this study was to determine the effectiveness of EBM in pre-clinical years and reflect on self-assessment skill of 4th semester medical students regarding the understanding of EBM and its various determinants. Methods: All of the 4th semester (MD4) medical students at the Avalon University of Medical School, Curacao who had completed their EBM curriculum were asked to voluntarily participate in a cross sectional student survey containing qualitative and quantitative questionnaires in a 10-point scale. The students’ responses were analyzed statistically and the results reported. Results: Twenty-three students participated in the survey. 91% of them reported that EBM had helped them to better understand research process and 95% believed that EBM was necessary to develop clinical skills in the future. 78% of the students agreed that they were provided with enough resources for effective implementation of EBM in the university. All participants (100%) self reported that they could appraise the research articles effectively (mean score 8.26, S.D-1.45). Conclusions: EBM is an integrative and comprehensive way to successfully adopt concepts of acquired medical knowledge for effective medical practice. Early introduction of EBM in preclinical years proved favorable in students and better equipped them with the ability to critically apprehend and appraise new research and innovations in medicine for optimal learning experience. There is a definitive need for scientific and systematic design of the curriculum for early introduction of EBM in pre-clinical years, best suited for the students. The principles should be directed towards further research for the effective implementation of EBM to enhance clinical skills. PMID:28761882

  13. Preclinical and clinical studies of a collagen membrane (Bio-Gide).

    PubMed

    Schlegel, A K; Möhler, H; Busch, F; Mehl, A

    1997-04-01

    Membranes are used to guide the repopulation of defects by preferred cells and to achieve a specific healing effect. The collagen membrane studied, Bio-Gide, was developed particularly for periodontal, peri-implant applications or to improve the ossification of bone defects of any origin. Bio-Gide is a bilayer membrane; one compact and smooth layer is covered by a particularly dense film, designed to prevent the invasion of soft tissue in a membrane-protected bone defect. The other, rough side of Bio-Gide must be placed towards the bone defect in order to make bone ingrowth possible. As a prerequisite for its therapeutic use in humans, the collagen matrix must be devoid of major immunogenicity. The immunological response to the membrane material was analysed in rabbits. Later, a clinical prospective study provided information about the bone regeneration effect under the Bio-Gide membrane inserted in six patients selected at random. The immune response to the collagen membrane Bio-Gide and the bone healing was tested in these patients when undergoing oral surgery.

  14. Cell-Based Meniscus Repair and Regeneration: At the Brink of Clinical Translation?: A Systematic Review of Preclinical Studies.

    PubMed

    Korpershoek, Jasmijn V; de Windt, Tommy S; Hagmeijer, Michella H; Vonk, Lucienne A; Saris, Daniel B F

    2017-02-01

    Meniscus damage can be caused by trauma or degeneration and is therefore common among patients of all ages. Repair or regeneration of the menisci could be of great importance not only for pain relief or regaining function but also to prevent degenerative disease and osteoarthritis. Current treatment does not offer consistent long-term improvement. Although preclinical research focusing on augmentation of meniscal tear repair and regeneration after meniscectomy is encouraging, clinical translation remains difficult. To systematically evaluate the literature on in vivo meniscus regeneration and explore the optimal cell sources and conditions for clinical translation. We aimed at thorough evaluation of current evidence as well as clarifying the challenges for future preclinical and clinical studies. Systematic review. A search was conducted using the electronic databases of MEDLINE, Embase, and the Cochrane Collaboration. Search terms included meniscus, regeneration, and cell-based. After screening 81 articles based on title and abstract, 51 articles on in vivo meniscus regeneration could be included; 2 additional articles were identified from the references. Repair and regeneration of the meniscus has been described by intra-articular injection of multipotent mesenchymal stromal (stem) cells from adipose tissue, bone marrow, synovium, or meniscus or the use of these cell types in combination with implantable or injectable scaffolds. The use of fibrochondrocytes, chondrocytes, and transfected myoblasts for meniscus repair and regeneration is limited to the combination with different scaffolds. The comparative in vitro and in vivo studies mentioned in this review indicate that the use of allogeneic cells is as successful as the use of autologous cells. In addition, the implantation or injection of cell-seeded scaffolds increased tissue regeneration and led to better structural organization compared with scaffold implantation or injection of a scaffold alone. None of

  15. Measuring and realizing the translational significance of preclinical in vivo studies of painful osteoarthritis.

    PubMed

    Hummel, M; Whiteside, G T

    2017-03-01

    In this communication, we discuss some key issues surrounding the translation of preclinical efficacy studies in models of painful osteoarthritis (OA) to the clinical arena. We highlight potential pitfalls which could negatively impact successful translation. These include lack of alignment between a model + endpoint and the intended clinical population, employing testing strategies in animals that are not appropriate for the targeted human population such as pre-emptive treatment and lastly, underestimating the magnitude of the efficacy signal in animals that may be needed to see an effect in the clinical population. Through careful analysis, we highlight the importance of each pitfall by providing relevant examples that will hopefully improve future chances of optimizing translation in the area of OA pain research. We advocate advancing publications directed at comparing methods, outcomes and conclusions between preclinical and clinical studies, regardless of whether the findings are positive or negative, are important for improving the potential for a desired successful translation from the bench to bedside.

  16. Alternating electric tumor treating fields for treatment of glioblastoma: rationale, preclinical, and clinical studies.

    PubMed

    Mittal, Sandeep; Klinger, Neil V; Michelhaugh, Sharon K; Barger, Geoffrey R; Pannullo, Susan C; Juhász, Csaba

    2017-02-24

    OBJECTIVE Treatment for glioblastoma (GBM) remains largely unsuccessful, even with aggressive combined treatment via surgery, radiotherapy, and chemotherapy. Tumor treating fields (TTFs) are low-intensity, intermediate-frequency, alternating electric fields that have antiproliferative properties in vitro and in vivo. The authors provide an up-to-date review of the mechanism of action as well as preclinical and clinical data on TTFs. METHODS A systematic review of the literature was performed using the terms "tumor treating fields," "alternating electric fields," "glioblastoma," "Optune," "NovoTTF-100A," and "Novocure." RESULTS Preclinical and clinical data have demonstrated the potential efficacy of TTFs for treatment of GBM, leading to several pilot studies, clinical trials, and, in 2011, FDA approval for its use as salvage therapy for recurrent GBM and, in 2015, approval for newly diagnosed GBM. CONCLUSIONS Current evidence supports the use of TTFs as an efficacious, antimitotic treatment with minimal toxicity in patients with newly diagnosed and recurrent GBM. Additional studies are needed to further optimize patient selection, determine cost-effectiveness, and assess the full impact on quality of life.

  17. Neuropharmacological Aspects of Crocus sativus L.: A Review of Preclinical Studies and Ongoing Clinical Research.

    PubMed

    Singh, Damanpreet

    2015-01-01

    Crocus sativus L. (Iridaceae) is an important member of the genus Crocus having high medicinal value. Its dried stigmas, known as "saffron" are being widely used form past many centuries as a food additive, coloring agent, flavoring agent and a potential source of traditional medicine. The stigmas along with other botanical parts of Crocus sativus are being extensively used in ethnomedical treatment of varied central nervous system diseases. In line with its ethnomedical importance, several preclinical studies have been carried out to validate its traditional uses, identify active principle(s), understand pharmacological basis of therapeutic action and explore novel medicinal uses. The bioactive components of Crocus sativus have been found to modulate several synaptic processes via direct/indirect interplay with neurotransmitter receptor functions, interaction with neuronal death/survival pathways and alteration in neuronal proteins expression. Many clinical studies proving beneficial effect of Crocus sativus in depressive disorders, Alzheimer's disease and some other neurological abnormalities have also been carried out. Based on the vast literature reports available, an attempt has been made to comprehend the fragmented information on neuropharmacological aspects, chemistry and safety of Crocus sativus. Although the plant has been well explored, but still a large scope of future preclinical and clinical research exist to explore its potential in neurological diseases, that has been discussed in depth in the present review.

  18. Molecular Pharmacology of Malignant Pleural Mesothelioma: Challenges and Perspectives From Preclinical and Clinical Studies.

    PubMed

    Thellung, Stefano; Favoni, Roberto E; Würth, Roberto; Nizzari, Mario; Pattarozzi, Alessandra; Daga, Antonio; Florio, Tullio; Barbieri, Federica

    2016-01-01

    Malignant pleural mesothelioma (MPM) is one of the deadliest and most heterogeneous tumors, highly refractory to multimodal therapeutic approach, including surgery, chemo- and radiotherapy. Preclinical and clinical studies exploring the efficacy of drugs targeting tyrosine kinases, angiogenesis and histone deacetylases, did not fulfil the expected clinical benefits. Thus, novel molecular targets should be identified from a definite knowledge of the unique biology and most relevant transduction pathways of MPM cells. Cancer stem cells (CSCs) are a subset of malignant precursors responsible for initiation, progression, resistance to cytotoxic drugs, recurrence and metastatic diffusion of tumor cells. CSCs are putative driving factors for MPM development and contribute to its clinical and biological heterogeneity; hence, targeted eradication of CSCs represents an ineludible goal to counteract MPM aggressiveness. In this context, innovative preclinical models could be exploited to identify novel intracellular pathway inhibitors able to target CSC viability. Novel drug targets have been identified among key factors responsible for the oncogenic transformation of mesothelial cells, often directly induced by asbestos. These include mitogenic and anti-apoptotic signaling that may also be activated by autocrine and paracrine cytokine pathways controlling cell plasticity. Both signaling pathways affecting proto-oncogene and transcription factor expression, or genetic and epigenetic alterations, such as mutations in cell cycle genes and silencing of tumor suppressor genes, represent promising disease-specific targets. In this review we describe current knowledge of MPM cell biology, focusing on potential targets to be tested in pharmacological studies, and highlighting results and challenges of clinical translation.

  19. Detection of Alzheimer's disease and dementia in the preclinical phase: population based cohort study.

    PubMed

    Palmer, Katie; Bäckman, Lars; Winblad, Bengt; Fratiglioni, Laura

    2003-02-01

    To evaluate a simple three step procedure to identify people in the general population who are in the preclinical phase of Alzheimer's disease and dementia. Three year population based cohort study. Kungsholmen cohort, Stockholm, Sweden. 1435 people aged 75-95 years without dementia. Single question asking about memory complaints, assessment by mini-mental state examination, and neuropsychological testing. Alzheimer's disease and dementia at three year follow up. None of the three instruments was sufficiently predictive of Alzheimer's disease and dementia when administered separately. After participants had been screened for memory complaints and global cognitive impairment, specific tests of word recall and verbal fluency had positive predictive values for dementia of 85-100% (95% confidence intervals range from 62% to 100%). However, only 18% of future dementia cases were identified in the preclinical phase by this three step procedure. Memory complaints were the most sensitive indicator of Alzheimer's disease and dementia in the whole population, but only half the future dementia cases reported memory problems three years before diagnosis. This three step procedure, which simulates what might occur in clinical practice, has a high positive predictive value for dementia, although only a small number of future cases can be identified.

  20. Pre-clinical studies with the GABAergic compounds vigabatrin and tiagabine.

    PubMed

    Sills, Graeme J

    2003-03-01

    In the last decade, nine new antiepileptic drugs have reached the global marketplace. These new agents can be categorised according to their principal mechanisms of action. Vigabatrin and tiagabine are the only new compounds with selective effects on inhibitory neurotransmission. The principal inhibitory neurotransmitter in mammalian brain is gamma-aminobutyric acid (GABA). Both vigabatrin and tiagabine exert their pharmacological effects by reducing the inactivation of GABA. Vigabatrin attenuates the metabolism of GABA by inhibiting the enzyme GABA-transaminase, whereas tiagabine blocks the uptake of GABA from the synaptic cleft by an action on the GAT-1 transporter. These mechanistic differences are borne out in a range of experimental seizure models in which vigabatrin and tiagabine have very different anticonvulsant profiles. Pre-clinical neurotoxicity and pharmacokinetic profiles also differ. Long-term vigabatrin treatment is associated with intramyelinic oedema in white matter tracts of several brain regions and further studies have revealed an accumulation of vigabatrin in the retina. In contrast, it seems that tiagabine does not precipitate any significant neurotoxicity and does not appear to accumulate in the retina. The results of these pre-clinical investigations suggest that vigabatrin and tiagabine are pharmacologically distinct compounds with different anticonvulsant, neurotoxicity and pharmacokinetic profiles. It is possible that they will ultimately prove to have different clinical efficacies and spectra of activity.

  1. Efficacy of a cathepsin K inhibitor in a preclinical model for prevention and treatment of breast cancer bone metastasis.

    PubMed

    Duong, Le T; Wesolowski, Gregg A; Leung, Patrick; Oballa, Renata; Pickarski, Maureen

    2014-12-01

    Cathepsin K (CatK) is essential for osteoclast-mediated bone resorption. CatK expression is also detected in breast cancer cells that metastasize to bone. Here, the CatK inhibitor L-235 dosed in prevention (10, 30, and 100 mg/kg, p.o., b.i.d.) or treatment regimen (30 mg/kg) was compared with the bisphosphonate zoledronic acid (ZOL, 7.5 μg/kg/wk, s.c.) in the intratibial injection model of MDA-MB-231 breast carcinoma in nude rats. Progression of osteolysis, skeletal tumor burden, and local metastasis was evaluated by radiography through 42 days and ex vivo μCT and histology. IHC and RT-PCR confirmed the increases in CatK protein and mRNA levels in human breast cancer primary and metastatic tumors. In the experimental model of breast cancer bone metastasis, L-235 dosed in preventive mode resulted in a dose-related reduction of osteolysis of 72%, 75%, and 87% respectively, compared with ZOL by 86% versus intact. Similarly, L-235 significantly reduced intratibial tumor volume by 29%, 40%, and 63%, respectively, compared with 56% by ZOL versus vehicle. Efficacy of L-235 and ZOL on reduction of osteolytic lesions and tumor burden was comparable in treatment versus preventive regimens. All L-235 doses inhibited cortical disruption and extraskeletal tumor growth to a level comparable with ZOL. Assessment of local metastasis demonstrated that treatment with the CatK inhibitor was more effective than ZOL in reducing breast cancer invasion. These data support the role of CatK in breast cancer skeletal growth and metastasis and CatK inhibitors may represent a novel oral therapy for treatment of metastatic breast cancer.

  2. Mice anesthesia, analgesia, and care, Part II: anesthetic considerations in preclinical imaging studies.

    PubMed

    Gargiulo, Sara; Greco, Adelaide; Gramanzini, Matteo; Esposito, Silvia; Affuso, Andrea; Brunetti, Arturo; Vesce, Giancarlo

    2012-01-01

    Animal experiments are necessary for a better understanding of diseases and for developing new therapeutic strategies. The mouse (Mus musculus) is currently the most popular laboratory animal in biomedical research. Mice imaging procedures are increasingly used in preclinical research because they allow in vivo monitoring and they are readily available for longitudinal and noninvasive studies as well as investigations into the evolution of diseases and the effects of new therapies. New imaging techniques and sophisticated laboratory animal imaging tools are currently producing a large body of evidence about the possible interference of anesthesia with different imaging methods that have the potential to compromise the results of in vivo studies. The purpose of this article is to review the existing literature on molecular imaging studies in mice, to describe the effects of different anesthetic protocols on their outcome, and to report our own experience with such studies.

  3. In vitro preclinical evaluation studies with the echinocandin antifungal MK-0991 (L-743,872).

    PubMed Central

    Bartizal, K; Gill, C J; Abruzzo, G K; Flattery, A M; Kong, L; Scott, P M; Smith, J G; Leighton, C E; Bouffard, A; Dropinski, J F; Balkovec, J

    1997-01-01

    The echinocandin MK-0991, formerly L-743,872, is a water-soluble lipopeptide that has been demonstrated in preclinical studies to have potent activity against Candida spp., Aspergillus fumigatus, and Pneumocystis carinii. An extensive in vitro biological evaluation of MK-0991 was performed to better define the potential activities of this novel compound. Susceptibility testing with MK-0991 against approximately 200 clinical isolates of Candida, Cryptococcus neoformans, and Aspergillus isolates was conducted to determine MICs and minimum fungicidal concentrations MF(s). The MFC at which 90% of isolates are inhibited for 40 C. albicans clinical isolates was 0.5 microg/ml. Susceptibility testing with panels of antifungal agent-resistant species of Candida and C. neoformans isolates indicated that the MK-0991 MFCs for these isolates are comparable to those obtained for susceptible isolates. Growth kinetic studies of MK-0991 against Candida albicans and Candida tropicalis isolates showed that the compound exhibited fungicidal activity (i.e., a 99% reduction in viability) within 3 to 7 h at concentrations ranging from 0.06 to 1 microg/ml (0.25 to 4 times the MIC). Drug combination studies with MK-0991 plus amphotericin B found that this combination was not antagonistic against C. albicans, C. neoformans, or A. fumigatus in vitro. Studies with 0 to 50% pooled human or mouse serum established that fungal susceptibility to MK-0991 was not significantly influenced by the presence of human or mouse serum. Results from resistance induction studies suggested that the susceptibility of C. albicans was not altered by repeated exposure (40 passages) to MK-0991. Erythrocyte hemolysis studies with MK-0991 with washed and unwashed human or mouse erythrocytes indicated minimal hemolytic potential with this compound. These favorable results of preclinical studies support further studies with MK-0991 with humans. PMID:9371328

  4. Preclinical Studies on the Pharmacokinetics, Safety and Toxicology of Oxfendazole: Toward First in Human Studies

    PubMed Central

    Codd, Ellen E.; Ng, Hanna H.; McFarlane, Claire; Riccio, Edward S.; Doppalapudi, Rupa; Mirsalis, Jon C.; Horton, R. John; Gonzalez, Armando E.; Garcia, H. Hugo; Gilman, Robert H.

    2015-01-01

    A two-week study in rats identified target organs of oxfendazole toxicity to be bone marrow, epididymis, liver, spleen, testis, and thymus. Female rats had greater oxfendazole exposure and exhibited toxicities at lower doses than did males. Decreased WBC levels, a class effect of benzimidazole anthelminthics, returned to normal during the recovery period. The NOAEL was determined to be >5 but < 25 mg/kg/d and the MTD 100 mg/kg/d. The highest dose, 200 mg/kg/d resulted in significant toxicity and mortality, leading to euthanization of the main study animals in this group after seven days. Oxfendazole did not exhibit genetic toxicology signals in standard Ames bacterial, mouse lymphoma or rat micronucleus assays, nor did it provoke safety concerns when evaluated for behavioral effects in rats or cardiovascular safety effects in dogs. These results support the transition of oxfendazole to First in Human safety studies preliminary to its evaluation in human helminth diseases. PMID:25701764

  5. Heparin in malignant glioma: review of preclinical studies and clinical results.

    PubMed

    Schnoor, Rosalie; Maas, Sybren L N; Broekman, Marike L D

    2015-09-01

    Glioblastoma multiforme (GBM) is the most common primary brain tumor that is invariably lethal. Novel treatments are desperately needed. In various cancers, heparin and its low molecular weight derivatives (LMWHs), commonly used for the prevention and treatment of thrombosis, have shown therapeutic potential. Here we systematically review preclinical and clinical studies of heparin and LMWHs as anti-tumor agents in GBM. Even though the number of studies is limited, there is suggestive evidence that heparin may have various effects on GBM. These effects include the inhibition of tumor growth and angiogenesis in vitro and in vivo, and the blocking of uptake of extracellular vesicles. However, heparin can also block the uptake of (potential) anti-tumor agents. Clinical studies suggest a non-significant trend of prolonged survival of LMWH treated GBM patients, with some evidence of increased major bleedings. Heparin mimetics lacking anticoagulant effect are therefore a potential alternative to heparin/LMWH and are discussed as well.

  6. A Longitudinal Low Dose μCT Analysis of Bone Healing in Mice: A Pilot Study

    PubMed Central

    Di, Lu-Zhao; Leblanc, Élisabeth; Alinejad, Yasaman; Beaudoin, Jean-François; Lecomte, Roger; Berthod, François; Faucheux, Nathalie; Balg, Frédéric

    2014-01-01

    Low dose microcomputed tomography (μCT) is a recently matured technique that enables the study of longitudinal bone healing and the testing of experimental treatments for bone repair. This imaging technique has been used for studying craniofacial repair in mice but not in an orthopedic context. This is mainly due to the size of the defects (approximately 1.0 mm) in long bone, which heal rapidly and may thus negatively impact the assessment of the effectiveness of experimental treatments. We developed a longitudinal low dose μCT scan analysis method combined with a new image segmentation and extraction software using Hounsfield unit (HU) scores to quantitatively monitor bone healing in small femoral cortical defects in live mice. We were able to reproducibly quantify bone healing longitudinally over time with three observers. We used high speed intramedullary reaming to prolong healing in order to circumvent the rapid healing typical of small defects. Bone healing prolongation combined with μCT imaging to study small bone defects in live mice thus shows potential as a promising tool for future preclinical research on bone healing. PMID:25431676

  7. Preclinical examination of clofarabine in pediatric ependymoma: intratumoral concentrations insufficient to warrant further study.

    PubMed

    Patel, Yogesh T; Jacus, Megan O; Boulos, Nidal; Dapper, Jason D; Davis, Abigail D; Vuppala, Pradeep K; Freeman, Burgess B; Mohankumar, Kumarasamypet M; Throm, Stacy L; Gilbertson, Richard J; Stewart, Clinton F

    2015-05-01

    Clofarabine, a deoxyadenosine analog, was an active anticancer drug in our in vitro high-throughput screening against mouse ependymoma neurospheres. To characterize the clofarabine disposition in mice for further preclinical efficacy studies, we evaluated the plasma and central nervous system disposition in a mouse model of ependymoma. A plasma pharmacokinetic study of clofarabine (45 mg/kg, IP) was performed in CD1 nude mice bearing ependymoma to obtain initial plasma pharmacokinetic parameters. These estimates were used to derive D-optimal plasma sampling time points for cerebral microdialysis studies. A simulation of clofarabine pharmacokinetics in mice and pediatric patients suggested that a dosage of 30 mg/kg IP in mice would give exposures comparable to that in children at a dosage of 148 mg/m(2). Cerebral microdialysis was performed to study the tumor extracellular fluid (ECF) disposition of clofarabine (30 mg/kg, IP) in the ependymoma cortical allografts. Plasma and tumor ECF concentration-time data were analyzed using a nonlinear mixed effects modeling approach. The median unbound fraction of clofarabine in mouse plasma was 0.79. The unbound tumor to plasma partition coefficient (K pt,uu: ratio of tumor to plasma AUCu,0-inf) of clofarabine was 0.12 ± 0.05. The model-predicted mean tumor ECF clofarabine concentrations were below the in vitro 1-h IC50 (407 ng/mL) for ependymoma neurospheres. Thus, our results show the clofarabine exposure reached in the tumor ECF was below that associated with an antitumor effect in our in vitro washout study. Therefore, clofarabine was de-prioritized as an agent to treat ependymoma, and further preclinical studies were not pursued.

  8. Preclinical examination of clofarabine in pediatric ependymoma: Intratumoral concentrations insufficient to warrant further study

    PubMed Central

    Patel, Yogesh T.; Jacus, Megan O.; Boulos, Nidal; Dapper, Jason D.; Davis, Abigail D.; Vuppala, Pradeep K.; Freeman, Burgess B.; Mohankumar, Kumarasamypet M.; Throm, Stacy L.; Gilbertson, Richard J.; Stewart, Clinton F.

    2015-01-01

    Clofarabine, a deoxyadenosine analog, was an active anticancer drug in our in vitro high-throughput screening against mouse ependymoma neurospheres. To characterize the clofarabine disposition in mice for further preclinical efficacy studies, we evaluated the plasma and central nervous system (CNS) disposition in a mouse model of ependymoma. A plasma pharmacokinetic study of clofarabine (45 mg/kg, IP) was performed in CD1 nude mice bearing ependymoma to obtain initial plasma pharmacokinetic parameters. These estimates were used to derive D-optimal plasma sampling time-points for cerebral microdialysis studies. A simulation of clofarabine pharmacokinetics in mice and pediatric patients suggested that a dosage of 30 mg/kg, IP in mice would give exposures comparable to that in children at a dosage of 148 mg/m2. Cerebral microdialysis was performed to study the tumor extracellular fluid (ECF) disposition of clofarabine (30 mg/kg, IP) in the ependymoma cortical allografts. Plasma and tumor ECF concentration-time data were analyzed using a nonlinear mixed effects modeling approach. The median unbound fraction of clofarabine in mouse plasma was 0.79. The unbound tumor to plasma partition coefficient (Kpt,uu: ratio of tumor to plasma AUCu,0-inf) of clofarabine was 0.12±0.05. The model predicted mean tumor ECF clofarabine concentrations were below the in vitro 1-hr IC50 (407 ng/mL) for ependymoma neurospheres. Thus, our results show the clofarabine exposure reached in the tumor ECF was below that associated with an antitumor effect in our in vitro washout study. Therefore, clofarabine was de-prioritized as an agent to treat ependymoma, and further preclinical studies were not pursued. PMID:25724157

  9. Pig models of neurodegenerative disorders: Utilization in cell replacement-based preclinical safety and efficacy studies.

    PubMed

    Dolezalova, Dasa; Hruska-Plochan, Marian; Bjarkam, Carsten R; Sørensen, Jens Christian H; Cunningham, Miles; Weingarten, David; Ciacci, Joseph D; Juhas, Stefan; Juhasova, Jana; Motlik, Jan; Hefferan, Michael P; Hazel, Tom; Johe, Karl; Carromeu, Cassiano; Muotri, Alysson; Bui, Jack; Strnadel, Jan; Marsala, Martin

    2014-08-15

    An important component for successful translation of cell replacement-based therapies into clinical practice is the utilization of large animal models to conduct efficacy and/or safety cell dosing studies. Over the past few decades, several large animal models (dog, cat, nonhuman primate) were developed and employed in cell replacement studies; however, none of these models appears to provide a readily available platform to conduct effective and large-scale preclinical studies. In recent years, numerous pig models of neurodegenerative disorders were developed using both a transgenic approach as well as invasive surgical techniques. The pig model (naïve noninjured animals) was recently used successfully to define the safety and optimal dosing of human spinal stem cells after grafting into the central nervous system (CNS) in immunosuppressed animals. The data from these studies were used in the design of a human clinical protocol used in amyotrophic lateral sclerosis (ALS) patients in a Phase I clinical trial. In addition, a highly inbred (complete major histocompatibility complex [MHC] match) strain of miniature pigs is available which permits the design of comparable MHC combinations between the donor cells and the graft recipient as used in human patients. Jointly, these studies show that the pig model can represent an effective large animal model to be used in preclinical cell replacement modeling. This review summarizes the available pig models of neurodegenerative disorders and the use of some of these models in cell replacement studies. The challenges and potential future directions in more effective use of the pig neurodegenerative models are also discussed.

  10. Bone marrow-derived cell therapy in chagasic cardiac disease: a review of pre-clinical and clinical results

    PubMed Central

    Carvalho, Adriana Bastos; Mello, Debora Bastos; Goldenberg, Regina Coeli dos Santos

    2012-01-01

    Chagas disease is caused by a protozoan parasite Trypanosoma cruzi, which infects people through blood sucking insects. It is endemic in Latin America and the disease is being spread to developed countries as a result of the migration of infected individuals. In its chronic stage, Chagas disease can lead to a severe cardiomyopathy for which there is currently no cure. End-stage patients require heart transplantation, thus demanding new therapeutic modalities. Cell-based therapy has been proposed as an alternative for various forms of heart disease. Here we review the experimental evidence that led to the use of bone marrow-derived cells in putative therapy for chronic chagasic cardiomyopathy in animal models and in clinical trials, discussing the reasons for failure of the translation of results from mice to men. PMID:24282718

  11. Combination of chemotherapy and cancer stem cell targeting agents: Preclinical and clinical studies.

    PubMed

    Li, Yanyan; Atkinson, Katharine; Zhang, Tao

    2017-03-12

    The cancer stem cell model claims that the initiation, maintenance, and growth of a tumor are driven by a small population of cancer cells termed cancer stem cells. Cancer stem cells possess a variety of phenotypes associated with therapeutic resistance and often cause recurrence of the diseases. Several strategies have been investigated to target cancer stem cells in a variety of cancers, such as blocking one or more self-renewal signaling pathways, reducing the expression of drug efflux and ATP-binding cassette efflux transporters, modulating epigenetic aberrations, and promoting cancer stem cell differentiation. A number of cell and animal studies strongly support the potential benefits of combining chemotherapeutic drugs with cancer stem cell targeting agents. Clinical trials are still underway to address the pharmacokinetics, safety, and efficacy of combination treatment. This mini-review provides an updated discussion of these preclinical and clinical studies.

  12. Anti-Hsp90 therapy in autoimmune and inflammatory diseases: a review of preclinical studies.

    PubMed

    Tukaj, Stefan; Węgrzyn, Grzegorz

    2016-03-01

    Heat shock protein 90 (Hsp90), a 90-kDa molecular chaperone, is responsible for biological activities of key signaling molecules (clients) such as protein kinases, ubiquitin ligases, steroid receptors, cell cycle regulators, and transcription factors regulating various cellular processes, including growth, survival, differentiation, and apoptosis. Because Hsp90 is also involved in stabilization of oncogenic 'client' proteins, its specific chaperone activity blockers are currently being tested as anticancer agents in advanced clinical trials. Recent in vitro and in vivo studies have shown that Hsp90 is also involved in activation of innate and adaptive cells of the immune system. For these reasons, pharmacological inhibition of Hsp90 has been evaluated in murine models of autoimmune and inflammatory diseases. This mini-review summarizes current knowledge of the effects of Hsp90 inhibitors on autoimmune and inflammatory diseases' features and is based solely on preclinical studies.

  13. Ethical challenges in preclinical Alzheimer’s disease observational studies and trials: results of the Barcelona summit

    PubMed Central

    Molinuevo, José L.; Cami, Jordi; Carné, Xavier; Carrillo, Maria C.; Georges, Jean; Isaac, Maria B.; Khachaturian, Zaven; Kim, Scott Y. H.; Morris, John C.; Pasquier, Florence; Ritchie, Craig; Sperling, Reisa; Karlawish, Jason

    2016-01-01

    Alzheimer’s disease (AD) is among the most significant healthcare burdens. Disappointing results from clinical trials in late-stage AD persons combined with hopeful results from trials in persons with early-stage suggest that research in the preclinical stage of AD is necessary to define an optimal therapeutic success window. We review the justification for conducting trials in the preclinical stage and highlight novel ethical challenges that arise and are related to determining appropriate risk-benefit ratios and disclosing individuals’ biomarker status. We propose that to conduct clinical trials with these participants, we need to improve public understanding of AD using unified vocabulary, resolve the acceptable risk-benefit ratio in asymptomatic participants and disclose or not biomarker status with attention to study type (observational studies versus clinical trials). Overcoming these challenges will justify clinical trials in preclinical AD at the societal level and aid to the development of societal and legal support for trial participants. PMID:26988427

  14. Systematic reviews and meta-analysis of preclinical studies: why perform them and how to appraise them critically.

    PubMed

    Sena, Emily S; Currie, Gillian L; McCann, Sarah K; Macleod, Malcolm R; Howells, David W

    2014-05-01

    The use of systematic review and meta-analysis of preclinical studies has become more common, including those of studies describing the modeling of cerebrovascular diseases. Empirical evidence suggests that too many preclinical experiments lack methodological rigor, and this leads to inflated treatment effects. The aim of this review is to describe the concepts of systematic review and meta-analysis and consider how these tools may be used to provide empirical evidence to spur the field to improve the rigor of the conduct and reporting of preclinical research akin to their use in improving the conduct and reporting of randomized controlled trials in clinical research. As with other research domains, systematic reviews are subject to bias. Therefore, we have also suggested guidance for their conduct, reporting, and critical appraisal.

  15. A preclinical and clinical study of mycophenolate mofetil in pancreatic cancer.

    PubMed

    Rodríguez-Pascual, J; Sha, P; García-García, E; Rajeshkumar, N V; De Vicente, E; Quijano, Y; Cubillo, A; Angulo, B; Hernando, O; Hidalgo, M

    2013-02-01

    A high throughput screening for anticancer activity of FDA approved drugs identified mycophenolic acid (MPA), an inhibitor of inositol monophosphate dehydrogenase (IMPDH) as an active agent with an antiangiogenesis mode of action. Exposure of pancreatic cancer cell lines to MPA resulted in growth inhibition and reduced the expression of VEGF that was reversed by supplementing the media with guanosine supporting and IMPDH-dependant mechanism. In preclinical in vivo study, MPA showed a moderate inhibition of tumor growth in a panel of 6 human derived pancreatic cancer xenografts but reduced the expression of VEGF. To investigate the effects of MPA in human pancreatic cancer, a total of 12 patients with resectable pancreatic cancer (PDA) received increasing doses of mycophenolate mofetil (MMF) in cohorts of 6 patients each from 5-15 days prior to surgical resection. Treatment was well tolerated with one episode of grade 1 muscle pain, one episode of grade 2 lymphopenia (2 gr/day dose) and one episode of grade 2 elevantion in LFT (all in the 2 gr./day dose). Patients recovered from surgery uneventfully with no increased post-operative complications. Assessment of CD31, VEGF, and TUNEL in resected specimens compared to a non treated control of 6 patients showed no significant variations in any of the study endpoints. In conclusion, this study shows the feasibility of translating a preclinical observation to the clinical setting and to explore a drug mechanism of action in patients. MPA, however, did not show any hints of antiangiogenesis of anticancer clinical activity questioning if this agent should be further developed in PDA.

  16. Improving the Predictive Value of Preclinical Studies in Support of Radiotherapy Clinical Trials

    PubMed Central

    Coleman, C. Norman; Higgins, Geoff S.; Brown, J. Martin; Baumann, Michael; Kirsch, David G.; Willers, Henning; Prasanna, Pataje G.S.; Dewhirst, Mark W.; Bernhard, Eric J.; Ahmed, Mansoor M.

    2016-01-01

    There is an urgent need to improve reproducibility and translatability of preclinical data in order to fully exploit opportunities for molecular therapeutics involving radiation and radio-chemotherapy. For in vitro the clonogenic assay remains the current state-of-the-art of preclinical assays, while newer moderate- and high-throughput assays offer the potential for rapid initial screening. Studies of radiation response modification by molecularly targeted agents can be improved using more physiologic 3D culture models. Elucidating effects on the cancer stem cells (CSC, and CSC-like) and developing biomarkers for defining targets and measuring responses are also important. In vivo studies are necessary to confirm in vitro findings, further define mechanism of action and address immune modulation and treatment-induced modification of the microenvironment. Newer in vivo models include genetically engineered and patient derived xenograft mouse models and spontaneously occurring cancers in domesticated animals. Selection of appropriate endpoints is important for in vivo studies, for example, regrowth delay measures bulk tumor killing while local tumor control assesses effects on CSC. The reliability of individual assays requires standardization of procedures and cross-laboratory validation. Radiation modifiers must be tested as part of clinical standard of care, which includes radio-chemotherapy for most tumors. Radiation models are compatible with, but also differ from those used for drug screening. Furthermore, the mechanism of a drug as a chemotherapy enhancer may be different than its interaction with radiation and/or radio-chemotherapy. This provides an opportunity to expand the use of molecular-targeted agents. PMID:27154913

  17. Contribution of Large Pig for Renal Ischemia-Reperfusion and Transplantation Studies: The Preclinical Model

    PubMed Central

    Giraud, S.; Favreau, F.; Chatauret, N.; Thuillier, R.; Maiga, S.; Hauet, T.

    2011-01-01

    Animal experimentation is necessary to characterize human diseases and design adequate therapeutic interventions. In renal transplantation research, the limited number of in vitro models involves a crucial role for in vivo models and particularly for the porcine model. Pig and human kidneys are anatomically similar (characterized by multilobular structure in contrast to rodent and dog kidneys unilobular). The human proximity of porcine physiology and immune systems provides a basic knowledge of graft recovery and inflammatory physiopathology through in vivo studies. In addition, pig large body size allows surgical procedures similar to humans, repeated collections of peripheral blood or renal biopsies making pigs ideal for medical training and for the assessment of preclinical technologies. However, its size is also its main drawback implying expensive housing. Nevertheless, pig models are relevant alternatives to primate models, offering promising perspectives with developments of transgenic modulation and marginal donor models facilitating data extrapolation to human conditions. PMID:21403881

  18. Animal extrapolation in preclinical studies: An analysis of the tragic case of TGN1412.

    PubMed

    Lemoine, Maël

    2017-02-01

    According to the received view, the transportation view, animal extrapolation consists in inductive prediction of the outcome of a mechanism in a target, based on an analogical mechanism in a model. Through an analysis of the failure of preclinical studies of TGN1412, an innovative drug, to predict the tragic consequences of its first-in-man trial in 2006, the received view is challenged by a proposed view of animal extrapolation, the chimera view. According to this view, animal extrapolation is based on a hypothesis about how human organisms work, supported by the amalgamation of results drawn from various experimental organisms, and only predicting the 'predictive grid', that is, a global framework of the effects to be expected.

  19. The interactions of anticancer agents with tea catechins: current evidence from preclinical studies.

    PubMed

    Shang, Weihu; Lu, Weidong; Han, Mei; Qiao, Jinping

    2014-01-01

    Tea catechins exhibit a broad range of pharmacological activities that impart beneficial effects on human health. Epigallocatechin-3-gallate (EGCG), one of the major tea catechins, has been widely associated with cancer prevention and treatment. In addition, tea catechins in combination with anticancer drugs are being evaluated as a new cancer treatment strategy. However, the interactions of anticancer drugs with tea catechins are largely unknown. Accumulated data indicate significant interactions between anticancer drugs and tea catechins, such as synergistic tumor inhibition or antagonist activity. Therefore, it is critical to understand comprehensively the effects of tea catechins on anticancer drugs. Focusing on evidence from preclinical studies, this paper will review the interactions between anticancer drugs and tea catechins, including pharmacodynamics and pharmacokinetics effects. We hope that by detailing the interactions between anticancer drugs and tea catechins, more attention will be directed to this important therapeutic combination in the future.

  20. Preclinical animal acute toxicity studies of new developed MRI contrast agent based on gadolinium

    NASA Astrophysics Data System (ADS)

    Nam, I. F.; Zhuk, V. V.

    2015-04-01

    Acute toxicity test of new developed MRI contrast agent based on disodium salt of gadopentetic acid complex were carried out on Mus musculus and Sprague Dawley rats according to guidelines of preclinical studies [1]. Groups of six animals each were selected for experiment. Death and clinical symptoms of animals were recorded during 14 days. As a result the maximum tolerated dose (MTD) for female mice is 2.8 mM/kg of body weight, male mice - 1.4 mM/kg, female rats - 2.8 mM/kg, male rats - 5.6 mM/kg of body weight. No Observed Adverse Effect Dose (NOAEL) for female mice is 1.4 mM/kg, male mice - 0.7 mM/kg, male and female rats - 0.7 mM/kg. According to experimental data new developed MRI contrast agent based on Gd-DTPA complex is low-toxic.

  1. Radionuclide studies of bone metabolism: do bone uptake and bone plasma clearance provide equivalent measurements of bone turnover?

    PubMed

    Blake, Glen M; Siddique, Musib; Frost, Michelle L; Moore, Amelia E B; Fogelman, Ignac

    2011-09-01

    Quantitative radionuclide imaging using (18)F-fluoride positron emission tomography (18F-PET) or (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) bone scans provides a novel tool for studying regional and whole skeleton bone turnover that complements the information provided by biochemical markers. Radionuclide bone scans can be quantified by measuring either tracer uptake or, if blood sampling is performed, bone plasma clearance. This study examines whether these two methods provide equivalent information about bone turnover. We examined data from two clinical trials of the bone anabolic agent teriparatide. In Study 1 twenty osteoporotic women had 18F-PET scans of the lumbar spine at baseline and after 6 months treatment with teriparatide. Bone uptake in the lumbar spine was expressed as standardised uptake values (SUV) and blood samples taken to evaluate plasma clearance. In Study 2 ten women had (99m)Tc-MDP scans at baseline, 3 and 18 months after starting teriparatide. Blood samples were taken and whole skeleton plasma clearance and bone uptake calculated. In Study 1 spine plasma clearance increased by 23.8% after 6-months treatment (P=0.0003), whilst SUV increased by only 3.0% (P=0.84). In Study 2 whole skeleton plasma clearance increased by 37.1% after 18-months treatment (P=0.0002), whilst the 4-hour whole skeleton uptake increased by only 25.5% (P=0.0001). During treatment the 18F- plasma concentration decrease by 20% and (99m)Tc-MDP concentration by 13%, and these latter changes were sufficient to explain the differences between the uptake and plasma clearance results. Measurements of response to treatment using bone uptake and plasma clearance gave different results because the effects of teriparatide on bone resulted in a sufficiently increased demand for radionuclide tracer from the skeleton that the concentration in the circulation decreased. Similar effects may occur with other therapies that have a large enough effect on bone metabolism. In these

  2. Impregnation of bone chips with alendronate and cefazolin, combined with demineralized bone matrix: a bone chamber study in goats

    PubMed Central

    2012-01-01

    Background Bone grafts from bone banks might be mixed with bisphosphonates to inhibit the osteoclastic response. This inhibition prevents the osteoclasts to resorb the allograft bone before new bone has been formed by the osteoblasts, which might prevent instability. Since bisphosphonates may not only inhibit osteoclasts, but also osteoblasts and thus bone formation, we studied different bisphosphonate concentrations combined with allograft bone. We investigated whether locally applied alendronate has an optimum dose with respect to bone resorption and formation. Further, we questioned whether the addition of demineralized bone matrix (DBM), would stimulate bone formation. Finally, we studied the effect of high levels of antibiotics on bone allograft healing, since mixing allograft bone with antibiotics might reduce the infection risk. Methods 25 goats received eight bone conduction chambers in the cortical bone of the proximal medial tibia. Five concentrations of alendronate (0, 0.5 mg/mL, 1 mg/mL, 2 mg/mL, and 10 mg/mL) were tested in combination with allograft bone and supplemented with cefazolin (200 μg/mL). Allograft not supplemented with alendronate and cefazolin served as control. In addition, allograft mixed with demineralized bone matrix, with and without alendronate, was tested. After 12 weeks, graft bone area and new bone area were determined with manual point counting. Results Graft resorption decreased significantly (p < 0.001) with increasing alendronate concentration. The area of new bone in the 1 mg/mL alendronate group was significantly (p = 0.002) higher when compared to the 10 mg/mL group. No differences could be observed between the group without alendronate, but with demineralized bone, and the control groups. Conclusions A dose-response relationship for local application of alendronate has been shown in this study. Most new bone was present at 1 mg/mL alendronate. Local application of cefazolin had no effect on bone remodelling. PMID:22443362

  3. Integration of preclinical and clinical knowledge to predict intravenous PK in human: bilastine case study.

    PubMed

    Vozmediano, Valvanera; Ortega, Ignacio; Lukas, John C; Gonzalo, Ana; Rodriguez, Monica; Lucero, Maria Luisa

    2014-03-01

    Modern pharmacometrics can integrate and leverage all prior proprietary and public knowledge. Such methods can be used to scale across species or comparators, perform clinical trial simulation across alternative designs, confirm hypothesis and potentially reduce development burden, time and costs. Crucial yet typically lacking in integration is the pre-clinical stage. Prediction of PK in man, using in vitro and in vivo studies in different animal species, is increasingly well theorized but could still find wider application in drug development. The aim of the present work was to explore methods for bridging pharmacokinetic knowledge from animal species (i.v. and p.o.) and man (p.o.) into i.v. in man using the antihistamine drug bilastine as example. A model, predictive of i.v. PK in man, was developed on data from two pre-clinical species (rat and dog) and p.o. in man bilastine trials performed earlier. In the knowledge application stage, two different approaches were used to predict human plasma concentration after i.v. of bilastine: allometry (several scaling methods) and a semi-physiological method. Both approaches led to successful predictions of key i.v. PK parameters of bilastine in man. The predictive i.v. PK model was validated using later data from a clinical study of i.v. bilastine. Introduction of such knowledge in development permits proper leveraging of all emergent knowledge as well as quantification-based exploration of PK scenario, e.g. in special populations (pediatrics, renal insufficiency, comedication). In addition, the methods permit reduction or elimination and certainly optimization of learning trials, particularly those concerning alternative off-label administration routes.

  4. Synthesis and preclinical pharmacokinetic study of DHA-10, a novel potential antifungal pogostone analogue.

    PubMed

    Liu, Ming; Zhou, Yanfen; Zhu, Jianwei; Ma, Bo; Fang, Zheng; Zhang, Qi

    2017-09-01

    The emergence of fungal disease calls for the urgency of development of novel drug. In this study, we developed a novel pogostone analogue, DHA-10 and investigated its preclinical pharmacokinetics, tissue distribution, excretion and protein binding rate in rats. DHA-10 was synthesized with dehydroacetic acid (DHA) as the starting material and the structure confirmed by NMR and HRMS. The LC-MS/MS was applied to quantitative analysis of DHA-10 concentrations in the biological samples. DHA-10 was eliminated rapidly in rat plasma with half-lives of 3.39 ± 0.5, 3.24 ± 0.32 and 3.80 ± 0.40 h after single oral doses of 70, 140 and 280 mg/kg, respectively, and showed linear pharmacokinetic within the examined dosage range. The oral bioavailability of DHA-10 was 69.09 ± 3.9%. DHA-10 distributed widely in tissues with highest tissue concentration was found in small intestine at 2.5 h postdose, followed by the stomach, liver and uterus. Approximately, 1.50 ± 0.26% and 9.12 ± 2.53% of parent drug was excreted via the urine and faeces within 48 h, respectively; 1.45 ± 0.12% was excreted into the bile up to 36 h after a single oral administration of 140 mg/kg. Binding rate of DHA-10 with plasma protein was about 78.80 ± 1.75% in a concentration-independent manner. DHA-10 was successfully synthesized and characterized. The preclinical pharmacokinetics study in rats supported the further development of this new antifungal candidate compound. © 2017 Royal Pharmaceutical Society.

  5. Optimization and Preclinical Perception of an Artificial Simulator for Endodontic Training: A Preliminary Study.

    PubMed

    Robberecht, Lieven; Hornez, Jean-Christophe; Dehurtevent, Marion; Dufour, Thomas; Labreuche, Julien; Deveaux, Etienne; Chai, Feng

    2017-03-01

    The aim of this study was to evaluate the performance of ceramic, hybrid ceramic, and commercial plastic bloc root canal simulator (RCS) as preclinical training aids in the learning phase of endodontic treatments. A previously developed hydroxyapatite ceramic RCS was improved by adding epoxy resin to the ceramic matrix to more closely mimic the organic phase of dentin and to simulate the clinical situation as realistically as possible. The sintered hydroxyapatite ceramic RCS was vacuum infiltrated with epoxy resin, and the degree of infiltration was evaluated by methylene blue staining. The suitability of the resin-infiltrated ceramic simulator (CR) for preclinical endodontic training was compared to that of a non-infiltrated ceramic simulator (C) and a commercial epoxy bloc (P) using a cohort of 30 dental students at one dental school in France. The study was conducted in 2016. The students' perceptions following the required exercises using the CR, C, and P were scored using a questionnaire. The learning outcomes were also assessed by examining the canal preparations that the students performed on extracted teeth using a master cone try-in test. The vacuum process resulted in a good degree of resin infiltration into the ceramic. The questionnaire showed that the C and CR groups generally reported greater satisfaction, especially for radiographic visualizations, than the P group. The CR group had a higher score than the P group for tactile sensation. There was no significant difference among the three groups with respect to the canal preparations using extracted teeth. Resin infiltration improved the performance of the ceramic RCS, especially with respect to perception during root canal instrumentation. A larger scale student training investigation and an assessment by experienced endodontists are required to validate the model.

  6. Preclinical and Clinical Evidence of Mycobacterium tuberculosis Persistence in the Hypoxic Niche of Bone Marrow Mesenchymal Stem Cells after Therapy.

    PubMed

    Garhyan, Jaishree; Bhuyan, Seema; Pulu, Ista; Kalita, Deepjyoti; Das, Bikul; Bhatnagar, Rakesh

    2015-07-01

    Mycobacterium tuberculosis (MTB), the causative agent of pulmonary tuberculosis, is difficult to eliminate by antibiotic therapy. We recently identified CD271(+) bone marrow-mesenchymal stem cells (BM-MSCs) as a potential site of MTB persistence after therapy. Herein, we have characterized the potential hypoxic localization of the post-therapy MTB-infected CD271(+) BM-MSCs in both mice and human subjects. We first demonstrate that in a Cornell model of MTB persistence in mice, green fluorescent protein-labeled virulent MTB-strain H37Rv was localized to pimonidazole (an in vivo hypoxia marker) positive CD271(+) BM-MSCs after 90 days of isoniazid and pyrazinamide therapy that rendered animal's lung noninfectious. The recovered CD271(+) BM-MSCs from post-therapy mice, when injected into healthy mice, caused active tuberculosis infection in the animal's lung. Moreover, MTB infection significantly increased the hypoxic phenotype of CD271(+) BM-MSCs. Next, in human subjects, previously treated for pulmonary tuberculosis, the MTB-containing CD271(+) BM-MSCs exhibited high expression of hypoxia-inducible factor 1α and low expression of CD146, a hypoxia down-regulated cell surface marker of human BM-MSCs. These data collectively demonstrate the potential localization of MTB harboring CD271(+) BM-MSCs in the hypoxic niche, a critical microenvironmental factor that is well known to induce the MTB dormancy phenotype. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  7. Potential Role of Local Estrogen in Enhancement of Fracture Healing: Preclinical Study in Rabbits

    PubMed Central

    Tahami, Mohammad; Haddad, Behrooz; Abtahian, Armin; Hashemi, Ali; Aminian, Amir; Konan, Sujith

    2016-01-01

    Background: Effects of estrogen on bone metabolism and its protective role on prevention of osteoporosis are well documented. However, the efficacy of estrogen treatment on bone healing is not well investigated. The drug can be delivered both systemically or locally to the bone with differences in concentrations and side effects. The aim of this study was to investigate the effect of local and systemic administration of estrogen on the fracture healing process. Methods: Standardized tibial fractures with 4 millimeter gaps were created in twenty four adult male Dutch rabbits. Fractures were fixed using intramedullary wires and long leg casts. Rabbits were randomly divided into three groups. Group A was treated with twice a week administration of long acting systemic estrogen; group B was treated with a similar regimen given locally at the fracture gap; and group C received sham normal saline injections (control). Fracture healing was assessed at six weeks post fracture by gross examination, radiographic and histomorphometric analysis. Results: Group B had significantly higher gross stability, radiographic union and gap reduction than the two other groups. Histomorphometric analysis showed higher cartilaginous proportion of periosteal callus area in the control group. Conclusions: Our results showed that estrogen may enhance fracture healing of long bone in rabbits. Furthermore, local estrogen treatment might have better effect than systemic treatment. PMID:27847844

  8. Nonindustry-sponsored preclinical studies on statins yield greater efficacy estimates than industry-sponsored studies: a meta-analysis.

    PubMed

    Krauth, David; Anglemyer, Andrew; Philipps, Rose; Bero, Lisa

    2014-01-01

    Industry-sponsored clinical drug studies are associated with publication of outcomes that favor the sponsor, even when controlling for potential bias in the methods used. However, the influence of sponsorship bias has not been examined in preclinical animal studies. We performed a meta-analysis of preclinical statin studies to determine whether industry sponsorship is associated with either increased effect sizes of efficacy outcomes and/or risks of bias in a cohort of published preclinical statin studies. We searched Medline (January 1966-April 2012) and identified 63 studies evaluating the effects of statins on atherosclerosis outcomes in animals. Two coders independently extracted study design criteria aimed at reducing bias, results for all relevant outcomes, sponsorship source, and investigator financial ties. The I(2) statistic was used to examine heterogeneity. We calculated the standardized mean difference (SMD) for each outcome and pooled data across studies to estimate the pooled average SMD using random effects models. In a priori subgroup analyses, we assessed statin efficacy by outcome measured, sponsorship source, presence or absence of financial conflict information, use of an optimal time window for outcome assessment, accounting for all animals, inclusion criteria, blinding, and randomization. The effect of statins was significantly larger for studies sponsored by nonindustry sources (-1.99; 95% CI -2.68, -1.31) versus studies sponsored by industry (-0.73; 95% CI -1.00, -0.47) (p value<0.001). Statin efficacy did not differ by disclosure of financial conflict information, use of an optimal time window for outcome assessment, accounting for all animals, inclusion criteria, blinding, and randomization. Possible reasons for the differences between nonindustry- and industry-sponsored studies, such as selective reporting of outcomes, require further study.

