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

Science.gov (United States)

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 pstudents 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 (pstudents completed the oral exam of the First State Examination significantly earlier than students with a non-EU migration background (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

Bioengineered Temporomandibular Joint Disk Implants: Study Protocol for a Two-Phase Exploratory Randomized Preclinical Pilot Trial in 18 Black Merino Sheep (TEMPOJIMS)

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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

Developing Potential Candidates of Preclinical Preeclampsia

Directory of Open Access Journals (Sweden)

Sandra Founds

2015-11-01

Full Text Available The potential for developing molecules of interest in preclinical preeclampsia from candidate genes that were discovered on gene expression microarray analysis has been challenged by limited access to additional first trimester trophoblast and decidual tissues. The question of whether these candidates encode secreted proteins that may be detected in maternal circulation early in pregnancy has been investigated using various proteomic methods. Pilot studies utilizing mass spectrometry based proteomic assays, along with enzyme linked immunosorbent assays (ELISAs, and Western immunoblotting in first trimester samples are reported. The novel targeted mass spectrometry methods led to robust multiple reaction monitoring assays. Despite detection of several candidates in early gestation, challenges persist. Future antibody-based studies may lead to a novel multiplex protein panel for screening or detection to prevent or mitigate preeclampsia.

Standards and Methodological Rigor in Pulmonary Arterial Hypertension Preclinical and Translational Research.

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Provencher, Steeve; Archer, Stephen L; Ramirez, F Daniel; Hibbert, Benjamin; Paulin, Roxane; Boucherat, Olivier; Lacasse, Yves; Bonnet, Sébastien

2018-03-30

Despite advances in our understanding of the pathophysiology and the management of pulmonary arterial hypertension (PAH), significant therapeutic gaps remain for this devastating disease. Yet, few innovative therapies beyond the traditional pathways of endothelial dysfunction have reached clinical trial phases in PAH. Although there are inherent limitations of the currently available models of PAH, the leaky pipeline of innovative therapies relates, in part, to flawed preclinical research methodology, including lack of rigour in trial design, incomplete invasive hemodynamic assessment, and lack of careful translational studies that replicate randomized controlled trials in humans with attention to adverse effects and benefits. Rigorous methodology should include the use of prespecified eligibility criteria, sample sizes that permit valid statistical analysis, randomization, blinded assessment of standardized outcomes, and transparent reporting of results. Better design and implementation of preclinical studies can minimize inherent flaws in the models of PAH, reduce the risk of bias, and enhance external validity and our ability to distinguish truly promising therapies form many false-positive or overstated leads. Ideally, preclinical studies should use advanced imaging, study several preclinical pulmonary hypertension models, or correlate rodent and human findings and consider the fate of the right ventricle, which is the major determinant of prognosis in human PAH. Although these principles are widely endorsed, empirical evidence suggests that such rigor is often lacking in pulmonary hypertension preclinical research. The present article discusses the pitfalls in the design of preclinical pulmonary hypertension trials and discusses opportunities to create preclinical trials with improved predictive value in guiding early-phase drug development in patients with PAH, which will need support not only from researchers, peer reviewers, and editors but also from

Early, Incomplete, or Preclinical Autoimmune Systemic Rheumatic Diseases and Pregnancy Outcome.

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Spinillo, Arsenio; Beneventi, Fausta; Locatelli, Elena; Ramoni, Vèronique; Caporali, Roberto; Alpini, Claudia; Albonico, Giulia; Cavagnoli, Chiara; Montecucco, Carlomaurizio

2016-10-01

To evaluate the impact of preclinical systemic autoimmune rheumatic disorders on pregnancy outcome. In this longitudinal cohort study, patients were enrolled during the first trimester of pregnancy if they reported having had connective tissue disorder symptoms, were found to be positive for circulating autoantibodies, and on clinical evaluation were judged to have a preclinical or incomplete rheumatic disorder. The incidence of fetal growth restriction (FGR), preeclampsia, and adverse pregnancy outcomes in patients with preclinical rheumatic disorders was compared with that in selected controls, after adjustment for confounders by penalized logistic regression. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Of 5,232 women screened, 150 (2.9%) were initially diagnosed as having a suspected rheumatic disorder. After a mean ± SD postpartum follow-up of 16.7 ± 5.5 months, 64 of these women (42.7%) had no clinically apparent rheumatic disease and 86 (57.3%) had persistent symptoms and positive autoantibody results, including 10 (6.7%) who developed a definitive rheumatic disease. The incidences of preeclampsia/FGR and of small for gestational age (SGA) infants were 5.1% (23 of 450) and 9.3% (42 of 450), respectively, among controls, 12.5% (8 of 640) (OR 2.7 [95% CI 1.1-6.4]) and 18.8% (12 of 64) (OR 2.2 [95% CI 1.1-4.5]), respectively, among women with no clinically apparent disease, and 16.3% (14 of 86) (OR 3.8 [95% CI 1.9-7.7]) and 18.6% (16 of 86) (OR 2.3 [95% CI 1.2-4.3]), respectively, among those with persisting symptoms at follow-up. Mean ± SD umbilical artery Doppler pulsatility indices were higher among women with no clinically apparent disease (0.95 ± 0.2) and those with persisting symptoms (0.96 ± 0.21) than in controls (0.89 ± 0.12) (P = 0.01 and P rheumatic disorders were associated with an increased risk of FGR/preeclampsia and SGA. The impact of these findings and their utility in screening

[Impact of microdose clinical trials in the preclinical stage].

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Kim, Soonih

2014-01-01

A microdose clinical trial may be useful as a safe early-phase exploratory study using doses as low as 100 μg or less for determination of the disposition of a candidate compound in humans in a short period of time. This may increase confidence in candidate compounds, especially those for which it is difficult to predict disposition based on the results of in vitro or preclinical studies. In this study, we examined microdose trials performed in the preclinical stage for two first-in-class compounds with a new mechanism of action. These compounds showed species difference in first pass metabolism in the digestive tract and liver, causing uncertainty in prediction of disposition in humans. For this reason, first-in-human microdose clinical trials were performed. The results showed that the two compounds had effective blood concentrations after oral administration at a dose of 100 mg qd. Administration of an extremely small dose of one (14)C-labeled compound permitted identification of major metabolites. No toxic metabolites were detected. The preclinical toxic dose was determined based on prediction of blood exposure at the estimated maximum clinical dose. For the other candidate compound, the findings of the microdose trial indicated a high bioavailability after oral administration and low hepatic clearance after intravenous administration. These results suggested only a small risk of a change in disposition in patients with hepatic disorder. The data obtained for the two compounds suggest that microdose clinical trials can be useful for improving the process of candidate selection in the preclinical stage.

Preclinical stress research: where are we headed? An early career investigator's perspective.

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Gururajan, Anand; Kos, Aron; Lopez, Juan Pablo

2018-03-07

Stress is a major risk factor in the development of various psychiatric disorders such as depression, anxiety and post-traumatic stress disorder. The use of stress paradigms in preclinical contexts is essential to advance our understanding of the pathophysiology of these disorders. However, they are not without their limitations and in this commentary, we have examined some of the practical issues associated with their use. We also highlight some of the latest techniques to identify their neuromolecular correlates as well as the potentially important and integrative role of computational neuroscience. Finally, we share our perspective on future directions in the field of preclinical stress research.

Development of computational small animal models and their applications in preclinical imaging and therapy research

NARCIS (Netherlands)

Xie, Tianwu; Zaidi, Habib

The development of multimodality preclinical imaging techniques and the rapid growth of realistic computer simulation tools have promoted the construction and application of computational laboratory animal models in preclinical research. Since the early 1990s, over 120 realistic computational animal

Preclinical Polymodal Hallucinations for 13 Years before Dementia with Lewy Bodies

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Abbate, Carlo; Trimarchi, Pietro Davide; Inglese, Silvia; Viti, Niccolò; Cantatore, Alessandra; De Agostini, Lisa; Pirri, Federico; Marino, Lorenza; Bagarolo, Renzo

2014-01-01

Objective. We describe a case of dementia with Lewy bodies (DLB) that presented long-lasting preclinical complex polymodal hallucinations. Background. Few studies have deeply investigated the characteristics of hallucinations in DLB, especially in the preclinical phase. Moreover, the clinical phenotype of mild cognitive impairment-(MCI-) DLB is poorly understood. Methods. The patient was followed for 4 years and a selective phenomenological and cognitive study was performed at the predementia stage. Results. The phenomenological study showed the presence of hypnagogic and hypnopompic hallucinations that allowed us to make a differential diagnosis between DLB and Charles Bonnet syndrome (CBS). The neuropsychological evaluation showed a multiple domain without amnesia MCI subtype with prefrontal dysexecutive, visuoperceptual, and visuospatial impairments and simultanagnosia, which has not previously been reported in MCI-DLB. Conclusions. This study extends the prognostic value of hallucinations for DLB to the preclinical phases. It supports and refines the MCI-DLB concept and identifies simultanagnosia as a possible early cognitive marker. Finally, it confirms an association between hallucinations and visuoperceptual impairments at an intermediate stage of the disease course and strongly supports the hypothesis that hallucinations in the earliest stages of DLB may reflect a narcolepsy-like REM-sleep disorder. PMID:24868122

Neuropsychiatric symptoms predict hypometabolism in preclinical Alzheimer disease.

Science.gov (United States)

Ng, Kok Pin; Pascoal, Tharick A; Mathotaarachchi, Sulantha; Chung, Chang-Oh; Benedet, Andréa L; Shin, Monica; Kang, Min Su; Li, Xiaofeng; Ba, Maowen; Kandiah, Nagaendran; Rosa-Neto, Pedro; Gauthier, Serge

2017-05-09

To identify regional brain metabolic dysfunctions associated with neuropsychiatric symptoms (NPS) in preclinical Alzheimer disease (AD). We stratified 115 cognitively normal individuals into preclinical AD (both amyloid and tau pathologies present), asymptomatic at risk for AD (either amyloid or tau pathology present), or healthy controls (no amyloid or tau pathology present) using [ 18 F]florbetapir PET and CSF phosphorylated tau biomarkers. Regression and voxel-based regression models evaluated the relationships between baseline NPS measured by the Neuropsychiatric Inventory (NPI) and baseline and 2-year change in metabolism measured by [ 18 F]fluorodeoxyglucose (FDG) PET. Individuals with preclinical AD with higher NPI scores had higher [ 18 F]FDG uptake in the posterior cingulate cortex (PCC), ventromedial prefrontal cortex, and right anterior insula at baseline. High NPI scores predicted subsequent hypometabolism in the PCC over 2 years only in individuals with preclinical AD. Sleep/nighttime behavior disorders and irritability and lability were the components of the NPI that drove this metabolic dysfunction. The magnitude of NPS in preclinical cases, driven by sleep behavior and irritability domains, is linked to transitory metabolic dysfunctions within limbic networks vulnerable to the AD process and predicts subsequent PCC hypometabolism. These findings support an emerging conceptual framework in which NPS constitute an early clinical manifestation of AD pathophysiology. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

Preliminary study for small animal preclinical hadrontherapy facility

Energy Technology Data Exchange (ETDEWEB)

Russo, G. [Institute of Molecular Bioimaging and Physiology, IBFM CNR-LATO, Cefalú (Italy); Pisciotta, P., E-mail: pietro.pisciotta@ibfm.cnr.it [Institute of Molecular Bioimaging and Physiology, IBFM CNR-LATO, Cefalú (Italy); National Institute for Nuclear Physics, Laboratori Nazionali del Sud, INFN-LNS, Catania (Italy); Cirrone, G.A.P.; Romano, F. [National Institute for Nuclear Physics, Laboratori Nazionali del Sud, INFN-LNS, Catania (Italy); Cammarata, F.; Marchese, V.; Forte, G.I.; Lamia, D.; Minafra, L.; Bravatá, V. [Institute of Molecular Bioimaging and Physiology, IBFM CNR-LATO, Cefalú (Italy); Acquaviva, R. [University of Catania, Catania (Italy); Gilardi, M.C. [Institute of Molecular Bioimaging and Physiology, IBFM CNR-LATO, Cefalú (Italy); Cuttone, G. [National Institute for Nuclear Physics, Laboratori Nazionali del Sud, INFN-LNS, Catania (Italy)

2017-02-21

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

Preliminary study for small animal preclinical hadrontherapy facility

Science.gov (United States)

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

Preliminary study for small animal preclinical hadrontherapy facility

International Nuclear Information System (INIS)

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.

2017-01-01

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

The development of neural stimulators: a review of preclinical safety and efficacy studies.

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Shepherd, Robert K; Villalobos, Joel; Burns, Owen; Nayagam, David

2018-05-14

Given the rapid expansion of the field of neural stimulation and the rigorous regulatory approval requirements required before these devices can be applied clinically, it is important that there is clarity around conducting preclinical safety and efficacy studies required for the development of this technology. The present review examines basic design principles associated with the development of a safe neural stimulator and describes the suite of preclinical safety studies that need to be considered when taking a device to clinical trial. Neural stimulators are active implantable devices that provide therapeutic intervention, sensory feedback or improved motor control via electrical stimulation of neural or neuro-muscular tissue in response to trauma or disease. Because of their complexity, regulatory bodies classify these devices in the highest risk category (Class III), and they are therefore required to go through a rigorous regulatory approval process before progressing to market. The successful development of these devices is achieved through close collaboration across disciplines including engineers, scientists and a surgical/clinical team, and the adherence to clear design principles. Preclinical studies form one of several key components in the development pathway from concept to product release of neural stimulators. Importantly, these studies provide iterative feedback in order to optimise the final design of the device. Key components of any preclinical evaluation include: in vitro studies that are focussed on device reliability and include accelerated testing under highly controlled environments; in vivo studies using animal models of the disease or injury in order to assess safety and, given an appropriate animal model, the efficacy of the technology under both passive and electrically active conditions; and human cadaver and ex vivo studies designed to ensure the device's form factor conforms to human anatomy, to optimise the surgical approach and to

Preclinical experimental stress studies: protocols, assessment and comparison.

Science.gov (United States)

Bali, Anjana; Jaggi, Amteshwar Singh

2015-01-05

Stress is a state of threatened homeostasis during which a variety of adaptive processes are activated to produce physiological and behavioral changes. Preclinical models are pivotal for understanding these physiological or pathophysiological changes in the body in response to stress. Furthermore, these models are also important for the development of novel pharmacological agents for stress management. The well described preclinical stress models include immobilization, restraint, electric foot shock and social isolation stress. Stress assessment in animals is done at the behavioral level using open field, social interaction, hole board test; at the biochemical level by measuring plasma corticosterone and ACTH; at the physiological level by measuring food intake, body weight, adrenal gland weight and gastric ulceration. Furthermore the comparison between different stressors including electric foot shock, immobilization and cold stressor is described in terms of intensity, hormonal release, protein changes in brain, adaptation and sleep pattern. This present review describes these preclinical stress protocols, and stress assessment at different levels. Copyright © 2014 Elsevier B.V. All rights reserved.

Preclinical Polymodal Hallucinations for 13 Years before Dementia with Lewy Bodies

Directory of Open Access Journals (Sweden)

Carlo Abbate

2014-01-01

Full Text Available Objective. We describe a case of dementia with Lewy bodies (DLB that presented long-lasting preclinical complex polymodal hallucinations. Background. Few studies have deeply investigated the characteristics of hallucinations in DLB, especially in the preclinical phase. Moreover, the clinical phenotype of mild cognitive impairment-(MCI- DLB is poorly understood. Methods. The patient was followed for 4 years and a selective phenomenological and cognitive study was performed at the predementia stage. Results. The phenomenological study showed the presence of hypnagogic and hypnopompic hallucinations that allowed us to make a differential diagnosis between DLB and Charles Bonnet syndrome (CBS. The neuropsychological evaluation showed a multiple domain without amnesia MCI subtype with prefrontal dysexecutive, visuoperceptual, and visuospatial impairments and simultanagnosia, which has not previously been reported in MCI-DLB. Conclusions. This study extends the prognostic value of hallucinations for DLB to the preclinical phases. It supports and refines the MCI-DLB concept and identifies simultanagnosia as a possible early cognitive marker. Finally, it confirms an association between hallucinations and visuoperceptual impairments at an intermediate stage of the disease course and strongly supports the hypothesis that hallucinations in the earliest stages of DLB may reflect a narcolepsy-like REM-sleep disorder.

Contribution of micro-scanner in the preclinical study of hepatic and pancreatic cancer treatments in rat

International Nuclear Information System (INIS)

Youssef Azer Akladios, Cherif

2010-01-01

Animal experimentation is an unavoidable step in preclinical studies and relies on small animals. In vivo imaging constitutes a precious tool giving information on anatomy, biochemistry, physiology, genetic, pharmacology, while saving cell and tissue integrities of investigated animals. It opens wide the scientific perspective in the field of biological development, physiopathology of diseases, as well as in oncology, from early diagnosis to cancer treatment. This thesis had demonstrated the relevance of micro-scanner in the longitudinal follow up and the management of ortho-topic models of hepatic and pancreatic carcinoma in the rat. For both of these cancers, known to be very poorly or even non curable, there is an urgent need of research on the bases of their onco-genesis as of investigation of the resulting new therapeutic routes. The results of our thesis suggest a role for micro-CT in the preclinical evaluation of their emerging therapies. As far as animal experiment is concerned, in vivo micro-scanner imaging permits, beside a reduction in the number of experimental animals, to establish new (imaging) end-points allowing experiment ending before any sign of animal suffering. It fulfils the main requirements of animal experiment. (author) [fr

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

Science.gov (United States)

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.

Translational reciprocity: bridging the gap between preclinical studies and clinical treatment of stress effects on the adolescent brain.

Science.gov (United States)

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.

Developmental origins of metabolic disorders: The need for biomarker candidates and therapeutic targets from adequate preclinical models

Directory of Open Access Journals (Sweden)

Antonio Gonzalez-Bulnes

2016-03-01

Full Text Available The investigation on obesity and associated disorders have changed from an scenario in which genome drove the phenotype to a dynamic setup in which prenatal and early-postnatal conditions are determinant. However, research in human beings is difficult due to confounding factors (lifestyle and socioeconomic heterogeneity plus ethical issues. Hence, there is currently an intensive effort for developing adequate preclinical models, aiming for an adequate combination of basic studies in rodent models and specific preclinical studies in large animals. The results of these research strategies may increase the identification and development of contrasted biomarkers and therapeutic targets.

Challenges for Preclinical Investigations of Human Biofield Modalities

Science.gov (United States)

Gronowicz, Gloria; Bengston, William

2015-01-01

Preclinical models for studying the effects of the human biofield have great potential to advance our understanding of human biofield modalities, which include external qigong, Johrei, Reiki, therapeutic touch, healing touch, polarity therapy, pranic healing, and other practices. A short history of Western biofield studies using preclinical models is presented and demonstrates numerous and consistent examples of human biofields significantly affecting biological systems both in vitro and in vivo. Methodological issues arising from these studies and practical solutions in experimental design are presented. Important questions still left unanswered with preclinical models include variable reproducibility, dosing, intentionality of the practitioner, best preclinical systems, and mechanisms. Input from the biofield practitioners in the experimental design is critical to improving experimental outcomes; however, the development of standard criteria for uniformity of practice and for inclusion of multiple practitioners is needed. Research in human biofield studies involving preclinical models promises a better understanding of the mechanisms underlying the efficacy of biofield therapies and will be important in guiding clinical protocols and integrating treatments with conventional medical therapies. PMID:26665042

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

Science.gov (United States)

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.

Surgeon Involvement in Pre-Clinical Medical Education: Attitudes of Directors of Education

Directory of Open Access Journals (Sweden)

Simon Turner

2012-04-01

Full Text Available Background: Application rates to surgical residencies have shown a downward trend recently. Introducing students to surgeons early in medical school can increase interest in surgery as a career and enhance the instruction of important surgical topics. Directors of undergraduate medical education have unique insight and influence regarding the participation of surgeons in pre-clinical education. Methods: To understand the attitudes of these educators towards surgeons as teachers in pre-clinical programs, a survey was administered to the directors of undergraduate medical education at each of the English-language medical schools in Canada. Results: Educators estimate the participation of surgeons in all categories of pre-clinical education to be low, despite being valuable, and think that it should be increased. The most significant barrier to participation identified was a lack of surgeons’ time. Conclusions: Despite the value of surgeons participating in pre-clinical education, their rate of participation is low. Steps should be taken to facilitate the involvement of surgeons in this phase of education, which may lead to improved education for students and increased student interest in surgery residencies.

Factors influencing the approaches to studying of preclinical and clinical students and postgraduate trainees

Directory of Open Access Journals (Sweden)

Samarasekera Dharmabandu N

2011-05-01

Full Text Available Abstract Background Students can be classified into three categories depending on their approaches to studying; namely, deep approach (DA, strategic approach (SA and surface apathetic or superficial approach (SAA. The aim of this study was to identify factors affecting the approaches to studying among Sri Lankan medical undergraduates and post graduate trainees and to analyze the change in the pattern of study skills with time and experience. Method Pre-clinical and clinical students of the Faculty of Medicine, University of Colombo and postgraduate trainees in Surgery at the National Hospital of Sri Lanka were invited to complete the Approaches and Study Skills Inventory for Students (ASSIST questionnaire. Results A total of 187 pre clinical (M: F = 96:91, 124 clinical (M: F = 61:63 and 53 post graduate trainees (M: F = 50:3 participated in the study. Approaches of male and female students were similar. SA was significantly affected by age among the preclinical students (p = 0.01, but not in other groups. Among pre-clinical students, males preferred a teacher who supported understanding (p = 0.04 but females preferred a passive transmission of information (p Conclusion Different factors affect the approach to studying in different groups but these explain only a small fraction of the variance observed.

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

International Nuclear Information System (INIS)

Medin, Paul M.; Boike, Thomas P.

2011-01-01

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.

Evaluation of Cholinergic Deficiency in Preclinical Alzheimer’s Disease Using Pupillometry

Directory of Open Access Journals (Sweden)

Shaun Frost

2017-01-01

Full Text Available Cortical cholinergic deficiency is prominent in Alzheimer’s disease (AD, and published findings of diminished pupil flash response in AD suggest that this deficiency may extend to the visual cortical areas and anterior eye. Pupillometry is a low-cost, noninvasive technique that may be useful for monitoring cholinergic deficits which generally lead to memory and cognitive disorders. The aim of the study was to evaluate pupillometry for early detection of AD by comparing the pupil flash response (PFR in AD (N=14 and cognitively normal healthy control (HC, N=115 participants, with the HC group stratified according to high (N=38 and low (N=77 neocortical amyloid burden (NAB. Constriction phase PFR parameters were significantly reduced in AD compared to HC (maximum acceleration p<0.05, maximum velocity p<0.0005, average velocity p<0.005, and constriction amplitude p<0.00005. The high-NAB HC subgroup had reduced PFR response cross-sectionally, and also a greater decline longitudinally, compared to the low-NAB subgroup, suggesting changes to pupil response in preclinical AD. The results suggest that PFR changes may occur in the preclinical phase of AD. Hence, pupillometry has a potential as an adjunct for noninvasive, cost-effective screening for preclinical AD.

Stem Cells for Cartilage Repair: Preclinical Studies and Insights in Translational Animal Models and Outcome Measures

Directory of Open Access Journals (Sweden)

Melissa Lo Monaco

2018-01-01

Full Text Available Due to the restricted intrinsic capacity of resident chondrocytes to regenerate the lost cartilage postinjury, stem cell-based therapies have been proposed as a novel therapeutic approach for cartilage repair. Moreover, stem cell-based therapies using mesenchymal stem cells (MSCs or induced pluripotent stem cells (iPSCs have been used successfully in preclinical and clinical settings. Despite these promising reports, the exact mechanisms underlying stem cell-mediated cartilage repair remain uncertain. Stem cells can contribute to cartilage repair via chondrogenic differentiation, via immunomodulation, or by the production of paracrine factors and extracellular vesicles. But before novel cell-based therapies for cartilage repair can be introduced into the clinic, rigorous testing in preclinical animal models is required. Preclinical models used in regenerative cartilage studies include murine, lapine, caprine, ovine, porcine, canine, and equine models, each associated with its specific advantages and limitations. This review presents a summary of recent in vitro data and from in vivo preclinical studies justifying the use of MSCs and iPSCs in cartilage tissue engineering. Moreover, the advantages and disadvantages of utilizing small and large animals will be discussed, while also describing suitable outcome measures for evaluating cartilage repair.

Stem Cells for Cartilage Repair: Preclinical Studies and Insights in Translational Animal Models and Outcome Measures.

Science.gov (United States)

Lo Monaco, Melissa; Merckx, Greet; Ratajczak, Jessica; Gervois, Pascal; Hilkens, Petra; Clegg, Peter; Bronckaers, Annelies; Vandeweerd, Jean-Michel; Lambrichts, Ivo

2018-01-01

Due to the restricted intrinsic capacity of resident chondrocytes to regenerate the lost cartilage postinjury, stem cell-based therapies have been proposed as a novel therapeutic approach for cartilage repair. Moreover, stem cell-based therapies using mesenchymal stem cells (MSCs) or induced pluripotent stem cells (iPSCs) have been used successfully in preclinical and clinical settings. Despite these promising reports, the exact mechanisms underlying stem cell-mediated cartilage repair remain uncertain. Stem cells can contribute to cartilage repair via chondrogenic differentiation, via immunomodulation, or by the production of paracrine factors and extracellular vesicles. But before novel cell-based therapies for cartilage repair can be introduced into the clinic, rigorous testing in preclinical animal models is required. Preclinical models used in regenerative cartilage studies include murine, lapine, caprine, ovine, porcine, canine, and equine models, each associated with its specific advantages and limitations. This review presents a summary of recent in vitro data and from in vivo preclinical studies justifying the use of MSCs and iPSCs in cartilage tissue engineering. Moreover, the advantages and disadvantages of utilizing small and large animals will be discussed, while also describing suitable outcome measures for evaluating cartilage repair.

Development of computational small animal models and their applications in preclinical imaging and therapy research.

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Xie, Tianwu; Zaidi, Habib

2016-01-01

The development of multimodality preclinical imaging techniques and the rapid growth of realistic computer simulation tools have promoted the construction and application of computational laboratory animal models in preclinical research. Since the early 1990s, over 120 realistic computational animal models have been reported in the literature and used as surrogates to characterize the anatomy of actual animals for the simulation of preclinical studies involving the use of bioluminescence tomography, fluorescence molecular tomography, positron emission tomography, single-photon emission computed tomography, microcomputed tomography, magnetic resonance imaging, and optical imaging. Other applications include electromagnetic field simulation, ionizing and nonionizing radiation dosimetry, and the development and evaluation of new methodologies for multimodality image coregistration, segmentation, and reconstruction of small animal images. This paper provides a comprehensive review of the history and fundamental technologies used for the development of computational small animal models with a particular focus on their application in preclinical imaging as well as nonionizing and ionizing radiation dosimetry calculations. An overview of the overall process involved in the design of these models, including the fundamental elements used for the construction of different types of computational models, the identification of original anatomical data, the simulation tools used for solving various computational problems, and the applications of computational animal models in preclinical research. The authors also analyze the characteristics of categories of computational models (stylized, voxel-based, and boundary representation) and discuss the technical challenges faced at the present time as well as research needs in the future.

Development of computational small animal models and their applications in preclinical imaging and therapy research

Energy Technology Data Exchange (ETDEWEB)

Xie, Tianwu [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211 (Switzerland); Zaidi, Habib, E-mail: habib.zaidi@hcuge.ch [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211 (Switzerland); Geneva Neuroscience Center, Geneva University, Geneva CH-1205 (Switzerland); Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen 9700 RB (Netherlands)

2016-01-15

The development of multimodality preclinical imaging techniques and the rapid growth of realistic computer simulation tools have promoted the construction and application of computational laboratory animal models in preclinical research. Since the early 1990s, over 120 realistic computational animal models have been reported in the literature and used as surrogates to characterize the anatomy of actual animals for the simulation of preclinical studies involving the use of bioluminescence tomography, fluorescence molecular tomography, positron emission tomography, single-photon emission computed tomography, microcomputed tomography, magnetic resonance imaging, and optical imaging. Other applications include electromagnetic field simulation, ionizing and nonionizing radiation dosimetry, and the development and evaluation of new methodologies for multimodality image coregistration, segmentation, and reconstruction of small animal images. This paper provides a comprehensive review of the history and fundamental technologies used for the development of computational small animal models with a particular focus on their application in preclinical imaging as well as nonionizing and ionizing radiation dosimetry calculations. An overview of the overall process involved in the design of these models, including the fundamental elements used for the construction of different types of computational models, the identification of original anatomical data, the simulation tools used for solving various computational problems, and the applications of computational animal models in preclinical research. The authors also analyze the characteristics of categories of computational models (stylized, voxel-based, and boundary representation) and discuss the technical challenges faced at the present time as well as research needs in the future.

Development of computational small animal models and their applications in preclinical imaging and therapy research

International Nuclear Information System (INIS)

Xie, Tianwu; Zaidi, Habib

2016-01-01

The development of multimodality preclinical imaging techniques and the rapid growth of realistic computer simulation tools have promoted the construction and application of computational laboratory animal models in preclinical research. Since the early 1990s, over 120 realistic computational animal models have been reported in the literature and used as surrogates to characterize the anatomy of actual animals for the simulation of preclinical studies involving the use of bioluminescence tomography, fluorescence molecular tomography, positron emission tomography, single-photon emission computed tomography, microcomputed tomography, magnetic resonance imaging, and optical imaging. Other applications include electromagnetic field simulation, ionizing and nonionizing radiation dosimetry, and the development and evaluation of new methodologies for multimodality image coregistration, segmentation, and reconstruction of small animal images. This paper provides a comprehensive review of the history and fundamental technologies used for the development of computational small animal models with a particular focus on their application in preclinical imaging as well as nonionizing and ionizing radiation dosimetry calculations. An overview of the overall process involved in the design of these models, including the fundamental elements used for the construction of different types of computational models, the identification of original anatomical data, the simulation tools used for solving various computational problems, and the applications of computational animal models in preclinical research. The authors also analyze the characteristics of categories of computational models (stylized, voxel-based, and boundary representation) and discuss the technical challenges faced at the present time as well as research needs in the future

Pre-clinical functional magnetic resonance imaging. Pt. I. The kidney

Energy Technology Data Exchange (ETDEWEB)

Zoellner, Frank G.; Kalayciyan, Raffi; Chacon-Caldera, Jorge; Zimmer, Fabian; Schad, Lothar R. [Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine

2014-07-01

The prevalence of chronic kidney disease (CKD) is increasing worldwide. In Europe alone, at least 8% of the population currently has some degree of CKD. CKD is associated with serious comorbidity, reduced life expectancy, and high economic costs; hence, the early detection and adequate treatment of kidney disease is important. Pre-clinical research can not only give insights into the mechanisms of the various kidney diseases but it also allows for investigating the outcome of new drugs developed to treat kidney disease. Functional magnetic resonance imaging provides non-invasive access to tissue and organ function in animal models. Advantages over classical animal research approaches are numerous: the same animal might be repeatedly imaged to investigate a progress or a treatment of disease over time. This has also a direct impact on animal welfare and the refinement of classical animal experiments as the number of animals in the studies might be reduced. In this paper, we review current state of the art in functional magnetic resonance imaging with a focus on pre-clinical kidney imaging.

Pre-clinical functional magnetic resonance imaging. Pt. I. The kidney

International Nuclear Information System (INIS)

Zoellner, Frank G.; Kalayciyan, Raffi; Chacon-Caldera, Jorge; Zimmer, Fabian; Schad, Lothar R.

2014-01-01

The prevalence of chronic kidney disease (CKD) is increasing worldwide. In Europe alone, at least 8% of the population currently has some degree of CKD. CKD is associated with serious comorbidity, reduced life expectancy, and high economic costs; hence, the early detection and adequate treatment of kidney disease is important. Pre-clinical research can not only give insights into the mechanisms of the various kidney diseases but it also allows for investigating the outcome of new drugs developed to treat kidney disease. Functional magnetic resonance imaging provides non-invasive access to tissue and organ function in animal models. Advantages over classical animal research approaches are numerous: the same animal might be repeatedly imaged to investigate a progress or a treatment of disease over time. This has also a direct impact on animal welfare and the refinement of classical animal experiments as the number of animals in the studies might be reduced. In this paper, we review current state of the art in functional magnetic resonance imaging with a focus on pre-clinical kidney imaging.

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

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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.

Diagnostic and prognostic role of semantic processing in preclinical Alzheimer's disease.

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Venneri, Annalena; Jahn-Carta, Caroline; Marco, Matteo De; Quaranta, Davide; Marra, Camillo

2018-06-13

Relatively spared during most of the timeline of normal aging, semantic memory shows a subtle yet measurable decline even during the pre-clinical stage of Alzheimer's disease. This decline is thought to reflect early neurofibrillary changes and impairment is detectable using tests of language relying on lexical-semantic abilities. A promising approach is the characterization of semantic parameters such as typicality and age of acquisition of words, and propositional density from verbal output. Seminal research like the Nun Study or the analysis of the linguistic decline of famous writers and politicians later diagnosed with Alzheimer's disease supports the early diagnostic value of semantic processing and semantic memory. Moreover, measures of these skills may play an important role for the prognosis of patients with mild cognitive impairment.

Anti-Correlated Cerebrospinal Fluid Biomarker Trajectories in Preclinical Alzheimer's Disease.

Science.gov (United States)

Gomar, Jesus J; Conejero-Goldberg, Concepcion; Davies, Peter; Goldberg, Terry E

2016-01-01

The earliest stage of preclinical Alzheimer's disease (AD) is defined by low levels of cerebrospinal fluid (CSF) amyloid-β (Aβ42). However, covariance in longitudinal dynamic change of Aβ42 and tau in incipient preclinical AD is poorly understood. To examine dynamic interrelationships between Aβ42 and tau in preclinical AD. We followed 47 cognitively intact participants (CI) with available CSF data over four years in ADNI. Based on longitudinal Aβ42 levels in CSF, CI were classified into three groups: 1) Aβ42 stable with normal levels of Aβ42 over time (n = 15); 2) Aβ42 declining with normal Aβ42 levels at baseline but showing decline over time (n = 14); and 3) Aβ42 levels consistently abnormal (n = 18). In the Aβ42 declining group, suggestive of incipient preclinical AD, CSF phosphorylated tau (p-tau) showed a similar longitudinal pattern of increasing abnormality over time (p = 0.0001). Correlation between longitudinal slopes of Aβ42 and p-tau confirmed that both trajectories were anti-correlated (rho = -0.60; p = 0.02). Regression analysis showed that Aβ42 slope (decreasing Aβ42) predicted p-tau slope (increasing p-tau) (R2 = 0.47, p = 0.03). Atrophy in the hippocampus was predicted by the interaction of Aβ42 and p-tau slopes (p anti-correlated trajectory, i.e., as Aβ42 declined, p-tau increased, and thus was suggestive of strong temporal coincidence. Rapid pathogenic cross-talk between Aβ42 and p-tau thus may be evident in very early stages of preclinical AD.

Is performance in pre-clinical assessment a good predictor of the final Doctor of Medicine grade?

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Al-Wardy, Nadia M; Rizvi, Syed G; Bayoumi, Riad A

2009-12-01

To investigate if any correlation exists between students' grades on their final doctor of Medicine (MD) assessment and their overall preclinical grade point average (GPA) and its component parts. Student data available from the Deanship of Admissions and Registration were analyzed. Pearson correlation coefficient was obtained to assess the degree of linear relationship between performance in the preclinical and the MD assessment of 529 students who graduated from the College of Medicine and Health Sciences, Sultan Qaboos University, Al-Khoud, Oman from June 1998 to June 2005. Simple and multiple regression analyses were performed to evaluate individual and combined impact of the preclinical courses' grades on MD grades. Preclinical GPA correlated highly with MD GPA (r=0.641). The science component taught early in the preclinical phase correlated more strongly (r=0.457) than student electives (r=0.246). This correlation was better in the good English group. Students' performance, however, was best in electives, but worst in English. Most students who had low MD GPA (2.5, and limiting the credit hour requirement of electives by the College seems to be justified.

Preclinical studies of dendrimer prodrugs.

Science.gov (United States)

Kojima, Chie

2015-01-01

Dendrimers are synthetic macromolecules with well-defined structures bearing a wide variety of functional groups on their periphery. These groups can be used to conjugate bioactive molecules such as drugs, ligands and imaging agents. Dendrimer prodrugs can be used to improve the water solubility and pharmacokinetic properties of the corresponding free drugs. This article summarizes preclinical studies pertaining to the use of drug-dendrimer conjugates as dendrimer prodrugs for the treatments of various diseases, including cancer and inflammatory diseases. A wide range of anticancer drugs have been conjugated to dendrimers via biodegradable linkers. The side effects of the parent drugs can be markedly reduced using dendrimer prodrugs, with some drugs showing improved efficacy. Anti-inflammatory agents have also been conjugated to dendrimers and used to treat a number of inflammatory diseases. Drug-dendrimer conjugates are preferable to drug-dendrimer complexes, where the use of degradable linkers is critical to the release of the drug. Polyethylene glycol and/or ligands can be added to a dendrimer prodrug, which is useful for the targeting of affected tissues. Imaging probes can also be incorporated into dendrimer prodrugs for the simultaneous delivery of therapeutic and diagnostic agents as 'theranostics.'

Feasibility of spatial frequency domain imaging (SFDI) for optically characterizing a preclinical oncology model.

Science.gov (United States)

Tabassum, Syeda; Zhao, Yanyu; Istfan, Raeef; Wu, Junjie; Waxman, David J; Roblyer, Darren

2016-10-01

Determination of chemotherapy efficacy early during treatment would provide more opportunities for physicians to alter and adapt treatment plans. Diffuse optical technologies may be ideally suited to track early biological events following chemotherapy administration due to low cost and high information content. We evaluated the use of spatial frequency domain imaging (SFDI) to characterize a small animal tumor model in order to move towards the goal of endogenous optical monitoring of cancer therapy in a controlled preclinical setting. The effects of key measurement parameters including the choice of imaging spatial frequency and the repeatability of measurements were evaluated. The precision of SFDI optical property extractions over repeat mouse measurements was determined to be within 3.52% for move and replace experiments. Baseline optical properties and chromophore values as well as intratumor heterogeneity were evaluated over 25 tumors. Additionally, tumor growth and chemotherapy response were monitored over a 45 day longitudinal study in a small number of mice to demonstrate the ability of SFDI to track treatment effects. Optical scattering and oxygen saturation increased as much as 70% and 25% respectively in treated tumors, suggesting SFDI may be useful for preclinical tracking of cancer therapies.

Adiposity Indexes as Phenotype-Specific Markers of Preclinical Metabolic Alterations and Cardiovascular Risk in Polycystic Ovary Syndrome: A Cross-Sectional Study.

Science.gov (United States)

Mario, Fernanda Missio; Graff, Scheila Karen; Spritzer, Poli Mara

2017-05-01

Polycystic ovary syndrome (PCOS) is a common condition in women of reproductive age. 2 PCOS phenotypes (classic and ovulatory) are currently recognized as the most prevalent, with important differences in terms of cardiometabolic features. We studied the performance of different adiposity indexes to predict preclinical metabolic alterations and cardiovascular risk in 234 women with PCOS (173 with classic and 61 with ovulatory PCOS) and 129 controls. Performance of waist circumference, waist-to-height ratio, conicity index, lipid accumulation product, and visceral adiposity index was assessed based on HOMA-IR ≥ 3.8 as reference standard for screening preclinical metabolic alterations and cardiovascular risk factors in each group. Lipid accumulation product had the best accuracy for classic PCOS, and visceral adiposity index had the best accuracy for ovulatory PCOS. By applying the cutoff point of lipid accumulation productcardiometabolic alterations (Prisk for hypertension, dyslipidemia, and impaired glucose tolerance. In ovulatory PCOS, visceral adiposity index ≥ 1.32 was capable of detecting women with significantly higher blood pressure and less favorable glycemic and lipid variables as compared to ovulatory PCOS with lower visceral adiposity index (Pcardiometabolic risk and secure early interventions. © Georg Thieme Verlag KG Stuttgart · New York.

Thinking through postoperative cognitive dysfunction: How to bridge the gap between clinical and pre-clinical perspectives.

Science.gov (United States)

Hovens, Iris B; Schoemaker, Regien G; van der Zee, Eddy A; Heineman, Erik; Izaks, Gerbrand J; van Leeuwen, Barbara L

2012-10-01

Following surgery, patients may experience cognitive decline, which can seriously reduce quality of life. This postoperative cognitive dysfunction (POCD) is mainly seen in the elderly and is thought to be mediated by surgery-induced inflammatory reactions. Clinical studies tend to define POCD as a persisting, generalised decline in cognition, without specifying which cognitive functions are impaired. Pre-clinical research mainly describes early hippocampal dysfunction as a consequence of surgery-induced neuroinflammation. These different approaches to study POCD impede translation between clinical and pre-clinical research outcomes and may hamper the development of appropriate interventions. This article analyses which cognitive domains deteriorate after surgery and which brain areas might be involved. The most important outcomes are: (1) POCD encompasses a wide range of cognitive impairments; (2) POCD affects larger areas of the brain; and (3) individual variation in the vulnerability of neuronal networks to neuroinflammatory mechanisms may determine if and how POCD manifests itself. We argue that, for pre-clinical and clinical research of POCD to advance, the effects of surgery on various cognitive functions and brain areas should be studied. Moreover, in addition to general characteristics, research should take inter-relationships between cognitive complaints and physical and mental characteristics into account. Copyright © 2012 Elsevier Inc. All rights reserved.

The Devil Is in the Details: Incomplete Reporting in Preclinical Animal Research.

Science.gov (United States)

Avey, Marc T; Moher, David; Sullivan, Katrina J; Fergusson, Dean; Griffin, Gilly; Grimshaw, Jeremy M; Hutton, Brian; Lalu, Manoj M; Macleod, Malcolm; Marshall, John; Mei, Shirley H J; Rudnicki, Michael; Stewart, Duncan J; Turgeon, Alexis F; McIntyre, Lauralyn

2016-01-01

Incomplete reporting of study methods and results has become a focal point for failures in the reproducibility and translation of findings from preclinical research. Here we demonstrate that incomplete reporting of preclinical research is not limited to a few elements of research design, but rather is a broader problem that extends to the reporting of the methods and results. We evaluated 47 preclinical research studies from a systematic review of acute lung injury that use mesenchymal stem cells (MSCs) as a treatment. We operationalized the ARRIVE (Animal Research: Reporting of In Vivo Experiments) reporting guidelines for pre-clinical studies into 109 discrete reporting sub-items and extracted 5,123 data elements. Overall, studies reported less than half (47%) of all sub-items (median 51 items; range 37-64). Across all studies, the Methods Section reported less than half (45%) and the Results Section reported less than a third (29%). There was no association between journal impact factor and completeness of reporting, which suggests that incomplete reporting of preclinical research occurs across all journals regardless of their perceived prestige. Incomplete reporting of methods and results will impede attempts to replicate research findings and maximize the value of preclinical studies.

Preclinical Alzheimer's disease: Definition, natural history, and diagnostic criteria.

Science.gov (United States)

Dubois, Bruno; Hampel, Harald; Feldman, Howard H; Scheltens, Philip; Aisen, Paul; Andrieu, Sandrine; Bakardjian, Hovagim; Benali, Habib; Bertram, Lars; Blennow, Kaj; Broich, Karl; Cavedo, Enrica; Crutch, Sebastian; Dartigues, Jean-François; Duyckaerts, Charles; Epelbaum, Stéphane; Frisoni, Giovanni B; Gauthier, Serge; Genthon, Remy; Gouw, Alida A; Habert, Marie-Odile; Holtzman, David M; Kivipelto, Miia; Lista, Simone; Molinuevo, José-Luis; O'Bryant, Sid E; Rabinovici, Gil D; Rowe, Christopher; Salloway, Stephen; Schneider, Lon S; Sperling, Reisa; Teichmann, Marc; Carrillo, Maria C; Cummings, Jeffrey; Jack, Cliff R

2016-03-01

During the past decade, a conceptual shift occurred in the field of Alzheimer's disease (AD) considering the disease as a continuum. Thanks to evolving biomarker research and substantial discoveries, it is now possible to identify the disease even at the preclinical stage before the occurrence of the first clinical symptoms. This preclinical stage of AD has become a major research focus as the field postulates that early intervention may offer the best chance of therapeutic success. To date, very little evidence is established on this "silent" stage of the disease. A clarification is needed about the definitions and lexicon, the limits, the natural history, the markers of progression, and the ethical consequence of detecting the disease at this asymptomatic stage. This article is aimed at addressing all the different issues by providing for each of them an updated review of the literature and evidence, with practical recommendations. Copyright © 2016 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Use of Preclinical Drug vs. Food Choice Procedures to Evaluate Candidate Medications for Cocaine Addiction.

Science.gov (United States)

Banks, Matthew L; Hutsell, Blake A; Schwienteck, Kathryn L; Negus, S Stevens

2015-06-01

Drug addiction is a disease that manifests as an inappropriate allocation of behavior towards the procurement and use of the abused substance and away from other behaviors that produce more adaptive reinforcers (e.g. exercise, work, family and social relationships). The goal of treating drug addiction is not only to decrease drug-maintained behaviors, but also to promote a reallocation of behavior towards alternative, nondrug reinforcers. Experimental procedures that offer concurrent access to both a drug reinforcer and an alternative, nondrug reinforcer provide a research tool for assessment of medication effects on drug choice and behavioral allocation. Choice procedures are currently the standard in human laboratory research on medications development. Preclinical choice procedures have been utilized in biomedical research since the early 1940's, and during the last 10-15 years, their use for evaluation of medications to treat drug addiction has increased. We propose here that parallel use of choice procedures in preclinical and clinical studies will facilitate translational research on development of medications to treat cocaine addiction. In support of this proposition, a review of the literature suggests strong concordance between preclinical effectiveness of candidate medications to modify cocaine choice in nonhuman primates and rodents and clinical effectiveness of these medications to modify either cocaine choice in human laboratory studies or metrics of cocaine abuse in patients with cocaine use disorder. The strongest evidence for medication effectiveness in preclinical choice studies has been obtained with maintenance on the monoamine releaser d -amphetamine, a candidate agonist medication for cocaine use analogous to use of methadone to treat heroin abuse or nicotine formulations to treat tobacco dependence.

Modeling the Western Diet for Preclinical Investigations.

Science.gov (United States)

Hintze, Korry J; Benninghoff, Abby D; Cho, Clara E; Ward, Robert E

2018-05-01

Rodent models have been invaluable for biomedical research. Preclinical investigations with rodents allow researchers to investigate diseases by using study designs that are not suitable for human subjects. The primary criticism of preclinical animal models is that results are not always translatable to humans. Some of this lack of translation is due to inherent differences between species. However, rodent models have been refined over time, and translatability to humans has improved. Transgenic animals have greatly aided our understanding of interactions between genes and disease and have narrowed the translation gap between humans and model animals. Despite the technological innovations of animal models through advances in genetics, relatively little attention has been given to animal diets. Namely, developing diets that replicate what humans eat will help make animal models more relevant to human populations. This review focuses on commonly used rodent diets that are used to emulate the Western dietary pattern in preclinical studies of obesity and type 2 diabetes, nonalcoholic liver disease, maternal nutrition, and colorectal cancer.

The Devil Is in the Details: Incomplete Reporting in Preclinical Animal Research.

Directory of Open Access Journals (Sweden)

Marc T Avey

Full Text Available Incomplete reporting of study methods and results has become a focal point for failures in the reproducibility and translation of findings from preclinical research. Here we demonstrate that incomplete reporting of preclinical research is not limited to a few elements of research design, but rather is a broader problem that extends to the reporting of the methods and results. We evaluated 47 preclinical research studies from a systematic review of acute lung injury that use mesenchymal stem cells (MSCs as a treatment. We operationalized the ARRIVE (Animal Research: Reporting of In Vivo Experiments reporting guidelines for pre-clinical studies into 109 discrete reporting sub-items and extracted 5,123 data elements. Overall, studies reported less than half (47% of all sub-items (median 51 items; range 37-64. Across all studies, the Methods Section reported less than half (45% and the Results Section reported less than a third (29%. There was no association between journal impact factor and completeness of reporting, which suggests that incomplete reporting of preclinical research occurs across all journals regardless of their perceived prestige. Incomplete reporting of methods and results will impede attempts to replicate research findings and maximize the value of preclinical studies.