  9. Nonindustry-Sponsored Preclinical Studies on Statins Yield Greater Efficacy Estimates Than Industry-Sponsored Studies: A Meta-Analysis

    PubMed Central

    Krauth, David; Anglemyer, Andrew; Philipps, Rose; Bero, Lisa

    2014-01-01

    Industry-sponsored clinical drug studies are associated with publication of outcomes that favor the sponsor, even when controlling for potential bias in the methods used. However, the influence of sponsorship bias has not been examined in preclinical animal studies. We performed a meta-analysis of preclinical statin studies to determine whether industry sponsorship is associated with either increased effect sizes of efficacy outcomes and/or risks of bias in a cohort of published preclinical statin studies. We searched Medline (January 1966–April 2012) and identified 63 studies evaluating the effects of statins on atherosclerosis outcomes in animals. Two coders independently extracted study design criteria aimed at reducing bias, results for all relevant outcomes, sponsorship source, and investigator financial ties. The I2 statistic was used to examine heterogeneity. We calculated the standardized mean difference (SMD) for each outcome and pooled data across studies to estimate the pooled average SMD using random effects models. In a priori subgroup analyses, we assessed statin efficacy by outcome measured, sponsorship source, presence or absence of financial conflict information, use of an optimal time window for outcome assessment, accounting for all animals, inclusion criteria, blinding, and randomization. The effect of statins was significantly larger for studies sponsored by nonindustry sources (−1.99; 95% CI −2.68, −1.31) versus studies sponsored by industry (−0.73; 95% CI −1.00, −0.47) (p value<0.001). Statin efficacy did not differ by disclosure of financial conflict information, use of an optimal time window for outcome assessment, accounting for all animals, inclusion criteria, blinding, and randomization. Possible reasons for the differences between nonindustry- and industry-sponsored studies, such as selective reporting of outcomes, require further study. PMID:24465178

  10. Observations of veterinary medicine students' approaches to study in pre-clinical years.

    PubMed

    Ryan, Marion T; Irwin, Jane A; Bannon, Finian J; Mulholland, Clive W; Baird, Alan W

    2004-01-01

    This study has two purposes. The first is to explore an instrument of evaluation of the approaches to study (deep, strategic, and surface) adopted by students in the pre-clinical years of their veterinary degree program. The second is to examine relationships between these approaches and a broad range of further factors deemed relevant to the veterinary medicine context. We envisage that a greater knowledge of how these students learn will aid curriculum reform in a way that will enrich the learning experience of veterinary students. A questionnaire consisting of the 52-question Approaches to Study Inventory (ASI) and an additional 49 questions relating mainly to teaching, assessment, and study skills was distributed to 215 veterinary medicine (MVB) students in their pre-clinical years of study. Factor analysis was used to ensure that the ASI section of the questionnaire maintained previously reported structure. The internal reliability of the approaches measured was tested using Cronbach alpha analysis. The approaches were described as frequency distributions. Associations between the parameters (deep, strategic, and surface) and 49 additional context-specific factors were investigated using loglinear analysis. (1) Factor analysis revealed that the integrity and structure of the instrument in this context was generally comparable to previous studies. (2) The impact of a high workload was evident in the surface approach, with fear of failure becoming a strong motivating factor and syllabus boundness a widely used strategy. (3) Associations made between the approaches and 49 context-specific factors showed strong associations between both workload and lack of prior knowledge with the surface approach. (4) Grades were associated positively with both the deep and strategic approaches but negatively with the surface approach. (5) A range of learning and study skills were associated positively with the deep and strategic approaches and negatively with the surface

  11. Abuse liability assessment in preclinical drug development: predictivity of a translational approach for abuse liability testing using methylphenidate in four standardized preclinical study models.

    PubMed

    Teuns, Greet B A; Geys, Helena M; Geuens, Sonja M A; Stinissen, Piet; Meert, Theo F

    2014-01-01

    Preclinical abuse liability assessment of novel clinical CNS-active candidates involves several tests, addressing different aspects characteristic for abuse potential, which are considered predictive for substance abuse of these candidates, thus ensuring an appropriate translational approach. To demonstrate how such a strategy could work, a known drug of abuse, methylphenidate was evaluated in a full rodent test battery, comprising four test models, and in accordance with the requirements of the FDA, ICH and EMA guidelines. Methylphenidate was tested orally at 2.5, 5 or 10mg/kg for its physical dependence potential in a repeated dose non-precipitated withdrawal test, for its drug profiling in a drug discrimination learning procedure (single escalating doses), and for its reinforcing properties in a conditioned place preference test (alternate dosing days) and an intravenous self-administration procedure (0.05 to 1mg/kg/IV infusion during 5 daily 1-h test sessions). The stimulant d-amphetamine served as positive control and was administered subcutaneously at 0.8mg/kg in the first three test models. In the intravenous self-administration procedure rats were habituated to intravenously self-administer d-amphetamine at 0.06mg/kg/IV infusion prior to methylphenidate substitution. Cessation of subchronic dosing up to 10mg/kg methylphenidate led to sustained or even exacerbated effects on locomotion and behavior, body temperature, body weight, food consumption, and alteration of the diurnal rhythm during withdrawal. Clear generalization to d-amphetamine was obtained in the drug discrimination test at 5 and 10mg/kg. Distinct reinforcing properties were present in the conditioned place preference test at 10mg/kg and in the intravenous self-administration study from 0.05mg/kg/IV infusion onwards. The maximum plasma exposure after oral administration of methylphenidate over the dose ranges tested in the present rat studies covered at least 1.9-fold to 18.9-fold the

  12. Study on 41Ca-AMS for diagnosis and assessment of cancer bone metastasis in rats

    NASA Astrophysics Data System (ADS)

    Shen, Hongtao; Pang, Fangfang; Jiang, Shan; He, Ming; Dong, Kejun; Dou, Liang; Pang, Yijun; Yang, Xianlin; Ruan, Xiangdong; Liu, Manjun; Xia, Chunbo

    2015-10-01

    The annual incidence of new cancer patients in China is about 2 million, 30-40% of which will end up with bone metastasis. Profound study on the preclinical model and early diagnosis of cancer bone metastasis in rats are very significant for the drug development, better understanding and treatment of bone metastases. In order to monitor the process of bone metabolism and early detection of bone metastasis of cancer cells, a technique of 41Ca isotope tracer combined with AMS has been developed and applied in the study on the bone metastasis of cancer cells by rat model. In this work, 3-month-old female Sprague-Dawley (SD) rats were randomly divided into different groups, and tumor cells injected respectively into the tail vein, femoral artery, femoral cavity and the thigh muscle to establish the rat models for bone metastases. The most appropriate model, i.e., the thigh muscle group, was finally adopted in our real metastases experiment. Each rat in this group was intramuscularly (i.m.) injected with 250 μl CaCl2 solution (containing 1.4 mg Ca and 5nCi 41Ca). About 40 days later, the rat mammary gland carcinoma cells (Walker 256) were injected into these rats following the established protocol. After bone metastasis, medicine interventions were performed. The sequential urine and blood samples were collected and analyzed for 41Ca (by AMS) and N-terminal telopeptide (Ntx), respectively. Bone Mineral Density (BMD) values in the femur and the tibia were measured by CT scan. The results of 41Ca/Ca in longitudinal urinary samples can sensitively reveal the skeletal perturbations caused by bone metastasis of rats, suggests that 41Ca might be similarly developed for human use and improve clinical management through the assessment of the curative effect and non-invasive detection of the earliest stages of cancer growth in bone.

  13. Mouse Model for the Preclinical Study of Metastatic Disease | NCI Technology Transfer Center | TTC

    Cancer.gov

    The Laboratory of Cancer Biology and Genetics, National Cancer Institute seeks partners for collaborative research to co-develop a mouse model that shows preclinical therapeutic response of residual metastatic disease.

  14. From Mice to Men and Back: An Assessment of Preclinical Model Systems for the Study of Lung Cancers.

    PubMed

    Gazdar, Adi F; Hirsch, Fred R; Minna, John D

    2016-03-01

    Studies of preclinical models are essential for determining the biology of lung cancers and testing new and novel therapeutic approaches. We review the commonly used preclinical models for lung cancers and evaluate their strengths and weaknesses. We searched the MEDLINE database via PubMed using combinations of the following medical subject headings: lung cancer; animal models, mice; cell line, tumor; cell culture, mice; transgenic, mice; SCID, transplantation; heterologous; and genetic engineering. We reviewed the relevant published articles. Multiple examples of the three major preclinical models-tumor cell lines, patient-derived xenografts, and genetically engineered mouse models-exist and have been used by investigators worldwide, with more than 15,000 relevant publications. Each model has its strengths and actual or potential weaknesses. In addition, newer forms of these models have been proposed or are in use as potential improvements over the conventional models. A large number and variety of models have been developed and extensively used for the study of all major types of lung cancer. While they remain the cornerstone of preclinical studies, each model has its individual strengths and weaknesses. These must be carefully evaluated and applied to the proposed studies to obtain the maximum usefulness from the models. Copyright © 2015 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  15. Using Bayesian analysis in repeated preclinical in vivo studies for a more effective use of animals.

    PubMed

    Walley, Rosalind; Sherington, John; Rastrick, Joe; Detrait, Eric; Hanon, Etienne; Watt, Gillian

    2016-05-01

    Whilst innovative Bayesian approaches are increasingly used in clinical studies, in the preclinical area Bayesian methods appear to be rarely used in the reporting of pharmacology data. This is particularly surprising in the context of regularly repeated in vivo studies where there is a considerable amount of data from historical control groups, which has potential value. This paper describes our experience with introducing Bayesian analysis for such studies using a Bayesian meta-analytic predictive approach. This leads naturally either to an informative prior for a control group as part of a full Bayesian analysis of the next study or using a predictive distribution to replace a control group entirely. We use quality control charts to illustrate study-to-study variation to the scientists and describe informative priors in terms of their approximate effective numbers of animals. We describe two case studies of animal models: the lipopolysaccharide-induced cytokine release model used in inflammation and the novel object recognition model used to screen cognitive enhancers, both of which show the advantage of a Bayesian approach over the standard frequentist analysis. We conclude that using Bayesian methods in stable repeated in vivo studies can result in a more effective use of animals, either by reducing the total number of animals used or by increasing the precision of key treatment differences. This will lead to clearer results and supports the "3Rs initiative" to Refine, Reduce and Replace animals in research. Copyright © 2016 John Wiley & Sons, Ltd.

  16. From bench to bedside: utility of the rabbit elastase aneurysm model in preclinical studies of intracranial aneurysm treatment.

    PubMed

    Brinjikji, Waleed; Ding, Yong H; Kallmes, David F; Kadirvel, Ramanathan

    2016-05-01

    Preclinical studies are important in helping practitioners and device developers improve techniques and tools for endovascular treatment of intracranial aneurysms. Thus an understanding of the major animal models used in such studies is important. The New Zealand rabbit elastase induced arterial aneurysm of the common carotid artery is one of the most commonly used models in testing the safety and efficacy of new endovascular devices. In this review we discuss: (1) the various techniques used to create the aneurysm, (2) complications of aneurysm creation, (3) natural history of the arterial aneurysm, (4) histopathologic and hemodynamic features of the aneurysm, (5) devices tested using this model, and (6) weaknesses of the model. We demonstrate how preclinical studies using this model are applied in the treatment of intracranial aneurysms in humans. The model has similar hemodynamic, morphological, and histologic characteristics to human aneurysms, and demonstrates similar healing responses to coiling as human aneurysms. Despite these strengths, however, the model does have many weaknesses, including the fact that the model does not emulate the complex inflammatory processes affecting growing and ruptured aneurysms. Furthermore, the extracranial location of the model affects its ability to be used in preclinical safety assessments of new devices. We conclude that the rabbit elastase model has characteristics that make it a simple and effective model for preclinical studies on the endovascular treatment of intracranial aneurysms, but further work is needed to develop aneurysm models that simulate the histopathologic and morphologic characteristics of growing and ruptured aneurysms.

  17. Exercise as a Potential Treatment for Drug Abuse: Evidence from Preclinical Studies

    PubMed Central

    Smith, Mark A.; Lynch, Wendy J.

    2012-01-01

    Epidemiological studies reveal that individuals who engage in regular aerobic exercise are less likely to use and abuse illicit drugs. Until recently, very few studies had examined the causal influences that mediate this relationship, and it was not clear whether exercise was effective at reducing substance use and abuse. In the past few years, several preclinical studies have revealed that exercise reduces drug self-administration in laboratory animals. These studies have revealed that exercise produces protective effects in procedures designed to model different transitional phases that occur during the development of, and recover from, a substance use disorder (e.g., acquisition, maintenance, escalation, and relapse/reinstatement of drug use). Moreover, recent studies have revealed several behavioral and neurobiological consequences of exercise that may be responsible for its protective effects in these assays. Collectively, these studies have provided convincing evidence to support the development of exercise-based interventions to reduce compulsive patterns of drug intake in clinical and at-risk populations. PMID:22347866

  18. Cognitive and emotional behavioural changes associated with methylphenidate treatment: a review of preclinical studies.

    PubMed

    Britton, Gabrielle B

    2012-02-01

    There is evidence from animal studies that repeated exposure to methylphenidate (MPH), a widely used psychostimulant for the treatment of attention deficit hyperactivity disorder (ADHD), produces behavioural, structural and neurochemical changes that persist long after drug administration has ended. However, the translational utility of much of this work is compromised by the use of drug doses and routes of administration that produce plasma and brain MPH levels that fall outside the clinical range, i.e. experimental parameters more relevant to drug abuse than ADHD. We used PubMed to identify pre-clinical studies that employed repeated MPH administration at low doses in young rodents and examined long-term effects on cognition, emotion, and brain structure and function. A review of this work suggests that repeated MPH treatment during early development can modify a number of cognitive, behavioural and brain processes, but these are reduced when low therapeutic doses are employed. Moreover, MPH sites of action extend beyond those implicated in ADHD. Studies that combined neurobiological and behavioural approaches provide important insights into the mechanisms underlying MPH-produced effects on cognitive and behavioural processes, which may be relevant to MPH therapeutic efficacy. There is an emerging consensus that pharmacological treatment of childhood psychiatric disorders produces persistent neuroadaptations, highlighting the need for studies that assess long-term effects of early developmental pharmacotherapy. In this regard, studies that mimic clinical therapy with rodents are useful experimental approaches for defining the behavioural and neural plasticity associated with stimulant therapy in paediatric populations.

  19. Bioplasty for vertebral fractures: preliminary results of a pre-clinical study on goats using autologous modified skin fibroblasts

    PubMed Central

    Pola, Enrico; Nasto, Luigi A.; Tampieri, Anna; Lattanzi, W.; Di Giacomo, G.; Colangelo, D.; Ciriello, V.; Pagano, E.; Spinelli, S.; Robbins, P.D.; Logroscino, G.

    2012-01-01

    Summary The debate is still ongoing about the long term effects of the mininvasive vertebral augmentation techniques and their usefulness in treating more complex cases where a bone inducing effect more than a merely bone substitution would be suitable, such as the vertebral fractures in young patients. We previously developed a clinically relevant gene therapy approach using modified dermal fibroblasts for inducing bone healing and bone formation in different animal models. The aim of this study is to show the feasibility of a minimally invasive percutaneous intrasomatic ex vivo gene therapy approach to treat thoracolumbar vertebral fractures and anterior column bone defects in a goat model. PMID:21669153

  20. Mean sojourn time of preclinical gastric cancer in Korean men: a retrospective observational study.

    PubMed

    Bae, Jong-Myon; Shin, Sang Yop; Kim, Eun Hee

    2014-07-01

    This retrospective cohort study aimed to estimate the mean sojourn time (MST) of preclinical gastric cancer in Korean men. The subjects consisted of voluntary male screenees aged 40 to 69 years who underwent subsequent screening gastroscopies after testing negative at a baseline screening performed between January 2007 and December 2011. A new case was defined if gastric cancer cells were present in the biopsy specimens obtained from gastroscopy. The follow-up period was calculated as the number of person-years between the date of baseline screening gastroscopy and positive findings at a subsequent screening. The MST was calculated using transition rates of gastric cancer to determine the best screening interval. Of the 171 979 voluntary male screenees, 61 688 (36%) underwent subsequent screening gastroscopies between January 2007 and December 2011. A total of 91 incident cases were found during 19 598 598 person-years of follow-up. The MST of gastric cancer was 2.37 years (95% confidence intervals, 1.92 to 2.96), and those aged 40 to 49 years had a shorter MST than those 50 to 69 years did. These findings support the 2-year interval of screening recommended by the nationwide gastric cancer screening program in Korea. Further studies for the age-specific MST among women are needed. This retrospective cohort study aimed to estimate the mean sojourn time (MST) of preclinical gastric cancer in Korean men. The subjects consisted of voluntary male screenees aged 40 to 69 years who underwent subsequent screening gastroscopies after testing negative at a baseline screening performed between January 2007 and December 2011. A new case was defined if gastric cancer cells were present in the biopsy specimens obtained from gastroscopy. The follow-up period was calculated as the number of person-years between the date of baseline screening gastroscopy and positive findings at a subsequent screening. The MST was calculated using transition rates of gastric cancer to determine

  1. Spectroscopic analysis of bones for forensic studies

    NASA Astrophysics Data System (ADS)

    Tofanelli, Mirko; Pardini, Lorenzo; Borrini, Matteo; Bartoli, Fulvio; Bacci, Alessandra; D'Ulivo, Alessandro; Pitzalis, Emanuela; Mascherpa, Marco Carlo; Legnaioli, Stefano; Lorenzetti, Giulia; Pagnotta, Stefano; de Holanda Cavalcanti, Gildo; Lezzerini, Marco; Palleschi, Vincenzo

    2014-09-01

    The elemental analysis of human bones can give information about the dietary habits of the deceased, especially in the last years of their lives, which can be useful for forensic studies. The most important requirement that must be satisfied for this kind of analysis is that the concentrations of analyzed elements are the same as ante mortem. In this work, a set of bones was analyzed using Laser-Induced Breakdown Spectroscopy (LIBS) and validated using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), in order to compare those two techniques and to investigate the effect of possible alterations in the elemental concentrations' proportion resulting from the treatment usually applied for preparing the bones for traditional forensic analysis. The possibility that elemental concentrations' changes would occur after accidental or intentional burning of the bones was also studied.

  2. Design and Reporting of Targeted Anticancer Preclinical Studies: A Meta-Analysis of Animal Studies Investigating Sorafenib Antitumor Efficacy.

    PubMed

    Mattina, James; MacKinnon, Nathalie; Henderson, Valerie C; Fergusson, Dean; Kimmelman, Jonathan

    2016-08-15

    The validity of preclinical studies of candidate therapeutic agents has been questioned given their limited ability to predict their fate in clinical development, including due to design flaws and reporting bias. In this study, we examined this issue in depth by conducting a meta-analysis of animal studies investigating the efficacy of the clinically approved kinase inhibitor, sorafenib. MEDLINE, Embase, and BIOSIS databases were searched for all animal experiments testing tumor volume response to sorafenib monotherapy in any cancer published until April 20, 2012. We estimated effect sizes from experiments assessing changes in tumor volume and conducted subgroup analyses based on prespecified experimental design elements associated with internal, construct, and external validity. The meta-analysis included 97 experiments involving 1,761 animals. We excluded 94 experiments due to inadequate reporting of data. Design elements aimed at reducing internal validity threats were implemented only sporadically, with 66% reporting animal attrition and none reporting blinded outcome assessment or concealed allocation. Anticancer activity against various malignancies was typically tested in only a small number of model systems. Effect sizes were significantly smaller when sorafenib was tested against either a different active agent or combination arm. Trim and fill suggested a 37% overestimation of effect sizes across all malignancies due to publication bias. We detected a moderate dose-response in one clinically approved indication, hepatocellular carcinoma, but not in another approved malignancy, renal cell carcinoma, or when data were pooled across all malignancies tested. In support of other reports, we found that few preclinical cancer studies addressed important internal, construct, and external validity threats, limiting their clinical generalizability. Our findings reinforce the need to improve guidelines for the design and reporting of preclinical cancer studies

  3. Preclinical radiotherapy at the Australian Synchrotron's Imaging and Medical Beamline: instrumentation, dosimetry and a small-animal feasibility study.

    PubMed

    Livingstone, Jayde; Adam, Jean François; Crosbie, Jeffrey C; Hall, Chris J; Lye, Jessica E; McKinlay, Jonathan; Pelliccia, Daniele; Pouzoulet, Frédéric; Prezado, Yolanda; Stevenson, Andrew W; Häusermann, Daniel

    2017-07-01

    Therapeutic applications of synchrotron X-rays such as microbeam (MRT) and minibeam (MBRT) radiation therapy promise significant advantages over conventional clinical techniques for some diseases if successfully transferred to clinical practice. Preclinical studies show clear evidence that a number of normal tissues in animal models display a tolerance to much higher doses from MRT compared with conventional radiotherapy. However, a wide spread in the parameters studied makes it difficult to make any conclusions about the associated tumour control or normal tissue complication probabilities. To facilitate more systematic and reproducible preclinical synchrotron radiotherapy studies, a dedicated preclinical station including small-animal irradiation stage was designed and installed at the Imaging and Medical Beamline (IMBL) at the Australian Synchrotron. The stage was characterized in terms of the accuracy and reliability of the vertical scanning speed, as this is the key variable in dose delivery. The measured speed was found to be within 1% of the nominal speed for the range of speeds measured by an interferometer. Furthermore, dose measurements confirm the expected relationship between speed and dose and show that the measured dose is independent of the scan direction. Important dosimetric parameters such as peak dose, valley dose, the collimator output factor and peak-to-valley dose ratio are presented for 5 mm × 5 mm, 10 mm × 10 mm and 20 mm × 20 mm field sizes. Finally, a feasibility study on three glioma-bearing rats was performed. MRT and MBRT doses were prescribed to achieve an average dose of 65 Gy in the target, and magnetic resonance imaging follow-up was performed at various time points after irradiation to follow the tumour volume. Although it is impossible to draw conclusions on the different treatments with such a small number of animals, the feasibility of end-to-end preclinical synchrotron radiotherapy studies using the IMBL

  4. Evaluation of incidence rates in pre-clinical studies using a Williams-type procedure.

    PubMed

    Hothorn, Ludwig A; Sill, Martin; Schaarschmidt, Frank

    2010-01-01

    The analysis of dose-response relationships is a common problem in pre-clinical studies. For example, proportions such as mortality rates and histopathological findings are of particular interest in repeated toxicity studies. Commonly applied designs consist of an untreated control group and several, possibly unequally spaced, dosage groups. The Williams test can be formulated as a multiple contrast test and is a powerful option to evaluate such data. In this paper, we consider simultaneous inference for Williams-type multiple contrasts when the response variable is binomial and sample sizes are only moderate. Approximate simultaneous confidence limits can be constructed using the quantiles of a multivariate normal distribution taking the correlation into account. Alternatively, multiplicity-adjusted p-values can be calculated as well. A simulation study shows that a simple correction based on adding pseudo observations leads to acceptable performance for moderate sample sizes, such as 40 per group. In addition, the calculation of adjusted p-values and approximate power is presented. Finally, the proposed methods are applied to example data from two toxicological studies; the methods are available in an R-package.

  5. CCD-camera-based diffuse optical tomography to study ischemic stroke in preclinical rat models

    NASA Astrophysics Data System (ADS)

    Lin, Zi-Jing; Niu, Haijing; Liu, Yueming; Su, Jianzhong; Liu, Hanli

    2011-02-01

    Stroke, due to ischemia or hemorrhage, is the neurological deficit of cerebrovasculature and is the third leading cause of death in the United States. More than 80 percent of stroke patients are ischemic stroke due to blockage of artery in the brain by thrombosis or arterial embolism. Hence, development of an imaging technique to image or monitor the cerebral ischemia and effect of anti-stoke therapy is more than necessary. Near infrared (NIR) optical tomographic technique has a great potential to be utilized as a non-invasive image tool (due to its low cost and portability) to image the embedded abnormal tissue, such as a dysfunctional area caused by ischemia. Moreover, NIR tomographic techniques have been successively demonstrated in the studies of cerebro-vascular hemodynamics and brain injury. As compared to a fiberbased diffuse optical tomographic system, a CCD-camera-based system is more suitable for pre-clinical animal studies due to its simpler setup and lower cost. In this study, we have utilized the CCD-camera-based technique to image the embedded inclusions based on tissue-phantom experimental data. Then, we are able to obtain good reconstructed images by two recently developed algorithms: (1) depth compensation algorithm (DCA) and (2) globally convergent method (GCM). In this study, we will demonstrate the volumetric tomographic reconstructed results taken from tissuephantom; the latter has a great potential to determine and monitor the effect of anti-stroke therapies.

  6. Learning style preferences: A study of pre-clinical medical students in Barbados

    PubMed Central

    OJEH, NKEMCHO; SOBERS-GRANNUM, NATASHA; GAUR, UMA; UDUPA, ALAYA; MAJUMDER, MD.ANWARUL AZIM

    2017-01-01

    Introduction: Educators need to be aware of different learning styles to effectively tailor instructional strategies and methods to cater to the students’ learning needs and support a conductive learning environment. The VARK [an acronym for visual (V), aural (A), read/write (R) and kinesthetic (K)] instrument is a useful model to assess learning styles. The aim of this study was to use the VARK questionnaire to determine the learning styles of pre-clinical medical students in order to compare the perceived and assessed learning style preferences, assess gender differences in learning style preferences, and determine whether any relationships exists between awareness of learning styles and academic grades, age, gender and learning modality. Methods: The VARK questionnaire was administered to pre-clinical students taking a variety of courses in the first three years of the undergraduate MB BS degree programme at the Faculty of Medical Sciences, The University of the West Indies, Cave Hill Campus, Barbados in 2014. Results: The majority of the students were multimodal learners with no differences observed between males (59.5%) and females (60.0%), with tetramodal being the most common. Read/write (33.8%) followed by kinesthetic (32.5%) were the most common learning style preferences. The sensory modality preference for females was read/write (34.2%) and for males it was kinesthetic (40.5%). Significant differences were observed between the perceived and assessed learning style preferences with a majority of visual and read/write learners correctly matching their perceived to their actual learning styles. Awareness of learning styles was associated with learning modality but not with academic performance, age or gender. Overall, 60.7% of high achievers used multimodal learning compared to 56.9% low achievers. Conclusion: The findings from this study indicated that the VARK tool was useful in gathering information about different learning styles, and might assist

  7. Learning style preferences: A study of pre-clinical medical students in Barbados.

    PubMed

    Ojeh, Nkemcho; Sobers-Grannum, Natasha; Gaur, Uma; Udupa, Alaya; Majumder, Md Anwarul Azim

    2017-10-01

    Educators need to be aware of different learning styles to effectively tailor instructional strategies and methods to cater to the students' learning needs and support a conductive learning environment. The VARK [an acronym for visual (V), aural (A), read/write (R) and kinesthetic (K)] instrument is a useful model to assess learning styles. The aim of this study was to use the VARK questionnaire to determine the learning styles of pre-clinical medical students in order to compare the perceived and assessed learning style preferences, assess gender differences in learning style preferences, and determine whether any relationships exists between awareness of learning styles and academic grades, age, gender and learning modality. The VARK questionnaire was administered to pre-clinical students taking a variety of courses in the first three years of the undergraduate MB BS degree programme at the Faculty of Medical Sciences, The University of the West Indies, Cave Hill Campus, Barbados in 2014. The majority of the students were multimodal learners with no differences observed between males (59.5%) and females (60.0%), with tetramodal being the most common. Read/write (33.8%) followed by kinesthetic (32.5%) were the most common learning style preferences. The sensory modality preference for females was read/write (34.2%) and for males it was kinesthetic (40.5%). Significant differences were observed between the perceived and assessed learning style preferences with a majority of visual and read/write learners correctly matching their perceived to their actual learning styles. Awareness of learning styles was associated with learning modality but not with academic performance, age or gender. Overall, 60.7% of high achievers used multimodal learning compared to 56.9% low achievers. The findings from this study indicated that the VARK tool was useful in gathering information about different learning styles, and might assist educators in designing blended teaching

  8. Animal models for liver metastases of colorectal cancer: research review of preclinical studies in rodents.

    PubMed

    de Jong, Gabie M; Aarts, Frits; Hendriks, Thijs; Boerman, Otto C; Bleichrodt, Robert P

    2009-06-01

    Liver metastases of colorectal carcinoma occur in about 50-60% of patients. To improve survival of these patients, there is an urgent need for new treatment strategies. For this purpose, the availability of a preclinical model to develop and test such treatments is mandatory. An ideal animal model for studying liver metastases of colorectal origin should mimic all aspects of the metastatic development in humans and be practical, predictable, and optimal in terms of ethical considerations. Thus far, no model has been developed which satisfies all these conditions. As a consequence, choosing an animal model for the study of liver metastases requires compromises and choices about the necessary characteristics that depend on the purpose of the intended experiments. This overview addresses the advantages and disadvantages of different animal models used for research on experimental liver metastases of colorectal origin. Based on data available in literature, we conclude that heterotopic injection of undifferentiated syngeneic tumor cells in immunocompetent rodents covers most of the desired characteristics. Both subcapsular as well as intraportal injection will yield suitable models and the eventual choice will depend on the aim of the study.

  9. Reference values of clinical pathology parameters in cynomolgus monkeys (Macaca fascicularis) used in preclinical studies

    PubMed Central

    Park, Hyun-Kyu; Cho, Jae-Woo; Lee, Byoung-Seok; Park, Heejin; Han, Ji-Seok; Yang, Mi-Jin; Im, Wan-Jung; Park, Do-Yong; Kim, Woo-Jin; Han, Su-Cheol

    2016-01-01

    Nonhuman primates are increasingly used in biomedical research since they are highly homologous to humans compared to other rodent animals. However, there is limited reliable reference data of the clinical pathology parameters in cynomolgus monkeys, and in particular, only some coagulation and urinalysis parameters have been reported. Here, we reported the reference data of clinical chemical, hematological, blood coagulation, and urinalysis parameters in cynomolgus monkeys. The role of sex differences was analyzed and several parameters (including hematocrit, hemoglobin, red blood cell, blood urea nitrogen, total bilirubin, alkaline phosphatase, creatinine kinase, gamma-glutamyl tranferase, and lactate dehydrogenase) significantly differed between male and female subjects. In addition, compared to previous study results, lactate dehydrogenase, creatinine kinase, and aspartate aminotransferase showed significant variation. Interstudy differences could be affected by several factors, including age, sex, geographic origin, presence/absence of anesthetics, fasting state, and the analytical methods used. Therefore, it is important to deliberate with the overall reference indices. In conclusion, the current study provides a comprehensive and updated reference data of the clinical pathology parameters in cynomolgus monkeys and provides improved assessment criteria for evaluating preclinical studies or biomedical research. PMID:27382375

  10. HDL and Atherosclerosis Regression: Evidence from Pre-clinical and Clinical Studies

    PubMed Central

    Feig, Jonathan E.; Hewing, Bernd; Smith, Jonathan D.; Hazen, Stanley L.; Fisher, Edward A.

    2014-01-01

    High density lipoprotein particles (HDL) transport, among other molecules, cholesterol (HDL-C). In epidemiologic studies, plasma HDL-C levels have an inverse relationship to the risk of atherosclerotic cardiovascular disease (CVD). It has been assumed that this reflects the protective functions of HDL, which include their ability to promote cholesterol efflux. Yet, a number of recent pharmacological and genetic studies have failed to demonstrate that increased plasma levels of HDL-C resulted in decreased CVD risk, giving rise to a controversy over whether plasma levels of HDL-C reflect HDL function, or that HDL is even as protective as assumed. On balance, the evidence from pre-clinical and (limited) clinical studies show that HDL can promote the regression of atherosclerosis when the levels of functional particles are increased from endogenous or exogenous sources. The data show that regression results from a combination of reduced plaque lipid and macrophage contents, as well as from a reduction in its inflammatory state. While more research will be needed on basic mechanisms and to establish that these changes translate clinically to reduced CVD events, that HDL can regress plaques suggests that the recent trial failures do not eliminate HDL from consideration as an atheroprotective agent, but emphasizes the important distinction between HDL function and plasma levels of HDL-C. PMID:24385513

  11. Benznidazole Extended-Release Tablets for Improved Treatment of Chagas Disease: Preclinical Pharmacokinetic Study

    PubMed Central

    Campos, Michel Leandro; Rosa, Talita Atanazio; Padilha, Elias Carvalho; Alzate, Alejandro Henao; Rolim, Larissa Araújo; Rolim-Neto, Pedro José

    2016-01-01

    Benznidazole (BNZ) is the first-line drug for the treatment of Chagas disease. The drug is available in the form of immediate-release tablets for 100-mg (adult) and 12.5-mg (pediatric) doses. The drug is administered two or three times daily for 60 days. The high frequency of daily administrations and the long period of treatment are factors that significantly contribute to the abandonment of therapy, affecting therapeutic success. Accordingly, this study aimed to evaluate the preclinical pharmacokinetics of BNZ administered as extended-release tablets (200-mg dose) formulated with different types of polymers (hydroxypropyl methylcellulose K4M and K100M), compared to the tablets currently available. The studies were conducted with rabbits, and BNZ quantification was performed in plasma and urine by ultraperformance liquid chromatography methods previously validated. The bioavailability of BNZ was adequate in the administration of extended-release tablets; however, with the administration of the pediatric tablet, the bioavailability was lower than with other tablets, which showed that the clinical use of this formulation should be monitored. The pharmacokinetic parameters demonstrated that the extended-release tablets prolonged drug release from the pharmaceutical matrix and provided an increase in the maintenance of the drug concentration in vivo, which would allow the frequency of administration to be reduced. Thus, a relative bioavailability study in humans will be planned for implementation of a new product for the treatment of Chagas disease. PMID:26883698

  12. Benznidazole Extended-Release Tablets for Improved Treatment of Chagas Disease: Preclinical Pharmacokinetic Study.

    PubMed

    Davanço, Marcelo Gomes; Campos, Michel Leandro; Rosa, Talita Atanazio; Padilha, Elias Carvalho; Alzate, Alejandro Henao; Rolim, Larissa Araújo; Rolim-Neto, Pedro José; Peccinini, Rosângela Gonçalves

    2016-04-01

    Benznidazole (BNZ) is the first-line drug for the treatment of Chagas disease. The drug is available in the form of immediate-release tablets for 100-mg (adult) and 12.5-mg (pediatric) doses. The drug is administered two or three times daily for 60 days. The high frequency of daily administrations and the long period of treatment are factors that significantly contribute to the abandonment of therapy, affecting therapeutic success. Accordingly, this study aimed to evaluate the preclinical pharmacokinetics of BNZ administered as extended-release tablets (200-mg dose) formulated with different types of polymers (hydroxypropyl methylcellulose K4M and K100M), compared to the tablets currently available. The studies were conducted with rabbits, and BNZ quantification was performed in plasma and urine by ultraperformance liquid chromatography methods previously validated. The bioavailability of BNZ was adequate in the administration of extended-release tablets; however, with the administration of the pediatric tablet, the bioavailability was lower than with other tablets, which showed that the clinical use of this formulation should be monitored. The pharmacokinetic parameters demonstrated that the extended-release tablets prolonged drug release from the pharmaceutical matrix and provided an increase in the maintenance of the drug concentrationin vivo, which would allow the frequency of administration to be reduced. Thus, a relative bioavailability study in humans will be planned for implementation of a new product for the treatment of Chagas disease.

  13. Examination performances of German and international medical students in the preclinical studying-term--a descriptive study.

    PubMed

    Huhn, D; Resch, F; Duelli, R; Möltner, A; Huber, J; Karimian Jazi, K; Amr, A; Eckart, W; Herzog, W; Nikendei, C

    2014-01-01

    Medical students with a migration background face several specific problems during their studies. International surveys show first indications that this group of students performs worse in written, oral or practical exams. However, so far, nothing is known about the performance of international students in written pre-clinical tests as well as in pre-clinical State Examinations for German-speaking countries. A descriptive, retrospective analysis of the exam performances of medical students in the pre-clinical part of their studies was conducted at the Faculty of Medicine of Heidelberg in for the year 2012. Performance in written tests of the final exams in the second (N=276), third (N=292) and fourth semester (N=285) were compared between German students, students from EU countries and students from non-EU countries. Same comparison was drawn for the performance in the oral exam of the First State Examination in the period from 2009 - 2012 (N=1137). German students performed significantly better than students with a non-EU migration background both in all written exams and in the oral State Examination (all p<.05). The performance of students with an EU migration background was significantly better than that of students with a non-EU background in the written exam at the end of the third and fourth semester (p<.05). Furthermore, German students completed the oral exam of the First State Examination significantly earlier than students with a non-EU migration background (<.01). Due to its poorer performance in written and oral examinations and its simultaneously longer duration of study, the group of non-German medical students with a country of origin outside of the European Union has to be seen as a high-risk group among students with a migration background. For this group, there is an urgent need for early support to prepare for written and oral examinations.

  14. Examination performances of German and international medical students in the preclinical studying-term – A descriptive study

    PubMed Central

    Huhn, D.; Resch, F.; Duelli, R.; Möltner, A.; Huber, J.; Karimian Jazi, K.; Amr, A.; Eckart, W.; Herzog, W.; Nikendei, C.

    2014-01-01

    Introduction: Medical students with a migration background face several specific problems during their studies. International surveys show first indications that this group of students performs worse in written, oral or practical exams. However, so far, nothing is known about the performance of international students in written pre-clinical tests as well as in pre-clinical State Examinations for German-speaking countries. Method: A descriptive, retrospective analysis of the exam performances of medical students in the pre-clinical part of their studies was conducted at the Faculty of Medicine of Heidelberg in for the year 2012. Performance in written tests of the final exams in the second (N=276), third (N=292) and fourth semester (N=285) were compared between German students, students from EU countries and students from non-EU countries. Same comparison was drawn for the performance in the oral exam of the First State Examination in the period from 2009 - 2012 (N=1137). Results: German students performed significantly better than students with a non-EU migration background both in all written exams and in the oral State Examination (all p<.05). The performance of students with an EU migration background was significantly better than that of students with a non-EU background in the written exam at the end of the third and fourth semester (p<.05). Furthermore, German students completed the oral exam of the First State Examination significantly earlier than students with a non-EU migration background (<.01). Discussion: Due to its poorer performance in written and oral examinations and its simultaneously longer duration of study, the group of non-German medical students with a country of origin outside of the European Union has to be seen as a high-risk group among students with a migration background. For this group, there is an urgent need for early support to prepare for written and oral examinations. PMID:25228931

  15. Mean Sojourn Time of Preclinical Gastric Cancer in Korean Men: A Retrospective Observational Study

    PubMed Central

    Bae, Jong-Myon; Shin, Sang Yop; Kim, Eun Hee

    2014-01-01

    Objectives: This retrospective cohort study aimed to estimate the mean sojourn time (MST) of preclinical gastric cancer in Korean men. Methods: The subjects consisted of voluntary male screenees aged 40 to 69 years who underwent subsequent screening gastroscopies after testing negative at a baseline screening performed between January 2007 and December 2011. A new case was defined if gastric cancer cells were present in the biopsy specimens obtained from gastroscopy. The follow-up period was calculated as the number of person-years between the date of baseline screening gastroscopy and positive findings at a subsequent screening. The MST was calculated using transition rates of gastric cancer to determine the best screening interval. Results: Of the 171 979 voluntary male screenees, 61 688 (36%) underwent subsequent screening gastroscopies between January 2007 and December 2011. A total of 91 incident cases were found during 19 598 598 person-years of follow-up. The MST of gastric cancer was 2.37 years (95% confidence intervals, 1.92 to 2.96), and those aged 40 to 49 years had a shorter MST than those 50 to 69 years did. Conclusions: These findings support the 2-year interval of screening recommended by the nationwide gastric cancer screening program in Korea. Further studies for the age-specific MST among women are needed. PMID:25139166

  16. Videotaped Feedback Method to Enhance Learning in Preclinical Operative Dentistry: An Experimental Study.

    PubMed

    Shah, Dipali Yogesh; Dadpe, Ashwini Manish; Kalra, Dheeraj Deepak; Garcha, Vikram P

    2015-12-01

    The aim of this study was to investigate if a videotaped feedback method enhanced teaching and learning outcomes in a preclinical operative laboratory setting for novice learners. In 2013, 60 dental students at a dental school in India were randomly assigned to two groups: control (n=30) and experimental (n=30). The control group prepared a Class II tooth preparation for amalgam after receiving a video demonstration of the exercise. The experimental group received the same video demonstration as the control group, but they also participated in a discussion and analysis of the control groups' videotaped performance and then performed the same exercise. The self-evaluation scores (SS) and examiner evaluation scores (ES) of the two groups were compared using the unpaired t-test. The experimental group also used a five-point Likert scale to rate each item on the feedback form. The means of SS (13.65±2.43) and ES (14.75±1.97) of the experimental group were statistically higher than the means of SS (11.55±2.09) and ES (11.60±1.82) of the control group. Most students in the experimental group perceived that this technique enhanced their learning experience. Within the limits of this study, the videotaped feedback using both ideal and non-ideal examples enhanced the students' performance.

  17. Regenerative medicine in Huntington's disease: Strengths and weaknesses of preclinical studies.

    PubMed

    Tartaglione, A M; Popoli, P; Calamandrei, G

    2017-02-20

    Huntington's disease (HD) is an inherited neurodegenerative disorder, characterized by impairment in motor, cognitive and psychiatric domains. Currently, there is no specific therapy to act on the onset or progression of HD. The marked neuronal death observed in HD is a main argument in favour of stem cells (SCs) transplantation as a promising therapeutic perspective to replace the population of lost neurons and restore the functionality of the damaged circuitry. The availability of rodent models of HD encourages the investigation of the restorative potential of SCs transplantation longitudinally. However, the results of preclinical studies on SCs therapy in HD are so far largely inconsistent; this hampers the individuation of the more appropriate model and precludes the comparative analysis of transplant efficacy on behavioural end points. Thus, this review will describe the state of the art of in vivo research on SCs therapy in HD, analysing in a translational perspective the strengths and weaknesses of animal studies investigating the therapeutic potential of cell transplantation on HD progression.

  18. Preclinical endodontic teaching

    PubMed Central

    Narayanaraopeta, Udaya; AlShwaimi, Emad

    2015-01-01

    Objectives: To provide an overview of the general curricula in preclinical endodontic training from 6 established dental schools in Saudi Arabia. Methods: This study was conducted in January 2014 including only schools that had more than 2 groups of student graduates prior to the study. We included 2 dental schools from the Central region, one from Qassim region, one from the Makkah region (west), one from Abha region (south west), and one from the eastern region. An internet-based questionnaire was sent to the course directors of preclinical endodontics department of the 6 schools. The survey comprised 20 questions that examined various aspects of preclinical endodontics. Results: It was demonstrated that a significant number of faculty members had Doctor of Philosophy (PhD) degrees (n=21), Master’s degrees (n=15), and Saudi board certifications (n=8). We determined that the faculty to student ratio varied from 2:1 to 8: 1 among the colleges. The participating dental schools were found to teach the Step Back, as well as the Step Down techniques for root canal preparation. Five of the 6 schools implemented the use of nickel titanium rotary instruments. All dental schools predominantly used radiographs as the means of the working length determination. Conclusion: The curriculum for preclinical endodontics in Saudi Arabia is comparable to that followed in most European countries. A more comprehensive survey is needed that would involve more schools to formulate generalized guidelines for preclinical endodontic training in Saudi Arabia. PMID:25630011

  19. Theoretical study of bone sialoprotein in bone biomineralization.

    PubMed

    Yang, Yang; Mkhonto, Donald; Cui, Qiang; Sahai, Nita

    2011-01-01

    Bone sialoprotein (BSP) is an acidic, non-collagenous protein specific to bone proposed previously to promote hydroxyapatite (HAP) nucleation and modulate HAP nanocrystal growth. Specifically, two phosphorylated acidic amino acid sequences in BSP, highly conserved across several vertebrates, are the proposed active sites. We selected one of these sites, i.e. (Sp)(2)E(8), where Sp represents a phosphoserine as a model peptide to study the role of BSP. We used molecular dynamics simulations to determine whether an α-helix or a random coil peptide conformation promotes templated HAP nucleation. A bioinformatics method helps infer preferential crystal growth directions by predicting the likely peptide conformations adsorbed on the (001), (100), and (110) crystal faces of HAP. Results suggest that, independent of conformation, no stable nucleating template is formed and, thus, the ion distributions in the vicinity of the peptide that eventually lead to a stable nucleus start out with disordered arrangements of ions. When adsorbed on all three faces, the Sp residues bind strongly regardless of the peptide conformation, and the Glu residues show different propensities to form helical conformations. The lack of geometrical templating between the peptide residues and all HAP surface sites indicates that adsorption and subsequent crystal growth modulation may be structurally nonspecific. Copyright © 2011 S. Karger AG, Basel.

  20. Autosomal Dominant Alzheimer Disease: A Unique Resource to Study CSF Biomarker Changes in Preclinical AD

    PubMed Central

    Schindler, Suzanne Elizabeth; Fagan, Anne M.

    2015-01-01

    Our understanding of the pathogenesis of Alzheimer disease (AD) has been greatly influenced by investigation of rare families with autosomal dominant mutations that cause early onset AD. Mutations in the genes coding for amyloid precursor protein (APP), presenilin 1 (PSEN-1), and presenilin 2 (PSEN-2) cause over-production of the amyloid-β peptide (Aβ) leading to early deposition of Aβ in the brain, which in turn is hypothesized to initiate a cascade of processes, resulting in neuronal death, cognitive decline, and eventual dementia. Studies of cerebrospinal fluid (CSF) from individuals with the common form of AD, late-onset AD (LOAD), have revealed that low CSF Aβ42 and high CSF tau are associated with AD brain pathology. Herein, we review the literature on CSF biomarkers in autosomal dominant AD (ADAD), which has contributed to a detailed road map of AD pathogenesis, especially during the preclinical period, prior to the appearance of any cognitive symptoms. Current drug trials are also taking advantage of the unique characteristics of ADAD and utilizing CSF biomarkers to accelerate development of effective therapies for AD. PMID:26175713

  1. Electrophysiological Mechanisms of Brugada Syndrome: Insights from Pre-clinical and Clinical Studies

    PubMed Central

    Tse, Gary; Liu, Tong; Li, Ka H. C.; Laxton, Victoria; Chan, Yin W. F.; Keung, Wendy; Li, Ronald A.; Yan, Bryan P.

    2016-01-01

    Brugada syndrome (BrS), is a primary electrical disorder predisposing affected individuals to sudden cardiac death via the development of ventricular tachycardia and fibrillation (VT/VF). Originally, BrS was linked to mutations in the SCN5A, which encodes for the cardiac Na+ channel. To date, variants in 19 genes have been implicated in this condition, with 11, 5, 3, and 1 genes affecting the Na+, K+, Ca2+, and funny currents, respectively. Diagnosis of BrS is based on ECG criteria of coved- or saddle-shaped ST segment elevation and/or T-wave inversion with or without drug challenge. Three hypotheses based on abnormal depolarization, abnormal repolarization, and current-load-mismatch have been put forward to explain the electrophysiological mechanisms responsible for BrS. Evidence from computational modeling, pre-clinical, and clinical studies illustrates that molecular abnormalities found in BrS lead to alterations in excitation wavelength (λ), which ultimately elevates arrhythmic risk. A major challenge for clinicians in managing this condition is the difficulty in predicting the subset of patients who will suffer from life-threatening VT/VF. Several repolarization risk markers have been used thus far, but these neglect the contributions of conduction abnormalities in the form of slowing and dispersion. Indices incorporating both repolarization and conduction and based on the concept of λ have recently been proposed. These may have better predictive values than the existing markers. PMID:27803673

  2. Preclinical symptoms of major depression in very old age: a prospective longitudinal study.

    PubMed

    Berger, A K; Small, B J; Forsell, Y; Winblad, B; Bäckman, L

    1998-08-01

    The authors' goal was to examine whether individuals diagnosed as having major depression experienced greater levels of depressive symptoms and cognitive dysfunction up to 3 years before the clinical diagnosis was rendered. The study included 185 subjects 75 years old or older who participated in a population-based longitudinal survey in Stockholm. Ten of the subjects were diagnosed as depressed up to 3 years after initial screening, and these individuals were compared with the 175 subjects who were not depressed at 3-year follow-up. Depression was diagnosed according to DSM-III-R and DSM-IV criteria. Psychiatric signs and symptoms were assessed by physicians using a structured interview. Cognitive functioning was assessed with the Mini-Mental State. At the initial screening, the patients later diagnosed as depressed had a greater number of depressive symptoms, such as dysphoria and appetite disturbance, and their symptoms were also more severe than those of the nondepressed subjects. Moreover, the depressed subjects suffered from a more severe lack of interest and psychomotor disturbance and had lower Mini-Mental State scores. There are preclinical markers for individuals who will become depressed after a 3-year interval. Major depression may have a more chronic nature in very old age, in contrast to the relatively short clinical onset of depression seen in younger adults. The authors conclude that standard diagnostic instruments such as DSM-IV may have to take this lengthy course of impairment into consideration when dealing with very old adults.

  3. Preclinical study of cinobufagin as a promising anti-colorectal cancer agent

    PubMed Central

    Lu, Xing-sheng; Qiao, Yin-biao; Li, Ya; Yang, Bo; Chen, Min-bin; Xing, Chun-gen

    2017-01-01

    Here, we assessed the anti-colorectal cancer (CRC) cell activity of cinobufagin (CBG). We found that CBG exerted potent cytotoxic and anti-proliferative activity against CRC lines (HCT-116 and HT-29) and primary human CRC cells. Meanwhile, it activated apoptosis, and disrupted cell-cycle progression in the cells. At the signaling level, CBG treatment in CRC cells provoked endoplasmic reticulum stress (ER stress), the latter was evidenced by caspase-12 activation, CHOP expression, as well as PERK and IRE1 phosphorylations. Contrarily, the ER stress inhibitor salubrinal, the caspase-12 inhibitor and CHOP shRNA remarkably attenuated CBG-induced CRC cell death and apoptosis. Further, CBG in-activated mammalian target or rapamycin complex 1 (mTORC1), which appeared responsible for proliferation inhibition in CRC cells. Introduction of a constitutively-active S6K1 (“ca-S6K1”) restored proliferation of CBG-treated CRC cells. Finally, CBG intraperitoneal injection suppressed HCT-116 xenograft tumor growth in the nude mice. CHOP upregulation and mTORC1 in-activation were also noticed in CBG-treated HCT-116 tumors. The results of this preclinical study suggest that CBG could be tested as promising anti-CRC agent. PMID:27894091

  4. Bosutinib : a review of preclinical and clinical studies in chronic myelogenous leukemia.

    PubMed

    Rusconi, Francesca; Piazza, Rocco; Vagge, Elisabetta; Gambacorti-Passerini, Carlo

    2014-04-01

    Chronic myeloid leukemia (CML) is a hematopoietic stem cell disease. It is characterized by a Bcr-Abl (breakpoint cluster region-Abelson leukemia virus) tyrosine kinase fusion protein produced from the Philadelphia (Ph) chromosome. The tyrosine kinase inhibitor (TKI) imatinib was the first targeted therapy licensed for patients with chronic-phase CML. In recent years, many other TKIs have been approved for the treatment of patients with CML. For this reason, the choice of the best strategy treatment has become increasingly complex. Bosutinib , a dual Src/Abl kinase inhibitor, has shown potent activity against CML and it has been approved by the US FDA for the treatment of chronic, accelerated or blast-phase Ph+ CML. This review was conducted to describe the preclinical and clinical activity of bosutinib and the safety and tolerability of the drug in the treatment of CML. Included studies were identified through a search of electronic databases in July 2013 and relevant conference proceedings. Imatinib continues to represent the treatment of choice for CML. However, some patients develop resistance or intolerance to imatinib or to other second-generation TKIs. Bosutinib shows a good therapeutic activity with a benign safety profile, no cardiovascular toxicity, and offers an important therapeutic addition to the armamentarium that physicians can use against resistant CML.

  5. A Patient-Derived Xenograft Model of Parameningeal Embryonal Rhabdomyosarcoma for Preclinical Studies

    PubMed Central

    Hooper, Jody E.; Cantor, Emma L.; Ehlen, Macgregor S.; Banerjee, Avirup; Malempati, Suman; Stenzel, Peter; Woltjer, Randy L.; Gandour-Edwards, Regina; Goodwin, Neal C.; Yang, Yan; Kaur, Pali; Bult, Carol J.; Airhart, Susan D.; Keller, Charles

    2015-01-01

    Embryonal rhabdomyosarcoma (eRMS) is one of the most common soft tissue sarcomas in children and adolescents. Parameningeal eRMS is a variant that is often more difficult to treat than eRMS occurring at other sites. A 14-year-old female with persistent headaches and rapid weight loss was diagnosed with parameningeal eRMS. She progressed and died despite chemotherapy with vincristine, actinomycin-D, and cyclophosphamide plus 50.4 Gy radiation therapy to the primary tumor site. Tumor specimens were acquired by rapid autopsy and tumor tissue was transplanted into immunodeficient mice to create a patient-derived xenograft (PDX) animal model. As autopsy specimens had an ALK R1181C mutation, PDX tumor bearing animals were treated with the pan-kinase inhibitor lestaurtinib but demonstrated no decrease in tumor growth, suggesting that single agent kinase inhibitor therapy may be insufficient in similar cases. This unique parameningeal eRMS PDX model is publicly available for preclinical study. PMID:26696773

  6. A Patient-Derived Xenograft Model of Parameningeal Embryonal Rhabdomyosarcoma for Preclinical Studies.

    PubMed

    Hooper, Jody E; Cantor, Emma L; Ehlen, Macgregor S; Banerjee, Avirup; Malempati, Suman; Stenzel, Peter; Woltjer, Randy L; Gandour-Edwards, Regina; Goodwin, Neal C; Yang, Yan; Kaur, Pali; Bult, Carol J; Airhart, Susan D; Keller, Charles

    2015-01-01

    Embryonal rhabdomyosarcoma (eRMS) is one of the most common soft tissue sarcomas in children and adolescents. Parameningeal eRMS is a variant that is often more difficult to treat than eRMS occurring at other sites. A 14-year-old female with persistent headaches and rapid weight loss was diagnosed with parameningeal eRMS. She progressed and died despite chemotherapy with vincristine, actinomycin-D, and cyclophosphamide plus 50.4 Gy radiation therapy to the primary tumor site. Tumor specimens were acquired by rapid autopsy and tumor tissue was transplanted into immunodeficient mice to create a patient-derived xenograft (PDX) animal model. As autopsy specimens had an ALK R1181C mutation, PDX tumor bearing animals were treated with the pan-kinase inhibitor lestaurtinib but demonstrated no decrease in tumor growth, suggesting that single agent kinase inhibitor therapy may be insufficient in similar cases. This unique parameningeal eRMS PDX model is publicly available for preclinical study.

  7. Incorporating iPads into a preclinical curriculum: a pilot study.

    PubMed

    George, Paul; Dumenco, Luba; Doyle, Richard; Dollase, Richard

    2013-01-01

    The incorporation of technology into medical education is critical for learners. Little is known about the effect of integrating iPad technology into undergraduate medical education. We introduced iPads into the first-year curriculum in 2011-2012. We aimed to evaluate students' use of, and attitudes toward, the iPad. We administered two surveys to students during the 2011-2012 academic year. Additionally, we conducted focus groups to further evaluate the effectiveness of iPad integration into the curriculum. Survey data reflect mixed attitudes toward the use of the iPad in the preclinical curriculum. While a vast majority of students agree "the iPad has value in the medical curriculum" (79% in the first survey; 65% in the second survey), there was a decrease over time in the view that "the iPad is a positive addition to the curriculum" (75% in the first survey; 49% in the second survey). Focus group data indicate students appreciate certain aspects of iPad use in the curriculum, including improved curriculum interactivity, but the majority believe it cannot replace printed handouts at this time. The iPad provides some benefits in undergraduate medical education. More studies are necessary to determine how the iPad is best incorporated into medical education.