Degenerated human articular cartilage at autopsy represents preclinical osteoarthritic cartilage: comparison with clinically defined osteoarthritic cartilage

NARCIS (Netherlands)

van Valburg, A. A.; Wenting, M. J.; Beekman, B.; te Koppele, J. M.; Lafeber, F. P.; Bijlsma, J. W.

1997-01-01

To investigate whether macroscopically fibrillated human articular knee cartilage observed at autopsy can be considered an early, preclinical phase of osteoarthritis (OA). Histological and biochemical characteristics of 3 types of articular knee cartilage were compared: macroscopically degenerated

PP22. PROGRESSING RADIOTHERAPY-DRUG COMBINATIONS TOWARDS EARLY PHASE CLINICAL TRIALS

Science.gov (United States)

Jones, Dr Hazel; Stock, Dr Julie; Chalmers, Prof Anthony

2017-01-01

Abstract The Radiotherapy-Drug Combinations consortium (RaDCom) works with UK-based investigators to design and deliver high quality preclinical projects evaluating specific radiotherapy-drug combinations. We have several collaborations with industry, from in vitro projects to understand the novel agent in the context of radiobiology, through to preclinical studies that will generate data to support the development of radiotherapy combination trials. RaDCom facilitates the coordination of industry interactions, triage new proposals, monitor active projects, and engages with the radiotherapy community to promote collaboration and networking (via a capability map). The CRUK New Agents Committee Preclinical Combination Grant scheme provides one of the funding options for these studies, with the potential to feed into early phase clinical trials via the ECMC Combinations Alliance. RaDCom also supports broader radiotherapy research initiatives, by working to improve preclinical quality assurance and identifying a route to registration for radiotherapy-drug treatments. These activities will place the UK at the forefront of radiotherapy-drug preclinical research and provide a significant incentive for pharmaceutical companies to invest in this area and utilise the RaDCom network. Further information can be found on our webpage: http://ctrad.ncri.org.uk/research-support/radiation-drug-combinations-radcom Successful projects from RaDCom can then move into early phase combinations trials within the Combinations Alliance. The Combinations Alliance supports early phase combination studies in the UK via the ECMC (Experimental Cancer Medicine Centres) network. It focuses on translational research, and enables clinical project teams to work with disease experts to set up investigator led trials. The CRUK Centre of Drug Development (CDD) supports these studies with further management and coordination ensuring more robust timelines and delivery. The Combinations Alliance framework

Harmonization in preclinical epilepsy research: A joint AES/ILAE translational initiative.

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Galanopoulou, Aristea S; French, Jacqueline A; O'Brien, Terence; Simonato, Michele

2017-11-01

Among the priority next steps outlined during the first translational epilepsy research workshop in London, United Kingdom (2012), jointly organized by the American Epilepsy Society (AES) and the International League Against Epilepsy (ILAE), are the harmonization of research practices used in preclinical studies and the development of infrastructure that facilitates multicenter preclinical studies. The AES/ILAE Translational Task Force of the ILAE has been pursuing initiatives that advance these goals. In this supplement, we present the first reports of the working groups of the Task Force that aim to improve practices of performing rodent video-electroencephalography (vEEG) studies in experimental controls, generate systematic reviews of preclinical research data, and develop preclinical common data elements (CDEs) for epilepsy research in animals. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Biological basis of sex differences in drug abuse: preclinical and clinical studies.

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Lynch, Wendy J; Roth, Megan E; Carroll, Marilyn E

2002-11-01

The recent focus on drug abuse in women has brought attention to numerous differences between women and men. In this review, we discuss both preclinical and clinical findings of sex differences in drug abuse as well as mechanisms that may underlie these differences. Recent evidence suggests that the progression to dependence and abuse may differ between women and men; thus, different prevention and treatment strategies may be required. Similar sex differences in drug sensitivity and self-administration have been reported in laboratory animal studies. Females appear to be more vulnerable than males to the reinforcing effects of psychostimulants, opiates, and nicotine during many phases of the addiction process (e.g. acquisition, maintenance, dysregulation-escalation, relapse). Male and female animals differ in their behavioral, neurological, and pharmacological responses to drugs. Although the role of sex in the mechanisms of drug action remains unclear, preclinical and clinical studies indicate that ovarian hormones, particularly estrogen, play a role in producing sex differences in drug abuse. Future research is necessary to provide information on how to design more effective drug abuse treatment programs and resources that are sex specific.

The basics of preclinical drug development for neurodegenerative disease indications.

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Steinmetz, Karen L; Spack, Edward G

2009-06-12

Preclinical development encompasses the activities that link drug discovery in the laboratory to initiation of human clinical trials. Preclinical studies can be designed to identify a lead candidate from several hits; develop the best procedure for new drug scale-up; select the best formulation; determine the route, frequency, and duration of exposure; and ultimately support the intended clinical trial design. The details of each preclinical development package can vary, but all have some common features. Rodent and nonrodent mammalian models are used to delineate the pharmacokinetic profile and general safety, as well as to identify toxicity patterns. One or more species may be used to determine the drug's mean residence time in the body, which depends on inherent absorption, distribution, metabolism, and excretion properties. For drugs intended to treat Alzheimer's disease or other brain-targeted diseases, the ability of a drug to cross the blood brain barrier may be a key issue. Toxicology and safety studies identify potential target organs for adverse effects and define the Therapeutic Index to set the initial starting doses in clinical trials. Pivotal preclinical safety studies generally require regulatory oversight as defined by US Food and Drug Administration (FDA) Good Laboratory Practices and international guidelines, including the International Conference on Harmonization. Concurrent preclinical development activities include developing the Clinical Plan and preparing the new drug product, including the associated documentation to meet stringent FDA Good Manufacturing Practices regulatory guidelines. A wide range of commercial and government contract options are available for investigators seeking to advance their candidate(s). Government programs such as the Small Business Innovative Research and Small Business Technology Transfer grants and the National Institutes of Health Rapid Access to Interventional Development Pilot Program provide funding and

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

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Valerie C Henderson

Full Text Available 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.

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

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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.

A systematic review of methodology applied during preclinical anesthetic neurotoxicity studies: important issues and lessons relevant to the design of future clinical research.

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Disma, Nicola; Mondardini, Maria C; Terrando, Niccolò; Absalom, Anthony R; Bilotta, Federico

2016-01-01

Preclinical evidence suggests that anesthetic agents harm the developing brain thereby causing long-term neurocognitive impairments. It is not clear if these findings apply to humans, and retrospective epidemiological studies thus far have failed to show definitive evidence that anesthetic agents are harmful to the developing human brain. The aim of this systematic review was to summarize the preclinical studies published over the past decade, with a focus on methodological issues, to facilitate the comparison between different preclinical studies and inform better design of future trials. The literature search identified 941 articles related to the topic of neurotoxicity. As the primary aim of this systematic review was to compare methodologies applied in animal studies to inform future trials, we excluded a priori all articles focused on putative mechanism of neurotoxicity and the neuroprotective agents. Forty-seven preclinical studies were finally included in this review. Methods used in these studies were highly heterogeneous-animals were exposed to anesthetic agents at different developmental stages, in various doses and in various combinations with other drugs, and overall showed diverse toxicity profiles. Physiological monitoring and maintenance of physiological homeostasis was variable and the use of cognitive tests was generally limited to assessment of specific brain areas, with restricted translational relevance to humans. Comparison between studies is thus complicated by this heterogeneous methodology and the relevance of the combined body of literature to humans remains uncertain. Future preclinical studies should use better standardized methodologies to facilitate transferability of findings from preclinical into clinical science. © 2015 John Wiley & Sons Ltd.

Thymoquinone as a Potential Adjuvant Therapy for Cancer Treatment: Evidence from Preclinical Studies

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A.G.M. Mostofa

2017-06-01

Full Text Available Thymoquinone (TQ, the main bioactive component of Nigella sativa, has been found to exhibit anticancer effects in numerous preclinical studies. Due to its multitargeting nature, TQ interferes in a wide range of tumorigenic processes and counteracts carcinogenesis, malignant growth, invasion, migration, and angiogenesis. Moreover, TQ can specifically sensitize tumor cells toward conventional cancer treatments (e.g., radiotherapy, chemotherapy, and immunotherapy and simultaneously minimize therapy-associated toxic effects in normal cells. In this review, we summarized the adjuvant potential of TQ as observed in various in vitro and in vivo animal models and discussed the pharmacological properties of TQ to rationalize its supplementary role in potentiating the efficacy of standard therapeutic modalities namely surgery, radiotherapy, chemotherapy, and immunotherapy. Altogether, we suggest further comprehensive evaluation of TQ in preclinical and clinical levels to delineate its implied utility as a novel complementary adjuvant therapy for cancer treatment.

Preclinical Murine Models for Lung Cancer: Clinical Trial Applications

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Amelia Kellar

2015-01-01

Full Text Available Murine models for the study of lung cancer have historically been the backbone of preliminary preclinical data to support early human clinical trials. However, the availability of multiple experimental systems leads to debate concerning which model, if any, is best suited for a particular therapeutic strategy. It is imperative that these models accurately predict clinical benefit of therapy. This review provides an overview of the current murine models used to study lung cancer and the advantages and limitations of each model, as well as a retrospective evaluation of the uses of each model with respect to accuracy in predicting clinical benefit of therapy. A better understanding of murine models and their uses, as well as their limitations may aid future research concerning the development and implementation of new targeted therapies and chemotherapeutic agents for lung cancer.

Successful Object Encoding Induces Increased Directed Connectivity in Presymptomatic Early-Onset Alzheimer’s Disease

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Ochoa, John Fredy; Alonso, Joan Francesc; Duque, Jon Edinson; Tobón, Carlos Andrés; Mañanas, Miguel Angel; Lopera, Francisco; Hernández, Alher Mauricio

2016-01-01

Background: Recent studies report increases in neural activity in brain regions critical to episodic memory at preclinical stages of Alzheimer’s disease (AD). Although electroencephalography (EEG) is widely used in AD studies, given its non-invasiveness and low cost, there is a need to translate the findings in other neuroimaging methods to EEG. Objective: To examine how the previous findings using functional magnetic resonance imaging (fMRI) at preclinical stage in presenilin-1 E280A mutation carriers could be assessed and extended, using EEG and a connectivity approach. Methods: EEG signals were acquired during resting and encoding in 30 normal cognitive young subjects, from an autosomal dominant early-onset AD kindred from Antioquia, Colombia. Regions of the brain previously reported as hyperactive were used for connectivity analysis. Results: Mutation carriers exhibited increasing connectivity at analyzed regions. Among them, the right precuneus exhibited the highest changes in connectivity. Conclusion: Increased connectivity in hyperactive cerebral regions is seen in individuals, genetically-determined to develop AD, at preclinical stage. The use of a connectivity approach and a widely available neuroimaging technique opens the possibility to increase the use of EEG in early detection of preclinical AD. PMID:27792014

The Flipped Classroom for pre-clinical dental skills teaching - a reflective commentary.

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Crothers, A J; Bagg, J; McKerlie, R

2017-05-12

A Flipped Classroom method for teaching of adult practical pre-clinical dental skills was introduced to the BDS curriculum in Glasgow during the 2015/2016 academic session. This report provides a commentary of the first year of employing this method - from the identification of the need to optimise teaching resources, through the planning, implementation and development of the method, with an early indication of performance.

The basics of preclinical drug development for neurodegenerative disease indications

Directory of Open Access Journals (Sweden)

Spack Edward G

2009-06-01

Full Text Available Abstract Preclinical development encompasses the activities that link drug discovery in the laboratory to initiation of human clinical trials. Preclinical studies can be designed to identify a lead candidate from several hits; develop the best procedure for new drug scale-up; select the best formulation; determine the route, frequency, and duration of exposure; and ultimately support the intended clinical trial design. The details of each preclinical development package can vary, but all have some common features. Rodent and nonrodent mammalian models are used to delineate the pharmacokinetic profile and general safety, as well as to identify toxicity patterns. One or more species may be used to determine the drug's mean residence time in the body, which depends on inherent absorption, distribution, metabolism, and excretion properties. For drugs intended to treat Alzheimer's disease or other brain-targeted diseases, the ability of a drug to cross the blood brain barrier may be a key issue. Toxicology and safety studies identify potential target organs for adverse effects and define the Therapeutic Index to set the initial starting doses in clinical trials. Pivotal preclinical safety studies generally require regulatory oversight as defined by US Food and Drug Administration (FDA Good Laboratory Practices and international guidelines, including the International Conference on Harmonisation. Concurrent preclinical development activities include developing the Clinical Plan and preparing the new drug product, including the associated documentation to meet stringent FDA Good Manufacturing Practices regulatory guidelines. A wide range of commercial and government contract options are available for investigators seeking to advance their candidate(s. Government programs such as the Small Business Innovative Research and Small Business Technology Transfer grants and the National Institutes of Health Rapid Access to Interventional Development Pilot

Evolution of strategies to improve preclinical cardiac safety testing.

Science.gov (United States)

Gintant, Gary; Sager, Philip T; Stockbridge, Norman

2016-07-01

The early and efficient assessment of cardiac safety liabilities is essential to confidently advance novel drug candidates. This article discusses evolving mechanistically based preclinical strategies for detecting drug-induced electrophysiological and structural cardiotoxicity using in vitro human ion channel assays, human-based in silico reconstructions and human stem cell-derived cardiomyocytes. These strategies represent a paradigm shift from current approaches, which rely on simplistic in vitro assays that measure blockade of the Kv11.1 current (also known as the hERG current or IKr) and on the use of non-human cells or tissues. These new strategies have the potential to improve sensitivity and specificity in the early detection of genuine cardiotoxicity risks, thereby reducing the likelihood of mistakenly discarding viable drug candidates and speeding the progression of worthy drugs into clinical trials.

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

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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

Resistance vs resilience to Alzheimer disease: Clarifying terminology for preclinical studies.

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Arenaza-Urquijo, Eider M; Vemuri, Prashanthi

2018-04-10

Preventing or delaying Alzheimer disease (AD) through lifestyle interventions will come from a better understanding of the mechanistic underpinnings of (1) why a significant proportion of elderly remain cognitively normal with AD pathologies (ADP), i.e., amyloid or tau; and (2) why some elderly individuals do not have significant ADP. In the last decades, concepts such as brain reserve, cognitive reserve, and more recently brain maintenance have been proposed along with more general notions such as (neuro)protection and compensation. It is currently unclear how to effectively apply these concepts in the new field of preclinical AD specifically separating the 2 distinct mechanisms of coping with pathology vs avoiding pathology. We propose a simplistic conceptual framework that builds on existing concepts using the nomenclature of resistance in the context of avoiding pathology, i.e., remaining cognitively normal without significant ADP, and resilience in the context of coping with pathology, i.e., remaining cognitively normal despite significant ADP. In the context of preclinical AD studies, we (1) define these concepts and provide recommendations (and common scenarios) for their use; (2) discuss how to employ this terminology in the context of investigating mechanisms and factors; (3) highlight the complementarity and clarity they provide to existing concepts; and (4) discuss different study designs and methodologies. The application of the proposed framework for framing hypotheses, study design, and interpretation of results and mechanisms can provide a consistent framework and nomenclature for researchers to reach consensus on identifying factors that may prevent ADP or delay the onset of cognitive impairment. © 2018 American Academy of Neurology.

The role of the time-kill kinetics assay as part of a preclinical modeling framework for assessing the activity of anti-tuberculosis drugs.

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Bax, Hannelore I; Bakker-Woudenberg, Irma A J M; de Vogel, Corné P; van der Meijden, Aart; Verbon, Annelies; de Steenwinkel, Jurriaan E M

2017-07-01

Novel treatment strategies for tuberculosis are urgently needed. Many different preclinical models assessing anti-tuberculosis drug activity are available, but it is yet unclear which combination of models is most predictive of clinical treatment efficacy. The aim of this study was to determine the role of our in vitro time kill-kinetics assay as an asset to a predictive preclinical modeling framework assessing anti-tuberculosis drug activity. The concentration- and time-dependent mycobacterial killing capacities of six anti-tuberculosis drugs were determined during exposure as single drugs or in dual, triple and quadruple combinations towards a Mycobacterium tuberculosis Beijing genotype strain and drug resistance was assessed. Streptomycin, rifampicin and isoniazid were most active against fast-growing M. tuberculosis. Isoniazid with rifampicin or high dose ethambutol were the only synergistic drug combinations. The addition of rifampicin or streptomycin to isoniazid prevented isoniazid resistance. In vitro ranking showed agreement with early bactericidal activity in tuberculosis patients for some but not all anti-tuberculosis drugs. The time-kill kinetics assay provides important information on the mycobacterial killing dynamics of anti-tuberculosis drugs during the early phase of drug exposure. As such, this assay is a valuable component of the preclinical modeling framework. Copyright © 2017 Elsevier Ltd. All rights reserved.

Extracurricular activities associated with stress and burnout in preclinical medical students

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Jawad Fares

2016-09-01

Full Text Available This study aims to assess the prevalence of stress and burnout among preclinical medical students in a private university in Beirut, Lebanon, and evaluate the association between extracurricular involvement and stress and burnout relief in preclinical medical students. A cross-sectional survey was conducted on a random sample of 165 preclinical medical students. Distress level was measured using the 12-item General Health Questionnaire (GHQ-12 while that of burnout was measured through the Maslach Burnout Inventory-Student Survey (MBI-SS. The MBI-SS assesses three interrelated dimensions: emotional exhaustion, cynicism, and academic efficacy. Extracurricular activities were divided into four categories: physical exercise, music, reading, and social activities. All selected participants responded. A substantial proportion of preclinical medical students suffered from stress (62% and burnout (75%. Bivariate and multivariate regression analyses revealed that being a female or a 1st year medical student correlated with higher stress and burnout. Music-related activities were correlated with lower burnout. Social activities or living with parents were associated with lower academic efficacy. The high stress and burnout levels call for action. Addressing the studying conditions and attending to the psychological wellbeing of preclinical medical students are recommendations made in the study.

Extracurricular activities associated with stress and burnout in preclinical medical students.

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Fares, Jawad; Saadeddin, Zein; Al Tabosh, Hayat; Aridi, Hussam; El Mouhayyar, Christopher; Koleilat, Mohamad Karim; Chaaya, Monique; El Asmar, Khalil

2016-09-01

This study aims to assess the prevalence of stress and burnout among preclinical medical students in a private university in Beirut, Lebanon, and evaluate the association between extracurricular involvement and stress and burnout relief in preclinical medical students. A cross-sectional survey was conducted on a random sample of 165 preclinical medical students. Distress level was measured using the 12-item General Health Questionnaire (GHQ-12) while that of burnout was measured through the Maslach Burnout Inventory-Student Survey (MBI-SS). The MBI-SS assesses three interrelated dimensions: emotional exhaustion, cynicism, and academic efficacy. Extracurricular activities were divided into four categories: physical exercise, music, reading, and social activities. All selected participants responded. A substantial proportion of preclinical medical students suffered from stress (62%) and burnout (75%). Bivariate and multivariate regression analyses revealed that being a female or a 1st year medical student correlated with higher stress and burnout. Music-related activities were correlated with lower burnout. Social activities or living with parents were associated with lower academic efficacy. The high stress and burnout levels call for action. Addressing the studying conditions and attending to the psychological wellbeing of preclinical medical students are recommendations made in the study. Copyright © 2015 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

Analysis of machine perfusion benefits in kidney grafts: a preclinical study

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Eugene Michel

2011-01-01

Full Text Available Abstract Background Machine perfusion (MP has potential benefits for marginal organs such as from deceased from cardiac death donors (DCD. However, there is still no consensus on MP benefits. We aimed to determine machine perfusion benefits on kidney grafts. Methods We evaluated kidney grafts preserved in ViaspanUW or KPS solutions either by CS or MP, in a DCD pig model (60 min warm ischemia + 24 h hypothermic preservation. Endpoints were: function recovery, quality of function during follow up (3 month, inflammation, fibrosis, animal survival. Results ViaspanUW-CS animals did not recover function, while in other groups early follow up showed similar values for kidney function. Alanine peptidase and β-NAG activities in the urine were higher in CS than in MP groups. Oxydative stress was lower in KPS-MP animals. Histology was improved by MP over CS. Survival was 0% in ViaspanUW-CS and 60% in other groups. Chronic inflammation, epithelial-to-mesenchymal transition and fibrosis were lowest in KPS-MP, followed by KPS-CS and ViaspanUW-MP. Conclusions With ViaspanUW, effects of MP are obvious as only MP kidney recovered function and allowed survival. With KPS, the benefits of MP over CS are not directly obvious in the early follow up period and only histological analysis, urinary tubular enzymes and red/ox status was discriminating. Chronic follow-up was more conclusive, with a clear superiority of MP over CS, independently of the solution used. KPS was proven superior to ViaspanUW in each preservation method in terms of function and outcome. In our pre-clinical animal model of DCD transplantation, MP offers critical benefits.

Impact of diet restriction in the management of diabetes: evidences from preclinical studies.

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Krishan, Pawan; Bedi, Onkar; Rani, Monika

2018-03-01

The inappropriate dietary habits lead to the onset of age-related pathologies which include diabetes and cardiovascular ailments. Dietary restriction and nutritional therapy play an important role in the prevention of these chronic ailments. Preclinical research provides a basis for the therapeutic exploration of new dietary interventions for the clinical trials to potentiate the scientific management of diabetes and its related complications which further help in translating these nutritional improvements from bench to bedside. Within the same context, numerous therapeutically proved preclinical dietary interventions like high-fiber diet, caloric restriction, soy isoflavone-containing diets, etc., have shown the promising results for the management of diabetes and the associated complications. The focus of the present review is to highlight the various preclinical evidences of diet restriction for the management of diabetes and which will be helpful for enlightening the new ideas of nutritional therapy for future research exploration. In addition, some potential approaches are also discussed which are associated with various nutritional interventions to combat progressive diabetes and the associated disorders. Graphical abstract ᅟ.

The Economics of Reproducibility in Preclinical Research.

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Leonard P Freedman

2015-06-01

Full Text Available Low reproducibility rates within life science research undermine cumulative knowledge production and contribute to both delays and costs of therapeutic drug development. An analysis of past studies indicates that the cumulative (total prevalence of irreproducible preclinical research exceeds 50%, resulting in approximately US$28,000,000,000 (US$28B/year spent on preclinical research that is not reproducible-in the United States alone. We outline a framework for solutions and a plan for long-term improvements in reproducibility rates that will help to accelerate the discovery of life-saving therapies and cures.

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

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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 compar...

Insights From Pre-Clinical and Clinical Studies on the Role of Innate Inflammation in Atherosclerosis Regression

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Karishma Rahman

2018-05-01

Full Text Available Atherosclerosis, the underlying cause of coronary artery (CAD and other cardiovascular diseases, is initiated by macrophage-mediated immune responses to lipoprotein and cholesterol accumulation in artery walls, which result in the formation of plaques. Unlike at other sites of inflammation, the immune response becomes maladaptive and inflammation fails to resolve. The most common treatment for reducing the risk from atherosclerosis is low density lipoprotein cholesterol (LDL-C lowering. Studies have shown, however, that while significant lowering of LDL-C reduces the risk of heart attacks to some degree, there is still residual risk for the majority of the population. We and others have observed “residual inflammatory risk” of atherosclerosis after plasma cholesterol lowering in pre-clinical studies, and that this phenomenon is clinically relevant has been dramatically reinforced by the recent Canakinumab Anti-inflammatory Thrombosis Outcomes Study (CANTOS trial. This review will summarize the role of the innate immune system, specifically macrophages, in atherosclerosis progression and regression, as well as the pre-clinical and clinical models that have provided significant insights into molecular pathways involved in the resolution of plaque inflammation and plaque regression. Partnered with clinical studies that can be envisioned in the post-CANTOS period, including progress in developing targeted plaque therapies, we expect that pre-clinical studies advancing on the path summarized in this review, already revealing key mechanisms, will continue to be essential contributors to achieve the goals of dampening plaque inflammation and inducing its resolution in order to maximize the therapeutic benefits of conventional risk factor modifications, such as LDL-C lowering.

Exploratory study of factors related to educational scores of first preclinical year medical students.

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

2014-03-01

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. Questionnaires were sent out to all first preclinical year medical students, with 79.8% being returned (245/307 questionnaires). Positive correlations were revealed between the premedical year grade point average (pre-MD GPA) and anatomy, physiology, and biochemistry scores (R = 0.664, 0.521, and 0.653, respectively, P student satisfaction with anatomy, the percentage of expected reading, monthly earnings, reading after class and near exam time, and duration of sleeping periods near exam time (R = 0.773, R(2) = 0.598, P student satisfaction with biochemistry, and exam performance expectations (R = 0.794, R(2) = 0.630, P satisfaction.

Microbial landscape features in patients with generalized periodontitis at pre-clinical and radiological stage of its development

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Vatamanyuk N.V.

2014-11-01

Full Text Available The paper presents the results of a comparative study of microbial landscape features in patients with generalized periodontitis at pre-clinical and radiological stage of its development in 42 patients. The purpose of the study is a comparative study of the composition of microbiocenosis of periodontal tissues in patients with chronic catarrhal gingivitis (CCG and chronic generalized periodontitis (CGP at an early stage of development and development studies of microbiological criteria for early emergence of the destructive process in periodontal structures. We found that the microflora isolated from dento-gingival grooves is of importance in diagnostics to identify the etiology of chronic generalized catarrhal gingivitis (CGCG and chronic generalized periodontitis in the early stages of its development. It was established that the presence of two or more types of fixed parodonto-pathogenic microorganisms in microbial association increases the likelihood of inflammatory and destructive events in periodontal tissues in patients with GCCG and is one of the reasons of is becoming CGP.

Accuracy of a clinical PET/CT vs. a preclinical μPET system for monitoring treatment effects in tumour xenografts

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Palmowski, Karin [Department of Experimental Molecular Imaging, RWTH-Aachen University, Aachen (Germany); Department of Pneumology and Critical Care Medicine, Thoraxklinik Heidelberg, University of Heidelberg, Heidelberg (Germany); Winz, Oliver [Department of Nuclear Medicine, RWTH-Aachen University, Aachen (Germany); Rix, Anne; Bzyl, Jessica [Department of Experimental Molecular Imaging, RWTH-Aachen University, Aachen (Germany); Behrendt, Florian F.; Verburg, Frederic A.; Mottaghy, Felix M. [Department of Nuclear Medicine, RWTH-Aachen University, Aachen (Germany); Palmowski, Moritz, E-mail: mpalmowski@ukaachen.de [Department of Experimental Molecular Imaging, RWTH-Aachen University, Aachen (Germany); Department of Nuclear Medicine, RWTH-Aachen University, Aachen (Germany); Academic Radiology Baden Baden, Diagnostic and Interventional Radiology, University Medical Center Heidelberg, Heidelberg (Germany)

2013-08-15

Purpose: Small animal imaging is of growing importance for preclinical research and drug development. Tumour xenografts implanted in mice can be visualized with a clinical PET/CT (cPET); however, it is unclear whether early treatment effects can be monitored. Thus, we investigated the accuracy of a cPET versus a preclinical μPET using {sup 18}F-FDG for assessing early treatment effects. Materials and methods: The spatial resolution and the quantitative accuracy of a clinical and preclinical PET were evaluated in phantom experiments. To investigate the sensitivity for assessing treatment response, A431 tumour xenografts were implanted in nude mice. Glucose metabolism was measured in untreated controls and in two therapy groups (either one or four days of antiangiogenic treatment). Data was validated by γ-counting of explanted tissues. Results: In phantom experiments, cPET enabled reliable separation of boreholes ≥ 5 mm whereas μPET visualized boreholes ≥ 2 mm. In animal studies, μPET provided significantly higher tumour-to-muscle ratios for untreated control tumours than cPET (3.41 ± 0.87 vs. 1.60 ± .0.28, respectively; p < 0.01). During treatment, cPET detected significant therapy effects at day 4 (p < 0.05) whereas μPET revealed highly significant therapy effects even at day one (p < 0.01). Correspondingly, γ-counting of explanted tumours indicated significant therapy effects at day one and highly significant treatment response at day 4. Correlation with γ-counting was good for cPET (r = 0.74; p < 0.01) and excellent for μPET (r = 0.85; p < 0.01). Conclusion: Clinical PET is suited to investigate tumour xenografts ≥ 5 mm at an advanced time-point of treatment. For imaging smaller tumours or for the sensitive assessment of very early therapy effects, μPET should be preferred.

Content of Diabetes-Associated Autoantibodies against Islet Autoantigens (IA-2A, GADA, IAA and the Level of Different Cytokines in Children and Adolescents on the Pre-Clinical and Early Clinical Stages of Type 1 Diabetes Mellitus Development

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V.V. Popova

2015-03-01

Full Text Available The article provides the data on the immunological mechanisms of type 1 diabetes mellitus (T1DM on the preclinical and early clinical stages of disease formation on the basis of studying the features of T1DM pathogenesis, monitoring the process of autoimmune destruction of insulin-producing β-cells by determining the content of diabetes-associated auto-antibodies (the incidence and titers dynamics, the study of the characteristics of cytokine secretion on the pre-clinical stage of T1DM development in children and adolescents. Introduction of new approaches to pre-clinical diagnosis of T1DM allowed determine the group of marker-positive children with burdened heredity and predictable risk of disease development. The study involved 450 healthy normoglycemic children and adolescents aged from 7 to 15 years old. It was revealed that 94 (26.7 % of 366 children with burdened hereditary by at least two-fold determination of DAAb had an increased DAAb titer, mainly GADA and IA-2A, the clinical debut of T1DM manifested in 49 (52.1 % of them from 6 months to 12 years (30.9 ± 3.2 months. T1DM developed in the same period in a child, that was 0.8 % of the 272 (73.3 % DAAb-negative children. There was determined a formula of combined incidence and values of simultaneously elevated DAAb titers to islet autoantigens, namely IA-2A + GADA, which are predictor of the duration of T1DM pre-clinical stage and debut occurrence. It has been also established a disturbance of cytokine production (increased level of pro-inflammatory cytokines IL-1α, IL-6 and FNO-α, IL-8 and IL-16 while reduced concentration of IL-4 in blood plasma as a key factor in the T1DM pathogenesis that causes the debut occurrence, and aggressiveness of its course.

Feature tracking CMR reveals abnormal strain in preclinical arrhythmogenic right ventricular dysplasia/ cardiomyopathy: a multisoftware feasibility and clinical implementation study.

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Bourfiss, Mimount; Vigneault, Davis M; Aliyari Ghasebeh, Mounes; Murray, Brittney; James, Cynthia A; Tichnell, Crystal; Mohamed Hoesein, Firdaus A; Zimmerman, Stefan L; Kamel, Ihab R; Calkins, Hugh; Tandri, Harikrishna; Velthuis, Birgitta K; Bluemke, David A; Te Riele, Anneline S J M

2017-09-01

Regional right ventricular (RV) dysfunction is the hallmark of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C), but is currently only qualitatively evaluated in the clinical setting. Feature Tracking Cardiovascular Magnetic Resonance (FT-CMR) is a novel quantitative method that uses cine CMR to calculate strain values. However, most prior FT-CMR studies in ARVD/C have focused on global RV strain using different software methods, complicating implementation of FT-CMR in clinical practice. We aimed to assess the clinical value of global and regional strain using FT-CMR in ARVD/C and to determine differences between commercially available FT-CMR software packages. We analyzed cine CMR images of 110 subjects (39 overt ARVD/C [mutation+/phenotype+], 40 preclinical ARVD/C [mutation+/phenotype-] and 31 control) for global and regional (subtricuspid, anterior, apical) RV strain in the horizontal longitudinal axis using four FT-CMR software methods (Multimodality Tissue Tracking, TomTec, Medis and Circle Cardiovascular Imaging). Intersoftware agreement was assessed using Bland Altman plots. For global strain, all methods showed reduced strain in overt ARVD/C patients compared to control subjects (p  0.275). For regional strain, overt ARVD/C patients showed reduced strain compared to control subjects in all segments which reached statistical significance in the subtricuspid region for all software methods (p < 0.037), in the anterior wall for two methods (p < 0.005) and in the apex for one method (p = 0.012). Preclinical subjects showed abnormal subtricuspid strain compared to control subjects using one of the software methods (p = 0.009). Agreement between software methods for absolute strain values was low (Intraclass Correlation Coefficient = 0.373). Despite large intersoftware variability of FT-CMR derived strain values, all four software methods distinguished overt ARVD/C patients from control subjects by both global and subtricuspid

Rigor or mortis: best practices for preclinical research in neuroscience.

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Steward, Oswald; Balice-Gordon, Rita

2014-11-05

Numerous recent reports document a lack of reproducibility of preclinical studies, raising concerns about potential lack of rigor. Examples of lack of rigor have been extensively documented and proposals for practices to improve rigor are appearing. Here, we discuss some of the details and implications of previously proposed best practices and consider some new ones, focusing on preclinical studies relevant to human neurological and psychiatric disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

Preclinical Safety Studies of Enadenotucirev, a Chimeric Group B Human-Specific Oncolytic Adenovirus

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Sam Illingworth

2017-06-01

Full Text Available Enadenotucirev is an oncolytic group B adenovirus identified by a process of bio-selection for the ability to selectively propagate in and rapidly kill carcinoma cells. It is resistant to inactivation by human blood components, potentially enabling intravenous dosing in patients with metastatic cancer. However, there are no known permissive animal models described for group B adenoviruses that could facilitate a conventional approach to preclinical safety studies. In this manuscript, we describe our tailored preclinical strategy designed to evaluate the key biological properties of enadenotucirev. As enadenotucirev does not replicate in animal cells, a panel of primary human cells was used to evaluate enadenotucirev replication selectivity in vitro, demonstrating that virus genome levels were >100-fold lower in normal cells relative to tumor cells. Acute intravenous tolerability in mice was used to assess virus particle-mediated toxicology and effects on innate immunity. These studies showed that particle toxicity could be ameliorated by dose fractionation, using an initial dose of virus to condition the host such that cytokine responses to subsequent doses were significantly attenuated. This, in turn, supported the initiation of a phase I intravenous clinical trial with a starting dose of 1 × 1010 virus particles given on days 1, 3, and 5.

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

NARCIS (Netherlands)

Versteegden, L.R.; Jonge, P. de; Hout, J. in't; Kuppevelt, T.H. van; Oosterwijk, E.; Feitz, W.F.J.; Vries, R.B.M. de; Daamen, W.F.

2017-01-01

CONTEXT: Urethra repair by tissue engineering has been extensively studied in laboratory animals and patients, but is not routinely used in clinical practice. OBJECTIVE: To systematically investigate preclinical and clinical evidence of the efficacy of tissue engineering for urethra repair in order

Characterization of novel preclinical dose distributions for micro irradiator

International Nuclear Information System (INIS)

Kodra, J; Miles, D; Yoon, S W; Kirsch, D G; Oldham, M

2017-01-01

This work explores and demonstrates the feasibility of utilizing new 3D printing techniques to implement advanced micro radiation therapy for pre-clinical small animal studies. 3D printed blocks and compensators were designed and printed from a strong x-ray attenuating material at sub-millimeter resolution. These techniques enable a powerful range of new preclinical treatment capabilities including grid therapy, lattice therapy, and IMRT treatment. At small scales, verification of these treatments is exceptionally challenging, and high resolution 3D dosimetry (0.5mm 3 ) is an essential capability to characterize and verify these capabilities, Here, investigate the 2D and 3D dosimetry of several novel pre-clinical treatments using a combination of EBT film and Presage/optical-CT 3D dosimetry in rodent-morphic dosimeters. (paper)

Characterization of novel preclinical dose distributions for micro irradiator

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Kodra, J.; Miles, D.; Yoon, S. W.; Kirsch, D. G.; Oldham, M.

2017-05-01

This work explores and demonstrates the feasibility of utilizing new 3D printing techniques to implement advanced micro radiation therapy for pre-clinical small animal studies. 3D printed blocks and compensators were designed and printed from a strong x-ray attenuating material at sub-millimeter resolution. These techniques enable a powerful range of new preclinical treatment capabilities including grid therapy, lattice therapy, and IMRT treatment. At small scales, verification of these treatments is exceptionally challenging, and high resolution 3D dosimetry (0.5mm3) is an essential capability to characterize and verify these capabilities, Here, investigate the 2D and 3D dosimetry of several novel pre-clinical treatments using a combination of EBT film and Presage/optical-CT 3D dosimetry in rodent-morphic dosimeters.

Preclinical models in radiation oncology

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Kahn Jenna

2012-12-01

Full Text Available Abstract As the incidence of cancer continues to rise, the use of radiotherapy has emerged as a leading treatment modality. Preclinical models in radiation oncology are essential tools for cancer research and therapeutics. Various model systems have been used to test radiation therapy, including in vitro cell culture assays as well as in vivo ectopic and orthotopic xenograft models. This review aims to describe such models, their advantages and disadvantages, particularly as they have been employed in the discovery of molecular targets for tumor radiosensitization. Ultimately, any model system must be judged by its utility in developing more effective cancer therapies, which is in turn dependent on its ability to simulate the biology of tumors as they exist in situ. Although every model has its limitations, each has played a significant role in preclinical testing. Continued advances in preclinical models will allow for the identification and application of targets for radiation in the clinic.

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

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Christiane Broichhausen

2014-01-01

Full Text Available 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.

Deep Machine Learning Application to the Detection of Preclinical Neurodegenerative Diseases of Aging

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Mathew J. Summers

2017-12-01

Full Text Available Artificial intelligence (AI deep learning protocols offer solutions to complex data processing and analysis. Increasingly these solutions are being applied in the healthcare field, most commonly in processing complex medical imaging data used for diagnosis. Current models apply AI to screening populations of patients for markers of disease and report detection accuracy rates exceeding those of human data screening. In this paper, we explore an alternate model for AI deployment, that of monitoring and analysing an individual’s level of function over time. In adopting this approach, we propose that AI may provide highly accurate and reliable detection of preclinical disease states associated with aging-related neurodegenerative diseases. One of the key challenges facing clinical detection of preclinical phases of diseases such as dementia is the high degree of inter-individual variability in aging-related changes to cognitive function. AI based monitoring of an individual over time offers the potential for the early detection of change in function for the individual, rather than relying on comparing the individual’s performance to population norms. We explore an approach to developing AI platforms for individual monitoring and preclinical disease detection and examine the potential benefits to the stakeholders in this technological development.

Genetic modification of risk assessment based on staging of preclinical type 1 diabetes in siblings of affected children.

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Mrena, S; Savola, K; Kulmala, P; Reijonen, H; Ilonen, J; Akerblom, H K; Knip, M

2003-06-01

We set out to study the association between human leukocyte antigen-defined genetic disease susceptibility and the stage of preclinical type 1 diabetes and whether genetic predisposition affects the natural course of preclinical diabetes in initially nondiabetic siblings of affected children. A total of 701 initially unaffected siblings were graded into four stages of preclinical type 1 diabetes based on the initial number of disease-associated autoantibodies detectable close to the time of diagnosis of the index case: no prediabetes (no antibodies), early (one antibody specificity), advanced (two antibodies), and late prediabetes (three or more antibodies). Another classification system covering 659 siblings was based on a combination of the initial number of antibodies and the first-phase insulin response (FPIR) to iv glucose: no prediabetes (no antibodies), early (one antibody specificity, normal FPIR), advanced (two or more antibodies, normal FPIR), and late prediabetes (at least one antibody, reduced FPIR). Genetic susceptibility to type 1 diabetes was defined by human leukocyte antigen identity and DR and DQ genotypes. There was a higher proportion of siblings with late prediabetes initially among those with strong genetic disease susceptibility than among those with decreased genetic predisposition (16.7% vs. 0.5%; P siblings with no signs of prediabetes among those with genotypes conferring decreased risk (91.2% vs. 70.4% among those with high-risk DQB1 genotypes; P siblings than when combined with genetic susceptibility. Genetic susceptibility played a role in whether the initial prediabetic stage progressed (progression in 29.6% of the high-risk siblings compared with 6.6% of the siblings with DQB1 genotypes conferring decreased risk; P siblings of affected children.

Stress, Burnout and Coping Strategies in Preclinical Medical Students

Science.gov (United States)

Fares, Jawad; Al Tabosh, Hayat; Saadeddin, Zein; El Mouhayyar, Christopher; Aridi, Hussam

2016-01-01

It is acknowledged that physicians do not seek the same expert aid for themselves as they would offer their patients. In their preclinical years, medical students appear to espouse comparable behavior. To many, medicine is described as a never-ending path that places the student under heavy stress and burnout from the beginning, leaving him/her vulnerable and with insufficient coping methods. Hence, the objective of this study is to 1) explore the prevalence of stress and burnout among preclinical medical students, and 2) propose solutions to decrease stress and burnout and improve medical education in the preclinical years. A detailed scholarly research strategy using Google Scholar, Scopus, Embase, MEDLINE and PubMed was implemented to highlight key themes that are relevant to preclinical medical students’ stress and burnout. Stress varied among different samples of medical students and ranged between 20.9% and 90%. Conversely, burnout ranged between 27% and 75%. Methods that help in reducing the incidence of stress and burnout by promoting strategies that focus on personal engagement, extracurricular activities, positive reinterpretation and expression of emotion, student-led mentorship programs, evaluation systems, career counseling and life coaching should be adopted. PMID:27042604

Stress, Burnout and Coping Strategies in Preclinical Medical Students.

Science.gov (United States)

Fares, Jawad; Al Tabosh, Hayat; Saadeddin, Zein; El Mouhayyar, Christopher; Aridi, Hussam

2016-02-01

It is acknowledged that physicians do not seek the same expert aid for themselves as they would offer their patients. In their preclinical years, medical students appear to espouse comparable behavior. To many, medicine is described as a never-ending path that places the student under heavy stress and burnout from the beginning, leaving him/her vulnerable and with insufficient coping methods. Hence, the objective of this study is to 1) explore the prevalence of stress and burnout among preclinical medical students, and 2) propose solutions to decrease stress and burnout and improve medical education in the preclinical years. A detailed scholarly research strategy using Google Scholar, Scopus, Embase, MEDLINE and PubMed was implemented to highlight key themes that are relevant to preclinical medical students' stress and burnout. Stress varied among different samples of medical students and ranged between 20.9% and 90%. Conversely, burnout ranged between 27% and 75%. Methods that help in reducing the incidence of stress and burnout by promoting strategies that focus on personal engagement, extracurricular activities, positive reinterpretation and expression of emotion, student-led mentorship programs, evaluation systems, career counseling and life coaching should be adopted.

Strain Analysis in the Assessment of a Mouse Model of Cardiotoxicity due to Chemotherapy: Sample for Preclinical Research.

Science.gov (United States)

Rea, Domenica; Coppola, Carmela; Barbieri, Antonio; Monti, Maria Gaia; Misso, Gabriella; Palma, Giuseppe; Bimonte, Sabrina; Zarone, Mayra Rachele; Luciano, Antonio; Liccardo, Davide; Maiolino, Piera; Cittadini, Antonio; Ciliberto, Gennaro; Arra, Claudio; Maurea, Nicola

2016-01-01

In recent years, the development of more effective anticancer drugs has provided great benefits in patients' quality of life by improving both prognosis and disease-free survival. Nevertheless, the frequency and severity of side-effects, with particular reference to cardiac toxicity, have gained particular attention. The purpose of this study was to create a precise and sensitive preclinical model, able to identify early contractile dysfunction in mice treated with chemotherapy, through use of speckle-tracking echocardiography. We generated a mouse model of cardiotoxicity induced by doxorubicin. C57BL 6 mice were divided into two groups, treated for 7 days by intraperitoneal injections of placebo (vehicle) or doxorubicin (2.17 mg/kg), in order to characterize the cardiac phenotype in vivo. We demonstrated that doxorubicin caused ealy remodeling of the left ventricle: after two days of therapy, the radial, circumferential and strain rates were reduced respectively by 35%, 34%, and 39% (p-value ≤0.001). Moreover, histological analysis revealed that doxorubicin treatment increased fibrosis, cardiomyocyte diameter and apoptosis. In a murine model of doxorubicin-induced cardiac injury, we detected left ventricular dysfunction followed by alterations in conventional echocardiographic indices. Our study suggests that a change in strain could be an effective early marker of myocardial dysfunction for new anticancer treatments and, in preclinical studies, it might also be a valuable indicator for the assessment of activity of cardioprotective agents. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Polymeric micelles for ocular drug delivery: From structural frameworks to recent preclinical studies.

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Mandal, Abhirup; Bisht, Rohit; Rupenthal, Ilva D; Mitra, Ashim K

2017-02-28

Effective intraocular drug delivery poses a major challenge due to the presence of various elimination mechanisms and physiological barriers that result in low ocular bioavailability after topical application. Over the past decades, polymeric micelles have emerged as one of the most promising drug delivery platforms for the management of ocular diseases affecting the anterior (dry eye syndrome) and posterior (age-related macular degeneration, diabetic retinopathy and glaucoma) segments of the eye. Promising preclinical efficacy results from both in-vitro and in-vivo animal studies have led to their steady progression through clinical trials. The mucoadhesive nature of these polymeric micelles results in enhanced contact with the ocular surface while their small size allows better tissue penetration. Most importantly, being highly water soluble, these polymeric micelles generate clear aqueous solutions which allows easy application in the form of eye drops without any vision interference. Enhanced stability, larger cargo capacity, non-toxicity, ease of surface modification and controlled drug release are additional advantages with polymeric micelles. Finally, simple and cost effective fabrication techniques render their industrial acceptance relatively high. This review summarizes structural frameworks, methods of preparation, physicochemical properties, patented inventions and recent advances of these micelles as effective carriers for ocular drug delivery highlighting their performance in preclinical studies. Copyright © 2017 Elsevier B.V. All rights reserved.

A review of targeted therapies evaluated by the Pediatric Preclinical Testing Program for osteosarcoma

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Valerie eSampson

2013-05-01

Full Text Available Osteosarcoma, the most common malignant bone tumor of childhood, is a high grade primary bone sarcoma that occurs mostly in adolescence. Standard treatment consists of surgery in combination with multi-agent chemotherapy regimens. The development and approval of imatinib for Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL in children and the fully human monoclonal antibody, anti-GD2, as part of an immune therapy for high-risk neuroblastoma patients have established the precedent for use of targeted inhibitors along with standard chemotherapy backbones. However, few targeted agents tested have achieved traditional clinical end points for osteosarcoma. Many biological agents demonstrating anti-tumor responses in preclinical and early phase clinical testing have failed to reach response thresholds to justify randomized trials with large numbers of patients. The development of targeted therapies for pediatric cancer remains a significant challenge. To aid in the prioritization of new agents for clinical testing, the Pediatric Preclinical Testing Program (PPTP has developed reliable and robust preclinical pediatric cancer models to rapidly screen agents for activity in multiple childhood cancers and establish pharmacological parameters and effective drug concentrations for clinical trials. In this article, we examine a range of standard and novel agents that have been evaluated by the PPTP, and we discuss the preclinical and clinical development of these for the treatment of osteosarcoma. We further demonstrate that committed resources for hypothesis-driven drug discovery and development are needed to yield clinical successes in the search for new therapies for this pediatric disease.

Platelet-rich plasma: why intra-articular? A systematic review of preclinical studies and clinical evidence on PRP for joint degeneration.

Science.gov (United States)

Filardo, G; Kon, E; Roffi, A; Di Matteo, B; Merli, M L; Marcacci, M

2015-09-01

The aim of this review was to analyze the available evidence on the clinical application of this biological approach for the injective treatment of cartilage lesions and joint degeneration, together with preclinical studies to support the rationale for the use of platelet concentrates, to shed some light and give indications on what to treat and what to expect from intra-articular injections of platelet-rich plasma (PRP). All in vitro, in vivo preclinical and clinical studies on PRP injective treatment in the English language concerning the effect of PRP on cartilage, synovial tissue, menisci, and mesenchymal stem cells were considered. A systematic review on the PubMed database was performed using the following words: (platelet-rich plasma or PRP or platelet concentrate or platelet lysate or platelet supernatant) and (cartilage or chondrocytes or synoviocytes or menisci or mesenchymal stem cells). Fifty-nine articles met the inclusion criteria: 26 were in vitro, 9 were in vivo, 2 were both in vivo and in vitro, and 22 were clinical studies. The analysis showed an increasing number of published studies over time. Preclinical evidence supports the use of PRP injections that might promote a favourable environment for joint tissues healing. Only a few high-quality clinical trials have been published, which showed a clinical improvement limited over time and mainly documented in younger patients not affected by advanced knee degeneration. Besides the limits and sometimes controversial findings, the preclinical literature shows an overall support toward this PRP application. An intra-articular injection does not just target cartilage; instead, PRP might influence the entire joint environment, leading to a short-term clinical improvement. Many biological variables might influence the clinical outcome and have to be studied to optimize PRP injective treatment of cartilage degeneration and osteoarthritis.

Digitized Spiral Drawing: A Possible Biomarker for Early Parkinson's Disease.

Science.gov (United States)

San Luciano, Marta; Wang, Cuiling; Ortega, Roberto A; Yu, Qiping; Boschung, Sarah; Soto-Valencia, Jeannie; Bressman, Susan B; Lipton, Richard B; Pullman, Seth; Saunders-Pullman, Rachel

2016-01-01

Pre-clinical markers of Parkinson's Disease (PD) are needed, and to be relevant in pre-clinical disease, they should be quantifiably abnormal in early disease as well. Handwriting is impaired early in PD and can be evaluated using computerized analysis of drawn spirals, capturing kinematic, dynamic, and spatial abnormalities and calculating indices that quantify motor performance and disability. Digitized spiral drawing correlates with motor scores and may be more sensitive in detecting early changes than subjective ratings. However, whether changes in spiral drawing are abnormal compared with controls and whether changes are detected in early PD are unknown. 138 PD subjects (50 with early PD) and 150 controls drew spirals on a digitizing tablet, generating x, y, z (pressure) data-coordinates and time. Derived indices corresponded to overall spiral execution (severity), shape and kinematic irregularity (second order smoothness, first order zero-crossing), tightness, mean speed and variability of spiral width. Linear mixed effect adjusted models comparing these indices and cross-validation were performed. Receiver operating characteristic analysis was applied to examine discriminative validity of combined indices. All indices were significantly different between PD cases and controls, except for zero-crossing. A model using all indices had high discriminative validity (sensitivity = 0.86, specificity = 0.81). Discriminative validity was maintained in patients with early PD. Spiral analysis accurately discriminates subjects with PD and early PD from controls supporting a role as a promising quantitative biomarker. Further assessment is needed to determine whether spiral changes are PD specific compared with other disorders and if present in pre-clinical PD.

Long-term impact of a preclinical endovascular skills course on medical student career choices.

Science.gov (United States)

Lee, Jason T; Son, Ji H; Chandra, Venita; Lilo, Emily; Dalman, Ronald L

2011-10-01

Surging interest in the 0 + 5 integrated vascular surgery (VS) residency and successful recruitment of the top students in medical school requires early exposure to the field. We sought to determine the impact of a high-fidelity simulation-based preclinical endovascular skills course on medical student performance and ultimate career specialty choices. Fifty-two preclinical medical students enrolled in an 8-week VS elective course from 2007 to 2009. Students completed a baseline and postcourse survey and performed a renal angioplasty/stent procedure on an endovascular simulator (pretest). A curriculum consisting of didactic teaching covering peripheral vascular disease and weekly mentored simulator sessions concluded with a final graded procedure (posttest). Long-term follow-up surveys 1 to 3 years after course completion were administered to determine ultimate career paths of participants as well as motivating factors for career choice. Objective and subjective performance measured on the simulator and through structured global assessment scales improved in all students from pre- to posttest, particularly with regard to technical skill and overall procedural competency (P choices including surgical subspecialties (64%), radiology (10%), and cardiology (6%). Most respondents indicated major reasons for continued interest in VS were the ability to practice endovascular procedures on the simulator (92%) and mentorship from VS faculty (70%). Basic endovascular skills can be efficiently introduced through a simulation-based curriculum and lead to improved novice performance. Early exposure of preclinical medical students provides an effective teaching and recruitment tool for procedural-based fields, particularly surgical subspecialties. Mentored exposure to endovascular procedures on the simulator positively impacts long-term medical student attitudes toward vascular surgery and ultimate career choices. Copyright © 2011 Society for Vascular Surgery. Published by

A quantitative analysis of statistical power identifies obesity end points for improved in vivo preclinical study design.

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Selimkhanov, J; Thompson, W C; Guo, J; Hall, K D; Musante, C J

2017-08-01

The design of well-powered in vivo preclinical studies is a key element in building the knowledge of disease physiology for the purpose of identifying and effectively testing potential antiobesity drug targets. However, as a result of the complexity of the obese phenotype, there is limited understanding of the variability within and between study animals of macroscopic end points such as food intake and body composition. This, combined with limitations inherent in the measurement of certain end points, presents challenges to study design that can have significant consequences for an antiobesity program. Here, we analyze a large, longitudinal study of mouse food intake and body composition during diet perturbation to quantify the variability and interaction of the key metabolic end points. To demonstrate how conclusions can change as a function of study size, we show that a simulated preclinical study properly powered for one end point may lead to false conclusions based on secondary end points. We then propose the guidelines for end point selection and study size estimation under different conditions to facilitate proper power calculation for a more successful in vivo study design.

Reirradiation of normal tissues: Preclinical radiobiological data; Reirradiation des tissus sains: donnees radiobiologiques precliniques

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Bourgier, C.; Vozenin, M.C.; Deutsch, E. [Departement de radiotherapie et laboratoire Upres EA2710, institut Gustave-Roussy, 94 - Villejuif (France)

2010-10-15

Reirradiation represent an unfrequent particular clinical situation. The risk/benefit ratio assessment must be taken into account, considering both clinical and dosimetric aspects. There is a relatively limited amount of preclinical data available to date and clinicians should cautiously perform re-irradiations in selected indications. This review summarizes the experimental data available on reirradiation of normal tissues, the consequences on early and late toxicities as well as the intrinsic limitations of these models. (authors)

Validation of a preclinical spinal safety model: effects of intrathecal morphine in the neonatal rat.

Science.gov (United States)

Westin, B David; Walker, Suellen M; Deumens, Ronald; Grafe, Marjorie; Yaksh, Tony L

2010-07-01

Preclinical studies demonstrate increased neuroapoptosis after general anesthesia in early life. Neuraxial techniques may minimize potential risks, but there has been no systematic evaluation of spinal analgesic safety in developmental models. We aimed to validate a preclinical model for evaluating dose-dependent efficacy, spinal cord toxicity, and long-term function after intrathecal morphine in the neonatal rat. Lumbar intrathecal injections were performed in anesthetized rats aged postnatal day (P) 3, 10, and 21. The relationship between injectate volume and segmental spread was assessed postmortem and by in vivo imaging. To determine the antinociceptive dose, mechanical withdrawal thresholds were measured at baseline and 30 min after intrathecal morphine. To evaluate toxicity, doses up to the maximum tolerated were administered, and spinal cord histopathology, apoptosis, and glial response were evaluated 1 and 7 days after P3 or P21 injection. Sensory thresholds and gait analysis were evaluated at P35. Intrathecal injection can be reliably performed at all postnatal ages and injectate volume influences segmental spread. Intrathecal morphine produced spinally mediated analgesia at all ages with lower dose requirements in younger pups. High-dose intrathecal morphine did not produce signs of spinal cord toxicity or alter long-term function. The therapeutic ratio for intrathecal morphine (toxic dose/antinociceptive dose) was at least 300 at P3 and at least 20 at P21 (latter doses limited by side effects). These data provide relative efficacy and safety for comparison with other analgesic preparations and contribute supporting evidence for the validity of this preclinical neonatal safety model.

Preclinical Data on Efficacy of 10 Drug-Radiation Combinations: Evaluations, Concerns, and Recommendations

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Helen B. Stone

2016-02-01

Full Text Available BACKGROUND: Clinical testing of new therapeutic interventions requires comprehensive, high-quality preclinical data. Concerns regarding quality of preclinical data have been raised in recent reports. This report examines the data on the interaction of 10 drugs with radiation and provides recommendations for improving the quality, reproducibility, and utility of future studies. The drugs were AZD6244, bortezomib, 17-DMAG, erlotinib, gefitinib, lapatinib, oxaliplatin/Lipoxal, sunitinib (Pfizer, Corporate headquarters, New York, NY, thalidomide, and vorinostat. METHODS: In vitro and in vivo data were tabulated from 125 published papers, including methods, radiation and drug doses, schedules of administration, assays, measures of interaction, presentation and interpretation of data, dosimetry, and conclusions. RESULTS: In many instances, the studies contained inadequate or unclear information that would hamper efforts to replicate or intercompare the studies, and that weakened the evidence for designing and conducting clinical trials. The published reports on these drugs showed mixed results on enhancement of radiation response, except for sunitinib, which was ineffective. CONCLUSIONS: There is a need for improved experimental design, execution, and reporting of preclinical testing of agents that are candidates for clinical use in combination with radiation. A checklist is provided for authors and reviewers to ensure that preclinical studies of drug-radiation combinations meet standards of design, execution, and interpretation, and report necessary information to ensure high quality and reproducibility of studies. Improved design, execution, common measures of enhancement, and consistent interpretation of preclinical studies of drug-radiation interactions will provide rational guidance for prioritizing drugs for clinical radiotherapy trials and for the design of such trials.

Preclinical electrogastrography in experimental pigs

Science.gov (United States)

Květina, Jaroslav; Varayil, Jithinraj Edakkanambeth; Ali, Shahzad Marghoob; Kuneš, Martin; Bureš, Jan; Tachecí, Ilja; Rejchrt, Stanislav; Kopáčová, Marcela

2010-01-01

Surface electrogastrography (EGG) is a non-invasive means of recording gastric myoelectric activity or slow waves from cutaneous leads placed over the stomach. This paper provides a comprehensive review of preclinical EGG. Our group recently set up and worked out the methods for EGG in experimental pigs. We gained our initial experience in the use of EGG in assessment of porcine gastric myoelectric activity after volume challenge and after intragastric administration of itopride and erythromycin. The mean dominant frequency in pigs is comparable with that found in humans. EGG in experimental pigs is feasible. Experimental EGG is an important basis for further preclinical projects in pharmacology and toxicology. PMID:21217873

[Preclinical horizon of depression in adults].

Science.gov (United States)

Jiménez-Báez, María Valeria; Márquez-González, Horacio; Monsreal-Góngora, Juan Leonardo; Góngora-González, Gonzalo; Sandoval-Jurado, Luis; Boquer-Hernández, Rubén

2016-01-01

Identify factors related to preclinical depression in healthy adults, their risk factors and concordance with family doctor diagnostic. Case-control study in adult from family medicine consulting room. Beck inventory for depression was applied. The correlation between depression and the diagnosis by the family physician was evaluated. Odds ratio (OR) was determined. Involved 138 patients randomly from four family medicine units (FMU) in the Northern Region of Quintana Roo, Mexico. The mean age 34.9 ± 11.4 years, 55.8% women, prevalence for depression was 26.1%. Being male OR: 3.76; 95% CI: 1.69-8.36, under 30 years OR: 2.76; 95% CI: 1.27-5.99, low socioeconomic status (SES) OR: 2.11; 95% CI: 0.97-4.59 and be married OR: 3.22; 95% CI: 1.41.-7.36 had depression risk. Diagnosis by the family physician and inventory Beck. Kappa Index 0.2, 95% CI: -0057-0176; p = 0.05. Almost a third of young adults have some depression degree in family medicine consulting room, it is necessary a depression screening for male patients, low SES, married, and under 30 years old, attending medical consultation familiar, for a early diagnosis and improve prognosis.

Advanced Pre-clinical Research Approaches and Models to Studying Pediatric Anesthetic Neurotoxicity

Directory of Open Access Journals (Sweden)

Cheng eWang

2012-10-01

Full Text Available Advances in pediatric and obstetric surgery have resulted in an increase in the duration and complexity of anesthetic procedures. A great deal of concern has recently arisen regarding the safety of anesthesia in infants and children. Because of obvious limitations, it is not possible to thoroughly explore the effects of anesthetic agents on neurons in vivo in human infants or children. However, the availability of some advanced pre-clinical research approaches and models, such as imaging technology both in vitro and in vivo, stem cell and nonhuman primate experimental models, have provided potentially invaluable tools for examining the developmental effects of anesthetic agents. This review discusses the potential application of some sophisticaled research approaches, e.g., calcium imaging, in stem cell-derived in vitro models, especially human embryonic neural stem cells, along with their capacity for proliferation and their potential for differentiation, to dissect relevant mechanisms underlying the etiology of the neurotoxicity associated with developmental exposures to anesthetic agents. Also, this review attempts to discuss several advantages for using the developing rhesus monkey models (in vivo, when combined with dynamic molecular imaging approaches, in addressing critical issues related to the topic of pediatric sedation/anesthesia. These include the relationships between anesthetic-induced neurotoxicity, dose response, time-course and developmental stage at time of exposure (in vivo studies, serving to provide the most expeditious platform toward decreasing the uncertainty in extrapolating pre-clinical data to the human condition.

Sex differences in the vulnerability to drug abuse: a review of preclinical studies.

Science.gov (United States)

Roth, Megan E; Cosgrove, Kelly P; Carroll, Marilyn E

2004-10-01

Clinical and preclinical findings indicate that males and females differ on several aspects of drug reinforcement. Females are more vulnerable than males during transition periods of drug use that are characteristic of drug addiction and relapse. Females are also more sensitive than males to the reinforcing effects of stimulants. It has been suggested that ovarian hormones contribute to the mechanisms of action underlying these sex differences. This review examines the preclinical literature on sex differences and ovarian hormonal influences on drug self-administration in animals. It summarizes the findings on the effects of these variables during different phases of drug addiction. Possible differences in the mechanisms of action of drugs of abuse due to interactions with sex differences or ovarian hormonal factors are considered. The animal literature on sex differences in drug abuse treatment effectiveness is also discussed.

An olfactory ‘stress test’ may detect preclinical Alzheimer’s disease

Directory of Open Access Journals (Sweden)

Schofield Peter W

2012-05-01

Full Text Available Abstract Background The olfactory bulb (OB receives extensive cholinergic input from the basal forebrain and is affected very early in Alzheimer’s disease (AD. We speculated that an olfactory ‘stress test’ (OST, targeting the OB, might be used to unmask incipient AD. We investigated if change in olfactory performance following intranasal atropine was associated with several known antecedents or biomarkers of AD. Methods We measured change in performance on the University of Pennsylvania Smell Identification Test (UPSIT in the left nostril before (20-items and after (remaining 20-items intranasal administration of 1 mg of atropine. We administered cognitive tests, measured hippocampal volume from MRI scans and recorded Apolipoprotein E genotype as indices relevant to underlying AD. Results In a convenience sample of 56 elderly individuals (14 probable AD, 13 cognitive impairment no dementia, 29 cognitively intact the change in UPSIT score after atropine (‘atropine effect’ = AE correlated significantly with demographically scaled episodic memory score (r = 0.57, p Conclusions The OST using atropine as an olfactory probe holds promise as a simple, inexpensive screen for early and preclinical AD and further work, including longitudinal studies, is needed to explore this possibility.

A Metadata Analysis of Oxidative Stress Etiology in Preclinical Amyotrophic Lateral Sclerosis: Benefits of Antioxidant Therapy

Directory of Open Access Journals (Sweden)

Leila Bond

2018-01-01

Full Text Available Oxidative stress, induced by an imbalance of free radicals, incites neurodegeneration in Amyotrophic Lateral Sclerosis (ALS. In fact, a mutation in antioxidant enzyme superoxide dismutase 1 (SOD1 accounts for 20% of familial ALS cases. However, the variance among individual studies examining ALS oxidative stress clouds corresponding conclusions. Therefore, we construct a comprehensive, temporal view of oxidative stress and corresponding antioxidant therapy in preclinical ALS by mining published quantitative experimental data and performing metadata analysis of 41 studies. In vitro aggregate analysis of innate oxidative stress inducers, glutamate and hydrogen peroxide, revealed 70–90% of cell death coincides to inducer exposure equivalent to 30–50% peak concentration (p < 0.05. A correlative plateau in cell death suggests oxidative stress impact is greatest in early-stage neurodegeneration. In vivo SOD1-G93A transgenic ALS mouse aggregate analysis of heat shock proteins (HSPs revealed HSP levels are 30% lower in muscle than spine (p < 0.1. Overall spine HSP levels, including HSP70, are mildly upregulated in SOD1-G93A mice compared to wild type, but not significantly (p > 0.05. Thus, innate HSP compensatory responses to oxidative stress are simply insufficient, a result supportive of homeostatic system instability as central to ALS etiology. In vivo aggregate analysis of antioxidant therapy finds SOD1-G93A ALS mouse survival duration significantly increases by 11.2% (p << 0.001 but insignificantly decreases onset age by 2%. Thus, the aggregate antioxidant treatment effect on survival in preclinical ALS is not sufficient to overcome clinical heterogeneity, which explains the literature disparity between preclinical and clinical antioxidant survival benefit. The aggregate effect sizes on preclinical ALS survival and onset illustrate that present antioxidants, alone, are not sufficient to halt ALS, which underscores its multi-factorial nature

Neuraxial Analgesia In Neonates And Infants: Review of Clinical and Preclinical Strategies for the Development of Safety and Efficacy Data

Science.gov (United States)

Walker, Suellen M.; Yaksh, Tony L.

2015-01-01

Neuraxial agents provide robust pain control, have the potential to improve outcomes, and are an important component of the perioperative care of children. Opioids or clonidine improve analgesia when added to perioperative epidural infusions; analgesia is significantly prolonged by addition of clonidine, ketamine, neostigmine or tramadol to single shot caudal injections of local anesthetic; and neonatal intrathecal anesthesia/analgesia is increasing in some centers. However, it is difficult to determine the relative risk-benefit of different techniques and drugs without detailed and sensitive data related to analgesia requirements, side-effects, and follow-up. Current data related to benefits and complications in neonates and infants are summarized, but variability in current neuraxial drug use reflects the relative lack of high quality evidence. Recent preclinical reports of adverse effects of general anesthetics on the developing brain have increased awareness of the potential benefit of neuraxial anesthesia/analgesia to avoid or reduce general anesthetic dose requirements. However, the developing spinal cord is also vulnerable to drug-related toxicity, and although there are well-established preclinical models and criteria for assessing spinal cord toxicity in adult animals, until recently there had been no systematic evaluation during early life. Therefore, the second half of this review presents preclinical data evaluating age-dependent changes in the pharmacodynamic response to different spinal analgesics, and recent studies evaluating spinal toxicity in specific developmental models. Finally, we advocate use of neuraxial agents with the widest demonstrable safety margin and suggest minimum standards for preclinical evaluation prior to adoption of new analgesics or preparations into routine clinical practice. PMID:22798528

Preclinical studies identify non-apoptotic low-level caspase-3 as therapeutic target in pemphigus vulgaris.

Directory of Open Access Journals (Sweden)

Camille Luyet

Full Text Available The majority of pemphigus vulgaris (PV patients suffer from a live-threatening loss of intercellular adhesion between keratinocytes (acantholysis. The disease is caused by auto-antibodies that bind to desmosomal cadherins desmoglein (Dsg 3 or Dsg3 and Dsg1 in mucous membranes and skin. A currently unresolved controversy in PV is whether apoptosis is involved in the pathogenic process. The objective of this study was to perform preclinical studies to investigate apoptotic pathway activation in PV pathogenesis with the goal to assess its potential for clinical therapy. For this purpose, we investigated mouse and human skin keratinocyte cultures treated with PV antibodies (the experimental Dsg3 monospecific antibody AK23 or PV patients IgG, PV mouse models (passive transfer of AK23 or PVIgG into adult and neonatal mice as well as PV patients' biopsies (n=6. A combination of TUNEL assay, analyses of membrane integrity, early apoptotic markers such as cleaved poly-ADP-ribose polymerase (PARP and the collapse of actin cytoskeleton failed to provide evidence for apoptosis in PV pathogenesis. However, the in vitro and in vivo PV models, allowing to monitor progression of lesion formation, revealed an early, transient and low-level caspase-3 activation. Pharmacological inhibition confirmed the functional implication of caspase-3 in major events in PV such as shedding of Dsg3, keratin retraction, proliferation including c-Myc induction, p38MAPK activation and acantholysis. Together, these data identify low-level caspase-3 activation downstream of disrupted Dsg3 trans- or cis-adhesion as a major event in PV pathogenesis that is non-synonymous with apoptosis and represents, unlike apoptotic components, a promising target for clinical therapy. At a broader level, these results posit that an impairment of adhesive functions in concert with low-level, non-lethal caspase-3 activation can evoke profound cellular changes which may be of relevance for other

Resveratrol: A review of preclinical studies for human cancer prevention

International Nuclear Information System (INIS)

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

2007-01-01

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

Working memory in early Alzheimer's disease: a neuropsychological review.

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Huntley, J D; Howard, R J

2010-02-01

Reports of the extent of working memory (WM) impairment in early Alzheimer's disease (AD) have been inconsistent. Using the model of WM proposed by Baddeley, neuropsychological evidence for the impairment of WM in early AD is evaluated. Literature searches were performed using Medline, PsycINFO and Embase databases. Individual papers were then examined for additional references not revealed by computerised searches. Phonological loop function is intact at the preclinical and early stages of AD, becoming more impaired as the disease progresses. In mild AD, there is impairment on tasks assessing visuospatial sketchpad (VSS) function; however, these tasks also require executive processing by the central executive system (CES). There is evidence that the CES is impaired in mild AD and may be affected in the earlier preclinical stage of the disease. Episodic buffer function may be impaired but further research is required. Future research into central executive functioning at the earliest stages of the disease, combined with further longitudinal studies, needs to be carried out. Tasks to assess the proposed functions of the episodic buffer and specific tests of the VSS suitable for AD subjects need to be developed and validated. Learning more about these processes and how they are affected in AD is important in understanding and managing the cognitive deficits seen in the early stages of AD.

Horizontal integration of OMIM across the medical school preclinical curriculum for early reinforcement of clinical genetics principles.

Science.gov (United States)

Diehl, Adam C; Reader, Lauren; Hamosh, Ada; Bodurtha, Joann N

2015-02-01

With the relentless expansion of genetics into every field of medicine, stronger preclinical and clinical medical student education in genetics is needed. The explosion of genetic information cannot be addressed by simply adding content hours. We proposed that students be provided a tool to access accurate clinical information on genetic conditions and, through this tool, build life-long learning habits to carry them through their medical careers. Surveys conducted at the Johns Hopkins University School of Medicine revealed that medical students in all years lacked confidence when approaching genetic conditions and lacked a reliable resource for accurate genetic information. In response, the school created a horizontal thread that stretches across the first-year curriculum and is devoted to teaching students how to use Online Mendelian Inheritance in Man (OMIM) (http://omim.org) and the databases to which it links as a starting point for approaching genetic conditions. The thread improved the first-year students' confidence in clinical genetics concepts and encouraged use of OMIM as a primary source for genetic information. Most students showed confidence in OMIM as a learning tool and wanted to see the thread repeated in subsequent years. Incorporating OMIM into the preclinical curriculum improved students' confidence in clinical genetics concepts.

Can evaluation of a dental procedure at the outset of learning predict later performance at the preclinical level? A pilot study.

LENUS (Irish Health Repository)

Polyzois, Ioannis

2011-05-01

The purpose of this study was to examine the effectiveness of conventional pre-clinical training in dentistry and to determine if evaluation of a dental procedure at the beginning of dental training can be a predictor for future performance. A group of second year dental students with no previous experience in operative dentistry were asked to prepare a conventional class I cavity on a lower first molar typodont. Their first preparation was carried out after an introductory lecture and a demonstration and their second at the end of conventional training. The prepared typodonts were coded and blindly scored for the traditional assessment criteria of outline form, retention form, smoothness, cavity depth and cavity margin angulation. Once the codes were broken, a paired t-test was used to compare the difference between the means of before and after scores (P<0.0001) and a Pearson\\'s linear correlation to test the association (r=0.4). From the results of this study, we could conclude that conventional preclinical training results in a significant improvement in the manual skills of the dental students and that the dental procedure used had only a limited predictive value for later performance at the preclinical level.

Neuraxial analgesia in neonates and infants: a review of clinical and preclinical strategies for the development of safety and efficacy data.

Science.gov (United States)

Walker, Suellen M; Yaksh, Tony L

2012-09-01

Neuraxial drugs provide robust pain control, have the potential to improve outcomes, and are an important component of the perioperative care of children. Opioids or clonidine improves analgesia when added to perioperative epidural infusions; analgesia is significantly prolonged by the addition of clonidine, ketamine, neostigmine, or tramadol to single-shot caudal injections of local anesthetic; and neonatal intrathecal anesthesia/analgesia is increasing in some centers. However, it is difficult to determine the relative risk-benefit of different techniques and drugs without detailed and sensitive data related to analgesia requirements, side effects, and follow-up. Current data related to benefits and complications in neonates and infants are summarized, but variability in current neuraxial drug use reflects the relative lack of high-quality evidence. Recent preclinical reports of adverse effects of general anesthetics on the developing brain have increased awareness of the potential benefit of neuraxial anesthesia/analgesia to avoid or reduce general anesthetic dose requirements. However, the developing spinal cord is also vulnerable to drug-related toxicity, and although there are well-established preclinical models and criteria for assessing spinal cord toxicity in adult animals, until recently there had been no systematic evaluation during early life. Therefore, in the second half of this review, we present preclinical data evaluating age-dependent changes in the pharmacodynamic response to different spinal analgesics, and recent studies evaluating spinal toxicity in specific developmental models. Finally, we advocate use of neuraxial drugs with the widest demonstrable safety margin and suggest minimum standards for preclinical evaluation before adoption of new analgesics or preparations into routine clinical practice.

Digitized Spiral Drawing: A Possible Biomarker for Early Parkinson’s Disease

Science.gov (United States)

San Luciano, Marta; Wang, Cuiling; Ortega, Roberto A.; Yu, Qiping; Boschung, Sarah; Soto-Valencia, Jeannie; Bressman, Susan B.; Lipton, Richard B.; Pullman, Seth; Saunders-Pullman, Rachel

2016-01-01

Introduction Pre-clinical markers of Parkinson’s Disease (PD) are needed, and to be relevant in pre-clinical disease, they should be quantifiably abnormal in early disease as well. Handwriting is impaired early in PD and can be evaluated using computerized analysis of drawn spirals, capturing kinematic, dynamic, and spatial abnormalities and calculating indices that quantify motor performance and disability. Digitized spiral drawing correlates with motor scores and may be more sensitive in detecting early changes than subjective ratings. However, whether changes in spiral drawing are abnormal compared with controls and whether changes are detected in early PD are unknown. Methods 138 PD subjects (50 with early PD) and 150 controls drew spirals on a digitizing tablet, generating x, y, z (pressure) data-coordinates and time. Derived indices corresponded to overall spiral execution (severity), shape and kinematic irregularity (second order smoothness, first order zero-crossing), tightness, mean speed and variability of spiral width. Linear mixed effect adjusted models comparing these indices and cross-validation were performed. Receiver operating characteristic analysis was applied to examine discriminative validity of combined indices. Results All indices were significantly different between PD cases and controls, except for zero-crossing. A model using all indices had high discriminative validity (sensitivity = 0.86, specificity = 0.81). Discriminative validity was maintained in patients with early PD. Conclusion Spiral analysis accurately discriminates subjects with PD and early PD from controls supporting a role as a promising quantitative biomarker. Further assessment is needed to determine whether spiral changes are PD specific compared with other disorders and if present in pre-clinical PD. PMID:27732597

NCI Pediatric Preclinical Testing Consortium

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NCI has awarded grants to five research teams to participate in its Pediatric Preclinical Testing Consortium, which is intended to help to prioritize which agents to pursue in pediatric clinical trials.

Imaging tissue hypoxia: clinical and pre-clinical experience with 123IAZA

International Nuclear Information System (INIS)

Wiebe, L.I.

1997-01-01

The molecular mechanisms that underline the selective binding of iodazomycin arabinoside, IAZA, and related nitromidazoles are reviewed as a basis for interpretation of preclinical and clinical data for hypoxic binding of radioiodinated IAZA. Clinical data are presented for 123 IAZA uptake in a number of pathologies including metastatic tumours, peripheral vascular disease in diabetes, muscle stress and rheumatoid arthritis. The results of studies to determine the influence of tumour type on uptake of 123 I-IAZA in patients with a variety of deep-seated solid tumours will be presented. Correlations of hypoxia-dependent binding with 99m Tc-HMPAO perfusion images will be reviewed and early correlations of uptake to treatment response in cancer will be presented. Unusual features of 123 I-IAZA biodistribution will also be discussed together with detailed pharmacokinetic and radiation dosimetry data for '2 123 I- IAZA in normal volunteers

Assessment of the knowledge and attitudes regarding HIV/AIDS among pre-clinical medical students in Israel

Science.gov (United States)

2014-01-01

Background Today’s medical students are the future physicians of people living with HIV/AIDS (PLWHA). It is therefore essential that medical students possess the appropriate knowledge and attitudes regarding PLWHA. This study aims to evaluate knowledge and attitudes of pre-clinical Israeli medical students and to assess whether their knowledge and attitudes change throughout their pre-clinical studies. Methods A cross-sectional study was conducted among all pre-clinical medical students from the four medical schools in Israel during the academic year of 2010/2011 (a total of 1,470 students). A self-administered questionnaire was distributed. The questionnaire sought student responses pertaining to knowledge of HIV transmission and non-transmission routes, basic knowledge of HIV/AIDS treatment and attitudes towards HIV/AIDS. Results The study’s response rate was 62.24 percent. Knowledge among pre-clinical medical students was generally high and showed a statistically significant improvement as students progressed through their pre-clinical studies. However, there were some misconceptions, mostly regarding HIV transmission via breastfeeding and knowledge of HIV prevention after exposure to the virus. Students’ attitudes were found to include stigmatizing notions. Furthermore, the majority of medical students correlated HIV with shame and fear. In addition, students’ attitudes toward HIV testing and providing confidential medical information were contradictory to health laws, protocols and guidelines. Overall, no positive changes in students’ attitudes were observed during the pre-clinical years of medical school. Conclusion The knowledge of pre-clinical medical students in Israel is generally high, although there are some knowledge inadequacies that require more emphasis in the curricula of the medical schools. Contrary to HIV-related knowledge, medical students’ attitudes are unaffected by their progression through medical school. Therefore, medical

[Classification of results of studying blood plasma with laser correlation spectroscopy based on semiotics of preclinical and clinical states].

Science.gov (United States)

Ternovoĭ, K S; Kryzhanovskiĭ, G N; Musiĭchuk, Iu I; Noskin, L A; Klopov, N V; Noskin, V A; Starodub, N F

1998-01-01

The usage of laser correlation spectroscopy for verification of preclinical and clinical states is substantiated. Developed "semiotic" classifier for solving the problems of preclinical and clinical states is presented. The substantiation of biological algorithms as well as the mathematical support and software for the proposed classifier for the data of laser correlation spectroscopy of blood plasma are presented.

Small Molecular TRAIL Inducer ONC201 Induces Death in Lung Cancer Cells: A Preclinical Study

OpenAIRE

Feng, Yuan; Zhou, Jihong; Li, Zhanhua; Jiang, Ying; Zhou, Ying

2016-01-01

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) selectively targets cancer cells. The present preclinical study investigated the anti-cancer efficiency of ONC201, a first-in-class small molecule TRAIL inducer, in lung cancer cells. We showed that ONC201 was cytotoxic and anti-proliferative in both established (A549 and H460 lines) and primary human lung cancer cells. It was yet non-cytotoxic to normal lung epithelial cells. Further, ONC201 induced exogenous apoptosis act...

The role of radiolabelled compounds in preclinical drug development

International Nuclear Information System (INIS)

Hawkins, D.R.

1988-01-01

The role of radiolabelled compounds in the development of new drugs is discussed, with particular reference to their use in toxicological, metabolic and pharmacokinetic studies for the pre-clinical safety evaluation of new drugs. (U.K.)

Left ventricular remodeling in preclinical experimental mitral regurgitation of dogs.

Science.gov (United States)

Dillon, A Ray; Dell'Italia, Louis J; Tillson, Michael; Killingsworth, Cheryl; Denney, Thomas; Hathcock, John; Botzman, Logan

2012-03-01

Dogs with experimental mitral regurgitation (MR) provide insights into the left ventricular remodeling in preclinical MR. The early preclinical left ventricular (LV) changes after mitral regurgitation represent progressive dysfunctional remodeling, in that no compensatory response returns the functional stroke volume (SV) to normal even as total SV increases. The gradual disease progression leads to mitral annulus stretch and enlargement of the regurgitant orifice, further increasing the regurgitant volume. Remodeling with loss of collagen weave and extracellular matrix (ECM) is accompanied by stretching and hypertrophy of the cross-sectional area and length of the cardiomyocyte. Isolated ventricular cardiomyocytes demonstrate dysfunction based on decreased cell shortening and reduced intracellular calcium transients before chamber enlargement or decreases in contractility in the whole heart can be clinically appreciated. The genetic response to increased end-diastolic pressure is down-regulation of genes associated with support of the collagen and ECM and up-regulation of genes associated with matrix remodeling. Experiments have not demonstrated any beneficial effects on remodeling from treatments that decrease afterload via blocking the renin-angiotensin system (RAS). Beta-1 receptor blockade and chymase inhibition have altered the progression of the LV remodeling and have supported cardiomyocyte function. The geometry of the LV during the remodeling provides insight into the importance of regional differences in responses to wall stress. Copyright © 2012 Elsevier B.V. All rights reserved.

In vivo 3-dimensional photoacoustic imaging of the renal vasculature in preclinical rodent models

OpenAIRE

Ogunlade, O.; Connell, J. J.; Huang, J. L.; Zhang, E.; Lythgoe, M. F.; Long, D. A.; Beard, P.

2017-01-01

Non-invasive imaging of the kidney vasculature in preclinical murine models is important for studying renal development, diseases and evaluating new therapies, but is challenging to achieve using existing imaging modalities. Photoacoustic imaging is a promising new technique that is particularly well suited to visualising the vasculature and could provide an alternative to existing preclinical imaging methods for studying renal vascular anatomy and function. To investigate this, an all-optica...

Mexican medicinal plants with anxiolytic or antidepressant activity: Focus on preclinical research.

Science.gov (United States)

López-Rubalcava, Carolina; Estrada-Camarena, Erika

2016-06-20

Anxiety and depression are considered the most prevalent psychiatric disorders worldwide. In Mexico, the use of medicinal plants to alleviate the symptoms associated with these psychiatric disorders is increasing. However, there is little scientific evidence that validates the efficacy of these plants. This evidence needs to be critically revised, and further studied to provided scientific support for their use. To identify the plants that are used in Mexico for the treatment of disorders related to anxiety and depression, and to review the current preclinical and when available, clinical information of these plants. We searched in scientific databases (Pubmed, Web of Science, Scopus and other web sources such as "Biblioteca digital de la medicina tradicional Mexicana" ) for Mexican plants used for the treatment of anxiety and depression that have been analyzed in preclinical studies. Additional information was obtained from published books. For this review, we also consider those plants used in Mexican traditional medicine for the treatment of "nervios," "susto" or "espanto;" common terms that describe symptoms related to anxiety and depression disorders. The bibliographic search identified 49 plants used in Mexican traditional medicine for the treatment of disorders related to anxiety and depression. From all these plants, 59% were analyzed in preclinical research, and only 8% were tested in clinical studies; only a few of these studies tried to elucidate their mechanism of action. In general, it is proposed that the plant extracts interact with the GABAergic system. However, only part of these studies attempted to analyze other neurotransmitter systems. Finally, in some cases, drug-herbal interactions were reported. There is a large number of Mexican medicinal plants used as a treatment for anxiety and depression disorders. Although some of these plants have been studied in preclinical research, in most cases these studies are preliminary, and the understanding

The predictive validity of the BioMedical Admissions Test for pre-clinical examination performance.

Science.gov (United States)

Emery, Joanne L; Bell, John F

2009-06-01

Some medical courses in the UK have many more applicants than places and almost all applicants have the highest possible previous and predicted examination grades. The BioMedical Admissions Test (BMAT) was designed to assist in the student selection process specifically for a number of 'traditional' medical courses with clear pre-clinical and clinical phases and a strong focus on science teaching in the early years. It is intended to supplement the information provided by examination results, interviews and personal statements. This paper reports on the predictive validity of the BMAT and its predecessor, the Medical and Veterinary Admissions Test. Results from the earliest 4 years of the test (2000-2003) were matched to the pre-clinical examination results of those accepted onto the medical course at the University of Cambridge. Correlation and logistic regression analyses were performed for each cohort. Section 2 of the test ('Scientific Knowledge') correlated more strongly with examination marks than did Section 1 ('Aptitude and Skills'). It also had a stronger relationship with the probability of achieving the highest examination class. The BMAT and its predecessor demonstrate predictive validity for the pre-clinical years of the medical course at the University of Cambridge. The test identifies important differences in skills and knowledge between candidates, not shown by their previous attainment, which predict their examination performance. It is thus a valid source of additional admissions information for medical courses with a strong scientific emphasis when previous attainment is very high.

Preclinical evaluation of strontium-containing bioactive bone cement

International Nuclear Information System (INIS)

Li, Zhaoyang; Yuan, Ning; Lam, Raymond Wing Moon; Cui, Zhenduo; Yang, Xianjin; Lu, William Weijia

2013-01-01

Strontium (Sr) has become more attractive for orthopaedic applications as they can simultaneously stimulate bone formation and prevent bone loss. A Sr-containing bioactive bone cement (Sr-BC) has been designed to fix osteoporotic bone fracture. Sr is a trace element, so the safety of containing Sr is concerned when Sr-BC is implanted in human body. The preclinical assessment of biocompatibility of Sr-BC was conducted according to ISO 10993 standards. MTT assay showed that this bioactive bone cement was non-toxic to mouse fibroblasts, and it met the basic requirement for the orthopaedic implant. The three independent genetic toxicity studies including Ames, chromosome aberration and bone marrow micronucleus assays demonstrated absence of genotoxic components in Sr-BC, which reassured the safety concerns of this novel bone cement. The muscle implantation results in present study were also encouraging. The acute inflammation around the cement was observed at 1 week post-implantation; however, no significant difference was observed between control and Sr-BC groups. These responses may be attributed to the presence of the foreign body, but the tissue healed after 12 weeks implantation. In summary, the above preclinical results provide additional assurance for the safety of this implant. Sr-BC can be used as a potential alternative to the traditional bone cement. - Highlights: • Strontium-containing bioactive bone cement (Sr-BC) was designed. • The biocompatibility of Sr-BC was evaluated according ISO 10993 standards. • Preclinical results provide additional assurance for the safety of Sr-BC

Preclinical evaluation of strontium-containing bioactive bone cement

Energy Technology Data Exchange (ETDEWEB)

Li, Zhaoyang, E-mail: lizy@hku.hk [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Composite and Functional Materials, Tianjin 300072 (China); Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong (China); Yuan, Ning [Department of Laboratory Medicine, Tianjin Chest Hospital, Tianjin 300051 (China); Lam, Raymond Wing Moon [Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong (China); Cui, Zhenduo; Yang, Xianjin [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Composite and Functional Materials, Tianjin 300072 (China); Lu, William Weijia, E-mail: wwlu@hku.hk [Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong (China)

2013-12-01

Strontium (Sr) has become more attractive for orthopaedic applications as they can simultaneously stimulate bone formation and prevent bone loss. A Sr-containing bioactive bone cement (Sr-BC) has been designed to fix osteoporotic bone fracture. Sr is a trace element, so the safety of containing Sr is concerned when Sr-BC is implanted in human body. The preclinical assessment of biocompatibility of Sr-BC was conducted according to ISO 10993 standards. MTT assay showed that this bioactive bone cement was non-toxic to mouse fibroblasts, and it met the basic requirement for the orthopaedic implant. The three independent genetic toxicity studies including Ames, chromosome aberration and bone marrow micronucleus assays demonstrated absence of genotoxic components in Sr-BC, which reassured the safety concerns of this novel bone cement. The muscle implantation results in present study were also encouraging. The acute inflammation around the cement was observed at 1 week post-implantation; however, no significant difference was observed between control and Sr-BC groups. These responses may be attributed to the presence of the foreign body, but the tissue healed after 12 weeks implantation. In summary, the above preclinical results provide additional assurance for the safety of this implant. Sr-BC can be used as a potential alternative to the traditional bone cement. - Highlights: • Strontium-containing bioactive bone cement (Sr-BC) was designed. • The biocompatibility of Sr-BC was evaluated according ISO 10993 standards. • Preclinical results provide additional assurance for the safety of Sr-BC.

Is medical students' moral orientation changeable after preclinical medical education?

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Lin, Chaou-Shune; Tsou, Kuo-Inn; Cho, Shu-Ling; Hsieh, Ming-Shium; Wu, Hsi-Chin; Lin, Chyi-Her

2012-03-01

Moral orientation can affect ethical decision-making. Very few studies have focused on whether medical education can change the moral orientation of the students. The purpose of the present study was to document the types of moral orientation exhibited by medical students, and to study if their moral orientation was changed after preclinical education. From 2007 to 2009, the Mojac scale was used to measure the moral orientation of Taiwan medical students. The students included 271 first-year and 109 third-year students. They were rated as a communitarian, dual, or libertarian group and followed for 2 years to monitor the changes in their Mojac scores. In both first and third-year students, the dual group after 2 years of preclinical medical education did not show any significant change. In the libertarian group, first and third-year students showed a statistically significant increase from a score of 99.4 and 101.3 to 103.0 and 105.7, respectively. In the communitarian group, first and third-year students showed a significant decline from 122.8 and 126.1 to 116.0 and 121.5, respectively. During the preclinical medical education years, students with communitarian orientation and libertarian orientation had changed in their moral orientation to become closer to dual orientation. These findings provide valuable hints to medical educators regarding bioethics education and the selection criteria of medical students for admission.

Combined preclinical magnetic particle imaging and magnetic resonance imaging. Initial results in mice

International Nuclear Information System (INIS)

Kaul, M.G.; Mummert, T.; Jung, C.; Raabe, N.; Ittrich, H.; Adam, G.; Heinen, U.; Reitmeier, A.

2015-01-01

Magnetic particle imaging (MPI) is a new radiologic imaging modality. For the first time, a commercial preclinical scanner is installed. The goal of this study was to establish a workflow between MPI and magnetic resonance imaging (MRI) scanners for a complete in vivo examination of a mouse and to generate the first co-registered in vivo MR-MP images. The in vivo examination of five mice were performed on a preclinical MPI scanner and a 7 Tesla preclinical MRI system. MRI measurements were used for anatomical referencing and validation of the injection of superparamagnetic iron oxide (SPIO) particles during a dynamic MPI scan. We extracted MPI data of the injection phase and co-registered it with MRI data. A workflow process for a combined in vivo MRI and MPI examination was established. A successful injection of ferucarbotran was proven in MPI and MRI. MR-MPI co-registration allocated the SPIOs in the inferior vena cava and the heart during and shortly after the injection. The acquisition of preclinical MPI and MRI data is feasible and allows the combined analysis of MR-MPI information.

Combined preclinical magnetic particle imaging and magnetic resonance imaging. Initial results in mice

Energy Technology Data Exchange (ETDEWEB)

Kaul, M.G.; Mummert, T.; Jung, C.; Raabe, N.; Ittrich, H.; Adam, G. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Diagnostic and Interventional Radiology; Weber, O. [Philips Medical Systems DMC GmbH, Hamburg (Germany); Heinen, U. [Bruker BioSpin MRI GmbH, Ettlingen (Germany); Reitmeier, A. [Medical Center Hamburg-Eppendorf, Hamburg (Germany). Animal Facility; Knopp, T. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Diagnostic and Interventional Radiology; Hamburg University of Technology, Hamburg (Germany)

2015-05-15

Magnetic particle imaging (MPI) is a new radiologic imaging modality. For the first time, a commercial preclinical scanner is installed. The goal of this study was to establish a workflow between MPI and magnetic resonance imaging (MRI) scanners for a complete in vivo examination of a mouse and to generate the first co-registered in vivo MR-MP images. The in vivo examination of five mice were performed on a preclinical MPI scanner and a 7 Tesla preclinical MRI system. MRI measurements were used for anatomical referencing and validation of the injection of superparamagnetic iron oxide (SPIO) particles during a dynamic MPI scan. We extracted MPI data of the injection phase and co-registered it with MRI data. A workflow process for a combined in vivo MRI and MPI examination was established. A successful injection of ferucarbotran was proven in MPI and MRI. MR-MPI co-registration allocated the SPIOs in the inferior vena cava and the heart during and shortly after the injection. The acquisition of preclinical MPI and MRI data is feasible and allows the combined analysis of MR-MPI information.

Nephron segment specific microRNA biomarkers of pre-clinical drug-induced renal toxicity: Opportunities and challenges

Energy Technology Data Exchange (ETDEWEB)

Nassirpour, Rounak, E-mail: Rounak.nassirpour@pfizer.com [Drug Safety, Pfizer Worldwide Research and Development, 1 Burtt Rd, Andover, MA 01810 (United States); Ramaiah, Shashi K. [Drug Safety, Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, MA 02139 (United States); Whiteley, Laurence O. [Drug Safety, Pfizer Worldwide Research and Development, 1 Burtt Rd, Andover, MA 01810 (United States)

2016-12-01

Drug-induced nephrotoxicity is a common drug development complication for pharmaceutical companies. Sensitive, specific, translatable and non-invasive biomarkers of renal toxicity are urgently needed to diagnose nephron segment specific injury. The currently available gold standard biomarkers for nephrotoxicity are not kidney-specific, lack sensitivity for early detection, and are not suitable for renal damage localization (glomerular vs tubulointerstitial injury). MicroRNAs (miRNAs) are increasingly gaining momentum as promising biomarkers of various organ toxicities, including drug induced renal injury. This is mostly due to their stability in easily accessible biofluids, ease of developing nucleic acids detection compared to protein detection assays, as well as their interspecies translatability. Increasing concordance of miRNA findings by standardizing methodology most suitable for their detection and quantitation, as well as characterization of their expression pattern in a cell type specific manner, will accelerate progress toward validation of these miRNAs as biomarkers in pre-clinical, and clinical settings. This review aims to highlight the current pre-clinical findings surrounding miRNAs as biomarkers in two important segments of the nephron, the glomerulus and tubules. - Highlights: • miRNAs are promising biomarkers of drug-induced kidney injury. • Summarized pre-clinical miRNA biomarkers of drug-induced nephrotoxicity. • Described the strengths and challenges associated with miRNAs as biomarkers.