  8. Preclinical studies of a specific PPARγ modulator in the control of skin inflammation.

    PubMed

    Mastrofrancesco, Arianna; Kovacs, Daniela; Sarra, Massimiliano; Bastonini, Emanuela; Cardinali, Giorgia; Aspite, Nicaela; Camera, Emanuela; Chavatte, Philippe; Desreumaux, Pierre; Monteleone, Giovanni; Picardo, Mauro

    2014-04-01

    Peroxisome proliferator-activated receptor γ (PPARγ) antagonizes inflammatory signals by interfering with NF-κB nuclear translocation. Consistently, PPARγ agonists have been proposed in various inflammatory skin disorders, but their wide use has been limited by severe side effects. Classes of compounds with specific PPARγ agonism have been designed to selectively target inflammatory pathways. Among these compounds, GED-0507-34L has been developed and recently used in phase II clinical trials for inflammatory bowel diseases. This study was aimed at assessing the role of GED-0507-34L in preclinical models of inflammatory skin diseases. The compound modulated PPARγ function and suppressed the inflammatory process inhibiting NF-κB nuclear translocation with the consequent reduction of inflammatory cytokines expression, such as IL-6, IL-8, IL-12, IL-21, IL-23, tumor necrosis factor-α (TNF-α), and cyclooxygenase-2 (COX-2) in normal human keratinocytes and lymphocytes treated with lipopolysaccharide (LPS) or TNF-α. Moreover, an altered proliferation and expression of differentiation markers induced by TNF-α were also counteracted. In psoriasis-like skin lesions elicited in mice by IL-21, topical application of GED-0507-34L reduced cellular infiltrate and epidermal hyperplasia, normalizing the differentiation process. The results indicate that GED-0507-34L possesses anti-inflammatory properties useful for the management of patients with inflammatory skin diseases including psoriasis. Phase I trial on patients is ongoing.

  9. Selective small molecule angiotensin II type 2 receptor antagonists for neuropathic pain: preclinical and clinical studies.

    PubMed

    Smith, Maree T; Anand, Praveen; Rice, Andrew S C

    2016-02-01

    Neuropathic pain affects up to 10% of the general population, but drug treatments recommended for the treatment of neuropathic pain are associated with modest efficacy and/or produce dose-limiting side effects. Hence, neuropathic pain is an unmet medical need. In the past 2 decades, research on the pathobiology of neuropathic pain has revealed many novel pain targets for use in analgesic drug discovery programs. However, these efforts have been largely unsuccessful as molecules that showed promising pain relief in rodent models of neuropathic pain generally failed to produce analgesia in early phase clinical trials in patients with neuropathic pain. One notable exception is the angiotensin II type 2 (AT2) receptor that has clinical validity on the basis of a successful double-blind, randomized, placebo-controlled, clinical trial of EMA401, a highly selective, orally active, peripherally restricted AT2 receptor antagonist in patients with postherpetic neuralgia. In this study, we review research to date on target validation, efficacy, and mode of action of small molecule AT2 receptor antagonists in rodent models of peripheral neuropathic pain and in cultured human sensory neurons, the preclinical pharmacokinetics of these compounds, and the outcome of the above clinical trial.

  10. Robust modeling in screening studies: estimation of sensitivity and preclinical sojourn time distribution.

    PubMed

    Shen, Yu; Zelen, Marvin

    2005-10-01

    In early-detection clinical trials, quantities such as the sensitivity of the screening modality and the preclinical duration of the disease are important to describe the natural history of the disease and its interaction with a screening program. Assume that the schedule of a screening program is periodic and that the sojourn time in the preclinical state has a piecewise density function. Modeling the preclinical sojourn time distribution as a piecewise density function results in robust estimation of the distribution function. Our aim is to estimate the piecewise density function and the examination sensitivity using both generalized least squares and maximum likelihood methods. We carried out extensive simulations to evaluate the performance of the methods of estimation. The different estimation methods provide complimentary tools to obtain the unknown parameters. The methods are applied to three breast cancer early-detection trials.

  11. Preclinical safety and effectiveness studies of ultrasonic propulsion of kidney stones

    PubMed Central

    Harper, Jonathan D.; Dunmire, Barbrina; Wang, Yak-Nam; Simon, Julianna C.; Liggitt, H. Denny; Paun, Marla; Cunitz, Bryan W.; Starr, Frank; Bailey, Michael R.; Penniston, Kristina; Lee, Franklin Chong-Ho; Hsi, Ryan S.; Sorensen, Mathew D.

    2014-01-01

    Objective To provide an update on a research device to ultrasonically reposition kidney stones transcutaneously. This paper reports preclinical safety and effectiveness studies, survival data, modifications of the system, and testing in a stone-forming porcine model. These data formed the basis for regulatory approval to test the device in humans. Materials and Methods The ultrasound burst was shortened to 50ms from previous investigations with 1s bursts. Focused ultrasound was used to expel 2–5mm calcium oxalate monohydrate stones placed ureteroscopically in five pigs. Additionally, de novo stones were imaged and repositioned in a stone-forming porcine model. Acute safety studies were performed targeting two kidneys (6 sites) and three pancreases (8 sites). Survival studies followed 10 animals for one week after simulated treatment. Serum and urine analyses were performed and tissues were evaluated histologically. Results All ureteroscopically-implanted stones (6/6) were repositioned out of the kidney in 14 ± 8 minutes with 13 ± 6 bursts. On average, three bursts moved a stone more than 4mm and collectively accounted for the majority of relocation. Stones (3mm) were detected and repositioned in the 200-kg stone-forming model. No injury was detected in the acute or survival studies. Conclusions Ultrasonic propulsion is safe and effective in the porcine model. Stones were expelled from the kidney. De novo stones formed in a large porcine model were repositioned. No adverse effects were identified with the acute studies directly targeting kidney or pancreatic tissue or during the survival studies indicating no evidence of delayed tissue injury. PMID:24975708

  12. Preclinical safety and effectiveness studies of ultrasonic propulsion of kidney stones.

    PubMed

    Harper, Jonathan D; Dunmire, Barbrina; Wang, Yak-Nam; Simon, Julianna C; Liggitt, Denny; Paun, Marla; Cunitz, Bryan W; Starr, Frank; Bailey, Michael R; Penniston, Kristina L; Lee, Franklin C; Hsi, Ryan S; Sorensen, Mathew D

    2014-08-01

    To provide an update on a research device to ultrasonically reposition kidney stones transcutaneously. This article reports preclinical safety and effectiveness studies, survival data, modifications of the system, and testing in a stone-forming porcine model. These data formed the basis for regulatory approval to test the device in humans. The ultrasound burst was shortened to 50 ms from previous investigations with 1-s bursts. Focused ultrasound was used to expel 2- to 5-mm calcium oxalate monohydrate stones placed ureteroscopically in 5 pigs. Additionally, de novo stones were imaged and repositioned in a stone-forming porcine model. Acute safety studies were performed targeting 2 kidneys (6 sites) and 3 pancreases (8 sites). Survival studies followed 10 animals for 1 week after simulated treatment. Serum and urine analyses were performed, and tissues were evaluated histologically. All ureteroscopically implanted stones (6/6) were repositioned out of the kidney in 14 ± 8 minutes with 13 ± 6 bursts. On average, 3 bursts moved a stone more than 4 mm and collectively accounted for the majority of relocation. Stones (3 mm) were detected and repositioned in the 200-kg stone-forming model. No injury was detected in the acute or survival studies. Ultrasonic propulsion is safe and effective in the porcine model. Stones were expelled from the kidney. De novo stones formed in a large porcine model were repositioned. No adverse effects were identified with the acute studies directly targeting kidney or pancreatic tissue or during the survival studies indicating no evidence of delayed tissue injury. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Designing More Efficient Preclinical Experiments: A Simulation Study in Chemotherapy-Induced Myelosupression.

    PubMed

    Martin, Emma C; Aarons, Leon; Yates, James W T

    2016-03-01

    A new more efficient preclinical study design (referred to as a compact design) is proposed that removes the need for satellite animals for the collection of toxicokinetic (TK) data by sampling from the main study animals, taking no more than one sample in 24 h to build up a full profile over the course of the study. The compact design's performance was tested with a simulation study, using an example of chemotherapy-induced myelosupression in rats. Data sets were simulated from a model based on available data, following both the compact design and a traditional design using satellite animals, with 100 studies being simulated for each. The effect of the compact design on parameter and variance estimates for the TK and neutrophil models were investigated, as well as the potential effect of interoccasion variability (IOV). The compact design performed equally as well as the traditional design, and had little impact on parameter or variation estimates, indicating that it would be a suitable alternative to traditional satellite designs while reducing the number of animals required. When IOV was present but not accounted for during the TK analysis some parameter estimates were biased and interindividual variation and residual errors inflated; this was reduced by allowing for IOV in the analysis. Using the compact design removes the need for a satellite group, reducing the number of animals required, without affecting the ability to model the data. If large IOV is suspected, caution should be exercised to avoid parameter estimation bias, and inflation of variability and residual error.

  14. Stem Cell Therapies for Knee Cartilage Repair: The Current Status of Preclinical and Clinical Studies

    PubMed Central

    Anderson, John A.; Little, Dianne; Toth, Alison P.; Moorman, Claude T.; Tucker, Bradford S.; Ciccotti, Michael G.; Guilak, Farshid

    2014-01-01

    Background Articular cartilage damage of the knee is common, causing significant morbidity worldwide. Many adult tissues contain cells that are able to differentiate into multiple cell types, including chondrocytes. These stem cells have gained significant attention over the past decade and may become frontline management for cartilage defects in the very near future. Purpose The role of stem cells in the treatment of knee osteochondral defects was reviewed. Recent animal and clinical studies were reviewed to determine the benefits and potential outcomes of using stem cells for cartilage defects. Study Design Literature review. Methods A PubMed search was undertaken. The key phrase “stem cells and knee” was used. The search included reviews and original articles over an unlimited time period. From this search, articles outlining animal and clinical trials were selected. A search of current clinical trials in progress was performed on the clinicaltrials.gov website, and “stem cells and knee” was used as the search phrase. Results Stem cells have been used in many recent in vitro and animal studies. A number of cell-based approaches for cartilage repair have progressed from preclinical animal studies into clinical trials. Conclusion The use of stem cells for the treatment of cartilage defects is increasing in animal and clinical studies. Methods of delivery of stem cells to the knee’s cartilage vary from direct injection to implantation with scaffolds. While these approaches are highly promising, there is currently limited evidence of a direct clinical benefit, and further research is required to assess the overall outcome of stem cell therapies for knee cartilage repair. PMID:24220016

  15. Stem cell therapies for knee cartilage repair: the current status of preclinical and clinical studies.

    PubMed

    Anderson, John A; Little, Dianne; Toth, Alison P; Moorman, Claude T; Tucker, Bradford S; Ciccotti, Michael G; Guilak, Farshid

    2014-09-01

    Articular cartilage damage of the knee is common, causing significant morbidity worldwide. Many adult tissues contain cells that are able to differentiate into multiple cell types, including chondrocytes. These stem cells have gained significant attention over the past decade and may become frontline management for cartilage defects in the very near future. The role of stem cells in the treatment of knee osteochondral defects was reviewed. Recent animal and clinical studies were reviewed to determine the benefits and potential outcomes of using stem cells for cartilage defects. Literature review. A PubMed search was undertaken. The key phrase "stem cells and knee" was used. The search included reviews and original articles over an unlimited time period. From this search, articles outlining animal and clinical trials were selected. A search of current clinical trials in progress was performed on the clinicaltrials.gov website, and "stem cells and knee" was used as the search phrase. Stem cells have been used in many recent in vitro and animal studies. A number of cell-based approaches for cartilage repair have progressed from preclinical animal studies into clinical trials. The use of stem cells for the treatment of cartilage defects is increasing in animal and clinical studies. Methods of delivery of stem cells to the knee's cartilage vary from direct injection to implantation with scaffolds. While these approaches are highly promising, there is currently limited evidence of a direct clinical benefit, and further research is required to assess the overall outcome of stem cell therapies for knee cartilage repair. © 2013 The Author(s).

  16. Preclinical study and clinical trial of a novel therapeutic vaccine against multi-drug resistant tuberculosis.

    PubMed

    Okada, Masaji; Kita, Yoko; Hashimoto, Satomi; Nakatani, Hitoshi; Nishimastu, Shiho; Kioka, Yumiko; Takami, Yasuko

    2017-02-01

    [Purpose] Multi-drug resistant (MDR), Mycobacterium tuberculosis (TB) is a big problem in the world. We have developed novel TB therapeutic vaccine (HVJ-E/HSP65 DNA +IL-12 DNA). [Methods and Results] DNA vaccine expressing TB heat shock protein 65 and IL-12 was delivered by the hemagglutinating virus of Japan (HVJ)-envelope. This vaccine provided remarkable protective efficacy and strong therapeutic efficacy against MDR-TB and XDR-TB in murine models. Furthermore, this vaccine provided therapeutic efficacy of prolongation of survival time of TB infected monkeys and augmented the immune responses. Therefore, the preclinical tests were studied for clinical trial. The injection of 100 μg of the vaccine /mouse i.m. three times in two weeks induced significantly strong production of IFN-γ and IL-2. 100 μg and 200 μg DNA vaccine/mouse i.m. augmented the production of these cytokines compared with 25 μg DNA vaccine/mouse i.m.. The ratio of 100 μg pDNA to 1AU HVJ-E enhanced the production of IFN-γ and IL-2. The decrease in the number of M. tuberculosis in liver of mice was observed by the vaccination of 100μg pDNA. By using these conditions, safety pharmacology study and toxicology test is being studied in monkeys administered by GMP level DNA vaccines. By the toxicology test using monkeys, high dose GMP level vaccine/ monkey is administrated. Safety pharmacological study of repeated administration is also being investigated in GLP level. Furthermore, we have planned to do clinical phase I trial. Targets are human patients with MDR-TB. The safety and tolerability of the vaccine will be evaluated. [Conclusion and recommendations] These data indicate that our novel vaccine might be useful against tuberculosis including XDR-TB and MDR-TB for human therapeutic clinical applications.

  17. A novel preservative-free seasonal influenza vaccine safety and immune response studying in the frame of preclinical research.

    PubMed

    Sarsenbayeva, Gulbanu; Volgin, Yevgeniy; Kassenov, Markhabbat; Issagulov, Timur; Bogdanov, Nikolay; Nurpeissova, Ainur; Sagymbay, Altynay; Abitay, Ruslan; Stukova, Marina; Sansyzbay, Abylay; Khairullin, Berik

    2017-02-04

    The paper describes the results of preclinical testing of the preparation 'Vaccine allantoic split-virus inactivated against seasonal influenza'. Acute toxicity and local irritating effect, anaphylactic reactions to different antigens (vaccine and ovalbumin), delayed-type hypersensitivity to ram erythrocytes, humoral immune response in hemaggtination reaction, immunogenic activity was studied in laboratory animals of various species (mice, rats, guinea pigs). Comparative analysis of the results from testing immunogenic activity of the preparation under study and the commercial influenza vaccines was performed. The preclinical testing has demonstrated safety and immune response of the seasonal split influenza vaccine, so it may be recommended for clinical study on limited contingent of volunteers. This article is protected by copyright. All rights reserved.

  18. Miltefosine Lipid Nanocapsules for Single Dose Oral Treatment of Schistosomiasis Mansoni: A Preclinical Study

    PubMed Central

    Eissa, Maha M.; El-Moslemany, Riham M.; Ramadan, Alyaa A.; Amer, Eglal I.; El-Azzouni, Mervat Z.; El-Khordagui, Labiba K.

    2015-01-01

    Miltefosine (MFS) is an alkylphosphocholine used for the local treatment of cutaneous metastases of breast cancer and oral therapy of visceral leishmaniasis. Recently, the drug was reported in in vitro and preclinical studies to exert significant activity against different developmental stages of schistosomiasis mansoni, a widespread chronic neglected tropical disease (NTD). This justified MFS repurposing as a potential antischistosomal drug. However, five consecutive daily 20 mg/kg doses were needed for the treatment of schistosomiasis mansoni in mice. The present study aims at enhancing MFS efficacy to allow for a single 20mg/kg oral dose therapy using a nanotechnological approach based on lipid nanocapsules (LNCs) as oral nanovectors. MFS was incorporated in LNCs both as membrane-active structural alkylphospholipid component and active antischistosomal agent. MFS-LNC formulations showed high entrapment efficiency (EE%), good colloidal properties, sustained release pattern and physical stability. Further, LNCs generally decreased MFS-induced erythrocyte hemolytic activity used as surrogate indicator of membrane activity. While MFS-free LNCs exerted no antischistosomal effect, statistically significant enhancement was observed with all MFS-LNC formulations. A maximum effect was achieved with MFS-LNCs incorporating CTAB as positive charge imparting agent or oleic acid as membrane permeabilizer. Reduction of worm load, ameliorated liver pathology and extensive damage of the worm tegument provided evidence for formulation-related efficacy enhancement. Non-compartmental analysis of pharmacokinetic data obtained in rats indicated independence of antischistosomal activity on systemic drug exposure, suggesting possible gut uptake of the stable LNCs and targeting of the fluke tegument which was verified by SEM. The study findings put forward MFS-LNCs as unique oral nanovectors combining the bioactivity of MFS and biopharmaceutical advantages of LNCs, allowing targeting

  19. Miltefosine Lipid Nanocapsules for Single Dose Oral Treatment of Schistosomiasis Mansoni: A Preclinical Study.

    PubMed

    Eissa, Maha M; El-Moslemany, Riham M; Ramadan, Alyaa A; Amer, Eglal I; El-Azzouni, Mervat Z; El-Khordagui, Labiba K

    2015-01-01

    Miltefosine (MFS) is an alkylphosphocholine used for the local treatment of cutaneous metastases of breast cancer and oral therapy of visceral leishmaniasis. Recently, the drug was reported in in vitro and preclinical studies to exert significant activity against different developmental stages of schistosomiasis mansoni, a widespread chronic neglected tropical disease (NTD). This justified MFS repurposing as a potential antischistosomal drug. However, five consecutive daily 20 mg/kg doses were needed for the treatment of schistosomiasis mansoni in mice. The present study aims at enhancing MFS efficacy to allow for a single 20mg/kg oral dose therapy using a nanotechnological approach based on lipid nanocapsules (LNCs) as oral nanovectors. MFS was incorporated in LNCs both as membrane-active structural alkylphospholipid component and active antischistosomal agent. MFS-LNC formulations showed high entrapment efficiency (EE%), good colloidal properties, sustained release pattern and physical stability. Further, LNCs generally decreased MFS-induced erythrocyte hemolytic activity used as surrogate indicator of membrane activity. While MFS-free LNCs exerted no antischistosomal effect, statistically significant enhancement was observed with all MFS-LNC formulations. A maximum effect was achieved with MFS-LNCs incorporating CTAB as positive charge imparting agent or oleic acid as membrane permeabilizer. Reduction of worm load, ameliorated liver pathology and extensive damage of the worm tegument provided evidence for formulation-related efficacy enhancement. Non-compartmental analysis of pharmacokinetic data obtained in rats indicated independence of antischistosomal activity on systemic drug exposure, suggesting possible gut uptake of the stable LNCs and targeting of the fluke tegument which was verified by SEM. The study findings put forward MFS-LNCs as unique oral nanovectors combining the bioactivity of MFS and biopharmaceutical advantages of LNCs, allowing targeting

  20. Safety and Efficacy of New Sirolimus-eluting Stent Models in a Preclinical Study.

    PubMed

    Estévez-Loureiro, Rodrigo; Pérez de Prado, Armando; Pérez-Martínez, Claudia; Cuellas-Ramón, Carlos; Regueiro-Purriños, Marta; Gonzalo-Orden, José M; López-Benito, María; Molina-Crisol, María; Duocastella-Codina, Luis; Fernández-Vázquez, Felipe

    2015-12-01

    Initial preclinical studies are required during the process of improving polymers, platforms, and drug-eluting systems for new coronary stent designs. Our objective was to analyze the efficacy and safety of new drug-eluting stent models compared with a conventional stent and commercialized drug-eluting stents in an experimental model with healthy porcine coronary arteries. Sixty stents (conventional stent, new sirolimus-eluting stents: drug-eluting stents 1, 2 and 3; Cypher(®) and Xience(®)) were randomly placed in the coronary arteries of 20 Large White domestic pigs. Angiographic and histomorphometric studies were done 28 days later. The stents were implanted at a stent/artery ratio of 1.34±0.15, with no significant differences between groups. The new stents showed less late loss and angiographic restenosis than conventional stents (P=.006 and P<.001, respectively). Histologically, restenosis and neointimal area were lower with all the new platforms than with the conventional stents (P<.001 for each variable), and no differences were found vs the drug-eluting stents on the market. Safety data showed that endothelialization was lower with drug-eluting stents than with conventional stents, except for drug-eluting stent 3 (P=.084). Likewise, inflammation was lower with drug-eluting stent 3 than with other stents. The new drug-eluting stent platforms studied are associated with less restenosis than conventional stents and showed no significant differences in safety or efficacy vs commercialized drug-eluting stents. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  1. Replication Study: Discovery and preclinical validation of drug indications using compendia of public gene expression data

    PubMed Central

    Kandela, Irawati; Aird, Fraser

    2017-01-01

    In 2015, as part of the Reproducibility Project: Cancer Biology, we published a Registered Report (Kandela et al., 2015) that described how we intended to replicate selected experiments from the paper “Discovery and Preclinical Validation of Drug Indications Using Compendia of Public Gene Expression Data“ (Sirota et al., 2011). Here we report the results of those experiments. We found that cimetidine treatment in a xenograft model using A549 lung adenocarcinoma cells resulted in decreased tumor volume compared to vehicle control; however, while the effect was in the same direction as the original study (Figure 4C; Sirota et al., 2011), it was not statistically significant. Cimetidine treatment in a xenograft model using ACHN renal cell carcinoma cells did not differ from vehicle control treatment, similar to the original study (Supplemental Figure 1; Sirota et al., 2011). Doxorubicin treatment in a xenograft model using A549 lung adenocarcinoma cells did not result in a statistically significant difference compared to vehicle control despite tumor volume being reduced to levels similar to those reported in the original study (Figure 4C; Sirota et al., 2011). Finally, we report a random effects meta-analysis for each result. These meta-analyses show that the inhibition of A549 derived tumors by cimetidine resulted in a statistically significant effect, as did the inhibition of A549 derived tumors by doxorubicin. The effect of cimetidine on ACHN derived tumors was not statistically significant, as predicted. DOI: http://dx.doi.org/10.7554/eLife.17044.001 PMID:28100397

  2. Characteristics of Effective Simulation (Preclinical) Teachers as Identified by Dental Students: A Qualitative Study.

    PubMed

    McAndrew, Maureen; Mucciolo, Thomas W; Jahangiri, Leila

    2016-11-01

    The aim of this qualitative research study was to identify and categorize criteria for simulation teacher quality preferences as reported by dental students. Second-year dental students at New York University College of Dentistry in 2015 were given a two-question, open-ended survey asking what qualities they liked most and least in a simulation or preclinical teacher. Responses were collected until data saturation was reached. Key words in the responses were identified and coded based on similar relationships and then were grouped into defined categories. A total of 168 respondents out of the target group of 363 students (46.3%) provided 1,062 written comments. Three core themes-character, competence, and communication-emerged from 16 defined categories, which were validated using references from the educational literature. The theme of character encompassed eight of the defined categories (motivation, available, caring, patience, professionalism, empathy, fairness, and happiness) and accounted for 50% of the total student responses. The theme of competence comprised five categories (expertise, knowledgeable, efficient, skillful, and effective) and represented 34% of all responses. The communication theme covered the remaining three categories (feedback, approachable, and interpersonal communication) and contained 17% of the responses. Positive and negative comments in the category of motivation accounted for 11.2% of all student responses. Expertise was the next highest category with 9.3% of the responses, followed closely by 9.1% in the category of available. Among these students, the top five attributes of simulation teachers were motivation, expertise, available, caring, and feedback. While the study did not attempt to correlate these findings with improved student performance, the results can be used in the development of assessment tools for faculty and targeted faculty development programs.

  3. Electrospun vascular scaffold for cellularized small diameter blood vessels: A preclinical large animal study.

    PubMed

    Ju, Young Min; Ahn, Hyunhee; Arenas-Herrera, Juan; Kim, Cheil; Abolbashari, Mehran; Atala, Anthony; Yoo, James J; Lee, Sang Jin

    2017-09-01

    The strategy of vascular tissue engineering is to create a vascular substitute by combining autologous vascular cells with a tubular-shaped biodegradable scaffold. We have previously developed a novel electrospun bilayered vascular scaffold that provides proper biological and biomechanical properties as well as structural configuration. In this study, we investigated the clinical feasibility of a cellularized vascular scaffold in a preclinical large animal model. We fabricated the cellularized vascular construct with autologous endothelial progenitor cell (EPC)-derived endothelial cells (ECs) and smooth muscle cells (SMCs) followed by a pulsatile bioreactor preconditioning. This fully cellularized vascular construct was tested in a sheep carotid arterial interposition model. After preconditioning, confluent and mature EC and SMC layers in the scaffold were achieved. The cellularized constructs sustained the structural integrity with a high degree of graft patency without eliciting an inflammatory response over the course of the 6-month period in sheep. Moreover, the matured EC coverage on the lumen and a thick smooth muscle layer were formed at 6months after transplantation. We demonstrated that electrospun bilayered vascular scaffolds in conjunction with autologous vascular cells may be a clinically applicable alternative to traditional prosthetic vascular graft substitutes. This study demonstrates the utility of tissue engineering to provide platform technologies for rehabilitation of patients recovering from severe, devastating cardiovascular diseases. The long-term goal is to provide alternatives to vascular grafting using bioengineered blood vessels derived from an autologous cell source with a functionalized vascular scaffold. This novel bilayered vascular construct for engineering blood vessels is designed to offer "off-the-shelf" availability for clinical translation. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  4. Alterations in the Rate of Binge Ethanol Consumption: Implications for Preclinical Studies in Mice

    PubMed Central

    Linsenbardt, David N.; Boehm, Stephen L.

    2013-01-01

    The rate at which alcohol (ethanol) is consumed has direct impact on its behavioral and subjective effects. For this reason, alterations in the pattern of ethanol consumption as a function of drinking history might be critical to the development and maintenance of alcoholism. Furthermore, because pharmacological interventions aimed at disrupting the motivation to consume ethanol are dependent on the brain/plasma concentrations present when an individual is most likely to engage in consumption of this substance, characterizing temporal drinking patterns might be useful to determine the timing of such treatments. The primary goal of the present study was to evaluate alterations in the timecourse of daily binge (Drinking-in-the-dark; DID) ethanol consumption. We gave 14 daily 2 hour DID ethanol or water access sessions to male C57BL/6J (B6) mice using a state of the art volumetric drinking monitoring device. We then, primarily as a proof-of-principle, used the GABAB allosteric modulator GS39783 (GS) to determine how this compound influenced the timecourse of binge-like ethanol intake. The rate of ethanol consumption increased dramatically over sessions with the majority occurring in the first few minutes of the final session. Additionally, ethanol consumption occurring immediately following access was almost completely abolished in mice pretreated with GS; an effect which was ethanol-specific only at this early time interval. These data characterize progressive alterations in the rate of ethanol intake using the DID model and suggest that careful consideration of prior ethanol history and timing of drug administration are warranted when interpreting results of preclinical drug administration studies. PMID:23742054

  5. Preclinical studies identify novel targeted pharmacological strategies for treatment of human malignant pleural mesothelioma

    PubMed Central

    Favoni, Roberto E; Daga, Antonio; Malatesta, Paolo; Florio, Tullio

    2012-01-01

    The incidence of human malignant pleural mesothelioma (hMPM) is still increasing worldwide. hMPM prognosis is poor even if the median survival time has been slightly improved after the introduction of the up-to-date chemotherapy. Nevertheless, large phase II/III trials support the combination of platinum derivatives and pemetrexed or raltitrexed, as preferred first-line schedule. Better understanding of the molecular machinery of hMPM will lead to the design and synthesis of novel compounds targeted against pathways identified as crucial for hMPM cell proliferation and spreading. Among them, several receptors tyrosine kinase show altered activity in subsets of hMPM. This observation suggests that these kinases might represent novel therapeutic targets in this chemotherapy-resistant disease. Over these foundations, several promising studies are ongoing at preclinical level and novel molecules are currently under evaluation as well. Yet, established tumour cell lines, used for decades to investigate the efficacy of anticancer agents, although still the main source of drug efficacy studies, after long-term cultures tend to biologically diverge from the original tumour, limiting the predictive potential of in vivo efficacy. Cancer stem cells (CSCs), a subpopulation of malignant cells capable of self-renewal and multilineage differentiation, are believed to play an essential role in cancer initiation, growth, metastasization and relapse, being responsible of chemo- and radiotherapy refractoriness. According to the current carcinogenesis theory, CSCs represent the tumour-initiating cell (TIC) fraction, the only clonogenic subpopulation able to originate a tumour mass. Consequently, the recently described isolation of TICs from hMPM, the proposed main pharmacological target for novel antitumoural drugs, may contribute to better dissect the biology and multidrug resistance pathways controlling hMPM growth. PMID:22289125

  6. Ridge preservation using a new 3D collagen matrix: a preclinical study.

    PubMed

    Roman, Alexandra; Cioban, Cosmin; Stratul, Stefan-Ioan; Schwarz, Frank; Muste, Aurel; Petrutiu, Stefan-Adrian; Zaganescu, Raluca; Mihatovic, Ilja

    2015-07-01

    The success of ridge preservation techniques in reducing bone resorption is well documented, but no clear guidelines have been provided regarding the type of the biomaterial or technique to be used. This experimental animal study aimed at comparing the effectiveness of two ridge preservation techniques. Following the extraction of the distal roots of the mandibular second and fourth premolars of four dogs, the sockets were preserved using a combination of a collagen membrane intimately covering the socket plus a collagen matrix or a collagen membrane alone. The mandibular quadrants were randomly assigned to one of the treatment groups. Histomorphometrical analyses as well as microscopic observations were performed. After 5 months of healing, the histological analysis revealed a similar picture of bone formation in both groups. No significant differences between the buccal and lingual dimensions were calculated between the two treatment groups. The mucosa covering the alveolar ridges is significantly more abundant in post-extraction sockets preserved with the double-layered approach. The double-layered approach used to treat post-extraction sockets may result in a better preservation of the mucosal seal than the single-layered approach. The use of the new collagen matrix associated with a collagen membrane could be a clinical option to preserve post-extraction ridges, especially when an improvement in soft tissue dimension and quality is desired. However, the cost-benefit ratio of this approach should be thoroughly evaluated in further studies.

  7. Executive Function Changes before Memory in Preclinical Alzheimer’s Pathology: A Prospective, Cross-Sectional, Case Control Study

    PubMed Central

    Harrington, Michael G.; Chiang, Jiarong; Pogoda, Janice M.; Gomez, Megan; Thomas, Kris; Marion, Sarah DeBoard; Miller, Karen J.; Siddarth, Prabha; Yi, Xinyao; Zhou, Feimeng; Lee, Sherri; Arakaki, Xianghong; Cowan, Robert P.; Tran, Thao; Charleswell, Cherise; Ross, Brian D.; Fonteh, Alfred N.

    2013-01-01

    Background Early treatment of Alzheimer’s disease may reduce its devastating effects. By focusing research on asymptomatic individuals with Alzheimer’s disease pathology (the preclinical stage), earlier indicators of disease may be discovered. Decreasing cerebrospinal fluid beta-amyloid42 is the first indicator of preclinical disorder, but it is not known which pathology causes the first clinical effects. Our hypothesis is that neuropsychological changes within the normal range will help to predict preclinical disease and locate early pathology. Methods and Findings We recruited adults with probable Alzheimer’s disease or asymptomatic cognitively healthy adults, classified after medical and neuropsychological examination. By logistic regression, we derived a cutoff for the cerebrospinal fluid beta amyloid42/tau ratios that correctly classified 85% of those with Alzheimer’s disease. We separated the asymptomatic group into those with (n = 34; preclinical Alzheimer’s disease) and without (n = 36; controls) abnormal beta amyloid42/tau ratios; these subgroups had similar distributions of age, gender, education, medications, apolipoprotein-ε genotype, vascular risk factors, and magnetic resonance imaging features of small vessel disease. Multivariable analysis of neuropsychological data revealed that only Stroop Interference (response inhibition) independently predicted preclinical pathology (OR = 0.13, 95% CI = 0.04–0.42). Lack of longitudinal and post-mortem data, older age, and small population size are limitations of this study. Conclusions Our data suggest that clinical effects from early amyloid pathophysiology precede those from hippocampal intraneuronal neurofibrillary pathology. Altered cerebrospinal fluid beta amyloid42 with decreased executive performance before memory impairment matches the deposits of extracellular amyloid that appear in the basal isocortex first, and only later involve the hippocampus. We propose that Stroop

  8. Preclinical studies of VS‐505: a non‐absorbable highly effective phosphate binder

    PubMed Central

    Chen, Yung‐wu; Wong, Jonathan T; Wessale, Jerry L

    2016-01-01

    Abstract Background and Purpose Phosphate imbalance is often present in chronic kidney disease (CKD), and it contributes to a higher cardiovascular mortality rate. A phosphate binder is typically part of a treatment strategy for controlling phosphate imbalance. However, safety concerns and low compliance are two well‐recognized disadvantages of on‐market phosphate binders. This report describes the preclinical studies of VS‐505, a non‐absorbable, calcium‐ and aluminum‐free, plant‐derived polymer currently being evaluated in haemodialysis patients in Australia. Experimental Approach Normal Sprague Dawley (SD) rats or uraemic SD rats induced by 5/6 nephrectomy fed a high‐phosphate diet were treated with VS‐505 or sevelamer (0.05–10% in food) for 5 and 28 days respectively. Key Results Urinary and serum phosphate levels were significantly elevated in untreated rats, and were decreased by VS‐505 and sevelamer. VS‐505 increased faecal phosphate levels in a dose‐dependent manner. High‐phosphate diet also caused an increase in serum FGF‐23 and parathyroid hormone in nephrectomized (NX) rats, effects prevented by VS‐505 or sevelamer. Significant aortic calcification was observed in NX rats treated with 5% sevelamer, whereas VS‐505 at all doses tested did not show effects. VS‐505 had no effects on small intestine histomorphology and intestinal sodium‐dependent phosphate cotransporter gene expression. In vitro characterizations showed that VS‐505 has a relatively high density and low expansion volume when exposed to simulated gastric fluid. Conclusions and Implications VS‐505 is a safe and effective phosphate binder and may offer the advantage of having a reduced pill burden and minimal GI side effects for CKD patients. PMID:27156057

  9. Development, validation and application of a new fornix template for studies of aging and preclinical Alzheimer's disease.

    PubMed

    Brown, Christopher A; Johnson, Nathan F; Anderson-Mooney, Amelia J; Jicha, Gregory A; Shaw, Leslie M; Trojanowski, John Q; Van Eldik, Linda J; Schmitt, Frederick A; Smith, Charles D; Gold, Brian T

    2017-01-01

    We developed a merged younger-older adult template of the fornix and demonstrated its utility for studies of aging and preclinical Alzheimer's disease (AD). In Experiment 1, probabilistic tractography was used to reconstruct the fornix in younger and older adults and successful streamlines were then averaged to create a merged template in standard space. The new template includes the majority of the fornix from the hippocampal formation to the subcallosal region and the thalamus/hypothalamus. In Experiment 2, the merged template was validated as an appropriate measure for studies of aging, with comparisons against manual tracing measures indicating identical spatial coverage in younger and older adult groups. In Experiment 3, the merged template was found to outperform age-specific templates in measures of sensitivity and specificity computed on diffusion tensor imaging data of an independent participant cohort. In Experiment 4, relevance to preclinical AD was demonstrated via associations between fractional anisotropy within the new fornix template and cerebrospinal fluid markers of AD pathology (Aβ42 and the t-tau/Aβ42 ratio) in a third independent cohort of cognitively normal older adults. Our new template provides an appropriate measure for use in future studies seeking to characterize microstructural alterations in the fornix associated with aging and preclinical AD.

  10. Preclinical screening methods in cancer

    PubMed Central

    Kumar, Sachin; Bajaj, Sakshi; Bodla, Ramesh Babu

    2016-01-01

    Cancer, a group of diseases of unregulated cell proliferation, is a leading cause of death worldwide. More than 80% of compounds which have shown promising effects in preclinical studies could not get through Phase II of clinical trials. Such high attrition rate is due to improper or selective use of preclinical modalities in anticancer drug screening. The various preclinical screening methods available such as in vitro human cancer cell lines, in vivo tumor xenograft model, or genetically engineered mouse model have their respective pros and cons. Scrupulous use of these preclinical screening methods vis-à-vis efficacy of potential anticancer compound with diverse mechanism of action can help in bringing down the rate of failure of anticancer compound at clinical phase. This article provides an insight into the various preclinical methods used in anticancer studies along with their advantages and disadvantages. PMID:27721530

  11. Preclinical safety, pharmacokinetics, pharmacodynamics, and biodistribution studies with Ad35K++ protein: a novel rituximab cotherapeutic

    PubMed Central

    Richter, Maximilian; Yumul, Roma; Saydaminova, Kamola; Wang, Hongjie; Gough, Michael; Baldessari, Audrey; Cattaneo, Roberto; Lee, Frank; Wang, Chung-Huei Katherine; Jang, Haishan; Astier, Anne; Gopal, Ajay; Carter, Darrick; Lieber, André

    2016-01-01

    Rituximab is a mouse/human chimeric monoclonal antibody targeted toward CD20. It is efficient as first-line therapy of CD20-positive B-cell malignancies. However, a large fraction of treated patients relapse with rituximab-resistant disease. So far, only modest progress has been made in treatment options for rituximab refractory patients. One of the mechanisms for rituximab resistance involves the upregulation of CD46, which is a key cell surface protein that blocks the activation of complement. We have recently developed a technology that depletes CD46 from the cell surface and thereby sensitizes tumor cells to complement-dependent cytotoxicity. This technology is based on a small recombinant protein, Ad35K++ that binds with high affinity to CD46. In preliminary studies using a 6 × histidinyl tagged protein, we had demonstrated that intravenous Ad35K++ injection in combination with rituximab was safe and increased rituximab-mediated killing of CD20-positive target cells in mice and nonhuman primates (NHPs). The presence of the tag, while allowing for easy purification by Ni-NTA chromatography, has the potential to increase the immunogenicity of the recombinant protein. For clinical application, we therefore developed an Ad35K++ protein without His-tag. In the present study, we performed preclinical studies in two animal species (mice and NHPs) with this protein demonstrating its safety and efficacy. These studies estimated the Ad35K++ dose range and treatment regimen to be used in patients. Furthermore, we showed that intravenous Ad35K++ injection triggers the shedding of the CD46 extracellular domain in xenograft mouse tumor models and in macaques. Shed serum CD46 can be measured in the serum and can potentially be used as a pharmacodynamic marker for monitoring Ad35K++ activity in patient undergoing treatment with this agent. These studies create the basis for an investigational new drug application for the use of Ad35K++ in combination with rituximab in the

  12. A highly potent and selective farnesyltransferase inhibitor ABT-100 in preclinical studies.

    PubMed

    Gu, Wen-Zhen; Joseph, Ingrid; Wang, Yi-Chun; Frost, David; Sullivan, Gerard M; Wang, Le; Lin, Nan-Horng; Cohen, Jerry; Stoll, Vincent S; Jakob, Clarissa G; Muchmore, Steven W; Harlan, John E; Holzman, Tom; Walten, Karl A; Ladror, Uri S; Anderson, Mark G; Kroeger, Paul; Rodriguez, Luis E; Jarvis, Kenneth P; Ferguson, Debra; Marsh, Kennan; Ng, Shichung; Rosenberg, Saul H; Sham, Hing L; Zhang, Haiying

    2005-11-01

    Ras mutation has been detected in approximately 20-30% of all human carcinomas, primarily in pancreatic, colorectal, lung and bladder carcinomas. The indirect inhibition of Ras activity by inhibiting farnesyltransferase (FTase) function is one therapeutic intervention to control tumor growth. Here we report the preclinical anti-tumor activity of our most advanced FTase inhibitor (FTI), ABT-100, and a direct comparison with the current clinical candidates. ABT-100 is a highly selective, potent and orally bioavailable FTI. It broadly inhibits the growth of solid tumors in preclinical animal models. Thus, ABT-100 is an attractive candidate for further clinical evaluation. In addition, our results provide plausible insights to explain the impressive potency and selectivity of ABT-100. Finally, we have demonstrated that ABT-100 significantly suppresses the expression of vascular endothelial growth factor (VEGF) mRNA and secretion of VEGF protein, as well as inhibiting angiogenesis in the animal model.

  13. Nubac Disc Arthroplasty: Preclinical Studies and Preliminary Safety and Efficacy Evaluations

    PubMed Central

    Songer, Matthew; Pimenta, Luis; Werner, Dieter; Reyes-Sanchez, Alejandro; Balsano, Massimo; Agrillo, Umberto; Coric, Domagoj; Davenport, Kenneth; Yuan, Hansen

    2007-01-01

    fatigue properties for the intended application. The animal study showed that the Nubac caused no adverse local or systematic tissue reaction and there was no detectable wear debris. The preliminary clinical data showed no major intraoperative vascular and neurological complications. There was significant Visual Analog Scale and Oswestry Disability Index score improvement. Conclusions The preclinical data supported the design rationale, and the preliminary clinical data (level II evidence) on safety and efficacy were encouraging. Clinical Relevance The Nubac could be a viable first surgical option for patients with back pain caused by DDD. PMID:25802577

  14. Radiochemical studies, pre-clinical investigation and preliminary clinical evaluation of (170)Tm-EDTMP prepared using in-house freeze-dried EDTMP kit.

    PubMed

    Das, Tapas; Shinto, Ajit; Kamaleshwaran, Koramadai K; Sarma, Haladhar D; Mohammed, Sahiralam Khan; Mitra, Arpit; Lad, Sangita; Rajan, M G R; Banerjee, Sharmila

    2017-01-05

    The objective of the present work is to formulate (170)Tm-EDTMP using an in-house freeze-dried EDTMP kit and evaluate its potential as a bone pain palliation agent. Patient dose of (170)Tm-EDTMP was prepared with high radiochemical purity using the lyophilized kit at room temperature within 15min. Pre-clinical evaluation in normal Wistar rats revealed selective skeletal accumulation with extended retention. Preliminary clinical investigation in 8 patients with disseminated skeletal metastases exhibited selective uptake in the bone and retention therein for a long duration.

  15. In question: the scientific value of preclinical safety pharmacology and toxicology studies with cell-based therapies.

    PubMed

    Broichhausen, Christiane; Riquelme, Paloma; Ahrens, Norbert; Wege, Anja K; Koehl, Gudrun E; Schlitt, Hans J; Banas, Bernhard; Fändrich, Fred; Geissler, Edward K; Hutchinson, James A

    2014-01-01

    A new cell-based medicinal product containing human regulatory macrophages, known as Mreg_UKR, has been developed and conforms to expectations of a therapeutic drug. Here, Mreg_UKR was subjected to pharmacokinetic, safety pharmacology, and toxicological testing, which identified no adverse reactions. These results would normally be interpreted as evidence of the probable clinical safety of Mreg_UKR; however, we contend that, owing to their uncertain biological relevance, our data do not fully support this conclusion. This leads us to question whether there is adequate scientific justification for preclinical safety testing of similar novel cell-based medicinal products using animal models. In earlier work, two patients were treated with regulatory macrophages prior to kidney transplantation. In our opinion, the absence of acute or chronic adverse effects in these cases is the most convincing available evidence of the likely safety of Mreg_UKR in future recipients. On this basis, we consider that safety information from previous clinical investigations of related cell products should carry greater weight than preclinical data when evaluating the safety profile of novel cell-based medicinal products. By extension, we argue that omitting extensive preclinical safety studies before conducting small-scale exploratory clinical investigations of novel cell-based medicinal products data may be justifiable in some instances.

  16. Study of a new bone-targeting titanium implant–bone interface

    PubMed Central

    Liu, Xiangning; Zhang, Ye; Li, Shaobing; Wang, Yayu; Sun, Ting; Li, Zejian; Cai, Lizhao; Wang, Xiaogang; Zhou, Lei; Lai, Renfa

    2016-01-01

    New strategies involving bone-targeting titanium (Ti) implant–bone interface are required to enhance bone regeneration and osseointegration for orthopedic and dental implants, especially in osteoporotic subjects. In this study, a new dual-controlled, local, bone-targeting delivery system was successfully constructed by loading tetracycline-grafted simvastatin (SV)-loaded polymeric micelles in titania nanotube (TNT) arrays, and a bone-targeting Ti implant–bone interface was also successfully constructed by implanting the delivery system in vivo. The biological effects were evaluated both in vitro and in vivo. The results showed that Ti surfaces with TNT–bone-targeting micelles could promote cytoskeletal spreading, early adhesion, alkaline phosphatase activity, and extracellular osteocalcin concentrations of rat osteoblasts, with concomitant enhanced protein expression of bone morphogenetic protein (BMP)-2. A single-wall bone-defect implant model was established in normal and ovariectomized rats as postmenopausal osteoporosis models. Microcomputed tomography imaging and BMP-2 expression in vivo demonstrated that the implant with a TNT-targeting micelle surface was able to promote bone regeneration and osseointegration in both animal models. Therefore, beneficial biological effects were demonstrated both in vitro and in vivo, which indicated that the bone-targeting effects of micelles greatly enhance the bioavailability of SV on the implant–bone interface, and the provision of SV-loaded targeting micelles alone exhibits the potential for extensive application in improving local bone regeneration and osseointegration, especially in osteoporotic subjects. PMID:27932879

  17. Study of a new bone-targeting titanium implant-bone interface.

    PubMed

    Liu, Xiangning; Zhang, Ye; Li, Shaobing; Wang, Yayu; Sun, Ting; Li, Zejian; Cai, Lizhao; Wang, Xiaogang; Zhou, Lei; Lai, Renfa

    New strategies involving bone-targeting titanium (Ti) implant-bone interface are required to enhance bone regeneration and osseointegration for orthopedic and dental implants, especially in osteoporotic subjects. In this study, a new dual-controlled, local, bone-targeting delivery system was successfully constructed by loading tetracycline-grafted simvastatin (SV)-loaded polymeric micelles in titania nanotube (TNT) arrays, and a bone-targeting Ti implant-bone interface was also successfully constructed by implanting the delivery system in vivo. The biological effects were evaluated both in vitro and in vivo. The results showed that Ti surfaces with TNT-bone-targeting micelles could promote cytoskeletal spreading, early adhesion, alkaline phosphatase activity, and extracellular osteocalcin concentrations of rat osteoblasts, with concomitant enhanced protein expression of bone morphogenetic protein (BMP)-2. A single-wall bone-defect implant model was established in normal and ovariectomized rats as postmenopausal osteoporosis models. Microcomputed tomography imaging and BMP-2 expression in vivo demonstrated that the implant with a TNT-targeting micelle surface was able to promote bone regeneration and osseointegration in both animal models. Therefore, beneficial biological effects were demonstrated both in vitro and in vivo, which indicated that the bone-targeting effects of micelles greatly enhance the bioavailability of SV on the implant-bone interface, and the provision of SV-loaded targeting micelles alone exhibits the potential for extensive application in improving local bone regeneration and osseointegration, especially in osteoporotic subjects.

  18. Muscle Power Predicts Adolescent Bone Strength: Iowa Bone Development Study.

    PubMed

    Janz, Kathleen F; Letuchy, Elena M; Burns, Trudy L; Francis, Shelby L; Levy, Steven M

    2015-10-01

    To assess association between lower body muscle power and bone strength as well as the mediating effect of muscle cross-sectional area (MCSA) on that association. Participants (141 males and 162 females) were approximately 17 yr. Muscle power was predicted using vertical jump and the Sayers equation. Using peripheral quantitative computed tomography (pQCT), bone strength indices were obtained at two locations of the tibia, corresponding to primary stressors acting upon each site: bone strength index for compression (BSI) at the distal 4% site; density-weighted polar section modulus strength-strain index (SSIp) and cortical bone area (CoA) at the 66% midshaft site for torsion. Muscle cross-sectional area was measured at the 66% site. Pearson bivariate and partial correlation coefficients were estimated to quantify the strength of the associations among variables. Direct and indirect mediation model effects were estimated, and 95% bootstrap confidence intervals were constructed to test the causal hypothesis. Height and maturity were examined as covariates. Pearson correlation coefficients among muscle power, MCSA, and bone strength were statistically significant (P < 0.01) and ranged from r = 0.54 to r = 0.78. After adjustment for covariates, associations were reduced (r = 0.37 to 0.69) (P < 0.01). Mediation models for males for BSI, SSIp, and CoA accounted for 38%, 66%, and 54% of the variance in bone strength, respectively. Models for females for BSI, SSIp, and CoA accounted for 46%, 77%, and 66% of the variance, respectively. We found strong and consistent associations as well as direct and indirect pathways, among muscle power, MCSA, and tibia strength. These results support the use of muscle power as a component of health-related fitness in bone health interventions for older adolescents.

  19. Muscle Power Predicts Adolescent Bone Strength: Iowa Bone Development Study

    PubMed Central

    Janz, Kathleen F.; Letuchy, Elena M.; Burns, Trudy L.; Francis, Shelby L.; Levy, Steven M.

    2015-01-01

    Purpose To assess association between lower body muscle power and bone strength, as well as the mediating effect of muscle cross-sectional area (MCSA) on that association. Methods Participants (N=141 males; 162 females) were approximately 17 years. Muscle power was predicted using vertical jump and the Sayers equation. Using peripheral quantitative computed tomography (pQCT), bone strength indices were obtained at two locations of the tibia, corresponding to primary stressors acting upon each site: bone strength index for compression (BSI) at the distal 4% site; density-weighted polar section modulus strength-strain index [SSIp] and cortical bone area (CoA) at the 66% mid-shaft site for torsion. Muscle cross-sectional area (MCSA) was measured at the 66% site. Pearson bivariate and partial correlation coefficients were estimated to quantify the strength of the associations among variables. Direct and indirect mediation model effects were estimated and 95% bootstrap confidence intervals were constructed to test the causal hypothesis. Height and maturity were examined as covariates. Results Pearson correlation coefficients among muscle power, MCSA, and bone strength were statistically significant (p<0.01) and ranged from r=0.54 to 0.78. After adjustment for covariates, associations were reduced (r=0.37 to 0.69) (p<0.01). Mediation models for males for BSI, SSIp, and CoA accounted for 38%, 66%, and 54% of the variance in bone strength, respectively. Models for females for BSI, SSIp, and CoA accounted for 46%, 77%, and 66% of the variance, respectively. Conclusions We found strong and consistent associations, as well as direct and indirect pathways, among muscle power, MCSA, and tibia strength. These results support the use of muscle power as a component of health-related fitness in bone health interventions for older adolescents. PMID:25751769

  20. Evaluation of focused multipolar stimulation for cochlear implants: a preclinical safety study

    NASA Astrophysics Data System (ADS)

    Shepherd, Robert K.; Wise, Andrew K.; Enke, Ya Lang; Carter, Paul M.; Fallon, James B.

    2017-08-01

    Objective. Cochlear implants (CIs) have a limited number of independent stimulation channels due to the highly conductive nature of the fluid-filled cochlea. Attempts to develop highly focused stimulation to improve speech perception in CI users includes the use of simultaneous stimulation via multiple current sources. Focused multipolar (FMP) stimulation is an example of this approach and has been shown to reduce interaction between stimulating channels. However, compared with conventional biphasic current pulses generated from a single current source, FMP is a complex stimulus that includes extended periods of stimulation before charge recovery is achieved, raising questions on whether chronic stimulation with this strategy is safe. The present study evaluated the long-term safety of intracochlear stimulation using FMP in a preclinical animal model of profound deafness. Approach. Six cats were bilaterally implanted with scala tympani electrode arrays two months after deafening, and received continuous unilateral FMP stimulation at levels that evoked a behavioural response for periods of up to 182 d. Electrode impedance, electrically-evoked compound action potentials (ECAPs) and auditory brainstem responses (EABRs) were monitored periodically over the course of the stimulation program from both the stimulated and contralateral control cochleae. On completion of the stimulation program cochleae were examined histologically and the electrode arrays were evaluated for evidence of platinum (Pt) corrosion. Main results. There was no significant difference in electrode impedance between control and chronically stimulated electrodes following long-term FMP stimulation. Moreover, there was no significant difference between ECAP and EABR thresholds evoked from control or stimulated cochleae at either the onset of stimulation or at completion of the stimulation program. Chronic FMP stimulation had no effect on spiral ganglion neuron (SGN) survival when compared with

  1. Cell-Seeded Tubularized Scaffolds for Reconstruction of Long Urethral Defects: A Preclinical Study

    PubMed Central

    Orabi, Hazem; AbouShwareb, Tamer; Zhang, Yuanyuan; Yoo, James J.; Atala, Anthony

    2012-01-01

    Background The treatment options for patients requiring repair of a long segment of the urethra are limited by the availability of autologous tissues. We previously reported that acellular collagen-based tubularized constructs seeded with cells are able to repair small urethral defects in a rabbit model. Objective We explored the feasibility of engineering clinically relevant long urethras for surgical reconstruction in a canine preclinical model. Design, setting, and participants Autologous bladder epithelial and smooth muscle cells from 15 male dogs were grown and seeded onto preconfigured collagen-based tubular matrices (6 cm in length). The perineal urethral segment was removed in 21 male dogs. Urethroplasties were performed with tubularized collagen scaffolds seeded with cells in 15 animals. Tubularized constructs without cells were implanted in six animals. Serial urethrography and three-dimensional computed tomography (CT) scans were performed pre- and postoperatively at 1, 3, 6, and 12 mo. The animals were euthanized at their predetermined time points (three animals at 1 mo, and four at 3, 6, and 12 mo) for analyses. Outcome measurements and statistical analysis Statistical analysis of CT imaging and histology was not needed. Results and limitations CT urethrograms showed wide-caliber urethras without strictures in animals implanted with cell-seeded matrices. The urethral segments replaced with acellular scaffolds collapsed. Gross examination of the urethral implants seeded with cells showed normal-appearing tissue without evidence of fibrosis. Histologically, an epithelial cell layer surrounded by muscle fiber bundles was observed on the cell-seeded constructs, and cellular organization increased over time. The epithelial and smooth muscle phenotypes were confirmed using antibodies to pancytokeratins AE1/AE3 and smooth muscle–specific desmin. Formation of an epithelial cell layer occurred in the unseeded constructs, but few muscle fibers formed

  2. Dementia, Preclinical Studies in Neurodegeneration and its Potential for Translational Medicine in South America

    PubMed Central

    Cardona-Gómez, Gloria Patricia; Lopera, Francisco

    2016-01-01

    Latin-American people with dementia will increase to an astounding 368% in 2050, higher than USA and Europe. In addition, to sporadic dementia type like Alzheimer, and vascular dementia (VaD) progression after Cerebrovascular disease is also found. These incidences are increased in Colombia by specific populations affected with pure Neurodegenerative and VaDs like Autosomical Dominant familial Alzheimer’s disease (AD) and Cerebral Autosomal-Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL). In spite of the enormous human effort with and economical effort and investment costs, neither sporadic nor genetic kinds of dementia progression have been prevented or blocked yet. Currently, there exist several animal models that partially solve the understanding of the neurodegenerative etiopathogenesis and its treatment. However, when the potential therapies are translated to humans, those do not work or present a limited action. Main difficulties are the diverse comorbility associated to the cause and/or several affected brain regions, reducing the efficacy of some therapies which are limited to a tissue-specific action or modulating a kind of neurotransmission. Global investigation suggests that a general prevention could be achieved with the improvement in the quality of lifestyle, including healthy diet, physical and mental activity, and avoiding mechanical or chemical pro-inflammatory events in an early stage in the most of non-communicable diseases. In this review article, we present some molecular targets and preclinical studies in animal models to propose strategies that could be useful in a future translation to prevent or block neurodegeneration: one is gene therapy; silencing pathogenic genes in critical brain areas where excitotoxicity arise and spread. Another is to take advantage of the natural source and its wide biodiversity of natural products that are capable of identifying, by the blocking and prevention of

  3. Crestal bone resorption in augmented bone using mineralized freeze-dried bone allograft or pristine bone during submerged implant healing: a prospective study in humans.