Anatomy meets dentistry! Linking anatomy and clinical practice in the preclinical dental curriculum

Directory of Open Access Journals (Sweden)

Nicole Rafai

2016-11-01

Full Text Available Abstract Background Establishing a strong link early on between preclinical coursework and the clinical context is necessary for students to be able to recognize the practical relevance of the curriculum during their preclinical anatomical courses and to transfer knowledge more easily. Our objective was to enhance the clinical relevance of a preclinical anatomy course for second-year medical students of dentistry by implementing an interdisciplinary skills training course on “Palpation of the Head and Neck Muscles” and to measure the learning outcomes. Methods For the curricular development of the expanded course module, Kern’s 6-step approach was applied including subjective evaluation. We used a peer-teaching format supported by an e-learning application. A randomized control study measured effects of the two components (skills training, e-module on learning outcomes. Four learning methods were compared: (1 lecture, (2 lecture + e-module, (3 lecture + skills training, (4 lecture + skills training + e-module. An objective structured clinical examination (OSCE was used to measure and compare learning outcomes. Results The two-way variance analysis demonstrated that participation in the skills training had a statistically significant effect on the OSCE results (p = 0.0007. Students who participated in the skills training did better (φ 107.4 ± 14.4 points than students who only attended the lecture (φ 88.8 ± 26.2 points. Students who used the e-module but did not attend the skills training earned a slightly but not significantly higher average number of points (φ 91.8 ± 31.3 points than those who only attended the lecture. The learning outcomes of the skills training were again significantly increased when the training was combined with the e-module (φ 121.8 ± 21.8 points, thus making it the ideal method for achieving the learning objectives defined in this study. Conclusions The “Palpation of

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

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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

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

Science.gov (United States)

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

Learning style preferences: A study of Pre-clinical Medical Students in Barbados

Directory of Open Access Journals (Sweden)

NKEMCHO OJEH

2017-10-01

Full Text Available 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 preclinical 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

Preclinical acute toxicity, biodistribution, pharmacokinetics, radiation dosimetry and microPET imaging studies of ["1"8F]fluorocholine in mice

International Nuclear Information System (INIS)

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

2016-01-01

["1"8F]Fluorocholine (["1"8F]FCH) has been proven to be effective in prostate cancer. Since ["1"8F]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 ["1"8F]FCH. The results could support its use in nuclear medicine as an important piece of work for regulatory in Brazil. - Highlights: • Data demonstrated the high quality, safety and effectiveness of ["1"8F]FCH. • ["1"8F]FCH preclinical profile is in accordance with previously published. • Toxicity, distribution, kinetics and radiation dosimetry were well characterized. • The results are important for regulatory issues in Brazil and other countries.

Identification of new epilepsy treatments: issues in preclinical methodology.

Science.gov (United States)

Galanopoulou, Aristea S; Buckmaster, Paul S; Staley, Kevin J; Moshé, Solomon L; Perucca, Emilio; Engel, Jerome; Löscher, Wolfgang; Noebels, Jeffrey L; Pitkänen, Asla; Stables, James; White, H Steve; O'Brien, Terence J; Simonato, Michele

2012-03-01

Preclinical research has facilitated the discovery of valuable drugs for the symptomatic treatment of epilepsy. Yet, despite these therapies, seizures are not adequately controlled in a third of all affected individuals, and comorbidities still impose a major burden on quality of life. The introduction of multiple new therapies into clinical use over the past two decades has done little to change this. There is an urgent demand to address the unmet clinical needs for: (1) new symptomatic antiseizure treatments for drug-resistant seizures with improved efficacy/tolerability profiles, (2) disease-modifying treatments that prevent or ameliorate the process of epileptogenesis, and (3) treatments for the common comorbidities that contribute to disability in people with epilepsy. New therapies also need to address the special needs of certain subpopulations, that is, age- or gender-specific treatments. Preclinical development in these treatment areas is complex due to heterogeneity in presentation and etiology, and may need to be formulated with a specific seizure, epilepsy syndrome, or comorbidity in mind. The aim of this report is to provide a framework that will help define future guidelines that improve and standardize the design, reporting, and validation of data across preclinical antiepilepsy therapy development studies targeting drug-resistant seizures, epileptogenesis, and comorbidities. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

The interplay between academic performance and quality of life among preclinical students.

Science.gov (United States)

Shareef, Mohammad Abrar; AlAmodi, Abdulhadi A; Al-Khateeb, Abdulrahman A; Abudan, Zainab; Alkhani, Mohammed A; Zebian, Sanderlla I; Qannita, Ahmed S; Tabrizi, Mariam J

2015-10-31

The high academic performance of medical students greatly influences their professional competence in long term career. Meanwhile, medical students greatly demand procuring a good quality of life that can help them sustain their medical career. This study examines validity and reliability of the tool among preclinical students and testifies the influence of their scholastic performance along with gender and academic year on their quality of life. A cross sectional study was conducted by distributing World Health Organization Quality of Life, WHOQOL-BREF, survey among medical students of year one to three at Alfaisal University. For validity, item discriminate validity(IDV) and confirmatory factor analysis were measured and for reliability, Cronbach's α test and internal item consistency(IIC) were examined. The association of GPA, gender and academic year with all major domains was drawn using Pearson's correlation, independent samples t-test and one-way ANOVA, respectively. A total of 335 preclinical students have responded to this questionnaire. The construct has demonstrated an adequate validity and good reliability. The high academic performance of students positively correlated with physical (r = 0.23, p student scored higher than female peers in physical and psychological health. This study has identified a direct relationship between the academic performance of preclinical students and their quality of life. The WHOQOL-BREF is a valid and reliable tool among preclinical students and the positive direction of high academic performance with greater QOL suggests that academic achievers procure higher satisfaction and poor achievers need a special attention for the improvement of their quality of life.

Preclinical Cancer Chemoprevention Studies Using Animal Model of Inflammation-Associated Colorectal Carcinogenesis

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Tanaka, Takuji [Cytopatholgy Division, Tohkai Cytopathology Institute, Cancer Research and Prevention (TCI-CaRP), 5-1-2 Minami-uzura, Gifu 500-8285 (Japan); Department of Tumor Pathology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan)

2012-07-16

Inflammation is involved in all stages of carcinogenesis. Inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease is a longstanding inflammatory disease of intestine with increased risk for colorectal cancer (CRC). Several molecular events involved in chronic inflammatory process are reported to contribute to multi-step carcinogenesis of CRC in the inflamed colon. They include over-production of free radicals, reactive oxygen and nitrogen species, up-regulation of inflammatory enzymes in arachidonic acid biosynthesis pathway, up-regulation of certain cytokines, and intestinal immune system dysfunction. In this article, firstly I briefly introduce our experimental animal models where colorectal neoplasms rapidly develop in the inflamed colorectum. Secondary, data on preclinical cancer chemoprevention studies of inflammation-associated colon carcinogenesis by morin, bezafibrate, and valproic acid, using this novel inflammation-related colorectal carcinogenesis model is described.

Low Cognitive Awareness, but Not Complaint, is a Good Marker of Preclinical Alzheimer's Disease.

Science.gov (United States)

Cacciamani, Federica; Tandetnik, Caroline; Gagliardi, Geoffroy; Bertin, Hugo; Habert, Marie-Odile; Hampel, Harald; Boukadida, Laurie; Révillon, Marie; Epelbaum, Stéphane; Dubois, Bruno

2017-01-01

Subjective cognitive decline (SCD) may result from many conditions, including Alzheimer's disease (AD). In this study, we searched for a specific pattern of SCD in asymptomatic individuals at risk for AD. Cognitively normal older adults (N = 318) reporting SCD and their informants were enrolled in the INSIGHT-PreAD cohort. We examined the relationship between six SCD measures and both cognitive scores and AD neuroimaging markers (amyloid burden, hippocampal atrophy and brain hypometabolism). An awareness of cognitive decline index (ACDI) has been introduced based on the subject-informant discrepancy in a questionnaire of SCD and participants with low versus high awareness were compared. Scores in the INSIGHT-PreAD SCD questionnaires did not correlate with AD neuroimaging markers. As well, no correlation has been found between SCD measures and cognitive scores. Comparing subjects with a low (n = 19) and high (n = 86) level of awareness, no significant difference in terms of demography, neuropsychiatric symptoms, autonomy, quality of life, cognition, and hippocampal volume was found. However, the "low awareness" group showed greater amyloid burden and lower cortical metabolism, compared to the "high awareness" group. This study provided additional evidence that reporting SCD by itself is not a specific symptom of preclinical AD. Conversely, a low cognitive awareness (namely, when subjects report fewer difficulties than their relatives do) may represent a very early form of anosognosia and serve as a specific indicator of preclinical AD. This finding is of key importance as an enrichment factor to consider in both clinical practice and research trials.

A controlled, randomized, delayed-start study of rasagiline in early Parkinson disease.

Science.gov (United States)

2004-04-01

Treatment with rasagiline mesylate, an irreversible monoamine oxidase type B inhibitor, improves symptoms of early Parkinson disease (PD). Preclinical studies suggest that this compound may also modify the progression of PD. To compare the effects of early and later initiation of rasagiline on progression of disability in patients with PD. Double-blind, parallel-group, randomized, delayed-start clinical trial. Four hundred four subjects with early PD, not requiring dopaminergic therapy, enrolled at 32 sites in the United States and Canada. Subjects were randomized to receive rasagiline, 1 or 2 mg/d, for 1 year or placebo for 6 months followed by rasagiline, 2 mg/d, for 6 months. Change in total Unified Parkinson's Disease Rating Scale score from baseline to 12 months. Three hundred seventy-one subjects were included in the 1-year efficacy analysis. Subjects treated with rasagiline, 2 mg/d, for 1 year had a 2.29-unit smaller increase in mean adjusted total Unified Parkinson's Disease Rating Scale score compared with subjects treated with placebo for 6 months followed by rasagiline, 2 mg/d, for 6 months (P =.01). The mean adjusted difference between the placebo/rasagiline, 2 mg/d, group and those receiving rasagiline, 1 mg/d, for 1 year was -1.82 unit on the Unified Parkinson's Disease Rating Scale score (P =.05). Subjects treated with rasagiline, 2 and 1 mg/d, for 12 months showed less functional decline than subjects whose treatment was delayed for 6 months.

Preclinical animal research on therapy dosimetry with dual isotopes

International Nuclear Information System (INIS)

Konijnenberg, Mark W.; Jong, Marion de

2011-01-01

Preclinical research into radionuclide therapies based on radiation dosimetry will enable the use of any LET-equivalent radionuclide. Radiation dose and dose rate have significant influence on dose effects in the tumour depending on its radiation sensitivity, possibilities for repair of sublethal damage, and repopulation during or after the therapy. Models for radiation response of preclinical tumour models after peptide receptor radionuclide therapy based on the linear quadratic model are presented. The accuracy of the radiation dose is very important for observation of dose-effects. Uncertainties in the radiation dose estimation arise from incomplete assay of the kinetics, low accuracy in volume measurements and absorbed dose S-values for stylized models instead of the actual animal geometry. Normal dose uncertainties in the order of 20% might easily make the difference between seeing a dose-effect or missing it altogether. This is true for the theoretical case of a homogeneous tumour type behaving in vivo in the same way as its cells do in vitro. Heterogeneity of tumours induces variations in clonogenic cell density, radiation sensitivity, repopulation capacity and repair kinetics. The influence of these aspects are analysed within the linear quadratic model for tumour response to radionuclide therapy. Preclinical tumour models tend to be less heterogenic than the clinical conditions they should represent. The results of various preclinical radionuclide therapy experiments for peptide receptor radionuclide therapy are compared to the outcome of theoretical models and the influence of increased heterogeneity is analysed when the results of preclinical research is transferred to the clinic. When the radiation dose and radiobiology of the tumour response is known well enough it may be possible to leave the current phenomenological approach in preclinical radionuclide therapy and start basing these experiments on radiation dose. Then the use of a gamma ray

Preclinical animal research on therapy dosimetry with dual isotopes

Energy Technology Data Exchange (ETDEWEB)

Konijnenberg, Mark W.; Jong, Marion de [Nuclear Medicine Department, Erasmus MC, Rotterdam (Netherlands)

2011-06-15

Preclinical research into radionuclide therapies based on radiation dosimetry will enable the use of any LET-equivalent radionuclide. Radiation dose and dose rate have significant influence on dose effects in the tumour depending on its radiation sensitivity, possibilities for repair of sublethal damage, and repopulation during or after the therapy. Models for radiation response of preclinical tumour models after peptide receptor radionuclide therapy based on the linear quadratic model are presented. The accuracy of the radiation dose is very important for observation of dose-effects. Uncertainties in the radiation dose estimation arise from incomplete assay of the kinetics, low accuracy in volume measurements and absorbed dose S-values for stylized models instead of the actual animal geometry. Normal dose uncertainties in the order of 20% might easily make the difference between seeing a dose-effect or missing it altogether. This is true for the theoretical case of a homogeneous tumour type behaving in vivo in the same way as its cells do in vitro. Heterogeneity of tumours induces variations in clonogenic cell density, radiation sensitivity, repopulation capacity and repair kinetics. The influence of these aspects are analysed within the linear quadratic model for tumour response to radionuclide therapy. Preclinical tumour models tend to be less heterogenic than the clinical conditions they should represent. The results of various preclinical radionuclide therapy experiments for peptide receptor radionuclide therapy are compared to the outcome of theoretical models and the influence of increased heterogeneity is analysed when the results of preclinical research is transferred to the clinic. When the radiation dose and radiobiology of the tumour response is known well enough it may be possible to leave the current phenomenological approach in preclinical radionuclide therapy and start basing these experiments on radiation dose. Then the use of a gamma ray

Preclinical Studies of Chemotherapy Using Histone Deacetylase Inhibitors in Endometrial Cancer

Directory of Open Access Journals (Sweden)

Noriyuki Takai

2010-01-01

Full Text Available Because epigenetic alterations are believed to be involved in the repression of tumor suppressor genes and promotion of tumorigenesis in endometrial cancers, novel compounds endowed with a histone deacetylase (HDAC inhibitory activity are an attractive therapeutic approach. In this review, we discuss the biologic and therapeutic effects of HDAC inhibitors (HDACIs in treating endometrial cancer. HDACIs were able to mediate inhibition of cell growth, cell cycle arrest, apoptosis, and the expression of genes related to the malignant phenotype in a variety of endometrial cancer cell lines. Furthermore, HDACIs were able to induce the accumulation of acetylated histones in the chromatin of the p21WAF1 gene in human endometrial carcinoma cells. In xenograft models, some HDACIs have demonstrated antitumor activity with only few side effects. In this review, we discuss the biologic and therapeutic effects of HDACIs in treating endometrial cancer, with a special focus on preclinical studies.

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

Directory of Open Access Journals (Sweden)

Kuo-Chen Wei

Full Text Available 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.

Early-life adversity programs emotional functions and the neuroendocrine stress system: the contribution of nutrition, metabolic hormones and epigenetic mechanisms

NARCIS (Netherlands)

Yam, K.Y.; Naninck, E.F.G.; Schmidt, M.V.; Lucassen, P.J.; Korosi, A.

2015-01-01

Clinical and pre-clinical studies have shown that early-life adversities, such as abuse or neglect, can increase the vulnerability to develop psychopathologies and cognitive decline later in life. Remarkably, the lasting consequences of stress during this sensitive period on the

Elective courses for medical students during the preclinical curriculum: a systematic review and evaluation

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Ankit Agarwal

2015-05-01

Full Text Available Objective: Preclinical medical student electives are prevalent at medical schools across the United States, but the range of electives available and their impact on medical student education are not well described in the literature. The objective of this article is to review the literature relating to preclinical medical student electives and their impact on medical student educational outcomes. Methods: We reviewed studies that met the following criteria: English-language articles describing preclinical US-based medical electives. We used PubMed journal databases and limited our search for the time period 1999–2014. We excluded electives based in other countries or electives designed for third or fourth year students. Data abstracted included the topic of the elective, qualitative descriptions of the electives, and any associated surveys or exam data associated with the electives. Data were synthesized using descriptive tables sorting electives by broad topic. Reported outcomes and statistical methods were analyzed to assess study quality. Results: We found a wide range of subjects taught in the form of preclinical medical school electives. We identified electives in clinical skills, the humanities, student lifestyle, specialty-specific electives, and an assortment of other miscellaneous electives. Surveys and exams administered to students showed that the electives were universally well received by students. Of the 37 electives identified, 15 electives used quantitative objective assessments, such as knowledge exams, while the remaining tended to use student self-reported results. Conclusions: Preclinical medical student electives are prevalent at medical schools across the United States and have a significant impact on medical student education.

Imaging tissue hypoxia: clinical and pre-clinical experience with {sup 123}IAZA

Energy Technology Data Exchange (ETDEWEB)

Wiebe, L.I. [University of Alberta, Edmonton (Canada). Noujaim Institute for Pharmaceutical Oncology Research, Faculty of Pharmacy and Pharmaceutical Sciences

1997-10-01

The molecular mechanisms that underline the selective binding of iodazomycin arabinoside, IAZA, and related nitromidazoles are reviewed as a basis for interpretation of preclinical and clinical data for hypoxic binding of radioiodinated IAZA. Clinical data are presented for {sup 123}IAZA uptake in a number of pathologies including metastatic tumours, peripheral vascular disease in diabetes, muscle stress and rheumatoid arthritis. The results of studies to determine the influence of tumour type on uptake of {sup 123} I-IAZA in patients with a variety of deep-seated solid tumours will be presented. Correlations of hypoxia-dependent binding with {sup 99m}Tc-HMPAO perfusion images will be reviewed and early correlations of uptake to treatment response in cancer will be presented. Unusual features of {sup 123}I-IAZA biodistribution will also be discussed together with detailed pharmacokinetic and radiation dosimetry data for `2{sup 123}I- IAZA in normal volunteers 27 refs., 1 fig.

Stem cell therapy for the treatment of early stage avascular necrosis of the femoral head: a systematic review

Science.gov (United States)

2014-01-01

Background Avascular necrosis (AVN) of the femoral head (FH) is believed to be caused by a multitude of etiologic factors and is associated with significant morbidity in younger populations. Eventually, the disease progresses and results in FH collapse. Thus, a focus on early disease management aimed at joint preservation by preventing or delaying progression is key. The use of stem cells (SC) for the treatment of AVN of the FH has been proposed. We undertook a systematic review of the medical literature examining the use of SC for the treatment of early stage (precollapse) AVN of the FH, in both pre-clinical and clinical studies. Methods Data collected included: Pre-clinical studies – model of AVN, variety and dosage of SC, histologic and imaging analyses. Clinical studies – study design, classification and etiology of AVN, SC dosage and treatment protocol, incidence of disease progression, patient reported outcomes, volume of necrotic lesion and hip survivorship. Results In pre-clinical studies, the use of SC uniformly demonstrated improvements in osteogenesis and angiogenesis, yet source of implanted SC was variable. In clinical studies, groups treated with SC showed significant improvements in patient reported outcomes; however hip survivorship was not affected. Discrepancies regarding dose of SC, AVN etiology and disease severity were present. Conclusions Routine use of this treatment method will first require further research into dose and quality optimization as well as confirmed improvements in hip survivorship. PMID:24886648

Preclinical deposition of pathological prion protein in muscle of experimentally infected primates.

Directory of Open Access Journals (Sweden)

Susanne Krasemann

Full Text Available Prion diseases are transmissible fatal neurodegenerative disorders affecting humans and animals. A central step in disease progression is the accumulation of a misfolded form (PrP(Sc of the host encoded prion protein (PrP(C in neuronal and non-neuronal tissues. The involvement of peripheral tissues in preclinical states increases the risk of accidental transmission. On the other hand, detection of PrP(Sc in non-neuronal easy-accessible compartments such as muscle may offer a novel diagnostic tool. Primate models have proven invaluable to investigate prion diseases. We have studied the deposition of PrP(Sc in muscle and central nervous system of rhesus monkeys challenged with sporadic Creutzfeldt-Jakob disease (sCJD, variant CJD (vCJD and bovine spongiform encephalopathy (BSE in preclinical and clinical stage using biochemical and morphological methods. Here, we show the preclinical presence of PrP(Sc in muscle and central nervous system of rhesus monkeys experimentally infected with vCJD.

EGFR-targeted anti-cancer drugs in radiotherapy: Preclinical evaluation of mechanisms

International Nuclear Information System (INIS)

Baumann, Michael; Krause, Mechthild; Dikomey, Ekkehard; Dittmann, Klaus; Doerr, Wolfgang; Kasten-Pisula, Ulla; Rodemann, H. Peter

2007-01-01

Preclinical and clinical results indicate that the EGFR can mediate radioresistance in different solid human tumours. Combination of radiotherapy and EGFR inhibitors can improve local tumour control compared to irradiation alone and has been introduced into clinical radiotherapy practice. So far several mechanisms have been identified in preclinical studies to contribute to improved local tumour control after radiation combined with EGFR inhibitors. These include direct kill of cancer stem cells by EGFR inhibitors, cellular radiosensitization through modified signal transduction, inhibition of repair of DNA damage, reduced repopulation and improved reoxygenation during fractionated radiotherapy. Effects and mechanisms may differ for different classes of EGFR inhibitors, for different tumours and for normal tissues. The mechanisms underlying this heterogeneity are currently poorly understood, and predictive assays are not available yet. Importantly, mechanisms and predictors for the combined effects of radiation with EGFR inhibitors appear to be considerably different to those for application of EGFR inhibitors alone or in combination with chemotherapy. Therefore to further evaluate the efficacy and mechanisms of EGFR-inhibition in combined treatments, radiotherapy-specific preclinical research strategies, which include in vivo experiments using local tumour control as an endpoint, as well as animal studies on normal tissue toxicity are needed

Enhancing translation: guidelines for standard pre-clinical experiments in mdx mice.

Science.gov (United States)

Willmann, Raffaella; De Luca, Annamaria; Benatar, Michael; Grounds, Miranda; Dubach, Judith; Raymackers, Jean-Marc; Nagaraju, Kanneboyina

2012-01-01

Duchenne Muscular Dystrophy is an X-linked disorder that affects boys and leads to muscle wasting and death due to cardiac involvement and respiratory complications. The cause is the absence of dystrophin, a large structural protein indispensable for muscle cell function and viability. The mdx mouse has become the standard animal model for pre-clinical evaluation of potential therapeutic treatments. Recent years have seen a rapid increase in the number of experimental compounds being evaluated in the mdx mouse. There is, however, much variability in the design of these pre-clinical experimental studies. This has made it difficult to interpret and compare published data from different laboratories and to evaluate the potential of a treatment for application to patients. The authors therefore propose the introduction of a standard study design for the mdx mouse model. Several aspects, including animal care, sampling times and choice of tissues, as well as recommended endpoints and methodologies are addressed and, for each aspect, a standard procedure is proposed. Testing of all new molecules/drugs using a widely accepted and agreed upon standard experimental protocol would greatly improve the power of pre-clinical experimentations and help identifying promising therapies for the translation into clinical trials for boys with Duchenne Muscular Dystrophy. Copyright © 2011 Elsevier B.V. All rights reserved.

Neuroprotection in Parkinson's disease: A systematic review of the preclinical data

NARCIS (Netherlands)

Douna, H.; Bavelaar, B.M.; Pellikaan, H.; Olivier, B.; Pieters, T.

2012-01-01

Aim: This study aimed to systematically review the preclinical data of neuroprotective agents for Parkinson's disease (PD) to support the translation of these compounds. Methods: The study consisted of two phases. In phase I, Pubmed and Scopus were systematically searched for neuroprotective agents

Cued memory decline in biomarker-defined preclinical Alzheimer disease.

Science.gov (United States)

Papp, Kathryn V; Rentz, Dorene M; Mormino, Elizabeth C; Schultz, Aaron P; Amariglio, Rebecca E; Quiroz, Yakeel; Johnson, Keith A; Sperling, Reisa A

2017-04-11

To determine whether a decline in cued recall is observable in the preclinical stage of Alzheimer disease (AD) in clinically normal older adults with elevated β-amyloid (Aβ) burden on PET imaging. Clinically normal older adults underwent baseline neuroimaging (PET to assess Aβ +/- status and MRI) and annual neuropsychological testing. Cox proportional hazards models were used to assess the relative risk of cued memory decline (drop of 1, 2, 3, or 4 points on the total score of the Free and Cued Selective Reminding Test) in relation to neuroimaging measures, functional status, age, sex, and education. A total of 276 older adults (Clinical Dementia Rating = 0, mean Mini-Mental State Examination score = 29 ± 1.06) were followed up for a mean of 3.6 ± 1.2 years. Despite the infrequency of cued memory decline (only 19% of participants scored ≤46/48 in total recall by year 3), Aβ + participants were 3.55 times (95% confidence interval = 1.77-7.12) more likely to exhibit decline in total recall (≤46/48) compared with their Aβ - peers. Furthermore, Aβ + participants who scored ≤46/48 had smaller hippocampal volumes ( t = 3.37, p = 0.001) and evidence of early functional decline, i.e., greater risk of progression to global Clinical Dementia Rating of 0.5 (χ 2 = 14.30, p recall. Cued memory decline in healthy older adults may be particularly indicative of Aβ-related decline during the preclinical stage of AD and useful for identifying Aβ + clinically normal individuals at greatest risk of short-term clinical progression. © 2017 American Academy of Neurology.

A Flexible, Preclinical, Medical School Curriculum Increases Student Academic Productivity and the Desire to Conduct Future Research

Science.gov (United States)

Peacock, Justin G.; Grande, Joseph P.

2015-01-01

In 2006, small blocks of flexible curriculum time, termed selectives, were implemented in the Mayo Medical School preclinical curriculum. Selectives permitted students to pursue professional endeavors, such as research, service, and career exploration, in the preclinical years. The purpose of this study was to survey current and former Mayo…

Identification of new treatments for epilepsy: issues in preclinical methodology

Science.gov (United States)

Galanopoulou, Aristea S.; Buckmaster, Paul S.; Staley, Kevin J.; Moshé, Solomon L.; Perucca, Emilio; Engel, Jerome; Löscher, Wolfgang; Noebels, Jeffrey L.; Pitkänen, Asla; Stables, James; White, Steve H.; O’Brien, Terence J.; Simonato, Michele

2013-01-01

Summary Preclinical research has facilitated the discovery of valuable drugs for the symptomatic treatment of epilepsy. Yet, despite these therapies, seizures are not adequately controlled in a third of all affected individuals, and comorbidities still impose a major burden on quality of life. The introduction of multiple new therapies into clinical use over the past two decades has done little to change this. There is an urgent demand to address the unmet clinical needs for: (a) new symptomatic anti-seizure treatments for drug-resistant seizures with improved efficacy/tolerability profiles, (b) disease modifying treatments that prevent or ameliorate the epileptogenic state, and (c) treatments for the common comorbidities that contribute to disability in people with epilepsy. New therapies also need to address the special needs of certain subpopulations, i.e. age- or gender-specific treatments. Preclinical development in these treatment areas is complex due to heterogeneity in presentation and etiology, and may need to be formulated with a specific seizure, epilepsy syndrome or comorbidity in mind. The aim of this report is to provide a framework that will help define future guidelines that improve and standardize the design, reporting, and validation of data across preclinical anti-epilepsy therapy development studies targeting drug-resistant seizures, epileptogenesis and comorbidities. PMID:22292566

Chronic radiation-induced leukemogenesis: alterations of hematopoietic progenitor repair functions during preclinical phases

International Nuclear Information System (INIS)

Seed, T.M.; Kaspar, L.V.; Grdina, D.J.; Frazier, M.E.

1987-01-01

Chronic exposure to low daily doses of whole-body gamma irradiation elicits a high incidence of myeloid leukemia (ML) and related myeloproliferative diseases (MPD) in beagles. Previously, the authors identified and partially characterized a four-phase sequence of evolving MPD as a consequence of chronic radiation exposure. With a focus on preclinical alterations in granulocyte/monocyte-committed stem cells, they have identified two critical events in the process: (i) an early event, involving the coupling of acquired radioresistance of the stem cell with renewed proliferative capacity; and (ii) a late event, involving acquired autocrine functions and associated change in stem cell clonality. In terms of the early event, repair-associated parameters are currently being examined on the cellular level by both split-dose and low dose-rate-type assays with survival enhancement used as the measured end point. On the molecular level, these parameters are examined by microfluorometric alkaline elution assays with DNA damage and repair used as end points

Novel technology to prepare oral formulations for preclinical safety studies.

Science.gov (United States)

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.

Effects of the Natural β-Carboline Alkaloid Harmine, a Main Constituent of Ayahuasca, in Memory and in the Hippocampus: A Systematic Literature Review of Preclinical Studies.

Science.gov (United States)

Dos Santos, Rafael G; Hallak, Jaime E C

2017-01-01

Harmine is a natural β-carboline alkaloid found in several botanical species, such as the Banisteriopsis caapi vine used in the preparation of the hallucinogenic beverage ayahuasca and the seeds of Syrian rue (Peganum harmala). Preclinical studies suggest that harmine may have neuroprotective and cognitive-enhancing effects, and retrospective/observational investigations of the mental health of long-term ayahuasca users suggest that prolonged use of this harmine-rich hallucinogen is associated with better neuropsychological functioning. Thus, in order to better investigate these possibilities, we performed a systematic literature review of preclinical studies analyzing the effects of harmine on hippocampal neurons and in memory-related behavioral tasks in animal models. We found two studies involving hippocampal cell cultures and nine studies using animal models. Harmine administration was associated with neuroprotective effects such as reduced excitotoxicity, inflammation, and oxidative stress, and increased brain-derived neurotrophic factor (BDNF) levels. Harmine also improved memory/learning in several animal models. These effects seem be mediated by monoamine oxidase or acetylcholinesterase inhibition, upregulation of glutamate transporters, decreases in reactive oxygen species, increases in neurotrophic factors, and anti-inflammatory effects. The neuroprotective and cognitive-enhancing effects of harmine should be further investigated in both preclinical and human studies.

The potential of shark bone powder in breast cancer inhibition (pre-clinical study in DMBA-Induced Sprague Dawly Rats)

Science.gov (United States)

Bintari, S. H.; Parman, S.; Dafip, M.

2018-03-01

Breast cancer is a malignant disease, which lead to second cause of that after cervical cancer in women. To date, lots of drugs and supplement have been developed and consumed by patients. Shark bone is one of the supplements that might inhibit the proliferation of cancer cells. The application of shark bone powder for supplementation in breast cancer cases still becomes controversy; but until now people are still many who consume as a supplement. This study aimed to prove the potency of shark bone powder in the inhibition of breast cancer proliferation and to propose the possibility of its biological mechanism. The pre-clinical experimental study used a controlled posttest controlled design with 25 white rats strains of DML-induced Sprague-Dawley strains. The cancer markers observed were p53, AgNORs, VEGF, Bcl-2, and Cas-3. The test subjects were divided into 3 groups: control group and 2 treatment groups fed modified with 60% and 90% respectively. A pre-clinical trial of shark bone powder showed that there was significant inhibition for the DMBA-induced anti proliferation and breast cell cancer (p breast cancer proliferation lies in concentration 30mg/BB/day.

Utilization of blended learning to teach preclinical endodontics.

Science.gov (United States)

Maresca, Cristina; Barrero, Carlos; Duggan, Dereck; Platin, Enrique; Rivera, Eric; Hannum, Wallace; Petrola, Frank

2014-08-01

Blended learning (BL) is the integration of classroom learning with an online environment. The purpose of this study was to determine whether dental students who experienced BL in a preclinical endodontic course demonstrated better manual skills, conceptual knowledge, and learning experience compared to those experiencing traditional learning. All eighty-one students (100 percent) in a preclinical endodontics course agreed to participate and were assigned to either the traditional or BL group. A root canal procedure was used to determine the level of manual skills gained by each group. Pre- and post-intervention quizzes were given to all students to evaluate conceptual knowledge gained, and the students' perspectives on the methods were evaluated with a survey. The BL group scored better than the traditional group on the manual skills exercise at a statistically significant level (p=0.0067). There were no differences in the post-intervention quiz scores between the two groups, and the students' opinions were positive regarding BL. With BL, the students were able to learn and demonstrate dental skills at a high level.

Adjuvant bisphosphonates in early breast cancer

DEFF Research Database (Denmark)

Hadji, P; Coleman, R E; Wilson, C

2016-01-01

Bisphosphonates have been studied in randomised trials in early breast cancer to investigate their ability to prevent cancer treatment-induced bone loss (CTIBL) and reduce the risk of disease recurrence and metastasis. Treatment benefits have been reported but bisphosphonates do not currently have...... regulatory approval for either of these potential indications. This consensus paper provides a review of the evidence and offers guidance to breast cancer clinicians on the use of bisphosphonates in early breast cancer. Using the nominal group methodology for consensus, a systematic review of the literature...... was augmented by a workshop held in October 2014 for breast cancer and bone specialists to present and debate the available pre-clinical and clinical evidence for the use of adjuvant bisphosphonates. This was followed by a questionnaire to all members of the writing committee to identify areas of consensus...

Use of a collaborative tool to simplify the outsourcing of preclinical safety studies: an insight into the AstraZeneca-Charles River Laboratories strategic relationship.

Science.gov (United States)

Martin, Frederic D C; Benjamin, Amanda; MacLean, Ruth; Hollinshead, David M; Landqvist, Claire

2017-12-01

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.

Restoflex--a revolutionary change in preclinical practice for restorative dentistry and endodontics.

Science.gov (United States)

Jain, Shweta; Khaiser, Imran M; Thakur, Sophia; Jain, Shikha

2014-05-01

Preclinical exercises are very important for the dental students in order to master various dental techniques. The objective of this article is to introduce a new preclinical working model named Restoflex. It is especially designed for the students to carry out various restorative and endodontic procedures in an environment that closely simulate clinical situations. This will help them to provide a smooth transition from preclinical environment to the clinical one. It would also mean an increased confidence level and the efficiency with which the students would deal with their cases.

Preclinical Testing of an Oncolytic Parvovirus: Standard Protoparvovirus H-1PV Efficiently Induces Osteosarcoma Cell Lysis In Vitro

OpenAIRE

Carsten Geiss; Zoltán Kis; Barbara Leuchs; Monika Frank-Stöhr; Jörg R. Schlehofer; Jean Rommelaere; Christiane Dinsart; Jeannine Lacroix

2017-01-01

Osteosarcoma is the most frequent malignant disease of the bone. On the basis of early clinical experience in the 1960s with H-1 protoparvovirus (H-1PV) in osteosarcoma patients, this effective oncolytic virus was selected for systematic preclinical testing on various osteosarcoma cell cultures. A panel of five human osteosarcoma cell lines (CAL 72, H-OS, MG-63, SaOS-2, U-2OS) was tested. Virus oncoselectivity was confirmed by infecting non-malignant human neonatal fibroblasts and osteoblasts...

Collaborative learning in pre-clinical dental hygiene education.

Science.gov (United States)

Mueller-Joseph, Laura J; Nappo-Dattoma, Luisa

2013-04-01

Dental hygiene education continues to move beyond mastery of content material and skill development to learning concepts that promote critical-thinking and problem-solving skills. The purpose of this research was to evaluate the effectiveness of collaborative learning and determine the growth in intellectual development of 54 first-year dental hygiene students. The control group used traditional pre-clinical teaching and the experimental group used collaborative pedagogy for instrument introduction. All students were subjected to a post-test evaluating their ability to apply the principles of instrumentation. Intellectual development was determined using pre- and post-tests based on the Perry Scheme of Intellectual Development. Student attitudes were assessed using daily Classroom Assessment Activities and an end-of-semester departmental course evaluation. Findings indicated no significant difference between collaborative learning and traditional learning in achieving pre-clinical competence as evidenced by the students' ability to apply the principles of instrumentation. Advancement in intellectual development did not differ significantly between groups. Value added benefits of a collaborative learning environment as identified by the evaluation of student attitudes included decreased student reliance on authority, recognition of peers as legitimate sources of learning and increased self-confidence. A significant difference in student responses to daily classroom assessments was evident on the 5 days a collaborative learning environment was employed. Dental hygiene students involved in a pre-clinical collaborative learning environment are more responsible for their own learning and tend to have a more positive attitude toward the subject matter. Future studies evaluating collaborative learning in clinical dental hygiene education need to investigate the cost/benefit ratio of the value added outcomes of collaborative learning.

Stroke Lesions in a Large Upper Limb Rehabilitation Trial Cohort Rarely Match Lesions in Common Preclinical Models

Science.gov (United States)

Edwardson, Matthew A.; Wang, Ximing; Liu, Brent; Ding, Li; Lane, Christianne J.; Park, Caron; Nelsen, Monica A.; Jones, Theresa A; Wolf, Steven L; Winstein, Carolee J; Dromerick, Alexander W.

2017-01-01

Background Stroke patients with mild-moderate upper extremity (UE) motor impairments and minimal sensory and cognitive deficits provide a useful model to study recovery and improve rehabilitation. Laboratory-based investigators use lesioning techniques for similar goals. Objective Determine whether stroke lesions in an UE rehabilitation trial cohort match lesions from the preclinical stroke recovery models used to drive translational research. Methods Clinical neuroimages from 297 participants enrolled in the Interdisciplinary Comprehensive Arm Rehabilitation Evaluation (ICARE) study were reviewed. Images were characterized based on lesion type (ischemic or hemorrhagic), volume, vascular territory, depth (cortical gray matter, cortical white matter, subcortical), old strokes, and leukoaraiosis. Lesions were compared with those of preclinical stroke models commonly used to study upper limb recovery. Results Among the ischemic stroke participants, median infarct volume was 1.8 mL, with most lesions confined to subcortical structures (61%) including the anterior choroidal artery territory (30%) and the pons (23%). Of ICARE participants, stroke patients, but they represent a clinically and scientifically important subgroup. Compared to lesions in general stroke populations and widely-studied animal models of recovery, ICARE participants had smaller, more subcortically-based strokes. Improved preclinical-clinical translational efforts may require better alignment of lesions between preclinical and human stroke recovery models. PMID:28337932

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

Directory of Open Access Journals (Sweden)

Jody E. Hooper

2015-01-01

Full Text Available 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.

Kinetic modeling in pre-clinical positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Kuntner, Claudia [AIT Austrian Institute of Technology GmbH, Seibersdorf (Austria). Biomedical Systems, Health and Environment Dept.

2014-07-01

Pre-clinical positron emission tomography (PET) has evolved in the last few years from pure visualization of radiotracer uptake and distribution towards quantification of the physiological parameters. For reliable and reproducible quantification the kinetic modeling methods used to obtain relevant parameters of radiotracer tissue interaction are important. Here we present different kinetic modeling techniques with a focus on compartmental models including plasma input models and reference tissue input models. The experimental challenges of deriving the plasma input function in rodents and the effect of anesthesia are discussed. Finally, in vivo application of kinetic modeling in various areas of pre-clinical research is presented and compared to human data.

A systematic review of methodology applied during preclinical anesthetic neurotoxicity studies : important issues and lessons relevant to the design of future clinical research

NARCIS (Netherlands)

Disma, Nicola; Mondardini, Maria C.; Terrando, Niccolo; Absalom, Anthony R.; Bilotta, Federico

Preclinical evidence suggests that anesthetic agents harm the developing brain thereby causing long-term neurocognitive impairments. It is not clear if these findings apply to humans, and retrospective epidemiological studies thus far have failed to show definitive evidence that anesthetic agents

Functional network integrity presages cognitive decline in preclinical Alzheimer disease.

Science.gov (United States)

Buckley, Rachel F; Schultz, Aaron P; Hedden, Trey; Papp, Kathryn V; Hanseeuw, Bernard J; Marshall, Gad; Sepulcre, Jorge; Smith, Emily E; Rentz, Dorene M; Johnson, Keith A; Sperling, Reisa A; Chhatwal, Jasmeer P

2017-07-04

To examine the utility of resting-state functional connectivity MRI (rs-fcMRI) measurements of network integrity as a predictor of future cognitive decline in preclinical Alzheimer disease (AD). A total of 237 clinically normal older adults (aged 63-90 years, Clinical Dementia Rating 0) underwent baseline β-amyloid (Aβ) imaging with Pittsburgh compound B PET and structural and rs-fcMRI. We identified 7 networks for analysis, including 4 cognitive networks (default, salience, dorsal attention, and frontoparietal control) and 3 noncognitive networks (primary visual, extrastriate visual, motor). Using linear and curvilinear mixed models, we used baseline connectivity in these networks to predict longitudinal changes in preclinical Alzheimer cognitive composite (PACC) performance, both alone and interacting with Aβ burden. Median neuropsychological follow-up was 3 years. Baseline connectivity in the default, salience, and control networks predicted longitudinal PACC decline, unlike connectivity in the dorsal attention and all noncognitive networks. Default, salience, and control network connectivity was also synergistic with Aβ burden in predicting decline, with combined higher Aβ and lower connectivity predicting the steepest curvilinear decline in PACC performance. In clinically normal older adults, lower functional connectivity predicted more rapid decline in PACC scores over time, particularly when coupled with increased Aβ burden. Among examined networks, default, salience, and control networks were the strongest predictors of rate of change in PACC scores, with the inflection point of greatest decline beyond the fourth year of follow-up. These results suggest that rs-fcMRI may be a useful predictor of early, AD-related cognitive decline in clinical research settings. © 2017 American Academy of Neurology.

Experimental design and reporting standards for improving the internal validity of pre-clinical studies in the field of pain: Consensus of the IMI-Europain consortium

DEFF Research Database (Denmark)

Knopp, K.L.; Stenfors, C.; Baastrup, Cathrine Søndergaard

2015-01-01

that recommendations on how to improve these factors are warranted. Methods Members of Europain, a pain research consortium funded by the European Innovative Medicines Initiative (IMI), developed internal recommendations on how to improve the reliability of pre-clinical studies between laboratories. This guidance...... and conduct, and data analysis and interpretation. Key principles such as sample size calculation, a priori definition of a primary efficacy measure, randomization, allocation concealments, and blinding are discussed. In addition, considerations of how stress and normal rodent physiology impact outcome...... development in order to estimate possible publication bias is discussed. Conclusions More systematic research is needed to analyze how inadequate internal validity and/or experimental bias may impact reproducibility across pre-clinical pain studies. Addressing the potential threats to internal validity...

A crowdsourcing model for creating preclinical medical education study tools.

Science.gov (United States)

Bow, Hansen C; Dattilo, Jonathan R; Jonas, Andrea M; Lehmann, Christoph U

2013-06-01

During their preclinical course work, medical students must memorize and recall substantial amounts of information. Recent trends in medical education emphasize collaboration through team-based learning. In the technology world, the trend toward collaboration has been characterized by the crowdsourcing movement. In 2011, the authors developed an innovative approach to team-based learning that combined students' use of flashcards to master large volumes of content with a crowdsourcing model, using a simple informatics system to enable those students to share in the effort of generating concise, high-yield study materials. The authors used Google Drive and developed a simple Java software program that enabled students to simultaneously access and edit sets of questions and answers in the form of flashcards. Through this crowdsourcing model, medical students in the class of 2014 at the Johns Hopkins University School of Medicine created a database of over 16,000 questions that corresponded to the Genes to Society basic science curriculum. An analysis of exam scores revealed that students in the class of 2014 outperformed those in the class of 2013, who did not have access to the flashcard system, and a survey of students demonstrated that users were generally satisfied with the system and found it a valuable study tool. In this article, the authors describe the development and implementation of their crowdsourcing model for creating study materials, emphasize its simplicity and user-friendliness, describe its impact on students' exam performance, and discuss how students in any educational discipline could implement a similar model of collaborative learning.

Longitudinal trends and subgroup analysis in publication patterns for preclinical data of newly approved drugs.

Science.gov (United States)

Köster, Ursula; Nolte, Ingo; Michel, Martin C

2016-02-01

Having observed a large variation in the number and type of original preclinical publications for newly registered drugs, we have explored whether longitudinal trends and/or factors specific for certain drugs or their manufacturers may explain such variation. Our analysis is based on 1954 articles related to 170 newly approved drugs. The number of preclinical publications per compound declined from a median of 10.5 in 1991 to 3 in 2011. A similar trend was observed for the number of in vivo studies in general, but not in the subset of in vivo studies in animal models of disease. The percentage of compounds with studies using isolated human cells or cell lines almost doubled over time from 37 to 72%. Number of publications did not exhibit major differences between compounds intended for human versus veterinary use, therapeutic areas, small molecules versus biologicals, or innovator versus follow-up compounds; however, some companies may publish fewer studies per compound than others. However, there were qualitative differences in the types of models being used depending on the therapeutic area; specifically, compounds for use in oncology very often used isolated cells and cell lines, often from human origin. We conclude that the large variation in number and type of reported preclinical data is not easily explained. We propose that pharmaceutical companies should consistently provide a comprehensive documentation of the preclinical data they generate as part of their development programs in the public domain to enable a better understanding of the drugs they intend to market.

Monochromatic minibeam radiotherapy: theoretical and experimental dosimetry for preclinical treatment plans

Energy Technology Data Exchange (ETDEWEB)

Deman, P; Vautrin, M; Stupar, V; Barbier, E L; Elleaume, H; Esteve, F; Adam, J F, E-mail: adam@esrf.fr [INSERM, U836, BP 170, Grenoble Cedex 9, F-38042 (France)

2011-07-21

Monochromatic x-ray minibeam radiotherapy is a new radiosurgery approach based on arrays of submillimetric interlaced planar x-ray beams. The aim of this study was to characterize the dose distributions obtained with this new modality when being used for preclinical trials. Monte Carlo simulations were performed in water phantoms. Percentage depth-dose curves and dose profiles were computed for single incidences and interleaved incidences of 80 keV planar x-ray minibeam (0.6 x 5 mm) arrays. Peak to valley dose ratios were also computed at various depths for an increasing number of minibeams. 3D experimental polymer gel (nPAG) dosimetry measurements were performed using MRI devices designed for small animal imaging. These very high spatial resolution (50 {mu}m) dose maps were compared to the simulations. Preclinical minibeams dose distributions were fully characterized. Experimental dosimetry correlated well with Monte Carlo calculations (Student t-tests: p > 0.1). F98 tumor-bearing rats were also irradiated with interleaved minibeams (80 keV, prescribed dose: 25 Gy). This associated preclinical trial serves as a proof of principle of the technique. The mean survival time of irradiated glioma-bearing rats increased significantly, when compared to the untreated animals (59.6 {+-} 2.8 days versus 28.25 {+-} 0.75 days, p < 0.001).

The preclinical discovery and development of quetiapine for the treatment of mania and depression.

Science.gov (United States)

Miranda, Aline Silva de; Moreira, Fabrício A; Teixeira, Antônio Lúcio

2017-05-01

Bipolar disorder is a chronic disabling condition characterized by alternating manic and depressive episodes. Bipolar disorder has been associated with functional impairment, poor quality of life, morbidity and mortality. Despite its significant clinical, social and economic burden, treatment options for bipolar disorder are still limited. Several clinical trials have shown efficacy of the atypical antipsychotic quetiapine (QTP) in the treatment of this condition. However, the mechanisms underlying the antidepressant and anti-manic effects of QTP remain poorly understood. Areas covered: The article provides the emerging evidence from pre-clinical studies regarding the antidepressant and anti-manic mechanisms of action of QTP. In combination with its primary active metabolite norquetiapine, QTP modulates several neurotransmitter systems, including serotonin, dopamine, noradrenaline and histamine. QTP also seems to influence mediators of the immune system. Expert opinion: Pre-clinical studies have provided valuable information on the potential antidepressant mechanisms of action of QTP, but pre-clinical studies on QTP's anti-manic effects are still scarce. A major problem refers to the lack of valid experimental models for bipolar disorder. Additionally, immune and genetic based studies are largely descriptive. The role of the QTP metabolite norquetiapine in modulating non-neurotransmitter systems also needs to be further addressed.

The Role of Three-Dimensional Scaffolds in Treating Long Bone Defects: Evidence from Preclinical and Clinical Literature-A Systematic Review.

Science.gov (United States)

Roffi, Alice; Krishnakumar, Gopal Shankar; Gostynska, Natalia; Kon, Elizaveta; Candrian, Christian; Filardo, Giuseppe

2017-01-01

Long bone defects represent a clinical challenge. Bone tissue engineering (BTE) has been developed to overcome problems associated with conventional methods. The aim of this study was to assess the BTE strategies available in preclinical and clinical settings and the current evidence supporting this approach. A systematic literature screening was performed on PubMed database, searching for both preclinical (only on large animals) and clinical studies. The following string was used: "(Scaffold OR Implant) AND (Long bone defect OR segmental bone defect OR large bone defect OR bone loss defect)." The search retrieved a total of 1573 articles: 51 preclinical and 4 clinical studies were included. The great amount of preclinical papers published over the past few years showed promising findings in terms of radiological and histological evidence. Unfortunately, this in vivo situation is not reflected by a corresponding clinical impact, with few published papers, highly heterogeneous and with small patient populations. Several aspects should be further investigated to translate positive preclinical findings into clinical protocols: the identification of the best biomaterial, with both biological and biomechanical suitable properties, and the selection of the best choice between cells, GFs, or their combination through standardized models to be validated by randomized trials.

Preparation and preclinical pharmacological study on a novel bone imaging agent 99mTc-EMIDP

International Nuclear Information System (INIS)

Lin Jianguo; Luo Shineng; Chen Chuanqing; Qiu Ling; Wang Yan; Cheng Wen; Ye Wanzhong; Xia Yongmei

2010-01-01

A novel zoledronic acid (ZL) derivative, 1-hydroxy-2-(2-ethyl-4-methyl-1H-imidazol-1-yl)ethane-1,1-diyldiphosphonic acid (EMIDP), was prepared and labeled with 99m Tc successfully in a high labeling yield and good stability in vitro. The preclinical pharmacological properties of 99m Tc-EMIDP were investigated and compared with 99m Tc-MDP and 99m Tc-ZL. The studies of biodistribution in mice and SPECT bone imaging of the rabbit suggest that 99m Tc-EMIDP has highly selective uptake in the skeletal system and rapid clearance in the soft tissues. The present findings indicate that 99m Tc-EMIDP holds great potential for bone scintigraphy.

Preclinical Studies for Cartilage Repair

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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

Marker for the pre-clinical development of bone substitute materials

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de Wild Michael

2017-09-01

Full Text Available Thin mechanically stable Ti-cages have been developed for the in-vivo application as X-ray and histology markers for the optimized evaluation of pre-clinical performance of bone graft materials. A metallic frame defines the region of interest during histological investigations and supports the identification of the defect site. This standardization of the procedure enhances the quality of pre-clinical experiments. Different models of thin metallic frameworks were designed and produced out of titanium by additive manufacturing (Selective Laser Melting. The productibility, the mechanical stability, the handling and suitability of several frame geometries were tested during surgery in artificial and in ex-vivo bone before a series of cages was preclinically investigated in the female Göttingen minipigs model. With our novel approach, a flexible process was established that can be adapted to the requirements of any specific animal model and bone graft testing.

Atomoxetine for hoarding disorder: A pre-clinical and clinical investigation.

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Grassi, Giacomo; Micheli, Laura; Di Cesare Mannelli, Lorenzo; Compagno, Elisa; Righi, Lorenzo; Ghelardini, Carla; Pallanti, Stefano

2016-12-01

Despite several studies suggested that inattention and impulsivity-compulsivity could represent two core dimensions of hoarding disorder (HD), only a small case series study investigated the effectiveness of attention-deficit-hyperactivity-disorder (ADHD) medications in HD. The aim of the present study was to target attentional and inhibitory control networks in HD patients through the ADHD medication atomoxetine, moving from a preclinical investigation on an animal model of compulsive-like behavior (marble burying test) to a clinical investigation on both medicated and unmedicated patients with a primary diagnosis of HD without ADHD. Our preclinical investigation showed that acute administration of atomoxetine significantly reduced the compulsive-like behaviours of mice in the marble burying test without affecting neither locomotor activity and coordination nor exploration behaviours. When compared, atomoxetine and fluoxetine showed similar effects on the marble burying test. However, fluoxetine impaired both locomotor and exploratory activity. In our clinical investigation 12 patients were enrolled and 11 patients completed an open trial with atomoxetine at flexible dose (40-80 mg) for 12 weeks. At the endpoint the mean UCLA Hoarding Severity Scale score decreased by 41.3% for the whole group (p = 0003). Six patients were classified as full responders (mean symptom reduction of 57.2%) and three patients as partial responders (mean symptom reduction of 27.3%). Inattentive and impulsivity symptoms showed a significant mean score reduction of 18.5% from baseline to the endpoint (F (1,9) = 20.9, p = 0.0013). Hoarding symptoms improvement was correlated to reduction of patients' disability and increased in their global functioning. These preclinical and clinical data suggest that atomoxetine may be effective for HD and therefore should be considered for future controlled trials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biomarkers in the early diagnosis of Parkinson's disease

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CHEN Sheng-di

2013-08-01

Full Text Available Parkinson's disease (PD is a chronic and progressive neurodegenerative disorder. It has become clear that PD can have a preclinical phase, a period during which neurodegeneration has already begun years before the onset of typical motor symptoms. Consequently, if the early neurodegeneration in PD can be timely diagnosed, it will significantly slow down the progression of the disease and improve the quality of life. To date, there is no fully reliable and validated biomarker for the early diagnosis of PD, but some promising biomarker candidates exist.

Tendinopathies and platelet-rich plasma (PRP: from pre-clinical experiments to therapeutic use

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Kaux JF

2015-05-01

Full Text Available Objectives: The restorative properties of platelets, through the local release of growth factors, are used in various medical areas. This article reviews fundamental and clinical research relating to platelet-rich plasma applied to tendinous lesions. Materials and method: Articles in French and English, published between 1 January 2012 and 31 December 2014. dealing with PRP and tendons were searched for using the Medline and Scopus data bases. Results: Forty-seven articles were identified which addressed pre-clinical and clinical studies: 27 relating to in vitro and in vivo animal studies and 20 relating to human studies. Of these, five addressed lateral epicondylitis, two addressed rotator cuff tendinopathies, ten dealt with patellar tendinopathies and three looked at Achilles tendinopathies. Conclusions: The majority of pre-clinical studies show that PRP stimulates the tendon's healing process. However, clinical series remain more controversial and level 1, controlled, randomised studies are still needed.

Preclinical Models in Chimeric Antigen Receptor-Engineered T-Cell Therapy.

Science.gov (United States)

Siegler, Elizabeth Louise; Wang, Pin

2018-05-01

Cancer immunotherapy has enormous potential in inducing long-term remission in cancer patients, and chimeric antigen receptor (CAR)-engineered T cells have been largely successful in treating hematological malignancies in the clinic. CAR-T therapy has not been as effective in treating solid tumors, in part due to the immunosuppressive tumor microenvironment. Additionally, CAR-T therapy can cause dangerous side effects, including off-tumor toxicity, cytokine release syndrome, and neurotoxicity. Animal models of CAR-T therapy often fail to predict such adverse events and frequently overestimate the efficacy of the treatment. Nearly all preclinical CAR-T studies have been performed in mice, including syngeneic, xenograft, transgenic, and humanized mouse models. Recently, a few studies have used primate models to mimic clinical side effects better. To date, no single model perfectly recapitulates the human immune system and tumor microenvironment, and some models have revealed CAR-T limitations that were contradicted or missed entirely in other models. Careful model selection based on the primary goals of the study is a crucial step in evaluating CAR-T treatment. Advancements are being made in preclinical models, with the ultimate objective of providing safer, more effective CAR-T therapy to patients.

Radiochemical studies, pre-clinical investigation and preliminary clinical evaluation of "1"7"0Tm-EDTMP prepared using in-house freeze-dried EDTMP kit

International Nuclear Information System (INIS)

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

2017-01-01

The objective of the present work is to formulate "1"7"0Tm-EDTMP using an in-house freeze-dried EDTMP kit and evaluate its potential as a bone pain palliation agent. Patient dose of "1"7"0Tm-EDTMP was prepared with high radiochemical purity using the lyophilized kit at room temperature within 15 min. 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. - Highlights: • Formulation of patient dose of "1"7"0Tm-EDTMP using freeze-dried EDTMP kit. • Radiochemical studies and pre-clinical evaluation of the agent in animal model. • Clinical evaluation in eight cancer patients with disseminated skeletal metastases.

Promoting evidence based medicine in preclinical medical students via a federated literature search tool.

Science.gov (United States)

Keim, Samuel Mark; Howse, David; Bracke, Paul; Mendoza, Kathryn

2008-01-01

Medical educators are increasingly faced with directives to teach Evidence Based Medicine (EBM) skills. Because of its nature, integrating fundamental EBM educational content is a challenge in the preclinical years. To analyse preclinical medical student user satisfaction and feedback regarding a clinical EBM search strategy. The authors introduced a custom EBM search option with a self-contained education structure to first-year medical students. The implementation took advantage of a major curricular change towards case-based instruction. Medical student views and experiences were studied regarding the tool's convenience, problems and the degree to which they used it to answer questions raised by case-based instruction. Surveys were completed by 70% of the available first-year students. Student satisfaction and experiences were strongly positive towards the EBM strategy, especially of the tool's convenience and utility for answering issues raised during case-based learning sessions. About 90% of the students responded that the tool was easy to use, productive and accessed for half or more of their search needs. This study provides evidence that the integration of an educational EBM search tool can be positively received by preclinical medical students.

SU-E-T-606: Performance of MR-Based 3D FXG Dosimetry for Preclinical Irradiation

Energy Technology Data Exchange (ETDEWEB)

Welch, M [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Jaffray, D [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, ON (Canada); Department of Radiation Oncology, University of Toronto, Toronto, ON (Canada); TECHNA Institute for the Advancement of Technology for Health, Toronto, ON (Canada)

2015-06-15

Purpose: Technological advances have revolutionized preclinical radiation research to enable precise radiation delivery in preclinical models. Kilovoltage x-rays and complex geometries in preclinical radiation studies challenge conventional dosimetry methods. Previously developed gel-based dosimetry provides a viable means of accommodating complex geometries and accurately reporting dose at kV energies. This paper will describe the development and evaluation of gel-based ferrous xylenol-orange (FXG) dosimetry using a 7T preclinical imaging system. Methods: To confirm water equivalence, Zeff values were calculated for the FXG material, water and ICRU defined soft tissue. Proton T1 relaxivity response in FXG was measured using a preclinical 7T MR and a small animal irradiator for a dose range of 1–22 Gy. FXG was contained in 50 ml centrifuge tubes and irradiated with a 225 kVp x-ray beam at a nominal dose rate of 2.3 Gy/min. Pre and post irradiation maps of the T1 relaxivity were collected using variable TR spin-echo imaging (TE 6.65 ms; TR 500, 750, 1000, 1500, 2000, 3000 and 5000 ms) with 2 mm thick slices, 0.325 mm/pixel, 3 averages and an acquisition time of 26 minutes. A linear fit to the change in relaxation rate (1/T1) for the delivered doses reported the gel sensitivity in units of ms{sup -1}Gy{sup -1}. Irradiation and imaging studies were repeated using three batches of gel over 72 hrs. Results: FXG has a Zeff of 3.8 for the 225 kVp spectrum used; differing from water and ICRU defined soft tissue by 0.5% and 2.5%, respectively. The average sensitivity for the FXG dosimeter was 31.5 ± 0.7 ms{sup -1}Gy{sup -1} (R{sup 2} = 0.9957) with a y-intercept of −29.4 ± 9.0 ms{sup -1}. Conclusion: Preliminary results for the FXG dosimeter properties, sensitivity, and dose linearity at preclinical energies is promising. Future work will explore anatomically relevant tissue inclusions to test MR performance. Student funding provided by The Terry Fox Foundation

Preclinical Immunomodulation by the Probiotic Bifidobacterium breve M-16V in Early Life.

Science.gov (United States)

Rigo-Adrover, Maria Del Mar; Franch, Àngels; Castell, Margarida; Pérez-Cano, Francisco José

2016-01-01

This study aimed to investigate the effect of supplementation with the probiotic Bifidobacterium breve M-16V on the maturation of the intestinal and circulating immune system during suckling. In order to achieve this purpose, neonatal Lewis rats were supplemented with the probiotic strain from the 6th to the 18th day of life. The animals were weighed during the study, and faecal samples were obtained and evaluated daily. On day 19, rats were euthanized and intestinal wash samples, mesenteric lymph node (MLN) cells, splenocytes and intraepithelial lymphocytes (IEL) were obtained. The probiotic supplementation in early life did not modify the growth curve and did not enhance the systemic immune maturation. However, it increased the proportion of cells bearing TLR4 in the MLN and IEL, and enhanced the percentage of the integrin αEβ7+ and CD62L+ cells in the MLN and that of the integrin αEβ7+ cells in the IEL, suggesting an enhancement of the homing process of naïve T lymphocytes to the MLN, and the retention of activated lymphocytes in the intraepithelial compartment. Interestingly, B. breve M-16V enhanced the intestinal IgA synthesis. In conclusion, supplementation with the probiotic strain B. breve M-16V during suckling improves the development of mucosal immunity in early life.

Preclinical Immunomodulation by the Probiotic Bifidobacterium breve M-16V in Early Life.

Directory of Open Access Journals (Sweden)

Maria Del Mar Rigo-Adrover

Full Text Available This study aimed to investigate the effect of supplementation with the probiotic Bifidobacterium breve M-16V on the maturation of the intestinal and circulating immune system during suckling. In order to achieve this purpose, neonatal Lewis rats were supplemented with the probiotic strain from the 6th to the 18th day of life. The animals were weighed during the study, and faecal samples were obtained and evaluated daily. On day 19, rats were euthanized and intestinal wash samples, mesenteric lymph node (MLN cells, splenocytes and intraepithelial lymphocytes (IEL were obtained. The probiotic supplementation in early life did not modify the growth curve and did not enhance the systemic immune maturation. However, it increased the proportion of cells bearing TLR4 in the MLN and IEL, and enhanced the percentage of the integrin αEβ7+ and CD62L+ cells in the MLN and that of the integrin αEβ7+ cells in the IEL, suggesting an enhancement of the homing process of naïve T lymphocytes to the MLN, and the retention of activated lymphocytes in the intraepithelial compartment. Interestingly, B. breve M-16V enhanced the intestinal IgA synthesis. In conclusion, supplementation with the probiotic strain B. breve M-16V during suckling improves the development of mucosal immunity in early life.

Perceptions of Teaching Methods for Preclinical Oral Surgery: A Comparison with Learning Styles.

Science.gov (United States)

Omar, Esam

2017-01-01

Dental extraction is a routine part of clinical dental practice. For this reason, understanding the way how students' extraction knowledge and skills development are important. To date, there is no accredited statement about the most effective method for the teaching of exodontia to dental students. Students have different abilities and preferences regarding how they learn and process information. This is defined as learning style. In this study, the effectiveness of active learning in the teaching of preclinical oral surgery was examined. The personality type of the groups involved in this study was determined, and the possible effect of personality type on learning style was investigated. This study was undertaken over five years from 2011 to 2015. The sample consisted of 115 students and eight staff members. Questionnaires were submitted by 68 students and all eight staff members involved. Three measures were used in the study: The Index of Learning Styles (Felder and Soloman, 1991), the Myers-Briggs Type Indicator (MBTI), and the styles of learning typology (Grasha and Hruska-Riechmann). Findings indicated that demonstration and minimal clinical exposure give students personal validation. Frequent feedback on their work is strongly indicated to build the cognitive, psychomotor, and interpersonal skills needed from preclinical oral surgery courses. Small group cooperative active learning in the form of demonstration and minimal clinical exposure that gives frequent feedback and students' personal validation on their work is strongly indicated to build the skills needed for preclinical oral surgery courses.

Optimised and rapid pre-clinical screening in the SOD1(G93A) transgenic mouse model of amyotrophic lateral sclerosis (ALS).

Science.gov (United States)

Mead, Richard J; Bennett, Ellen J; Kennerley, Aneurin J; Sharp, Paul; Sunyach, Claire; Kasher, Paul; Berwick, Jason; Pettmann, Brigitte; Battaglia, Guiseppe; Azzouz, Mimoun; Grierson, Andrew; Shaw, Pamela J

2011-01-01

The human SOD1(G93A) transgenic mouse has been used extensively since its development in 1994 as a model for amyotrophic lateral sclerosis (ALS). In that time, a great many insights into the toxicity of mutant SOD1 have been gained using this and other mutant SOD transgenic mouse models. They all demonstrate a selective toxicity towards motor neurons and in some cases features of the pathology seen in the human disease. These models have two major drawbacks. Firstly the generation of robust preclinical data in these models has been highlighted as an area for concern. Secondly, the amount of time required for a single preclinical experiment in these models (3-4 months) is a hurdle to the development of new therapies. We have developed an inbred C57BL/6 mouse line from the original mixed background (SJLxC57BL/6) SOD1(G93A) transgenic line and show here that the disease course is remarkably consistent and much less prone to background noise, enabling reduced numbers of mice for testing of therapeutics. Secondly we have identified very early readouts showing a large decline in motor function compared to normal mice. This loss of motor function has allowed us to develop an early, sensitive and rapid screening protocol for the initial phases of denervation of muscle fibers, observed in this model. We describe multiple, quantitative readouts of motor function that can be used to interrogate this early mechanism. Such an approach will increase throughput for reduced costs, whilst reducing the severity of the experimental procedures involved.

Preclinical studies of lymphographic applilcation of 99mTc-dextrans of different molecular weight

International Nuclear Information System (INIS)

Lamka, J.; Kvetina, J.; Kafka, P.

1986-01-01

In a preclinical investigation on rabbits the distribution was tested of dextrans of two molecular weights (40,000 and 70,000) with regard to their use as a carrier in indirect lymphography. The tests showed that both 99m Tc-dextrans achieve high ratios of lymph/blood levels. It is suggested that for clinical work it is better to use dextran with a molecular weight of 70,000 than that with a molecular weight of 40,000. (author)

Comparative Plasma Exposure and Lung Distribution of Two Human Use Commercial Azithromycin Formulations Assessed in Murine Model: A Preclinical Study

OpenAIRE

Rivulgo, Virginia Margarita; Sparo, Mónica; Ceci, Mónica; Fumuso, Elida; Confalonieri, Alejandra; Delpech, Gastón; Sanchez Bruni, Sergio Fabian

2016-01-01

Azithromycin(AZM)therapeutic failure and relapses of patients treated with generic -35 formulations have been observed in clinical practice.The main goal of this research was 36 to compare in a pre-clinical study the serum exposure and lung tissue concentrationof 37 two commercial formulations AZM-based in murine model. The current study involved 38 264 healthy Balb-C.Mice were divided in two groups (n=44): Animals of Group A 39 (Reference Formulation ?R-) were orally treated with AZM suspens...

Curcumin nanoformulations : A review of pharmaceutical properties and preclinical studies and clinical data related to cancer treatment

NARCIS (Netherlands)

Naksuriya, Ornchuma; Okonogi, Siriporn; Schiffelers, Raymond M.|info:eu-repo/dai/nl/212909509; Hennink, Wim E.|info:eu-repo/dai/nl/070880409

2014-01-01

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

Spinal Cord Stimulation for Treating Chronic Pain: Reviewing Preclinical and Clinical Data on Paresthesia-Free High-Frequency Therapy.

Science.gov (United States)

Chakravarthy, Krishnan; Richter, Hira; Christo, Paul J; Williams, Kayode; Guan, Yun

2018-01-01

Traditional spinal cord stimulation (SCS) requires that paresthesia overlaps chronic painful areas. However, the new paradigm high-frequency SCS (HF-SCS) does not rely on paresthesia. A review of preclinical and clinical studies regarding the use of paresthesia-free HF-SCS for various chronic pain states. We reviewed available literatures on HF-SCS, including Nevro's paresthesia-free ultra high-frequency 10 kHz therapy (HF10-SCS). Data sources included relevant literature identified through searches of PubMed, MEDLINE/OVID, and SCOPUS, and manual searches of the bibliographies of known primary and review articles. The primary goal is to describe the present developing conceptions of preclinical mechanisms of HF-SCS and to review clinical efficacy on paresthesia-free HF10-SCS for various chronic pain states. HF10-SCS offers a novel pain reduction tool without paresthesia for failed back surgery syndrome and chronic axial back pain. Preclinical findings indicate that potential mechanisms of action for paresthesia-free HF-SCS differ from those of traditional SCS. To fully understand and utilize paresthesia-free HF-SCS, mechanistic study and translational research will be very important, with increasing collaboration between basic science and clinical communities to design better trials and optimize the therapy based on mechanistic findings from effective preclinical models and approaches. Future research in these vital areas may include preclinical and clinical components conducted in parallel to optimize the potential of this technology. © 2017 International Neuromodulation Society.

Preclinical and phase I studies of monoclonal antibodies in melanoma: Application to boron neutron capture therapy of melanoma

International Nuclear Information System (INIS)

Hersey, P.

1989-01-01

Monoclonal antibodies (MAbs) provide an attractive method of selectively localizing sufficient boron atoms around tumour cells to capture neutrons. Assuming that 10(8)-10(10) 10B atoms are needed for one capture event and that 10(3)-10(4) atoms can be coupled to each antibody molecule, then 10(5)-10(6) antibody molecules gathered on an individual cell will destroy that cell. Binding to normal tissues, on the other hand, would need to be at least 20-fold less than that to tumour tissues to avoid toxic effects of neutrons on surrounding tissues. Preclinical studies in animals show that several MAbs may bind to melanoma cells in sufficient quantities in vitro to localize the required amount of boron per cell. Whether this will occur in vivo, however, may depend not only on antigen density but a variety of other properties of the tumour cells and MAbs. These include the Ig class and affinity of the antibody and whether the antibody is internalized into the tumour cell. The ratio of uptake between tumour and normal tissue is governed by such factors as the percentage of tumour cells within a tumour expressing the antigen and whether the MAb react with normal tissues. Use of Fab or F(ab)2 preparations of the MAb may increase the uptake ratio by preventing uptake of MAb by cells with Fc receptors. In contrast to preclinical animal studies, tumour/normal tissue uptake ratios in phase I studies in humans have been disappointingly low.80 references

[Working memory for music in patients with mild cognitive impairment and early stage Alzheimer's disease].

Science.gov (United States)

Kerer, Manuela; Marksteiner, Josef; Hinterhuber, Hartmann; Mazzola, Guerino; Kemmler, Georg; Bliem, Harald R; Weiss, Elisabeth M

2013-01-01

A variety of studies demonstrated that some forms of memory for music are spared in dementia, but only few studies have investigated patients with early stages of dementia. In this pilot-study we tested working memory for music in patients with mild cognitive impairment (MCI) and early stage Alzheimer's disease (AD) with a newly created test. The test probed working memory using 7 gradually elongated tone-lines and 6 chords which were each followed by 3 similar items and 1 identical item. The participants of the study, namely 10 patients with MCI, 10 patients with early stage AD and 23 healthy subjects were instructed to select the identical tone-line or chord. Subjects with MCI and early AD showed significantly reduced performance than controls in most of the presented tasks. In recognizing chords MCI- participants surprisingly showed an unimpaired performance. The gradual increase of the impairment during the preclinical phase of AD seems to spare this special ability in MCI.

Concise Review: Mesenchymal Stem (Stromal) Cells: Biology and Preclinical Evidence for Therapeutic Potential for Organ Dysfunction Following Trauma or Sepsis.

Science.gov (United States)

Matthay, Michael A; Pati, Shibani; Lee, Jae-Woo

2017-02-01

Several experimental studies have provided evidence that bone-marrow derived mesenchymal stem (stromal) cells (MSC) may be effective in treating critically ill surgical patients who develop traumatic brain injury, acute renal failure, or the acute respiratory distress syndrome. There is also preclinical evidence that MSC may be effective in treating sepsis-induced organ failure, including evidence that MSC have antimicrobial properties. This review considers preclinical studies with direct relevance to organ failure following trauma, sepsis or major infections that apply to critically ill patients. Progress has been made in understanding the mechanisms of benefit, including MSC release of paracrine factors, transfer of mitochondria, and elaboration of exosomes and microvesicles. Regardless of how well they are designed, preclinical studies have limitations in modeling the complexity of clinical syndromes, especially in patients who are critically ill. In order to facilitate translation of the preclinical studies of MSC to critically ill patients, there will need to be more standardization regarding MSC production with a focus on culture methods and cell characterization. Finally, well designed clinical trials will be needed in critically ill patient to assess safety and efficacy. Stem Cells 2017;35:316-324. © 2016 AlphaMed Press.

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

Science.gov (United States)

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.

[Does the transition to clinical training change students' perception of career choice, physician's character and preclinical studies?].

Science.gov (United States)

Lotan, Eyal; Kimhi, Oded; Lishner, Michael; Notzer, Netta

2010-04-01

In Israel, the transition to clinical training in hospitals is the first direct encounter of the medical student with the reality of the profession. This is a significant socialization step for his upcoming professional decisions. This study aimed to identify how this encounter influences students' perceptions of career choice, physician's character and preclinical studies. Fourth year Israeli medical students at the Tel Aviv University voluntarily completed a questionnaire before and after their first clinical clerkship. The questionnaire was comprised of 30 5-point Likert scale statements and 3 multiple choice questions with the possibility to add remarks. The random response rate was 90% (81/90) before the clerkship and 82% (90/110) at its end. Results indicate that the students are satisfied with their medical studies at both junctures. However, after the clerkship, 23% of the students consider alternatives to clinical medicine compared with only 6% before, and 16% would rethink studying medicine. Physicians are perceived as professional, compassionate, respectful to colleagues and actively participating in students' education. Physicians' levels of workload and bitterness are evaluated as high and moderate, respectively, while their levels of reward and satisfaction with medicine are evaluated as low and moderate, respectively. Their evaluation of the contribution of preclinical studies as preparation for clinical studies had not changed after the clerkship and was moderate, and earlier exposure to patients and clinical relevancy of the learned subjects were preferred. The students enter the medical world highly satisfied, and this feeling shall be maintained until the stage of being independent physicians and choosing their specialties. The picture that evolved, in which a high proportion of the students consider alternatives to clinical medicine, is disappointing. Educators should be aware of their role model function not only in knowledge and skills, but

Role of SimMan in teaching clinical skills to preclinical medical students

Directory of Open Access Journals (Sweden)

Swamy Meenakshi

2013-02-01

Full Text Available Abstract Background Simulation training has potential in developing clinical skills in pre-clinical medical students, but there is little evidence on its effectiveness. Methods Twenty four first year graduate entry preclinical medical students participated in this crossover study. They were divided into two groups, one performed chest examination on each other and the other used SimMan. The groups then crossed over. A pretest, midtest and post-test was conducted in which the students answered the same questionnaire with ten questions on knowledge, and confidence levels rated using a 5 point Likert scale. They were assessed formatively using the OSCE marking scheme. At the end of the session, 23 students completed a feedback questionnaire. Data was analyzed using one-way ANOVA and independent t-test. Results When the two groups were compared, there was no significant difference in the pretest and the post-test scores on knowledge questions whereas the midtest scores increased significantly (P Mean confidence ratings increased from the pretest to midtest and then further in the post-test for both groups. Their confidence ratings increased significantly in differentiating between normal and abnormal signs [Group starting with SimMan, between pretest and midtest (P= 0.01 and group starting with peer examination, between midtest and post-test (P=0.02]. When the students’ ability to perform examination on each other for both groups was compared, there was a significant increase in the scores of the group starting with SimMan (P=0.007. Conclusions This pilot study demonstrated a significant improvement in the students’ knowledge and competence to perform chest examination after simulation with an increase in the student’s perceived levels of confidence. Feedback from the students was extremely positive. SimMan acts as a useful adjunct to teach clinical skills to preclinical medical students by providing a simulated safe environment and thus aids

PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR (PPAR) AGONISTS AS PROMISING NEW MEDICATIONS FOR DRUG ADDICTION: PRECLINICAL EVIDENCE

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Foll, Bernard Le; Ciano, Patricia Di; Panlilio, Leigh V.; Goldberg, Steven R.; Ciccocioppo, Roberto

2013-01-01

This review examines the growing literature on the role of peroxisome proliferator-activated receptors (PPARs) in addiction. There are two subtypes of PPAR receptors that have been studied in addiction: PPAR-α and PPAR-γ. The role of each PPAR subtype in common models of addictive behavior, mainly pre-clinical models, is summarized. In particular, studies are reviewed that investigated the effects of PPAR-α agonists on relapse, sensitization, conditioned place preference, withdrawal and drug intake, and effects of PPAR-γ agonists on relapse, withdrawal and drug intake. Finally, studies that investigated the effects of PPAR agonists on neural pathways of addiction are reviewed. Taken together this preclinical data indicates that PPAR agonists are promising new medications for drug addiction treatment. PMID:23614675

Preclinical QSP Modeling in the Pharmaceutical Industry: An IQ Consortium Survey Examining the Current Landscape

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Wu, Fan; Bansal, Loveleena; Bradshaw‐Pierce, Erica; Chan, Jason R.; Liederer, Bianca M.; Mettetal, Jerome T.; Schroeder, Patricia; Schuck, Edgar; Tsai, Alice; Xu, Christine; Chimalakonda, Anjaneya; Le, Kha; Penney, Mark; Topp, Brian; Yamada, Akihiro

2018-01-01

A cross‐industry survey was conducted to assess the landscape of preclinical quantitative systems pharmacology (QSP) modeling within pharmaceutical companies. This article presents the survey results, which provide insights on the current state of preclinical QSP modeling in addition to future opportunities. Our results call attention to the need for an aligned definition and consistent terminology around QSP, yet highlight the broad applicability and benefits preclinical QSP modeling is currently delivering. PMID:29349875

Radiation dosimetry of the α4β2 nicotinic receptor ligand (+-[18F]flubatine, comparing preclinical PET/MRI and PET/CT to first-in-human PET/CT results

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Mathias Kranz

2016-10-01

Full Text Available Abstract Background Both enantiomers of [18F]flubatine are new radioligands for neuroimaging of α4β2 nicotinic acetylcholine receptors with positron emission tomography (PET exhibiting promising pharmacokinetics which makes them attractive for different clinical questions. In a previous preclinical study, the main advantage of (+-[18F]flubatine compared to (−-[18F]flubatine was its higher binding affinity suggesting that (+-[18F]flubatine might be able to detect also slight reductions of α4β2 nAChRs and could be more sensitive than (−-[18F]flubatine in early stages of Alzheimer’s disease. To support the clinical translation, we investigated a fully image-based internal dosimetry approach for (+-[18F]flubatine, comparing mouse data collected on a preclinical PET/MRI system to piglet and first-in-human data acquired on a clinical PET/CT system. Time-activity curves (TACs were obtained from the three species, the animal data extrapolated to human scale, exponentially fitted and the organ doses (OD, and effective dose (ED calculated with OLINDA. Results The excreting organs (urinary bladder, kidneys, and liver receive the highest organ doses in all species. Hence, a renal/hepatobiliary excretion pathway can be assumed. In addition, the ED conversion factors of 12.1 μSv/MBq (mice, 14.3 μSv/MBq (piglets, and 23.0 μSv/MBq (humans were calculated which are well within the order of magnitude as known from other 18F-labeled radiotracers. Conclusions Although both enantiomers of [18F]flubatine exhibit different binding kinetics in the brain due to the respective affinities, the effective dose revealed no enantiomer-specific differences among the investigated species. The preclinical dosimetry and biodistribution of (+-[18F]flubatine was shown and the feasibility of a dose assessment based on image data acquired on a small animal PET/MR and a clinical PET/CT was demonstrated. Additionally, the first-in-human study confirmed the tolerability

Perceptions of Teaching Methods for Preclinical Oral Surgery: A Comparison with Learning Styles

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Omar, Esam

2017-01-01

Purpose: Dental extraction is a routine part of clinical dental practice. For this reason, understanding the way how students’ extraction knowledge and skills development are important. Problem Statement and Objectives: To date, there is no accredited statement about the most effective method for the teaching of exodontia to dental students. Students have different abilities and preferences regarding how they learn and process information. This is defined as learning style. In this study, the effectiveness of active learning in the teaching of preclinical oral surgery was examined. The personality type of the groups involved in this study was determined, and the possible effect of personality type on learning style was investigated. Method: This study was undertaken over five years from 2011 to 2015. The sample consisted of 115 students and eight staff members. Questionnaires were submitted by 68 students and all eight staff members involved. Three measures were used in the study: The Index of Learning Styles (Felder and Soloman, 1991), the Myers-Briggs Type Indicator (MBTI), and the styles of learning typology (Grasha and Hruska-Riechmann). Results and Discussion: Findings indicated that demonstration and minimal clinical exposure give students personal validation. Frequent feedback on their work is strongly indicated to build the cognitive, psychomotor, and interpersonal skills needed from preclinical oral surgery courses. Conclusion: Small group cooperative active learning in the form of demonstration and minimal clinical exposure that gives frequent feedback and students’ personal validation on their work is strongly indicated to build the skills needed for preclinical oral surgery courses. PMID:28357004

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

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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.

Secondhand Smoke Exposure and Preclinical Markers of Cardiovascular Risk in Toddlers.

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Groner, Judith A; Huang, Hong; Joshi, Mandar S; Eastman, Nicholas; Nicholson, Lisa; Bauer, John Anthony

2017-10-01

To investigate relationships between secondhand smoke exposure in young children and several preclinical markers of cardiovascular risk that have been established as relevant to adult populations. There were 139 children, 2-5 years of age, enrolled in a cross-sectional study. Secondhand smoke exposure was objectively determined by hair nicotine level; a comprehensive panel of clinical markers (morning blood pressure, fasting glucose and insulin, lipid profiles, inflammation) and research markers (markers of oxidation, endothelial stress, and endothelial repair) of cardiovascular risk status were assessed. Univariate and multivariate linear regression were used to evaluate relationships between secondhand smoke exposure and cardiovascular risk markers. Hair nicotine levels were correlated directly with blood pressure and serum C-reactive protein, and inversely correlated with serum high-density lipoprotein cholesterol and endothelial cell progenitor cell prevalence. In multivariate analyses, these relationships remained when controlled for age, sex, body mass index z-score, maternal education, and method of payment. Additionally, in multivariate analyses, hair nicotine level was significantly negatively correlated with total antioxidant capacity. These results support the view that secondhand smoke exposure in the very young has a detectable relationship with several markers of cardiovascular risk, long before the emergence of clinical disease. Further studies to define mechanisms and strategies to prevent and mitigate these risks early in life are warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

Theory of mind and empathy in preclinical and clinical Huntington's disease.

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Adjeroud, Najia; Besnard, Jérémy; El Massioui, Nicole; Verny, Christophe; Prudean, Adriana; Scherer, Clarisse; Gohier, Bénédicte; Bonneau, Dominique; Allain, Philippe

2016-01-01

We investigated cognitive and affective Theory of Mind (ToM) and empathy in patients with premanifest and manifest Huntington's disease (HD). The relationship between ToM performance and executive skills was also examined. Sixteen preclinical and 23 clinical HD patients, and 39 healthy subjects divided into 2 control groups were given a French adaptation of the Yoni test (Shamay-Tsoory, S.G., Aharon-Peretz, J. (2007). Dissociable prefrontal networks for cognitive and affective theory of mind: a lesion study. Neuropsychologia, 45(3), 3054-67) that examines first- and second-order cognitive and affective ToM processing in separate conditions with a physical control condition. Participants were also given questionnaires of empathy and cognitive tests which mainly assessed executive functions (inhibition and mental flexibility). Clinical HD patients made significantly more errors than their controls in the first- and second-order cognitive and affective ToM conditions of the Yoni task, but exhibited no empathy deficits. However, there was no evidence that ToM impairment was related to cognitive deficits in these patients. Preclinical HD patients were unimpaired in ToM tasks and empathy measures compared with their controls. Our results are consistent with the idea that impaired affective and cognitive mentalizing emerges with the clinical manifestation of HD, but is not necessarily part of the preclinical stage. Furthermore, these impairments appear independent of executive dysfunction and empathy. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Evaluating the short-term effects of a communication skills program for preclinical medical students.

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Lee, Young-Mee; Lee, Young Hee

2014-09-01

Regardless of the growing importance of communication skills as a core clinical competence, few studies have determined the effects of communication skills courses in undergraduate medical curricula in Asian medical schools. The purpose of this study was to examine the effectiveness of a communication skills program for preclinical medical students. A communication skills course was provided to 111 second-year medical students in a medical college in Korea. Students' self-assessed competency of communication skills was evaluated by a questionnaire survey. To examine the improvement in observed communication skills, the students' encounters with standardized patients (SPs) were assessed at the first session and at the final course assessment. A structured checklist, consisting of 25 communication skills items, was used for the assessment. Students' self-assessed competency of communication skills increased significantly after completion of the course (pcommunication skills scores also improved significantly at the end of the course; the mean scores of the first SPs encounters was 49.6 (standard deviation [SD], 11.1), and those of cases A and B at the final assessment were 61.5 (SD, 8.4) and 69.6 (SD, 7.8), respectively (F61=269.54, pcommunication skills course was beneficial in developing and improving communication skills competency in preclinical medical students. Further studies should be followed to examine whether the acquisition of communication skills during preclinical studies can be sustained into clerkship and actual practice.

Preclinical Magnetic Resonance Fingerprinting (MRF) at 7 T: Effective Quantitative Imaging for Rodent Disease Models

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Gao, Ying; Chen, Yong; Ma, Dan; Jiang, Yun; Herrmann, Kelsey A.; Vincent, Jason A.; Dell, Katherine M.; Drumm, Mitchell L.; Brady-Kalnay, Susann M.; Griswold, Mark A.; Flask, Chris A.; Lu, Lan

2015-01-01

High field, preclinical magnetic resonance imaging (MRI) scanners are now commonly used to quantitatively assess disease status and efficacy of novel therapies in a wide variety of rodent models. Unfortunately, conventional MRI methods are highly susceptible to respiratory and cardiac motion artifacts resulting in potentially inaccurate and misleading data. We have developed an initial preclinical, 7.0 T MRI implementation of the highly novel Magnetic Resonance Fingerprinting (MRF) methodology that has been previously described for clinical imaging applications. The MRF technology combines a priori variation in the MRI acquisition parameters with dictionary-based matching of acquired signal evolution profiles to simultaneously generate quantitative maps of T1 and T2 relaxation times and proton density. This preclinical MRF acquisition was constructed from a Fast Imaging with Steady-state Free Precession (FISP) MRI pulse sequence to acquire 600 MRF images with both evolving T1 and T2 weighting in approximately 30 minutes. This initial high field preclinical MRF investigation demonstrated reproducible and differentiated estimates of in vitro phantoms with different relaxation times. In vivo preclinical MRF results in mouse kidneys and brain tumor models demonstrated an inherent resistance to respiratory motion artifacts as well as sensitivity to known pathology. These results suggest that MRF methodology may offer the opportunity for quantification of numerous MRI parameters for a wide variety of preclinical imaging applications. PMID:25639694

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

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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.

Does posterior cingulate hypometabolism result from disconnection or local pathology across preclinical and clinical stages of Alzheimer's disease?

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Teipel, Stefan [University of Rostock, Department of Psychosomatic Medicine, Rostock (Germany); DZNE, German Center for Neurodegenerative Diseases, Rostock (Germany); Alzheimer' s Disease Neuroimaging Initiative (United States); Grothe, Michel J. [DZNE, German Center for Neurodegenerative Diseases, Rostock (Germany); Alzheimer' s Disease Neuroimaging Initiative (United States)

2016-03-15

Posterior cingulate cortex (PCC) hypometabolism as measured by FDG PET is an indicator of Alzheimer's disease (AD) in prodromal stages, such as in mild cognitive impairment (MCI), and has been found to be closely associated with hippocampus atrophy in AD dementia.We studied the effects of local and remote atrophy and of local amyloid load on the PCC metabolic signal in patients with different preclinical and clinical stages of AD. We determined the volume of the hippocampus and PCC grey matter based on volumetric MRI scans, PCC amyloid load based on AV45 PET, and PCC metabolism based on FDG PET in 667 subjects participating in the Alzheimer's Disease Neuroimaging Initiative spanning the range from cognitively normal ageing through prodromal AD to AD dementia. In cognitively normal individuals and those with early MCI, PCC hypometabolism was exclusively associated with hippocampus atrophy, whereas in subjects with late MCI it was associated with both local and remote effects of atrophy as well as local amyloid load. In subjects with AD dementia, PCC hypometabolism was exclusively related to local atrophy. Our findings suggest that the effects of remote pathology on PCC hypometabolism decrease and the effects of local pathology increase from preclinical to clinical stages of AD, consistent with a progressive disconnection of the PCC from downstream cortical and subcortical brain regions. (orig.)

Does posterior cingulate hypometabolism result from disconnection or local pathology across preclinical and clinical stages of Alzheimer's disease?

International Nuclear Information System (INIS)

Teipel, Stefan; Grothe, Michel J.

2016-01-01

Posterior cingulate cortex (PCC) hypometabolism as measured by FDG PET is an indicator of Alzheimer's disease (AD) in prodromal stages, such as in mild cognitive impairment (MCI), and has been found to be closely associated with hippocampus atrophy in AD dementia.We studied the effects of local and remote atrophy and of local amyloid load on the PCC metabolic signal in patients with different preclinical and clinical stages of AD. We determined the volume of the hippocampus and PCC grey matter based on volumetric MRI scans, PCC amyloid load based on AV45 PET, and PCC metabolism based on FDG PET in 667 subjects participating in the Alzheimer's Disease Neuroimaging Initiative spanning the range from cognitively normal ageing through prodromal AD to AD dementia. In cognitively normal individuals and those with early MCI, PCC hypometabolism was exclusively associated with hippocampus atrophy, whereas in subjects with late MCI it was associated with both local and remote effects of atrophy as well as local amyloid load. In subjects with AD dementia, PCC hypometabolism was exclusively related to local atrophy. Our findings suggest that the effects of remote pathology on PCC hypometabolism decrease and the effects of local pathology increase from preclinical to clinical stages of AD, consistent with a progressive disconnection of the PCC from downstream cortical and subcortical brain regions. (orig.)

Learning style preferences among pre-clinical medical students

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Aye Aye Mon

2014-02-01

Full Text Available Generally, different students employ different learning styles dur-ing their studies and medical students are exposed to diverse methods of teaching. Therefore, understanding students’ learning style preference is an important consideration for a high quality and effective teaching and learning process.The aim of the study was to study the variation of learning styles among pre-clinical medical students of SEGi University, Malaysia. A cross-sectional study was performed by using VARK (Visual, Audio, Reading and Kinaesthetic questionnaire version 7.2 to assess the learning style preference of 98 (n=98 pre-clinical medical students in SEGi University. The questionnaire consists of 16 items which identify four different learning styles: visual, aural, reading/writing and kin-esthetic. Descriptive statistics were used to identify the learning styles of students. 61 students preferred multimodal as their learning style, out of which 43 (70% of them were female stu-dents and 18 (30% were male students. 37 students preferred unimodal as their learning style out of which 22 (59% of them were female students and 15 (41% were male students. In addi-tion, female students had more diverse preferences than male students by having 10 out of the other 11 possible combinations in multimodal learning style of preference, whereas the male stu-dents only had 5 out of the 11 combinations. In this study, there was no significant gender difference in the percentages of males and female students who preferred unimodal and multimodal styles of information presentation (P= 0.263; α=0.05. To con-clude, the majority of students of both genders had chosen quad-modal as their learning style preference. The results of this study can provide useful information for improving the quality of the teaching and learning experiences of students.

A cost-effective simulation curriculum for preclinical endodontics.

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Pileggi, Roberta; Glickman, Gerald N

2004-02-01

A challenge in contemporary dental education is to achieve a smooth transition from preclinical teaching environments to patient-care clinics in a cost-effective manner. The preclinical endodontic courses at The University of Texas, Dental Branch at Houston provide a unique learning environment that enables the student to perform endodontic treatment on extracted teeth in a typodont, and be involved in diagnosis and treatment-planning discussions. The specially designed stone typodont used has built-in radiographic capability, and is mounted at each chair in the clinic. During each preclinical session, students are assigned clinical cubicles and proper aseptic protocol is followed. Students are required to wear gloves, masks and eyewear, and place a rubber dam during treatment. Written self-assessment evaluations based upon prescribed criteria are utilised; feedback is given by faculty composed of both full-time endodontists and graduate students who periodically rotate and are calibrated on a regular basis. In the lecture phase, clinical case scenarios are presented to reinforce concepts of diagnosis and emergency care and to help integrate endodontics with other disciplines; a Socratic-like teaching style is established by the faculty facilitator to create an environment for developing critical-thinking and problem-solving skills. The overall feedback from graduating students has been very positive. Advantages of this format are an easier transition to patient management, a more keen interest in specialsation and a perceived increase in levels of confidence.

Optimised and rapid pre-clinical screening in the SOD1(G93A transgenic mouse model of amyotrophic lateral sclerosis (ALS.

Directory of Open Access Journals (Sweden)

Richard J Mead

Full Text Available The human SOD1(G93A transgenic mouse has been used extensively since its development in 1994 as a model for amyotrophic lateral sclerosis (ALS. In that time, a great many insights into the toxicity of mutant SOD1 have been gained using this and other mutant SOD transgenic mouse models. They all demonstrate a selective toxicity towards motor neurons and in some cases features of the pathology seen in the human disease. These models have two major drawbacks. Firstly the generation of robust preclinical data in these models has been highlighted as an area for concern. Secondly, the amount of time required for a single preclinical experiment in these models (3-4 months is a hurdle to the development of new therapies. We have developed an inbred C57BL/6 mouse line from the original mixed background (SJLxC57BL/6 SOD1(G93A transgenic line and show here that the disease course is remarkably consistent and much less prone to background noise, enabling reduced numbers of mice for testing of therapeutics. Secondly we have identified very early readouts showing a large decline in motor function compared to normal mice. This loss of motor function has allowed us to develop an early, sensitive and rapid screening protocol for the initial phases of denervation of muscle fibers, observed in this model. We describe multiple, quantitative readouts of motor function that can be used to interrogate this early mechanism. Such an approach will increase throughput for reduced costs, whilst reducing the severity of the experimental procedures involved.

Early-onset behavioral and neurochemical deficits in the genetic mouse model of phenylketonuria.

Science.gov (United States)

Fiori, Elena; Oddi, Diego; Ventura, Rossella; Colamartino, Marco; Valzania, Alessandro; D'Amato, Francesca Romana; Bruinenberg, Vibeke; van der Zee, Eddy; Puglisi-Allegra, Stefano; Pascucci, Tiziana

2017-01-01

Phenylketonuria (PKU) is one of the most common human inborn errors of metabolism, caused by phenylalanine hydroxylase deficiency, leading to high phenylalanine and low tyrosine levels in blood and brain causing profound cognitive disability, if untreated. Since 1960, population is screened for hyperphenylalaninemia shortly after birth and submitted to early treatment in order to prevent the major manifestations of the disease. However, the dietetic regimen (phenylalanine free diet) is difficult to maintain, and despite the recommendation to a strict and lifelong compliance, up to 60% of adolescents partially or totally abandons the treatment. The development and the study of new treatments continue to be sought, taking advantage of preclinical models, the most used of which is the PAHenu2 (BTBR ENU2), the genetic murine model of PKU. To date, adult behavioral and neurochemical alterations have been mainly investigated in ENU2 mice, whereas there are no clear indications about the onset of these deficiencies. Here we investigated and report, for the first time, a comprehensive behavioral and neurochemical assay of the developing ENU2 mice. Overall, our findings demonstrate that ENU2 mice are significantly smaller than WT until pnd 24, present a significant delay in the acquisition of tested developmental reflexes, impaired communicative, motor and social skills, and have early reduced biogenic amine levels in several brain areas. Our results extend the understanding of behavioral and cerebral abnormalities in PKU mice, providing instruments to an early preclinical evaluation of the effects of new treatments.

Spatial reversal learning in preclinical scrapie-inoculated mice.

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Lysons, A M; Woollard, S J

1996-04-10

Acquisition and reversal of a two-choice spatial discrimination were tested in scrapie-inoculated mice. Both acquisition and reversal were normal in mice tested 138 and 103 days prior to the onset of clinical symptoms. At 65 days before onset of clinical symptoms, scrapie-inoculated mice required more trails to criterion in reversal learning, but this effect was not significant in a second experiment (68 days preclinical) and was transient: no effect was seen 33 days before symptoms. However, the course of reversal learning was abnormal in all three late preclinical groups (68, 65 and 33 days before symptoms). Reversal learning in these three groups was characterized by a rapid extinction of the original discrimination, followed by a period, absent in controls, during which performance showed no further improvement. This effect corresponds in time of onset to the appearance of characteristic neuropathological features.

Preclinical antivenom-efficacy testing reveals potentially disturbing deficiencies of snakebite treatment capability in East Africa.