    PubMed

    Huang, Hsiang-yun; Ogata, Yumi; Hanley, James; Finkelman, Matthew; Hur, Yong

    2016-02-01

    There is limited evidence on the crestal bone level changes around implants placed in bone augmented by guided bone regeneration (GBR) during submerged healing. The purpose of this study was to prospectively compare radiographic crestal bone changes around implants placed in augmented bone with changes around implants placed in pristine bone. Patients receiving dental implants in the augmented or pristine mandibular posterior edentulous ridge were included in the study. The digital standardized radiographs from the implant placement procedure were compared to the radiographs from the second-stage procedure to evaluate the peri-implant marginal bone level changes. The soft tissue thickness (ST), width of keratinized mucosa (wKM), and early cover screw exposure (eIE) were measured at the time of the second-stage procedure. A total of 29 implants in 26 patients, 11 in augmented bone (test group) and 18 in pristine bone (control group), were analyzed. The mean peri-implant bone loss (ΔBL) was 0.74 ± 0.74 mm (mean ± SD) in the test group and 0.25 ± 0.55 mm (mean ± SD) in the control group. The differences between the test and control groups in the mesial, distal, and mean peri-implant crestal bone level changes were statistically significant (P = 0.009, P = 0.004, and P = 0.001, respectively). The confounding factors (ST, wKM, and eIE) were adjusted. More peri-implant crestal bone loss during the submerged healing period was observed in augmented bone than in pristine bone. Augmented bone may not exhibit the same characteristics as pristine bone during the implant submerged healing period. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Searching For the Optimal Fluid to Restore Microcirculatory Flow Dynamics After Haemorrhagic Shock: A Systematic Review of Preclinical Studies.

    PubMed

    Naumann, David N; Beaven, Alastair; Dretzke, Janine; Hutchings, Sam; Midwinter, Mark J

    2016-12-01

    Increased microcirculatory flow and perfusion has been reported to improve clinical outcomes following shock. The optimal resuscitation fluid to restore the flow dynamics of the microcirculation is unknown. This review summarizes the preclinical literature to inform the direction and most important hypotheses for future clinical interventional studies. Standard systematic review methodology was utilized, and registered with the Collaborative Approach to Meta Analysis and Review of Animal Data from Experimental Studies (CAMARADES). Medline and Embase (via OVID SP) and SCOPUS were searched for all preclinical studies of haemorrhagic shock that compared fluid resuscitation of any kind (e.g., blood products, crystalloids, colloids, or haemoglobin based oxygen carriers) to another fluid or haemorrhage only, and reported at least one microcirculatory physical endpoint (such as flow rate, velocity, vessel diameter, functional capillary density, or glycocalyx thickness). Risk of bias was assessed using the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) tool. Translatability was also assessed for each study based on the most common recommendations. There were 3,103 potential studies of interest, of which 71 studies fulfilled all eligibility criteria. There were 62 rodent, 5 canine, and 4 porcine studies. Flow rate, velocity, and vessel diameter were the most commonly reported endpoints. Studies reported the importance of the presence of haemoglobin, as well as osmotic potential and viscosity in providing optimal restoration of microcirculatory flow dynamics. Others reported the restoration of the endothelial glycocalyx and attenuation of inflammation as important properties for the choice of fluid. All studies were at potential risk of bias due to unclear randomization, concealment, and blinding. There were important threats to translatability for all studies. The ideal resuscitation fluid for restoration of the microcirculation following

  5. In vivo and in vitro investigations of a nanostructured coating material – a preclinical study

    PubMed Central

    Adam, Martin; Ganz, Cornelia; Xu, Weiguo; Sarajian, Hamid-Reza; Götz, Werner; Gerber, Thomas

    2014-01-01

    Immediate loading of dental implants is only possible if a firm bone-implant anchorage at early stages is developed. This implies early and high bone apposition onto the implant surface. A nanostructured coating material based on an osseoinductive bone grafting is investigated in relation to the osseointegration at early stages. The goal is to transmit the structure (silica matrix with embedded hydroxyapatite) and the properties of the bone grafting into a coating material. The bone grafting substitute offers an osseoinductive potential caused by an exchange of the silica matrix in vivo accompanied by vascularization. X-ray diffraction and transmission electron microscopy analysis show that the coating material consists of a high porous silica matrix with embedded nanocrystalline hydroxyapatite with the same morphology as human hydroxyapatite. An in vitro investigation shows the early interaction between coating and human blood. Energy-dispersive X-ray analysis showed that the silica matrix was replaced by an organic matrix within a few minutes. Uncoated and coated titanium implants were inserted into the femora of New Zealand White rabbits. The bone-to-implant contact (BIC) was measured after 2, 4, and 6 weeks. The BIC of the coated implants was increased significantly at 2 and 4 weeks. After 6 weeks, the BIC was decreased to the level of the control group. A histological analysis revealed high bone apposition on the coated implant surface after 2 and 4 weeks. Osteoblastic and osteoclastic activities on the coating material indicated that the coating participates in the bone-remodeling process. The nanostructure of the coating material led to an exchange of the silica matrix by an autologous, organic matrix without delamination of the coating. This is the key issue in understanding initial bone formation on a coated surface. PMID:24627631

  6. Bone Forming Potential of An-Organic Bovine Bone Graft: A Cone Beam CT study.

    PubMed

    Uzbek, Usman Haider; Rahman, Shaifulizan Ab; Alam, Mohammad Khursheed; Gillani, Syed Wasif

    2014-12-01

    An-organic bovine bone graft is a xenograft with the potential of bone formation. The aim of this study was to evaluate the bone density using cone beam computed tomography scans around functional endosseous implant in the region of both augmented maxillary sinus with the an-organic bovine bone graft and the alveolar bone over which the graft was placed to provide space for the implants. Sterile freeze dried bovine bone graft produced by National Tissue Bank, University Sains, Malaysia was used for stage-1 implant placement with maxillary sinus augmentation in a total of 19 subjects with 19 implants. The age of all subjects ranged between 40-60 years with a mean age 51±4.70. All subjects underwent a follow up CT scan using PlanmecaPromax 3D(®) Cone beam computed tomography scanner at the Radiology department, Hospital University Sains, Malaysia. The collected data was then analysed to evaluate bone density in Hounsfield Units using PlanmecaRomexis" Imaging Software 2.2(®) which is specialized accompanying software of the cone beam computed tomography machine. There was bone formation seen at the site of the augmented sinus. A significant increase (p<0.005) in bone density was reported at the augmented site compared to the bone density of the existing alveolar bone. An-organic bovine bone graft is an osteoconductive material that can be used for the purpose of maxillary sinus augmentation.

  7. Bone Forming Potential of An-Organic Bovine Bone Graft: A Cone Beam CT study

    PubMed Central

    Rahman, Shaifulizan AB.; Alam, Mohammad Khursheed; Gillani, Syed Wasif

    2014-01-01

    Purpose: An-organic bovine bone graft is a xenograft with the potential of bone formation. The aim of this study was to evaluate the bone density using cone beam computed tomography scans around functional endosseous implant in the region of both augmented maxillary sinus with the an-organic bovine bone graft and the alveolar bone over which the graft was placed to provide space for the implants. Materials and Methods: Sterile freeze dried bovine bone graft produced by National Tissue Bank, University Sains, Malaysia was used for stage-1 implant placement with maxillary sinus augmentation in a total of 19 subjects with 19 implants. The age of all subjects ranged between 40-60 years with a mean age 51±4.70. All subjects underwent a follow up CT scan using PlanmecaPromax 3D® Cone beam computed tomography scanner at the Radiology department, Hospital University Sains, Malaysia. The collected data was then analysed to evaluate bone density in Hounsfield Units using PlanmecaRomexis” Imaging Software 2.2® which is specialized accompanying software of the cone beam computed tomography machine. Results: There was bone formation seen at the site of the augmented sinus. A significant increase (p<0.005) in bone density was reported at the augmented site compared to the bone density of the existing alveolar bone. Conclusion: An-organic bovine bone graft is an osteoconductive material that can be used for the purpose of maxillary sinus augmentation. PMID:25654037

  8. Percutaneous osteoplasty with a bone marrow nail for fractures of long bones: experimental study.

    PubMed

    Nakata, Kouhei; Kawai, Nobuyuki; Sato, Morio; Cao, Guang; Sahara, Shinya; Tanihata, Hirohiko; Takasaka, Isao; Minamiguchi, Hiroyuki; Nakai, Tomoki

    2010-09-01

    To develop percutaneous osteoplasty with the use of a bone marrow nail for fixation of long-bone fractures, and to evaluate its feasibility and safety in vivo and in vitro. Six long bones in three healthy swine were used in the in vivo study. Acrylic cement was injected through an 11-gauge bone biopsy needle and a catheter into a covered metallic stent placed within the long bone, creating a bone marrow nail. In the in vitro study, we determined the bending, tug, and compression strengths of the acrylic cement nails 9 cm long and 8 mm in diameter (N = 10). The bending strength of the artificially fractured bones (N = 6) restored with the bone marrow nail and cement augmentation was then compared with that of normal long bones (N = 6). Percutaneous osteoplasty with a bone marrow nail was successfully achieved within 1 hour for all swine. After osteoplasty, all swine regained the ability to run until they were euthanized. Blood tests and pathologic findings showed no adverse effects. The mean bending, tug, and compression strengths of the nail were 91.4 N/mm(2) (range, 75.0-114.1 N/mm(2)), 20.9 N/mm(2) (range, 6.6-30.4 N/mm(2)), and 103.0 N/mm(2) (range, 96.3-110.0 N/mm(2)), respectively. The bending strength ratio of artificially fractured bones restored with bone marrow nail and cement augmentation to normal long bone was 0.32. Percutaneous osteoplasty with use of a bone marrow nail and cement augmentation appears to have potential in treating fractures of non-weight-bearing long bones. Copyright 2010 SIR. Published by Elsevier Inc. All rights reserved.

  9. Assessment of cell sheets derived from human periodontal ligament cells: a pre-clinical study.

    PubMed

    Washio, Kaoru; Iwata, Takanori; Mizutani, Manabu; Ando, Tomohiro; Yamato, Masayuki; Okano, Teruo; Ishikawa, Isao

    2010-09-01

    Periodontal-ligament-derived cells (PDL cells) have stem-cell-like properties and, when implanted into periodontal defects in vivo, can induce periodontal regeneration including the formation of new bone, cementum, and periodontal ligament. We have previously demonstrated that PDL cell sheets, harvested from temperature-responsive cell culture dishes, have a great potential for periodontal regeneration. The purpose of this study has been to validate the safety and efficacy of human PDL (hPDL) cell sheets for use in clinical trials. hPDL tissues from three donors were enzymatically digested, and the obtained cells were cultured with media containing autologous serum in a cell-processing center (CPC). The safety and efficacy of hPDL cell sheets were evaluated both in vitro and in vivo. In vitro studies showed that the hPDL cell sheets had high alkaline phosphatase activity and periostin expression (known PDL markers) and no contamination with microorganisms. In vivo studies revealed that hPDL cell sheets, implanted with dentin blocks, induced the formation of cementum and PDL-like tissue in immunodeficient mice. The hPDL cells presented no evidence of malignant transformation. Thus, hPDL cell sheets created in CPCs are safe products and possess the potential to regenerate periodontal tissues.

  10. Attempted and Successful Compensation in Preclinical and Early Manifest Neurodegeneration – A Review of Task fMRI Studies

    PubMed Central

    Scheller, Elisa; Minkova, Lora; Leitner, Mathias; Klöppel, Stefan

    2014-01-01

    Several models of neural compensation in healthy aging have been suggested to explain brain activity that aids to sustain cognitive function. Applying recently suggested criteria of “attempted” and “successful” compensation, we reviewed existing literature on compensatory mechanisms in preclinical Huntington’s disease (HD) and amnestic mild cognitive impairment (aMCI). Both disorders constitute early stages of neurodegeneration ideal for examining compensatory mechanisms and developing targeted interventions. We strived to clarify whether compensation criteria derived from healthy aging populations can be applied to early neurodegeneration. To concentrate on the close coupling of cognitive performance and brain activity, we exclusively addressed task fMRI studies. First, we found evidence for parallels in compensatory mechanisms between healthy aging and neurodegenerative disease. Several studies fulfilled criteria of attempted compensation, while reports of successful compensation were largely absent, which made it difficult to conclude on. Second, comparing working memory studies in preclinical HD and aMCI, we identified similar compensatory patterns across neurodegenerative disorders in lateral and medial prefrontal cortex. Such patterns included an inverted U-shaped relationship of neurodegeneration and compensatory activity spanning from preclinical to manifest disease. Due to the lack of studies systematically targeting all criteria of compensation, we propose an exemplary study design, including the manipulation of compensating brain areas by brain stimulation. Furthermore, we delineate the benefits of targeted interventions by non-invasive brain stimulation, as well as of unspecific interventions such as physical activity or cognitive training. Unambiguously detecting compensation in early neurodegenerative disease will help tailor interventions aiming at sustained overall functioning and delayed clinical disease onset. PMID:25324786

  11. Bone Regeneration Using Bone Morphogenetic Proteins and Various Biomaterial Carriers

    PubMed Central

    Sheikh, Zeeshan; Javaid, Mohammad Ahmad; Hamdan, Nader; Hashmi, Raheel

    2015-01-01

    Trauma and disease frequently result in fractures or critical sized bone defects and their management at times necessitates bone grafting. The process of bone healing or regeneration involves intricate network of molecules including bone morphogenetic proteins (BMPs). BMPs belong to a larger superfamily of proteins and are very promising and intensively studied for in the enhancement of bone healing. More than 20 types of BMPs have been identified but only a subset of BMPs can induce de novo bone formation. Many research groups have shown that BMPs can induce differentiation of mesenchymal stem cells and stem cells into osteogenic cells which are capable of producing bone. This review introduces BMPs and discusses current advances in preclinical and clinical application of utilizing various biomaterial carriers for local delivery of BMPs to enhance bone regeneration. PMID:28788032

  12. Bovine bone matrix/poly(l-lactic-co-ε-caprolactone)/gelatin hybrid scaffold (SmartBone(®)) for maxillary sinus augmentation: A histologic study on bone regeneration.

    PubMed

    D'Alessandro, Delfo; Perale, Giuseppe; Milazzo, Mario; Moscato, Stefania; Stefanini, Cesare; Pertici, Gianni; Danti, Serena

    2016-10-18

    The ideal scaffold for bone regeneration is required to be highly porous, non-immunogenic, biostable until the new tissue formation, bioresorbable and osteoconductive. This study aimed at investigating the process of new bone formation in patients treated with granular SmartBone(®) for sinus augmentation, providing an extensive histologic analysis. Five biopsies were collected at 4-9 months post SmartBone(®) implantation and processed for histochemistry and immunohistochemistry. Histomorphometric analysis was performed. Bone-particle conductivity index (BPCi) was used to assess SmartBone(®) osteoconductivity. At 4 months, SmartBone(®) (12%) and new bone (43.9%) were both present and surrounded by vascularized connective tissue (37.2%). New bone was grown on SmartBone(®) (BPCi=0.22). At 6 months, SmartBone(®) was almost completely resorbed (0.5%) and new bone was massively present (80.8%). At 7 and 9 months, new bone accounted for a large volume fraction (79.3% and 67.4%, respectively) and SmartBone(®) was resorbed (0.5% and 0%, respectively). Well-oriented lamellae and bone scars, typical of mature bone, were observed. In all the biopsies, bone matrix biomolecules and active osteoblasts were visible. The absence of inflammatory cells confirmed SmartBone(®) biocompatibility and non-immunogenicity. These data indicate that SmartBone(®) is osteoconductive, promotes fast bone regeneration, leading to mature bone formation in about 7 months.

  13. Prevention of graft rejection in allogeneic bone marrow transplantation. II. Preclinical studies with three radiation protocols

    SciTech Connect

    Malilay, G.P.; Sevenich, E.A.; Filipovich, A.H. )

    1990-09-01

    Three radiotherapeutic regimens were compared in vitro to determine their immunosuppressive potential against non-MHC-restricted cytotoxic cells. Assays of natural killer and lymphokine-activated killer function, and cytotoxicity against allogeneic cells were used to quantitate the cytotoxic potential of peripheral blood mononuclear cells from healthy individuals following irradiation with a single dose of 1000 cGy on day 0, 1320 cGy of fractionated radiation (165 cGy b.i.d. x 4 days), or split-dose irradiation consisting of 1000 cGy on day 0 followed 5 or 7 days later by 500 cGy. Both irradiated and nonirradiated (control) PBMC cultures were maintained in culture with medium containing interleukin-2, immunophenotyped, and assayed for cytotoxicity from 1 to 8 days after irradiation. Single dose and fractionated-dose irradiation resulted in a progressive decline in cytotoxic capacity, with an 80% inhibition of both NK and LAK cell activity 8 days after onset of irradiation. The split dose of 500 cGy administered 7 days after a dose of 1000 cGy was found to be the most effective in eliminating NK (93% inhibition) and LAK (100% inhibition) cytotoxicity. These data indicate that split-dose irradiation may result in greater immunosuppression than single-dose or fractionated irradiation.

  14. X-Ray Exam: Bone Age Study (For Parents)

    MedlinePlus

    ... 2-Year-Old X-Ray Exam: Bone Age Study KidsHealth > For Parents > X-Ray Exam: Bone Age Study A A A What's in this article? What ... edad ósea What It Is A bone age study helps doctors estimate the maturity of a child's ...

  15. Effects of bone drilling on local temperature and bone regeneration: an in vivo study.

    PubMed

    Karaca, Faruk; Aksakal, Bünyamin; Köm, Mustafa

    2014-01-01

    The aim of this study was to examine the influence of bone drilling on local bone temperature and bone regeneration and determine optimal drilling speed and pressure in an animal model. The study included 12 skeletally mature New Zealand white rabbits, weighing between 2.8 to 3.2 kg. Rabbits were divided into 2 groups and euthanized at the end of Day 21 (Group A) and Day 42 (Group B). The same drilling protocol was used in both groups. Three drill holes with different pressure (5, 10 and 20 N) were made in each rabbit tibias using 3 different rotational drill speeds (230, 370 and 570 rpm). During drilling, local temperature was recorded. Rabbit tibia underwent histopathological exam for bone regeneration. Bone temperature was affected by drilling time and depth. Lower drill speeds reduced the bone temperature and revealed better bone regeneration when compared to the drilled bones at higher drill speeds. Titanium boron nitride coating on the drill bits had no significant effects on bone temperature and structure. Bone regeneration was superior in Group B rabbits that had drilling at 230 rpm and 20 N. Our results suggested that lower drilling speed with higher pressure is necessary for better bone regeneration. The optimal drilling speed is 230 rpm and optimal drilling pressure 20 N.

  16. Preclinical and Pilot Clinical Studies of Docetaxel Chemoradiation for Stage III Non-Small-Cell Lung Cancer

    SciTech Connect

    Chen Yuhchyau; Pandya, Kishan J.; Hyrien, Ollivier; Keng, Peter C.; Smudzin, Therese; Anderson, Joy; Qazi, Raman; Smith, Brian; Watson, Thomas J.; Feins, Richard H.; Johnstone, David W.

    2011-08-01

    Purpose: Local and distant failure rates remain high despite aggressive chemoradiation (CRT) treatment for Stage III non-small-cell lung cancer. We conducted preclinical studies of docetaxel's cytotoxic and radiosensitizing effects on lung cancer cell lines and designed a pilot study to target distant micrometastasis upfront with one-cycle induction chemotherapy, followed by low-dose radiosensitizing docetaxel CRT. Methods and Materials: A preclinical study was conducted in human lung cancer cell lines NCI 520 and A549. Cells were treated with two concentrations of docetaxel for 3 h and then irradiated immediately or after a 24-h delay. A clonogenic survival assay was conducted and analyzed for cytotoxic effects vs. radiosensitizing effects of docetaxel. A pilot clinical study was designed based on preclinical study findings. Twenty-two patients were enrolled with a median follow-up of 4 years. Induction chemotherapy consisted of 75 mg/m{sup 2} of docetaxel and 75 mg/m{sup 2} of cisplatin on Day 1 and 150 mg/m{sup 2} of recombinant human granulocyte colony-stimulating factor on Days 2 through 10. Concurrent CRT was started 3 to 6 weeks later with twice-weekly docetaxel at 10 to 12 mg/m{sup 2} and daily delayed radiation in 1.8-Gy fractions to 64.5 Gy for gross disease. Results: The preclinical study showed potent cytotoxic effects of docetaxel and subadditive radiosensitizing effects. Delaying radiation resulted in more cancer cell death. The pilot clinical study resulted in a median survival of 32.6 months for the entire cohort, with 3- and 5-year survival rates of 50% and 19%, respectively, and a distant metastasis-free survival rate of 61% for both 3 and 5 years. A pattern-of-failure analysis showed 75% chest failures and 36% all-distant failures. Therapy was well tolerated with Grade 3 esophagitis observed in 23% of patients. Conclusions: One-cycle full-dose docetaxel/cisplatin induction chemotherapy with recombinant human granulocyte colony-stimulating factor

  17. Impact of the Genetics and Source of Preclinical Safety Animal Models on Study Design, Results, and Interpretation.

    PubMed

    Colman, Karyn

    2017-01-01

    It has been long established that not only the species but also the strain and supplier of rodents used in preclinical safety studies can have a significant impact on the outcome of studies due to variability in their genetic background and thus spontaneous pathologic findings. In addition, local husbandry, housing, and other environmental conditions may have effects on the development and expression of comorbidities, particularly in longer-term or chronic studies. More recently, similar effects related to the source, including genetic and environmental variability, have been recognized in cynomolgus macaques ( Macaca fascicularis). The increased use of cynomolgus macaques from various sources of captive-bred animals (including nonnative, U.S./European Union-based breeding facilities or colonies) can affect study design and study results and outcome. It is important to acknowledge and understand the impact of this variability on the results and interpretation of research studies. This review includes recent examples where variability of preclinical animal models (rats and monkeys) affected the postmortem observations highlighting its relevance to study design or interpretation in safety studies.

  18. [Preclinical in vitro and in vivo models for the assessment of biological activity in biosimilarity studies].

    PubMed

    Escobedo-Moratilla, Abraham; Barba de la Rosa, Ana Paulina; Pérez-Urizar, José Trinidad

    2015-01-01

    A drug that contains a recombinant protein as an active principle is called a biotechnological drug or biopharmaceutical.There are currently over 300 biopharmaceuticals worldwide. Many of these contains a similar active principle (biosimilar drug) as other previously registered (innovator drug). It has suggested that due to the complex implications in a formulation containing a protein, the manufacturing process is a key factor for efficacy and safety requirements. In fact, certain variability has been detected of the protein properties in different lots (or batches) of the same manufacturer, which produce changes at a clinical level. For this reason, the evaluation of biosimilar drugs has acquired great relevance, being the preclinical level of one of the more important stages of the development due to its lower cost (with respect to the clinical level) and its high capacity to detect formulation-manufacture problems. However, the demonstration of comparability at physicochemical, preclinical, and clinical levels is required in order to achieve market registration. In this review the in vitro and in vivo models used for the assessment of proposed biosimilars will be discussed.

  19. Pre-Clinical Studies of Epigenetic Therapies Targeting Histone Modifiers in Lung Cancer

    PubMed Central

    Huffman, Kenneth; Martinez, Elisabeth D.

    2013-01-01

    Treatment options for lung cancer patients have been generally limited to standard therapies or targeted interventions which involve a small number of known mutations. Although the targeted therapies are initially successful, they most often result in drug resistance, relapse, and mortality. We now know that the complexity of lung cancer comes not only from genomic changes, but also from aberrant epigenetic regulatory events. Epigenetic therapies have shown promise as single agents in the treatment of hematological malignancies but have yet to meet this expectation in solid tumors thus fostering researchers to pursue new approaches in the development and use of epigenetic interventions. Here, we review some recent pre-clinical findings involving the use of drugs targeting histone modifying enzymes both as single agents and as co-therapies against lung cancer. A greater understanding of the impact of these epigenetic compounds in lung cancer signaling is needed and further evaluation in vivo is warranted in several cases based on the pre-clinical activity of a subset of compounds discussed in this review, including drugs co-targeting HDACs and EGF receptor, targeting Brd4 and targeting Jumonji histone demethylases. PMID:24058902

  20. Pre-Clinical Study of Panobinostat in Xenograft and Genetically Engineered Murine Diffuse Intrinsic Pontine Glioma Models

    PubMed Central

    Olaciregui, Nagore G.; Barton, Kelly L.; Ehteda, Anahid; Chitranjan, Arjanna; Chang, Cecilia; Gifford, Andrew J.; Tsoli, Maria; Ziegler, David S.; Carcaboso, Angel M.; Becher, Oren J.

    2017-01-01

    Background Diffuse intrinsic pontine glioma (DIPG), or high-grade brainstem glioma (BSG), is one of the major causes of brain tumor-related deaths in children. Its prognosis has remained poor despite numerous efforts to improve survival. Panobinostat, a histone deacetylase inhibitor, is a targeted agent that has recently shown pre-clinical efficacy and entered a phase I clinical trial for the treatment of children with recurrent or progressive DIPG. Methods A collaborative pre-clinical study was conducted using both a genetic BSG mouse model driven by PDGF-B signaling, p53 loss, and ectopic H3.3-K27M or H3.3-WT expression and an H3.3-K27M orthotopic DIPG xenograft model to confirm and extend previously published findings regarding the efficacy of panobinostat in vitro and in vivo. Results In vitro, panobinostat potently inhibited cell proliferation, viability, and clonogenicity and induced apoptosis of human and murine DIPG cells. In vivo analyses of tissue after short-term systemic administration of panobinostat to genetically engineered tumor-bearing mice indicated that the drug reached brainstem tumor tissue to a greater extent than normal brain tissue, reduced proliferation of tumor cells and increased levels of H3 acetylation, demonstrating target inhibition. Extended consecutive daily treatment of both genetic and orthotopic xenograft models with 10 or 20 mg/kg panobinostat consistently led to significant toxicity. Reduced, well-tolerated doses of panobinostat, however, did not prolong overall survival compared to vehicle-treated mice. Conclusion Our collaborative pre-clinical study confirms that panobinostat is an effective targeted agent against DIPG human and murine tumor cells in vitro and in short-term in vivo efficacy studies in mice but does not significantly impact survival of mice bearing H3.3-K27M-mutant tumors. We suggest this may be due to toxicity associated with systemic administration of panobinostat that necessitated dose de-escalation. PMID

  1. Surface studies on acrylic bone cement.

    PubMed

    Bettencourt, A; Calado, A; Amaral, J; Alfaia, A; Vale, F M; Monteiro, J; Montemor, M F; Ferreira, M G S; Castro, M

    2004-06-18

    Poly(methyl methacrylate) (PMMA) is used to fill the gap between the prosthesis and the surrounding bone in cemented arthroplasties. Biocompatibility problems related to bone cement application limit the clinical success of these cemented arthroplasties. Being the cement surface in close connection with the living bone, it is reasonable to assume that surface properties such as, surface composition and surface energy, will play a role in the biomaterial performance. X-ray photoelectron spectroscopy (XPS) analysis and surface energy studies were carried out during 4 months, in order to assess a possible correlation between aging time and surface changes. The aging of PMMA, in a biological model fluid, strongly influences the composition and wettability of the cement surface. These changes may be explained through the hydrolysis of PMMA ester groups and the subsequent hydrogen bonding. Although our study does not exactly reproduce the in vivo environment surrounding a prosthesis, it suggests that the changes in the composition and wettability of the surface may modulate the host response towards the implant, thus contributing to its loosening.

  2. Threats to Validity in the Design and Conduct of Preclinical Efficacy Studies: A Systematic Review of Guidelines for In Vivo Animal Experiments

    PubMed Central

    Henderson, Valerie C.; Kimmelman, Jonathan; Fergusson, Dean; Grimshaw, Jeremy M.; Hackam, Dan G.

    2013-01-01

    Background The vast majority of medical interventions introduced into clinical development prove unsafe or ineffective. One prominent explanation for the dismal success rate is flawed preclinical research. We conducted a systematic review of preclinical research guidelines and organized recommendations according to the type of validity threat (internal, construct, or external) or programmatic research activity they primarily address. Methods and Findings We searched MEDLINE, Google Scholar, Google, and the EQUATOR Network website for all preclinical guideline documents published up to April 9, 2013 that addressed the design and conduct of in vivo animal experiments aimed at supporting clinical translation. To be eligible, documents had to provide guidance on the design or execution of preclinical animal experiments and represent the aggregated consensus of four or more investigators. Data from included guidelines were independently extracted by two individuals for discrete recommendations on the design and implementation of preclinical efficacy studies. These recommendations were then organized according to the type of validity threat they addressed. A total of 2,029 citations were identified through our search strategy. From these, we identified 26 guidelines that met our eligibility criteria—most of which were directed at neurological or cerebrovascular drug development. Together, these guidelines offered 55 different recommendations. Some of the most common recommendations included performance of a power calculation to determine sample size, randomized treatment allocation, and characterization of disease phenotype in the animal model prior to experimentation. Conclusions By identifying the most recurrent recommendations among preclinical guidelines, we provide a starting point for developing preclinical guidelines in other disease domains. We also provide a basis for the study and evaluation of preclinical research practice. Please see later in the article

  3. Threats to validity in the design and conduct of preclinical efficacy studies: a systematic review of guidelines for in vivo animal experiments.

    PubMed

    Henderson, Valerie C; Kimmelman, Jonathan; Fergusson, Dean; Grimshaw, Jeremy M; Hackam, Dan G

    2013-01-01

    The vast majority of medical interventions introduced into clinical development prove unsafe or ineffective. One prominent explanation for the dismal success rate is flawed preclinical research. We conducted a systematic review of preclinical research guidelines and organized recommendations according to the type of validity threat (internal, construct, or external) or programmatic research activity they primarily address. We searched MEDLINE, Google Scholar, Google, and the EQUATOR Network website for all preclinical guideline documents published up to April 9, 2013 that addressed the design and conduct of in vivo animal experiments aimed at supporting clinical translation. To be eligible, documents had to provide guidance on the design or execution of preclinical animal experiments and represent the aggregated consensus of four or more investigators. Data from included guidelines were independently extracted by two individuals for discrete recommendations on the design and implementation of preclinical efficacy studies. These recommendations were then organized according to the type of validity threat they addressed. A total of 2,029 citations were identified through our search strategy. From these, we identified 26 guidelines that met our eligibility criteria--most of which were directed at neurological or cerebrovascular drug development. Together, these guidelines offered 55 different recommendations. Some of the most common recommendations included performance of a power calculation to determine sample size, randomized treatment allocation, and characterization of disease phenotype in the animal model prior to experimentation. By identifying the most recurrent recommendations among preclinical guidelines, we provide a starting point for developing preclinical guidelines in other disease domains. We also provide a basis for the study and evaluation of preclinical research practice. Please see later in the article for the Editors' Summary.

  4. Turmeric (Curcuma longa) rhizome paste and honey show similar wound healing potential: a preclinical study in rabbits.

    PubMed

    Kundu, Subarna; Biswas, Tuhin Kanti; Das, Partha; Kumar, Saurabh; De, Dipak Kumar

    2005-12-01

    The potential efficacy of fresh turmeric (Curcuma longa) paste to heal wounds was tested in a preclinical study in an animal model. Turmeric paste was compared with honey as a topical medicament against a control on experimentally created full-thickness circular wounds in 18 rabbits (Oryctolagous cuniculus). Wound healing was assessed on the basis of physical, histomorphological, and histochemical parameters on treatment days 0, 3, 7, and 14. Only tensile strength was measured on day 14 of treatment. It was observed that the wound healing was statistically significantly faster (P < .01) in both treatment groups compared to the control group.

  5. Preclinical acute toxicity, biodistribution, pharmacokinetics, radiation dosimetry and microPET imaging studies of [(18)F]fluorocholine in mice.

    PubMed

    Silveira, Marina B; Ferreira, Soraya M Z M D; Nascimento, Leonardo T C; Costa, Flávia M; Mendes, Bruno M; Ferreira, Andrea V; Malamut, Carlos; Silva, Juliana B; Mamede, Marcelo

    2016-10-01

    [(18)F]Fluorocholine ([(18)F]FCH) has been proven to be effective in prostate cancer. Since [(18)F]FCH is classified as a new radiopharmaceutical in Brazil, preclinical safety and efficacy data are required to support clinical trials and to obtain its approval. The aim of this work was to perform acute toxicity, biodistribution, pharmacokinetics, radiation dosimetry and microPET imaging studies of [(18)F]FCH. The results could support its use in nuclear medicine as an important piece of work for regulatory in Brazil.

  6. Composite vascularized skin/bone transplantation models for bone marrow-based tolerance studies.

    PubMed

    Ozmen, Selahattin; Ulusal, Betul G; Ulusal, Ali E; Izycki, Dariusz; Siemionow, Maria

    2006-03-01

    There is an ongoing need to understand the mechanisms of bone marrow-based allograft tolerance. This is important in clarifying the diverse variables influencing the ultimate outcome of the solid organ and composite tissue transplants. To establish bone marrow transplantation as a routine clinical application, further experimental studies should be conducted to overcome the obstacles related to the bone marrow transplantation. These obstacles include graft versus host disease, immunocompetence, and toxicity of the conditioning regimens. For these purposes, novel experimental models are needed. In an attempt to provide a reliable research tool for bone marrow-based tolerance induction studies, we introduced different experimental models of modified vascularized skin/bone marrow (VSBM) transplantation technique for tolerance induction, monitoring, and maintenance studies. In this skin/bone transplantation model, the technical feasibility of concurrent or consecutive transplantation of the combination of bilateral vascularized skin, vascularized bone marrow, or vascularized skin/bone marrow transplants was investigated. Isograft transplantations were performed between genetically identical Lewis (LEW, RT1) rats. Five different experimental designs in 5 groups of 5 animals each were studied. Group I: Bilateral vascularized skin (VS) transplantation; group II: bilateral vascularized skin/bone transplantation; group III: vascularized skin transplantation on one side and vascularized skin/bone transplantation on the contralateral side; group IV: vascularized bone transplantation on one side and vascularized skin/bone transplantation on the contralateral side; group V: vascularized bone transplantation on one side and vascularized skin transplantation on the contralateral side. Successful transplantations were performed in all groups. The survival of the isograft transplants was evaluated clinically and histologically. All skin flaps remained pink and pliable and grew new

  7. Blastomycosis of bone: a clinicopathologic study.

    PubMed

    Jain, Richa; Singh, Kamaljit; Lamzabi, Ihab; Harbhajanka, Aparna; Gattuso, Paolo; Reddy, Vijaya B

    2014-11-01

    Blastomycosis osteomyelitis is a well-known but infrequently encountered complication of infection with the dimorphic mold, Blastomyces dermatitidis. Oftentimes, the diagnosis is unsuspected, resulting in a delay in making the diagnosis. The role of intraoperative consultation in making a rapid diagnosis has not been discussed previously. Retrospective chart review of clinicopathologic information was conducted from all cases of blastomycosis osteomyelitis and arthritis diagnosed at Rush University Medical Center between 2000 and 2010. Fourteen cases of blastomycosis osteomyelitis and/or arthritis were identified, 12 of which clinically and radiologically presented as a bone tumor. The disease most commonly affected the lower extremities, particularly around the knee joint. Septic arthritis generally occurred secondary to osteomyelitis of the adjacent bone. Frozen section was performed in 10 cases, all of which were correctly diagnosed as granulomatous osteomyelitis. Two cases were culture negative, one of which showed many budding yeast forms typical of B dermatitidis on histology. Blastomycosis osteomyelitis should be considered in the differential diagnosis of bone tumor, particularly when there is history of residence or travel in endemic areas. This disease can be correctly identified at frozen section, thus offering rapid diagnosis. There is an excellent correlation between morphologic and microbiologic studies. Copyright© by the American Society for Clinical Pathology.

  8. Trajectories of memory decline in preclinical Alzheimer's disease: results from the Australian Imaging, Biomarkers and Lifestyle Flagship Study of ageing.

    PubMed

    Pietrzak, Robert H; Lim, Yen Ying; Ames, David; Harrington, Karra; Restrepo, Carolina; Martins, Ralph N; Rembach, Alan; Laws, Simon M; Masters, Colin L; Villemagne, Victor L; Rowe, Christopher C; Maruff, Paul

    2015-03-01

    Memory changes in preclinical Alzheimer's disease (AD) are often characterized by heterogenous trajectories. However, data regarding the nature and determinants of predominant trajectories of memory changes in preclinical AD are lacking. We analyzed data from 333 cognitively healthy older adults who participated in a multicenter prospective cohort study with baseline and 18-, 36-, and 54-month follow-up assessments. Latent growth mixture modeling revealed 3 predominant trajectories of memory change: a below average, subtly declining memory trajectory (30.9%); a below average, rapidly declining memory trajectory (3.6%); and an above average, stable memory trajectory (65.5%). Compared with the stable memory trajectory, high Αβ (relative risk ratio [RRR] = 2.1), and lower Mini-Mental State Examination (RRR = 0.6) and full-scale IQ (RRR = 0.9) scores were independently associated with the subtly declining memory trajectory; and high Αβ (RRR = 8.3), APOE ε4 carriage (RRR = 6.1), and greater subjective memory impairment (RRR = 1.2) were independently associated with the rapidly declining memory trajectory. Compared with the subtly declining memory trajectory group, APOE ε4 carriage (RRR = 8.4), and subjective memory complaints (RRR = 1.2) were associated with a rapidly declining memory trajectory. These results suggest that the preclinical phase of AD may be characterized by 2 predominant trajectories of memory decline that have common (e.g., high Αβ) and unique (e.g., APOE ε4 genotype) determinants. Published by Elsevier Inc.

  9. Comparative study between cortical bone graft versus bone dust for reconstruction of cranial burr holes.

    PubMed

    Worm, Paulo V; Ferreira, Nelson P; Faria, Mario B; Ferreira, Marcelo P; Kraemer, Jorge L; Collares, Marcus V M

    2010-12-22

    As a consequence of the progressive evolution of neurosurgical techniques, there has been increasing concern with the esthetic aspects of burr holes. Therefore, the objective of this study was to compare the use of cortical bone graft and bone dust for correcting cranial deformities caused by neurosurgical trephines. Twenty-three patients were enrolled for cranial burr hole reconstruction with a 1-year follow-up. A total of 108 burr holes were treated; 36 burr holes were reconstructed with autogenous cortical bone discs (33.3%), and the remaining 72 with autogenous wet bone powder (66.6%). A trephine was specifically designed to produce this coin-shaped bone plug of 14 mm in diameter, which fit perfectly over the burr holes. The reconstructions were studied 12 months after the surgical procedure, using three-dimensional quantitative computed tomography. Additionally, general and plastic surgeons blinded for the study evaluated the cosmetic results of those areas, attributing scores from 0 to 10. The mean bone densities were 987.95 ± 186.83 Hounsfield units (HU) for bone fragment and 473.55 ± 220.34 HU for bone dust (P < 0.001); the mean cosmetic scores were 9.5 for bone fragment and 5.7 for bone dust (P < 0.001). The use of autologous bone discs showed better results than bone dust for the reconstruction of cranial burr holes because of their lower degree of bone resorption and, consequently, better cosmetic results. The lack of donor site morbidity associated with procedural low cost qualifies the cortical autograft as the first choice for correcting cranial defects created by neurosurgical trephines.

  10. Comparative study between cortical bone graft versus bone dust for reconstruction of cranial burr holes

    PubMed Central

    Worm, Paulo V.; Ferreira, Nelson P.; Faria, Mario B.; Ferreira, Marcelo P.; Kraemer, Jorge L.; Collares, Marcus V. M.

    2010-01-01

    Background: As a consequence of the progressive evolution of neurosurgical techniques, there has been increasing concern with the esthetic aspects of burr holes. Therefore, the objective of this study was to compare the use of cortical bone graft and bone dust for correcting cranial deformities caused by neurosurgical trephines. Methods: Twenty-three patients were enrolled for cranial burr hole reconstruction with a 1-year follow-up. A total of 108 burr holes were treated; 36 burr holes were reconstructed with autogenous cortical bone discs (33.3%), and the remaining 72 with autogenous wet bone powder (66.6%). A trephine was specifically designed to produce this coin-shaped bone plug of 14 mm in diameter, which fit perfectly over the burr holes. The reconstructions were studied 12 months after the surgical procedure, using three-dimensional quantitative computed tomography. Additionally, general and plastic surgeons blinded for the study evaluated the cosmetic results of those areas, attributing scores from 0 to 10. Results: The mean bone densities were 987.95 ± 186.83 Hounsfield units (HU) for bone fragment and 473.55 ± 220.34 HU for bone dust (P < 0.001); the mean cosmetic scores were 9.5 for bone fragment and 5.7 for bone dust (P < 0.001). Conclusions: The use of autologous bone discs showed better results than bone dust for the reconstruction of cranial burr holes because of their lower degree of bone resorption and, consequently, better cosmetic results. The lack of donor site morbidity associated with procedural low cost qualifies the cortical autograft as the first choice for correcting cranial defects created by neurosurgical trephines. PMID:21206899

  11. A Mouse Model for Studying Nutritional Programming: Effects of Early Life Exposure to Soy Isoflavones on Bone and Reproductive Health.

    PubMed

    Ward, Wendy E; Kaludjerovic, Jovana; Dinsdale, Elsa C

    2016-05-11

    Over the past decade, our research group has characterized and used a mouse model to demonstrate that "nutritional programming" of bone development occurs when mice receive soy isoflavones (ISO) during the first days of life. Nutritional programming of bone development can be defined as the ability for diet during early life to set a trajectory for better or compromised bone health at adulthood. We have shown that CD-1 mice exposed to soy ISO during early neonatal life have higher bone mineral density (BMD) and greater trabecular inter-connectivity in long bones and lumbar spine at young adulthood. These skeletal sites also withstand greater forces before fracture. Because the chemical structure of ISO resembles that of 17-β-estradiol and can bind to estrogen receptors in reproductive tissues, it was prudent to expand analyses to include measures of reproductive health. This review highlights aspects of our studies in CD-1 mice to understand the early life programming effects of soy ISO on bone and reproductive health. Preclinical mouse models can provide useful data to help develop and guide the design of studies in human cohorts, which may, depending on findings and considerations of safety, lead to dietary interventions that optimize bone health.

  12. A Mouse Model for Studying Nutritional Programming: Effects of Early Life Exposure to Soy Isoflavones on Bone and Reproductive Health

    PubMed Central

    Ward, Wendy E.; Kaludjerovic, Jovana; Dinsdale, Elsa C.

    2016-01-01

    Over the past decade, our research group has characterized and used a mouse model to demonstrate that “nutritional programming” of bone development occurs when mice receive soy isoflavones (ISO) during the first days of life. Nutritional programming of bone development can be defined as the ability for diet during early life to set a trajectory for better or compromised bone health at adulthood. We have shown that CD-1 mice exposed to soy ISO during early neonatal life have higher bone mineral density (BMD) and greater trabecular inter-connectivity in long bones and lumbar spine at young adulthood. These skeletal sites also withstand greater forces before fracture. Because the chemical structure of ISO resembles that of 17-β-estradiol and can bind to estrogen receptors in reproductive tissues, it was prudent to expand analyses to include measures of reproductive health. This review highlights aspects of our studies in CD-1 mice to understand the early life programming effects of soy ISO on bone and reproductive health. Preclinical mouse models can provide useful data to help develop and guide the design of studies in human cohorts, which may, depending on findings and considerations of safety, lead to dietary interventions that optimize bone health. PMID:27187422

  13. Canine prostate models in preclinical studies of minimally invasive interventions: part II, benign prostatic hyperplasia models

    PubMed Central

    Báez-Díaz, Claudia; Sánchez-Margallo, Francisco Miguel

    2017-01-01

    Canine prostate is widely used as animal model in the preclinical evaluation of emerging therapeutic interventions. Spontaneous benign prostatic hyperplasia (BPH) is common in adult intact male dogs with two distinct pathological types: glandular and complex form of prostatic hyperplasia. The complex form of prostatic hyperplasia, usually occurring in older dogs, represents an ideal model because of its unique pathologic feature, including not only glandular hyperplasia but also an increase in prostate stromal components. The limited commercial availability of adult dogs with spontaneous BPH motivates experimentally induced BPH in young dogs. Hormone-induced canine BPH model has been well established with various hormonal treatment regimens and administration approaches. The goal of this review is to provide the veterinary background in spontaneous BPH in dogs, summarize the techniques in hormonal induction of canine BPH, and highlight the pathological and clinical limitations of the canine models that may lead to distinct therapeutic responses compared to clinical trials in humans. PMID:28725598

  14. [Vitamin K and bone quality].

    PubMed

    Hara, Kuniko; Akiyama, Yasuhiro

    2007-11-01

    Meta-analysis involving previous clinical studies showed that VK(2) decreased the incidence of fracture. In particular, the results based on the data on bone mineral density and fracture suggested that VK(2) improves bone quality. Preclinical studies regarding bone quality reported that VK(2) improved the trabecular microarchitecture (connectivity and width) in an ovariectomized model, and that VK(2) increased the bone strength without influencing the bone mineral content in a model fed a low-Mg diet and a vitamin C deficiency model, increasing the collagen level and proline hydroxylation. Thus, improvement in bone quality via actions on the bone geometry and collagen level/quality may be involved in a VK(2)-related decrease in the incidence of new fracture in clinical studies.

  15. [Fundamental study of blood and bone marrow].

    PubMed

    Miura, Ikuo

    2009-10-01

    The WHO classification incorporated recent advances of immunology, cytogenetics, and molecular biology, which developed from FAB classification based on cell morphology and cytochemistry. One of the most distinct changes was "AML with recurrent genetic abnormalities." The immunological and cytogenetic studies are required to apply the classification to hematopoietic and lymphoid neoplasms in addition to conventional examinations of the blood and bone marrow. The fundamentals of specimen collection, cell counts, morphologic analysis of blood cells, special stains and other laboratory studies were described in related to the management of myeloid leukemias.

  16. Preclinical Development of Ipilimumab and Nivolumab Combination Immunotherapy: Mouse Tumor Models, In Vitro Functional Studies, and Cynomolgus Macaque Toxicology

    PubMed Central

    Selby, Mark J.; Engelhardt, John J.; Johnston, Robert J.; Lu, Li-Sheng; Han, Minhua; Thudium, Kent; Yao, Dapeng; Quigley, Michael; Valle, Jose; Wang, Changyu; Chen, Bing; Cardarelli, Pina M.; Blanset, Diann; Korman, Alan J.

    2016-01-01

    The monoclonal antibodies ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1) have shown remarkable antitumor activity in an increasing number of cancers. When combined, ipilimumab and nivolumab have demonstrated superior activity in patients with metastatic melanoma (CHECKMATE-067). Here we describe the preclinical development strategy that predicted these clinical results. Synergistic antitumor activity in mouse MC38 and CT26 colorectal tumor models was observed with concurrent, but not sequential CTLA-4 and PD-1 blockade. Significant antitumor activity was maintained using a fixed dose of anti-CTLA-4 antibody with decreasing doses of anti-PD-1 antibody in the MC38 model. Immunohistochemical and flow cytometric analyses confirmed that CD3+ T cells accumulated at the tumor margin and infiltrated the tumor mass in response to the combination therapy, resulting in favorable effector and regulatory T-cell ratios, increased pro-inflammatory cytokine secretion, and activation of tumor-specific T cells. Similarly, in vitro studies with combined ipilimumab and nivolumab showed enhanced cytokine secretion in superantigen stimulation of human peripheral blood lymphocytes and in mixed lymphocyte response assays. In a cynomolgus macaque toxicology study, dose-dependent immune-related gastrointestinal inflammation was observed with the combination therapy; this response had not been observed in previous single agent cynomolgus studies. Together, these in vitro assays and in vivo models comprise a preclinical strategy for the identification and development of highly effective antitumor combination immunotherapies. PMID:27610613

  17. Combined targeting of EGFR-dependent and VEGF-dependent pathways: rationale, preclinical studies and clinical applications.

    PubMed

    Tortora, Giampaolo; Ciardiello, Fortunato; Gasparini, Giampietro

    2008-09-01

    Cellular heterogeneity, redundancy of molecular pathways and effects of the microenvironment contribute to the survival, motility and metastasis of cells in solid tumors. It is unlikely that tumors are entirely dependent on only one abnormally activated signaling pathway; consequently, treatment with an agent that interferes with a single target may be insufficient. Combined blockade of functionally linked and relevant multiple targets has become an attractive therapeutic strategy. The EGFR and ERBB2 (HER2) pathways and VEGF-dependent angiogenesis have a pivotal role in cancer pathogenesis and progression. Robust experimental evidence has shown that these pathways are functionally linked and has demonstrated a suggested role for VEGF in the acquired resistance to anti-ERBB drugs when these receptors are pharmacologically blocked. Combined inhibition of ERBB and VEGF signaling interferes with a molecular feedback loop responsible for acquired resistance to anti-ERBB agents and promotes apoptosis while ablating tumor-induced angiogenesis. To this aim, either two agents highly selective against VEGF and ERBB respectively, or, alternatively, a single multitargeted agent, can be used. Preclinical studies have proven the efficacy of both these approaches and early clinical studies have provided encouraging results. This Review discusses the experimental rationale for, preclinical studies of and clinical trials on combined blockade of ERBB and VEGF signaling.

  18. A method for comparing intra-tumoural radioactivity uptake heterogeneity in preclinical positron emission tomography studies.

    PubMed

    Grafström, Jonas; Ahlzén, Hanna-Stina; Stone-Elander, Sharon

    2015-12-01

    Non-uniformity influences the interpretation of nuclear medicine based images and consequently their use in treatment planning and monitoring. However, no standardised method for evaluating and ranking heterogeneity exists. Here, we have developed a general algorithm that provides a ranking and a visualisation of the heterogeneity in small animal positron emission tomography (PET) images. The code of the algorithm was written using the Matrix Laboratory software (MATLAB). Parameters known to influence the heterogeneity (distances between deviating peaks, gradients and size compensations) were incorporated into the algorithm. All data matrices were mathematically constructed in the same format with the aim of maintaining overview and control. Histograms visualising the spread and frequency of contributions to the heterogeneity were also generated. The construction of the algorithm was tested using mathematically generated matrices and by varying post-processing parameters. It was subsequently applied in comparisons of radiotracer uptake in preclinical images in human head and neck carcinoma and endothelial and ovarian carcinoma xenografts. Using the developed algorithm, entire tissue volumes could be assessed and gradients could be handled in an indirect manner. Similar-sized volumes could be compared without modifying the algorithm. Analyses of the distribution of different tracers gave results that were generally in accordance with single plane preclinical images, indicating that it could appropriately handle comparisons of targeting vs. non-targeting tracers and also for different target levels. Altering the reconstruction algorithm, pixel size, tumour ROI volumes and lower cut-off limits affected the calculated heterogeneity factors in expected directions but did not reverse conclusions about which tumour was more or less heterogeneous. The algorithm constructed is an objective and potentially user-friendly tool for one-to-one comparisons of heterogeneity in

  19. Mouse models for studying prostate cancer bone metastasis

    PubMed Central

    Dai, Jinlu; Hensel, Janine; Wang, Ning; Kruithof-de Julio, Marianna; Shiozawa, Yusuke

    2016-01-01

    Once tumor cells metastasize to the bone, the prognosis for prostate cancer patients is generally very poor. The mechanisms involved in bone metastasis, however, remain elusive, because of lack of relevant animal models. In this manuscript, we describe step-by-step protocols for the xenograft mouse models that are currently used for studying prostate cancer bone metastasis. The different routes of tumor inoculation (intraosseous, intracardiac, intravenous and orthotopic) presented are useful for exploring the biology of bone metastasis. PMID:26916039

  20. Investigation of a pre-clinical mandibular bone notch defect model in miniature pigs: clinical computed tomography, micro-computed tomography, and histological evaluation

    PubMed Central

    2016-01-01

    Objectives To validate a critical-size mandibular bone defect model in miniature pigs. Materials and Methods Bilateral notch defects were produced in the mandible of dentally mature miniature pigs. The right mandibular defect remained untreated while the left defect received an autograft. Bone healing was evaluated by computed tomography (CT) at 4 and 16 weeks, and by micro-CT and non-decalcified histology at 16 weeks. Results In both the untreated and autograft treated groups, mineralized tissue volume was reduced significantly at 4 weeks post-surgery, but was comparable to the pre-surgery levels after 16 weeks. After 16 weeks, CT analysis indicated that significantly greater bone was regenerated in the autograft treated defect than in the untreated defect (P=0.013). Regardless of the treatment, the cortical bone was superior to the defect remodeled over 16 weeks to compensate for the notch defect. Conclusion The presence of considerable bone healing in both treated and untreated groups suggests that this model is inadequate as a critical-size defect. Despite healing and adaptation, the original bone geometry and quality of the pre-injured mandible was not obtained. On the other hand, this model is justified for evaluating accelerated healing and mitigating the bone remodeling response, which are both important considerations for dental implant restorations. PMID:26904491

  1. Impact of a Differential Learning Approach on Practical Exam Performance: A Controlled Study in a Preclinical Dental Course.