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Robert A Harrison

2017-10-01

Full Text Available Antivenom is the treatment of choice for snakebite, which annually kills an estimated 32,000 people in sub-Saharan Africa and leaves approximately 100,000 survivors with permanent physical disabilities that exert a considerable socioeconomic burden. Over the past two decades, the high costs of the most polyspecifically-effective antivenoms have sequentially reduced demand, commercial manufacturing incentives and production volumes that have combined to create a continent-wide vacuum of effective snakebite therapy. This was quickly filled with new, less expensive antivenoms, many of which are of untested efficacy. Some of these successfully marketed antivenoms for Africa are inappropriately manufactured with venoms from non-African snakes and are dangerously ineffective. The uncertain efficacy of available antivenoms exacerbates the complexity of designing intervention measures to reduce the burden of snakebite in sub-Saharan Africa. The objective of this study was to preclinically determine the ability of antivenoms available in Kenya to neutralise the lethal effects of venoms from the most medically important snakes in East Africa.We collected venom samples from the most medically important snakes in East Africa and determined their toxicity in a mouse model. Using a 'gold standard' comparison protocol, we preclinically tested the comparative venom-neutralising efficacy of four antivenoms available in Kenya with two antivenoms of clinically-proven efficacy. To explain the variant efficacies of these antivenoms we tested the IgG-venom binding characteristics of each antivenom using in vitro IgG titre, avidity and venom-protein specificity assays. We also measured the IgG concentration of each antivenom.None of the six antivenoms are preclinically effective, at the doses tested, against all of the most medically important snakes of the region. The very limited snake polyspecific efficacy of two locally available antivenoms is of concern. In vitro

The prevalence and consequences of burnout on a group of preclinical dental students.

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Atalayin, Cigdem; Balkis, Murat; Tezel, Huseyin; Onal, Banu; Kayrak, Gul

2015-01-01

The aim of this study is to investigate the prevalence of burnout among a group of Turkish preclinical dental students, to compare the level of burnout and to determine the consequences in structural equation model. Preclinical dental students (n = 329, 50.5% of females and 49.5% of males) aged between 18 and 24 took part in the study. Maslach burnout inventory student version, academic satisfaction scale, and personal information sheet were used to gather data. Pearson correlation analyses, t-test, and one-way ANOVA were used for statistical analysis. The proposed theoretical model was tested via observed variable path analysis using maximum likelihood parameter estimation with AMOS 7.0. About 22.3% of students had high level of emotional exhaustion, 16.7% of students had high level of cynicism, and 17.9% of students suffered from high level of reduced academic efficacy. While the students attending the first grade reported higher level of reduced academic efficacy, the students in the third grade reported higher level of emotional exhaustion. Academic workload played an important role in the development of burnout. As consequences of burnout, students with high levels of burnout intended to change their current major and did not to plan to continue to postgraduate education. Students with high level of burnout reported less level of academic satisfaction and academic achievement. Creating awareness on the burnout of dental students from the preclinical period may be useful for prevention and more compatible dental education environment.

Pre-clinical evaluation of extracts and essential oils from betel-like ...

African Journals Online (AJOL)

The extracts and oils were preclinically studied based on cyto - and genotoxicity using microculture tetrazolium (MTT) and comet assays. Results: The crude extracts showed an IC50 in leukocytes and HeLa cells of 58.59 -97.31 mg/ml and 34.91-101.79 mg/ml, the LD50 is higher than 5000 mg/kg. With lower values than the ...

Appropriate experimental approaches for predicting abuse potential and addictive qualities in preclinical drug discovery.

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Mead, Andy N

2014-11-01

Drug abuse is an increasing social and public health issue, putting the onus on drug developers and regulatory agencies to ensure that the abuse potential of novel drugs is adequately assessed prior to product launch. This review summarizes the core preclinical data that frequently contribute to building an understanding of abuse potential for a new molecular entity, in addition to highlighting models that can provide increased resolution regarding the level of risk. Second, an important distinction between abuse potential and addiction potential is drawn, with comments on how preclinical models can inform on each. While the currently adopted preclinical models possess strong predictive validity, there are areas for future refinement and research. These areas include a more refined use of self-administration models to assess relative reinforcement; and the need for open innovation in pursuing improvements. There is also the need for careful scientifically driven application of models rather than a standardization of methodologies, and the need to explore the opportunities that may exist for enhancing the value of physical dependence and withdrawal studies by focusing on withdrawal-induced drug seeking, rather than broad symptomology.

'Muscle-sparing' statins: preclinical profiles and future clinical use.

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Pfefferkorn, Jeffrey A

2009-03-01

Coronary heart disease (CHD) is a leading cause of death in the US, and hypercholesterolemia is a key risk factor for this disease. The current standard of care for treating hypercholesterolemia is the use of HMG-CoA reductase inhibitors, also known as statins, which block the rate-limiting step of cholesterol biosynthesis. In widespread clinical use, statins have proven safe and effective for both primary prevention of CHD and secondary prevention of coronary events. Results from several recent clinical trials have demonstrated that increasingly aggressive cholesterol-lowering therapy might offer additional protection against CHD compared with less aggressive treatment standards. While higher doses of current statin therapies are capable of achieving these more aggressive treatment goals, in certain cases statin-induced myalgia, the muscle pain or weakness that sometimes accompanies high-dose statin therapy, limits patient compliance with a treatment regimen. To address this limitation, efforts have been undertaken to develop highly hepatoselective statins that are capable of delivering best-in-class efficacy with minimized risk of dose-limiting myalgia. In this review, the preclinical and early clinical data for these next generation statins are discussed.

Preclinical evaluation of human T lymphocytes in RAG2-/-γc-/- mice

NARCIS (Netherlands)

Rijn, R.S. van

2006-01-01

This thesis describes the development and application of a new model for the preclinical study of human T cells by transfer of huPBMCs into RAG2-/-γc-/- immunodeficient mice. The ultimate goal of treating patients with a malignancy is to eradicate the malignant cells, while keeping hold of damage to

Preclinical magnetic resonance imaging and systems biology in cancer research: current applications and challenges.

Science.gov (United States)

Albanese, Chris; Rodriguez, Olga C; VanMeter, John; Fricke, Stanley T; Rood, Brian R; Lee, YiChien; Wang, Sean S; Madhavan, Subha; Gusev, Yuriy; Petricoin, Emanuel F; Wang, Yue

2013-02-01

Biologically accurate mouse models of human cancer have become important tools for the study of human disease. The anatomical location of various target organs, such as brain, pancreas, and prostate, makes determination of disease status difficult. Imaging modalities, such as magnetic resonance imaging, can greatly enhance diagnosis, and longitudinal imaging of tumor progression is an important source of experimental data. Even in models where the tumors arise in areas that permit visual determination of tumorigenesis, longitudinal anatomical and functional imaging can enhance the scope of studies by facilitating the assessment of biological alterations, (such as changes in angiogenesis, metabolism, cellular invasion) as well as tissue perfusion and diffusion. One of the challenges in preclinical imaging is the development of infrastructural platforms required for integrating in vivo imaging and therapeutic response data with ex vivo pathological and molecular data using a more systems-based multiscale modeling approach. Further challenges exist in integrating these data for computational modeling to better understand the pathobiology of cancer and to better affect its cure. We review the current applications of preclinical imaging and discuss the implications of applying functional imaging to visualize cancer progression and treatment. Finally, we provide new data from an ongoing preclinical drug study demonstrating how multiscale modeling can lead to a more comprehensive understanding of cancer biology and therapy. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Preclinical diagnosis of Alzheimer's disease: Prevention or prediction?

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Ricardo Nitrini

Full Text Available Abstract The diagnosis of Alzheimer's disease (AD for cases with dementia may be too late to allow effective treatment. Criteria for diagnosis of preclinical AD suggested by the Alzheimer's Association include the use of molecular and structural biomarkers. Preclinical diagnosis will enable testing of new drugs and forms of treatment toward achieving successful preventive treatment. But what are the advantages for the individual? To know that someone who is cognitively normal is probably going to develop AD's dementia when there is no effective preventive treatment is definitely not good news. A research method whereby volunteers are assigned to receive treatment or placebo without knowing whether they are in the control or at-risk arm of a trial would overcome this potential problem. If these new criteria are used wisely they may represent a relevant milestone in the search for a definitive treatment for AD.

Preclinical studies for increasing radiation response of malignant brain tumours

International Nuclear Information System (INIS)

Kalia, Vijay K.; Kumari, Kalyani; Sai Shyam; George, Jennifer; Shobha, A.G.; Chandrasekhar Sagar, B.K.; Lal, Jagath

2013-01-01

Malignant gliomas are the most common among the CNS cancers. Standard treatment for these tumours - comprises of surgery, followed by Radiotherapy (RT). Combination of Temozolomide (TMZ) increases survival, but hematological toxicities are also increased as compared to RT alone. The median survival depends on grade and location of tumour, as well as the age of the patient. Grade IV gliomas (GSMs) are third leading cause of cancer induced death in the age group of 15 to 34 years. Therefore, it is important to carry out further preclinical studies to develop more effective treatment of malignant gliomas. The present studies were carried out on different established malignant glioma cell lines. (U373MG) as well as primary monolayer cultures derived from biopsies obtained from patients with malignant gliomas. Exponentially growing cells were exposed to TMZ, Lonidamine (LND) (in 0.1% DMSO), or 2-Deoxy-D-Glucose (2-DG, aqueous solution) - with or without 60 Co-Gamma-rays (1- 2 Gy). The drugs were removed 4 hours after irradiation and the cultures were processed further for different assays of damage. Short term (4 h) treatments with TMZ 20 μM, LND 100 μM or their combination; did not induce micronuclei formation in the unirradiated cultures of U373MG cells. However, radiation (2 Gy) induced micronuclei was significantly increased by drug treatments. In primary cultures from different tumours, TMZ (≤ 10 μM) or 2-DG (1 mM), or gamma-irradiation (1-2 Gy) induced micronuclei and/ or apoptosis. The effects, however, varied in different tumours. These data show that clinically achievable, very low concentrations of these drugs could induce cellular damage and death; and increase radiosensitivity of malignant gliomas. Therefore, adjuvants like Lonidamine and 2-DG, with non-overlapping toxicities, could optimize treatment of malignant gliomas, by reducing the side effects of radio-chemotherapy. (author)

77 FR 71194 - Draft Guidance for Industry: Preclinical Assessment of Investigational Cellular and Gene Therapy...

Science.gov (United States)

2012-11-29

...] Draft Guidance for Industry: Preclinical Assessment of Investigational Cellular and Gene Therapy... Industry: Preclinical Assessment of Investigational Cellular and Gene Therapy Products,'' dated November... Evaluation (CBER), Office of Cellular, Tissue, and Gene Therapies (OCTGT). The product areas covered by this...

Two-Dimensional High Definition Versus Three-Dimensional Endoscopy in Endonasal Skull Base Surgery: A Comparative Preclinical Study.

Science.gov (United States)

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.

Stem Cells for Cartilage Repair: Preclinical Studies and Insights in Translational Animal Models and Outcome Measures

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Lo Monaco, Melissa; Merckx, Greet; Ratajczak, Jessica; Gervois, Pascal; Hilkens, Petra; Clegg, Peter; Bronckaers, Annelies; Vandeweerd, Jean-Michel; Lambrichts, Ivo

2018-01-01

Due to the restricted intrinsic capacity of resident chondrocytes to regenerate the lost cartilage postinjury, stem cell-based therapies have been proposed as a novel therapeutic approach for cartilage repair. Moreover, stem cell-based therapies using mesenchymal stem cells (MSCs) or induced pluripotent stem cells (iPSCs) have been used successfully in preclinical and clinical settings. Despite these promising reports, the exact mechanisms underlying stem cell-mediated cartilage repair remain...

Behavioral phenotyping of Parkin-deficient mice: looking for early preclinical features of Parkinson's disease.

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Daniel Rial

Full Text Available There is considerable evidence showing that the neurodegenerative processes that lead to sporadic Parkinson's disease (PD begin many years before the appearance of the characteristic motor symptoms. Neuropsychiatric, sensorial and cognitive deficits are recognized as early non-motor manifestations of PD, and are not attenuated by the current anti-parkinsonian therapy. Although loss-of-function mutations in the parkin gene cause early-onset familial PD, Parkin-deficient mice do not display spontaneous degeneration of the nigrostriatal pathway or enhanced vulnerability to dopaminergic neurotoxins such as 6-OHDA and MPTP. Here, we employed adult homozygous C57BL/6 mice with parkin gene deletion on exon 3 (parkin-/- to further investigate the relevance of Parkin in the regulation of non-motor features, namely olfactory, emotional, cognitive and hippocampal synaptic plasticity. Parkin-/- mice displayed normal performance on behavioral tests evaluating olfaction (olfactory discrimination, anxiety (elevated plus-maze, depressive-like behavior (forced swimming and tail suspension and motor function (rotarod, grasping strength and pole. However, parkin-/- mice displayed a poor performance in the open field habituation, object location and modified Y-maze tasks suggestive of procedural and short-term spatial memory deficits. These behavioral impairments were accompanied by impaired hippocampal long-term potentiation (LTP. These findings indicate that the genetic deletion of parkin causes deficiencies in hippocampal synaptic plasticity, resulting in memory deficits with no major olfactory, emotional or motor impairments. Therefore, parkin-/- mice may represent a promising animal model to study the early stages of PD and for testing new therapeutic strategies to restore learning and memory and synaptic plasticity impairments in PD.

Preclinical efficacy and safety of herbal formulation for management ...

African Journals Online (AJOL)

Preclinical efficacy and safety of herbal formulation for management of wounds. ... The effects of the treatments on rate of wound closure, epithelialisation time ... inflammation and better tissue remodeling for rats treated with herbal product.

The prevalence and correlations of medical student burnout in the pre-clinical years: a cross-sectional study.

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Mazurkiewicz, Rebecca; Korenstein, Deborah; Fallar, Robert; Ripp, Jonathan

2012-01-01

Burnout is a psychological syndrome of emotional exhaustion, depersonalization, and impaired personal accomplishment induced by repeated workplace stressors. Current research suggests that physician burnout may have its origins in medical school. The consequences of medical student burnout include both personal and professional distress, loss of empathy, and poor health. We hypothesized that burnout occurs prior to the initiation of the clinical years of medical education. This was a cross-sectional survey administered to third-year medical students at the Mount Sinai School of Medicine (MSSM) in New York, New York (a traditional-style medical school with a marked division between pre-clinical and clinical training occurring at the beginning of the third year). Survey included an instrument used to measure job burnout, a sleep deprivation screen, and questions related to demographic information, current rotation, psychiatric history, time spent working/studying, participation in extracurricular activities, social support network, autonomy and isolation. Of the 86 medical students who participated, 71% met criteria for burnout. Burnt out students were significantly more likely to suffer from sleep deprivation (p = 0.0359). They were also more likely to disagree with the following statements: "I have control over my daily schedule" (p = 0.0286) and "I am confident that I will have the knowledge and skills necessary to become an intern when I graduate" (p = 0.0263). Our findings show that burnout is present at the beginning of the third year of medical school, prior to the initiation of the clinical years of medical training. Medical student burnout is quite common, and early efforts should be made to empower medical students to both build the knowledge and skills necessary to become capable physicians, as well as withstand the emotional, mental, and physical challenges inherent to medical school.

How does preclinical laboratory training impact physical examination skills during the first clinical year? A retrospective analysis of routinely collected objective structured clinical examination scores among the first two matriculating classes of a reformed curriculum in one Polish medical school.

Science.gov (United States)

Świerszcz, Jolanta; Stalmach-Przygoda, Agata; Kuźma, Marcin; Jabłoński, Konrad; Cegielny, Tomasz; Skrzypek, Agnieszka; Wieczorek-Surdacka, Ewa; Kruszelnicka, Olga; Chmura, Kaja; Chyrchel, Bernadeta; Surdacki, Andrzej; Nowakowski, Michał

2017-09-01

As a result of a curriculum reform launched in 2012 at our institution, preclinical training was shortened to 2 years instead of the traditional 3 years, creating additional incentives to optimise teaching methods. In accordance with the new curriculum, a semester-long preclinical module of clinical skills (CS) laboratory training takes place in the second year of study, while an introductory clinical course (ie, brief introductory clerkships) is scheduled for the Fall semester of the third year. Objective structured clinical examinations (OSCEs) are carried out at the conclusion of both the preclinical module and the introductory clinical course. Our aim was to compare the scores at physical examination stations between the first and second matriculating classes of a newly reformed curriculum on preclinical second-year OSCEs and early clinical third-year OSCEs. Analysis of routinely collected data. One Polish medical school. Complete OSCE records for 462 second-year students and 445 third-year students. OSCE scores by matriculation year. In comparison to the first class of the newly reformed curriculum, significantly higher (ie, better) OSCE scores were observed for those students who matriculated in 2013, a year after implementing the reformed curriculum. This finding was consistent for both second-year and third-year cohorts. Additionally, the magnitude of the improvement in median third-year OSCE scores was proportional to the corresponding advancement in preceding second-year preclinical OSCE scores for each of two different sets of physical examination tasks. In contrast, no significant difference was noted between the academic years in the ability to interpret laboratory data or ECG - tasks which had not been included in the second-year preclinical training. Our results suggest the importance of preclinical training in a CS laboratory to improve students' competence in physical examination at the completion of introductory clinical clerkships during

Content and goals of preclinical prosthodontic programs at german-language dental schools.

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Hey, Jeremias; Stimmelmayr, Michael; Hirsch, Christian; Beuer, Florian

2014-04-01

The Association for Dental Education in Europe (ADEE) makes recommendations regarding the skills graduates of European dental schools need to achieve and advises dental schools regarding necessary changes to be made to the curriculum. In 2010 to 2011, a survey was conducted in German-language dental schools to validate the curricula and goals of preclinical prosthodontic programs with regard to laboratory work. The survey was mailed to the course instructors of the preclinical programs at 37 dental schools. Of these, 35 schools returned the completed survey, resulting in a response rate of 95%. Bent wire, wax-up exercises, metal-ceramic single crowns, fixed dental prostheses, cast metal single crowns, temporary removable dental prostheses, and full dentures were part of the dental laboratory work at most schools; however, most instructors considered laboratory work as less important, and there were few similarities among the programs in this area. According to the instructors responsible for preclinical education, honing of fine motor skills, realistic self-assessment, and the ability to work independently were the main goals of the programs. The results of this survey show that with regard to laboratory work, there were more differences than similarities among preclinical prosthodontic programs at German-language dental schools, contrary to the recommendations of the ADEE. These findings should be taken into account when program reforms are planned. © 2013 by the American College of Prosthodontists.

Preclinical studies on [{sup 11}C]MPDX for mapping adenosine A{sub 1} receptors by positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Ishiwata, Kiichi; Kimura, Yuichi; Oda, Keiichi; Kawamura, Kazunori; Ishii, Kenji; Senda, Michio [Tokyo Metropolitan Inst. of Gerontology (Japan). Positron Medical Center; Nariai, Tadashi; Wakabayashi, Shinichi [Tokyo Medical and Dental Univ. (Japan). School of Medicine; Shimada, Junichi [Kyowa Hakko Kogyo Co. Ltd., Tokyo (Japan). Pharmaceutical Research Inst.

2002-09-01

In previous in vivo studies with mice, rats and cats, we have demonstrated that [{sup 11}C]MPDX ([1-methyl-{sup 11}C]8-dicyclopropylmethyl-1-methyl-3-propylxanthine) is a potential radioligand for mapping adenosine A{sub 1} receptors of the brain by positron emission tomography (PET). In the present study, we performed a preclinical study. The radiation absorbed-dose by [{sup 11}C]MPDX in humans estimated from the tissue distribution in mice was low enough for clinical use, and the acute toxicity and mutagenicity of MPDX were not found. The monkey brain was clearly visualized by PET with [{sup 11}C]MPDX. We have concluded that [{sup 11}C]MPDX is suitable for mapping adenosine A{sub 1} receptors in the human brain by PET. (author)

Dementia, preclinical studies in neurodegeneration and its potential for translational medicine in SouthAmerica

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Gloria Patricia Cardona Gomez

2016-12-01

Full Text Available Latin-American people with dementia will increase in a 368% in 2050, higher than USA and Europe. In addition, to sporadic dementia type Alzheimer and vascular dementia progression after Cerebrovascular disease, the statistics are increased in Colombia by specific populations affected with pure neurodegenerative and vascular dementias like autosomical dominant familial Alzheimer´s disease and CADASIL. In spite of the enormous human and economical effort and investment, neither sporadic nor genetic kinds of dementia progression have been prevented or blocked yet. Currently, 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, 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 some of them identified by the blocking and prevention of neurodegeneration. On the other side, the casuistic of pure dementias in the Latin-American region give an exceptional opportunity to understand the pathogenesis

METHODOLOGICAL APPROACHES TO EXPERT EVALUATION OF PRECLINICAL AND CLINICAL TRIALS OF HUMAN IMMUNOGLOBULIN PRODUCTS

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V. B. Ivanov

2017-01-01

Full Text Available The article considers the experience of Russian and leading foreign regulatory agencies in organisation and conduction of preclinical and clinical trials of human immunoglobulin products. The authors suggest a classification of human immunoglobulins and provide updated information on authorization of these products in Russia. The article summarizes methodological approaches, basic scientific principles and criteria relating to expert evaluation of preclinical and clinical trials of blood products. The authors further define the expert body’s requirements for data on preclinical and clinical trials of human normal immuniglobulins and human specific immunoglobulins for the prevention and/or treatment of infectious and non-infectious diseases which are submitted as part of applications for marketing authorization or marketing authorization variation. The article suggests programs of preclinical and clinical trials for human normal immunoglobulins and human specific immunoglobulins for the prevention and/or treatment of infectious and non-infectious diseases that are aligned with the Russian legislation and Eurasian Economic Union’s regulations on medicines circulation, and have been elaborated with respect to the guidelines of the European Medicines Agency.

Potential bias factors that affect the course evaluation of students in preclinical courses

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Su Jin Chae

2017-06-01

Full Text Available Purpose We aim to identify what potential bias factors affected students’ overall course evaluation, and to observe what factors should be considered in the curriculum evaluation system of medical schools. Methods This study analyzed students’ ratings of preclinical instructions at the Ajou University School of Medicine. The ratings of instructions involved 41 first-year and 45 second-year medical students. Results There was a statistically significant difference between years of study and ratings’ scoring. Learning difficulty, learning amount, student assessment, and teacher preparation from second-year students were significantly higher than first-year students (p<0.05. The analysis results revealed that student assessment was the predictor of ratings from first-year students, while teacher preparation was the predictor of ratings from second-year students. Conclusion We found significant interactions between year of study and the students’ rating results. We were able to confirm that satisfaction of instructions factors perceived by medical students were different for the characteristics of courses. Our results may be an important resource for evaluating preclinical curriculums.

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

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Paulo Henrique Rosado-de-Castro

2016-01-01

Full Text Available 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.

Prediction of practical performance in preclinical laboratory courses – the return of wire bending for admission of dental students in Hamburg

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Kothe, Christian

2014-05-01

Full Text Available [english] Although some recent studies concluded that dexterity is not a reliable predictor of performance in preclinical laboratory courses in dentistry, they could not disprove earlier findings which confirmed the worth of manual dexterity tests in dental admission. We developed a wire bending test (HAM-Man which was administered during dental freshmen’s first week in 2008, 2009, and 2010. The purpose of our study was to evaluate if the HAM-Man is a useful selection criterion additional to the high school grade point average (GPA in dental admission. Regression analysis revealed that GPA only accounted for a maximum of 9% of students’ performance in preclinical laboratory courses, in six out of eight models the explained variance was below 2%. The HAM-Man incrementally explained up to 20.5% of preclinical practical performance over GPA. In line with findings from earlier studies the HAM-Man test of manual dexterity showed satisfactory incremental validity. While GPA has a focus on cognitive abilities, the HAM-Man reflects learning of unfamiliar psychomotor skills, spatial relationships, and dental techniques needed in preclinical laboratory courses. The wire bending test HAM-Man is a valuable additional selection instrument for applicants of dental schools.

Cognitive reserve and lifestyle: moving towards preclinical Alzheimer’s disease

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Eider M Arenaza-Urquijo

2015-08-01

Full Text Available The large majority of neuroimaging studies in Alzheimer’s disease (AD patients have supported the idea that lifestyle factors may protect against the clinical manifestations of AD rather than influence AD neuropathological processes (the cognitive reserve hypothesis. This evidence argues in favor of the hypothesis that lifestyle factors act as moderators between AD pathology and cognition, i.e. through indirect compensatory mechanisms. In this review, we identify emerging evidence in cognitively normal older people that relate lifestyle factors to established AD neuroimaging biomarkers. While some of these investigations are in agreement with the compensatory view of cognitive reserve, other studies have revealed new clues on the neural mechanisms underlying beneficial effects of lifestyle factors on the brain. Specifically, they provide novel evidence suggesting direct effects of lifestyle factors on AD neuropathological processes. Here, we review current findings on the effects of lifestyle factors on AD neuroimaging biomarkers in cognitively normal older people. We propose a tentative theoretical model where lifestyle factors may act via direct neuroprotective and/or indirect compensatory pathways. Importantly, we suggest that neuroprotective mechanisms may have a major role during early stages and compensatory pathways in later stages of the disease. In the absence of an effective treatment for AD and considering the potential of lifestyle factors in AD prevention, understanding the neural mechanisms underlying lifestyle effects on the brain seems crucial. We hope to provide an integrative view that may help to better understand the complex effects of lifestyle factors on AD neuropathological processes, starting from the preclinical stage.

Efficacy and safety of regenerative cell therapy for pulmonary arterial hypertension in animal models: a preclinical systematic review protocol.

Science.gov (United States)

Suen, Colin M; Zhai, Alex; Lalu, Manoj M; Welsh, Christopher; Levac, Brendan M; Fergusson, Dean; McIntyre, Lauralyn; Stewart, Duncan J

2016-05-25

Pulmonary arterial hypertension (PAH) is a rare disease (15 cases per million) that is characterized by widespread loss of the pulmonary microcirculation and elevated pulmonary vascular resistance leading to pathological right ventricular remodeling and ultimately right heart failure. Regenerative cell therapies (i.e., therapies involving cells with stem or progenitor-like properties) could potentially restore the effective lung microcirculation and provide a curative therapy for PAH. Preclinical evidence suggests that regenerative cell therapy using endothelial progenitor cells or mesenchymal stem cells may be beneficial in the treatment of PAH. These findings have led to the completion of a small number of human clinical trials, albeit with modest effect compared to animal studies. The objective of this systematic review is to compare the efficacy and safety of regenerative cell therapies in preclinical models of PAH as well as assess study quality to inform future clinical studies. We will include preclinical studies of PAH in which a regenerative cell type was administered and outcomes compared to a disease control. The primary outcome will be pulmonary hemodynamics as assessed by measurement of right ventricular systolic pressure and/or mean pulmonary arterial pressure. Secondary outcomes will include mortality, survival, right ventricular remodeling, pulmonary vascular resistance, cardiac output, cardiac index, pulmonary acceleration time, tricuspid annular systolic excursion, and right ventricular wall thickness. Electronic searches of MEDLINE and EMBASE databases will be constructed and reviewed by the Peer Review of Electronic Search Strategies (PRESS) process. Search results will be screened independently in duplicate. Data from eligible studies will be extracted, pooled, and analyzed using random effects models. Risk of bias will be assessed using the SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE) risk of bias tool, and

Is lecture dead? A preliminary study of medical students' evaluation of teaching methods in the preclinical curriculum.

Science.gov (United States)

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.

Collaborating with Alexander Scriabine and the Miles Institute for Preclinical Pharmacology.

Science.gov (United States)

Janis, Ronald A

2015-11-15

This article represents a timely opportunity to express my affection, admiration and gratitude to Professor David Triggle. David was my Ph.D. advisor as well as a key consultant in the 1980s and early 1990s for research programs at Miles Institute for Preclinical Pharmacology in West Haven, CT, the U.S. research operation of Bayer AG, in the areas of Ca(2+) and K(+) channel ligands. The binding methodology developed in his laboratory was used to search for an endogenous ligand for L-type Ca(2+) channels. We did not find the substance that we were searching for, a genetically-determined, competitive inhibitor for the 1,4-dihydropyridine binding site, but instead isolated the endogenous ligand for the brain's own marijuana, anandamide. Devane, Mechoulam and coworkers first discovered that this compound was the endogenous ligand for delta-9-tetrahydrocannabinol, the active substance in cannabis. The endogenous endocannabinoid system is now the target of many exciting new approaches to drug discovery. Copyright © 2015 Elsevier Inc. All rights reserved.

Preclinical and clinical studies of photodynamic action on some pathogenic micro-organisms of the oral cavity

Science.gov (United States)

Ovchinnikov, Ilya S.; Tuchin, Valery V.; Ivanov, Krill I.; Titorenko, Vladimir A.

2001-10-01

The work is devoted to an analysis of pre-clinical and clinical experiments on photodynamic action of HeNe laser radiation in aggregate with a cation thiazinium dye Methylene Blue (MB) on a mix of pathogenic and conditionally pathogenic aerobic bacteria being activators of pyoinflammatory diseases of oral cavity. Concentration of photosensitizes at which there is no own bactericidal influence on dying microflora, and parameters of influence at which the efficiency of irradiated microflora defeat reaches 99% are determined.

Pre-clinical medical student experience in a pediatric pulmonary clinic

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Thomas G. Saba

2015-11-01

Full Text Available Objective: Our objective was to evaluate the educational value of introducing pre-clinical medical students to pediatric patients and their families in a subspecialty clinic setting. Methods: First- and second-year medical students at the University of Michigan seeking clinical experience outside of the classroom attended an outpatient pediatric pulmonary clinic. Evaluation of the experience consisted of pre- and post-clinic student surveys and post-clinic parent surveys with statements employing a four-point Likert scale as well as open-ended questions. Results: Twenty-eight first-year students, 6 second-year students, and 33 parents participated in the study. Post-clinic statement scores significantly increased for statements addressing empathic attitudes, confidence communicating with children and families, comfort in the clinical environment, and social awareness. Scores did not change for statements addressing motivation, a sense of team membership, or confidence with career goals. Students achieved their goals of gaining experience interacting with patients, learning about pulmonary diseases, and observing clinic workflow. Parents felt that they contributed to student education and were not inconvenienced. Conclusions: Students identified several educational benefits of exposure to a single pediatric pulmonary clinic. Patients and families were not inconvenienced by the participation of a student. Additional studies are warranted to further investigate the value of this model of pre-clinical medical student exposure to subspecialty pediatrics.

Preclinical Pharmacokinetic/Pharmacodynamic Modeling and Simulation in the Pharmaceutical Industry: An IQ Consortium Survey Examining the Current Landscape

OpenAIRE

Schuck, Edgar; Bohnert, Tonika; Chakravarty, Arijit; Damian-Iordache, Valeriu; Gibson, Christopher; Hsu, Cheng-Pang; Heimbach, Tycho; Krishnatry, Anu Shilpa; Liederer, Bianca M; Lin, Jing; Maurer, Tristan; Mettetal, Jerome T; Mudra, Daniel R; Nijsen, Marjoleen JMA; Raybon, Joseph

2015-01-01

The application of modeling and simulation techniques is increasingly common in preclinical stages of the drug discovery and development process. A survey focusing on preclinical pharmacokinetic/pharmacodynamics (PK/PD) analysis was conducted across pharmaceutical companies that are members of the International Consortium for Quality and Innovation in Pharmaceutical Development. Based on survey responses, ~68% of companies use preclinical PK/PD analysis in all therapeutic areas indicating its...

Rethinking the Food and Drug Administration's 2013 guidance on developing drugs for early-stage Alzheimer's disease.

Science.gov (United States)

Schneider, Lon S

2014-03-01

The February 2013 Food and Drug Administration (FDA) draft guidance for developing drugs for early-stage Alzheimer's disease (AD) creates certain challenges as they guide toward the use of one cognitive outcome to gain accelerated marketing approval for preclinical AD drugs, and a composite clinical scale - the Clinical Dementia Rating Scale in particular - for the primary outcome for prodromal AD clinical trials. In light of the developing knowledge regarding early stage diagnoses and clinical trials outcomes, we recommend that FDA describe its requirements for validating preclinical AD diagnoses for drug development purposes, maintain the principle for requiring coprimary outcomes, and encourage the advancement of outcomes for early stage AD trials. The principles for drug development for early stage AD should not differ from those for clinical AD, especially as the diagnoses of prodromal and early AD impinge on each other. The FDA should not recommend that a composite scale be used as a sole primary efficacy outcome to support a marketing claim unless it requires that the cognitive and functional components of such a scale are demonstrated to be individually meaningful. The current draft guidelines may inadvertently constrain efforts to better assess the clinical effects of new drugs and inhibit innovation in an area where evidence-based clinical research practices are still evolving. Copyright © 2014 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Image-guided drug delivery: preclinical applications and clinical translation

NARCIS (Netherlands)

Ojha, Tarun; Rizzo, Larissa; Storm, Gerrit; Kiessling, Fabian; Lammers, Twan Gerardus Gertudis Maria

2015-01-01

Image-guided drug delivery refers to the combination of drug targeting and imaging. Preclinically, image-guided drug delivery can be used for several different purposes, including for monitoring biodistribution, target site accumulation, off-target localization, drug release and drug efficacy.

Dual-energy computed tomography for the assessment of early treatment effects of regorafenib in a preclinical tumor model: comparison with dynamic contrast-enhanced CT and conventional contrast-enhanced single-energy CT

International Nuclear Information System (INIS)

Knobloch, Gesine; Hamm, Bernd; Jost, Gregor; Pietsch, Hubertus; Huppertz, Alexander

2014-01-01

The potential diagnostic value of dual-energy computed tomography (DE-CT) compared to dynamic contrast-enhanced CT (DCE-CT) and conventional contrast-enhanced CT (CE-CT) in the assessment of early regorafenib treatment effects was evaluated in a preclinical setting. A rat GS9L glioma model was examined with contrast-enhanced dynamic DE-CT measurements (80 kV/140 kV) for 4 min before and on days 1 and 4 after the start of daily regorafenib or placebo treatment. Tumour time-density curves (0-240 s, 80 kV), DE-CT (60 s) derived iodine maps and the DCE-CT (0-30 s, 80 kV) based parameters blood flow (BF), blood volume (BV) and permeability (PMB) were calculated and compared to conventional CE-CT (60 s, 80 kV). The regorafenib group showed a marked decrease in the tumour time-density curve, a significantly lower iodine concentration and a significantly lower PMB on day 1 and 4 compared to baseline, which was not observed for the placebo group. CE-CT showed a significant decrease in tumour density on day 4 but not on day 1. The DE-CT-derived iodine concentrations correlated with PMB and BV but not with BF. DE-CT allows early treatment monitoring, which correlates with DCE-CT. Superior performance was observed compared to single-energy CE-CT. circle Regorafenib treatment response was evaluated by CT in a rat tumour model. (orig.)

Dual-energy computed tomography for the assessment of early treatment effects of regorafenib in a preclinical tumor model: comparison with dynamic contrast-enhanced CT and conventional contrast-enhanced single-energy CT

Energy Technology Data Exchange (ETDEWEB)

Knobloch, Gesine; Hamm, Bernd [Charite - Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Jost, Gregor; Pietsch, Hubertus [Bayer Healthcare, MR and CT Contrast Media Research, Berlin (Germany); Huppertz, Alexander [Imaging Science Institute Charite - Siemens, Berlin (Germany)

2014-08-15

The potential diagnostic value of dual-energy computed tomography (DE-CT) compared to dynamic contrast-enhanced CT (DCE-CT) and conventional contrast-enhanced CT (CE-CT) in the assessment of early regorafenib treatment effects was evaluated in a preclinical setting. A rat GS9L glioma model was examined with contrast-enhanced dynamic DE-CT measurements (80 kV/140 kV) for 4 min before and on days 1 and 4 after the start of daily regorafenib or placebo treatment. Tumour time-density curves (0-240 s, 80 kV), DE-CT (60 s) derived iodine maps and the DCE-CT (0-30 s, 80 kV) based parameters blood flow (BF), blood volume (BV) and permeability (PMB) were calculated and compared to conventional CE-CT (60 s, 80 kV). The regorafenib group showed a marked decrease in the tumour time-density curve, a significantly lower iodine concentration and a significantly lower PMB on day 1 and 4 compared to baseline, which was not observed for the placebo group. CE-CT showed a significant decrease in tumour density on day 4 but not on day 1. The DE-CT-derived iodine concentrations correlated with PMB and BV but not with BF. DE-CT allows early treatment monitoring, which correlates with DCE-CT. Superior performance was observed compared to single-energy CE-CT. circle Regorafenib treatment response was evaluated by CT in a rat tumour model. (orig.)

Attitudes of Pre-Clinical and Clinical Medical Students to Psychiatry ...

African Journals Online (AJOL)

Attitudes of Pre-Clinical and Clinical Medical Students to Psychiatry. ... Nigerian Hospital Practice ... Abstract. Medical training provides an environment in which proper and professional attitudes towards psychiatric patients can be acquired.

Quantifying lead-time bias in risk factor studies of cancer through simulation.

Science.gov (United States)

Jansen, Rick J; Alexander, Bruce H; Anderson, Kristin E; Church, Timothy R

2013-11-01

Lead-time is inherent in early detection and creates bias in observational studies of screening efficacy, but its potential to bias effect estimates in risk factor studies is not always recognized. We describe a form of this bias that conventional analyses cannot address and develop a model to quantify it. Surveillance Epidemiology and End Results (SEER) data form the basis for estimates of age-specific preclinical incidence, and log-normal distributions describe the preclinical duration distribution. Simulations assume a joint null hypothesis of no effect of either the risk factor or screening on the preclinical incidence of cancer, and then quantify the bias as the risk-factor odds ratio (OR) from this null study. This bias can be used as a factor to adjust observed OR in the actual study. For this particular study design, as average preclinical duration increased, the bias in the total-physical activity OR monotonically increased from 1% to 22% above the null, but the smoking OR monotonically decreased from 1% above the null to 5% below the null. The finding of nontrivial bias in fixed risk-factor effect estimates demonstrates the importance of quantitatively evaluating it in susceptible studies. Copyright © 2013 Elsevier Inc. All rights reserved.

Biosafety preclinical trials of xenogenic, Allogeniec and autologous progenitor cells from fat tissue

OpenAIRE

Melikhova, Vs; Saburina, I.; Repin, V.; Novikova, N.; Murashev, A.; Orlov, A.

2008-01-01

Due to wide spread of new methods of regenerative medicine on basis of stem cells it has become increasingly necessary to establish standards of techniques using them. Preclinical trial of a new technology after receiving preliminary experiment results is a primary stage of its adoption. We carried out the experiments to assess biosafety of autogenous, allergenic and xenogeneic cultures of human and rat cells in models under standard preclinical experiments conditions used in a presentday pha...

Early dementia diagnosis and the risk of suicide and euthanasia.

Science.gov (United States)

Draper, Brian; Peisah, Carmelle; Snowdon, John; Brodaty, Henry

2010-01-01

Diagnosis of dementia is occurring earlier, and much research concerns the identification of predementia states and the hunt for biomarkers of Alzheimer's disease. Reports of suicidal behavior and requests for euthanasia in persons with dementia may be increasing. We performed a selective literature review of suicide risk in persons with dementia and the ethical issues associated with euthanasia in this population. In the absence of any effective treatments for Alzheimer's disease or other types of dementia, there is already evidence that persons with mild cognitive change and early dementia are at risk of suicidal behavior, often in the context of comorbid depression. The ensuing clinical, ethical, and legal dilemmas associated with physician-assisted suicide and euthanasia in the context of dementia are a subject of intense debate. By analogy, the preclinical and early diagnoses of Huntington's disease are associated with an increased risk of suicidal behavior. Thus there is the potential for a preclinical and early diagnosis of Alzheimer's disease (through biomarkers, neuroimaging, and clinical assessment) to result in increased suicide risk and requests for physician-assisted suicide. Although dementia specialists have long recognized the importance of a sensitive approach to conveying bad news to patients and families and the possibility of depressive reactions, suicidal behavior has not been regarded as a likely outcome. Such preconceptions will need to change, and protocols to monitor and manage suicide risk will need to be developed for this population. 2010 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Pre-clinical research in small animals using radiotherapy technology. A bidirectional translational approach

International Nuclear Information System (INIS)

Tillner, Falk; Buetof, Rebecca; Krause, Mechthild; Enghardt, Wolfgang; Helmholtz-Zentrum Dresden-Rossendorf, Dresden; Technische Univ. Dresden; Helmholtz-Zentrum Dresden-Rossendorf, Dresden

2014-01-01

For translational cancer research, pre-clinical in-vivo studies using small animals have become indispensable in bridging the gap between in-vitro cell experiments and clinical implementation. When setting up such small animal experiments, various biological, technical and methodical aspects have to be considered. In this work we present a comprehensive topical review based on relevant publications on irradiation techniques used for pre-clinical cancer research in mice and rats. Clinical radiotherapy treatment devices for the application of external beam radiotherapy and brachytherapy as well as dedicated research irradiation devices are feasible for small animal irradiation depending on the animal model and the experimental goals. In this work, appropriate solutions for the technological transfer of human radiation oncology to small animal radiation research are summarised. Additionally, important information concerning the experimental design is provided such that reliable and clinically relevant results can be attained.

A student-initiated and student-facilitated international health elective for preclinical medical students.

Science.gov (United States)

Vora, Nirali; Chang, Mina; Pandya, Hemang; Hasham, Aliya; Lazarus, Cathy

2010-02-15

Global health education is becoming more important for developing well-rounded physicians and may encourage students toward a career in primary care. Many medical schools, however, lack adequate and structured opportunities for students beginning the curriculum. Second-year medical students initiated, designed, and facilitated a pass-fail international health elective, providing a curricular framework for preclinical medical students wishing to gain exposure to the clinical and cultural practices of a developing country. All course participants (N=30) completed a post-travel questionnaire within one week of sharing their experiences. Screening reflection essays for common themes that fulfill university core competencies yielded specific global health learning outcomes, including analysis of health care determinants. Medical students successfully implemented a sustainable global health curriculum for preclinical student peers. Financial constraints, language, and organizational burdens limit student participation. In future, long-term studies should analyze career impact and benefits to the host country.

Pre-clinical research in small animals using radiotherapy technology. A bidirectional translational approach

Energy Technology Data Exchange (ETDEWEB)

Tillner, Falk; Buetof, Rebecca [Technische Univ. Dresden (Germany). OncoRay - National Center for Radiation Research in Oncology; Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Univ. Dresden (Germany). Dept. of Radiation Oncology; Thute, Prasad [Technische Univ. Dresden (Germany). OncoRay - National Center for Radiation Research in Oncology; Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Krause, Mechthild [Technische Univ. Dresden (Germany). OncoRay - National Center for Radiation Research in Oncology; Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Univ. Dresden (Germany). Dept. of Radiation Oncology; German Cancer Consortium (DKTK), Dresden (Germany); German Cancer Research Center (DKFZ), Heidelberg (Germany); Enghardt, Wolfgang [Technische Univ. Dresden (Germany). OncoRay - National Center for Radiation Research in Oncology; Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Univ. Dresden (Germany). Dept. of Radiation Oncology; Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany). Inst. of Radiooncology

2014-07-01

For translational cancer research, pre-clinical in-vivo studies using small animals have become indispensable in bridging the gap between in-vitro cell experiments and clinical implementation. When setting up such small animal experiments, various biological, technical and methodical aspects have to be considered. In this work we present a comprehensive topical review based on relevant publications on irradiation techniques used for pre-clinical cancer research in mice and rats. Clinical radiotherapy treatment devices for the application of external beam radiotherapy and brachytherapy as well as dedicated research irradiation devices are feasible for small animal irradiation depending on the animal model and the experimental goals. In this work, appropriate solutions for the technological transfer of human radiation oncology to small animal radiation research are summarised. Additionally, important information concerning the experimental design is provided such that reliable and clinically relevant results can be attained.

Using cross-species comparisons and a neurobiological framework to understand early social deprivation effects on behavioral development.

Science.gov (United States)

Brett, Zoë H; Humphreys, Kathryn L; Fleming, Alison S; Kraemer, Gary W; Drury, Stacy S

2015-05-01

Building upon the transactional model of brain development, we explore the impact of early maternal deprivation on neural development and plasticity in three neural systems: hyperactivity/impulsivity, executive function, and hypothalamic-pituitary-adrenal axis functioning across rodent, nonhuman primate, and human studies. Recognizing the complexity of early maternal-infant interactions, we limit our cross-species comparisons to data from rodent models of artificial rearing, nonhuman primate studies of peer rearing, and the relations between these two experimental approaches and human studies of children exposed to the early severe psychosocial deprivation associated with institutional care. In addition to discussing the strengths and limitations of these paradigms, we present the current state of research on the neurobiological impact of early maternal deprivation and the evidence of sensitive periods, noting methodological challenges. Integrating data across preclinical animal models and human studies, we speculate about the underlying biological mechanisms; the differential impact of deprivation due to temporal factors including onset, offset, and duration of the exposure; and the possibility and consequences of reopening of sensitive periods during adolescence.

Anesthetic neuroprotection: antecedents and an appraisal of preclinical and clinical data quality.

Science.gov (United States)

Ishida, Kazuyoshi; Berger, Miles; Nadler, Jacob; Warner, David S

2014-01-01

Anesthetics have been studied for nearly fifty years as potential neuroprotective compounds in both perioperative and resuscitation medicine. Although anesthetics present pharmacologic properties consistent with preservation of brain viability in the context of an ischemic insult, no anesthetic has been proven efficacious for neuroprotection in humans. After such effort, it could be concluded that anesthetics are simply not neuroprotective in humans. Moreover, pharmacologic neuroprotection with non-anesthetic drugs has also repeatedly failed to be demonstrated in human acute brain injury. Recent focus has been on rectification of promising preclinical neuroprotection data and subsequent failed clinical trials. This has led to consensus guidelines for the process of transferring purported therapeutics from bench to bedside. In this review we first examined the history of anesthetic neuroprotection research. Then, a systematic review was performed to identify major clinical trials of anesthetic neuroprotection. Both the preclinical neuroprotection portfolio cited to justify a clinical trial and the design and conduct of that clinical trial were evaluated using modern standards that include the Stroke Therapy Academic Industry Roundtable (STAIR) and Consolidated Standards of Reporting Trials (CONSORT) guidelines. In publications intended to define anesthetic neuroprotection, we found overall poor quality of both preclinical efficacy analysis portfolios and clinical trial designs and conduct. Hence, using current translational research standards, it was not possible to conclude from existing data whether anesthetics ameliorate perioperative ischemic brain injury. Incorporation of advances in translational neuroprotection research conduct may provide a basis for more definitive and potentially successful clinical trials of anesthetics as neuroprotectants.

Preclinical animal research on therapy dosimetry with dual isotopes

NARCIS (Netherlands)

M.W. Konijnenberg (Mark); M. de Jong (Marion)

2011-01-01

textabstractPreclinical research into radionuclide therapies based on radiation dosimetry will enable the use of any LET-equivalent radionuclide. Radiation dose and dose rate have significant influence on dose effects in the tumour depending on its radiation sensitivity, possibilities for repair of

Subjective and Objective Evaluation of PBL Outcomes in Preclinical ...

African Journals Online (AJOL)

Subjective and Objective Evaluation of PBL Outcomes in Preclinical Medical Students. ... ABSTRACT: Problem based learning curriculum is widely recognized as a progressive, learner-centered, active learning approach and is currently used in the entire medical curriculum in over 10% of medical schools worldwide.

A generalizable pre-clinical research approach for orphan disease therapy

Directory of Open Access Journals (Sweden)

Beaulieu Chandree L

2012-06-01

Full Text Available Abstract With the advent of next-generation DNA sequencing, the pace of inherited orphan disease gene identification has increased dramatically, a situation that will continue for at least the next several years. At present, the numbers of such identified disease genes significantly outstrips the number of laboratories available to investigate a given disorder, an asymmetry that will only increase over time. The hope for any genetic disorder is, where possible and in addition to accurate diagnostic test formulation, the development of therapeutic approaches. To this end, we propose here the development of a strategic toolbox and preclinical research pathway for inherited orphan disease. Taking much of what has been learned from rare genetic disease research over the past two decades, we propose generalizable methods utilizing transcriptomic, system-wide chemical biology datasets combined with chemical informatics and, where possible, repurposing of FDA approved drugs for pre-clinical orphan disease therapies. It is hoped that this approach may be of utility for the broader orphan disease research community and provide funding organizations and patient advocacy groups with suggestions for the optimal path forward. In addition to enabling academic pre-clinical research, strategies such as this may also aid in seeding startup companies, as well as further engaging the pharmaceutical industry in the treatment of rare genetic disease.

Targetable vulnerabilities in T- and NK-cell lymphomas identified through preclinical models.