    PubMed

    Pabel, Sven-Olav; Pabel, Anne-Kathrin; Schmickler, Jan; Schulz, Xenia; Wiegand, Annette

    2017-09-01

    The aim of this study was to evaluate if differential learning in a preclinical dental course impacted the performance of dental students in a practical exam (preparation of a gold partial crown) immediately after the training session and 20 weeks later compared to conventional learning. This controlled study was performed in a preclinical course in operative dentistry at a dental school in Germany. Third-year students were trained in preparing gold partial crowns by using either the conventional learning (n=41) or the differential learning approach (n=32). The differential learning approach consisted of 20 movement exercises with a continuous change of movement execution during the learning session, while the conventional learning approach was mainly based on repetition, a methodological series of exercises, and correction of preparations during the training phase. Practical exams were performed immediately after the training session (T1) and 20 weeks later (T2, retention test). Preparations were rated by four independent and blinded examiners. At T1, no significant difference between the performance (exam passed) of the two groups was detected (conventional learning: 54.3%, differential learning: 68.0%). At T2, significantly more students passed the exam when trained by the differential learning approach (68.8%) than by the conventional learning approach (18.9%). Interrater reliability was moderate (Kappa: 0.57, T1) or substantial (Kappa: 0.67, T2), respectively. These results suggest that a differential learning approach can increase the manual skills of dental students.

  2. Preclinical toxicity evaluation of AAV for pain: evidence from human AAV studies and from the pharmacology of analgesic drugs.

    PubMed

    Pleticha, Josef; Heilmann, Lukas F; Evans, Christopher H; Asokan, Aravind; Samulski, Richard Jude; Beutler, Andreas S

    2014-09-02

    Gene therapy with adeno-associated virus (AAV) has advanced in the last few years from promising results in animal models to >100 clinical trials (reported or under way). While vector availability was a substantial hurdle a decade ago, innovative new production methods now routinely match the scale of AAV doses required for clinical testing. These advances may become relevant to translational research in the chronic pain field. AAV for pain targeting the peripheral nervous system was proven to be efficacious in rodent models several years ago, but has not yet been tested in humans. The present review addresses the steps needed for translation of AAV for pain from the bench to the bedside focusing on pre-clinical toxicology. We break the potential toxicities into three conceptual categories of risk: First, risks related to the delivery procedure used to administer the vector. Second, risks related to AAV biology, i.e., effects of the vector itself that may occur independently of the transgene. Third, risks related to the effects of the therapeutic transgene. To identify potential toxicities, we consulted the existing evidence from AAV gene therapy for other nervous system disorders (animal toxicology and human studies) and from the clinical pharmacology of conventional analgesic drugs. Thereby, we identified required preclinical studies and charted a hypothetical path towards a future phase I/II clinical trial in the oncology-palliative care setting.

  3. Preclinical toxicity evaluation of AAV for pain: evidence from human AAV studies and from the pharmacology of analgesic drugs

    PubMed Central

    2014-01-01

    Gene therapy with adeno-associated virus (AAV) has advanced in the last few years from promising results in animal models to >100 clinical trials (reported or under way). While vector availability was a substantial hurdle a decade ago, innovative new production methods now routinely match the scale of AAV doses required for clinical testing. These advances may become relevant to translational research in the chronic pain field. AAV for pain targeting the peripheral nervous system was proven to be efficacious in rodent models several years ago, but has not yet been tested in humans. The present review addresses the steps needed for translation of AAV for pain from the bench to the bedside focusing on pre-clinical toxicology. We break the potential toxicities into three conceptual categories of risk: First, risks related to the delivery procedure used to administer the vector. Second, risks related to AAV biology, i.e., effects of the vector itself that may occur independently of the transgene. Third, risks related to the effects of the therapeutic transgene. To identify potential toxicities, we consulted the existing evidence from AAV gene therapy for other nervous system disorders (animal toxicology and human studies) and from the clinical pharmacology of conventional analgesic drugs. Thereby, we identified required preclinical studies and charted a hypothetical path towards a future phase I/II clinical trial in the oncology-palliative care setting. PMID:25183392

  4. Pharmacokinetics and tolerability of NSC23925b, a novel P-glycoprotein inhibitor: preclinical study in mice and rats

    PubMed Central

    Gao, Yan; Shen, Jacson K.; Choy, Edwin; Zhang, Zhan; Mankin, Henry J.; Hornicek, Francis J.; Duan, Zhenfeng

    2016-01-01

    Overexpression of P-glycoprotein (Pgp) increases multidrug resistance (MDR) in cancer, which greatly impedes satisfactory clinical treatment and outcomes of cancer patients. Due to unknown pharmacokinetics, the use of Pgp inhibitors to overcome MDR in the clinical setting remains elusive despite promising in vitro results. The purpose of our current preclinical study is to investigate the pharmacokinetics and tolerability of NSC23925b, a novel and potent P-glycoprotein inhibitor, in rodents. Plasma pharmacokinetic studies of single-dose NSC23925b alone or in combination with paclitaxel or doxorubicin were conducted in male BALB/c mice and Sprague-Dawley rats. Additionally, inhibition of human cytochrome P450 (CYP450) by NSC23925b was examined in vitro. Finally, the maximum tolerated dose (MTD) of NSC23925b was determined. NSC23925b displayed favorable pharmacokinetic profiles after intraperitoneal/intravenous (I.P./I.V.) injection alone or combined with chemotherapeutic drugs. The plasma pharmacokinetic characteristics of the chemotherapy drugs were not affected when co-administered with NSC23925b. All the animals tolerated the I.P./I.V. administration of NSC23925b. Moreover, the enzymatic activity of human CYP450 was not inhibited by NSC23925b. Our results demonstrated that Pgp inhibitor NSC23925b exhibits encouraging preclinical pharmacokinetic characteristics and limited toxicity in vivo. NSC23925b has the potential to treat cancer patients with MDR in the future. PMID:27157103

  5. Focused ultrasound-induced blood-brain barrier opening to enhance temozolomide delivery for glioblastoma treatment: a preclinical study.

    PubMed

    Wei, Kuo-Chen; Chu, Po-Chun; Wang, Hay-Yan Jack; Huang, Chiung-Yin; Chen, Pin-Yuan; Tsai, Hong-Chieh; Lu, Yu-Jen; Lee, Pei-Yun; Tseng, I-Chou; Feng, Li-Ying; Hsu, Peng-Wei; Yen, Tzu-Chen; Liu, Hao-Li

    2013-01-01

    The purpose of this study is to assess the preclinical therapeutic efficacy of magnetic resonance imaging (MRI)-monitored focused ultrasound (FUS)-induced blood-brain barrier (BBB) disruption to enhance Temozolomide (TMZ) delivery for improving Glioblastoma Multiforme (GBM) treatment. MRI-monitored FUS with microbubbles was used to transcranially disrupt the BBB in brains of Fisher rats implanted with 9L glioma cells. FUS-BBB opening was spectrophotometrically determined by leakage of dyes into the brain, and TMZ was quantitated in cerebrospinal fluid (CSF) and plasma by LC-MS\\MS. The effects of treatment on tumor progression (by MRI), animal survival and brain tissue histology were investigated. Results demonstrated that FUS-BBB opening increased the local accumulation of dyes in brain parenchyma by 3.8-/2.1-fold in normal/tumor tissues. Compared to TMZ alone, combined FUS treatment increased the TMZ CSF/plasma ratio from 22.7% to 38.6%, reduced the 7-day tumor progression ratio from 24.03 to 5.06, and extended the median survival from 20 to 23 days. In conclusion, this study provided preclinical evidence that FUS BBB-opening increased the local concentration of TMZ to improve the control of tumor progression and animal survival, suggesting its clinical potential for improving current brain tumor treatment.

  6. Application of accelerator mass spectrometry to macromolecules: preclinical pharmacokinetic studies on a polybisphosphonate.

    PubMed

    Salehpour, Mehran; Håkansson, Karl; Höglund, Urban; Grahn-Westin, Annika; Nilsson, Sten; Márquez, Marcela; Possnert, Göran; Holmberg, Anders R

    2011-09-15

    Data on the use of accelerator mass spectrometry (AMS) in conjunction with in vivo studies of macromolecular drugs are scarce. The present study shows the versatility of this technique when investigating the pharmacokinetics (PK) of a macromolecular drug candidate, a polybisphosphonate conjugate (ODX). The aforementioned is a polymer (molecular weight ~30 kDa) constituting a carbohydrate backbone with covalently linked ligands (aldendronate and aminoguanidine) and is intended for treatment of osteoporosis and the therapy of bone metastasis from prostate cancer. The conjugate is prepared through partial oxidation of the carbohydrate and sequential coupling of the ligands by reductive amination. (14)C was incorporated in the conjugate by means of coupling a commercially available (14)C-lysine in the conjugation sequence. Fifteen rats were injected intravenously with (14)C-labelled ODX (150 µg, 14 Bq/rat) and blood samples were collected at 1, 2, 4, 6, and 24 h post-injection (3 rats/time point). Liver, spleen and kidney samples were collected at 4 and 24 h post-injection. Blood from each time point (triplicate) were collected for AMS measurement determining the isotopic ratio ((14)C/(12)C) and consequently the drug concentration in blood. ODX showed a transient presence in blood circulation; 93% of the total dose was cleared from the circulation within 1 h. The half-life after 1 h was estimated to be about 3 h; 0.7% of the administered (14)C dose of ODX remained in circulation after 24 h. The major (14)C accumulation was in the liver, the spleen and the kidneys indicating the probable route of metabolism and excretion. This study demonstrates the versatility of AMS for pharmacological in vivo studies of macromolecules. Labelling with (14)C is relatively simple, inexpensive and the method requires minimal radioactivity, eliminating the need for radioprotection precautions in contrast to methods using scintillation counting. Copyright © 2011 John

  7. Automated assessment of bone changes in cross-sectional micro-CT studies of murine experimental osteoarthritis

    PubMed Central

    Vincent, Tonia L.; Marenzana, Massimo

    2017-01-01

    Objective The degradation of articular cartilage, which characterises osteoarthritis (OA), is usually paired with excessive bone remodelling, including subchondral bone sclerosis, cysts, and osteophyte formation. Experimental models of OA are widely used to investigate pathogenesis, yet few validated methodologies for assessing periarticular bone morphology exist and quantitative measurements are limited by manual segmentation of micro-CT scans. The aim of this work was to chart the temporal changes in periarticular bone in murine OA by novel, automated micro-CT methods. Methods OA was induced by destabilisation of the medial meniscus (DMM) in 10-week old male mice and disease assessed cross-sectionally from 1- to 20-weeks post-surgery. A novel approach was developed to automatically segment subchondral bone compartments into plate and trabecular bone in micro-CT scans of tibial epiphyses. Osteophyte volume, as assessed by shape differences using 3D image registration, and by measuring total epiphyseal volume was performed. Results Significant linear and volumetric structural modifications in subchondral bone compartments and osteophytes were measured from 4-weeks post-surgery and showed progressive changes at all time points; by 20 weeks, medial subchondral bone plate thickness increased by 160±19.5 μm and the medial osteophyte grew by 0.124±0.028 μm3. Excellent agreement was found when automated measurements were compared with manual assessments. Conclusion Our automated methods for assessing bone changes in murine periarticular bone are rapid, quantitative, and highly accurate, and promise to be a useful tool in future preclinical studies of OA progression and treatment. The current approaches were developed specifically for cross-sectional micro-CT studies but could be applied to longitudinal studies. PMID:28334010

  8. Bone induction using demineralized bone in the rabbit femur: a long-term study.

    PubMed

    Concannon, M J; Boschert, M T; Puckett, C L

    1997-06-01

    While traditional bone grafting is the standard for replacement of segmental bony defects, alternative options (avoiding morbidity of autologous grafts) are attractive and continue to be sought. This study attempted to determine whether demineralized bone powder could be used reliably to replace a significant bony deficit at a weight-bearing site. The long-term functional characteristics of this induced bone were analyzed to determine whether it maintained its strength and shape and reacted normally to physiologic stress over an extended period of time (12 months). In 55 New Zealand White rabbits, a 1-cm length of femur was removed (approximately 20 percent of the total length of the rabbit femur). The femur was then reconstructed with a titanium mandibular plate, leaving the gap intact. In 38 of the animals, this gap was filled with demineralized bone powder in an attempt to induce bone to form across the defect. In group 1 (n = 23), the mandibular plate remained in place for the duration of the study (12 months). In group 2 (n = 15), the plate was removed 8 weeks after placement of the demineralized bone powder, and the animals were followed for an additional 12 months. In group 3 (n = 10), nothing was placed within the bony gap. In group 4 (n = 7), the gap was repaired with autologous bone graft. All the animals that received demineralized bone powder completely filled the osteotomy gap with new bone within 6 to 8 weeks after implantation. None of control group 3 formed bone across the gap (p < 0.001). Eighty-six percent of control group 4 (autologous bone graft) successfully formed bone across the osteotomy gap. In addition, 90 percent of control group 3 had hardware failure within 8 weeks after surgery compared with 0 percent (0 of 38) of the group that received demineralized bone powder (p < 0.001). In group 1, analysis after 12 months revealed that the bone formed ultimately became thin and easily fractured, most likely because of shielding from stress

  9. Pharmacological and Toxicological Study of Maytenus ilicifolia Leaf Extract. Part I - Preclinical Studies.

    PubMed

    Tabach, Ricardo; Duarte-Almeida, Joaquim M; Carlini, Elisaldo A

    2017-06-01

    One of the Brazilians medicinal plants most cited in ethnopharmacological surveys for the treatment of ulcers and gastric diseases was evaluated for its efficacy and toxicity. Maytenus ilicifolia leaf extract (MIE) was acutely and chronically (180 days) administered to rats, mice, and dogs. Acute tests were antiulcer effect and toxicological trials (observational pharmacological screening, LD50, motor coordination, sleeping time and motor activity). Chronic tests were the following: weight gain/loss and behavioral parameters in rats and mice; estrus cycle, effects on fertility, and teratogenic studies in rats and mutagenic features in mice, in addition to the Ames and micronucleus test. The following parameters were assessed in dogs: weight gain/loss, general physical conditions, water/food consumption, and anatomopathological examination of the organs subsequent to the 180-day treatment. The results showed a clear antiulcer activity for MIE from 70 mg/kg and an absence of toxicological effects in the three animal species, even if given in high doses or over a long period. The present results confirm the antiulcer property and absence of toxicological effects in three animal species of MIE, which is in line with its current popular medicinal use. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  10. Latent Structure and Factorial Invariance of a Neuropsychological Test Battery for the Study of Preclinical Alzheimer’s Disease

    PubMed Central

    Dowling, N. Maritza; Hermann, Bruce; La Rue, Asenath; Sager, Mark A.

    2010-01-01

    Objective To examine the latent structure of a test battery currently being used in a longitudinal study of asymptomatic middle-aged adults with a parental history of Alzheimer’s disease (AD) and test the invariance of the factor solution across subgroups defined by selected demographic variables and known genetic risk factors for AD. Method An exploratory factor analysis (EFA) and a sequence of confirmatory factor analyses (CFA) were conducted on 24 neuropsychological measures selected to provide a comprehensive estimate of cognitive abilities most likely to be affected in preclinical AD. Once the underlying latent model was defined and the structural validity established through model comparisons, a multi-group confirmatory factor analysis model was used to test for factorial invariance across groups. Results The EFA solution revealed a factor structure consisting of 5 constructs: verbal ability, visuo-spatial ability, speed & executive function, working memory, and verbal learning & memory. The CFA models provided support for the hypothesized 5-factor structure. Results indicated factorial invariance of the model across all groups examined. Conclusions Collectively, the results suggested a relatively strong psychometric basis for using the factor structure in clinical samples that match the characteristics of this cohort. This confirmed an invariant factor structure should prove useful in research aimed to detect the earliest cognitive signature of preclinical AD in similar middle aged cohorts. PMID:21038965

  11. Apparent diffusion coefficient is highly reproducible on preclinical imaging systems: Evidence from a seven-center multivendor study.

    PubMed

    Doblas, Sabrina; Almeida, Gilberto S; Blé, François-Xavier; Garteiser, Philippe; Hoff, Benjamin A; McIntyre, Dominick J O; Wachsmuth, Lydia; Chenevert, Thomas L; Faber, Cornelius; Griffiths, John R; Jacobs, Andreas H; Morris, David M; O'Connor, James P B; Robinson, Simon P; Van Beers, Bernard E; Waterton, John C

    2015-12-01

    To evaluate between-site agreement of apparent diffusion coefficient (ADC) measurements in preclinical magnetic resonance imaging (MRI) systems. A miniaturized thermally stable ice-water phantom was devised. ADC (mean and interquartile range) was measured over several days, on 4.7T, 7T, and 9.4T Bruker, Agilent, and Magnex small-animal MRI systems using a common protocol across seven sites. Day-to-day repeatability was expressed as percent variation of mean ADC between acquisitions. Cross-site reproducibility was expressed as 1.96 × standard deviation of percent deviation of ADC values. ADC measurements were equivalent across all seven sites with a cross-site ADC reproducibility of 6.3%. Mean day-to-day repeatability of ADC measurements was 2.3%, and no site was identified as presenting different measurements than others (analysis of variance [ANOVA] P = 0.02, post-hoc test n.s.). Between-slice ADC variability was negligible and similar between sites (P = 0.15). Mean within-region-of-interest ADC variability was 5.5%, with one site presenting a significantly greater variation than the others (P = 0.0013). Absolute ADC values in preclinical studies are comparable between sites and equipment, provided standardized protocols are employed. © 2015 Wiley Periodicals, Inc.

  12. Engineering a humanized bone organ model in mice to study bone metastases.

    PubMed

    Martine, Laure C; Holzapfel, Boris M; McGovern, Jacqui A; Wagner, Ferdinand; Quent, Verena M; Hesami, Parisa; Wunner, Felix M; Vaquette, Cedryck; De-Juan-Pardo, Elena M; Brown, Toby D; Nowlan, Bianca; Wu, Dan Jing; Hutmacher, Cosmo Orlando; Moi, Davide; Oussenko, Tatiana; Piccinini, Elia; Zandstra, Peter W; Mazzieri, Roberta; Lévesque, Jean-Pierre; Dalton, Paul D; Taubenberger, Anna V; Hutmacher, Dietmar W

    2017-04-01

    Current in vivo models for investigating human primary bone tumors and cancer metastasis to the bone rely on the injection of human cancer cells into the mouse skeleton. This approach does not mimic species-specific mechanisms occurring in human diseases and may preclude successful clinical translation. We have developed a protocol to engineer humanized bone within immunodeficient hosts, which can be adapted to study the interactions between human cancer cells and a humanized bone microenvironment in vivo. A researcher trained in the principles of tissue engineering will be able to execute the protocol and yield study results within 4-6 months. Additive biomanufactured scaffolds seeded and cultured with human bone-forming cells are implanted ectopically in combination with osteogenic factors into mice to generate a physiological bone 'organ', which is partially humanized. The model comprises human bone cells and secreted extracellular matrix (ECM); however, other components of the engineered tissue, such as the vasculature, are of murine origin. The model can be further humanized through the engraftment of human hematopoietic stem cells (HSCs) that can lead to human hematopoiesis within the murine host. The humanized organ bone model has been well characterized and validated and allows dissection of some of the mechanisms of the bone metastatic processes in prostate and breast cancer.

  13. Addictive potential of modafinil and cross-sensitization with cocaine: a pre-clinical study.

    PubMed

    Wuo-Silva, Raphael; Fukushiro, Daniela F; Borçoi, Aline R; Fernandes, Helaine A; Procópio-Souza, Roberta; Hollais, André W; Santos, Renan; Ribeiro, Luciana T C; Corrêa, Jussara M R M; Talhati, Fernanda; Saito, Luis P; Aramini, Tatiana C F; Kameda, Sonia R; Bittencourt, Lia R A; Tufik, Sergio; Frussa-Filho, Roberto

    2011-10-01

    Repeated or even a single exposure to drugs of abuse can lead to persistent locomotor sensitization, which is the result of an abundance of neuroplastic changes occurring within the circuitry involved in motivational behavior and is thought to play a key role in certain aspects of drug addiction. There is substantial controversy about the addictive potential of modafinil, a wake-promoting drug used to treat narcolepsy that is increasingly being used as a cognitive enhancer and has been proposed as a pharmacotherapy for cocaine dependence. Male mice were used to investigate the ability of modafinil to induce locomotor sensitization after repeated or single administration in mice. Bidirectional cross-sensitization with cocaine and modafinil-induced conditioned place preference were also evaluated. Both repeated and single exposure to moderate and high doses of modafinil produced a pronounced locomotor sensitization that cross-sensitized in a bidirectional way with cocaine. Remarkably, when cocaine and modafinil were repeatedly administered sequentially, their behavioral sensitization was additive. Supporting these behavioral sensitization data, modafinil produced a pronounced conditioned place preference in the mouse. Taken together, the present findings provide pre-clinical evidence for the addictive potential of modafinil. Our data also strongly suggest that similar neural substrates are involved in the psychomotor/rewarding effects of modafinil and cocaine.

  14. Targeted Toxins for Glioblastoma Multiforme: pre-clinical studies and clinical implementation

    PubMed Central

    Candolfi, Marianela; Kroeger, Kurt M.; Xiong, Weidong; Liu, Chunyan; Puntel, Mariana; Yagiz, Kader; Ghulam Muhammad, AKM; Mineharu, Yohei; Foulad, David; Wibowo, Mia; Assi, Hikmat; Baker, Gregory J.; Lowenstein, Pedro R.; Castro, Maria G.

    2011-01-01

    Glioblastoma multiforme (GBM) is most common primary brain tumor in adults. GBM is very aggressive due to its poor cellular differentiation and invasiveness, which makes complete surgical resection virtually impossible. Therefore, GBM’s invasive nature as well as its intrinsic resistance to current treatment modalities makes it a unique therapeutic challenge. Extensive examination of human GBM specimens has uncovered that these tumors overexpress a variety of receptors that are virtually absent in the surrounding non-neoplastic brain. Human GBMs overexpress receptors for cytokines, growth factors, ephrins, urokinase-type plasminogen activator (uPA), and transferrin, which can be targeted with high specificity by linking their ligands with highly cytotoxic molecules, such as Diptheria toxin and Pseudomonas exotoxin A. We review the preclinical development and clinical translation of targeted toxins for GBM. In view of the clinical experience, we conclude that although these are very promising therapeutic modalities for GBM patients, efforts should be focused on improving the delivery systems utilized in order to achieve better distribution of the immuno-toxins in the tumor/resection cavity. Delivery of targeted toxins using viral vectors would also benefit enormously from improved strategies for local delivery. PMID:21707497

  15. Therapeutic vaccination and immunomodulation in the treatment of chronic hepatitis B: preclinical studies in the woodchuck.

    PubMed

    Kosinska, Anna D; Liu, Jia; Lu, Mengji; Roggendorf, Michael

    2015-02-01

    Infection with hepatitis B virus (HBV) may lead to subclinical, acute or chronic hepatitis. In the prevaccination era, HBV infections were endemic due to frequent mother to child transmission in large regions of the world. However, there are still estimated 240 million chronic HBV carriers today and ca. 620,000 patients die per year due to HBV-related liver diseases. Recommended treatment of chronic hepatitis B with interferon-α and/or nucleos(t)ide analogues does not lead to satisfactory results. Induction of HBV-specific T cells by therapeutic vaccination or immunomodulation may be an innovative strategy to overcome virus persistence. Vaccination with commercially available HBV vaccines in patients with or without therapeutic reduction of viral load did not result in effective immune control of HBV infection, suggesting that combination of antiviral treatment with new formulations of therapeutic vaccines is needed. The woodchuck (Marmota monax) and its HBV-like woodchuck hepatitis virus are a useful preclinical animal model for developing new therapeutic approaches in chronic hepadnaviral infections. Several innovative approaches combining antiviral treatments using nucleos(t)ide analogues, with prime-boost vaccination using DNA vaccines, new hepadnaviral antigens or recombinant adenoviral vectors were tested in the woodchuck model. In this review, we summarize these encouraging results obtained with these therapeutic vaccines. In addition, we present potential innovations in immunostimulatory strategies by blocking the interaction of the inhibitory programmed death receptor 1 with its ligand in this animal model.

  16. A Preclinical Study Evaluating AAVrh10-Based Gene Therapy for Sanfilippo Syndrome.

    PubMed

    Winner, Leanne K; Beard, Helen; Hassiotis, Sofia; Lau, Adeline A; Luck, Amanda J; Hopwood, John J; Hemsley, Kim M

    2016-05-01

    Mucopolysaccharidosis type IIIA (MPS IIIA) is predominantly a disorder of the central nervous system, caused by a deficiency of sulfamidase (SGSH) with subsequent storage of heparan sulfate-derived oligosaccharides. No widely available therapy exists, and for this reason, a mouse model has been utilized to carry out a preclinical assessment of the benefit of intraparenchymal administration of a gene vector (AAVrh10-SGSH-IRES-SUMF1) into presymptomatic MPS IIIA mice. The outcome has been assessed with time, measuring primary and secondary storage material, neuroinflammation, and intracellular inclusions, all of which appear as the disease progresses. The vector resulted in predominantly ipsilateral distribution of SGSH, with substantially less detected in the contralateral hemisphere. Vector-derived SGSH enzyme improved heparan sulfate catabolism, reduced microglial activation, and, after a time delay, ameliorated GM3 ganglioside accumulation and halted ubiquitin-positive lesion formation in regions local to, or connected by projections to, the injection site. Improvements were not observed in regions of the brain distant from, or lacking connections with, the injection site. Intraparenchymal gene vector administration therefore has therapeutic potential provided that multiple brain regions are targeted with vector, in order to achieve widespread enzyme distribution and correction of disease pathology.

  17. Effect of Previous Irradiation on Vascular Thrombosis of Microsurgical Anastomosis: A Preclinical Study in Rats.

    PubMed

    Barrera-Ochoa, Sergi; Gallardo-Calero, Irene; López-Fernández, Alba; Romagosa, Cleofe; Vergés, Ramona; Aguirre-Canyadell, Marius; Soldado, Francisco; Velez, Roberto

    2016-11-01

    The objective of the present investigation was to compare the effect of neoadjuvant irradiation on the microvascular anastomosis in cervical bundle using an experimental model in rats. One hundred forty male Sprague-Dawley rats were allocated into 4 groups: group I, control, arterial microanastomosis; group II, control, venous microanastomosis; group III, arterial microanastomosis with previous irradiation (20 Gy); and group IV, venous microanastomosis with previous irradiation (20 Gy). Clinical parameters, technical values of anastomosis, patency, and histopathological parameters were evaluated. Irradiated groups (III and IV) and vein anastomosis groups (II and IV) showed significantly increased technical difficulties. Group IV showed significantly reduced patency rates (7/35) when compared with the control group (0/35). Radiotherapy significantly decreased the patency rates of the vein (7/35) when compared with the artery (1/35). Groups III and IV showed significantly reduced number of endothelial cells and also showed the presence of intimal thickening and adventitial fibrosis as compared with the control group. Neoadjuvant radiotherapy reduces the viability of the venous anastomosis in a preclinical rat model with a significant increase in the incidence of vein thrombosis.

  18. Effect of Previous Irradiation on Vascular Thrombosis of Microsurgical Anastomosis: A Preclinical Study in Rats

    PubMed Central

    Gallardo-Calero, Irene; López-Fernández, Alba; Romagosa, Cleofe; Vergés, Ramona; Aguirre-Canyadell, Marius; Soldado, Francisco; Velez, Roberto

    2016-01-01

    Background: The objective of the present investigation was to compare the effect of neoadjuvant irradiation on the microvascular anastomosis in cervical bundle using an experimental model in rats. Methods: One hundred forty male Sprague–Dawley rats were allocated into 4 groups: group I, control, arterial microanastomosis; group II, control, venous microanastomosis; group III, arterial microanastomosis with previous irradiation (20 Gy); and group IV, venous microanastomosis with previous irradiation (20 Gy). Clinical parameters, technical values of anastomosis, patency, and histopathological parameters were evaluated. Results: Irradiated groups (III and IV) and vein anastomosis groups (II and IV) showed significantly increased technical difficulties. Group IV showed significantly reduced patency rates (7/35) when compared with the control group (0/35). Radiotherapy significantly decreased the patency rates of the vein (7/35) when compared with the artery (1/35). Groups III and IV showed significantly reduced number of endothelial cells and also showed the presence of intimal thickening and adventitial fibrosis as compared with the control group. Conclusion: Neoadjuvant radiotherapy reduces the viability of the venous anastomosis in a preclinical rat model with a significant increase in the incidence of vein thrombosis. PMID:27975009

  19. A comparative study of calcium sulfate artificial bone graft versus allograft in the reconstruction of bone defect after tumor curettage.

    PubMed

    Yang, Yongkun; Niu, Xiaohui; Zhang, Qing; Hao, Lin; Ding, Yi; Xu, Hairong

    2014-01-01

    Cavity reconstruction after benign bone tumor removal is varied and controversial. Allograft is widely used but is associated with complications. New bone substitutes, such as calcium sulfate artificial bone, have been introduced for bone tumor operation. However, the bone healing response of artificial bone has not been compared with allograft bone. We therefore compared calcium sulfate grafts (study group) with bone allografts (control group) for the treatment of benign bone tumors. We retrospectively reviewed 50 patients who underwent calcium sulfate reconstruction and 50 patients who underwent allograft cancellous bone reconstruction. The two groups were well matched. The mean follow-up time of the study group was 19.9 (12-55) months. We investigated bone healing response, complications, and factors affecting bone healing. At the last follow-up, 84% (42/50) of cases in the study group and 62% (31/50) of cases in the control group had achieved clinical healing (P = 0.013). The initial healing rate showed no significant difference between the two groups (100% vs. 96%, P = 0.153). The mean healing times for calcium sulfate and allograft bone were 9.6 (3-42) months and 13.8 (3-36) months, respectively (P < 0.01). Complications in the study group were minor and resolved. Implant volume was a significant factor affecting bone healing. The calcium sulfate bone substitute showed a satisfactory healing outcome and safety profile in reconstruction of bone defects after benign bone tumor curettage, especially in smaller cavities.

  20. Bone

    NASA Astrophysics Data System (ADS)

    Helmberger, Thomas K.; Hoffmann, Ralf-Thorsten

    The typical clinical signs in bone tumours are pain, destruction and destabilization, immobilization, neurologic deficits, and finally functional impairment. Primary malignant bone tumours are a rare entity, accounting for about 0.2% of all malignancies. Also benign primary bone tumours are in total rare and mostly asymptomatic. The most common symptomatic benign bone tumour is osteoid osteoma with an incidence of 1:2000.

  1. Anticancer Potential of Citrus Juices and Their Extracts: A Systematic Review of Both Preclinical and Clinical Studies

    PubMed Central

    Cirmi, Santa; Maugeri, Alessandro; Ferlazzo, Nadia; Gangemi, Sebastiano; Calapai, Gioacchino; Schumacher, Udo; Navarra, Michele

    2017-01-01

    Background: During the last decades, a huge body of evidence has been accumulated suggesting that Citrus fruits and their juices might have a role in preventing many diseases including cancer. Objective: To summarize the numerous evidences on the potential of Citrus juices and their extracts as anticancer agents. Data sources: A systematic review of articles written in English using MEDLINE (1946-present), EMBASE (1974-present) and Web of Sciences (1970-present) was performed independently by two reviewers. Search terms included Citrus, Citrus aurantifolia, Citrus sinensis, Citrus paradisi, Citrus fruits, Citrus fruits extract, cancer, neoplasm, neoplasia, tumor, metastasis, carcinogenesis, proliferation. The last search was performed on March 16th, 2017. Study selection: Study selection and systematic review were carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Prior to the beginning of the review, Authors defined a checklist for inclusion criteria, thus including articles which meet the following: (i) published on peer-reviewed scientific journals; (ii) Citrus juice used alone; (iii) extracts derived from Citrus juice; (iii) for preclinical studies, an exposure time to Citrus juices and their extracts more than 24 h. Reviews, meta-analyses, conference abstracts and book chapters were excluded. Data extraction: Three reviewers independently performed the extraction of articles. Data synthesis: 22 papers met our inclusion criteria and were eligible for inclusion in the final review. According to the kind of study, the selected ones were further divided in preclinical (n = 20) and observational (n = 2) studies. Conclusion: The studies discussed in this review strongly corroborate the role of Citrus juices and their derivatives as potential resource against cancer. PMID:28713272

  2. Anticancer Potential of Citrus Juices and Their Extracts: A Systematic Review of Both Preclinical and Clinical Studies.

    PubMed

    Cirmi, Santa; Maugeri, Alessandro; Ferlazzo, Nadia; Gangemi, Sebastiano; Calapai, Gioacchino; Schumacher, Udo; Navarra, Michele

    2017-01-01

    Background: During the last decades, a huge body of evidence has been accumulated suggesting that Citrus fruits and their juices might have a role in preventing many diseases including cancer. Objective: To summarize the numerous evidences on the potential of Citrus juices and their extracts as anticancer agents. Data sources: A systematic review of articles written in English using MEDLINE (1946-present), EMBASE (1974-present) and Web of Sciences (1970-present) was performed independently by two reviewers. Search terms included Citrus, Citrus aurantifolia, Citrus sinensis, Citrus paradisi, Citrus fruits, Citrus fruits extract, cancer, neoplasm, neoplasia, tumor, metastasis, carcinogenesis, proliferation. The last search was performed on March 16th, 2017. Study selection: Study selection and systematic review were carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Prior to the beginning of the review, Authors defined a checklist for inclusion criteria, thus including articles which meet the following: (i) published on peer-reviewed scientific journals; (ii) Citrus juice used alone; (iii) extracts derived from Citrus juice; (iii) for preclinical studies, an exposure time to Citrus juices and their extracts more than 24 h. Reviews, meta-analyses, conference abstracts and book chapters were excluded. Data extraction: Three reviewers independently performed the extraction of articles. Data synthesis: 22 papers met our inclusion criteria and were eligible for inclusion in the final review. According to the kind of study, the selected ones were further divided in preclinical (n = 20) and observational (n = 2) studies. Conclusion: The studies discussed in this review strongly corroborate the role of Citrus juices and their derivatives as potential resource against cancer.

  3. Taking Journal Clubs off Autopilot: A Case Study of Teaching Literature Evaluation Skills to Preclinical MD/PhD Students.

    PubMed

    Currier, Rebecca L; Schneider, Marguerite Reid; Heubi, James E

    2013-12-01

    Researchers designed learner-directed journal clubs to develop literature evaluation skills in preclinical students. Sessions balanced student-led discussion with structured objectives and faculty support. During the pilot with preclinical MD/PhD students, self-rated mastery improved over all 17 measured objectives. Six exercises have since been incorporated into the full medical school curriculum.

  4. Engineering a biomimetic three-dimensional nanostructured bone model for breast cancer bone metastasis study.

    PubMed

    Zhu, Wei; Wang, Mian; Fu, Yebo; Castro, Nathan J; Fu, Sidney W; Zhang, Lijie Grace

    2015-03-01

    Traditional breast cancer (BrCa) bone metastasis models contain many limitations with regards to controllability, reproducibility and flexibility of design. In this study, a novel biomimetic bone microenvironment was created by integrating hydroxyapatite (HA) and native bioactive factors deposited by osteogenic induction of human bone marrow mesenchymal stem cells (MSCs) within a cytocompatible chitosan hydrogel. It was found that a 10% nanocrystalline HA (nHA) chitosan scaffold exhibited the highest BrCa adhesion and proliferation when compared to chitosan scaffolds with 20% nHA, 10% and 20% microcrystalline HA as well as amorphous HA. This 3-D tunable bone scaffold can provide a biologically relevant environment, increase cell-cell and cell-matrix interactions as found in native bone, and retain the behavior of BrCa cells with different metastasis potential (i.e. highly metastatic MDA-MB-231, less metastatic MCF-7 and transfected MDA-MB-231). The co-culture of MSCs and MDA-MB-231 in this bone model illustrated that MSCs have the capacity to upregulate the expression of the well-known metastasis-associated gene metadherin within BrCa cells. In summary, this study illustrates the ability of our 3-D bone model to create a biomimetic environment conducive to recapitulating the behavior of metastatic BrCa cells, making it a promising tool for in vitro BrCa cell bone metastasis study and for the discovery of potential therapeutics.

  5. [Preclinical study of immunocorrection action of the sum of active substances of Coluria geoides (Pall.) Ledeb. (Rosaceae)].

    PubMed

    Dutova, S V; Karpova, M R; Myadelets, M A; Myasnaya, N V; Sherstoboev, E Yu

    2015-01-01

    A preclinical study of the immunocorrection action of the sum of active substances isolated from ethereal-oil plants Coluria geoides (Pall.) Ledeb. (Rosaceae family) with respect to experimental immunodeficiency showed that preparations relieve symptoms of immunodeficiency caused by the administration of cyclophosphan: suppressed synthesis of anti-erythrocyte antibodies (agglutinine) and proliferative processes in the spleen. Under the influence of C. geoides preparations, the absolute numbers of cariocytes and antibody forming cells in spleen significantly increased (compared to the group of animals with experimental immunodeficiency) and in some cases reached the background level. The drugs studied produced a more pronounced stimulating effect on the synthesis of specific immunoglobulins and proliferation of antibody forming cells of spleen as compared to the effect of Echinacea tincture. Preparation C-2 (extract from underground organs and grass of C. geoides obtained by percolation method with 70% ethanol) is most promising for in-depth research and the development of new effective drugs with immunocorrecting properties.

  6. [An experimental study of bioglass implants in bone].

    PubMed

    Courpied, J P; Deplus, P; Barthas, J; Forest, M; Carlioz, A; Vacher-Lavenu, M C; Crouzette, J; Fournier, P; Baufume, M

    1982-06-01

    The tolerance and response of bone to bioglass have been studied using implants of various chemical constitution in animals.Glass discs were inserted between the inner and outer tables of the skull in 32 rabbits and small glass stick were implanted in the medullary cavity of long bones in 6 dogs. The results were analysed between 6 and 18 months later. High resolution radiographs and histopathological examination were performed.Some glass behaves like an inert material but other specimens are biodegradable and induce a satisfactory bone response in adjacent bone. Any new bone formation does not follow the classical stages of connective tissue, cartilage and woven bone. Bioglass is more suitable for bone than many other materials now in use and further applications in orthopaedic surgery may be considered.

  7. [An experimental study of bioglass implants in bone (author's transl)].

    PubMed

    Courpied, J P; Deplus, P; Barthas, J; Forest, M; Carlioz, A; Vacher-Lavenu, M C; Crouzette, J; Fournier, P; Baufume, M

    1982-01-01

    The tolerance and response of bone to bioglass have been studied using implants of various chemical constitution in animals. Glass discs were inserted between the inner and outer tables of the skull in 32 rabbits and small glass stick were implanted in the medullary cavity of long bones in 6 dogs. The results were analysed between 6 and 18 months later. High resolution radiographs and histopathological examination were performed. Some glass behaves like an inert material but other specimens are biodegradable and induce a satisfactory bone response in adjacent bone. Any new bone formation does not follow the classical stages of connective tissue, cartilage and woven bone. Bioglass is more suitable for bone than many other materials now in use and further applications in orthopaedic surgery may be considered.

  8. [Retrospective study on CT findings on the sternal bone after bone marrow aspiration procedure in hematological patients].

    PubMed

    Fujita, Hiroshi; Nishimura, Shigeko; Oyama, Kazuyuki

    2009-12-01

    We retrospectively studied the CT findings of sternal bone in 129 patients with hematological diseases who underwent bone marrow aspiration in Tokyo Metropolitan Bokutoh Hospital between August 2005 and July 2007. Sternal findings demonstrated sternal foramen (3 cases), incomplete fracture (1 case) and irregularity and decreased bone density of the visceral cortical bone (first intercostal space: 66 cases, third intercostal space: 3 cases). Irregularity and decreased bone density of the visceral cortical bone were significantly related to findings of decreased bone density in the third lumbar spine, indicating osteoporosis. These findings suggest that sternal bones demonstrated various bone diseases such as sternal foramen, fracture and osteoporosis, and that bone marrow aspiration from sternal bones might not be as safe as previously thought.

  9. Material model of pelvic bone based on modal analysis: a study on the composite bone.

    PubMed

    Henyš, Petr; Čapek, Lukáš

    2017-02-01

    Digital models based on finite element (FE) analysis are widely used in orthopaedics to predict the stress or strain in the bone due to bone-implant interaction. The usability of the model depends strongly on the bone material description. The material model that is most commonly used is based on a constant Young's modulus or on the apparent density of bone obtained from computer tomography (CT) data. The Young's modulus of bone is described in many experimental works with large variations in the results. The concept of measuring and validating the material model of the pelvic bone based on modal analysis is introduced in this pilot study. The modal frequencies, damping, and shapes of the composite bone were measured precisely by an impact hammer at 239 points. An FE model was built using the data pertaining to the geometry and apparent density obtained from the CT of the composite bone. The isotropic homogeneous Young's modulus and Poisson's ratio of the cortical and trabecular bone were estimated from the optimisation procedure including Gaussian statistical properties. The performance of the updated model was investigated through the sensitivity analysis of the natural frequencies with respect to the material parameters. The maximal error between the numerical and experimental natural frequencies of the bone reached 1.74 % in the first modal shape. Finally, the optimised parameters were matched with the data sheets of the composite bone. The maximal difference between the calibrated material properties and that obtained from the data sheet was 34 %. The optimisation scheme of the FE model based on the modal analysis data provides extremely useful calibration of the FE models with the uncertainty bounds and without the influence of the boundary conditions.

  10. Are All Dentiform Teeth with Simulated Caries the Same? A Six-Year Retrospective Study in Preclinical Operative Dentistry.

    PubMed

    Delgado, Alex J; Walter, Ricardo; Behar-Horenstein, Linda S; Boushell, Lee W

    2015-11-01

    Dentiform teeth with simulated caries (DTSC), frequently used in preclinical courses, should show no variability in the amount of simulated caries from tooth to tooth. However, the level of caries variability among DTSC is currently unknown. The aim of this study was to assess the variation in simulated caries levels in one group of DTSC and determine whether variation among DTSC impacted the preclinical performance of dental students. In the study, 80 commercially available mandibular first molar DTSC with simulated mesio-occluso-distal caries were sectioned in coronal (n=40) and sagittal (n=40) planes where the caries depth/width was greatest. Section images were analyzed for variation in levels of simulated caries using image-processing software. Three years of practical performance data using DTSC were compared with three years of practical performance data using dentiform teeth without simulated caries, for a total of six years (students' performance on two exams, Practical 1 and Practical 2). The results showed that 70% of the coronally sectioned teeth had manufacturing defects that resulted in caries overextension at the dentino-enamel junctions (DEJs). Overextensions were found at the DEJ in 41.3% of the sagittally sectioned teeth. There was a statistically significant decrease in Practical 1 performance of the students who used DTSC as compared with students who used teeth without simulated caries (p=0.0001); there was no statistically significant difference on Practical 2 performance. Of the DTSC evaluated in this study, 56.6% contained manufacturing defects, and more than 80% were found to have excessive caries variation. Prediction of which DTSC will have caries overextension is not possible. Students preparing DTSC that contain caries overextension are therefore at increased risk of receiving undeserved negative summative assessment on practical examinations.

  11. NIH initiative to balance sex of animals in preclinical studies: generative questions to guide policy, implementation, and metrics

    PubMed Central

    2014-01-01

    In May of 2014, the NIH Director together with the Director of the Office of Research on Women’s Health announced plans to take a multi-dimensional approach to address the over reliance on male cells and animals in preclinical research. The NIH is engaging the scientific community in the development of policies to improve the sex balance in research. The present, past, and future presidents of the Organization for the Study of Sex Differences, in order to encourage thoughtful discussion among scientists, pose a series of questions to generate ideas in three areas: 1. research strategies, 2. educational strategies, and 3. strategies to monitor effectiveness of policies to improve the sex balance in research. By promoting discussion within the scientific community, a consensus will evolve that will move science forward in a productive and effective manner. PMID:25780556

  12. Cranberries and Cancer: An Update of Preclinical Studies Evaluating the Cancer Inhibitory Potential of Cranberry and Cranberry Derived Constituents

    PubMed Central

    Weh, Katherine M.; Clarke, Jennifer; Kresty, Laura A.

    2016-01-01

    Cranberries are rich in bioactive constituents reported to influence a variety of health benefits, ranging from improved immune function and decreased infections to reduced cardiovascular disease and more recently cancer inhibition. A review of cranberry research targeting cancer revealed positive effects of cranberries or cranberry derived constituents against 17 different cancers utilizing a variety of in vitro techniques, whereas in vivo studies supported the inhibitory action of cranberries toward cancers of the esophagus, stomach, colon, bladder, prostate, glioblastoma and lymphoma. Mechanisms of cranberry-linked cancer inhibition include cellular death induction via apoptosis, necrosis and autophagy; reduction of cellular proliferation; alterations in reactive oxygen species; and modification of cytokine and signal transduction pathways. Given the emerging positive preclinical effects of cranberries, future clinical directions targeting cancer or premalignancy in high risk cohorts should be considered. PMID:27548236

  13. Two years later: journals are not yet enforcing the ARRIVE guidelines on reporting standards for pre-clinical animal studies.

    PubMed

    Baker, David; Lidster, Katie; Sottomayor, Ana; Amor, Sandra

    2014-01-01

    There is growing concern that poor experimental design and lack of transparent reporting contribute to the frequent failure of pre-clinical animal studies to translate into treatments for human disease. In 2010, the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines were introduced to help improve reporting standards. They were published in PLOS Biology and endorsed by funding agencies and publishers and their journals, including PLOS, Nature research journals, and other top-tier journals. Yet our analysis of papers published in PLOS and Nature journals indicates that there has been very little improvement in reporting standards since then. This suggests that authors, referees, and editors generally are ignoring guidelines, and the editorial endorsement is yet to be effectively implemented.

  14. Bioengineered Temporomandibular Joint Disk Implants: Study Protocol for a Two-Phase Exploratory Randomized Preclinical Pilot Trial in 18 Black Merino Sheep (TEMPOJIMS)

    PubMed Central

    Monje, Florencio Gil; González-García, Raúl; Little, Christopher B; Mónico, Lisete; Pinho, Mário; Santos, Fábio Abade; Carrapiço, Belmira; Gonçalves, Sandra Cavaco; Morouço, Pedro; Alves, Nuno; Moura, Carla; Wang, Yadong; Jeffries, Eric; Gao, Jin; Sousa, Rita; Neto, Lia Lucas; Caldeira, Daniel; Salvado, Francisco

    2017-01-01

    Background Preclinical trials are essential to test efficacious options to substitute the temporomandibular joint (TMJ) disk. The contemporary absence of an ideal treatment for patients with severe TMJ disorders can be related to difficulties concerning the appropriate study design to conduct preclinical trials in the TMJ field. These difficulties can be associated with the use of heterogeneous animal models, the use of the contralateral TMJ as control, the absence of rigorous randomized controlled preclinical trials with blinded outcomes assessors, and difficulties involving multidisciplinary teams. Objective This study aims to develop a new, reproducible, and effective study design for preclinical research in the TMJ domain, obtaining rigorous data related to (1) identify the impact of bilateral discectomy in black Merino sheep, (2) identify the impact of bilateral discopexy in black Merino sheep, and (3) identify the impact of three different bioengineering TMJ discs in black Merino sheep. Methods A two-phase exploratory randomized controlled preclinical trial with blinded outcomes is proposed. In the first phase, nine sheep are randomized into three different surgical bilateral procedures: bilateral discectomy, bilateral discopexy, and sham surgery. In the second phase, nine sheep are randomized to bilaterally test three different TMJ bioengineering disk implants. The primary outcome is the histological gradation of TMJ. Secondary outcomes are imaging changes, absolute masticatory time, ruminant time per cycle, ruminant kinetics, ruminant area, and sheep weight. Results Previous preclinical studies in this field have used the contralateral unoperated side as a control, different animal models ranging from mice to a canine model, with nonrandomized, nonblinded and uncontrolled study designs and limited outcomes measures. The main goal of this exploratory preclinical protocol is to set a new standard for future preclinical trials in oromaxillofacial surgery

  15. Topography of Acoustical Properties of Long Bones: From Biomechanical Studies to Bone Health Assessment

    PubMed Central

    Tatarinov, Alexey; Sarvazyan, Armen

    2010-01-01

    The article presents a retrospective view on the assessment of long bones condition using topographical patterns of the acoustic properties. The application of ultrasonic point-contact transducers with exponential waveguides on a short acoustic base for detailed measurements in human long bones by the surface transmission was initiated during the 1980s in Latvia. The guided wave velocity was mapped on the surface of the long bones and the topographical patterns reflected the biomechanical peculiarities. Axial velocity profiles obtained in vivo by measurements along the medial surface of tibia varied due to aging, hypokinesia, and physical training. The method has been advanced at Artann Laboratories (West Trenton, NJ) by the introduction of multifrequency data acquisition and axial scanning. The model studies carried out on synthetic phantoms and in bone specimens confirmed the potential to evaluate separately changes of the bone material properties and of the cortical thickness by multifrequency acoustic measurements at the 0.1 to 1 MHz band. The bone ultrasonic scanner (BUSS) is an axial mode ultrasonometer developed to depict the acoustic profile of bone that will detect the onset of bone atrophy as a spatial process. Clinical trials demonstrated a high sensitivity of BUSS to osteoporosis and the capability to assess early stage of osteopenia. PMID:18599416

  16. Topography of acoustical properties of long bones: from biomechanical studies to bone health assessment.

    PubMed

    Tatarinov, Alexey; Sarvazyan, Armen

    2008-01-01

    The article presents a retrospective view on the assessment of long bones condition using topographical patterns of the acoustic properties. The application of ultrasonic point-contact transducers with exponential waveguides on a short acoustic base for detailed measurements in human long bones by the surface transmission was initiated during the 1980s in Latvia. The guided wave velocity was mapped on the surface of the long bones and the topographical patterns reflected the biomechanical peculiarities. Axial velocity profiles obtained in vivo by measurements along the medial surface of tibia varied due to aging, hypokinesia, and physical training. The method has been advanced at Artann Laboratories (West Trenton, NJ) by the introduction of multifrequency data acquisition and axial scanning. The model studies carried out on synthetic phantoms and in bone specimens confirmed the potential to evaluate separately changes of the bone material properties and of the cortical thickness by multifrequency acoustic measurements at the 0.1 to 1 MHz band. The bone ultrasonic scanner (BUSS) is an axial mode ultrasonometer developed to depict the acoustic profile of bone that will detect the onset of bone atrophy as a spatial process. Clinical trials demonstrated a high sensitivity of BUSS to osteoporosis and the capability to assess early stage of osteopenia.

  17. Bone mass and bone metabolism markers during adolescence: The HELENA Study.

    PubMed

    Gracia-Marco, L; Vicente-Rodríguez, G; Valtueña, J; Rey-López, J P; Díaz Martínez, A E; Mesana, M I; Widhalm, K; Ruiz, J R; González-Gross, M; Castillo, M J; Moreno, L A

    2010-01-01

    The assessment of bone mineral content (BMC) and density (BMD) status in children and adolescents is important for health and the prevention of diseases. Bone metabolic activity could provide early information on bone mass development. Our aim was to describe bone mass and metabolism markers according to age and Tanner stage in adolescents. Spanish adolescents (n = 345; 168 males and 177 females) aged 12.5-17.5 years participated in this cross-sectional study. Body composition variables were measured by dual-energy X-ray absorptiometry. Serum osteocalcin (n = 101), aminoterminal propeptide of type I procollagen (n = 92) and β-isomerized C-telopeptides (β-CTX, n = 65) and urine samples (β-CTX; n = 237) were analyzed by electrochemiluminescence immunoassay. Analysis of covariance showed that females had higher values for BMC and BMD in most of the regions. Both males and females had a significant decrease in bone markers while sexual maturation increases (all p < 0.05). Males had an increased bone turnover compared to females (all p < 0.05, except for urine β-CTX in Tanner ≤IV). Our results support the evidence of dimorphic site-specific bone accretion between sexes and show an increased bone turnover in males, suggesting higher metabolic activity. Copyright © 2010 S. Karger AG, Basel.

  18. Permeability study of cancellous bone and its idealised structures.

    PubMed

    Syahrom, Ardiyansyah; Abdul Kadir, Mohammed Rafiq; Harun, Muhamad Nor; Öchsner, Andreas

    2015-01-01

    Artificial bone is a suitable alternative to autografts and allografts, however their use is still limited. Though there were numerous reports on their structural properties, permeability studies of artificial bones were comparably scarce. This study focused on the development of idealised, structured models of artificial cancellous bone and compared their permeability values with bone surface area and porosity. Cancellous bones from fresh bovine femur were extracted and cleaned following an established protocol. The samples were scanned using micro-computed tomography (μCT) and three-dimensional models of the cancellous bones were reconstructed for morphology study. Seven idealised and structured cancellous bone models were then developed and fabricated via rapid prototyping technique. A test-rig was developed and permeability tests were performed on the artificial and real cancellous bones. The results showed a linear correlation between the permeability and the porosity as well as the bone surface area. The plate-like idealised structure showed a similar value of permeability to the real cancellous bones.

  19. Preventing Electromagnetic Pulse Irradiation Damage on Testis Using Selenium-rich Cordyceps Fungi. A Preclinical Study in Young Male Mice.

    PubMed

    Miao, Xia; Wang, Yafeng; Lang, Haiyang; Lin, Yanyun; Guo, Qiyan; Yang, Mingjuan; Guo, Juan; Zhang, Yanjun; Zhang, Jie; Liu, Junye; Liu, Yaning; Zeng, Lihua; Guo, Guozhen

    2017-02-01

    Networked 21st century society, globalization, and communications technologies are paralleled by the rise of electromagnetic energy intensity in our environments and the growing pressure of the environtome on human biology and health. The latter is the entire complement of environmental factors, including the electromagnetic energy and the technologies that generate them, enacting on the digital citizen in the new century. Electromagnetic pulse (EMP) irradiation might have serious damaging effects not only on electronic equipment but also in the whole organism and reproductive health, through nonthermal effects and oxidative stress. We sought to determine whether EMP exposure (1) induces biological damage on reproductive health and (2) the extent to which selenium-rich Cordyceps fungi (daily coadministration) offer protection on the testicles and spermatozoa. In a preclinical randomized study, 3-week-old male BALB/c mice were repeatedly exposed to EMP (peak intensity 200 kV/m, pulse edge 3.5 ns, pulse width 15 ns, 0.1 Hz, and 400 pulses/day) 5 days per week for four consecutive weeks, with or without coadministration of daily selenium-rich Cordyceps fungi (100 mg/kg). Testicular index and spermatozoa formation were measured at baseline and 1, 7, 14, 28, and 60 day time points after EMP exposure. The group without Cordyceps cotreatment displayed decreased spermatozoa formation, shrunk seminiferous tubule diameters, and diminished antioxidative capacity at 28 and 60 days after exposure (p < 0.05). The Cordyceps daily cotreatment alleviated the testicular damage by EMP exposure, increased spermatozoa formation, and reduced apoptotic spermatogenic cells. These observations warrant further preclinical and clinical studies as an innovative approach for potential protection against electromagnetic radiation in the current age of networked society and digital citizenship.

  20. Translational reciprocity: bridging the gap between preclinical studies and clinical treatment of stress effects on the adolescent brain.

    PubMed

    Neigh, G N; Ritschel, L A; Kilpela, L S; Harrell, C S; Bourke, C H

    2013-09-26

    The genetic, biological, and environmental backgrounds of an organism fundamentally influence the balance between risk and resilience to stress. Sex, age, and environment transact with responses to trauma in ways that can mitigate or exacerbate the likelihood that post-traumatic stress disorder will develop. Translational approaches to modeling affective disorders in animals will ultimately provide novel treatments and a better understanding of the neurobiological underpinnings behind these debilitating disorders. The extant literature on trauma/stress has focused predominately on limbic and cortical structures that innervate the hypothalamic-pituitary-adrenal axis and influence glucocorticoid-mediated negative feedback. It is through these neuroendocrine pathways that a self-perpetuating fear memory can propagate the long-term effects of early life trauma. Recent work incorporating translational approaches has provided novel pathways that can be influenced by early life stress, such as the glucocorticoid receptor chaperones, including FKBP51. Animal models of stress have differing effects on behavior and endocrine pathways; however, complete models replicating clinical characteristics of risk and resilience have not been rigorously studied. This review discusses a four-factor model that considers the importance of studying both risk and resilience in understanding the developmental response to trauma/stress. Consideration of the multifactorial nature of clinical populations in the design of preclinical models and the application of preclinical findings to clinical treatment approaches comprise the core of translational reciprocity, which is discussed in the context of the four-factor model. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Pre-Clinical Studies with D-Penicillamine as a Novel Pharmacological Strategy to Treat Alcoholism: Updated Evidences

    PubMed Central

    Orrico, Alejandro; Martí-Prats, Lucía; Cano-Cebrián, María J.; Granero, Luis; Polache, Ana; Zornoza, Teodoro

    2017-01-01

    Ethanol, as other drugs of abuse, is able to activate the ventral tegmental area dopamine (VTA-DA) neurons leading to positively motivational alcohol-seeking behavior and use, and, ultimately to ethanol addiction. In the last decades, the involvement of brain-derived acetaldehyde (ACD) in the ethanol actions in the mesolimbic pathway has been widely demonstrated. Consistent published results have provided a mechanistic support to the use of ACD inactivating agents to block the motivational and reinforcing properties of ethanol. Hence, in the last years, several pre-clinical studies have been performed in order to analyze the effects of the sequestering ACD agents in the prevention of ethanol relapse-like drinking behavior as well as in chronic alcohol consumption. In this sense, one of the most explored interventions has been the administration of D-Penicillamine (DP). These pre-clinical studies, that we critically summarize in this article, are considered a critical step for the potential development of a novel pharmacotherapeutic strategy for alcohol addiction treatment that could improve the outcomes of current ones. Thus, on one hand, several experimental findings provide the rationale for using DP as a novel therapeutic intervention alone and/or in combination to prevent relapse into alcohol seeking and consumption. On the other hand, its effectiveness in reducing voluntary ethanol consumption in long-term experienced animals still remains unclear. Finally, this drug offers the additional advantage that has already been approved for use in humans, hence it could be easily implemented as a new therapeutic intervention for relapse prevention in alcoholism. PMID:28326026

  2. Pre-Clinical Studies with D-Penicillamine as a Novel Pharmacological Strategy to Treat Alcoholism: Updated Evidences.

    PubMed

    Orrico, Alejandro; Martí-Prats, Lucía; Cano-Cebrián, María J; Granero, Luis; Polache, Ana; Zornoza, Teodoro

    2017-01-01

    Ethanol, as other drugs of abuse, is able to activate the ventral tegmental area dopamine (VTA-DA) neurons leading to positively motivational alcohol-seeking behavior and use, and, ultimately to ethanol addiction. In the last decades, the involvement of brain-derived acetaldehyde (ACD) in the ethanol actions in the mesolimbic pathway has been widely demonstrated. Consistent published results have provided a mechanistic support to the use of ACD inactivating agents to block the motivational and reinforcing properties of ethanol. Hence, in the last years, several pre-clinical studies have been performed in order to analyze the effects of the sequestering ACD agents in the prevention of ethanol relapse-like drinking behavior as well as in chronic alcohol consumption. In this sense, one of the most explored interventions has been the administration of D-Penicillamine (DP). These pre-clinical studies, that we critically summarize in this article, are considered a critical step for the potential development of a novel pharmacotherapeutic strategy for alcohol addiction treatment that could improve the outcomes of current ones. Thus, on one hand, several experimental findings provide the rationale for using DP as a novel therapeutic intervention alone and/or in combination to prevent relapse into alcohol seeking and consumption. On the other hand, its effectiveness in reducing voluntary ethanol consumption in long-term experienced animals still remains unclear. Finally, this drug offers the additional advantage that has already been approved for use in humans, hence it could be easily implemented as a new therapeutic intervention for relapse prevention in alcoholism.

  3. The zebrafish infraorbital bones: a descriptive study.

    PubMed

    Chang, Carolyn; Franz-Odendaal, Tamara Anne

    2014-02-01

    The infraorbital (IO) bone series, a component of the circumorbital series, makes up five of the eight dermal bones found in the orbital region of the zebrafish skull. Ossifying in a set sequence, the IOs are closely associated with the cranial lateral line system as they house neuromast sensory receptors in bony canals. We conducted a detailed analysis of the condensation to mineralization phases of development of these bones. Our analyses involved both bone and osteoblast staining of zebrafish at 20 different time points. IO bone condensations are shaped as templates for the final bone shape, and they mineralize at one or more centers of ossification. Initially, mineralization is closely associated with the lateral line canals and/or foramen, and the onset of mineralization is temporally variable. Canal wall mineralization is a process that continues into adulthood and completely mineralized canal roofs were not found. Our comprehensive growth series detailing the ossification of each IO bone provides important insight into the growth and development of this series of neural crest-derived flat bones in the zebrafish craniofacial skeleton.

  4. Is Science the Only Driver in Species Selection? An Internal Study to Evaluate Compound Requirements in the Minipig Compared to the Dog in Preclinical Studies.

    PubMed

    Schaefer, Kai; Rensing, Susanne; Hillen, Heinz; Burkhardt, John E; Germann, Paul-Georg

    2016-04-01

    Dogs have been often chosen as a nonrodent species for preclinical development of small molecule drugs mainly due to availability and relative ease of handling. Recently, focus has increased on the minipig as a potential alternative to the dog, based on either scientific rationale or public opinion concerns. There are, however, other factors influencing nonrodent choices, in particular drug amount and synthesis time, which differ between species and therefore may impact the milestones of a drug development program. To assess the magnitude of compound need, a retrospective internal survey was conducted on drug amounts used in dog studies which were translated into the requirements for minipigs. Compound need approximately doubles if minipigs are used. Costs of compound are accordingly higher, and synthesis times are slightly increased. In our company, the differences were not considered significant enough to preclude the use of minipigs if the later preclinical program might benefit from improved human risk prediction.

  5. Two-Dimensional High Definition Versus Three-Dimensional Endoscopy in Endonasal Skull Base Surgery: A Comparative Preclinical Study.

    PubMed

    Rampinelli, Vittorio; Doglietto, Francesco; Mattavelli, Davide; Qiu, Jimmy; Raffetti, Elena; Schreiber, Alberto; Villaret, Andrea Bolzoni; Kucharczyk, Walter; Donato, Francesco; Fontanella, Marco Maria; Nicolai, Piero

    2017-09-01

    Three-dimensional (3D) endoscopy has been recently introduced in endonasal skull base surgery. Only a relatively limited number of studies have compared it to 2-dimensional, high definition technology. The objective was to compare, in a preclinical setting for endonasal endoscopic surgery, the surgical maneuverability of 2-dimensional, high definition and 3D endoscopy. A group of 68 volunteers, novice and experienced surgeons, were asked to perform 2 tasks, namely simulating grasping and dissection surgical maneuvers, in a model of the nasal cavities. Time to complete the tasks was recorded. A questionnaire to investigate subjective feelings during tasks was filled by each participant. In 25 subjects, the surgeons' movements were continuously tracked by a magnetic-based neuronavigator coupled with dedicated software (ApproachViewer, part of GTx-UHN) and the recorded trajectories were analyzed by comparing jitter, sum of square differences, and funnel index. Total execution time was significantly lower with 3D technology (P < 0.05) in beginners and experts. Questionnaires showed that beginners preferred 3D endoscopy more frequently than experts. A minority (14%) of beginners experienced discomfort with 3D endoscopy. Analysis of jitter showed a trend toward increased effectiveness of surgical maneuvers with 3D endoscopy. Sum of square differences and funnel index analyses documented better values with 3D endoscopy in experts. In a preclinical setting for endonasal skull base surgery, 3D technology appears to confer an advantage in terms of time of execution and precision of surgical maneuvers. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Is lecture dead? A preliminary study of medical students' evaluation of teaching methods in the preclinical curriculum.

    PubMed

    Zinski, Anne; Blackwell, Kristina T C Panizzi Woodley; Belue, F Mike; Brooks, William S

    2017-09-22

    To investigate medical students' perceptions of lecture and non-lecture-based instructional methods and compare preferences for use and quantity of each during preclinical training. We administered a survey to first- and second-year undergraduate medical students at the University of Alabama School of Medicine in Birmingham, Alabama, USA aimed to evaluate preferred instructional methods.  Using a cross-sectional study design, Likert scale ratings and student rankings were used to determine preferences among lecture, laboratory, team-based learning, simulation, small group case-based learning, large group case-based learning, patient presentation, and peer teaching. We calculated mean ratings for each instructional method and used chi-square tests to compare proportions of first- and second-year cohorts who ranked each in their top 5 preferred methods. Among participating students, lecture (M=3.6, SD=1.0), team based learning (M=4.2, SD=1.0), simulation (M=4.0, SD=1.0), small group case-based learning (M=3.8, SD=1.0), laboratory (M=3.6, SD=1.0), and patient presentation (M=3.8, SD=0.9) received higher scores than other instructional methods. Overall, second-year students ranked lecture lower (χ(2)(1, N=120) =16.33, p<0.0001) and patient presentation higher (χ(2)(1, N=120) =3.75, p=0.05) than first-year students. While clinically-oriented teaching methods were preferred by second-year medical students, lecture-based instruction was popular among first-year students. Results warrant further investigation to determine the ideal balance of didactic methods in undergraduate medical education, specifically curricula that employ patient-oriented instruction during the second preclinical year.

  7. Use of a collaborative tool to simplify the outsourcing of preclinical safety studies: an insight into the AstraZeneca-Charles River Laboratories strategic relationship.

    PubMed

    Martin, Frederic D C; Benjamin, Amanda; MacLean, Ruth; Hollinshead, David M; Landqvist, Claire

    2017-08-26

    In 2012, AstraZeneca entered into a strategic relationship with Charles River Laboratories whereby preclinical safety packages comprising safety pharmacology, toxicology, formulation analysis, in vivo ADME, bioanalysis and pharmacokinetics studies are outsourced. New processes were put in place to ensure seamless workflows with the aim of accelerating the delivery of new medicines to patients. Here, we describe in more detail the AstraZeneca preclinical safety outsourcing model and the way in which a collaborative tool has helped to translate the processes in AstraZeneca and Charles River Laboratories into simpler integrated workflows that are efficient and visible across the two companies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Fixation of tibial plateau fractures with synthetic bone graft versus natural bone graft: a comparison study.

    PubMed

    Ong, J C Y; Kennedy, M T; Mitra, A; Harty, J A

    2012-06-01

    The goal of this study was to determine differences in fracture stability and functional outcome between synthetic bone graft and natural bone graft with internal fixation of tibia plateau metaphyseal defects. Hydroxyapatite calcium carbonate synthetic bone graft was utilised in 14 patients (six males and eight females). Allograft/autograft were utilised in the remaining 10 patients (six males and four females). All the 24 patients had clinical, radiological and subjective functional score assessments. There was no significant statistical difference between the groups for post-operative articular reduction, long-term subsidence, and WOMAC scores. The degree of subsidence was not related to age or fracture severity. Maintenance of knee flexion was found to be better in the allograft/autograft group (p = 0.048) when compared between the groups. Multivariate analysis compared graft type, fracture severity, post-operative reduction, subsidence rate, range of movement and WOMAC score. The only finding was a statistical significant association with the graft type related to the 6-month range of movement figures. Use of autologous or allogenic bone graft allows better recovery of long-term flexion, possibly due to reduced inflammatory response compared with synthetic bone composites. However, all other parameters, such as maintenance of joint reduction and subjective outcome measures were comparable with the use of hydroxyapatite calcium carbonate bone graft. This study shows that synthetic bone graft may be a suitable alternative in fixation of unstable tibia plateau fractures, avoiding risk of disease transmission with allograft and donor site morbidity associated with autograft.

  9. Local and systemic toxicity of intravitreal melphalan for vitreous seeding in retinoblastoma: a preclinical and clinical study.

    PubMed

    Francis, Jasmine H; Schaiquevich, Paula; Buitrago, Emiliano; Del Sole, María José; Zapata, Gustavo; Croxatto, J Oscar; Marr, Brian P; Brodie, Scott E; Berra, Alejandro; Chantada, Guillermo L; Abramson, David H

    2014-09-01

    Intravitreal melphalan is emerging as an effective treatment for refractory vitreous seeds in retinoblastoma, but there is limited understanding regarding its toxicity. This study evaluates the retinal and systemic toxicity of intravitreal melphalan in retinoblastoma patients, with preclinical validation in a rabbit model. Clinical and preclinical, prospective, cohort study. In the clinical study, 16 patient eyes received 107 intravitreal injections of 30 μg melphalan given weekly, a median of 6.5 times (range, 5-8). In the animal study, 12 New Zealand/Dutch Belt pigmented rabbits were given 3 weekly injections of 15 μg of intravitreal melphalan or vehicle to the right eye. Electroretinogram (ERG) responses were recorded in both humans and rabbits. For the clinical study, ERG responses were recorded at baseline, immediately before each injection, and at each follow-up visit; 82 of these studies were deemed evaluable. Median follow-up time was 5.2 months (range, 1-11). Complete blood counts (CBCs) were obtained on the day of injection at 46 patient visits. In the animal study, ERG responses were obtained along with fluorescein angiography, CBCs, and melphalan plasma concentration. After humane killing, the histopathology of the eyes was evaluated. For the clinical study, we measured peak-to-peak ERG amplitudes in response to 30-Hz photopic flicker stimulation with comparisons between ERG studies before and after intravitreal melphalan. For the animal study, we collected ERG parameters before and after intravitreal melphalan injections with histopathologic findings. By linear regression analysis, over the course of weekly intravitreal injections in retinoblastoma patients, for every additional injection, the ERG amplitude decreased by approximately 5.8 μV. The ERG remained stable once the treatment course was completed. In retinoblastoma patients, there were no grade 3 or 4 hematologic events. One week after the second injection in rabbits, the a- and b

  10. Denosumab for bone diseases: translating bone biology into targeted therapy.

    PubMed

    Tsourdi, Elena; Rachner, Tilman D; Rauner, Martina; Hamann, Christine; Hofbauer, Lorenz C

    2011-12-01

    Signalling of receptor activator of nuclear factor-κB (RANK) ligand (RANKL) through RANK is a critical pathway to regulate the differentiation and activity of osteoclasts and, hence, a master regulator of bone resorption. Increased RANKL activity has been demonstrated in diseases characterised by excessive bone loss such as osteoporosis, rheumatoid arthritis and osteolytic bone metastases. The development and approval of denosumab, a fully MAB against RANKL, has heralded a new era in the treatment of bone diseases by providing a potent, targeted and reversible inhibitor of bone resorption. This article summarises the molecular and cellular biology of the RANKL/RANK system and critically reviews preclinical and clinical studies that have established denosumab as a promising novel therapy for metabolic and malignant bone diseases. We will discuss the potential indications for denosumab along with a critical review of safety and analyse its potential within the concert of established therapies.

  11. Effect of leukocyte- and platelet-rich fibrin (L-PRF) on bone regeneration: a study in rabbits.

    PubMed

    Knapen, Michel; Gheldof, Damien; Drion, Pierre; Layrolle, Pierre; Rompen, Eric; Lambert, France

    2015-01-01

    The positive effect of leukocyte- and platelet-rich fibrin (L-PRF) on osteogenesis has been widely described in vitro. However, clinical and preclinical studies are very little and controversial in demonstrating a significant beneficial effect of L-PRF in bone regeneration. The goal of the present study was to compare the potential effect of L-PRF in a standardized model. A total of 72 hemispheres were implanted on the calvaria of 18 rabbits and filled with three different space fillers: L-PRF, bovine hydroxyapatite (BHA), BHA + L-PRF, and an empty hemisphere was used as control. Six rabbits were sacrificed at three distinct time points: 1 week, 5 weeks, and 12 weeks. Histological and histomorphometrical analyses were carried out. At the early phase of bone regeneration (1 week), from a descriptive analysis, a higher proportion of connective tissue colonized the regeneration chamber in the two groups containing BHA particles. Nevertheless, no statistical differences were found within the four groups in terms of bone quantity and quality at each timepoint (p = .3623). According to the present study, L-PRF does not seem to provide any additional effect on the kinetics, quality, and quantity of bone in the present model of guided bone regeneration. © 2013 Wiley Periodicals, Inc.

  12. Concise Review: Review and Perspective of Cell Dosage and Routes of Administration From Preclinical and Clinical Studies of Stem Cell Therapy for Heart Disease

    PubMed Central

    Golpanian, Samuel; Schulman, Ivonne H.; Ebert, Ray F.; Heldman, Alan W.; DiFede, Darcy L.; Yang, Phillip C.; Wu, Joseph C.; Bolli, Roberto; Perin, Emerson C.; Simari, Robert D.; Wolf, Ariel; Hare, Joshua M.

    2016-01-01

    An important stage in the development of any new therapeutic agent is establishment of the optimal dosage and route of administration. This can be particularly challenging when the treatment is a biologic agent that might exert its therapeutic effects via complex or poorly understood mechanisms. Multiple preclinical and clinical studies have shown paradoxical results, with inconsistent findings regarding the relationship between the cell dose and clinical benefit. Such phenomena can, at least in part, be attributed to variations in cell dosing or concentration and the route of administration (ROA). Although clinical trials of cell-based therapy for cardiovascular disease began more than a decade ago, specification of the optimal dosage and ROA has not been established. The present review summarizes what has been learned regarding the optimal cell dosage and ROA from preclinical and clinical studies of stem cell therapy for heart disease and offers a perspective on future directions. Significance Preclinical and clinical studies on cell-based therapy for cardiovascular disease have shown inconsistent results, in part because of variations in study-specific dosages and/or routes of administration (ROA). Future preclinical studies and smaller clinical trials implementing cell-dose and ROA comparisons are warranted before proceeding to pivotal trials. PMID:26683870

  13. Preclinical Diastolic Dysfunction

    PubMed Central

    Wan, Siu-Hin; Vogel, Mark W.; Chen, Horng H

    2014-01-01

    Preclinical Diastolic Dysfunction (PDD) has been broadly defined as subjects with left ventricular diastolic dysfunction, without the diagnosis of congestive heart failure (HF), and with normal systolic function. PDD is an entity which remains poorly understood, yet has definite clinical significance. Although few original studies have focused on PDD, it has been shown that PDD is prevalent, and that there is a clear progression from PDD to symptomatic heart failure including dyspnea, edema, and fatigue. In diabetic patients and patients with coronary artery disease or hypertension, it has been shown that patients with PDD have a significantly higher risk of progression to heart failure and death compared to patients without PDD. Because of these findings and the increasing prevalence of the heart failure epidemic, it is clear that an understanding of PDD is essential to decreasing patients’ morbidity and mortality. This review will focus on what is known concerning preclinical diastolic dysfunction, including definitions, staging, epidemiology, pathophysiology, and the natural history of the disease. In addition, given the paucity of trials focused on PDD treatment, studies targeting risk factors associated with the development of PDD and therapeutic trials for heart failure with preserved ejection fraction will be reviewed. PMID:24291270

  14. X-Ray Exam: Bone Age Study (For Parents)

    MedlinePlus

    ... Habits for TV, Video Games, and the Internet X-Ray Exam: Bone Age Study KidsHealth > For Parents > X-Ray Exam: Bone Age Study Print A A A ... system. It's usually done by taking a single X-ray of the left wrist, hand, and fingers. It ...

  15. Role of phytochemicals in the prevention of menopausal bone loss: evidence from in vitro and in vivo, human interventional and pharma-cokinetic studies.

    PubMed

    Sharan, Kunal; Siddiqui, Jawed A; Swarnkar, Gaurav; Maurya, Rakesh; Chattopadhyay, Naibedya

    2009-01-01

    Substantial body of data generated from cultured bone cells and rat models of osteoporosis supports a significant bone-conserving effect of phytochemicals. Flavonoids including isoflavones, stilbenes and lignans with variable efficacy have shown promising therapeutic application in osteoporosis. Majority of the phytochemicals assessed for their effects on bone cells revealed multiple beneficial actions such as promoting osteoblast functions, and inhibiting osteoclast and adipocyte functions. A variety of molecular targets mediate multiple effects of phytochemicals in bone cells. In vivo, quite a few phytochemicals have been found to afford bone-sparing effect and in some cases even bone restoring effect. However, important pharmacokinetic and bioavailaibility studies associated with these phytochemicals are mostly lacking. As a result, translating these findings to the clinic has been challenging, and so far only a few clinical studies have attempted to evaluate the effect of phytochemicals in menopausal osteoporosis. Clinical studies so far performed are with dietary supplements rather than pure phytochemicals. Clinical trials with pure molecules necessitate preclinical regulatory and safety studies that are not available with the phytochemicals except ipriflavone with bone-conserving properties. Ipriflavone is the only marketed anti-osteoporosis agent that was obtained following a lead from natural substance. As phytochemicals have multiple beneficial influences on bone cells, making analogues of the most potent molecule for developing synthetic series with rational drug design approach could pay rich dividends in menopausal osteoporosis therapy.

  16. Gut microbiota-bone axis.

    PubMed

    Villa, Christopher R; Ward, Wendy E; Comelli, Elena M

    2017-05-24

    The gut microbiota (GM) is an important regulator of body homeostasis, including intestinal and extra-intestinal effects. This review focuses on the GM-bone axis, which we define as the effect of the gut-associated microbial community or the molecules they synthesize, on bone health. While research in this field is limited, findings from preclinical studies support that gut microbes positively impact bone mineral density and strength parameters. Moreover, administration of beneficial bacteria (probiotics) in preclinical models has demonstrated higher bone mineralization and greater bone strength. The preferential bacterial genus that has shown these beneficial effects in bone is Lactobacillus and thus lactobacilli are among the best candidates for future clinical intervention trials. However, their effectiveness is dependent on stage of development, as early life constitutes an important time for impacting bone health, perhaps via modulation of the GM. In addition, sex-specific difference also impacts the efficacy of the probiotics. Although auspicious, many questions regarding the GM-bone axis require consideration of potential mechanisms; sex-specific efficacy; effective dose of probiotics; and timing and duration of treatment.

  17. Overcoming immunosuppression in bone metastases.

    PubMed

    Reinstein, Zachary Z; Pamarthy, Sahithi; Sagar, Vinay; Costa, Ricardo; Abdulkadir, Sarki A; Giles, Francis J; Carneiro, Benedito A

    2017-09-01

    Bone metastases are present in up to 70% of advanced prostate and breast cancers and occur at significant rates in a variety of other cancers. Bone metastases can be associated with significant morbidity. The establishment of bone metastasis activates several immunosuppressive mechanisms. Hence, understanding the tumor-bone microenvironment is crucial to inform the development of novel therapies. This review describes the current standard of care for patients with bone metastatic disease and novel treatment options targeting the microenvironment. Treatments reviewed include immunotherapies, cryoablation, and targeted therapies. Combinatorial treatment strategies including targeted therapies and immunotherapies show promise in pre-clinical and clinical studies to overcome the suppressive environment and improve treatment of bone metastases. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Anthropometric models of bone mineral content and areal bone mineral density based on the bone mineral density in childhood study

    PubMed Central

    Gilsanz, V.; Kalkwarf, H. J.; Lappe, J. M.; Oberfield, S.; Shepherd, J. A.; Winer, K. K.; Zemel, B. S.; Hangartner, T. N.

    2016-01-01

    Summary New models describing anthropometrically adjusted normal values of bone mineral density and content in children have been created for the various measurement sites. The inclusion of multiple explanatory variables in the models provides the opportunity to calculate Z-scores that are adjusted with respect to the relevant anthropometric parameters. Introduction Previous descriptions of children’s bone mineral measurements by age have focused on segmenting diverse populations by race and sex without adjusting for anthropometric variables or have included the effects of a single anthropometric variable. Methods We applied multivariate semi-metric smoothing to the various pediatric bone-measurement sites using data from the Bone Mineral Density in Childhood Study to evaluate which of sex, race, age, height, weight, percent body fat, and sexual maturity explain variations in the population’s bone mineral values. By balancing high adjusted R2 values with clinical needs, two models are examined. Results At the spine, whole body, whole body sub head, total hip, hip neck, and forearm sites, models were created using sex, race, age, height, and weight as well as an additional set of models containing these anthropometric variables and percent body fat. For bone mineral density, weight is more important than percent body fat, which is more important than height. For bone mineral content, the order varied by site with body fat being the weakest component. Including more anthropometrics in the model reduces the overlap of the critical groups, identified as those individuals with a Z-score below −2, from the standard sex, race, and age model. Conclusions If body fat is not available, the simpler model including height and weight should be used. The inclusion of multiple explanatory variables in the models provides the opportunity to calculate Z-scores that are adjusted with respect to the relevant anthropometric parameters. PMID:25311106

  19. EXPERIMENTAL STUDIES ON HETEROPLASTIC BONE FORMATION

    PubMed Central

    Asami, Goichi; Dock, William

    1920-01-01

    1. Bone formation in the rabbit kidney with ligated vessels takes place (a) through the activity of young fibroblasts which accumulate to form a membrane-like structure; (b) subsequently by direct ossification of hyaline connective tissue in continuity with preformed bone; and (c) through erosion of lime placques by granulating tissue and laying down of lamellar bone by cells derived from fibroblasts. 2. Bone formation in the rabbit kidney begins not in direct contact with calcium deposits, but in the loose vascular connective tissue close under the transitional epithelium of the calices. 3. With autotransplanted ear cartilage of the rabbit there is an active new formation of cartilage in the connective tissue which surrounds the transplants, and the bone is formed by the fibroblasts from the perichondrium which erode and invade the calcified areas in this new cartilage. 4. The process of bone formation in the kidney is similar to that found in normal membranous ossification, while with the transplanted ear cartilage the process is identical with endochondral ossification. PMID:19868472

  20. COMPARATIVE STUDY OF BONE NEOFORMATION USING AUTOLOGOUS GRAFTING AND THREE REPLACEMENTS: BONE DEFECTS IN RATS

    PubMed Central

    Stein, Rodrigo Steffen; Silva, Jefferson Braga; Silva, Vinicius Duval da

    2015-01-01

    Objective: Compare the percentage of bone neoformation promoted by autologous bone grafting and three kinds of replacement materials with different characteristics in rats' femoral holes. Methods: Two holes measuring 5.4×2.7mm, were produced on each femur (right and left) of 14 isogenic Wistar rats. Each of the four defects produced was filled by autologous bone or by one of three tested materials-hydroxyapatite (HA), Genphos® (HA+ β-TCP) and GenMix® (a combined bovine bone graft). In the end of the 6-week (n = 6) and 12-week (n = 8) periods, the animals were sacrificed. The sections (stained with Picro-Sirius) were assessed by optical microscopy and specific software. Results: The groups with autologous bone were shown to be significantly superior to the others at both assessed times, showing a mean bone formation rate ± SD of 90.6 ± 10.8% in six weeks, and 98 ± 9.2% in 12 weeks (p > 0.0001 for both assessed times). In six weeks, the results for the other groups were the following: Genphos®, 46 ± 7.1%; HA, 43.1 ± 8.4%; and GenMix®, 57.3 ± 4.5%. In 12 weeks: Genphos®, 47.8 ± 11.1%; HA, 39.9 ± 5.4%; GenMix®, 59.7 ± 4.8%, significant (p = 0.007). Conclusions: In both assessed times, the three bone replacement materials tested in the study showed to be inferior to autologous bone graft for bone neoformation percentage. PMID:27022515

  1. Anti-tumor activity of calcitriol: pre-clinical and clinical studies.

    PubMed

    Trump, Donald L; Hershberger, Pamela A; Bernardi, Ronald J; Ahmed, Sharmilla; Muindi, Josephia; Fakih, Marwan; Yu, Wei-Dong; Johnson, Candace S

    2004-05-01

    1,25-Dihydroxycholecalciferol (calcitriol) is recognized widely for its effects on bone and mineral metabolism. Epidemiological data suggest that low Vitamin D levels may play a role in the genesis of prostate cancer and perhaps other tumors. Calcitriol is a potent anti-proliferative agent in a wide variety of malignant cell types. In prostate, breast, colorectal, head/neck and lung cancer as well as lymphoma, leukemia and myeloma model systems calcitriol has significant anti-tumor activity in vitro and in vivo. Calcitriol effects are associated with an increase in G0/G1 arrest, induction of apoptosis and differentiation, modulation of expression of growth factor receptors. Glucocorticoids potentiate the anti-tumor effect of calcitriol and decrease calcitriol-induced hypercalcemia. Calcitriol potentiates the antitumor effects of many cytotoxic agents and inhibits motility and invasiveness of tumor cells and formation of new blood vessels. Phase I and II trials of calcitriol either alone or in combination with carboplatin, taxanes or dexamethasone have been initiated in patients with androgen dependent and independent prostate cancer and advanced cancer. Data indicate that high-dose calcitriol is feasible on an intermittent schedule, no dose-limiting toxicity has been encountered and optimal dose and schedule are being delineated. Clinical responses have been seen with the combination of high dose calcitriol+dexamethasone in androgen independent prostate cancer (AIPC) and apparent potentiation of the antitumor effects of docetaxel have been seen in AIPC. These results demonstrate that high intermittent doses of calcitriol can be administered to patients without toxicity, that the MTD is yet to be determined and that calcitriol has potential as an anti-cancer agent.

  2. Molecular Genetic Studies of Bone Mechanical Strain and of Pedigrees with Very High Bone Density

    DTIC Science & Technology

    2009-11-01

    phenotype, we have used 2 approaches; single nucleotide polymorphism (SNP) analyses and gene expression changes. These 2 strategies have been...32 Dr. Subburaman Mohan 5 Molecular Genetic Studies of Bone Mechanical Strain Osteoporosis is a disease that is characterized by low bone...annual economic burden of osteoporosis is $20 billion and is expected to reach $62 billion by the year 2020 (1). These numbers exceed the cost of

  3. Preliminary fsLIBS study on bone tumors

    PubMed Central

    Gill, Ruby K.; Smith, Zachary J.; Panchal, Ripul R.; Bishop, John W.; Gandour-Edwards, Regina; Wachsmann-Hogiu, Sebastian

    2015-01-01

    The aim of this study is to evaluate the capability of femtosecond Laser Induced Breakdown Spectroscopy (fsLIBS) to discriminate between normal and cancerous bone, with implications to femtosecond laser surgery procedures. The main advantage of using femtosecond lasers for surgery is that the same laser that is being used to ablate can also be used for a feedback system to prevent ablation of certain tissues. For bone tumor removal, this technique has the potential to reduce the number of repeat surgeries that currently must be performed due to incomplete removal of the tumor mass. In this paper, we performed fsLIBS on primary bone tumor, secondary tumor in bone, and normal bone. These tissues were excised from consenting patients and processed through the UC Davis Cancer Center Biorepository. For comparison, each tumor sample had a matched normal bone sample. fsLIBS was performed to characterize the spectral signatures of each tissue type. A minimum of 20 spectra were acquired for each sample. We did not detect significant differences between the fsLIBS spectra of secondary bone tumors and their matched normal bone samples, likely due to the heterogeneous nature of secondary bone tumors, with normal and cancerous tissue intermingling. However, we did observe an increase in the fsLIBS magnesium peak intensity relative to the calcium peak intensity for the primary bone tumor samples compared to the normal bone samples. These results show the potential of using femtosecond lasers for both ablation and a real-time feedback control system for treatment of primary bone tumors. PMID:26713199

  4. A Sheep Model for Cancellous Bone Healing

    PubMed Central

    Malhotra, Angad; Pelletier, Matthew Henry; Yu, Yan; Christou, Chris; Walsh, William Robert

    2014-01-01

    Appropriate well-characterized bone defect animal models remain essential for preclinical research. This pilot study demonstrates a relevant animal model for cancellous bone defect healing. Three different defect diameters (8, 11, 14 mm) of fixed depth (25 mm) were compared in both skeletally immature (18-month-old) and aged sheep (5-year-old). In each animal, four defects were surgically created and placed in the cancellous bone of the medial distal femoral and proximal tibial epiphyses bilaterally. Animals were euthanized at 4 weeks post-operatively to assess early healing and any biological response. Defect sites were graded radiographically, and new bone formation quantified using μCT and histomorphometry. Fibrous tissue was found within the central region in most of the defects with woven bone normally forming near the periphery of the defect. Bone volume fraction [bone volume (BV)/TV] significantly decreased with an increasing defect diameter. Actual BV, however, increased with defect diameter. Bone ingrowth was lower for all defect diameters in the aged group. This pilot study proposes that the surgical creation of 11 mm diameter defects in the proximal tibial and distal femoral epiphyses of aged sheep is a suitable large animal model to study early healing of cancellous bone defects. The refined model allows for the placement of four separate bone defects per animal and encourages a reduction in animal numbers required for preclinical research. PMID:25593961

  5. Frequency Analyses Can Be Improved by a Modified t-test in Sample-based Preclinical Efficacy Studies.

    PubMed

    Halperin, Gideon; Klausner, Ziv

    2013-01-01

    Sample-based preclinical drug efficacy studies compare frequency (proportion) or incidences of successes within respective samples of test and control groups. The word success in principle refers to a protected (e.g., due to vaccination), recovered, or surviving animal, depending on the particular experiment. We introduce here a modified t-test for two independent groups, aimed at statistical analysis of the difference between frequencies of successes in sample based preclinical studies. The test is applicable whenever the study is based on repeating replicate experiments, as required by certain procedures such as validation. Such experiments are based on constant drug dose and performed under identical conditions and protocol. The proposed test combines the computational rules of t-test for two independent groups and analysis of variance. In the initial steps, incidences are transformed to proportions, and variance between proportions in samples of the j(th) group (s(p(j))(2)), is then transformed into theoretical weighted variance within the i(th) repetition (sample) of the j(th) group (s(i,j)(2)). The variance of proportions in samples of the size of the whole group (SE(j)(2)) is then calculated. The t-statistic is computed according to the rules of t-test for two independent groups. Significance is calculated using (N(1) - 1) + (N(2) - 1) degrees of freedom, where N(j) denotes the total number of animals in the j(th) group. The proposed model offers an important advantage over incidence or proportion distribution models, such as chi-square or normal approximation of binomial distribution, respectively, because it considers variance between replicate experiments. It moreover offers important flexibility by limiting the requirement for identical sample sizes only to samples within the control or test group. A difference between groups in sample sizes, number of samples, or both, preventing application of block designs or the standard formats of t-test, may still

  6. A clinicopathological study of giant cell tumor of small bones.

    PubMed

    Yanagisawa, Michiro; Okada, Kyoji; Tajino, Takahiro; Torigoe, Tomoaki; Kawai, Akira; Nishida, Jun

    2011-11-01

    Giant cell tumor (GCT) of the small bones (small-bone GCT) is usually rare and considered somewhat different from conventional GCT. The purpose of this study was to investigate and report the clinicopathological features of 11 cases with small-bone GCT. Patient information was obtained with the help of questionnaires. X-rays and paraffin blocks obtained from several institutions were clinically, radiographically, and histologically evaluated. Small-bone GCT was observed in younger patients compared to conventional GCT; 5 of the 11 (45%) patients were below 20 years of age, whereas the corresponding figure for all GCT patients is 16% in Japan. Excessive cortical bone expansion is a special feature. There were two cases of recurrence and one case of lung metastasis; the primary lesion was in the hand for all three cases. In contrast, no primary lesion of the foot recurred or metastasized. Varying degrees of positive p63 immunostaining were observed in all examined cases (n = 9) of small-bone GCT but were negative in case of giant cell reparative granuloma (GCRG) and solid variant of aneurysmal bone cyst (ABC). One case that demonstrated high-intensity positive staining had two episodes of recurrence. Small-bone GCT tends to develop in younger patients than does conventional GCT. Primary GCTs of the hand may be biologically more aggressive than those of the feet. The p63 immunostaining may be useful not only for differential diagnosis but also for prognostication of small-bone GCT.

  7. Gene Expression in Osteolysis: Review on the Identification of Altered Molecular Pathways in Preclinical and Clinical Studies

    PubMed Central

    Veronesi, Francesca; Tschon, Matilde; Fini, Milena

    2017-01-01

    Aseptic loosening (AL) due to osteolysis is the primary cause of joint prosthesis failure. Currently, a second surgery is still the only available treatment for AL, with its associated drawbacks. The present review aims at identifying genes whose expression is altered in osteolysis, and that could be the target of new pharmacological treatments, with the goal of replacing surgery. This review also aims at identifying the molecular pathways altered by different wear particles. We reviewed preclinical and clinical studies from 2010 to 2016, analyzing gene expression of tissues or cells affected by osteolysis. A total of 32 in vitro, 16 in vivo and six clinical studies were included. These studies revealed that genes belonging to both inflammation and osteoclastogenesis pathways are mainly involved in osteolysis. More precisely, an increase in genes encoding for the following factors were observed: Interleukins 6 and 1β (IL16 and β), Tumor Necrosis Factor α (TNFα), nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), Nuclear factor of activated T-cells, cytoplasmic 1 (NFATC1), Cathepsin K (CATK) and Tartrate-resistant acid phosphatase (TRAP). Titanium (Ti) and Polyethylene (PE) were the most studied particles, showing that Ti up-regulated inflammation and osteoclastogenesis related genes, while PE up-regulated primarily osteoclastogenesis related genes. PMID:28245614

  8. Preclinical study of using multiphoton microscopy to diagnose liver cancer and differentiate benign and malignant liver lesions

    NASA Astrophysics Data System (ADS)

    Yan, Jun; Zhuo, Shuangmu; Chen, Gang; Wu, Xiufeng; Zhou, Dong; Xie, Shusen; Jiang, Jiahao; Ying, Mingang; Jia, Fan; Chen, Jianxin; Zhou, Jian

    2012-02-01

    Recently, the miniaturized multiphoton microscopy (MPM) and multiphoton probe allow the clinical use of multiphoton endoscopy for diagnosing cancer via ``optical biopsy''. The purpose of this study was to establish MPM optical diagnostic features for liver cancer and evaluate the sensitivity, specificity, and accuracy of MPM optical diagnosis. Firstly, we performed a pilot study to establish the MPM diagnostic features by investigating 60 surgical specimens, and found that high-resolution MPM images clearly demonstrated apparent differences between benign and malignant liver lesions in terms of their tissue architecture and cell morphology. Cancer cells, characterized by irregular size and shape, enlarged nuclei, and increased nuclear-cytoplasmic ratio, were identified by MPM images, which were comparable to hematoxylin-eosin staining images. Secondly, we performed a blinded study to evaluate the sensitivity, specificity, and accuracy of MPM optical diagnosis by investigating another 164 specimens, and found that the sensitivity, specificity, and accuracy of MPM diagnosis was 96.32%, 96.43%, and 96.34%, respectively. In conclusion, it is feasible to use MPM to diagnose liver cancer and differentiate benign and malignant liver lesions. This preclinical study provides the groundwork for further using multiphoton endoscopy to perform real-time noninvasive ``optical biopsy'' for liver lesions in the near future.

  9. Engineering Endochondral Bone: In Vitro Studies

    PubMed Central

    Oliveira, Serafim M.; Amaral, Isabel F.; Barbosa, Mário A.

    2009-01-01

    Chitosan scaffolds have been shown to possess biological and mechanical properties suitable for tissue engineering and clinical applications. In the present work, chitosan sponges were evaluated regarding their ability to support cartilage cell proliferation and maturation, which are the first steps in endochondral bone formation. Chitosan sponges were seeded with chondrocytes isolated from chicken embryo sterna. Chondrocyte/chitosan constructs were cultured for 20 days, and treated with retinoic acid (RA) to induce chondrocyte maturation and matrix synthesis. At different time points, samples were collected for microscopic, histological, biochemical, and mechanical analyses. Results show chondrocyte attachment, proliferation, and abundant matrix synthesis, completely obliterating the pores of the sponges. RA treatment caused chondrocyte hypertrophy, characterized by the presence of type X collagen in the extracellular matrix and increased alkaline phosphatase activity. In addition, hypertrophy markedly changed the mechanical properties of the chondrocyte/chitosan constructs. In conclusion, we have developed chitosan sponges with adequate pore structure and mechanical properties to serve as a support for hypertrophic chondrocytes. In parallel studies, we have evaluated the ability of this mature cartilage scaffold to induce endochondral ossification. PMID:18759672

  10. Human embryonic stem-cell derivatives for full reconstruction of the pluristratified epidermis: a preclinical study.

    PubMed

    Guenou, Hind; Nissan, Xavier; Larcher, Fernando; Feteira, Jessica; Lemaitre, Gilles; Saidani, Manoubia; Del Rio, Marcela; Barrault, Christine C; Bernard, François-Xavier; Peschanski, Marc; Baldeschi, Christine; Waksman, Gilles

    2009-11-21

    Cell therapy for large burns is dependent upon autologous epidermis reconstructed in vitro. However, the effectiveness of current procedures is limited by the delay needed to culture the patient's own keratinocytes. To assess whether the keratinocyte progeny of human embryonic stem cells (hESCs) could be used to form a temporary skin substitute for use in patients awaiting autologous grafts, we investigated the cells' capability of constructing a pluristratified epidermis. hESCs from lines H9 and SA01 were seeded at least in triplicate on fibroblast feeder cells for 40 days in a medium supplemented with bone morphogenetic protein 4 and ascorbic acid. Molecular characterisation of cell differentiation was done throughout the process by quantitative PCR, fluorescence-activated cell sorting, and immunocytochemical techniques. Keratinocyte molecular differentiation and functional capacity to construct a human epidermis were assessed in vitro and in vivo. From hESCs, we generated a homogeneous population of cells that showed phenotypic characteristics of basal keratinocytes. Expression levels of genes encoding keratin 14, keratin 5, integrin alpha6, integrin beta4, collagen VII, and laminin 5 in these cells were similar to those in basal keratinocytes. After seeding on an artificial matrix, keratinocytes derived from hESCs (K-hESCs) formed a pluristratified epidermis. Keratin-14 immunostaining was seen in the basal compartment, with keratin 10 present in layers overlying the basal layer. Involucrin and filaggrin, late markers of epidermal differentiation, were detected in the uppermost layers only. 12 weeks after grafting onto five immunodeficient mice, epidermis derived from K-hESCs had a structure consistent with that of mature human skin. Human involucrin was appropriately located in spinous and granular layers and few Ki67-positive cells were detected in the basal layer. hESCs can be differentiated into basal keratinocytes that are fully functional--ie, able to

  11. In vivo quantification of bone-fluorine by delayed neutron activation analysis: a pilot study of hand-bone-fluorine levels in a Canadian population.

    PubMed

    Chamberlain, Mike; Gräfe, James L; Aslam; Byun, Soo-Hyun; Chettle, David R; Egden, Lesley M; Webber, Colin E; McNeill, Fiona E

    2012-03-01

    Humans can be exposed to fluorine (F) through their diet, occupation, environment and oral dental care products. Fluorine, at proper dosages, is believed to have positive effects by reducing the incidence of dental caries, but fluorine toxicity can occur when people are exposed to excessive quantities of fluorine. In this paper we present the results of a small pilot in vivo study on 33 participants living in Southwestern Ontario, Canada. The mean age of participants was 45 ± 18 years with a range of 20-87 years. The observed calcium normalized hand-bone-fluorine concentrations in this small pilot study ranged from 1.1 to 8.8 mg F/g Ca. Every person measured in this study had levels of fluorine in bone above the detection limit of the system. The average fluorine concentration in bone was found to be 3.5 ± 0.4 mg F/g Ca. No difference was observed in average concentration for men and women. In addition, a significant correlation (r(2) = 0.55, p < 0.001) was observed between hand-bone-fluorine content and age. The amount of fluorine was found to increase at a rate of 0.084 ± 0.014 mg F/g Ca per year. There was no significant difference observed in this small group of subjects between the accumulation rates in men and women. To the best of our knowledge, this is the first time data from in vivo measurement of fluorine content in humans by neutron activation analysis have been presented. The data determined by this technique were found to be consistent with results from ex vivo studies from other countries. We suggest that the data demonstrate that this low risk non-invasive diagnostic technique will permit the routine assessment of bone-fluorine content with potential application in the study of clinical bone-related diseases. This small study demonstrated that people in Southern Ontario are exposed to fluoride in measureable quantities, and that fluoride can be seen to accumulate in bone with age. However, all volunteers were found to have levels below those

  12. Photodynamic therapy with the phthalocyanine photosensitizer Pc 4: The case experience with preclinical mechanistic and early clinical-translational studies

    SciTech Connect

    Miller, Janine D.; Scull, Heather

    2007-11-01

    Photodynamic therapy (PDT) is emerging as a promising non-invasive treatment for cancers. PDT involves either local or systemic administration of a photosensitizing drug, which preferentially localizes within the tumor, followed by illumination of the involved organ with light, usually from a laser source. Here, we provide a selective overview of our experience with PDT at Case Western Reserve University, specifically with the silicon phthalocyanine photosensitizer Pc 4. We first review our in vitro studies evaluating the mechanism of cell killing by Pc 4-PDT. Then we briefly describe our clinical experience in a Phase I trial of Pc 4-PDT and our preliminary translational studies evaluating the mechanisms behind tumor responses. Preclinical work identified (a) cardiolipin and the anti-apoptotic proteins Bcl-2 and Bcl-xL as targets of Pc 4-PDT, (b) the intrinsic pathway of apoptosis, with the key participation of caspase-3, as a central response of many human cancer cells to Pc 4-PDT, (c) signaling pathways that could modify apoptosis, and (d) a formulation by which Pc 4 could be applied topically to human skin and penetrate at least through the basal layer of the epidermis. Clinical-translational studies enabled us to develop an immunohistochemical assay for caspase-3 activation, using biopsies from patients treated with topical Pc 4 in a Phase I PDT trial for cutaneous T-cell lymphoma. Results suggest that this assay may be used as an early biomarker of clinical response.

  13. Preclinical studies on the reinforcing effects of cannabinoids. A tribute to the scientific research of Dr. Steve Goldberg.

    PubMed

    Tanda, Gianluigi

    2016-05-01

    The reinforcing effects of most abused drugs have been consistently demonstrated and studied in animal models, although those of marijuana were not, until the demonstration 15 years ago that delta-9-tetrahydrocannabinol (THC) could serve as a reinforcer in self-administration (SA) procedures in squirrel monkeys. Until then, those effects were inferred using indirect assessments. The aim of this manuscript is to review the primary preclinical procedures used to indirectly and directly infer reinforcing effects of cannabinoid drugs. Results will be reviewed from studies of cannabinoid discrimination, intracranial self-stimulation (ICSS), conditioned place preference (CPP), as well as change in levels of dopamine assessed in brain areas related to reinforcement, and finally from self-administration procedures. For each procedure, an evaluation will be made of the predictive validity in detecting the potential abuse liability of cannabinoids based on seminal papers, with the addition of selected reports from more recent years especially those from Dr. Goldberg's research group. ICSS and CPP do not provide consistent results for the assessment of potential for abuse of cannabinoids. However, drug discrimination and neurochemistry procedures appear to detect potential for abuse of cannabinoids, as well as several novel "designer cannabinoid drugs." Though after 15 years transfer of the self-administration model of marijuana abuse from squirrel monkeys to other species remains somewhat problematic, studies with the former species have substantially advanced the field, and several reports have been published with consistent self-administration of cannabinoid agonists in rodents.

  14. Preclinical studies in the mdx mouse model of duchenne muscular dystrophy with the histone deacetylase inhibitor givinostat.

    PubMed

    Consalvi, Silvia; Mozzetta, Chiara; Bettica, Paolo; Germani, Massimiliano; Fiorentini, Francesco; Del Bene, Francesca; Rocchetti, Maurizio; Leoni, Flavio; Monzani, Valmen; Mascagni, Paolo; Puri, Pier Lorenzo; Saccone, Valentina

    2013-05-20

    Previous work has established the existence of dystrophin-nitric oxide (NO) signaling to histone deacetylases (HDACs) that is deregulated in dystrophic muscles. As such, pharmacological interventions that target HDACs (that is, HDAC inhibitors) are of potential therapeutic interest for the treatment of muscular dystrophies. In this study, we explored the effectiveness of long-term treatment with different doses of the HDAC inhibitor givinostat in mdx mice--the mouse model of Duchenne muscular dystrophy (DMD). This study identified an efficacy for recovering functional and histological parameters within a window between 5 and 10 mg/kg/d of givinostat, with evident reduction of the beneficial effects with 1 mg/kg/d dosage. The long-term (3.5 months) exposure of 1.5-month-old mdx mice to optimal concentrations of givinostat promoted the formation of muscles with increased cross-sectional area and reduced fibrotic scars and fatty infiltration, leading to an overall improvement of endurance performance in treadmill tests and increased membrane stability. Interestingly, a reduced inflammatory infiltrate was observed in muscles of mdx mice exposed to 5 and 10 mg/kg/d of givinostat. A parallel pharmacokinetic/pharmacodynamic analysis confirmed the relationship between the effective doses of givinostat and the drug distribution in muscles and blood of treated mice. These findings provide the preclinical basis for an immediate translation of givinostat into clinical studies with DMD patients.

  15. Photodynamic therapy with the phthalocyanine photosensitizer Pc 4: the case experience with preclinical mechanistic and early clinical-translational studies.

    PubMed

    Miller, Janine D; Baron, Elma D; Scull, Heather; Hsia, Andrew; Berlin, Jeffrey C; McCormick, Thomas; Colussi, Valdir; Kenney, Malcolm E; Cooper, Kevin D; Oleinick, Nancy L

    2007-11-01

    Photodynamic therapy (PDT) is emerging as a promising non-invasive treatment for cancers. PDT involves either local or systemic administration of a photosensitizing drug, which preferentially localizes within the tumor, followed by illumination of the involved organ with light, usually from a laser source. Here, we provide a selective overview of our experience with PDT at Case Western Reserve University, specifically with the silicon phthalocyanine photosensitizer Pc 4. We first review our in vitro studies evaluating the mechanism of cell killing by Pc 4-PDT. Then we briefly describe our clinical experience in a Phase I trial of Pc 4-PDT and our preliminary translational studies evaluating the mechanisms behind tumor responses. Preclinical work identified (a) cardiolipin and the anti-apoptotic proteins Bcl-2 and Bcl-xL as targets of Pc 4-PDT, (b) the intrinsic pathway of apoptosis, with the key participation of caspase-3, as a central response of many human cancer cells to Pc 4-PDT, (c) signaling pathways that could modify apoptosis, and (d) a formulation by which Pc 4 could be applied topically to human skin and penetrate at least through the basal layer of the epidermis. Clinical-translational studies enabled us to develop an immunohistochemical assay for caspase-3 activation, using biopsies from patients treated with topical Pc 4 in a Phase I PDT trial for cutaneous T-cell lymphoma. Results suggest that this assay may be used as an early biomarker of clinical response.