Science.gov (United States)

Ng, Samuel Y; Yoshida, Noriaki; Christie, Amanda L; Ghandi, Mahmoud; Dharia, Neekesh V; Dempster, Joshua; Murakami, Mark; Shigemori, Kay; Morrow, Sara N; Van Scoyk, Alexandria; Cordero, Nicolas A; Stevenson, Kristen E; Puligandla, Maneka; Haas, Brian; Lo, Christopher; Meyers, Robin; Gao, Galen; Cherniack, Andrew; Louissaint, Abner; Nardi, Valentina; Thorner, Aaron R; Long, Henry; Qiu, Xintao; Morgan, Elizabeth A; Dorfman, David M; Fiore, Danilo; Jang, Julie; Epstein, Alan L; Dogan, Ahmet; Zhang, Yanming; Horwitz, Steven M; Jacobsen, Eric D; Santiago, Solimar; Ren, Jian-Guo; Guerlavais, Vincent; Annis, D Allen; Aivado, Manuel; Saleh, Mansoor N; Mehta, Amitkumar; Tsherniak, Aviad; Root, David; Vazquez, Francisca; Hahn, William C; Inghirami, Giorgio; Aster, Jon C; Weinstock, David M; Koch, Raphael

2018-05-22

T- and NK-cell lymphomas (TCL) are a heterogenous group of lymphoid malignancies with poor prognosis. In contrast to B-cell and myeloid malignancies, there are few preclinical models of TCLs, which has hampered the development of effective therapeutics. Here we establish and characterize preclinical models of TCL. We identify multiple vulnerabilities that are targetable with currently available agents (e.g., inhibitors of JAK2 or IKZF1) and demonstrate proof-of-principle for biomarker-driven therapies using patient-derived xenografts (PDXs). We show that MDM2 and MDMX are targetable vulnerabilities within TP53-wild-type TCLs. ALRN-6924, a stapled peptide that blocks interactions between p53 and both MDM2 and MDMX has potent in vitro activity and superior in vivo activity across 8 different PDX models compared to the standard-of-care agent romidepsin. ALRN-6924 induced a complete remission in a patient with TP53-wild-type angioimmunoblastic T-cell lymphoma, demonstrating the potential for rapid translation of discoveries from subtype-specific preclinical models.

Alzheimer's disease prevention: from risk factors to early intervention.

Science.gov (United States)

Crous-Bou, Marta; Minguillón, Carolina; Gramunt, Nina; Molinuevo, José Luis

2017-09-12

Due to the progressive aging of the population, Alzheimer's disease (AD) is becoming a healthcare burden of epidemic proportions for which there is currently no cure. Disappointing results from clinical trials performed in mild-moderate AD dementia combined with clear epidemiological evidence on AD risk factors are contributing to the development of primary prevention initiatives. In addition, the characterization of the long asymptomatic stage of AD is allowing the development of intervention studies and secondary prevention programmes on asymptomatic at-risk individuals, before substantial irreversible neuronal dysfunction and loss have occurred, an approach that emerges as highly relevant.In this manuscript, we review current strategies for AD prevention, from primary prevention strategies based on identifying risk factors and risk reduction, to secondary prevention initiatives based on the early detection of the pathophysiological hallmarks and intervention at the preclinical stage of the disease. Firstly, we summarize the evidence on several AD risk factors, which are the rationale for the establishment of primary prevention programmes as well as revising current primary prevention strategies. Secondly, we review the development of public-private partnerships for disease prevention that aim to characterize the AD continuum as well as serving as platforms for secondary prevention trials. Finally, we summarize currently ongoing clinical trials recruiting participants with preclinical AD or a higher risk for the onset of AD-related cognitive impairment.The growing body of research on the risk factors for AD and its preclinical stage is favouring the development of AD prevention programmes that, by delaying the onset of Alzheimer's dementia for only a few years, would have a huge impact on public health.

Gene and protein patterns of potential prion-related markers in the central nervous system of clinical and preclinical infected sheep

Science.gov (United States)

2013-01-01

The molecular pathogenic mechanisms of prion diseases are far from clear. Genomic analyses have revealed genetic biomarkers potentially involved in prion neuropathology in naturally scrapie-infected sheep, a good animal model of infectious prionopathies. However, these biomarkers must be validated in independent studies at different stages of the disease. The gene and protein expression profiles and protein distribution of six potential genetic biomarkers (i.e., CAPN6, COL1A2, COL3A1, GALA1, MT2A and MTNR1B) are presented here for both the early and terminal stages of scrapie in five different brain regions. Gene transcription changes were confirmed in the medulla oblongata, and the expression profiles were generally similar in other central nervous system regions. The changes were more substantial in clinical animals compared to preclinical animals. The expression of the CAPN6 protein increased in the spinal cord and cerebellum of the clinical and preclinical brains. The distribution of the GALA1 was identified in glial cells from the cerebellum of scrapie-infected animals, GALA1 protein expression was increased in clinical animals in the majority of regions, and the increase of MT2A was in agreement with previous reports. The downregulation of MTNR1B was especially marked in the Purkinje cells. Finally, although collagen genes were downregulated the protein immunostaining did not reveal significant changes between the scrapie-infected and control animals. In conclusion, this study of gene transcription and protein expression and distribution confirm CAPN6, GALA1, MTNR1B and MT2A as potential targets for further prion disease research. PMID:23497022

Early signs of mobility decline and physical activity counseling as a preventive intervention in older people

DEFF Research Database (Denmark)

Mänty, Minna Regina

indicate that self-reported preclinical mobility limitation and fall history should be considered as important early indicators of functional decline among community-dwelling older adults. In addition, the results suggest that physical activity counseling for older adults may provide an effective means......The purpose of this study was to examine the early signs of mobility decline and falls in older people. In addition, the effects of physical activity counseling on the development of mobility limitation in an older community-dwelling population were studied. Data from two larger studies were used......: Screening and Counseling for Physical activity and Mobility among Older People, SCAMOB, a 2-year single-blinded randomized controlled trial (n=632) with a 1.5-year post-intervention follow-up, focused on 75 to 81-year-old community-dwelling people and the FITSA study, a 3-year prospective observational...

Copper-64 Dichloride as Theranostic Agent for Glioblastoma Multiforme: A Preclinical Study

Directory of Open Access Journals (Sweden)

Cristina Ferrari

2015-01-01

Full Text Available Glioblastoma multiforme (GBM is the most common primary malignant brain tumor in adults with a median survival time less than one year. To date, there are only a limited number of effective agents available for GBM therapy and this does not seem to add much survival advantage over the conventional approach based on surgery and radiotherapy. Therefore, the development of novel therapeutic approaches to GBM is essential and those based on radionuclide therapy could be of significant clinical impact. Experimental evidence has clearly demonstrated that cancer cells have a particularly high fractional content of copper inside the nucleus compared to normal cells. This behavior can be conveniently exploited both for diagnosis and for delivering therapeutic payloads (theranostic of the radionuclide copper-64 into the nucleus of cancerous cells by intravenous administration of its simplest chemical form as dichloride salt [64Cu]CuCl2. To evaluate the potential theranostic role of [64Cu]CuCl2 in GBM, the present work reports results from a preclinical study carried out in a xenografted GBM tumor mouse model. Biodistribution data of this new agent were collected using a small-animal PET tomograph. Subsequently, groups of tumor implanted nude mice were treated with [64Cu]CuCl2 to simulate single- and multiple-dose therapy protocols, and results were analyzed to estimate therapeutic efficacy.

Modeling Acute Traumatic Hemorrhagic Shock Injury: Challenges and Guidelines for Preclinical Studies.

Science.gov (United States)

Tremoleda, Jordi L; Watts, Sarah A; Reynolds, Penny S; Thiemermann, Christoph; Brohi, Karim

2017-12-01

Trauma is responsible for a large proportion of the world's burden of disease, and is by far the biggest killer of young adults. Hemorrhage is the leading cause of preventable death and its effects are directly correlated with the incidence multi-organ failure in survivors. Trauma research is challenging due to patient heterogeneity, limited randomized controlled trials, and in vitro studies that fail to mimic the systemic injury response. Preclinical research remains essential for mechanistic and therapeutic discovery. Yet modeling the multifaceted nature of traumatic injury poses important experimental and welfare challenges associated with the onset of injury and prehospital and intra-operative care, the limited inter-species validation of coagulation profiles, the use of anesthesia/analgesia, and its impact on the systemic response to trauma; and the challenge of sustaining intensive care in recovery models. Proper model selection depends on the purpose of a given model and the criteria by which the experimental readouts will be clinically relevant. Such complexity warrants further refinement of experimental methodology and outcome measures to improve its clinical efficacy, while ensuring animal well-being. We review the experimental methodologies currently used for modeling traumatic hemorrhagic shock and addressing their impact on clinical translation. The aim of the review is to improve transparency and form a consensus when reporting methodology in trauma modeling.

Fluorescent Nanoprobes Dedicated to in Vivo Imaging: From Preclinical Validations to Clinical Translation

Directory of Open Access Journals (Sweden)

Isabelle Texier

2012-05-01

Full Text Available With the fast development, in the last ten years, of a large choice of set-ups dedicated to routine in vivo measurements in rodents, fluorescence imaging techniques are becoming essential tools in preclinical studies. Human clinical uses for diagnostic and image-guided surgery are also emerging. In comparison to low-molecular weight organic dyes, the use of fluorescent nanoprobes can improve both the signal sensitivity (better in vivo optical properties and the fluorescence biodistribution (passive “nano” uptake in tumours for instance. A wide range of fluorescent nanoprobes have been designed and tested in preclinical studies for the last few years. They will be reviewed and discussed considering the obstacles that need to be overcome for their potential everyday use in clinics. The conjugation of fluorescence imaging with the benefits of nanotechnology should open the way to new medical applications in the near future.

Pre-clinical cognitive phenotypes for Alzheimer disease: a latent profile approach.

Science.gov (United States)

Hayden, Kathleen M; Kuchibhatla, Maragatha; Romero, Heather R; Plassman, Brenda L; Burke, James R; Browndyke, Jeffrey N; Welsh-Bohmer, Kathleen A

2014-11-01

Cognitive profiles for pre-clinical Alzheimer disease (AD) can be used to identify groups of individuals at risk for disease and better characterize pre-clinical disease. Profiles or patterns of performance as pre-clinical phenotypes may be more useful than individual test scores or measures of global decline. To evaluate patterns of cognitive performance in cognitively normal individuals to derive latent profiles associated with later onset of disease using a combination of factor analysis and latent profile analysis. The National Alzheimer Coordinating Centers collect data, including a battery of neuropsychological tests, from participants at 29 National Institute on Aging-funded Alzheimer Disease Centers across the United States. Prior factor analyses of this battery demonstrated a four-factor structure comprising memory, attention, language, and executive function. Factor scores from these analyses were used in a latent profile approach to characterize cognition among a group of cognitively normal participants (N = 3,911). Associations between latent profiles and disease outcomes an average of 3 years later were evaluated with multinomial regression models. Similar analyses were used to determine predictors of profile membership. Four groups were identified; each with distinct characteristics and significantly associated with later disease outcomes. Two groups were significantly associated with development of cognitive impairment. In post hoc analyses, both the Trail Making Test Part B, and a contrast score (Delayed Recall - Trails B), significantly predicted group membership and later cognitive impairment. Latent profile analysis is a useful method to evaluate patterns of cognition in large samples for the identification of preclinical AD phenotypes; comparable results, however, can be achieved with very sensitive tests and contrast scores. Copyright © 2014 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Prediction of antibiotic resistance: time for a new preclinical paradigm?

DEFF Research Database (Denmark)

Sommer, Morten Otto Alexander; Munck, Christian; Toft-Kehler, Rasmus Vendler

2017-01-01

Predicting the future is difficult, especially for evolutionary processes that are influenced by numerous unknown factors. Still, this is what is required of drug developers when they assess the risk of resistance arising against a new antibiotic candidate during preclinical development. In this ......Predicting the future is difficult, especially for evolutionary processes that are influenced by numerous unknown factors. Still, this is what is required of drug developers when they assess the risk of resistance arising against a new antibiotic candidate during preclinical development....... In this Opinion article, we argue that the traditional procedures that are used for the prediction of antibiotic resistance today could be markedly improved by including a broader analysis of bacterial fitness, infection dynamics, horizontal gene transfer and other factors. This will lead to more informed...

A student-initiated and student-facilitated international health elective for preclinical medical students

Directory of Open Access Journals (Sweden)

Nirali Vora

2010-02-01

Full Text Available Introduction: Global health education is becoming more important for developing well-rounded physicians and may encourage students toward a career in primary care. Many medical schools, however, lack adequate and structured opportunities for students beginning the curriculum. Methods: Second-year medical students initiated, designed, and facilitated a pass–fail international health elective, providing a curricular framework for preclinical medical students wishing to gain exposure to the clinical and cultural practices of a developing country. Results: All course participants (N=30 completed a post-travel questionnaire within one week of sharing their experiences. Screening reflection essays for common themes that fulfill university core competencies yielded specific global health learning outcomes, including analysis of health care determinants. Conclusion: Medical students successfully implemented a sustainable global health curriculum for preclinical student peers. Financial constraints, language, and organizational burdens limit student participation. In future, long-term studies should analyze career impact and benefits to the host country.

Pre-clinical research in small animals using radiotherapy technology--a bidirectional translational approach.

Science.gov (United States)

Tillner, Falk; Thute, Prasad; Bütof, Rebecca; Krause, Mechthild; Enghardt, Wolfgang

2014-12-01

For translational cancer research, pre-clinical in-vivo studies using small animals have become indispensable in bridging the gap between in-vitro cell experiments and clinical implementation. When setting up such small animal experiments, various biological, technical and methodical aspects have to be considered. In this work we present a comprehensive topical review based on relevant publications on irradiation techniques used for pre-clinical cancer research in mice and rats. Clinical radiotherapy treatment devices for the application of external beam radiotherapy and brachytherapy as well as dedicated research irradiation devices are feasible for small animal irradiation depending on the animal model and the experimental goals. In this work, appropriate solutions for the technological transfer of human radiation oncology to small animal radiation research are summarised. Additionally, important information concerning the experimental design is provided such that reliable and clinically relevant results can be attained. Copyright © 2014. Published by Elsevier GmbH.

Microfluidics Enables Small-Scale Tissue-Based Drug Metabolism Studies With Scarce Human Tissue

NARCIS (Netherlands)

van Midwoud, Paul M.; Verpoorte, Elisabeth; Groothuis, Geny M. M.; Merema, M.T.

2011-01-01

Early information on the metabolism and toxicity properties of new drug candidates is crucial for selecting the right candidates for further development. Preclinical trials rely on cell-based in vitro tests and animal studies to characterize the in vivo behavior of drug candidates, although neither

Preclinical Torsades-de-Pointes screens: advantages and limitations of surrogate and direct approaches in evaluating proarrhythmic risk.

Science.gov (United States)

Gintant, Gary A

2008-08-01

The successful development of novel drugs requires the ability to detect (and avoid) compounds that may provoke Torsades-de-Pointes (TdeP) arrhythmia while endorsing those compounds with minimal torsadogenic risk. As TdeP is a rare arrhythmia not readily observed during clinical or post-marketing studies, numerous preclinical models are employed to assess delayed or altered ventricular repolarization (surrogate markers linked to enhanced proarrhythmic risk). This review evaluates the advantages and limitations of selected preclinical models (ranging from the simplest cellular hERG current assay to the more complex in vitro perfused ventricular wedge and Langendorff heart preparations and in vivo chronic atrio-ventricular (AV)-node block model). Specific attention is paid to the utility of concentration-response relationships and "risk signatures" derived from these studies, with the intention of moving beyond predicting clinical QT prolongation and towards prediction of TdeP risk. While the more complex proarrhythmia models may be suited to addressing questionable or conflicting proarrhythmic signals obtained with simpler preclinical assays, further benchmarking of proarrhythmia models is required for their use in the robust evaluation of safety margins. In the future, these models may be able to reduce unwarranted attrition of evolving compounds while becoming pivotal in the balanced integrated risk assessment of advancing compounds.

Lymphoma: current status of clinical and preclinical imaging with radiolabeled antibodies

Energy Technology Data Exchange (ETDEWEB)

England, Christopher G. [University of Wisconsin School of Medicine and Public Health, Department of Medical Physics, Madison, WI (United States); Rui, Lixin [University of Wisconsin School of Medicine and Public Health, Department of Medicine, Madison, WI (United States); University of Wisconsin School of Medicine and Public Health, Carbone Cancer Center, Madison, WI (United States); Cai, Weibo [University of Wisconsin School of Medicine and Public Health, Department of Medical Physics, Madison, WI (United States); University of Wisconsin School of Medicine and Public Health, Carbone Cancer Center, Madison, WI (United States); University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States)

2017-03-15

Lymphoma is a complex disease that arises from cells of the immune system with an intricate pathology. While lymphoma may be classified as Hodgkin or non-Hodgkin, each type of tumor is genetically and phenotypically different and highly invasive tissue biopsies are the only method to investigate these differences. Noninvasive imaging strategies, such as immunoPET, can provide a vital insight into disease staging, monitoring treatment response in patients, and dose planning in radioimmunotherapy. ImmunoPET imaging with radiolabeled antibody-based tracers may also assist physicians in optimizing treatment strategies and enhancing patient stratification. Currently, there are two common biomarkers for molecular imaging of lymphoma, CD20 and CD30, both of which have been considered for investigation in preclinical imaging studies. In this review, we examine the current status of both preclinical and clinical imaging of lymphoma using radiolabeled antibodies. Additionally, we briefly investigate the role of radiolabeled antibodies in lymphoma therapy. As radiolabeled antibodies play critical roles in both imaging and therapy of lymphoma, the development of novel antibodies and the discovery of new biomarkers may greatly affect lymphoma imaging and therapy in the future. (orig.)

Lymphoma: current status of clinical and preclinical imaging with radiolabeled antibodies

International Nuclear Information System (INIS)

England, Christopher G.; Rui, Lixin; Cai, Weibo

2017-01-01

Lymphoma is a complex disease that arises from cells of the immune system with an intricate pathology. While lymphoma may be classified as Hodgkin or non-Hodgkin, each type of tumor is genetically and phenotypically different and highly invasive tissue biopsies are the only method to investigate these differences. Noninvasive imaging strategies, such as immunoPET, can provide a vital insight into disease staging, monitoring treatment response in patients, and dose planning in radioimmunotherapy. ImmunoPET imaging with radiolabeled antibody-based tracers may also assist physicians in optimizing treatment strategies and enhancing patient stratification. Currently, there are two common biomarkers for molecular imaging of lymphoma, CD20 and CD30, both of which have been considered for investigation in preclinical imaging studies. In this review, we examine the current status of both preclinical and clinical imaging of lymphoma using radiolabeled antibodies. Additionally, we briefly investigate the role of radiolabeled antibodies in lymphoma therapy. As radiolabeled antibodies play critical roles in both imaging and therapy of lymphoma, the development of novel antibodies and the discovery of new biomarkers may greatly affect lymphoma imaging and therapy in the future. (orig.)

Osseointegration in osteoporotic-like condition: A systematic review of preclinical studies.

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Dereka, X; Calciolari, E; Donos, N; Mardas, N

2018-05-30

Osteoporosis is one of the most common skeletal disorders affecting a significant percentage of people worldwide. Research data suggested that systemic diseases such as osteoporosis could act as risk factors for osseointegration, jeopardizing the healing process and thus the predictability of dental implant success on compromised patients. It is well accepted that preclinical studies in animal models reproducing the osteoporotic condition are one of the most important stages in the research of new biomaterials and therapeutic modalities. The aim of this systematic review was to investigate whether osteoporosis compromises dental implant osseointegration in experimental osteoporotic-like conditions. A 3-stage systematic literature research was conducted in MEDLINE via OVID and EMBASE up to and including March 2017. Experimental studies reporting on dental implant osseointegration on different osteoporotic animal models were assessed. The studies had to report on the percentage of bone-to-implant contact (%BIC) as the primary outcome. ARRIVE guidelines for reporting on animal research were applied to evaluate the methodological quality and risk of bias of the studies. Fifty-seven studies met the inclusion criteria and were assessed qualitatively. The most adopted animal model was the rat. A variability of %BIC values was observed, ranging from 30% to 99% and from 26% to 94% for the healthy and osteoporotic group, respectively. The great majority (47) of the included studies concluded that estrogen deficiency significantly affects BIC values, 9 studies stated that it was not possible to observe statistical differences in BIC between ovariectomized and healthy groups and 1 study did not provide a comparison between the healthy and osteoporotic group. Owing to the great heterogeneity in implant surface, study design, observation time-points, site of implant placement and reported outcomes, a meta-analysis could not be performed. An overall high risk of bias was observed

[DIFFERENCE IN THE PREVALENCE OF BURNOUT SYNDROME IN PRECLINICAL AND CLINICAL TEACHING DOCTORS OF MOSTAR SCHOOL OF MEDICINE].

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Vukojevič, Mladenka; Antunovič, Andelka; Petrov, Božo

2015-01-01

The aim of this study was to determine the difference in the prevalence of burnout syndrome in preclinical and clinical teaching doctors of Mostar School of Medicine in the academic year 2011/2012. Special attention was also focused on finding out the possible difference between the syndrome incidence that was correlated to gender and years of service. The main hypothesis was that the probability of burnout syndrome incidence was higher in the group of female clinical teaching doctors having more years of service. The study involved 62 people with high academic education employed at Mostar School of Medicine who were surveyed during a randomly selected consecutive 3-month period (February to May) of the academic year 2011/2012. The data were prospectively collected through a standardized questionnaire survey. The studied parameters were gender, years of work experience and the engagement in preclinical or clinical departments of the Medical School. The survey showed that 43 out of 62 (69.4%) respondents did not suffer the burnout syndrome, while moderate syndrome was recodred in 19 (30.6%) of them. No person had serious symptoms of the syndrome. The difference between the respondents who suffered the syndrome and those who did not was not statistically significant (P=0.002). Considering the gender of respondents, statistically significant differences were not confirmed (P=0.444). Considering the years of service, the highest incidence of the syndrome was found in people with more work experience (in the group of 21-25 years), but the difference between the groups was not statistically significant (P=0.271). Observing the work in preclinical and clinical departments, because of the limited number of patients we could not confirm the hypothesis. The syndrome had affected 13 (21%) clinical teaching doctors and 6 (9,7%) preclinical doctors, while the differenece between them was not statistically significant (P=0.054). Considering the results of this research, it has

Recommendations concerning the new U.S. National Institutes of Health initiative to balance the sex of cells and animals in preclinical research.

Science.gov (United States)

Sandberg, Kathryn; Umans, Jason G

2015-05-01

The U.S. National Institutes of Health (NIH) announced last May that steps will be taken to address the over-reliance on male cells and animals in preclinical research. To further address this announcement, in September 2014, scientists with varying perspectives came together at Georgetown University to discuss the following questions. (1) What metrics should the NIH use to assess tangible progress on policy changes designed to address the over-reliance on male cells and animals in preclinical research? (2) How effective can education be in reducing the over-reliance on male cells and animals in preclinical research and what educational initiatives sponsored by the NIH would most likely effect change? (3) What criteria should the NIH use to determine rigorously defined exceptions to the future proposal requirement of a balance of male and female cells and animals in preclinical studies? (4) What additional strategies in addition to proposal requirements should NIH use to reduce the overreliance of male cells and animals in preclinical research? The resulting consensus presented herein includes input from researchers not only from diverse disciplines of basic and translational science including biology, cell and molecular biology, biochemistry, physiology, pharmacology, neuroscience, cardiology, endocrinology, nephrology, psychiatry, and obstetrics and gynecology, but also from recognized experts in publishing, industry, advocacy, science policy, clinical medicine, and population health. We offer our recommendations to aid the NIH as it selects, implements, monitors, and optimizes strategies to correct the over-reliance on male cells and animals in preclinical research. © FASEB.

VARK Learning Preferences and Mobile Anatomy Software Application Use in Pre-Clinical Chiropractic Students

Science.gov (United States)

Meyer, Amanda J.; Stomski, Norman J.; Innes, Stanley I.; Armson, Anthony J.

2016-01-01

Ubiquitous smartphone ownership and reduced face-to-face teaching time may lead to students making greater use of mobile technologies in their learning. This is the first study to report on the prevalence of mobile gross anatomy software applications (apps) usage in pre-clinical chiropractic students and to ascertain if a relationship exists…

[Preclinical study of immunocorrection action of the sum of active substances of Coluria geoides (Pall.) Ledeb. (Rosaceae)].

Science.gov (United States)

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.

Nanotechnology and nuclear medicine; research and preclinical applications.

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Assadi, Majid; Afrasiabi, Kolsoom; Nabipour, Iraj; Seyedabadi, Mohammad

2011-01-01

The birth of nanotechnology in human society was around 2000 years ago and soon found applications in various fields. In this article, we highlight the current status of research and preclinical applications and also future prospects of nanotechnology in medicine and in nuclear medicine. The most important field is cancer. A regular nanotechnology training program for nuclear medicine physicians may be welcome.

Assessment of tobacco heating product THP1.0. Part 9: The placement of a range of next-generation products on an emissions continuum relative to cigarettes via pre-clinical assessment studies.

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Murphy, James; Liu, Chuan; McAdam, Kevin; Gaҫa, Marianna; Prasad, Krishna; Camacho, Oscar; McAughey, John; Proctor, Christopher

2018-03-01

This series of nine papers described the operation and pre-clinical assessment of a tobacco heating product THP1.0. This last paper contextualises the pre-clinical assessment data on THP1.0 with data from other next generation products relative to cigarette smoke. The tobacco and nicotine risk continuum is a concept that ranks products according to their potential harm, with cigarettes at the highest risk extreme and Nicotine Replacement Therapy at the least risky extreme. Data generated in pre-clinical studies on THP1.0 and a range of Next Generation Products (NGPs) may provide some initial indication of potential ranking of these products, although importantly, data from such studies are limited and cannot take into consideration several important aspects for risk such as long term product use patterns. In each of the studies, the responses to the emissions from THP1.0 were substantially reduced relative to cigarette smoke. Additionally, responses from THP1.0 were very similar to those from the other NGP emissions. A comparison of the results clearly showed the emissions from all the NGPs were considerably lower than those from cigarettes and all in around the same emissions level. These results show that THP1.0 could have the potential to be a reduced risk product compared to cigarettes, though further studies assessing the exposure, individual and population risk reduction profile would be required to substantiate this potential. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

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

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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.

Small Molecular TRAIL Inducer ONC201 Induces Death in Lung Cancer Cells: A Preclinical Study.

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Feng, Yuan; Zhou, Jihong; Li, Zhanhua; Jiang, Ying; Zhou, Ying

2016-01-01

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) selectively targets cancer cells. The present preclinical study investigated the anti-cancer efficiency of ONC201, a first-in-class small molecule TRAIL inducer, in lung cancer cells. We showed that ONC201 was cytotoxic and anti-proliferative in both established (A549 and H460 lines) and primary human lung cancer cells. It was yet non-cytotoxic to normal lung epithelial cells. Further, ONC201 induced exogenous apoptosis activation in lung cancer cells, which was evidenced by TRAIL/death receptor-5 (DR5) induction and caspase-8 activation. The caspase-8 inhibitor or TRAIL/DR5 siRNA knockdown alleviated ONC201's cytotoxicity against lung cancer cells. Molecularly, ONC201 in-activated Akt-S6K1 and Erk signalings in lung cancer cells, causing Foxo3a nuclear translocation. For the in vivo studies, intraperitoneal injection of ONC201 at well-tolerated doses significantly inhibited xenografted A549 tumor growth in severe combined immunodeficient (SCID) mice. Further, ONC201 administration induced TRAIL/DR5 expression, yet inactivated Akt-S6K1 and Erk in tumor tissues. These results of the study demonstrates the potent anti-lung cancer activity by ONC201.

Small Molecular TRAIL Inducer ONC201 Induces Death in Lung Cancer Cells: A Preclinical Study.

Directory of Open Access Journals (Sweden)

Yuan Feng

Full Text Available Tumor necrosis factor (TNF-related apoptosis-inducing ligand (TRAIL selectively targets cancer cells. The present preclinical study investigated the anti-cancer efficiency of ONC201, a first-in-class small molecule TRAIL inducer, in lung cancer cells. We showed that ONC201 was cytotoxic and anti-proliferative in both established (A549 and H460 lines and primary human lung cancer cells. It was yet non-cytotoxic to normal lung epithelial cells. Further, ONC201 induced exogenous apoptosis activation in lung cancer cells, which was evidenced by TRAIL/death receptor-5 (DR5 induction and caspase-8 activation. The caspase-8 inhibitor or TRAIL/DR5 siRNA knockdown alleviated ONC201's cytotoxicity against lung cancer cells. Molecularly, ONC201 in-activated Akt-S6K1 and Erk signalings in lung cancer cells, causing Foxo3a nuclear translocation. For the in vivo studies, intraperitoneal injection of ONC201 at well-tolerated doses significantly inhibited xenografted A549 tumor growth in severe combined immunodeficient (SCID mice. Further, ONC201 administration induced TRAIL/DR5 expression, yet inactivated Akt-S6K1 and Erk in tumor tissues. These results of the study demonstrates the potent anti-lung cancer activity by ONC201.

Microbubbles combined with ultrasound therapy in ischemic stroke: A systematic review of in-vivo preclinical studies.

Directory of Open Access Journals (Sweden)

Laurent Auboire

Full Text Available Microbubbles (MBs combined with ultrasound sonothrombolysis (STL appears to be an alternative therapeutic strategy for acute ischemic stroke (IS, but clinical results remain controversial.The aim of this systematic review is to identify the parameters tested; to assess evidence on the safety and efficacy on preclinical data on STL; and to assess the validity and publication bias.Pubmed® and Web of ScienceTM databases were systematically searched from January 1995 to April 2017 in French and English. We included studies evaluating STL on animal stroke model. This systematic review was conducted in accordance with the PRISMA guidelines. Data were extracted following a pre-defined schedule by two of the authors. The CAMARADES criteria were used for quality assessment. A narrative synthesis was conducted.Sixteen studies met the inclusion criteria. The result showed that ultrasound parameters and types of MBs were heterogeneous among studies. Numerous positive outcomes on efficacy were found, but only four studies demonstrated superiority of STL versus recombinant tissue-type plasminogen activator on clinical criteria. Data available on safety are limited.Quality assessment of the studies reviewed revealed a number of biases.Further in vivo studies are needed to demonstrate a better efficacy and safety of STL compared to currently approved therapeutic options.http://syrf.org.uk/protocols/.

SPECT and PET imaging of angiogenesis and arteriogenesis in pre-clinical models of myocardial ischemia and peripheral vascular disease

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Hendrikx, Geert [Maastricht University Medical Centre MUMC+, Department of Nuclear Medicine, Postbox 5800, Maastricht (Netherlands); Maastricht University, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); Voeoe, Stefan [Maastricht University Medical Centre MUMC+, Department of Nuclear Medicine, Postbox 5800, Maastricht (Netherlands); Bauwens, Matthias [Maastricht University Medical Centre MUMC+, Department of Nuclear Medicine, Postbox 5800, Maastricht (Netherlands); Maastricht University, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht (Netherlands); Post, Mark J. [Maastricht University, Department of Physiology, Maastricht (Netherlands); Maastricht University, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); Mottaghy, Felix M. [Maastricht University Medical Centre MUMC+, Department of Nuclear Medicine, Postbox 5800, Maastricht (Netherlands); University Hospital, RWTH Aachen University, Department of Nuclear Medicine, Aachen (Germany)

2016-12-15

The extent of neovascularization determines the clinical outcome of coronary artery disease and other occlusive cardiovascular disorders. Monitoring of neovascularization is therefore highly important. This review article will elaborately discuss preclinical studies aimed at validating new nuclear angiogenesis and arteriogenesis tracers. Additionally, we will briefly address possible obstacles that should be considered when designing an arteriogenesis radiotracer. A structured medline search was the base of this review, which gives an overview on different radiopharmaceuticals that have been evaluated in preclinical models. Neovascularization is a collective term used to indicate different processes such as angiogenesis and arteriogenesis. However, while it is assumed that sensitive detection through nuclear imaging will facilitate translation of successful therapeutic interventions in preclinical models to the bedside, we still lack specific tracers for neovascularization imaging. Most nuclear imaging research to date has focused on angiogenesis, leaving nuclear arteriogenesis imaging largely overlooked. Although angiogenesis is the process which is best understood, there is no scarcity in theoretical targets for arteriogenesis imaging. (orig.)

Problems of early clinical diagnostics of pseudoexfoliation syndrome

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A. Yu. Brezhnev

2012-01-01

Full Text Available Purpose: to study the informativeness of pseudoexfoliation syndrome (PES signs for early diagnosis improvement.Methods: 250 patients with PES were included in the study. Exclusion criteria consisted of aphakia, pseudophakia, previous eye surgery and diseases which can complicate PES diagnostics (uveitis, corneal pathology, ocular injury etc.. Each patient underwent complete ophthalmic examination, including slit-lamp examination under mydriasis, gonioscopy. Confocal microscopy was used as an additional diagnostic method in several patients (Confoscan-4, Nidek.Results: Pseudoexfoliation material was found at the pupillary margin in 64.8% of patients, and on the lens capsule (central disc in 71% of the test subjects. Peripheral depositions were present in almost all PES patients under mydriasis. Pupil dilation has been allowed to establish the diagnosis of PES additionally in 16% of patients. At the «mini-PES»-stage PES material was most frequently found in the superior-nasal quadrant of lens capsule (85.6%. Clinical asymmetry of several signs (pupil diameter, anterior chamber angle pigmentation, IOP level should be taken into consideration in early PES diagnostics.Conclusion: Examination under mydriasis and knowledge of PES micro-signs in some cases has been allowed to suspect PESeven at the preclinical stage.

Comparative assessment of the diets of healthy individuals, subjects with preclinical coronary heart disease and patients with severe heart diseases

International Nuclear Information System (INIS)

Aronov, D.M.; Eganyan, R.A.; Kovaleva, O.F.; Zhidko, N.I.; Danielov, G.Eh.; Rozhnov, A.V.; Shcherbakova, I.A.

1991-01-01

92 males aged 26 to 55 (28 healthy individuals, 45 persons with preclinical coronary heart disease and 19 patients with functional class 1-2 coronary heart disease) were examined to study the peculiarities and dietary patterns of persons with a high physical working capacity and having no typical clinical signs of the disease. All persons were subjected to a complex examination which included questionnarire, myocardial scintigraphy with 201 Tl at a maximum physical loading, echocardiography, coronaroangiography. Certain dietary peculiarities are established in persons with preclinical coronary heart disease

High-resolution mutational profiling suggests the genetic validity of glioblastoma patient-derived pre-clinical models.

Directory of Open Access Journals (Sweden)

Shawn E Yost

Full Text Available Recent advances in the ability to efficiently characterize tumor genomes is enabling targeted drug development, which requires rigorous biomarker-based patient selection to increase effectiveness. Consequently, representative DNA biomarkers become equally important in pre-clinical studies. However, it is still unclear how well these markers are maintained between the primary tumor and the patient-derived tumor models. Here, we report the comprehensive identification of somatic coding mutations and copy number aberrations in four glioblastoma (GBM primary tumors and their matched pre-clinical models: serum-free neurospheres, adherent cell cultures, and mouse xenografts. We developed innovative methods to improve the data quality and allow a strict comparison of matched tumor samples. Our analysis identifies known GBM mutations altering PTEN and TP53 genes, and new actionable mutations such as the loss of PIK3R1, and reveals clear patient-to-patient differences. In contrast, for each patient, we do not observe any significant remodeling of the mutational profile between primary to model tumors and the few discrepancies can be attributed to stochastic errors or differences in sample purity. Similarly, we observe ∼96% primary-to-model concordance in copy number calls in the high-cellularity samples. In contrast to previous reports based on gene expression profiles, we do not observe significant differences at the DNA level between in vitro compared to in vivo models. This study suggests, at a remarkable resolution, the genome-wide conservation of a patient's tumor genetics in various pre-clinical models, and therefore supports their use for the development and testing of personalized targeted therapies.

Ensuring transparency and minimization of methodologic bias in preclinical pain research: PPRECISE considerations.

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Andrews, Nick A; Latrémolière, Alban; Basbaum, Allan I; Mogil, Jeffrey S; Porreca, Frank; Rice, Andrew S C; Woolf, Clifford J; Currie, Gillian L; Dworkin, Robert H; Eisenach, James C; Evans, Scott; Gewandter, Jennifer S; Gover, Tony D; Handwerker, Hermann; Huang, Wenlong; Iyengar, Smriti; Jensen, Mark P; Kennedy, Jeffrey D; Lee, Nancy; Levine, Jon; Lidster, Katie; Machin, Ian; McDermott, Michael P; McMahon, Stephen B; Price, Theodore J; Ross, Sarah E; Scherrer, Grégory; Seal, Rebecca P; Sena, Emily S; Silva, Elizabeth; Stone, Laura; Svensson, Camilla I; Turk, Dennis C; Whiteside, Garth

2016-04-01

There is growing concern about lack of scientific rigor and transparent reporting across many preclinical fields of biological research. Poor experimental design and lack of transparent reporting can result in conscious or unconscious experimental bias, producing results that are not replicable. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the U.S. Food and Drug Administration sponsored a consensus meeting of the Preclinical Pain Research Consortium for Investigating Safety and Efficacy (PPRECISE) Working Group. International participants from universities, funding agencies, government agencies, industry, and a patient advocacy organization attended. Reduction of publication bias, increasing the ability of others to faithfully repeat experimental methods, and increased transparency of data reporting were specifically discussed. Parameters deemed essential to increase confidence in the published literature were clear, specific reporting of an a priori hypothesis and definition of primary outcome measure. Power calculations and whether measurement of minimal meaningful effect size to determine these should be a core component of the preclinical research effort provoked considerable discussion, with many but not all agreeing. Greater transparency of reporting should be driven by scientists, journal editors, reviewers, and grant funders. The conduct of high-quality science that is fully reported should not preclude novelty and innovation in preclinical pain research, and indeed, any efforts that curtail such innovation would be misguided. We believe that to achieve the goal of finding effective new treatments for patients with pain, the pain field needs to deal with these challenging issues.

The detection, diagnosis, therapy, and pre-clinical biology of breast cancer

International Nuclear Information System (INIS)

1978-01-01

The Cancergram covers clinical aspects of cancers of the mammary glands, the fat pads and the supporting tissues. Abstracts included concern certain specific types of neoplasms which occur in the breast, and in ancillary tissues related to the breast (axillary lymph nodes, etc.). Also included are selected studies on receptors and the physiological aspects of lactation, pregnancy, and ontogeny related to cancer of the breast. The topic includes clinically relevant aspects of the prevention, detection, diagnosis, evaluation, and therapy of breast cancer. With certain exceptions, pre-clinical studies of tissue culture systems or animal model studies which are not directly related to primary human disease are excluded

Altered hemodynamics and hyperuricemia accompany an elevated sFlt-1/PlGF ratio before the onset of early severe preeclampsia.

LENUS (Irish Health Repository)

Doherty, Anne

2014-08-01

Early identification of women at risk of developing early-onset severe preeclampsia (sPE) is a key objective in obstetrics. An elevated ratio of serum soluble fms-like tyrosine kinase (sFlt-1) to placenta-like growth factor (PlGF) (sFlt-1\\/PlGF ratio) precedes overt hypertension. The longitudinal relationship between this biomarker, maternal hemodynamics, and maternal serum uric acid during the pre-clinical phase is unknown.

JAK2 inhibitor therapy in myeloproliferative disorders: rationale, preclinical studies and ongoing clinical trials.

Science.gov (United States)

Pardanani, A

2008-01-01

The recent identification of somatic mutations such as JAK2V617F that deregulate Janus kinase (JAK)-signal transducer and activator of transcription signaling has spurred development of orally bioavailable small-molecule inhibitors that selectively target JAK2 kinase as an approach to pathogenesis-directed therapy of myeloproliferative disorders (MPD). In pre-clinical studies, these compounds inhibit JAK2V617F-mediated cell growth at nanomolar concentrations, and in vivo therapeutic efficacy has been demonstrated in mouse models of JAK2V617F-induced disease. In addition, ex vivo growth of progenitor cells from MPD patients harboring JAK2V617F or MPLW515L/K mutations is also potently inhibited. JAK2 inhibitors currently in clinical trials can be grouped into those designed to primarily target JAK2 kinase (JAK2-selective) and those originally developed for non-MPD indications, but that nevertheless have significant JAK2-inhibitory activity (non-JAK2 selective). This article discusses the rationale for using JAK2 inhibitors for the treatment of MPD, as well as relevant aspects of clinical trial development for these patients. For instance, which group of MPD patients is appropriate for initial Phase I studies? Should JAK2V617F-negative MPD patients be included in the initial studies? What are the likely consequences of 'off-target' JAK3 and wild-type JAK2 inhibition? How should treatment responses be monitored?

Early decision-analytic modeling - a case study on vascular closure devices.

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Brandes, Alina; Sinner, Moritz F; Kääb, Stefan; Rogowski, Wolf H

2015-10-27

As economic considerations become more important in healthcare reimbursement, decisions about the further development of medical innovations need to take into account not only medical need and potential clinical effectiveness, but also cost-effectiveness. Already early in the innovation process economic evaluations can support decisions on development in specific indications or patient groups by anticipating future reimbursement and implementation decisions. One potential concept for early assessment is value-based pricing. The objective is to assess the feasibility of value-based pricing and product design for a hypothetical vascular closure device in the pre-clinical stage which aims at decreasing bleeding events. A deterministic decision-analytic model was developed to estimate the cost-effectiveness of established vascular closure devices from the perspective of the Statutory Health Insurance system. To identify early benchmarks for pricing and product design, three strategies of determining the product's value are explored: 1) savings from complications avoided by the new device; 2) valuation of the avoided complications based on an assumed willingness-to-pay-threshold (the efficiency frontier approach); 3) value associated with modifying the care pathways within which the device would be applied. Use of established vascular closure devices is dominated by manual compression. The hypothetical vascular closure device reduces overall complication rates at higher costs than manual compression. Maximum cost savings of only about €4 per catheterization could be realized by applying the hypothetical device. Extrapolation of an efficiency frontier is only possible for one subgroup where vascular closure devices are not a dominated strategy. Modifying care in terms of same-day discharge of patients treated with vascular closure devices could result in cost savings of €400-600 per catheterization. It was partially feasible to calculate value-based prices for the

Microarray profiling shows distinct differences between primary tumors and commonly used preclinical models in hepatocellular carcinoma

International Nuclear Information System (INIS)

Wang, Weining; Iyer, N. Gopalakrishna; Tay, Hsien Ts’ung; Wu, Yonghui; Lim, Tony K. H.; Zheng, Lin; Song, In Chin; Kwoh, Chee Keong; Huynh, Hung; Tan, Patrick O. B.; Chow, Pierce K. H.

2015-01-01

Despite advances in therapeutics, outcomes for hepatocellular carcinoma (HCC) remain poor and there is an urgent need for efficacious systemic therapy. Unfortunately, drugs that are successful in preclinical studies often fail in the clinical setting, and we hypothesize that this is due to functional differences between primary tumors and commonly used preclinical models. In this study, we attempt to answer this question by comparing tumor morphology and gene expression profiles between primary tumors, xenografts and HCC cell lines. Hep G2 cell lines and tumor cells from patient tumor explants were subcutaneously (ectopically) injected into the flank and orthotopically into liver parenchyma of Mus Musculus SCID mice. The mice were euthanized after two weeks. RNA was extracted from the tumors, and gene expression profiling was performed using the Gene Chip Human Genome U133 Plus 2.0. Principal component analyses (PCA) and construction of dendrograms were conducted using Partek genomics suite. PCA showed that the commonly used HepG2 cell line model and its xenograft counterparts were vastly different from all fresh primary tumors. Expression profiles of primary tumors were also significantly divergent from their counterpart patient-derived xenograft (PDX) models, regardless of the site of implantation. Xenografts from the same primary tumors were more likely to cluster together regardless of site of implantation, although heat maps showed distinct differences in gene expression profiles between orthotopic and ectopic models. The data presented here challenges the utility of routinely used preclinical models. Models using HepG2 were vastly different from primary tumors and PDXs, suggesting that this is not clinically representative. Surprisingly, site of implantation (orthotopic versus ectopic) resulted in limited impact on gene expression profiles, and in both scenarios xenografts differed significantly from the original primary tumors, challenging the long

Manufacture of Third-Generation Lentivirus for Preclinical Use, with Process Development Considerations for Translation to Good Manufacturing Practice.

Science.gov (United States)

Gándara, Carolina; Affleck, Valerie; Stoll, Elizabeth Ann

2018-02-01

Lentiviral vectors are used in laboratories around the world for in vivo and ex vivo delivery of gene therapies, and increasingly clinical investigation as well as preclinical applications. The third-generation lentiviral vector system has many advantages, including high packaging capacity, stable gene expression in both dividing and post-mitotic cells, and low immunogenicity in the recipient organism. Yet, the manufacture of these vectors is challenging, especially at high titers required for direct use in vivo, and further challenges are presented by the process of translating preclinical gene therapies toward manufacture of products for clinical investigation. The goals of this paper are to report the protocol for manufacturing high-titer third-generation lentivirus for preclinical testing and to provide detailed information on considerations for translating preclinical viral vector manufacture toward scaled-up platforms and processes in order to make gene therapies under Good Manufacturing Practice that are suitable for clinical trials.

A preclinical mouse model of invasive lobular breast cancer metastasis

NARCIS (Netherlands)

Doornebal, Chris W.; Klarenbeek, Sjoerd; Braumuller, Tanya M.; Klijn, Christiaan N.; Ciampricotti, Metamia; Hau, Cheei-Sing; Hollmann, Markus W.; Jonkers, Jos; de Visser, Karin E.

2013-01-01

Metastatic disease accounts for more than 90% of cancer-related deaths, but the development of effective antimetastatic agents has been hampered by the paucity of clinically relevant preclinical models of human metastatic disease. Here, we report the development of a mouse model of spontaneous

Altered whole-brain white matter networks in preclinical Alzheimer's disease

Directory of Open Access Journals (Sweden)

Florian Udo Fischer

2015-01-01

Our results suggest an impairment of WM networks in preclinical AD that is detectable while other structural imaging markers do not yet indicate incipient neurodegeneration. Moreover, these findings are specific to WM networks and cannot be explained by other surrogates of global WM integrity.

Effects of spatial and spectral frequencies on wide-field functional imaging (wifi) characterization of preclinical breast cancer models

Science.gov (United States)

Moy, Austin; Kim, Jae G.; Lee, Eva Y. H. P.; Choi, Bernard

2010-02-01

A common strategy to study breast cancer is the use of the preclinical model. These models provide a physiologically relevant and controlled environment in which to study both response to novel treatments and the biology of the cancer. Preclinical models, including the spontaneous tumor model and mammary window chamber model, are very amenable to optical imaging and to this end, we have developed a wide-field functional imaging (WiFI) instrument that is perfectly suited to studying tumor metabolism in preclinical models. WiFI combines two optical imaging modalities, spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI). Our current WiFI imaging protocol consists of multispectral imaging in the near infrared (650-980 nm) spectrum, over a wide (7 cm x 5 cm) field of view. Using SFDI, the spatially-resolved reflectance of sinusoidal patterns projected onto the tissue is assessed, and optical properties of the tissue are determined, which are then used to extract tissue chromophore concentrations in the form of oxy-, deoxy-, and total hemoglobin concentrations, and percentage of lipid and water. In the current study, we employ Monte Carlo simulations of SFDI light propagation in order to characterize the penetration depth of light in both the spontaneous tumor model and mammary window chamber model. Preliminary results suggest that different spatial frequency and wavelength combinations have different penetration depths, suggesting the potential depth sectioning capability of the SFDI component of WiFI.

Preclinical evaluations of norcantharidin-loaded intravenous lipid microspheres with low toxicity.