  16. In vitro study of adhesive polymethylmethacrylate bone cement bonding to cortical bone in maxillofacial surgery.

    PubMed

    Smeets, Ralf; Marx, Rudolf; Kolk, Andreas; Said-Yekta, Sareh; Grosjean, Maurice B; Stoll, Christian; Tinschert, Joachim; Wirtz, Dieter C; Riediger, Dieter; Endres, Kira

    2010-12-01

    In the treatment of midface fractures, the fragments are immobilized using screws and plates for osteosynthesis until reunion has occurred. This method involves drilling holes for the insertion of the screws, which can be associated with additional fracturing of the corresponding bone owing to the complex architecture and thin layers of facial bone. To alleviate this problem, new adhesive techniques for fixing the plates for osteosynthesis have been investigated, mitigating the detrimental effects of screw hole drilling. In the present experimental study, the strength of this adhesive bond and its resistance to hydrolysis were investigated. To determine the adhesive bonding strength, a tension test was implemented. Osteosynthesis plates with screw holes 1.3 mm in diameter were fixed to cortical bone samples of bovine femur using ultraviolet (UV) light-curing polymethylmethacrylate bone cement. To facilitate bonding, the surface of the bone was conditioned with an amphiphilic bonding agent before cementing. UV light curing was implemented using either a conventional UV unit, such as is used in dentistry, or with a specialized UV unit with a limited emission spectrum but high luminosity. Reference control samples were prepared without application of the bone bonding agent. After this procedure, the samples were stored for 1 to 7 days at 37°C submerged in 0.9% saline solution before being subjected to the tension test. Without the bone bonding agent, the bonding strength was 0.2 MPa. The primary average bonding strength at day 0 was 8.5 MPa when cured with the conventional UV unit and 14 MPa for the samples cured with the specialized UV unit. An almost constant average bond strength of 8 and 16 MPa was noted for all samples stored up to 7 days after curing with the conventional and specialized UV unit, respectively. With the development of a new bone bonding agent, a method is now available to promote the bonding between the hydrophilic bone surface and the

  17. Recombinant human bone morphogenic protein-2-enhanced anterior spine fusion without bone encroachment into the spinal canal: a histomorphometric study in a thoracoscopically instrumented porcine model.

    PubMed

    Zhang, Hong; Sucato, Daniel J; Welch, Robert D

    2005-03-01

    A thoracoscopically assisted 5-level anterior spinal fusion and instrumentation model analyzing new bone formation when using recombinant human bone morphogenic protein-2 (rhBMP-2) with a collagen hydroxyapatite-tricalcium phosphate (HA/TCP) composite sponge carrier. To determine whether new bone formation extends beyond the posterior confines of the vertebral body encroaching into the spinal canal when rhBMP-2 is used to enhance anterior fusion. A possible concern regarding the use of rhBMP-2 to enhance spinal fusion is the risk of unwanted bone formation leading to inadvertent fusion of adjacent levels or compression of neural elements. The safety of rhBMP-2 in one spinal application does not ensure similar results in other applications. Therefore, the expanded use of rhBMP-2 should occur only after carefully monitored preclinical and clinical studies for each new application. Eighteen pigs underwent thoracoscopically-assisted instrumentation and fusion of 5 contiguous levels (T5-T10) and randomly assigned to 4 treatment groups: group 1 (n = 6): rh-BMP-2 on a HA/TCP-collagen sponge (Medtronic Sofamor Danek, Memphis, TN); group 2 (n = 4): iliac crest autograft; group 3 (n = 4): empty; group 4 (n = 4): HA/TCP-collagen sponge (Medtronic Sofamor Danek) only. In groups 1 and 4, the HA/TCP collagen sponge was morselized into small granules and pushed through a bone delivery funnel for implantation into the disc. At 4 months after surgery, spines were sectioned longitudinally through the midsagittal plane and underwent undecalcified processing. Bone formation extending beyond the margins of the original discectomy and the confines of vertebral body were evaluated histomorphometrically at each operative level. Recombinant human bone morphogenic protein-2 on a HA/TCP-collagen sponge induced significant new bone formation extending anterior to the confines of the vertebral body compared with the other treatment groups (P < 0.05). In addition, rhBMP-2 on a HA

  18. Minnelide reduces tumor burden in preclinical models of osteosarcoma

    PubMed Central

    Banerjee, Sulagna; Thayanithy, Venugopal; Sangwan, Veena; Mackenzie, Tiffany N.; Saluja, Ashok K.; Subramanian, Subbaya

    2015-01-01

    Osteosarcoma is the most common bone cancer in children and adolescents with a five-year survival rate of about 70%. In this study, we have evaluated the preclinical therapeutic efficacy of the novel synthetic drug, Minnelide, a prodrug of triptolide on osteosarcoma. Triptolide was effective in significantly inducing apoptosis in all osteosarcoma cell lines tested but had no significant effect on the human osteoblast cells. Notably, Minnelide treatment significantly reduced tumor burden and lung metastasis in the orthotopic and lung colonization models. Triptolide/Minnelide effectively downregulated the levels of pro-survival proteins such as heat shock proteins, cMYC, survivin and targets NF-κB pathway. PMID:23499892

  19. Curcumin nanoformulations: a review of pharmaceutical properties and preclinical studies and clinical data related to cancer treatment.

    PubMed

    Naksuriya, Ornchuma; Okonogi, Siriporn; Schiffelers, Raymond M; Hennink, Wim E

    2014-03-01

    Curcumin, a natural yellow phenolic compound, is present in many kinds of herbs, particularly in Curcuma longa Linn. (turmeric). It is a natural antioxidant and has shown many pharmacological activities such as anti-inflammatory, anti-microbial, anti-cancer, and anti-Alzheimer in both preclinical and clinical studies. Moreover, curcumin has hepatoprotective, nephroprotective, cardioprotective, neuroprotective, hypoglycemic, antirheumatic, and antidiabetic activities and it also suppresses thrombosis and protects against myocardial infarction. Particularly, curcumin has demonstrated efficacy as an anticancer agent, but a limiting factor is its extremely low aqueous solubility which hampers its use as therapeutic agent. Therefore, many technologies have been developed and applied to overcome this limitation. In this review, we summarize the recent works on the design and development of nano-sized delivery systems for curcumin, including liposomes, polymeric nanoparticles and micelles, conjugates, peptide carriers, cyclodextrins, solid dispersions, lipid nanoparticles and emulsions. Efficacy studies of curcumin nanoformulations using cancer cell lines and in vivo models as well as up-to-date human clinical trials are also discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Assessment of Cardiac Troponin I Responses in Nonhuman Primates during Restraint, Blood Collection, and Dosing in Preclinical Safety Studies.

    PubMed

    Reagan, William J; Barnes, Robert; Harris, Peter; Summers, Sandy; Lopes, Sarah; Stubbs, Makeida; Blackwell, David; Steidl-Nichols, Jill

    2017-02-01

    Limited information has been published on the use of cardiac troponin I (cTnI) as a biomarker of cardiac injury in monkeys. The purpose of these studies was to characterize the cTnI response seen in cynomolgus macaques during routine dosing and blood collection procedures typically used in preclinical safety studies and to better understand the pathogenesis of this response. We measured cTnI using two different methods, the Siemens Immulite cTnI assay and the more sensitive Siemens Troponin I-Ultra assay. We were able to demonstrate that after oral, subcutaneous, or intravenous dosing of common vehicles, as well as serial chair restraint for venipuncture blood collection, that minimal to mild transient increases in cTnI could be detected in monkeys with both assays. cTnI values typically peaked at 2, 3, 4, or 6 hr after sham dosing and returned to baseline at 22 or 24 hr. In addition, marked increases in heart rate (HR) and blood pressure (BP) occurred in monkeys during the restraint procedures, which likely initiated the cTnI release in these animals. Monkeys that were very well acclimated to the chairing procedures and had vascular access ports for blood sampling did not have marked increases in HRs and BP or increases in cTnI.

  1. An observational study investigating the impact of simulated patients in teaching communication skills in preclinical dietetic students.

    PubMed

    Gibson, S J; Davidson, Z E

    2016-08-01

    Simulated patients (SPs) are often used in dietetics for the teaching and assessment of communication skills. The present study aimed to determine the impact of a SP encounter on communication skills in undergraduate preclinical dietetic students in the context of the resources required for delivering this educational strategy. This observational study collected assessment data from four cohorts of third-year dietetic students to examine the effect of participation in SP-embedded Objective Structured Clinical Exams. Students completed two SP interviews, 2 weeks apart, and communication skills were measured on both occasions. A subgroup of students received a video of their SP encounter. Differences between the two SP interview scores were compared to assess the impact of the SP encounter on communication skills. The required staff and resources were described. Data were collected involving 215 students. Out of 30 marks, there was a modest mean (SD) improvement in communication skills from the first to the second SP interview of 2.5 (4.2) (P < 0.01). There was an association between student ability and improvement in communication skills, with failing students demonstrating the greatest improvement between SP encounters. There were no observed benefits for the subset of students who received videos. Providing repeat SP interview opportunities results in only modest improvement in communication skills for most students. The use of SPs needs to be considered in context of the substantial costs and resources involved and tailored to student ability. © 2015 The British Dietetic Association Ltd.

  2. Pre-clinical toxicokinetics and safety study of M2ES, a PEGylated recombinant human endostatin, in rhesus monkeys.

    PubMed

    Guo, Lifang; Geng, Xingchao; Chen, Yang; Qi, Feifei; Liu, Li; Miao, Yufa; Lin, Zhi; Yu, Min; Li, Zuogang; Fu, Yan; Li, Bo; Luo, Yongzhang

    2014-08-01

    PEGylated recombinant human endostatin (M2ES) exhibited prolonged serum half-life and enhanced antitumor activity when compared with endostatin. A non-clinical study was performed to evaluate the toxicokinetics and safety of M2ES in rhesus monkeys. After intravenous (IV) infusions of M2ES at a dose level of 3, 10, and 30mg/kg in rhesus monkeys, the concentration-time curves of M2ES were best fitted to a non-compartment model, and area under the curve (AUC) was positively correlated with the dosage. M2ES had a tendency to accumulate in vivo following successive IV infusions. Serum anti-M2ES IgG antibodies were generated quickly during IV administration, and the antibody level in serum did not significantly decrease after four-week recovery period. Animals administered IV infusions twice weekly (M2ES at 10 or 30mg/kg body weight per day) for 3months developed mild or moderate vacuolation of proximal tubule epithelial cell in proximal convoluted tubule of kidney, but this adverse-effect was reversible. In summary, M2ES was well tolerated and did not cause any serious toxicity. These pre-clinical safety data contribute to the initiation of the ongoing clinical study. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Reform in Teaching Preclinical Pathophysiology

    ERIC Educational Resources Information Center

    Li, Yong-Yu; Li, Kun; Yao, Hong; Xu, Xiao-Juan; Cai, Qiao-Lin

    2015-01-01

    Pathophysiology is a scientific discipline that studies the onset and progression of pathological conditions and diseases, and pathophysiology is one of the core courses in most preclinical medical curricula. In China, most medical schools house a Department of Pathophysiology, in contrast to medical schools in many developed countries. The staff…

  4. Reform in Teaching Preclinical Pathophysiology

    ERIC Educational Resources Information Center

    Li, Yong-Yu; Li, Kun; Yao, Hong; Xu, Xiao-Juan; Cai, Qiao-Lin

    2015-01-01

    Pathophysiology is a scientific discipline that studies the onset and progression of pathological conditions and diseases, and pathophysiology is one of the core courses in most preclinical medical curricula. In China, most medical schools house a Department of Pathophysiology, in contrast to medical schools in many developed countries. The staff…

  5. A review of treatment planning for precision image-guided photon beam pre-clinical animal radiation studies.

    PubMed

    Verhaegen, Frank; van Hoof, Stefan; Granton, Patrick V; Trani, Daniela

    2014-12-01

    Recently, precision irradiators integrated with a high-resolution CT imaging device became available for pre-clinical studies. These research platforms offer significant advantages over older generations of animal irradiators in terms of precision and accuracy of image-guided radiation targeting. These platforms are expected to play a significant role in defining experiments that will allow translation of research findings to the human clinical setting. In the field of radiotherapy, but also others such as neurology, the platforms create unique opportunities to explore e.g. the synergy between radiation and drugs or other agents. To fully exploit the advantages of this new technology, accurate methods are needed to plan the irradiation and to calculate the three-dimensional radiation dose distribution in the specimen. To this end, dedicated treatment planning systems are needed. In this review we will discuss specific issues for precision irradiation of small animals, we will describe the workflow of animal treatment planning, and we will examine several dose calculation algorithms (factorization, superposition-convolution, Monte Carlo simulation) used for animal irradiation with kilovolt photon beams. Issues such as dose reporting methods, photon scatter, tissue segmentation and motion will also be discussed briefly. Copyright © 2014. Published by Elsevier GmbH.

  6. (99m)Tc-amitrole as a novel selective imaging probe for solid tumor: In silico and preclinical pharmacological study.

    PubMed

    Essa, B M; Sakr, T M; Khedr, Mohammed A; El-Essawy, F A; El-Mohty, A A

    2015-08-30

    Lactoperoxidase (LPO) inhibitors are very selective for solid tumor due to their high binding affinity to the LPO enzyme. A computational study was used to select top-ranked LPO inhibitor (alone and in complex with (99m)Tc) with high in silico affinity. The novel prepared (99m)Tc-amitrole complex demonstrated both in silico and in vivo high affinity toward solid tumors.(99m)Tc-amitrole was radio-synthesized with a high radiochemical yield (89.7±3.25). It showed in vitro stability for up to 6h. Its preclinical evaluation in solid tumor-bearing mice showed high retention and biological accumulation in solid tumor cells with a high Target/Non-Target (T/NT) ratio equal to 4.9 at 60min post-injection. The data described previously could recommend (99m)Tc-amitrole as potential targeting scintigraphic probe for solid tumor imaging. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Kidney Injury Molecule-1 Outperforms Traditional Biomarkers of Kidney Injury in Multi-site Preclinical Biomarker Qualification Studies

    PubMed Central

    Vaidya, Vishal S.; Ozer, Josef S.; Frank, Dieterle; Collings, Fitz B.; Ramirez, Victoria; Troth, Sean; Muniappa, Nagaraja; Thudium, Douglas; Gerhold, David; Holder, Daniel J.; Bobadilla, Norma A.; Marrer, Estelle; Perentes, Elias; Cordier, André; Vonderscher, Jacky; Maurer, Gérard; Goering, Peter L.; Sistare, Frank D.; Bonventre, Joseph V.

    2010-01-01

    Kidney toxicity accounts for a significant percentage of morbidity and drug candidate failure. Serum creatinine (SCr) and blood urea nitrogen (BUN) have been used to monitor kidney dysfunction for over a century but these markers are insensitive and non-specific. In multi-site preclinical rat toxicology studies the diagnostic performance of urinary kidney injury molecule-1 (Kim-1) was compared to traditional biomarkers as predictors of kidney tubular histopathologic changes, currently considered the “gold standard” of nephrotoxicity. In multiple models of kidney injury, urinary Kim-1 significantly outperformed SCr and BUN. The area under the receiver operating characteristic curve for Kim-1 was between 0.91 and 0.99 as compared to 0.79 to 0.9 for BUN and 0.73 to 0.85 for SCr. Thus urinary Kim-1 is the first injury biomarker of kidney toxicity qualified by the FDA and EMEA and is expected to significantly improve kidney safety monitoring. PMID:20458318

  8. MKT-077, a novel rhodacyanine dye in clinical trials, exhibits anticarcinoma activity in preclinical studies based on selective mitochondrial accumulation.

    PubMed

    Koya, K; Li, Y; Wang, H; Ukai, T; Tatsuta, N; Kawakami, M; Shishido; Chen, L B

    1996-02-01

    MKT-077 (formerly known as FJ-776) is a newly synthesized, highly water-soluble ( > 200 mg/ml) rhodacyanine dye that exhibits significant antitumor activity in a variety of model systems. In culture, MKT-077 inhibits the growth of five human cancer cell lines (colon carcinoma CX-1, breast carcinoma MCF-7, pancreatic carcinoma (CRL 1420, bladder transitional cell carcinoma EJ, and melanoma LOX) but not monkey kidney CV-1, an indicator cell line for normal epithelial cells. In nude mice, MKT-077 inhibits the growth of s.c. implanted human renal carcinoma A498 and human prostate carcinoma DU145 and prolongs the survival of mice bearing i.p. implanted human melanoma LOX (tumor:control = 344%). Subcellular localization indicates that MKT-077 is taken up and retained by mitochondria, and flow cytometric analysis suggests that CX-1 cells take up MKT-077 to a much greater extent than CV-1 cells. Quantitation of MKT-077 uptake by ethanol extraction shows that CX-1 cells accumulate 65-fold more MKT-077 than do CV-1 cells. MKT-077 is the first delocalized lipophilic cation with a favorable pharmacological and toxicological profile in preclinical studies. MKT-077 is now being investigated in Phase I clinical trials.

  9. Volume cerebral blood flow reduction in pre-clinical stage of Alzheimer disease: evidence from an ultrasonographic study.

    PubMed

    Maalikjy Akkawi, Nabil; Borroni, B; Agosti, C; Magoni, M; Broli, M; Pezzini, A; Padovani, A

    2005-05-01

    The association of decreased cerebral blood flow with the development of Alzheimer's disease (AD) has been a recent target of interest. By using neuroimaging techniques, growing attention has been devoted to the identification of preclinical AD. In this study, color duplex sonography of cervical arteries was used to measure mean cerebral blood flow (CBF) on 55 amnestic Mild Cognitive Impairment (MCI) patients. Two years after enrollment, excluding patients who progressed to dementia other than AD, two subgroups were identified, patients who developed AD (MCI converters) and patients with preserved cognitive and functional level (MCI non-converters). Examining the mean difference of CBF measured at baseline in the two subgroups obtained, a significant difference was noticed (MCI converters 539.3 +/- 114.3 vs MCI non converters 636.0 +/- 143.9, p < 0.05). MCI patients with CBF higher than median value (558 ml/min) had lower risk of developing AD (specificity 72.2%, sensitivity 68.4%) within a two year follow-up. Ultrasonography of the cervical arteries is a simple, non invasive and widespread technique useful in detecting CBF decline during the MCI stage, thus identifying patients who later will convert to AD.

  10. BLOCKING CANNABINOID CB1 RECEPTORS FOR THE TREATMENT OF NICOTINE DEPENDENCE: INSIGHTS FROM PRECLINICAL AND CLINICAL STUDIES

    PubMed Central

    Le Foll, Bernard; Forget, Benoit; Aubin, Henri-Jean; Goldberg, Steven R.

    2009-01-01

    Tobacco use is one of the leading preventable causes of death in developed countries. Since existing medications are only partially effective in treating tobacco smokers, there is a great need for improved medications for smoking cessation. It has been recently proposed that cannabinoid CB1 receptor antagonists represent a new class of therapeutic agents for drug dependence, and, notably, nicotine dependence. Here, we will review current evidence supporting the use of this class of drugs for smoking cessation treatment. Preclinical studies indicate that nicotine exposure produces changes in endocannabinoid content in the brain. In experimental animals, Rimonabant (SR141716) and AM251, two cannabinoid CB1 receptor antagonists, block nicotine self-administration behavior, an effect that may be related to the blockade of the dopamine-releasing effects of nicotine in the brain. Rimonabant also seems efficacious in decreasing the influence of nicotine-associated stimuli over behavior, suggesting that it may act on two distinct neuronal pathways, those implicated in drug-taking behavior and those involved in relapse phenomena. The utility of Rimonabant has been evaluated in several clinical trials. It seems that Rimonabant is an efficacious treatment for smoking cessation, although its efficacy doesn’t exceed that of nicotine replacement therapy and its use may be limited by emotional side effects (nausea, anxiety and depression, mostly). Rimonabant also appears to decrease relapse rates in smokers. These findings indicate significant, but limited, utility of Rimonabant for smoking cessation. PMID:18482433

  11. Extracorporeal hydroxyapatite-chamber for bone and biomaterial studies.

    PubMed

    Tarallo, Luigi; Zaffe, Davide; Adani, Roberto; Krajewski, Adriano; Ravaglioli, Antonio

    2008-01-01

    Hydroxyapatite (HA) spherules and autologous bone (AB) with a central vascular pedicle were housed inside an HA-chamber to form the skeletal segment of specific shape. Experimental chambers were then inserted in a pocket between medial thigh muscles in 13 New Zealand male rabbits for 3 months. Three graft group were scheduled: (A) HA and AB without vascular pedicle, (B) HA with vascular pedicle, (C) HA and AB with vascular pedicle. At term, histology showed tissue and cellular degeneration in group A chambers. Due to spherules coalescence, fibrous tissue is formed in group B chambers. Group C chambers contained living osteocytes in the implanted bone, several newly formed vessels in soft tissue, bone and partial hydroxyapatite erosions. New bone was formed in apposition to both autologous bone and hydroxyapatite. Our study suggests that this experimental model could be used to grow adequately sized vascularized skeletal segments.

  12. Studies of Bone Morphogenetic Protein based Surgical Repair

    PubMed Central

    Lo, Kevin W.-H.; Ulery, Bret D.; Ashe, Keshia M.; Laurencin, Cato T.

    2012-01-01

    Over the past several decades, recombinant human bone morphogenetic proteins (rhBMPs) have been the most extensively studied and widely used osteoinductive agents for clinical bone repair. Since rhBMP-2 and rhBMP-7 were approved by the U.S. Food and Drug Administration for certain clinical uses, millions of patients worldwide have been treated with rhBMPs for various musculoskeletal disorders. Current clinical applications include treatment of long bone fracture non-unions, spinal surgeries, and oral maxillofacial surgeries. Considering the growing number of recent publications related to clincal research of rhBMPs, there exists enormous promise for these proteins to be used in bone regenerative medicine. The authors take this opportunity to review the rhBMP literature paying specific attention to the current applications of rhBMPs in bone repair and spine surgery. The prospective future of rhBMPs delivered in combination with tissue engineered scaffolds is also reviewed. PMID:22512928

  13. Preclinical pharmacology and toxicology study of Ad-hTERT-E1a-Apoptin, a novel dual cancer-specific oncolytic adenovirus

    SciTech Connect

    Qi, Yanxin; Guo, Huanhuan; Hu, Ningning; He, Dongyun; Zhang, Shi; Chu, Yunjie; Huang, Yubin; Li, Xiao; Sun, LiLi; Jin, Ningyi

    2014-10-15

    Clinical studies have demonstrated that conditionally replicating adenovirus is safe. We constructed an oncolytic adenovirus, Ad-hTERT-E1a-Apoptin, using a cancer-specific promoter (human telomerase reverse transcriptase promoter, hTERTp) and a cancer cell-selective apoptosis-inducing gene (Apoptin). Ad-hTERT-E1a-Apoptin was proven effective both in vitro and in vivo in our previous study. In this study, the preclinical safety profiles of Ad-hTERT-E1a-Apoptin in animal models were investigated. At doses of 5.0 × 10{sup 8}, 2.5 × 10{sup 9}, and 1.25 × 10{sup 10} viral particles (VP)/kg, Ad-hTERT-E1a-Apoptin had no adverse effects on mouse behavior, muscle cooperation, sedative effect, digestive system, and nervous systems, or on beagle cardiovascular and respiratory systems at 5.0 × 10{sup 8}, 2.5 × 10{sup 9}, and 1.25 × 10{sup 10} VP/kg doses. In acute toxicity tests in mice, the maximum tolerated dose > 5 × 10{sup 10} VP/kg. There was no inflammation or ulceration at the injection sites within two weeks. In repeat-dose toxicological studies, the no observable adverse effect levels of Ad-hTERT-E1a-Apoptin in rats (1.25 × 10{sup 10} VP/kg) and beagles (2.5 × 10{sup 9} VP/kg) were 62.5- and 12.5-fold of the proposed clinical dose, respectively. The anti-virus antibody was produced in animal sera. Bone marrow examination revealed no histopathological changes. Guinea pigs sensitized by three repeated intraperitoneal injections of 1.35 × 10{sup 10} VP/mL Ad-hTERT-E1a-Apoptin each and challenged by one intravenous injection of 1.67 × 10{sup 8} VP/kg Ad-hTERT-E1a-Apoptin did not exhibit any sign of systemic anaphylaxis. Our data from different animal models suggest that Ad-hTERT-E1a-Apoptin is a safe anti-tumor therapeutic agent. - Highlights: • We use the rodents and non-rodents animal models to evaluation Ad-hTERT-E1a-Apoptin. • Ad-hTERT-E1a-Apoptin is a safe anti-tumor therapeutic agent. • Demonstrate the safety and feasibility dose of injected Ad

  14. Preclinical pharmacology and toxicology study of Ad-hTERT-E1a-Apoptin, a novel dual cancer-specific oncolytic adenovirus.

    PubMed

    Qi, Yanxin; Guo, Huanhuan; Hu, Ningning; He, Dongyun; Zhang, Shi; Chu, Yunjie; Huang, Yubin; Li, Xiao; Sun, LiLi; Jin, Ningyi

    2014-10-15

    Clinical studies have demonstrated that conditionally replicating adenovirus is safe. We constructed an oncolytic adenovirus, Ad-hTERT-E1a-Apoptin, using a cancer-specific promoter (human telomerase reverse transcriptase promoter, hTERTp) and a cancer cell-selective apoptosis-inducing gene (Apoptin). Ad-hTERT-E1a-Apoptin was proven effective both in vitro and in vivo in our previous study. In this study, the preclinical safety profiles of Ad-hTERT-E1a-Apoptin in animal models were investigated. At doses of 5.0×10(8), 2.5×10(9), and 1.25×10(10) viral particles (VP)/kg, Ad-hTERT-E1a-Apoptin had no adverse effects on mouse behavior, muscle cooperation, sedative effect, digestive system, and nervous systems, or on beagle cardiovascular and respiratory systems at 5.0×10(8), 2.5×10(9), and 1.25×10(10) VP/kg doses. In acute toxicity tests in mice, the maximum tolerated dose>5×10(10) VP/kg. There was no inflammation or ulceration at the injection sites within two weeks. In repeat-dose toxicological studies, the no observable adverse effect levels of Ad-hTERT-E1a-Apoptin in rats (1.25×10(10) VP/kg) and beagles (2.5×10(9) VP/kg) were 62.5- and 12.5-fold of the proposed clinical dose, respectively. The anti-virus antibody was produced in animal sera. Bone marrow examination revealed no histopathological changes. Guinea pigs sensitized by three repeated intraperitoneal injections of 1.35×10(10) VP/mL Ad-hTERT-E1a-Apoptin each and challenged by one intravenous injection of 1.67×10(8) VP/kg Ad-hTERT-E1a-Apoptin did not exhibit any sign of systemic anaphylaxis. Our data from different animal models suggest that Ad-hTERT-E1a-Apoptin is a safe anti-tumor therapeutic agent. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Development of an ex vivo human-porcine respiratory model for preclinical studies.

    PubMed

    Perinel, Sophie; Pourchez, Jérémie; Leclerc, Lara; Avet, John; Durand, Marc; Prévôt, Nathalie; Cottier, Michèle; Vergnon, Jean M

    2017-02-24

    Anatomical models to study aerosol delivery impose huge limitations and extrapolation to humans remains controversial. This study aimed to develop and validate an ex vivo human-like respiratory tract model easy to use and relevant to compare to in vivo human data. A human plastinated head is connected to an ex vivo porcine pulmonary tract ventilated artificially by passive expansion. A physiological study measures "pleural" depressions, tidal volumes, and minute ventilation for the respiratory rates chosen (10, 15, and 20 per minute) with three inspiratory/expiratory ratios (1/1, 1/2, and 1/3). Scintigraphy with (81m)Krypton assesses the homogeneity of the ventilation. Forty different experiments were set for validation, with 36 (90%) ventilating successfully. At a respiratory rate of 15/minute with inspiratory/expiratory ratio of 1/2, the tidal volume average was 824 mL (standard deviation, 207 mL). The scintigraphy performed on 16 ex vivo models (44.4%), showed homogenous ventilation with great similarity to human physiological studies. Ratio of the peripheral to central count rates were equally correlated with human data published in the literature. This new model, combining research feasibility and human physiology likeness, provides a realistic approach to human inhalation and therefore can be an interesting tool in aerosol regional deposition studies.

  16. Development of an ex vivo human-porcine respiratory model for preclinical studies

    PubMed Central

    Perinel, Sophie; Pourchez, Jérémie; Leclerc, Lara; Avet, John; Durand, Marc; Prévôt, Nathalie; Cottier, Michèle; Vergnon, Jean M.

    2017-01-01

    Anatomical models to study aerosol delivery impose huge limitations and extrapolation to humans remains controversial. This study aimed to develop and validate an ex vivo human-like respiratory tract model easy to use and relevant to compare to in vivo human data. A human plastinated head is connected to an ex vivo porcine pulmonary tract ventilated artificially by passive expansion. A physiological study measures “pleural” depressions, tidal volumes, and minute ventilation for the respiratory rates chosen (10, 15, and 20 per minute) with three inspiratory/expiratory ratios (1/1, 1/2, and 1/3). Scintigraphy with 81mKrypton assesses the homogeneity of the ventilation. Forty different experiments were set for validation, with 36 (90%) ventilating successfully. At a respiratory rate of 15/minute with inspiratory/expiratory ratio of 1/2, the tidal volume average was 824 mL (standard deviation, 207 mL). The scintigraphy performed on 16 ex vivo models (44.4%), showed homogenous ventilation with great similarity to human physiological studies. Ratio of the peripheral to central count rates were equally correlated with human data published in the literature. This new model, combining research feasibility and human physiology likeness, provides a realistic approach to human inhalation and therefore can be an interesting tool in aerosol regional deposition studies. PMID:28233793

  17. Study of photoacoustic measurement of bone health based on clinically relevant models

    NASA Astrophysics Data System (ADS)

    Feng, Ting; Kozloff, Ken; Cao, Meng; Cheng, Qian; Yuan, Jie; Wang, Xueding

    2016-02-01

    Photoacoustic (PA) technique involving both ultrasound and light has been explored for potential application in the assessment of bone health. The optical and ultrasound penetration in bone have been studied. The feasibility of conducting 3D PA imaging of bone, and performing quantitative evaluation of bone microstructures by using photoacoustic spectrum analysis (PASA) has also been investigated. The findings from the experiments demonstrate that PA measurement could offer information of bone mineral density and bone microstructure, both relevant to bone health.

  18. [Experimental study of ectopic bone formation of engineered bone constructs under the periosteum of New-Zealand rabbits].

    PubMed

    Zhou, Qiang; Wang, Yang; Yu, Jie; Yu, Ying-hao

    2011-10-01

    To study the feasibility of ectopic bone formation for engineered bone constructs with bone marrow stromal cells (BMSCs). BMSCs were obtained from 3-month female New-Zealand rabbits with weight of 3 kg, induced to osteogenitor cell, were expanded by culture and then seeded into the porous beta-tricalcium phosphate (beta-TCP) particles. Engineered bone constructs were implanted under the periostem of rabbit femur. Samples were retrieved and examed after 3 months. Blood vessels and osteoblast were examined through optical microscope. Twelve implanted engineered bone particles of 16 samples were fixed well under periosteum and rounded by periosteum. There were a lot of vessels and new bone in engineered bone. The structure of bone was disorder; the vessels arranged equally. Four cases found implanted bone freed outside of periosteum,lots of implanted material were absorbed,the volume of residual was less than osteogenesis, and lack of blood vessel. 80% engineered bone constructs attached to the femur under the periostem very well,osteogenesis was fine and vessels were growed into new bone. Engineered bone can obtained good ectopic bone under the periostem.

  19. Bone loss in chronic hemiplegia: a longitudinal cohort study.

    PubMed

    de Brito, Christina May Moran; Garcia, Ana Cristina Ferreira; Takayama, Liliam; Fregni, Felipe; Battistella, Linamara Rizzo; Pereira, Rosa Maria Rodrigues

    2013-01-01

    The purpose of this study was to evaluate hemiplegic stroke patients in terms of long-term changes in bone mineral density and related factors. We conducted a longitudinal cohort study, involving 57 first-stroke patients (40 males) with chronic hemiplegia (for more than 12mo), at a university rehabilitation center in the city of São Paulo, Brazil. Bone loss, body composition, lean mass, and fat mass were evaluated at 2 time points (mean interval, 16mo). Bone loss was significantly greater in paretic forearms than in nonparetic forearms (p=0.001) and in patients having suffered strokes more recently (p=0.015). We found no difference between paretic and nonparetic femurs. Femoral bone loss was significantly greater in patients using anticoagulants or anticonvulsants (p=0.025) and in those with greater spasticity (p=0.040), regardless of the time since stroke. Our results provide additional evidence that hemiplegic stroke patients have progressive bone loss and that such bone loss is more common in the arms than in the legs. Patients with poststroke hemiplegia should be densitometric monitored mainly in paretic arm and treated for bone loss, with attention to the determinants identified in this study. Copyright © 2013 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  20. Synchrotron Study of Strontium in Modern and Ancient Human Bones

    NASA Astrophysics Data System (ADS)

    Pingitore, N. E.; Cruz-Jimenez, G.

    2001-05-01

    Archaeologists use the strontium in human bone to reconstruct diet and migration in ancient populations. Because mammals discriminate against strontium relative to calcium, carnivores show lower bone Sr/Ca ratios than herbivores. Thus, in a single population, bone Sr/Ca ratios can discriminate a meat-rich from a vegetarian diet. Also, the ratio of 87-Sr to 86-Sr in soils varies with the underlying geology; incorporated into the food chain, this local signature becomes embedded in our bones. The Sr isotopic ratio in the bones of individuals or populations which migrate to a different geologic terrane will gradually change as bone remodels. In contrast, the isotopic ratio of tooth enamel is fixed at an early age and is not altered later in life. Addition of Sr to bone during post-mortem residence in moist soil or sediment compromises application of the Sr/Ca or Sr-isotope techniques. If this post-mortem Sr resides in a different atomic environment than the Sr deposited in vivo, x-ray absorption spectroscopy could allow us to distinguish pristine from contaminated, and thus unreliable, samples. Initial examination of a suite of modern and ancient human and animal bones by extended x-ray absorption fine structure (EXAFS) showed no obvious differences between the fresh and buried materials. We note, with obvious concern, that the actual location of Sr in modern bone is controversial: there is evidence both that Sr substitutes for Ca and that Sr is sorbed on the surfaces of bone crystallites. Additional material is being studied.

  1. Metabolic phenotyping applied to pre-clinical and clinical studies of acetaminophen metabolism and hepatotoxicity.

    PubMed

    Coen, Muireann

    2015-02-01

    Acetaminophen (APAP, paracetamol, N-acetyl-p-aminophenol) is a widely used analgesic that is safe at therapeutic doses but is a major cause of acute liver failure (ALF) following overdose. APAP-induced hepatotoxicity is related to the formation of an electrophilic reactive metabolite, N-acetyl-p-benzoquinone imine (NAPQI), which is detoxified through conjugation with reduced glutathione (GSH). One method that has been applied to study APAP metabolism and hepatotoxicity is that of metabolic phenotyping, which involves the study of the small molecule complement of complex biological samples. This approach involves the use of high-resolution analytical platforms such as NMR spectroscopy and mass spectrometry to generate information-rich metabolic profiles that reflect both genetic and environmental influences and capture both endogenous and xenobiotic metabolites. Data modeling and mining and the subsequent identification of panels of candidate biomarkers are typically approached with multivariate statistical tools. We review the application of multi-platform metabolic profiling for the study of APAP metabolism in both in vivo models and humans. We also review the application of metabolic profiling for the study of endogenous metabolic pathway perturbations in response to APAP hepatotoxicity, with a particular focus on metabolites involved in the biosynthesis of GSH and those that reflect mitochondrial function such as long-chain acylcarnitines. Taken together, this body of work sheds much light on the mechanism of APAP-induced hepatotoxicity and provides candidate biomarkers that may prove of translational relevance for improved stratification of APAP-induced ALF.

  2. Choosing preclinical study models of diabetic retinopathy: key problems for consideration

    PubMed Central

    Mi, Xue-Song; Yuan, Ti-Fei; Ding, Yong; Zhong, Jing-Xiang; So, Kwok-Fai

    2014-01-01

    Diabetic retinopathy (DR) is the most common complication of diabetes mellitus in the eye. Although the clinical treatment for DR has already developed to a relative high level, there are still many urgent problems that need to be investigated in clinical and basic science. Currently, many in vivo animal models and in vitro culture systems have been applied to solve these problems. Many approaches have also been used to establish different DR models. However, till now, there has not been a single study model that can clearly and exactly mimic the developmental process of the human DR. Choosing the suitable model is important, not only for achieving our research goals smoothly, but also, to better match with different experimental proposals in the study. In this review, key problems for consideration in choosing study models of DR are discussed. These problems relate to clinical relevance, different approaches for establishing models, and choice of different species of animals as well as of the specific in vitro culture systems. Attending to these considerations will deepen the understanding on current study models and optimize the experimental design for the final goal of preventing DR. PMID:25429204

  3. Preclinical toxicology studies with the new dopamine agonist pergolide. Acute, subchronic, and chronic evaluations.

    PubMed

    Francis, P C; Carlson, K H; Owen, N V; Adams, E R

    1994-03-01

    Pergolide (LY127809, CAS 66104-23-2), a dopamine agonist for the treatment of Parkinson's disease, was evaluated for toxicity in acute, subchronic, and chronic studies. Acute toxicity tests using oral, intravenous and intraperitoneal routes were conducted in rats, mice, rabbits, and dogs. The acute oral median lethal doses (MLD) ranged from 8.4 to 33.6 mg/kg in Wistar and Fischer 344 rats, and from 54.0 to 87.2 mg/kg in ICR mice. Oral doses of 20 and 25 mg/kg produced no mortality in rabbits or dogs, respectively. The MLD by the iv route ranged from 0.59 to 0.87 mg/kg for Fischer 344 rats and from 11.6 to 37.1 mg/kg for ICR mice. The predominant signs of toxicity in the acute studies included hyperactivity, poor grooming, ptosis, aggressive behavior, increased gnawing activity, tremors, convulsions, and emesis. In the subchronic and chronic studies, Fischer 344 rats, B6C3F1 mice, and beagle dogs were administered pergolide either by gavage or in the diet for up to 1 year. Daily doses in these studies ranged up to 20 mg/kg for rats, 45 mg/kg for mice, and 5 mg/kg for dogs. The predominant treatment-related effects seen in these studies were attributable to the pharmacologic activity of pergolide. These consisted primarily of CNS-mediated clinical signs in rats and dogs, weight loss or decreased weight gain, emesis in dogs, and inhibition of lysis of corpora lutea with a corresponding increase in the weight of the uterus and ovaries. Pergolide treatment was not associated with any specific target organ toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. A prospective study on the effectiveness of newly developed autogenous tooth bone graft material for sinus bone graft procedure

    PubMed Central

    Jun, Sang-Ho; Ahn, Jin-Soo; Lee, Jae-Il; Ahn, Kyo-Jin; Yun, Pil-Young

    2014-01-01

    PURPOSE The purpose of this prospective study was to evaluate the effectiveness of newly developed autogenous tooth bone graft material (AutoBT)application for sinus bone graft procedure. MATERIALS AND METHODS The patients with less than 5.0 mm of residual bone height in maxillary posterior area were enrolled. For the sinus bone graft procedure, Bio-Oss was grafted in control group and AutoBT powder was grafted in experimental group. Clinical and radiographic examination were done for the comparison of grafted materials in sinus cavity between groups. At 4 months after sinus bone graft procedure, biopsy specimens were analyzed by microcomputed tomography and histomorphometric examination for the evaluation of healing state of bone graft site. RESULTS In CT evaluation, there was no difference in bone density, bone height and sinus membrane thickness between groups. In microCT analysis, there was no difference in total bone volume, new bone volume, bone mineral density of new bone between groups. There was significant difference trabecular thickness (0.07 µm in Bio-Oss group Vs. 0.08 µm in AutoBT group) (P=.006). In histomorphometric analysis, there was no difference in new bone formation, residual graft material, bone marrow space between groups. There was significant difference osteoid thickness (8.35 µm in Bio-Oss group Vs. 13.12 µm in AutoBT group) (P=.025). CONCLUSION AutoBT could be considered a viable alternative to the autogenous bone or other bone graft materials in sinus bone graft procedure. PMID:25551014

  5. Comparison of bone marrow aspiration cytology with bone marrow trephine biopsy histopathology: An observational study.

    PubMed

    Gilotra, Meenu; Gupta, Monika; Singh, Sunita; Sen, Rajeev

    2017-01-01

    Bone marrow examination is a useful investigative tool for the diagnosis of many hematological and nonhematological disorders. Bone marrow aspiration (BMA) provides information about the numerical and cytological features of marrow cells, whereas bone marrow trephine biopsies (BMB) provide excellent appreciation of spatial relationships between cells and of overall bone marrow structure. We conducted this study with the objective of comparing the accuracy of BMA with BMB in the diagnosis of various hematological disorders. Both BMA and BMB were performed on a total of 130 cases and a comparative evaluation was performed in 100 cases to see the complementary role of both the procedures. However, 30 cases were excluded due to inadequate BMA, BMB, or both. Immunohistochemistry (IHC) was employed whenever required. In our study of 100 cases, 87% of cases were confirmed on bone marrow biopsy and in remaining 13% of cases final diagnosis was achieved with the help of other ancillary investigations. These cases were excluded for calculation of concordance rate between BMA and BMB. The concordance and disconcordance rate between BMA and BMB was 72.4% and 27.6%, respectively. BMA cytology and trephine biopsy histopathology complement each other and the superiority of one method over the other depended on the underlying disorder. Furthermore, application of ancillary techniques such as flow cytometery and IHC proved to be an additional advantage in further typing of various diseases.

  6. Working-for-Food Behaviors: A Preclinical Study in Prader-Willi Mutant Mice

    PubMed Central

    Lassi, Glenda; Maggi, Silvia; Balzani, Edoardo; Cosentini, Ilaria; Garcia-Garcia, Celina; Tucci, Valter

    2016-01-01

    Abnormal feeding behavior is one of the main symptoms of Prader-Willi syndrome (PWS). By studying a PWS mouse mutant line, which carries a paternally inherited deletion of the small nucleolar RNA 116 (Snord116), we observed significant changes in working-for-food behavioral responses at various timescales. In particular, we report that PWS mutant mice show a significant delay compared to wild-type littermate controls in responding to both hour-scale and seconds-to-minutes-scale time intervals. This timing shift in mutant mice is associated with better performance in the working-for-food task, and results in better decision making in these mutant mice. The results of our study reveal a novel aspect of the organization of feeding behavior, and advance the understanding of the interplay between the metabolic functions and cognitive mechanisms of PWS. PMID:27672097

  7. Prazosin addition to fluvoxamine: A preclinical study and open clinical trial in OCD.

    PubMed

    Feenstra, Matthijs G P; Klompmakers, André; Figee, Martijn; Fluitman, Sjoerd; Vulink, Nienke; Westenberg, Herman G M; Denys, Damiaan

    2016-02-01

    The efficacy of selective serotonin reuptake inhibitors (SRIs) in psychiatric disorders may be "augmented" through the addition of atypical antipsychotic drugs. A synergistic increase in dopamine (DA) release in the prefrontal cortex has been suggested to underlie this augmentation effect, though the mechanism of action is not clear yet. We used in vivo microdialysis in rats to study DA release following the administration of combinations of fluvoxamine (10 mg/kg) and quetiapine (10 mg/kg) with various monoamine-related drugs. The results confirmed that the selective 5-HT1A antagonist WAY-100635 (0.05 mg/kg) partially blocked the fluvoxamine-quetiapine synergistic effect (maximum DA increase dropped from 325% to 214%). A novel finding is that the α1-adrenergic blocker prazosin (1 mg/kg), combined with fluvoxamine, partially mimicked the effect of augmentation (maximum DA increase 205%; area-under-the-curve 163%). As this suggested that prazosin augmentation might be tested in a clinical study, we performed an open clinical trial of prazosin 20 mg addition to SRI in therapy-resistant patients with obsessive-compulsive disorder applying for neurosurgery. A small, non-significant reduction in Yale Brown Obsessive Compulsive Scale (Y-BOCS) scores was observed in 10 patients and one patient was classified as a responder with a reduction in Y-BOCS scores of more than 25%. We suggest that future clinical studies augmenting SRIs with an α1-adrenergic blocker in less treatment resistant cases should be considered. The clinical trial "Prazosin in combination with a serotonin reuptake inhibitor for patients with Obsessive Compulsive disorder: an open label study" was registered at 24/05/2011 under trial number ISRCTN61562706: http://www.controlled-trials.com/ISRCTN61562706.

  8. Sulfur containing acridine derivatives in preclinical studies with cancer cell lines.

    PubMed

    Othman, Salem; Mária, Kožurková

    2017-04-14

    The possible use of acridines as anticancer agents was first considered in the 1920´s. Since then, a large number of acridine drugs have been tested as antitumour agents, including compounds containing sulphur on the acridine chromophore. In this review, we will discuss recent studies which have investigated the anticancer activity of this class of acridine derivatives. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. Validation of the Filovirus Plaque Assay for Use in Preclinical Studies

    PubMed Central

    Shurtleff, Amy C.; Bloomfield, Holly A.; Mort, Shannon; Orr, Steven A.; Audet, Brian; Whitaker, Thomas; Richards, Michelle J.; Bavari, Sina

    2016-01-01

    A plaque assay for quantitating filoviruses in virus stocks, prepared viral challenge inocula and samples from research animals has recently been fully characterized and standardized for use across multiple institutions performing Biosafety Level 4 (BSL-4) studies. After standardization studies were completed, Good Laboratory Practices (GLP)-compliant plaque assay method validation studies to demonstrate suitability for reliable and reproducible measurement of the Marburg Virus Angola (MARV) variant and Ebola Virus Kikwit (EBOV) variant commenced at the United States Army Medical Research Institute of Infectious Diseases (USAMRIID). The validation parameters tested included accuracy, precision, linearity, robustness, stability of the virus stocks and system suitability. The MARV and EBOV assays were confirmed to be accurate to ±0.5 log10 PFU/mL. Repeatability precision, intermediate precision and reproducibility precision were sufficient to return viral titers with a coefficient of variation (%CV) of ≤30%, deemed acceptable variation for a cell-based bioassay. Intraclass correlation statistical techniques for the evaluation of the assay’s precision when the same plaques were quantitated by two analysts returned values passing the acceptance criteria, indicating high agreement between analysts. The assay was shown to be accurate and specific when run on Nonhuman Primates (NHP) serum and plasma samples diluted in plaque assay medium, with negligible matrix effects. Virus stocks demonstrated stability for freeze-thaw cycles typical of normal usage during assay retests. The results demonstrated that the EBOV and MARV plaque assays are accurate, precise and robust for filovirus titration in samples associated with the performance of GLP animal model studies. PMID:27110807

  10. Induction of fully stabilized cortical bone defects to study intramembranous bone regeneration

    PubMed Central

    McGee-Lawrence, Meghan E.; Razidlo, David F.

    2015-01-01

    Summary Bone is a regenerative tissue with an innate ability to self-remodel in response to environmental stimuli and the need to repair damage. Rodent models of fracture healing, and in particular genetic mouse models, can be used to study the contributions of specific molecular switches to skeletal repair, as well as to recreate and exacerbate biological development and repair mechanisms in postnatal skeletons. Here, we describe methodology for producing fully stabilized, single-cortex defects in mouse femurs to study mechanisms of intramembranous bone regeneration. PMID:25331051

  11. Issues in pharmaceutical development of thymosin alpha1 from preclinical studies through marketing.

    PubMed

    Tuthill, Cynthia

    2007-09-01

    SciClone Pharmaceuticals licensed the commercial and patent rights to thymosin alpha1, for geographical regions of the world excluding the United States and Europe, in the early 1990s. With this license, SciClone embarked on global drug development, and the issues encountered for thymosin alpha1 are reflective of the roller coaster of modern approval of pharmaceuticals. Most of the required toxicology studies had been completed prior to licensure, but some newer studies had to be conducted to obtain approvals in certain countries. The recent development of the "International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use" (ICH) guidelines allows for a clearer definition of the required battery of toxicology studies, although some countries still have not adopted these guidelines, and the local regulations have had to be understood and followed. Other hurdles include the complications that manufacturing requirements can differ between countries, and certain countries require local clinical experience trials in addition to SciClone's cumulative clinical data. A further obstacle was the pleiotropic nature of the mechanism of action of thymosin alpha1, with the resulting difficulty in the unraveling of its pharmacologic effects. With close attention to these regulatory details, SciClone has obtained approvals in more than 30 countries and has successfully begun commercial sales.

  12. Preclinical Magnetic Resonance Imaging and Spectroscopy Studies of Memory, Aging, and Cognitive Decline

    PubMed Central

    Febo, Marcelo; Foster, Thomas C.

    2016-01-01

    Neuroimaging provides for non-invasive evaluation of brain structure and activity and has been employed to suggest possible mechanisms for cognitive aging in humans. However, these imaging procedures have limits in terms of defining cellular and molecular mechanisms. In contrast, investigations of cognitive aging in animal models have mostly utilized techniques that have offered insight on synaptic, cellular, genetic, and epigenetic mechanisms affecting memory. Studies employing magnetic resonance imaging and spectroscopy (MRI and MRS, respectively) in animal models have emerged as an integrative set of techniques bridging localized cellular/molecular phenomenon and broader in vivo neural network alterations. MRI methods are remarkably suited to longitudinal tracking of cognitive function over extended periods permitting examination of the trajectory of structural or activity related changes. Combined with molecular and electrophysiological tools to selectively drive activity within specific brain regions, recent studies have begun to unlock the meaning of fMRI signals in terms of the role of neural plasticity and types of neural activity that generate the signals. The techniques provide a unique opportunity to causally determine how memory-relevant synaptic activity is processed and how memories may be distributed or reconsolidated over time. The present review summarizes research employing animal MRI and MRS in the study of brain function, structure, and biochemistry, with a particular focus on age-related cognitive decline. PMID:27468264

  13. SU-F-R-01: Preclinical Radioimmunogenomics Study to Design Personalized Radiotherapy

    SciTech Connect

    Abdollahi, H

    2016-06-15

    Purpose: Radiogenomics is an active area of research to find clinical correlation between genomics and radiotherapy outcomes. In this era, many different biological issues should be taken into account. In this study we aimed to introduce “Radioimmunogenomics” as a new approach to study immunogetics issue regard to radiotherapy induced clinical manifestations. Methods: We studied different immunological pathways and signaling molecules which underling radiation response of normal and malignant tissues. In the other hand, we found many genes and proteins are responsible to radiation effects on biological tissues. We defined a theoretical framework to correlate these genes with radiotherapy outcomes as TCP and NTCP biological dose tools. Results: Our theoretical results showed, high-throughput immunogenomics biomarkers can be correlated with radiotherapy outcomes. Genes regarding to inflammation, apoptosis, repair molecules and many other immunological markers can be defined as radioimmune markers to predict radiotherapy response. Conclusion: Radioimmunogenomics can be used as a new personalized radiotherapy research area to enhance treatment outcome as well as quality of life.

  14. Management of long bone metastases: recommendations from the Italian Orthopaedic Society bone metastasis study group.

    PubMed

    Capanna, Rodolfo; Piccioli, Andrea; Di Martino, Alberto; Daolio, Primo Andrea; Ippolito, Vincenzo; Maccauro, Giulio; Piana, Raimondo; Ruggieri, Pietro; Gasbarrini, Alessandro; Spinelli, Maria Silvia; Campanacci, Domenico Andrea

    2014-10-01

    The purpose of this article is to outline the current approach to patients affected by metastasis to the long bones and to present a clinical and surgical algorithm available for clinicians and for future research. A modern approach to patients affected by long bone metastasis in fact requires a multidisciplinary contest where oncologists, radiotherapists, surgeons and physical therapists cooperate with a shared vision, in order to provide the best possible integrated treatments available. The authors of this article constitute the Bone Metastasis Study Group of the Italian Orthopaedic Society (SIOT): a national group of orthopedic tumor surgeons who are dedicated to studying the approach, techniques and outcomes of surgery for metastatic tumours of the musculoskeletal system.

  15. The Relationship between Risk of Bias Criteria, Research Outcomes, and Study Sponsorship in a Cohort of Preclinical Thiazolidinedione Animal Studies: A Meta-Analysis.

    PubMed

    Abdel-Sattar, Maher; Krauth, David; Anglemyer, Andrew; Bero, Lisa

    2014-04-01

    There is little evidence regarding the influence of conflicts of interest on preclinical research. This study examines whether industry sponsorship is associated with increased risks of bias and/or effect sizes of outcomes in published preclinical thiazolidinedione (TZD) studies. We identified preclinical TZD studies published between January 1, 1965 and November 14, 2012. Coders independently extracted information on study design criteria aimed at reducing bias, results for all relevant outcomes, sponsorship source, and investigator financial ties from the 112 studies meeting the inclusion criteria. The average standardized mean difference (SMD) across studies was calculated for plasma glucose (efficacy outcome) and weight gain (harm outcome). In subgroup analyses, TZD outcomes were assessed by sponsorship source and risk of bias criteria. Seven studies were funded by industry alone, 17 studies funded by both industry and non-industry, 49 studies funded by non-industry alone, and 39 studies had no disclosures. None of the studies used sample size calculations, intention-to-treat analyses, blinding of investigators, or concealment of allocation. Most studies reported favorable results (88 of 112) and conclusions (95 of 112) supporting TZD use. Efficacy estimates were significantly larger in 6 studies sponsored by industry alone (-3.41; 95% CI -5.21, -1.53; I(2) = 93%) versus 42 studies sponsored by non-industry sources (-0.97; 95% CI -1.37, -0.56; I(2) = 81%) (p value = 0.01). Harms estimates were significantly larger in 4 studies sponsored by industry alone (5.00; 95% CI 1.22, 8.77; I(2) = 93%) versus 38 studies sponsored by non-industry sources (0.30; 95% CI -0.08, 0.68; I(2) = 79%) (p value = 0.02). TZD efficacy and harms did not differ by disclosure of financial COIs or risks of bias. Industry-sponsored TZD animal studies have exaggerated efficacy and harms outcomes compared to studies funded by non-industry sources. There was poor reporting of COIs.

  16. Long-term drug administration in the adult zebrafish using oral gavage for cancer preclinical studies

    PubMed Central

    Dang, Michelle; Henderson, Rachel E.; Garraway, Levi A.

    2016-01-01

    ABSTRACT Zebrafish are a major model for chemical genetics, and most studies use embryos when investigating small molecules that cause interesting phenotypes or that can rescue disease models. Limited studies have dosed adults with small molecules by means of water-borne exposure or injection techniques. Challenges in the form of drug delivery-related trauma and anesthesia-related toxicity have excluded the adult zebrafish from long-term drug efficacy studies. Here, we introduce a novel anesthetic combination of MS-222 and isoflurane to an oral gavage technique for a non-toxic, non-invasive and long-term drug administration platform. As a proof of principle, we established drug efficacy of the FDA-approved BRAFV600E inhibitor, Vemurafenib, in adult zebrafish harboring BRAFV600E melanoma tumors. In the model, adult casper zebrafish intraperitoneally transplanted with a zebrafish melanoma cell line (ZMEL1) and exposed to daily sub-lethal dosing at 100 mg/kg of Vemurafenib for 2 weeks via oral gavage resulted in an average 65% decrease in tumor burden and a 15% mortality rate. In contrast, Vemurafenib-resistant ZMEL1 cell lines, generated in culture from low-dose drug exposure for 4 months, did not respond to the oral gavage treatment regimen. Similarly, this drug treatment regimen can be applied for treatment of primary melanoma tumors in the zebrafish. Taken together, we developed an effective long-term drug treatment system that will allow the adult zebrafish to be used to identify more effective anti-melanoma combination therapies and opens up possibilities for treating adult models of other diseases. PMID:27482819

  17. Dynamic Autologous Reendothelialization of Small-Caliber Arterial Extracellular Matrix: A Preclinical Large Animal Study

    PubMed Central

    Dahan, Nitsan; Sarig, Udi; Bronshtein, Tomer; Baruch, Limor; Karram, Tony; Hoffman, Aaron

    2017-01-01

    Effective cellularization is a key approach to prevent small-caliber (<4 mm) tissue-engineered vascular graft (TEVG) failure and maintain patency and contractility following implantation. To achieve this goal, however, improved biomimicking designs and/or relatively long production times (typically several months) are required. We previously reported on porcine carotid artery decellularization yielding biomechanically stable and cell supportive small-caliber (3–4 mm diameter, 5 cm long) arterial extracellular matrix (scaECM) vascular grafts. In this study, we aimed to study the scaECM graft patency in vivo and possibly improve that patency by graft pre-endothelialization with the recipient porcine autologous cells using our previously reported custom-designed dynamic perfusion bioreactor system. Decellularized scaECM vascular grafts were histologically characterized, their immunoreactivity studied in vitro, and their biocompatibility profile evaluated as a xenograft subcutaneous implantation in a mouse model. To study the scaECM cell support and remodeling ability, pig autologous endothelial and smooth muscle cells (SMCs) were seeded and dynamically cultivated within the scaECM lumen and externa/media, respectively. Finally, endothelialized-only scaECMs—hypothesized as a prerequisite for maintaining graft patency and controlling intimal hyperplasia—were transplanted as an interposition carotid artery graft in a porcine model. Graft patency was evaluated through angiography online and endpoint pathological assessment for up to 6 weeks. Our results demonstrate the scaECM-TEVG biocompatibility preserving a structurally and mechanically stable vascular wall not just following decellularization and recellularization but also after implantation. Using our dynamic perfusion bioreactor, we successfully demonstrated the ability of this TEVG to support in vitro recellularization and remodeling by primary autologous endothelial and SMCs, which were seeded on the

  18. Preclinical Studies Evaluating Subacute Toxicity and Therapeutic Efficacy of LQB-118 in Experimental Visceral Leishmaniasis

    PubMed Central

    Cunha-Júnior, Edézio Ferreira; Martins, Thiago Martino; Canto-Cavalheiro, Marilene Marcuzzo; Marques, Paulo Roberto; Portari, Elyzabeth Avvad; Coelho, Marsen Garcia Pinto; Netto, Chaquip Daher; Costa, Paulo Roberto Ribeiro; Sabino, Katia Costa de Carvalho

    2016-01-01

    Visceral leishmaniasis (VL) is the most severe form of leishmaniasis and is the second major cause of death by parasites, after malaria. The arsenal of drugs against leishmaniasis is small, and each has a disadvantage in terms of toxicity, efficacy, price, or treatment regimen. Our group has focused on studying new drug candidates as alternatives to current treatments. The pterocarpanquinone LQB-118 was designed and synthesized based on molecular hybridization, and it exhibited antiprotozoal and anti-leukemic cell line activities. Our previous work demonstrated that LQB-118 was an effective treatment for experimental cutaneous leishmaniasis. In this study, we observed that treatment with 10 mg/kg of body weight/day LQB-118 orally inhibited the development of hepatosplenomegaly with a 99% reduction in parasite load. An in vivo toxicological analysis showed no change in the clinical, biochemical, or hematological parameters. Histologically, all of the analyzed organs were normal, with the exception of the liver, where focal points of necrosis with leukocytic infiltration were observed at treatment doses 5 times higher than the therapeutic dose; however, these changes were not accompanied by an increase in transaminases. Our findings indicate that LQB-118 is effective at treating different clinical forms of leishmaniasis and presents no relevant signs of toxicity at therapeutic doses; thus, this framework is demonstrated suitable for developing promising drug candidates for the oral treatment of leishmaniasis. PMID:27067332

  19. Masitinib Antagonizes ATP-Binding Cassette Subfamily C Member 10-Mediated Paclitaxel Resistance: A Preclinical Study

    PubMed Central

    Kathawala, Rishil J.; Sodani, Kamlesh; Chen, Kang; Patel, Atish; Abuznait, Alaa H.; Anreddy, Nagaraju; Sun, Yue-Li; Kaddoumi, Amal; Ashby, Charles R.; Chen, Zhe-Sheng

    2014-01-01

    Paclitaxel displays clinical activity against a wide variety of solid tumors. However, resistance to paclitaxel significantly attenuates the response to chemotherapy. The ABC transporter subfamily C member 10 (ABCC10), also known as multi-drug resistance protein 7 (MRP7) efflux transporter, is a major mediator of paclitaxel resistance. In this study, we show that masitinib, a small molecule stem-cell growth factor receptor (c-Kit) tyrosine kinase inhibitor, at non-toxic concentrations, significantly attenuates paclitaxel resistance in HEK293 cells transfected with ABCC10. Our in vitro studies indicated that masitinib (2.5 μM) enhanced the intracellular accumulation and decreased the efflux of paclitaxel by inhibiting the ABCC10 transport activity without altering the expression level of ABCC10 protein. Furthermore, masitinib, in combination with paclitaxel, significantly inhibited the growth of ABCC10-expressing tumors in nude athymic mice in vivo. Masitinib administration also resulted in a significant increase in the levels of paclitaxel in the plasma, tumors and lungs compared to paclitaxel alone. In conclusion, the combination of paclitaxel and masitinib could serve as a novel and useful therapeutic strategy to reverse paclitaxel resistance mediated by ABCC10. PMID:24431074

  20. Preclinical Studies Evaluating Subacute Toxicity and Therapeutic Efficacy of LQB-118 in Experimental Visceral Leishmaniasis.

    PubMed

    Cunha-Júnior, Edézio Ferreira; Martins, Thiago Martino; Canto-Cavalheiro, Marilene Marcuzzo; Marques, Paulo Roberto; Portari, Elyzabeth Avvad; Coelho, Marsen Garcia Pinto; Netto, Chaquip Daher; Costa, Paulo Roberto Ribeiro; Sabino, Katia Costa de Carvalho; Torres-Santos, Eduardo Caio

    2016-06-01

    Visceral leishmaniasis (VL) is the most severe form of leishmaniasis and is the second major cause of death by parasites, after malaria. The arsenal of drugs against leishmaniasis is small, and each has a disadvantage in terms of toxicity, efficacy, price, or treatment regimen. Our group has focused on studying new drug candidates as alternatives to current treatments. The pterocarpanquinone LQB-118 was designed and synthesized based on molecular hybridization, and it exhibited antiprotozoal and anti-leukemic cell line activities. Our previous work demonstrated that LQB-118 was an effective treatment for experimental cutaneous leishmaniasis. In this study, we observed that treatment with 10 mg/kg of body weight/day LQB-118 orally inhibited the development of hepatosplenomegaly with a 99% reduction in parasite load. An in vivo toxicological analysis showed no change in the clinical, biochemical, or hematological parameters. Histologically, all of the analyzed organs were normal, with the exception of the liver, where focal points of necrosis with leukocytic infiltration were observed at treatment doses 5 times higher than the therapeutic dose; however, these changes were not accompanied by an increase in transaminases. Our findings indicate that LQB-118 is effective at treating different clinical forms of leishmaniasis and presents no relevant signs of toxicity at therapeutic doses; thus, this framework is demonstrated suitable for developing promising drug candidates for the oral treatment of leishmaniasis.

  1. Evaluation of wound healing activity of Lantana camara L. - a preclinical study.

    PubMed

    Nayak, B Shivananda; Raju, S Sivachandra; Eversley, Mathew; Ramsubhag, Adash

    2009-02-01

    Lantana camara is used in herbal medicine for the treatment of skin itches, as an antiseptic for wounds, and externally for leprosy and scabies. The objective of our study was to investigate excision wound healing activity of the leaf extract of L. camara in rats. The animals were divided into two groups of 12 each in both the models. The test group animals were treated with the aqueous extract of L. camara (100 mg/kg/day) topically and the control group animals were left untreated. Wound healing efficacy was measured by determining the morphological and biochemical parameters. Wound healing time, wound contraction and synthesis of collagen were monitored periodically. Antimicrobial activities of the extract against the microorganisms were also assessed. Treatment of the wounds with extract enhanced significantly the rate of wound contraction (98%), synthesis of collagen and decreased mean wound healing time. These studies demonstrate that L. camara is effective in healing excision wounds in the experimental animal and could be evaluated as a therapeutic agent in tissue repair processes associated with skin injuries.

  2. Quality of Reporting and Adherence to ARRIVE Guidelines in Animal Studies for Chagas Disease Preclinical Drug Research: A Systematic Review.

    PubMed

    Gulin, Julián Ernesto Nicolás; Rocco, Daniela Marisa; García-Bournissen, Facundo

    2015-11-01

    Publication of accurate and detailed descriptions of methods in research articles involving animals is essential for health scientists to accurately interpret published data, evaluate results and replicate findings. Inadequate reporting of key aspects of experimental design may reduce the impact of studies and could act as a barrier to translation of research findings. Reporting of animal use must be as comprehensive as possible in order to take advantage of every study and every animal used. Animal models are essential to understanding and assessing new chemotherapy candidates for Chagas disease pathology, a widespread parasitic disease with few treatment options currently available. A systematic review was carried out to compare ARRIVE guidelines recommendations with information provided in publications of preclinical studies for new anti-Trypanosoma cruzi compounds. A total of 83 publications were reviewed. Before ARRIVE guidelines, 69% of publications failed to report any macroenvironment information, compared to 57% after ARRIVE publication. Similar proportions were observed when evaluating reporting of microenvironmental information (56% vs. 61%). Also, before ARRIVE guidelines publication, only 13% of papers described animal gender, only 18% specified microbiological status and 13% reported randomized treatment assignment, among other essential information missing or incomplete. Unfortunately, publication of ARRIVE guidelines did not seem to enhance reporting quality, compared to papers appeared before ARRIVE publication. Our results suggest that there is a strong need for the scientific community to improve animal use description, animal models employed, transparent reporting and experiment design to facilitate its transfer and application to the affected human population. Full compliance with ARRIVE guidelines, or similar animal research reporting guidelines, would be an excellent start in this direction.

  3. Delayed-Release Dimethyl Fumarate and Pregnancy: Preclinical Studies and Pregnancy Outcomes from Clinical Trials and Postmarketing Experience.

    PubMed

    Gold, Ralf; Phillips, J Theodore; Havrdova, Eva; Bar-Or, Amit; Kappos, Ludwig; Kim, Norman; Thullen, Tim; Valencia, Patricia; Oliva, Lauren; Novas, Mark; Li, Jie; Sweetser, Marianne T; Kurukulasuriya, Nuwan; Viglietta, Vissia; Fox, Robert J

    2015-12-01

    Delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) is an oral agent for the treatment of relapsing forms of multiple sclerosis (MS). No formal studies of DMF were conducted in pregnant women, although pregnancies have occurred during clinical trials and in the postmarketing setting. Preclinical developmental and reproductive toxicology studies were performed with DMF in rats and rabbits. As of March 26, 2014, the DMF clinical development program included a total of 4132 subjects consisting of 2898 patients with MS, 320 psoriasis patients, 101 rheumatoid arthritis patients, and 813 healthy volunteers. Subjects were required to use reliable contraception and immediately discontinue treatment in the event of pregnancy. Animal studies showed no evidence of impaired fertility or teratogenicity with DMF. Overall as of June 30, 2014, 63 pregnancies were reported in clinical trials. Outcomes are known for 39 of 42 subjects receiving DMF and include 26 live births (67%), three spontaneous abortions (8%), and 10 elective terminations (26%); follow-up is ongoing in 2 cases and one patient was lost to follow-up. The incidence of spontaneous abortion in subjects exposed to DMF was consistent with the expected rate of early pregnancy loss in the general population (12-22%). A total of 135 pregnancies were reported in the postmarketing setting (spontaneous and solicited reports). Outcomes are known for 30 cases and include 10 live births, 13 spontaneous abortions, and 5 elective terminations; follow-up is ongoing in 103 cases and 2 patients have been lost to follow-up. Although data are limited and all known exposures have occurred in the first trimester, no increased risk of fetal abnormalities or adverse pregnancy outcomes associated with gestational exposure to DMF has been observed. Biogen, Inc.

  4. Quality of Reporting and Adherence to ARRIVE Guidelines in Animal Studies for Chagas Disease Preclinical Drug Research: A Systematic Review

    PubMed Central

    Gulin, Julián Ernesto Nicolás; Rocco, Daniela Marisa; García-Bournissen, Facundo

    2015-01-01

    Publication of accurate and detailed descriptions of methods in research articles involving animals is essential for health scientists to accurately interpret published data, evaluate results and replicate findings. Inadequate reporting of key aspects of experimental design may reduce the impact of studies and could act as a barrier to translation of research findings. Reporting of animal use must be as comprehensive as possible in order to take advantage of every study and every animal used. Animal models are essential to understanding and assessing new chemotherapy candidates for Chagas disease pathology, a widespread parasitic disease with few treatment options currently available. A systematic review was carried out to compare ARRIVE guidelines recommendations with information provided in publications of preclinical studies for new anti-Trypanosoma cruzi compounds. A total of 83 publications were reviewed. Before ARRIVE guidelines, 69% of publications failed to report any macroenvironment information, compared to 57% after ARRIVE publication. Similar proportions were observed when evaluating reporting of microenvironmental information (56% vs. 61%). Also, before ARRIVE guidelines publication, only 13% of papers described animal gender, only 18% specified microbiological status and 13% reported randomized treatment assignment, among other essential information missing or incomplete. Unfortunately, publication of ARRIVE guidelines did not seem to enhance reporting quality, compared to papers appeared before ARRIVE publication. Our results suggest that there is a strong need for the scientific community to improve animal use description, animal models employed, transparent reporting and experiment design to facilitate its transfer and application to the affected human population. Full compliance with ARRIVE guidelines, or similar animal research reporting guidelines, would be an excellent start in this direction. PMID:26587586

  5. Influence of Teaching Strategies and its Order of Exposure on Pre-Clinical Teeth Arrangement – A Pilot Study

    PubMed Central

    Mani, Uma Maheswari; Christian, Jayanth; Seenivasan, Madhan Kumar; Natarajan, Parthasarathy; Vaidhyanathan, Anand Kumar

    2016-01-01

    Introduction Teeth arrangement is a vital skill for the undergraduate dental student. The attainment of skills depends largely on the methodology of teaching. In a dental curriculum, the students are exposed to a wide variety of inputs and teaching methodologies from different sources. The educational unit in dental school must identify the sequence of teaching methods that enhance the learning and practising ability of students. Aim The aim of this study was to evaluate the effectiveness of three different teaching methodologies for teeth arrangement and compare the differences between the orders of exposure to each teaching methodology on the development of teeth arrangement skills. Materials and Methods The first year B.D.S students were study participants and were divided into three groups A, B, C. They were exposed to three teaching patterns namely live demonstration with video assisted teaching, group discussion with hand-outs and lectures with power point presentation. After each teaching methodology, their skill was assessed. The groups were exposed to three methodologies in different order for three arrangements. The scores obtained were analysed using Kruskal Wallis rank sum test and Dunn test for statistical significance. Results Significantly higher scores in the teeth arrangement procedure were obtained by the Group A students who were exposed initially to live demonstration with video-assisted teaching. Difference in the scores was noted among and within the groups. The difference between Group A and Group C was statistically significant after both first and third teeth arrangement (p=0.0031, p=0.0057). Conclusion The study suggests each pre-clinical practice should begin with a live demonstration to enhance immediate learning absorption followed by lectures with power point presentation and group discussion for retention of knowledge and memory retrieval. PMID:27891468

  6. Influence of Teaching Strategies and its Order of Exposure on Pre-Clinical Teeth Arrangement - A Pilot Study.

    PubMed

    Jeyapalan, Karthigeyan; Mani, Uma Maheswari; Christian, Jayanth; Seenivasan, Madhan Kumar; Natarajan, Parthasarathy; Vaidhyanathan, Anand Kumar

    2016-10-01

    Teeth arrangement is a vital skill for the undergraduate dental student. The attainment of skills depends largely on the methodology of teaching. In a dental curriculum, the students are exposed to a wide variety of inputs and teaching methodologies from different sources. The educational unit in dental school must identify the sequence of teaching methods that enhance the learning and practising ability of students. The aim of this study was to evaluate the effectiveness of three different teaching methodologies for teeth arrangement and compare the differences between the orders of exposure to each teaching methodology on the development of teeth arrangement skills. The first year B.D.S students were study participants and were divided into three groups A, B, C. They were exposed to three teaching patterns namely live demonstration with video assisted teaching, group discussion with hand-outs and lectures with power point presentation. After each teaching methodology, their skill was assessed. The groups were exposed to three methodologies in different order for three arrangements. The scores obtained were analysed using Kruskal Wallis rank sum test and Dunn test for statistical significance. Significantly higher scores in the teeth arrangement procedure were obtained by the Group A students who were exposed initially to live demonstration with video-assisted teaching. Difference in the scores was noted among and within the groups. The difference between Group A and Group C was statistically significant after both first and third teeth arrangement (p=0.0031, p=0.0057). The study suggests each pre-clinical practice should begin with a live demonstration to enhance immediate learning absorption followed by lectures with power point presentation and group discussion for retention of knowledge and memory retrieval.

  7. Preclinical studies on the reinforcing effects of cannabinoids. A tribute to the scientific research of Dr. Steve Goldberg

    PubMed Central

    Tanda, Gianluigi

    2016-01-01

    Rationale The reinforcing effects of most abused drugs have been consistently demonstrated and studied in animal models, although those of marijuana were not, until the demonstration fifteen years ago that THC could serve as a reinforcer in self-administration (SA) procedures in squirrel monkeys. Until then, those effects were inferred using indirect assessments. Objectives The aim of this manuscript is to review the primary preclinical procedures used to indirectly and directly infer reinforcing effects of cannabinoid drugs. Methods Results will be reviewed from studies of cannabinoid-discrimination, intracranial-self-stimulation (ICSS), conditioned place preference (CPP), as well as change in levels of dopamine assessed in brain areas related to reinforcement, and finally from self-administration procedures. For each procedure, an evaluation will be made of the predictive validity in detecting the potential abuse liability of cannabinoids based on seminal papers, with the addition of selected reports from more recent years especially those from Dr. Goldberg’s research group. Results and Conclusions ICSS and CPP do not provide consistent results for the assessment of potential for abuse of cannabinoids. However, drug-discrimination and neurochemistry procedures appear to detect potential for abuse of cannabinoids, as well as several novel “designer cannabinoid drugs.” Though after 15 years it remains somewhat problematic transfer the self-administration model of marijuana abuse from squirrel monkeys to other species, studies with the former species have substantially advanced the field, and several reports have been published with consistent self-administration of cannabinoid agonists in rodents. PMID:27026633

  8. Preclinical Studies on Mesenchymal Stem Cell-Based Therapy for Growth Plate Cartilage Injury Repair

    PubMed Central

    Chung, Rosa; Foster, Bruce K.; Xian, Cory J.

    2011-01-01

    In the last two decades, there has been a strong interest in searching for biological treatments for regeneration of injured growth plate cartilage and prevention of its bony repair. Various means have been tried, including implantation of chondrocytes, mesenchymal stem cell (MSC), together with exogenous growth factor and scaffolds, and gene therapy. However, with the lack of success with chondrocytes, more research has focussed on MSC-based treatments. In addition to circumvent limitations with MSC-based treatments (including cell harvest-associated morbidity, difficulties/time/cost involved in MSC isolation and ex vivo expansion, and potential disease transmission), mobilising endogenous MSCs to the growth plate injury site and enhancing in situ regeneration mechanisms would represent an alternative attractive approach. Further studies are required to investigate the potential particularly in large animal models or clinical setting of the ex vivo MSC approach and the feasibility of the endogenous MSC in situ approach in growth plate regeneration. PMID:21808649

  9. Systematic Approach to Remediation in Basic Science Knowledge for Preclinical Students: A case study

    NASA Astrophysics Data System (ADS)

    Amara, Francis

    Remediation of pre-clerkship students for deficits in basic science knowledge should help them overcome their learning deficiencies prior to clerkship. However, very little is known about remediation in basic science knowledge during pre-clerkship. This study utilized the program theory framework to collect and organize mixed methods data of the remediation plan for pre-clerkship students who failed their basic science cognitive examinations in a Canadian medical school. This plan was analyzed using a logic model narrative approach and compared to literature on the learning theories. The analysis showed a remediation plan that was strong on governance and verification of scores, but lacked: clarity and transparency of communication, qualified remedial tutors, individualized diagnosis of learner's deficits, and student centered learning. Participants admitted uncertainty about the efficacy of the remediation process. A remediation framework is proposed that includes student-centered participation, individualized learning plan and activities, deliberate practice, feedback, reflection, and rigorous reassessment.

  10. Treating the Developing versus Developed Brain: Translating Preclinical Mouse and Human Studies

    PubMed Central

    Casey, BJ; Glatt, Charles E.; Lee, Francis S.

    2015-01-01

    Summary Behaviors and underlying brain circuits show characteristic changes across the life-span that produce sensitive windows of vulnerability and resilience to psychopathology. Understanding the developmental course of these changes may inform which treatments are best at what ages. Focusing on behavioral domains and neurobiological substrates conserved from mouse to human supports reciprocal hypothesis generation and testing that leverages the strengths of each system in understanding their development. Introducing human genetic variants into mice can further define effects of individual variation on normative development, how they contribute to risk and resilience for mental illness, and inform personalized treatment opportunities. This article emphasizes the period of adolescence, when there is a peak in the emergence of mental illness, in particular, anxiety disorders. We present cross-species studies relating fear learning to anxiety across development, and discuss how clinical treatments can be optimized for individuals and targeted to the biological states of the developing brain. PMID:26087163

  11. A feasibility study of soft embalmed human breast tissue for preclinical trials of HIFU- preliminary results

    NASA Astrophysics Data System (ADS)

    Joy, Joyce; Yang, Yang; Purdie, Colin; Eisma, Roos; Melzer, Andreas; Cochran, Sandy; Vinnicombe, Sarah

    2017-03-01

    Breast cancer is the commonest cancer in women in the UK, accounting for 30% of all new cancers in women, with an estimated 49,500 new cases in 20101. With the widespread negative publicity around over-diagnosis and over-treatment of low risk breast cancers, interest in the application of non-invasive treatments such as magnetic resonance imaging (MRI) guided high intensity focused ultrasound (HIFU) has increased. Development has begun of novel US transducers and platforms specifically designed for use with breast lesions, so as to improve the range of breast lesions that can be safely treated. However, before such transducers can be evaluated in patients in clinical trials, there is a need to establish their efficacy. A particular issue is the accuracy of temperature monitoring of FUS with MRI in the breast, since the presence of large amounts of surrounding fat can hinder temperature measurement. An appropriate anatomical model that imposes similar physical constraints to the breast and that responds to FUS in the same way would be extremely advantageous. The aim of this feasibility study is to explore the use of Thiel embalmed cadaveric tissue for these purposes. We report here the early results of laboratory-based experiments sonicating dissected breast samples from a Thiel embalmed soft human cadaver with high body mass index (BMI). A specially developed MRI compatible chamber and sample holder was developed to secure the sample and ensure reproducible sonications at the transducer focus. The efficacy of sonication was first studied with chicken breast and porcine tissue. The experiments were then repeated with the dissected fatty breast tissue samples from the soft-embalmed human cadavers. The sonicated Thiel breast tissue was examined histopathologically, which confirmed the absence of any discrete lesion. To investigate further, fresh chicken breast tissue was embalmed and the embalmed tissue was sonicated with the same parameters. The results confirmed the

  12. Physiology and Endocrinology Symposium: FGF21: Insights into mechanism of action from preclinical studies.

    PubMed

    Antonellis, P J; Kharitonenkov, A; Adams, A C

    2014-02-01

    Fibroblast growth factor 21 (FGF21) is a multifaceted metabolic regulator which has several potential applications in the treatment of metabolic disease. When administered in vivo, FGF21 exhibits a plethora of actions, modulating metabolic homeostasis in a diverse manner. However, the mechanism and site of action underlying these effects were, until recently, entirely uncertain. Using mouse models lacking either FGF receptor isoform 1 (FGFR1) or βKlotho (KLB), a transmembrane co-factor critical for FGF21 action, our group and others sought to determine the tissue on which FGF21 acts and the receptor complex responsible for mediating its in vivo efficacy. Importantly, when KLB was ablated from all tissues mice were completely refractory to FGF21 action. Therefore, to determine the precise tissue of action we utilized mice with tissue specific deletion of FGFR1 in either adipose tissue or neurons, respectively. Surprisingly, in animals with neuronal FGFR1 loss there was no change in the metabolic activity of FGF21, suggesting a lack of central FGF21 action in the pharmacologic setting. In contrast, we found dramatic attenuation of metabolic efficacy in mice with adipose-specific FGFR1 ablation following either acute or chronic dosing with recombinant FGF21. Furthermore, several recent studies have suggested that the metabolic effects of FGF21 may occur via modulation of adipokines such as adiponectin and leptin. Importantly, the action of FGF21 via adipose tissue results in alterations in both secretion as well as systemic sensitivity to these factors. Therefore, while FGF21 itself does not seem to directly act on the CNS, leptin and other endocrine mediators may serve as intermediary facilitators of FGF21's secondary central effects downstream of an initial and direct engagement of FGF21 receptor complex in adipose tissue. Further studies are required to delineate the precise mechanistic basis underlying the interplay between peripheral and central FGF21 modes of

  13. A Preclinical Study of Laryngeal Motor-Evoked Potentials as a Marker Vagus Nerve Activation.

    PubMed

    Grimonprez, Annelies; Raedt, Robrecht; De Taeye, Leen; Larsen, Lars Emil; Delbeke, Jean; Boon, Paul; Vonck, Kristl

    2015-12-01

    Vagus nerve stimulation (VNS) is a treatment for refractory epilepsy and depression. Previous studies using invasive recording electrodes showed that VNS induces laryngeal motor-evoked potentials (LMEPs) through the co-activation of the recurrent laryngeal nerve and subsequent contractions of the laryngeal muscles. The present study investigates the feasibility of recording LMEPs in chronically VNS-implanted rats, using a minimally-invasive technique, to assess effective current delivery to the nerve and to determine optimal VNS output currents for vagal fiber activation. Three weeks after VNS electrode implantation, signals were recorded using an electromyography (EMG) electrode in the proximity of the laryngeal muscles and a reference electrode on the skull. The VNS output current was gradually ramped up from 0.1 to 1.0 mA in 0.1 mA steps. In 13/27 rats, typical LMEPs were recorded at low VNS output currents (median 0.3 mA, IQR 0.2-0.3 mA). In 11/27 rats, significantly higher output currents were required to evoke electrophysiological responses (median 0.7 mA, IQR 0.5-0.7 mA, p < 0.001). The latencies of these responses deviated significantly from LMEPs (p < 0.05). In 3/27 rats, no electrophysiological responses to simulation were recorded. Minimally invasive LMEP recordings are feasible to assess effective current delivery to the vagus nerve. Furthermore, our results suggest that low output currents are sufficient to activate vagal fibers.

  14. Irinotecan delivery by microbubble-assisted ultrasound - A pilot preclinical study

    NASA Astrophysics Data System (ADS)

    Escoffre, Jean-Michel; Novell, Anthony; Serrière, Sophie; Bouakaz, Ayache

    2012-11-01

    Irinotecan is conventionally used for the treatment of colorectal cancer. However, its administration is associated with severe side effects. Targeted drug delivery using ultrasound (US) combined with microbubbles offers new opportunities to increase the therapeutic effectiveness of antitumor treatment and to reduce toxic exposure to healthy tissues. The objective of this study is to investigate the safety and efficacy of in-vivo delivery of irinotecan by microbubble-assisted US in human glioblastoma model (U-87 MG). In order to validate the potential of this new method in-vivo, subcutaneous tumors were implanted in the flank of nude mouse and treated when they reached a volume of 100 mm3. In the first study, the measured volumes with caliper and anatomic ultrasound imaging were compared for the monitoring and the quantification of tumor growth during 27 days. Ultrasound imaging measurements were positively correlated to caliper measurements. The tumor treatment consisted of an i.v. injection of irinotecan (20 mg/kg) followed one hour later by i.v. administration of MM1 microbubble and an US insonation using a single-element transducer operating at 1MHz (400 kPa, 10 kHz PRF 40% DC, 3 min). The therapeutic efficacy was evaluated for 39 days by measuring the tumor volume before and after treatment using a caliper and based on ultrasound images using an 18 MHz probe (Vevo 2100). Our results showed that anatomical ultrasound imaging was as efficient as caliper for the monitoring and the quantification of tumor growth. Moreover, irinotecan delivery by sonoporation induced a significant decrease of glioblastoma tumor volume and an increase of tumor-doubling time compared to the tumor treated by irinotecan alone. In conclusion, this novel therapeutic approach has promising features since it can be used to reduce the injected drug dose and to achieve a better therapeutic efficacy.

  15. A Selective Nociceptin Receptor Antagonist to Treat Depression: Evidence from Preclinical and Clinical Studies.

    PubMed

    Post, Anke; Smart, Trevor S; Krikke-Workel, Judith; Dawson, Gerard R; Harmer, Catherine J; Browning, Michael; Jackson, Kimberley; Kakar, Rishi; Mohs, Richard; Statnick, Michael; Wafford, Keith; McCarthy, Andrew; Barth, Vanessa; Witkin, Jeffrey M

    2016-06-01

    Nociceptin/Orphanin FQ (N/OFQ) is an endogenous ligand of the N/OFQ peptide (NOP) receptor, which is a G protein-coupled receptor in brain regions associated with mood disorders. We used a novel, potent, and selective orally bioavailable antagonist, LY2940094, to test the hypothesis that blockade of NOP receptors would induce antidepressant effects. In this study we demonstrate that targeting NOP receptors with LY2940094 translates to antidepressant-like effects in rodent models and, importantly, to antidepressant efficacy in patients with major depressive disorder (MDD). The proof-of-concept study (POC) was an 8-week, double-blind, placebo-controlled trial that evaluated LY2940094 as a novel oral medication for the treatment of patients with MDD. Once daily oral dosing of LY2940094 at 40 mg for 8 weeks vs placebo provided some evidence for an antidepressant effect based on the change from baseline to week 8 in the GRID-Hamilton Depression Rating Scale-17 item total score, although the predefined POC efficacy criterion (probability of LY2940094 being better than placebo⩾88%) was not met (82.9%). LY2940094 also had an early effect on the processing of emotional stimuli at Week 1 as shown by an increased recognition of positive relative to negative facial expressions in an emotional test battery. LY2940094 was safe and well tolerated. Overall, these are the first human data providing evidence that the blockade of NOP receptor signaling represents a promising strategy for the treatment of MDD.

  16. A Selective Nociceptin Receptor Antagonist to Treat Depression: Evidence from Preclinical and Clinical Studies

    PubMed Central

    Post, Anke; Smart, Trevor S; Krikke-Workel, Judith; Dawson, Gerard R; Harmer, Catherine J; Browning, Michael; Jackson, Kimberley; Kakar, Rishi; Mohs, Richard; Statnick, Michael; Wafford, Keith; McCarthy, Andrew; Barth, Vanessa; Witkin, Jeffrey M

    2016-01-01

    Nociceptin/Orphanin FQ (N/OFQ) is an endogenous ligand of the N/OFQ peptide (NOP) receptor, which is a G protein-coupled receptor in brain regions associated with mood disorders. We used a novel, potent, and selective orally bioavailable antagonist, LY2940094, to test the hypothesis that blockade of NOP receptors would induce antidepressant effects. In this study we demonstrate that targeting NOP receptors with LY2940094 translates to antidepressant-like effects in rodent models and, importantly, to antidepressant efficacy in patients with major depressive disorder (MDD). The proof-of-concept study (POC) was an 8-week, double-blind, placebo-controlled trial that evaluated LY2940094 as a novel oral medication for the treatment of patients with MDD. Once daily oral dosing of LY2940094 at 40 mg for 8 weeks vs placebo provided some evidence for an antidepressant effect based on the change from baseline to week 8 in the GRID-Hamilton Depression Rating Scale-17 item total score, although the predefined POC efficacy criterion (probability of LY2940094 being better than placebo⩾88%) was not met (82.9%). LY2940094 also had an early effect on the processing of emotional stimuli at Week 1 as shown by an increased recognition of positive relative to negative facial expressions in an emotional test battery. LY2940094 was safe and well tolerated. Overall, these are the first human data providing evidence that the blockade of NOP receptor signaling represents a promising strategy for the treatment of MDD. PMID:26585287

  17. Synthesis, characterization and preclinical studies of two-photon-activated targeted PDT therapeutic triads

    NASA Astrophysics Data System (ADS)

    Spangler, C. W.; Starkey, J. R.; Rebane, A.; Meng, F.; Gong, A.; Drobizhev, M.

    2006-02-01

    Photodynamic therapy (PDT) continues to evolve into a mature clinical treatment of a variety of cancer types as well as age-related macular degeneration of the eye. However, there are still aspects of PDT that need to be improved in order for greater clinical acceptance. While a number of new PDT photo-sensitizers, sometimes referred to as second- or third- generation therapeutic agents, are currently under clinical investigation, the direct treatment through the skin of subcutaneous tumors deeper than 5 mm remains problematic. Currently approved PDT porphyrin photo-sensitizers, as well as several modified porphyrins (e.g. chlorins, bacteriochlorins, etc.) that are under clinical investigation can be activated at 630-730 nm, but none above 800 nm. It would be highly desirable if new PDT paradigms could be developed that would allow photo-activation deep in the tissue transparency window in the Near-infrared (NIR) above 800 nm to reduce scattering and absorption phenomena that reduce deep tissue PDT efficacy. Rasiris and MPA Technologies have developed new porphyrins that have greatly enhanced two-photon absorption ( P A ) cross-sections and can be activated deep in the NIR (ca. 780-850 nm). These porphyrins can be incorporated into a therapeutic triad that also employs an small molecule targeting agent that directs the triad to over-expressed tumor receptor sites, and a NIR onephoton imaging agent that allows tracking the delivery of the triad to the tumor site, as well as clearance of excess triad from healthy tissue prior to the start of PDT treatment. We are currently using these new triads in efficacy studies with a breast cancer cell line that has been transfected with luciferase genes that allow implanted tumor growth and post- PDT treatment efficacy studies in SCID mouse models by following the rise and decay of the bioluminescence signal. We have also designed highly absorbing and scattering collagen breast cancer phantoms in which we have demonstrated

  18. [Experimental study of the thermic effect on bone at 60 degrees C, as applied to bone allograft].

    PubMed

    Le Huec, J C

    1992-01-01

    Bone reconstruction methods increasingly often require using bank bone. These massive bone fragments can be taken only from dead subjects or those in irreversible coma. Surgical sterility of the samples does not always guarantee the absence of an HIV infection, for which seroconversion often occurs very late. B. Spire's work has shown the effectiveness of a 30-minute heat treatment at 56 degrees C to inactivate HIV in blood products. Our study has therefore evaluated the effectiveness of a heat treatment method for bone to inactivate HIV on one hand, and the mechanical and histologic consequences of this treatment on rabbit bone. All bone fragments in this study were frozen at -80 degrees C to reproduce the same conditions of use as in current bone banks. Heating deep-frozen fragments of spongious tissue and of bone marrow from seropositive subjects in a 60 degrees C humid heat allowed confirming thermal sterilization of HIV, but a greater number of case is required to support this technique, as well as a verification with cortical bone. Thermal sterilization of bone allografts does not alter the mechanical properties nor the possibilities of bone regrowth in allografts. Application to human bone allografts should be confirmed by a greater number of cases, but it appears as a simple means to suppress the current disadvantage of late seroconversion control.

  19. Contributions of GABA to alcohol responsivity during adolescence: Insights from preclinical and clinical studies

    PubMed Central

    Silveri, Marisa M.

    2015-01-01

    There is a considerable body of literature demonstrating that adolescence is a unique age period, which includes rapid and dramatic maturation of behavioral, cognitive, hormonal and neurobiological systems. Most notably, adolescence is also a period of unique responsiveness to alcohol effects, with both hyposensitivity and hypersensitivity observed to the various effects of alcohol. Multiple neurotransmitter systems are undergoing fine-tuning during this critical period of brain development, including those that contribute to the rewarding effects of drugs of abuse. The role of developmental maturation of the γ-amino-butyric acid (GABA) system, however, has received less attention in contributing to age-specific alcohol sensitivities. This review integrates GABA findings from human magnetic resonance spectroscopy studies as they may translate to understanding adolescent-specific responsiveness to alcohol effects. Better understanding of the vulnerability of the GABA system both during adolescent development, and in psychiatric conditions that include alcohol dependence, could point to a putative mechanism, boosting brain GABA, that may have increased effectiveness for treating alcohol abuse disorders. PMID:24631274

  20. The usefulness of systematic reviews of animal experiments for the design of preclinical and clinical studies.

    PubMed

    de Vries, Rob B M; Wever, Kimberley E; Avey, Marc T; Stephens, Martin L; Sena, Emily S; Leenaars, Marlies

    2014-01-01

    The question of how animal studies should be designed, conducted, and analyzed remains underexposed in societal debates on animal experimentation. This is not only a scientific but also a moral question. After all, if animal experiments are not appropriately designed, conducted, and analyzed, the results produced are unlikely to be reliable and the animals have in effect been wasted. In this article, we focus on one particular method to address this moral question, namely systematic reviews of previously performed animal experiments. We discuss how the design, conduct, and analysis of future (animal and human) experiments may be optimized through such systematic reviews. In particular, we illustrate how these reviews can help improve the methodological quality of animal experiments, make the choice of an animal model and the translation of animal data to the clinic more evidence-based, and implement the 3Rs. Moreover, we discuss which measures are being taken and which need to be taken in the future to ensure that systematic reviews will actually contribute to optimizing experimental design and thereby to meeting a necessary condition for making the use of animals in these experiments justified.

  1. Wound healing activity of Persea americana (avocado) fruit: a preclinical study on rats.

    PubMed

    Nayak, B S; Raju, S S; Chalapathi Rao, A V

    2008-03-01

    Avocado (Persea americana) oil is rich in nutrient waxes, proteins and minerals, as well as vitamins A, D and E. It is an excellent source of enrichment for dry, damaged or chapped skin. This study aimed to evaluate the wound-healing activity of fruit extract of Persea americana in rats. The effect of topical and oral administration of Persea americana fruit extract (300 mg/kg/day) on excision and dead space wound models was evaluated. The rats used in the excision wound model were divided into four groups of five each and received either topical or oral treatment. The rats used in the dead space wound model were divided into two groups of five each and were treated orally. Healing was assessed by the rate of wound contraction, period of epithelialisation, granulation tissue weight and hydoxyproline content. In the excision wound model, complete healing (full epithelialisation) was observed on average on day 14 in the rats who receive oral or topical treatment. In contrast, the controls took approximately 17 days to heal completely. The extract-treated wounds were found to epithelialise faster than the controls (p < 0.001). Wet and dry granulation tissue weight and the hydroxyproline content of the tissue obtained from extract-treated animals used in the dead space wound model were significantly higher (p < 0.05) compared with the controls. Rate of wound contraction, epithelialisation time together with the hydroxyproline content and histological observations support the use of Persea americana in the management of wound healing.

  2. Silver nanoparticle/chitosan oligosaccharide/poly(vinyl alcohol) nanofibers as wound dressings: a preclinical study.

    PubMed

    Li, Chenwen; Fu, Ruoqiu; Yu, Caiping; Li, Zhuoheng; Guan, Haiyan; Hu, Daqiang; Zhao, Dehua; Lu, Laichun

    2013-01-01

    In this study, a mixture of poly(vinyl alcohol) (PVA) and chitosan oligosaccharides (COS) was electrospun with silver nanoparticles (AgNPs) to produce fibrous mats for use in wound healing. The AgNPs were reduced by COS prior to electrospinning or Ag(+) was reduced via ultraviolet irradiation in nanofibers. The morphologies of the PVA/COS/AgNO3 and PVA/COS-AgNP nanofibers were analyzed by scanning electron microscopy. Formation of the AgNPs was investigated by field emission transmission electron microscopy, ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. We also evaluated the biocompatibility of the nanofibers, particularly their cytotoxicity to human skin fibroblasts and potential to cause primary skin irritation. The in vitro antibacterial activity and in vivo wound healing capacity of the nanofibers were also investigated. The nanofibers had a smooth surface with an average diameter of 130-192 nm. The diameters of the AgNPs were in the range of 15-22 nm. The nanofibers significantly inhibited growth of Escherichia coli and Staphylococcus aureus bacteria. PVA/COS-AgNP nanofibers accelerated the rate of wound healing over that of the control (gauze). The results of our in vitro and in vivo animal experiments suggest that PVA/COS-AgNP nanofibers should be of greater interest than PVA/COS/AgNO3 nanofibers for clinical use as a bioactive wound dressing.

  3. Preclinical safety evaluation of IQG-607 in rats: Acute and repeated dose toxicity studies.

    PubMed

    Rodrigues-Junior, Valnês S; Machado, Pablo; Calixto, João B; Siqueira, Jarbas M; Andrade, Edinéia; Bento, Allisson; Campos, Maria M; Basso, Luiz A; Santos, Diógenes S

    2017-02-20

    In the present study, we evaluated the safety and the possible toxic effects of IQG-607 after acute and 90-day repeated administrations in rats. Single oral administration of IQG-607 (300 or 2000 mg/kg) on female rats did not result in any mortality. No gross lesions were observed in the animals at necropsy. Ninety-day administration test resulted in 20% of deaths, in both male and female rats administered with the highest dose of IQG-607, 300 mg/kg. Repeated administration of the IQG 607 (25, 100 and 300 mg/kg) did not result in any significant body mass alteration, or changes in food and water consumption. The most important clinical sign observed was salivation in both sexes. Importantly, long-term treatment with IQG-607 did not induce alterations in any hematological (for both sex) and serum biochemical (for female) parameters evaluated, even at the highest dose tested. Treatment of male rats with 100 or 300 mg/kg of IQG-607 decreased total cholesterol levels, while animals treated with 100 mg/kg also presented reduction on triglyceride levels. Of note, no treatment induced significant histopathological alterations in tissues of all organs and glands analyzed, even in that group that received the highest dose of IQG-607.

  4. The Usefulness of Systematic Reviews of Animal Experiments for the Design of Preclinical and Clinical Studies

    PubMed Central

    de Vries, Rob B. M.; Wever, Kimberley E.; Avey, Marc T.; Stephens, Martin L.; Sena, Emily S.; Leenaars, Marlies

    2014-01-01

    The question of how animal studies should be designed, conducted, and analyzed remains underexposed in societal debates on animal experimentation. This is not only a scientific but also a moral question. After all, if animal experiments are not appropriately designed, conducted, and analyzed, the results produced are unlikely to be reliable and the animals have in effect been wasted. In this article, we focus on one particular method to address this moral question, namely systematic reviews of previously performed animal experiments. We discuss how the design, conduct, and analysis of future (animal and human) experiments may be optimized through such systematic reviews. In particular, we illustrate how these reviews can help improve the methodological quality of animal experiments, make the choice of an animal model and the translation of animal data to the clinic more evidence-based, and implement the 3Rs. Moreover, we discuss which measures are being taken and which need to be taken in the future to ensure that systematic reviews will actually contribute to optimizing experimental design and thereby to meeting a necessary condition for making the use of animals in these experiments justified. PMID:25541545

  5. Preclinical positron emission tomography scanner based on a monolithic annulus of scintillator: initial design study.

    PubMed

    Stolin, Alexander V; Martone, Peter F; Jaliparthi, Gangadhar; Raylman, Raymond R

    2017-01-01

    Positron emission tomography (PET) scanners designed for imaging of small animals have transformed translational research by reducing the necessity to invasively monitor physiology and disease progression. Virtually all of these scanners are based on the use of pixelated detector modules arranged in rings. This design, while generally successful, has some limitations. Specifically, use of discrete detector modules to construct PET scanners reduces detection sensitivity and can introduce artifacts in reconstructed images, requiring the use of correction methods. To address these challenges, and facilitate measurement of photon depth-of-interaction in the detector, we investigated a small animal PET scanner (called AnnPET) based on a monolithic annulus of scintillator. The scanner was created by placing 12 flat facets around the outer surface of the scintillator to accommodate placement of silicon photomultiplier arrays. Its performance characteristics were explored using Monte Carlo simulations and sections of the NEMA NU4-2008 protocol. Results from this study revealed that AnnPET's reconstructed spatial resolution is predicted to be [Formula: see text] full width at half maximum in the radial, tangential, and axial directions. Peak detection sensitivity is predicted to be 10.1%. Images of simulated phantoms (mini-hot rod and mouse whole body) yielded promising results, indicating the potential of this system for enhancing PET imaging of small animals.

  6. Confidentiality in preclinical Alzheimer disease studies: when research and medical records meet.

    PubMed

    Arias, Jalayne J; Karlawish, Jason

    2014-02-25

    Clinical trials to advance the diagnosis and treatment of Alzheimer disease (AD) may expose research subjects to discrimination risks. An individual enrolled in a research study that uses positive test results from amyloid PET imaging or CSF measures of β-amyloid 42 as inclusion criteria has biomarkers indicative of AD pathology. If insurers and employers learn this information, it could expose subjects to discrimination. Unfortunately, current legal and regulatory mechanisms are not sufficient to protect against harms that have significant consequences for subjects. Existing law that prohibits employment and insurance discrimination based on genetic status does not apply to amyloid biomarkers or any other biomarkers for neurodegenerative diseases. Gaps in legal protections fail to protect research subjects from discrimination by long-term care and disability insurers. This risk is particularly concerning because individuals with AD dementia ultimately need long-term care services. To maximize subject protections and advance valuable research, policymakers, investigators, and research institutions must address shortcomings in the design of the electronic medical record, revise laws to limit discrimination, and develop practices that inform research participants of risks associated with loss of confidentiality.

  7. Preclinical studies of vascular acting photosensitizer bacteriopheophorbide for the treatment of prostate cancer

    NASA Astrophysics Data System (ADS)

    Hetzel, Fred W.; Chen, Qun; Luck, David; Beckers, Jill; Huang, Zheng

    2004-06-01

    Photodynamic therapy (PDT) mediated with vascular acting photosensitizer pd-bacteriopheophorbide (Tookad), is investigated as an alternative modality for the total ablation of prostate cancer. In vivo normal canine prostate is used as the animal model. Interstitial PDT was performed by irradiating the surgically exposed prostates with a diode laser (763 nm, 150 mW/cm) to activate the IV infused photosensitizer drug. The prostate and its adjacent tissues were harvested and subjected to histopathological examination. At one-week post PDT, the animals recovered well with little or no urethral complications. Prostatic urethra and prostate adjacent tissues (bladder and underlying colon) were well preserved. PDT induced prostate lesions were characterized by marked hemorrhagic necrosis. Prostate lesions could be detected by MRI scan as early as 48 h post PDT. Maximum lesion size of 1.5 cm3 and 2.9 cm3 could be achieved at 50 J/cm and 100 J/cm, respectively, with interstitial treatment using a single 1-cm diffuser fiber, suggesting the Tookad-PDT is very effective in ablating prostatic tissue. Pharmacokinetic studies show that the photosensitizer is cleared rapidly from the circulation. In conclusion, the novel photosensitizer Tookad mediated PDT may provide an effective alternative to treat localized prostate cancer.

  8. The Natural Fungal Metabolite Beauvericin Exerts Anticancer Activity In Vivo: A Pre-Clinical Pilot Study.

    PubMed

    Heilos, Daniela; Rodríguez-Carrasco, Yelko; Englinger, Bernhard; Timelthaler, Gerald; van Schoonhoven, Sushilla; Sulyok, Michael; Boecker, Simon; Süssmuth, Roderich D; Heffeter, Petra; Lemmens-Gruber, Rosa; Dornetshuber-Fleiss, Rita; Berger, Walter

    2017-08-24

    Recently, in vitro anti-cancer properties of beauvericin, a fungal metabolite were shown in various cancer cell lines. In this study, we assessed the specificity of this effect by comparing beauvericin cytotoxicity in malignant versus non-malignant cells. Moreover, we tested in vivo anticancer effects of beauvericin by treating BALB/c and CB-17/SCID mice bearing murine CT-26 or human KB-3-1-grafted tumors, respectively. Tumor size and weight were measured and histological sections were evaluated by Ki-67 and H/E staining as well as TdT-mediated-dUTP-nick-end (TUNEL) labeling. Beauvericin levels were determined in various tissues and body fluids by LC-MS/MS. In addition to a more pronounced activity against malignant cells, we detected decreased tumor volumes and weights in beauvericin-treated mice compared to controls in both the allo- and the xenograft model without any adverse effects. No significant differences were detected concerning percentages of proliferating and mitotic cells in tumor sections from treated and untreated mice. However, a significant increase of necrotic areas within whole tumor sections of beauvericin-treated mice was found in both models corresponding to an enhanced number of TUNEL-positive, i.e., apoptotic, cells. Furthermore, moderate beauvericin accumulation was detected in tumor tissues. In conclusion, we suggest beauvericin as a promising novel natural compound for anticancer therapy.

  9. Effect of selective inhibitors of inflammation on oral mucositis: preclinical studies.

    PubMed

    Haagen, Julia; Krohn, Hanna; Röllig, Sophie; Schmidt, Margret; Wolfram, Kathrin; Dörr, Wolfgang

    2009-09-01

    Oral mucositis is a severe, dose-limiting side effect of radio(chemo)therapy for head and neck tumors. The epithelial radiation response (ulceration) is accompanied by inflammatory changes. Their interaction with the epithelial processes remains unclear. The present study was initiated to determine the effect of inhibition of TNF-alpha or COX-2 on the epithelial radiation response in the mouse tongue model. Daily fractionated irradiation was given with 5 x 3 Gy/week over one (days 0-4) or two weeks (days 0-4, 7-11). Each protocol was terminated by graded test doses (5 dose groups, 10 animals each) to a defined area of the lower tongue surface to generate full dose-effect curves for mucosal ulceration. A TNF-alpha inhibiting antibody (Infliximab) or a COX-2 inhibitor (Celecoxib) was administered. No effect of Infliximab or Celecoxib was found in any of the protocols. Isoeffective doses for ulcer induction were unchanged. Also, the time course of the response was largely unaffected. Inhibition of TNF-alpha or COX-2, two dominating inflammatory pathways, did not result in modulation of the response of oral epithelium during fractionated irradiation. This suggests that the inflammatory changes mediated through TNF-alpha or COX-2 are not relevant for the epithelial radiation response of oral mucosa.

  10. Intraoperative image-guided transoral robotic surgery: pre-clinical studies.

    PubMed

    Liu, Wen P; Reaugamornrat, Sureerat; Sorger, Jonathan M; Siewerdsen, Jeffrey H; Taylor, Russell H; Richmon, Jeremy D

    2015-06-01

    Adequate resection of oropharyngeal neoplasms with transoral robotic surgery (TORS) poses multiple challenges, including difficulty with access, inability to palpate the tumor, loss of landmarks, and intraoperative patient positioning with mouth retractor and tongue extended creating significant tissue distortion from preoperative imaging. This study evaluates a workflow integrating intraoperative cone beam computed tomography (CBCT) for image-guided TORS through robotic experimentation locating 8-10 embedded targets in five porcine tongues and a cadaveric head phantom, conducted under various modes of visualization and integration of preoperative/intraoperative imaging. A statistically significant improvement in mean target localization error was achieved for both the porcine tongue ((9.8 ± 4.0) mm vs. (5.3 ± 1.3) mm, P-value = 0.0151) and cadaver ((11.2 ± 5.0) mm vs. (5.8 ± 2.5) mm P-value = 0.0189) in experiments comparing scenarios simulating current standard-of-care practice and the proposed image guidance system. Intraoperative image guidance with augmentation of critical surgical structures has the potential to improve target localization for TORS. Copyright © 2014 John Wiley & Sons, Ltd.

  11. [Promoting venous return in plaster cast by AV impulse system. A preclinical study].

    PubMed

    Bulitta, C; Kock, H J; Hanke, J; Sievers, K W; Schmit-Neuerburg, K P

    1996-08-01

    A new pneumatic compression pump--the AV-impulse system--causes increased return of venous blood from the lower limbs to the heart and increases total blood flow in the lower limbs by emptying the plantar venous plexus. Up to date there exist no experiences with using this system in plaster cast. We studied the maximum venous blood flow, the venous blood flow per minute and the venous diameters above the popliteal and femoral vein by duplexsonography in 12 lower limbs of 6 healthy persons before and after applying below-the-knee plaster casts. After applying the plaster cast we observed a slight increase in venous diameter (p = 0.02). By using the AV-impulse-system we observed a significant increase in maximum venous blood flow and venous blood flow per minute (p < 0.05). We demonstrated a significant increase of venous blood return in the deep veins of the lower limbs after applying a low