Science.gov (United States)

Lin, Xia; Zhang, Bo; Zhang, Keru; Zhang, Yu; Wang, Juan; Qi, Na; Yang, Shenshen; He, Haibing; Tang, Xing

2012-12-01

The aim of this study was to perform a systematic preclinical evaluation of norcantharidin (NCTD)-loaded intravenous lipid microspheres (NLM). Pharmacokinetics, biodistribution, antitumor efficacy and drug safety assessment (including acute toxicity, subchronic toxicity, hemolysis testing, intravenous stimulation and injection anaphylaxis) of NLM were carried out in comparison with the commercial product disodium norcantharidate injection (NI). The pharmacokinetics of NLM in rats was similar to that of NI, and a non-linear correlation was observed between AUC and dose. A comparable antitumor efficacy of NLM and NI was observed in mice inoculated with A549, BEL7402 and BCAP-37 cell lines. It was worth noting that the NLM produced a lower drug concentration in heart compared with NI, and significantly reduced the cardiac and renal toxicity. The LD(50) of NLM was twice higher than that of NI. In NLM, over 80% of NCTD was loaded in the lipid phase or bound with phospholipids. Thus, NCTD was sequestered by direct contacting with body fluids and largely avoided distribution into tissues, consequently leading to significantly reduced cardiac and renal toxicity. These preclinical results suggested that NLM could be a useful potential carrier for parenteral administration of NCTD, while providing a superior safety profile.

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

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Grafström, Jonas; Ahlzén, Hanna-Stina [Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm (Sweden); Stone-Elander, Sharon [Department of Clinical Neuroscience, Karolinska Institutet, SE-17176 Stockholm (Sweden); PET Radiochemistry, Neuroradiology Department, Karolinska University Hospital, SE-17176 Stockholm (Sweden)

2015-09-08

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Physiological remodeling of bifurcation aneurysms: preclinical results of the eCLIPs device.

Science.gov (United States)

Marotta, Thomas R; Riina, Howard A; McDougall, Ian; Ricci, Donald R; Killer-Oberpfalzer, Monika

2018-02-01

OBJECTIVE Intracranial bifurcation aneurysms are complex lesions for which current therapy, including simple coiling, balloon- or stent-assisted coiling, coil retention, or intrasaccular devices, is inadequate. Thromboembolic complications due to a large burden of intraluminal metal, impedance of access to side branches, and a high recurrence rate, due largely to the unmitigated high-pressure flow into the aneurysm (water hammer effect), are among the limitations imposed by current therapy. The authors describe herein a novel device, eCLIPs, and its use in a preclinical laboratory study that suggests the device's design and functional features may overcome many of these limitations. METHODS A preclinical model of wide-necked bifurcation aneurysms in rabbits was used to assess functional features and efficacy of aneurysm occlusion by the eCLIPs device. RESULTS The eCLIPs device, in bridging the aneurysm neck, allows coil retention, disrupts flow away from the aneurysm, leaves the main vessel and side branches unencumbered by intraluminal metal, and serves as a platform for endothelial growth across the neck, excluding the aneurysm from the circulation. CONCLUSIONS The eCLIPs device permits physiological remodeling of the bifurcation.

Disclosure of amyloid status is not a barrier to recruitment in preclinical Alzheimer's disease clinical trials.

Science.gov (United States)

Grill, Joshua D; Zhou, Yan; Elashoff, David; Karlawish, Jason

2016-03-01

Preclinical Alzheimer's disease (AD) clinical trials may require participants to learn if they meet biomarker enrollment criteria. To examine whether this requirement will impact trial recruitment, we presented 132 older community volunteers who self-reported normal cognition with 1 of 2 hypothetical informed consent forms (ICFs) describing an AD prevention clinical trial. Both ICFs described amyloid Positron Emission Tomography scans. One ICF stated that scan results would not be shared with the participants (blinded enrollment); the other stated that only persons with elevated amyloid would be eligible (transparent enrollment). Participants rated their likelihood of enrollment and completed an interview with a research assistant. We found no difference between the groups in willingness to participate. Study risks and the requirement of a study partner were reported as the most important factors in the decision whether to enroll. The requirement of biomarker disclosure may not slow recruitment to preclinical AD trials. Copyright © 2016 Elsevier Inc. All rights reserved.

Advances in breast cancer treatment and prevention: preclinical studies on aromatase inhibitors and new selective estrogen receptor modulators (SERMs)

International Nuclear Information System (INIS)

Schiff, Rachel; Chamness, Gary C; Brown, Powel H

2003-01-01

Intensive basic and clinical research over the past 20 years has yielded crucial molecular understanding into how estrogen and the estrogen receptor act to regulate breast cancer and has led to the development of more effective, less toxic, and safer hormonal therapy agents for breast cancer management and prevention. Selective potent aromatase inhibitors are now challenging the hitherto gold standard of hormonal therapy, the selective estrogen-receptor modulator tamoxifen. Furthermore, new selective estrogen-receptor modulators such as arzoxifene, currently under clinical development, offer the possibility of selecting one with a more ideal pharmacological profile for treatment and prevention of breast cancer. Two recent studies in preclinical model systems that evaluate mechanisms of action of these new drugs and suggestions about their optimal clinical use are discussed

Preclinical and clinical investigation of a CCR5 antagonist, AZD5672, in patients with rheumatoid arthritis receiving methotrexate

NARCIS (Netherlands)

Gerlag, Daniëlle M.; Hollis, Sally; Layton, Mark; Vencovský, Jiří; Szekanecz, Zoltán; Braddock, Martin; Tak, Paul P.; Oparanov, Boycho; Stoilov, Rumen; Yaneva, Tanya; Batalov, Anastas; Arteaga, Edgardo Tobias; Escalante, William Otero; Velez, Patricia; Restrepo, Jose Molina; Augustinova, Sevda; Blahova, Anna; Dvorak, Zdenek; Novosad, Libor; Rosa, Jan; Stehlikova, Helena; Vitek, Petr; Balazs, Tibor; Seregely, Katalin; Szombati, Istvan; Tarjan, Katalin; Csengei, Gabor; Galeazzi, Mauro; Saleniece, Sarmite; Saulite-Kandevica, Daina; Coleiro, Bernard; Badurski, Janusz; Brzosko, Marek; Chudzik, Dariusz; Gruszecka-Marczynska, Katarzyna; Hensel, Joanna; Pokrzywnicka-Gajek, Ines; Korpanty-Danda, Joanna; Sochocka-Bykowska, Malgorzata; Tlustochowicz, Witold; Stopinska-Polaszewska, Maria; Gluszko, Piotr; Nedelcovici, Corina; Radulescu, Florin; Gavrila, Mirea; Tanasescu, Coman; Korshunov, Nikolay; Matsievskaia, Galina; Damjanov, Nemanja; Dimic, Aleksandar

2010-01-01

To investigate both the preclinical effects of blocking the chemokine receptor CCR5 and the clinical effects of this approach on the signs and symptoms of rheumatoid arthritis (RA) in patients with active disease. Preclinical evaluations of AZD5672, a small-molecule antagonist of CCR5, were

Gram-scale synthesis of the p38α MAPK-inhibitor VX-745 for preclinical studies into Werner syndrome.

Science.gov (United States)

Bagley, Mark C; Davis, Terence; Dix, Matthew C; Fusillo, Vincenzo; Pigeaux, Morgane; Rokicki, Michal J; Kipling, David

2010-09-01

The ATP-competitive p38α MAPK inhibitor VX-745 exhibits an exquisite kinase selectivity profile, is effective in blocking p38 stress signaling in Werner syndrome dermal fibroblasts, has efficacy in clinical trials and may have therapeutic value against Werner syndrome. Previous synthetic routes, however, have only resulted in milligram quantities suitable for cell-based studies, whereas gram quantities would be required for in vivo use. Microwave irradiation using a stop-flow monomodal microwave reactor has been found to facilitate scale-up of the synthesis of VX-745. Ullmann-type C-S bond formation using thiophenol, chloropyridazine, copper(I) catalyst and diol ligand proceeds rapidly and efficiently in this apparatus for elaboration to the pyrimido[1,6-b]pyridazinone core of VX-745 on gram scale and with good overall yield. This method delivers the p38 inhibitor VX-745 in sufficient quantities for preclinical studies to rescue the aging phenotype in Werner syndrome.

The impact of data integrity on decision making in early lead discovery

Science.gov (United States)

Beck, Bernd; Seeliger, Daniel; Kriegl, Jan M.

2015-09-01

Data driven decision making is a key element of today's pharmaceutical research, including early drug discovery. It comprises questions like which target to pursue, which chemical series to pursue, which compound to make next, or which compound to select for advanced profiling and promotion to pre-clinical development. In the following paper we will exemplify how data integrity, i.e. the context data is generated in and auxiliary information that is provided for individual result records, can influence decision making in early lead discovery programs. In addition we will describe some approaches which we pursue at Boehringer Ingelheim to reduce the risk for getting misguided.

Preclinical imaging in animal models of radiation therapy; Praeklinische Bildgebung im Tiermodell bei Strahlentherapie

Energy Technology Data Exchange (ETDEWEB)

Nikolaou, K.; Cyran, C.C.; Reiser, M.F.; Clevert, D.-A. [Klinikum der Ludwig-Maximilians-Universitaet, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Lauber, K. [Klinikum der Ludwig-Maximilians-Universitaet, Klinik und Poliklinik fuer Strahlentherapie, Muenchen (Germany)

2012-03-15

Modern radiotherapy benefits from precise and targeted diagnostic and pretherapeutic imaging. Standard imaging modalities, such as computed tomography (CT) offer high morphological detail but only limited functional information on tumors. Novel functional and molecular imaging modalities provide biological information about tumors in addition to detailed morphological information. Perfusion magnetic resonance imaging (MRI) CT or ultrasound-based perfusion imaging as well as hybrid modalities, such as positron emission tomography (PET) CT or MRI-PET have the potential to identify and precisely delineate viable and/or perfused tumor areas, enabling optimization of targeted radiotherapy. Functional information on tissue microcirculation and/or glucose metabolism allow a more precise definition and treatment of tumors while reducing the radiation dose and sparing the surrounding healthy tissue. In the development of new imaging methods for planning individualized radiotherapy, preclinical imaging and research plays a pivotal role, as the value of multimodality imaging can only be assessed, tested and adequately developed in a preclinical setting, i.e. in animal tumor models. New functional imaging modalities will play an increasing role for the surveillance of early treatment response during radiation therapy and in the assessment of the potential value of new combination therapies (e.g. combining anti-angiogenic drugs with radiotherapy). (orig.) [German] Die moderne Strahlentherapie profitiert massgeblich von einer detaillierten wie auch funktionellen praetherapeutischen Bildgebung. Die ueblicherweise praetherapeutisch eingesetzten radiologischen Standardverfahren wie die Computertomographie liefern zwar hochwertige morphologische Details, jedoch keine funktionelle Information. Es ist somit ein zunehmender Bedarf an funktionellen und molekularen Bildgebungsmodalitaeten feststellbar, mit denen ergaenzend zur morphologischen Bildgebung auch biologisch

A preclinical cognitive test battery to parallel the National Institute of Health Toolbox in humans: bridging the translational gap.

Science.gov (United States)

Snigdha, Shikha; Milgram, Norton W; Willis, Sherry L; Albert, Marylin; Weintraub, S; Fortin, Norbert J; Cotman, Carl W

2013-07-01

A major goal of animal research is to identify interventions that can promote successful aging and delay or reverse age-related cognitive decline in humans. Recent advances in standardizing cognitive assessment tools for humans have the potential to bring preclinical work closer to human research in aging and Alzheimer's disease. The National Institute of Health (NIH) has led an initiative to develop a comprehensive Toolbox for Neurologic Behavioral Function (NIH Toolbox) to evaluate cognitive, motor, sensory and emotional function for use in epidemiologic and clinical studies spanning 3 to 85 years of age. This paper aims to analyze the strengths and limitations of animal behavioral tests that can be used to parallel those in the NIH Toolbox. We conclude that there are several paradigms available to define a preclinical battery that parallels the NIH Toolbox. We also suggest areas in which new tests may benefit the development of a comprehensive preclinical test battery for assessment of cognitive function in animal models of aging and Alzheimer's disease. Copyright © 2013 Elsevier Inc. All rights reserved.

Palifermin for the protection and regeneration of epithelial tissues following injury: new findings in basic research and pre-clinical models.

Science.gov (United States)

Finch, Paul W; Mark Cross, Lawrence J; McAuley, Daniel F; Farrell, Catherine L

2013-09-01

Keratinocyte growth factor (KGF) is a paracrine-acting epithelial mitogen produced by cells of mesenchymal origin, that plays an important role in protecting and repairing epithelial tissues. Pre-clinical data initially demonstrated that a recombinant truncated KGF (palifermin) could reduce gastrointestinal injury and mortality resulting from a variety of toxic exposures. Furthermore, the use of palifermin in patients with hematological malignancies reduced the incidence and duration of severe oral mucositis experienced after intensive chemoradiotherapy. Based upon these findings, as well as the observation that KGF receptors are expressed in many, if not all, epithelial tissues, pre-clinical studies have been conducted to determine the efficacy of palifermin in protecting different epithelial tissues from toxic injury in an attempt to model various clinical situations in which it might prove to be of benefit in limiting tissue damage. In this article, we review these studies to provide the pre-clinical background for clinical trials that are described in the accompanying article and the rationale for additional clinical applications of palifermin. © 2013 The Authors. Journal of Cellular and Molecular Medicine Published by Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

Preclinical detection of porcine circovirus type 2 infection using an ultrasensitive nanoparticle DNA probe-based PCR assay.

Directory of Open Access Journals (Sweden)

Yong Huang

Full Text Available Porcine circovirus type 2 (PCV2 has emerged as one of the most important pathogens affecting swine production globally. Preclinical identification of PCV2 is very important for effective prophylaxis of PCV2-associated diseases. In this study, we developed an ultrasensitive nanoparticle DNA probe-based PCR assay (UNDP-PCR for PCV2 detection. Magnetic microparticles coated with PCV2 specific DNA probes were used to enrich PCV2 DNA from samples, then gold nanoparticles coated with PCV2 specific oligonucleotides were added to form a sandwich nucleic acid-complex. After the complex was formed, the oligonucleotides were released and characterized by PCR. This assay exhibited about 500-fold more sensitive than conventional PCR, with a detection limit of 2 copies of purified PCV2 genomic DNA and 10 viral copies of PCV2 in serum. The assay has a wide detection range for all of PCV2 genotypes with reliable reproducibility. No cross-reactivity was observed from the samples of other related viruses including porcine circovirus type 1, porcine parvovirus, porcine pseudorabies virus, porcine reproductive and respiratory syndrome virus and classical swine fever virus. The positive detection rate of PCV2 specific UNDP-PCR in 40 preclinical field samples was 27.5%, which appeared greater than that by conventional and real-time PCR and appeared application potency in evaluation of the viral loads levels of preclinical infection samples. The UNDP-PCR assay reported here can reliably rule out false negative results from antibody-based assays, provide a nucleic acid extraction free, specific, ultrasensitive, economic and rapid diagnosis method for preclinical PCV2 infection in field, which may help prevent large-scale outbreaks.

The value of integrating pre-clinical data to predict nausea and vomiting risk in humans as illustrated by AZD3514, a novel androgen receptor modulator

Energy Technology Data Exchange (ETDEWEB)

Grant, Claire, E-mail: claire.grant@astrazeneca.com [Drug Safety and Metabolism, AstraZeneca, Alderley Park, Macclesfield SK10 4TG (United Kingdom); Ewart, Lorna [Drug Safety and Metabolism, AstraZeneca, Da Vinci Building, Melbourn Science Park, Cambridge Road, Melbourn, Royston SG8 6HB (United Kingdom); Muthas, Daniel [Respiratory, Inflammation and Autoimmunity iMED, AstraZeneca, Pepparedsleden 1, 431 83 Mölndal (Sweden); Deavall, Damian [Drug Safety and Metabolism, AstraZeneca, Alderley Park, Macclesfield SK10 4TG (United Kingdom); Smith, Simon A. [Oncology Translational Medicine Unit, Early Clinical Development, AstraZeneca, Da Vinci Building, Melbourn Science Park, Melbourn, Royston SG8 6HB (United Kingdom); Clack, Glen [Translational Medicine Unit, Early Clinical Development, AstraZeneca, Alderley Park, Macclesfield SK10 4TG (United Kingdom); Newham, Pete [Drug Safety and Metabolism, AstraZeneca, Darwin Building, Cambridge Science Park, Milton Road, Cambridge CB4 0WG (United Kingdom)

2016-04-01

Nausea and vomiting are components of a complex mechanism that signals food avoidance and protection of the body against the absorption of ingested toxins. This response can also be triggered by pharmaceuticals. Predicting clinical nausea and vomiting liability for pharmaceutical agents based on pre-clinical data can be problematic as no single animal model is a universal predictor. Moreover, efforts to improve models are hampered by the lack of translational animal and human data in the public domain. AZD3514 is a novel, orally-administered compound that inhibits androgen receptor signaling and down-regulates androgen receptor expression. Here we have explored the utility of integrating data from several pre-clinical models to predict nausea and vomiting in the clinic. Single and repeat doses of AZD3514 resulted in emesis, salivation and gastrointestinal disturbances in the dog, and inhibited gastric emptying in rats after a single dose. AZD3514, at clinically relevant exposures, induced dose-responsive “pica” behaviour in rats after single and multiple daily doses, and induced retching and vomiting behaviour in ferrets after a single dose. We compare these data with the clinical manifestation of nausea and vomiting encountered in patients with castration-resistant prostate cancer receiving AZD3514. Our data reveal a striking relationship between the pre-clinical observations described and the experience of nausea and vomiting in the clinic. In conclusion, the emetic nature of AZD3514 was predicted across a range of pre-clinical models, and the approach presented provides a valuable framework for predicition of clinical nausea and vomiting. - Highlights: • Integrated pre-clinical data can be used to predict clinical nausea and vomiting. • Data integrated from standard toxicology studies is sufficient to make a prediction. • The use of the nausea algorithm developed by Parkinson (2012) aids the prediction. • Additional pre-clinical studies can be used

Bridging the gap between basic and applied biology: towards preclinical translation

Directory of Open Access Journals (Sweden)

Ross L. Cagan

2013-05-01

To better translate basic research findings into the clinic, we are moving away from the traditional one-gene–one-phenotype model towards the discovery of complex mechanisms. In this Editorial, the new Editor-in-Chief and Senior Editors of Disease Models & Mechanisms (DMM discuss the role that the journal will play in this transition. DMM will continue to provide a platform for studies that bridge basic and applied science, and, by demanding the rigorous assessment of animal models of disease, will help drive the establishment of robust standards of preclinical testing for drug development.

Pre-clinical and clinical development of the first placental malaria vaccine

DEFF Research Database (Denmark)

Pehrson, Caroline; Salanti, Ali; Theander, Thor G

2017-01-01

the condition.  Areas covered: Pub Med was searched using the broad terms 'malaria parasite placenta' to identify studies of interactions between parasite and host, 'prevention of placental malaria' to identify current strategies to prevent placental malaria, and 'placental malaria vaccine' to identify pre-clinical...... vaccine development. However, all papers from these searches were not systematically included.  Expert commentary: The first phase I clinical trials of vaccines are well underway. Trials testing efficacy are more complicated to carry out as only women that are exposed to parasites during pregnancy...

[Studies of biologic activation associated with molecular receptor increase and tumor response in ChL6/L6 protocol patients; Studies in phantoms; Quantitative SPECT; Preclinical studies; and Clinical studies]. DOE annual report, 1994-95

International Nuclear Information System (INIS)

DeNardo, S.J.

1995-01-01

The authors describe results which have not yet been published from their associated studies listed in the title. For the first, they discuss Lym-1 single chain genetically engineered molecules, analysis of molecular genetic coded messages to enhance tumor response, and human dosimetry and therapeutic human use radiopharmaceuticals. Studies in phantoms includes a discussion of planar image quantitation, counts coincidence correction, organ studies, tumor studies, and 90 Y quantitation with Bremsstrahlung imaging. The study on SPECT discusses attenuation correction and scatter correction. Preclinical studies investigated uptake of 90 Y-BrE-3 in mice using autoradiography. Clinical studies discuss image quantitation verses counts from biopsy samples, S factors for radiation dose calculation, 67 Cu imaging studies for lymphoma cancer, and 111 In MoAb imaging studies for breast cancer to predict 90 Y MoAb therapy

Transparency in the reporting of in vivo pre-clinical pain research: The relevance and implications of the ARRIVE (Animal Research: Reporting In Vivo Experiments) guidelines.

Science.gov (United States)

Rice, Andrew S C; Morland, Rosemary; Huang, Wenlong; Currie, Gillian L; Sena, Emily S; Macleod, Malcolm R

2017-12-29

Clear reporting of research is crucial to the scientific process. Poorly designed and reported studies are damaging not only to the efforts of individual researchers, but also to science as a whole. Standardised reporting methods, such as those already established for reporting randomised clinical trials, have led to improved study design and facilitated the processes of clinical systematic review and meta-analysis. Such standards were lacking in the pre-clinical field until the development of the ARRIVE (Animal Research: Reporting In Vivo Experiments) guidelines. These were prompted following a survey which highlighted a widespread lack of robust and consistent reporting of pre-clinical in vivo research, with reports frequently omitting basic information required for study replication and quality assessment. The resulting twenty item checklist in ARRIVE covers all aspects of experimental design with particular emphasis on bias reduction and methodological transparency. Influential publishers and research funders have already adopted ARRIVE. Further dissemination and acknowledgement of the importance of these guidelines is vital to their widespread implementation. Conclusions and implications Wide implementation of the ARRIVE guidelines for reporting of in vivo preclinical research, especially pain research, are essential for a much needed increased transparency and quality in publishing such research. ARRIVE will also positively influence improvements in experimental design and quality, assist the conduct of accurate replication studies of important new findings and facilitate meta-analyses of preclinical research.

Use of multimodality imaging and artificial intelligence for diagnosis and prognosis of early stages of Alzheimer's disease.

Science.gov (United States)

Liu, Xiaonan; Chen, Kewei; Wu, Teresa; Weidman, David; Lure, Fleming; Li, Jing

2018-04-01

Alzheimer's disease (AD) is a major neurodegenerative disease and the most common cause of dementia. Currently, no treatment exists to slow down or stop the progression of AD. There is converging belief that disease-modifying treatments should focus on early stages of the disease, that is, the mild cognitive impairment (MCI) and preclinical stages. Making a diagnosis of AD and offering a prognosis (likelihood of converting to AD) at these early stages are challenging tasks but possible with the help of multimodality imaging, such as magnetic resonance imaging (MRI), fluorodeoxyglucose (FDG)-positron emission topography (PET), amyloid-PET, and recently introduced tau-PET, which provides different but complementary information. This article is a focused review of existing research in the recent decade that used statistical machine learning and artificial intelligence methods to perform quantitative analysis of multimodality image data for diagnosis and prognosis of AD at the MCI or preclinical stages. We review the existing work in 3 subareas: diagnosis, prognosis, and methods for handling modality-wise missing data-a commonly encountered problem when using multimodality imaging for prediction or classification. Factors contributing to missing data include lack of imaging equipment, cost, difficulty of obtaining patient consent, and patient drop-off (in longitudinal studies). Finally, we summarize our major findings and provide some recommendations for potential future research directions. Copyright © 2018 Elsevier Inc. All rights reserved.

Clinical study on postoperative steroid hormon replacement for preclinical Cushing's syndrome

International Nuclear Information System (INIS)

Furuta, Nozomu; Koide, Haruhisa; Sasaki, Hiroshi; Miki, Jun; Kimura, Takahiro; Egawa, Shin

2009-01-01

Diagnostic criteria for preclinical Cushing's syndrome (PCS) were reported in 1996. However, requirement of postoperative steroid hormone replacement is still controversial issue. In this study, we observed recent surgical cases retrospectively and evaluate the use of postoperative steroid hormone replacement. Eighteen patients with PCS underwent surgery from 1997 to 2007 in Jikei University Hospital. Thirteen of them received postoperative steroid hormone replacement. We investigated preoperative hormone activity by 131 I-adosterol scintigraphy and suppression of adrenocorticotropic hormone (ACTH) and evaluated the requirement of postoperative steroid hormone replacement. Preoperative serum cortisol was normal range in all patients. Serum ACTH was suppressed in 10 of them (56%). In 131 I-adosterol scintigraphy, accumulation in ipsilateral side was observed in all patients. Accumulation in contralateral side was observed in 13 patients whose serum ACTH had tendency to be suppressed. Mean period of steroid hormone replacement was 19.8 weeks. Patients with lower preoperative ACTH tended to require longer period until withdrawal of steroid hormone replacement. In addition, patients received steroid hormone replacement with higher starting dose significantly required longer period. Three of them had complications during tapering of steroid hormone. Postoperative adrenal insufficiency is important issue as postoperative management of PCS patients whose function of contralateral adrenal or pituitary gland is suppressed. 131 I-adosterol scintigraphy and preoperative serum ACTH were important factors to evaluate the requirement of postoperative steroid hormone replacement. Especially, patients with low preoperative serum ACTH tended to require long duration of postoperative steroid hormone replacement. On the other hand, patients with accumulation of contralateral side in 131 I-adosterol scintigraphy and without suppression of serum ACTH may not require steroid hormone

Pre-clinical MR elastography: Principles, techniques, and applications

Science.gov (United States)

Bayly, P. V.; Garbow, J. R.

2018-06-01

Magnetic resonance elastography (MRE) is a method for measuring the mechanical properties of soft tissue in vivo, non-invasively, by imaging propagating shear waves in the tissue. The speed and attenuation of waves depends on the elastic and dissipative properties of the underlying material. Tissue mechanical properties are essential for biomechanical models and simulations, and may serve as markers of disease, injury, development, or recovery. MRE is already established as a clinical technique for detecting and characterizing liver disease. The potential of MRE for diagnosing or characterizing disease in other organs, including brain, breast, and heart is an active research area. Studies involving MRE in the pre-clinical setting, in phantoms and artificial biomaterials, in the mouse, and in other mammals, are critical to the development of MRE as a robust, reliable, and useful modality.

Antitumor effects of regorafenib and sorafenib in preclinical models of hepatocellular carcinoma

OpenAIRE

Kissel, Maria; Berndt, Sandra; Fiebig, Lukas; Kling, Simon; Ji, Qunsheng; Gu, Qingyang; Lang, Tina; Hafner, Frank-Thorsten; Teufel, Michael; Zopf, Dieter

2017-01-01

The purpose of this study was to investigate the antitumor activity of regorafenib and sorafenib in preclinical models of HCC and to assess their mechanism of action by associated changes in protein expression in a HCC-PDX mouse model. Both drugs were administered orally once daily at 10 mg/kg (regorafenib) or 30 mg/kg (sorafenib), which recapitulate the human exposure at the maximally tolerated dose in mice. In a H129 hepatoma model, survival times differed significantly between regorafenib ...

Cardiac safety implications of hNav1.5 blockade and a framework for preclinical evaluation

Directory of Open Access Journals (Sweden)

Gul eErdemli

2012-01-01

Full Text Available The human cardiac sodium channel (hNav1.5, encoded by the SCN5A gene is critical for action potential generation and propagation in the heart. Drug-induced sodium channel inhibition decreases the rate of cardiomyocyte depolarization and consequently conduction velocity and can have serious implications for cardiac safety. Genetic mutations in hNav1.5 have also been linked to a number of cardiac diseases. Therefore, off-target hNav1.5 inhibition may be considered a risk marker for a drug candidate. Given the potential safety implications for patients and the costs of late stage drug development, detection and mitigation of hNav1.5 liabilities early in drug discovery and development becomes important. In this review, we describe a preclinical strategy to identify hNav1.5 liabilities that incorporates in vitro, in vivo, and in silico techniques and the application of this information in the integrated risk assessment at different stages of drug discovery and development.

Assessment of preclinical students' academic motivation before and after a three-day academic affair program.

Science.gov (United States)

Aung, Myo Nyein; Somboonwong, Juraiporn; Jaroonvanichkul, Vorapol; Wannakrairot, Pongsak

2015-01-01

Medical students' motivation is an important driving factor for academic performance, and therefore medical teachers and educators are often highly interested in this topic. This study evaluated the impact of an academic affair program upon preclinical year medical students' motivation to study. An intervention study was conducted using a pretest-posttest study design. A total of 296 preclinical year medical students who had just passed their first year and were about to attend their second year at the Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, participated in the study. The intervention comprised of dialogues for personality development, pictorial expression in groups, as well as small group lectures delivered by senior students giving information on how to prepare for the forthcoming classes. Students' academic motivation was measured before and after the intervention program, applying the transculturally translated Academic Motivation Scale (AMS). Cronbach's alpha of Thai version AMS was 0.8992. The average scores in seven scales of AMS were compared between the pre- and posttest results, using the Wilcoxon signed-rank test. The differences were confirmed by using the multivariate analysis of variance. Students' academic motivation increased after participation in the three-day academic program. There was also a significant increase in introjected extrinsic motivation, which can enhance the students' self-esteem and feeling of self-worth (Pmotivation toward accomplishment increased significantly (Pacademic milestones, and a step ahead of autonomous motivation. Amotivation level declined significantly (Pacademic motivational constructs before and after the intervention was altogether significant (P=0.036, multivariate analysis of variance). After experiencing a three-day intervention, the new students' motivation advanced along the continuum of self-determination toward autonomous motivation. Therefore, it is considered to be worthwhile

Assessment of preclinical students’ academic motivation before and after a three-day academic affair program

Science.gov (United States)

Aung, Myo Nyein; Somboonwong, Juraiporn; Jaroonvanichkul, Vorapol; Wannakrairot, Pongsak

2015-01-01

Background Medical students’ motivation is an important driving factor for academic performance, and therefore medical teachers and educators are often highly interested in this topic. This study evaluated the impact of an academic affair program upon preclinical year medical students’ motivation to study. Design and methods An intervention study was conducted using a pretest-posttest study design. A total of 296 preclinical year medical students who had just passed their first year and were about to attend their second year at the Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, participated in the study. The intervention comprised of dialogues for personality development, pictorial expression in groups, as well as small group lectures delivered by senior students giving information on how to prepare for the forthcoming classes. Students’ academic motivation was measured before and after the intervention program, applying the transculturally translated Academic Motivation Scale (AMS). Cronbach’s alpha of Thai version AMS was 0.8992. The average scores in seven scales of AMS were compared between the pre- and posttest results, using the Wilcoxon signed-rank test. The differences were confirmed by using the multivariate analysis of variance. Results Students’ academic motivation increased after participation in the three-day academic program. There was also a significant increase in introjected extrinsic motivation, which can enhance the students’ self-esteem and feeling of self-worth (PAmotivation level declined significantly (P<0.001). The change of academic motivational constructs before and after the intervention was altogether significant (P=0.036, multivariate analysis of variance). Conclusion After experiencing a three-day intervention, the new students’ motivation advanced along the continuum of self-determination toward autonomous motivation. Therefore, it is considered to be worthwhile conducting an academic intervention to

Quetiapine: recent developments in preclinical research

Directory of Open Access Journals (Sweden)

Marco Orsetti

2010-03-01

Full Text Available Quetiapine (QTP is an atypical antipsychotic labelled for the treatment of patients with schizophrenia, bipolar mania and bipolar depression. Nevertheless, QTP has been tried across multiple diagnosis categories and seems to be used, among other atypical antipsychotics, in clinical practice for an expanding range of disorders such as major depression, substance abuse disorders, anxiety disorders, and borderline personality disorders. The present review focuses on papers which investigated the molecular mechanism(s of QTP antidepressant effect. In particular, preclinical studies performed by coupling the chronic mild stress, an animal model of human depression with Affymetrix microarray technology, revealed that chronic QTP administration prevented the stress-induced up- or down-regulation of 42 genes involved in the central nervous system development or having a crucial role for viability of neural cells, like regulation of signal transduction, inorganic ion transport, membrane organisation, and neurite morphogenesis. Among these, Ptgs2, Hes5, Plcb1, Senp2, Gad1, and Marcks are presumably the effectors of the QTP clinical efficacy.

Preclinical Assessment of a Strategy to Minimize the Abuse Liability of Opiate Medications for Pain

Science.gov (United States)

2016-09-01

plans (3). In fact, Bray and colleagues found that pain medication is the most highly abused of all prescribed drugs in the military (4). Prescription...the drug gamma-vinyl GABA (GVG) prior to morphine treatment effectively eliminates the highly addictive nature of this opiate . In these studies, we...widespread risk of opiate addiction in this population. Preclinical imaging studies aim to build a foundation for effective clinical drug development, and the

Use of a clinical PET/MR scanner for preclinical research with first results

International Nuclear Information System (INIS)

Chary, Karthik; Teuho, Jarmo; Virta, Jenni; Sipilä, Hannu; Saunavaara, Virva; Roivainen, Anne; Teräs, Mika

2014-01-01

This study was performed to evaluate the feasibility of preclinical imaging in a clinical PET/MR system. Preliminary sequences were evaluated for establishing preclinical protocols for rat brain and rabbit knee. Rats were placed in a stereotactic holder, allowing a 30 minute scan time before re-administration of anesthesia. In-house developed warm-water heating system was used to maintain the body temperature at 37.5°C, monitored using an MR-compatible rectal probe. Brain imaging was performed with a dedicated 4 channel phased array receive coil (RAPID Biomedical GmbH, Germany). High resolution coronal images were acquired using conventional T1-SE (0.30x0.30x1.2mm) and T2-TSE (0.23x0.23x0.7mm) with a total scan time of 30 min. PET/MR imaging was performed on two white rabbits. The rabbits were imaged in a custom wooden holder. PET/MR protocol had a total duration of 45 minutes. No external heating was used. MR protocol consisted of anatomical T1, T2 and PDW of the knees, using a SENSE Flex-S coil. MR attenuation correction (MRAC) was acquired with 3D T1-FFE using three-class segmentation. A dynamic 30 minute PET acquisition was started on injection of 33.8MBq of Ga-68. Animal coils enabled high resolution images to be acquired in reasonable acquisition time with regards to animal handling and anesthesia. T1 and T2 images provided good differentiation of anatomy in the rat brain with high contrast. T1, T2 and PDW images of the rabbit knee had high resolution and differentiation of anatomical structures. MRAC was able to distinguish the knees and the body contour. Image fusion of PET and MR was able to localize the infection, which was confirmed by a physician. Pre-clinical imaging with the Ingenuity TF was deemed feasible, although PET imaging is limited by the resolution of the scanner. The preliminary sequences were successfully implemented for future studies on the Ingenuity TF.

Use of a clinical PET/MR scanner for preclinical research with first results

Energy Technology Data Exchange (ETDEWEB)

Chary, Karthik; Teuho, Jarmo; Virta, Jenni; Sipilä, Hannu; Saunavaara, Virva; Roivainen, Anne; Teräs, Mika [Turku PET Centre, Turku University Hospital, Turku (Finland)

2014-07-29

This study was performed to evaluate the feasibility of preclinical imaging in a clinical PET/MR system. Preliminary sequences were evaluated for establishing preclinical protocols for rat brain and rabbit knee. Rats were placed in a stereotactic holder, allowing a 30 minute scan time before re-administration of anesthesia. In-house developed warm-water heating system was used to maintain the body temperature at 37.5°C, monitored using an MR-compatible rectal probe. Brain imaging was performed with a dedicated 4 channel phased array receive coil (RAPID Biomedical GmbH, Germany). High resolution coronal images were acquired using conventional T1-SE (0.30x0.30x1.2mm) and T2-TSE (0.23x0.23x0.7mm) with a total scan time of 30 min. PET/MR imaging was performed on two white rabbits. The rabbits were imaged in a custom wooden holder. PET/MR protocol had a total duration of 45 minutes. No external heating was used. MR protocol consisted of anatomical T1, T2 and PDW of the knees, using a SENSE Flex-S coil. MR attenuation correction (MRAC) was acquired with 3D T1-FFE using three-class segmentation. A dynamic 30 minute PET acquisition was started on injection of 33.8MBq of Ga-68. Animal coils enabled high resolution images to be acquired in reasonable acquisition time with regards to animal handling and anesthesia. T1 and T2 images provided good differentiation of anatomy in the rat brain with high contrast. T1, T2 and PDW images of the rabbit knee had high resolution and differentiation of anatomical structures. MRAC was able to distinguish the knees and the body contour. Image fusion of PET and MR was able to localize the infection, which was confirmed by a physician. Pre-clinical imaging with the Ingenuity TF was deemed feasible, although PET imaging is limited by the resolution of the scanner. The preliminary sequences were successfully implemented for future studies on the Ingenuity TF.

The interplay of early-life stress, nutrition, and immune activation programs adult hippocampal structure and function

Science.gov (United States)

Hoeijmakers, Lianne; Lucassen, Paul J.; Korosi, Aniko

2015-01-01

Early-life adversity increases the vulnerability to develop psychopathologies and cognitive decline later in life. This association is supported by clinical and preclinical studies. Remarkably, experiences of stress during this sensitive period, in the form of abuse or neglect but also early malnutrition or an early immune challenge elicit very similar long-term effects on brain structure and function. During early-life, both exogenous factors like nutrition and maternal care, as well as endogenous modulators, including stress hormones and mediator of immunological activity affect brain development. The interplay of these key elements and their underlying molecular mechanisms are not fully understood. We discuss here the hypothesis that exposure to early-life adversity (specifically stress, under/malnutrition and infection) leads to life-long alterations in hippocampal-related cognitive functions, at least partly via changes in hippocampal neurogenesis. We further discuss how these different key elements of the early-life environment interact and affect one another and suggest that it is a synergistic action of these elements that shapes cognition throughout life. Finally, we consider different intervention studies aiming to prevent these early-life adversity induced consequences. The emerging evidence for the intriguing interplay of stress, nutrition, and immune activity in the early-life programming calls for a more in depth understanding of the interaction of these elements and the underlying mechanisms. This knowledge will help to develop intervention strategies that will converge on a more complete set of changes induced by early-life adversity. PMID:25620909

Pre-clinical studies of toxin-specific Nanobodies: Evidence of in vivo efficacy to prevent fatal disturbances provoked by scorpion envenoming

International Nuclear Information System (INIS)

Hmila, Issam; Cosyns, Bernard; Tounsi, Hayfa; Roosens, Bram; Caveliers, Vicky; Abderrazek, Rahma Ben; Boubaker, Samir; Muyldermans, Serge; El Ayeb, Mohamed; Bouhaouala-Zahar, Balkiss; Lahoutte, Tony

2012-01-01

Scorpions represent a significant threat to humans and animals in various countries throughout the world. Recently, we introduced Nanobodies (Nbs) to combat more efficiently scorpion envenoming and demonstrated the performance of NbAahIF12 and NbAahII10 to neutralize scorpion toxins of Androctonus australis hector venom. A bispecific Nb construct (NbF12-10) comprising these two Nbs is far more protective than the classic Fab′ 2 based therapy and is the most efficient antivenom therapy against scorpion sting in preclinical studies. Now we investigate the biodistribution and pharmacokinetics of 99m Tc labeled Nbs by in vivo imaging in rodents and compared these data with those of the Fab′ 2 product (PAS). The pharmacodynamics of the Nbs was investigated in rats by in vivo echocardiography and it is shown that NbF12-10 prevents effectively the hemodynamic disturbances induced by a lethal dose of venom. Moreover, even a late injection of NbF12-10 restores the heart rate and brings the blood pressure to baseline values. Histology confirms that NbF12-10 prevents lung and heart lesions of treated mice after envenoming. In conjunction, in this preclinical study, we provide proof of concept that NbF12-10 prevents effectively the fatal disturbances induced by Androctonus venom, and that the Nanobody based therapeutic has a potential to substitute the classic Fab′ 2 based product as immunotherapeutic in scorpion envenoming. Further clinical study using larger cohorts of animals should be considered to confirm the full protecting potential of our NbF12-10. -- Highlights: ► Nanobody therapy prevents the hemodynamic disturbances induced by a lethal dose. ► Late injection of Nanobody restores hemodynamic parameters to baseline values. ► Nanobody therapy prevents lung and heart lesions of treated mice after envenoming. ► Labeled Nanobody and Fab’2 pharmacokinetics curves reach plateau in favour of Nanobody.

Pre-clinical studies of toxin-specific Nanobodies: Evidence of in vivo efficacy to prevent fatal disturbances provoked by scorpion envenoming

Energy Technology Data Exchange (ETDEWEB)

Hmila, Issam [Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, 13 Place Pasteur, BP-74, 1002 Tunis (Tunisia); Cosyns, Bernard [Laboratory of In Vivo Cellular and Molecular Imaging, Vrije Universiteit Brussel (Belgium); Tounsi, Hayfa [Service d' Anatomo-Pathologie, Institut Pasteur de Tunis, 13 Place Pasteur, BP-74, 1002 Tunis (Tunisia); Roosens, Bram; Caveliers, Vicky [Laboratory of In Vivo Cellular and Molecular Imaging, Vrije Universiteit Brussel (Belgium); Abderrazek, Rahma Ben [Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, 13 Place Pasteur, BP-74, 1002 Tunis (Tunisia); Boubaker, Samir [Service d' Anatomo-Pathologie, Institut Pasteur de Tunis, 13 Place Pasteur, BP-74, 1002 Tunis (Tunisia); Muyldermans, Serge [Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel (Belgium); Department of Structural Biology, VIB, Brussels (Belgium); El Ayeb, Mohamed [Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, 13 Place Pasteur, BP-74, 1002 Tunis (Tunisia); Bouhaouala-Zahar, Balkiss, E-mail: balkiss.bouhaouala@pasteur.rns.tn [Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, 13 Place Pasteur, BP-74, 1002 Tunis (Tunisia); Faculté de Médecine de Tunis, Université de Tunis-El Manar (Tunisia); Lahoutte, Tony [Laboratory of In Vivo Cellular and Molecular Imaging, Vrije Universiteit Brussel (Belgium)

2012-10-15

Scorpions represent a significant threat to humans and animals in various countries throughout the world. Recently, we introduced Nanobodies (Nbs) to combat more efficiently scorpion envenoming and demonstrated the performance of NbAahIF12 and NbAahII10 to neutralize scorpion toxins of Androctonus australis hector venom. A bispecific Nb construct (NbF12-10) comprising these two Nbs is far more protective than the classic Fab′{sub 2} based therapy and is the most efficient antivenom therapy against scorpion sting in preclinical studies. Now we investigate the biodistribution and pharmacokinetics of {sup 99m}Tc labeled Nbs by in vivo imaging in rodents and compared these data with those of the Fab′{sub 2} product (PAS). The pharmacodynamics of the Nbs was investigated in rats by in vivo echocardiography and it is shown that NbF12-10 prevents effectively the hemodynamic disturbances induced by a lethal dose of venom. Moreover, even a late injection of NbF12-10 restores the heart rate and brings the blood pressure to baseline values. Histology confirms that NbF12-10 prevents lung and heart lesions of treated mice after envenoming. In conjunction, in this preclinical study, we provide proof of concept that NbF12-10 prevents effectively the fatal disturbances induced by Androctonus venom, and that the Nanobody based therapeutic has a potential to substitute the classic Fab′{sub 2} based product as immunotherapeutic in scorpion envenoming. Further clinical study using larger cohorts of animals should be considered to confirm the full protecting potential of our NbF12-10. -- Highlights: ► Nanobody therapy prevents the hemodynamic disturbances induced by a lethal dose. ► Late injection of Nanobody restores hemodynamic parameters to baseline values. ► Nanobody therapy prevents lung and heart lesions of treated mice after envenoming. ► Labeled Nanobody and Fab’2 pharmacokinetics curves reach plateau in favour of Nanobody.

Facilitating healthcare decisions by assessing the certainty in the evidence from preclinical animal studies

Science.gov (United States)

Hooijmans, Carlijn R.; de Vries, Rob B. M.; Ritskes-Hoitinga, Merel; Rovers, Maroeska M.; Leeflang, Mariska M.; IntHout, Joanna; Wever, Kimberley E.; Hooft, Lotty; de Beer, Hans; Kuijpers, Ton; Macleod, Malcolm R.; Sena, Emily S.; ter Riet, Gerben; Morgan, Rebecca L.; Thayer, Kristina A.; Rooney, Andrew A.; Guyatt, Gordon H.; Schünemann, Holger J.

2018-01-01

Laboratory animal studies are used in a wide range of human health related research areas, such as basic biomedical research, drug research, experimental surgery and environmental health. The results of these studies can be used to inform decisions regarding clinical research in humans, for example the decision to proceed to clinical trials. If the research question relates to potential harms with no expectation of benefit (e.g., toxicology), studies in experimental animals may provide the only relevant or controlled data and directly inform clinical management decisions. Systematic reviews and meta-analyses are important tools to provide robust and informative evidence summaries of these animal studies. Rating how certain we are about the evidence could provide important information about the translational probability of findings in experimental animal studies to clinical practice and probably improve it. Evidence summaries and certainty in the evidence ratings could also be used (1) to support selection of interventions with best therapeutic potential to be tested in clinical trials, (2) to justify a regulatory decision limiting human exposure (to drug or toxin), or to (3) support decisions on the utility of further animal experiments. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach is the most widely used framework to rate the certainty in the evidence and strength of health care recommendations. Here we present how the GRADE approach could be used to rate the certainty in the evidence of preclinical animal studies in the context of therapeutic interventions. We also discuss the methodological challenges that we identified, and for which further work is needed. Examples are defining the importance of consistency within and across animal species and using GRADE’s indirectness domain as a tool to predict translation from animal models to humans. PMID:29324741

Facilitating healthcare decisions by assessing the certainty in the evidence from preclinical animal studies.

Science.gov (United States)

Hooijmans, Carlijn R; de Vries, Rob B M; Ritskes-Hoitinga, Merel; Rovers, Maroeska M; Leeflang, Mariska M; IntHout, Joanna; Wever, Kimberley E; Hooft, Lotty; de Beer, Hans; Kuijpers, Ton; Macleod, Malcolm R; Sena, Emily S; Ter Riet, Gerben; Morgan, Rebecca L; Thayer, Kristina A; Rooney, Andrew A; Guyatt, Gordon H; Schünemann, Holger J; Langendam, Miranda W

2018-01-01

Laboratory animal studies are used in a wide range of human health related research areas, such as basic biomedical research, drug research, experimental surgery and environmental health. The results of these studies can be used to inform decisions regarding clinical research in humans, for example the decision to proceed to clinical trials. If the research question relates to potential harms with no expectation of benefit (e.g., toxicology), studies in experimental animals may provide the only relevant or controlled data and directly inform clinical management decisions. Systematic reviews and meta-analyses are important tools to provide robust and informative evidence summaries of these animal studies. Rating how certain we are about the evidence could provide important information about the translational probability of findings in experimental animal studies to clinical practice and probably improve it. Evidence summaries and certainty in the evidence ratings could also be used (1) to support selection of interventions with best therapeutic potential to be tested in clinical trials, (2) to justify a regulatory decision limiting human exposure (to drug or toxin), or to (3) support decisions on the utility of further animal experiments. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach is the most widely used framework to rate the certainty in the evidence and strength of health care recommendations. Here we present how the GRADE approach could be used to rate the certainty in the evidence of preclinical animal studies in the context of therapeutic interventions. We also discuss the methodological challenges that we identified, and for which further work is needed. Examples are defining the importance of consistency within and across animal species and using GRADE's indirectness domain as a tool to predict translation from animal models to humans.

Disclosure of amyloid status is not a barrier to recruitment in preclinical Alzheimer’s disease clinical trials

Science.gov (United States)

Grill, Joshua; Zhou, Yan; Elashoff, David; Karlawish, Jason

2016-01-01

Preclinical Alzheimer’s disease (AD) clinical trials may require participants to learn if they meet biomarker enrollment criteria to enroll. To examine whether this requirement will impact trial recruitment, we presented 132 older community volunteers who self-reported normal cognition with one of two hypothetical informed consent forms (ICF) describing an AD prevention clinical trial. Both ICFs described amyloid Positron Emission Tomography (PET) scans. One ICF stated that scan results would not be shared with the participants (blinded enrollment); the other stated that only persons with elevated amyloid would be eligible (transparent enrollment). Participants rated their likelihood of enrollment and completed an interview with a research assistant. We found no difference between the groups in willingness to participate. Study risks and the requirement of a study partner were reported as the most important factors in the decision whether to enroll. The requirement of biomarker disclosure may not slow recruitment to preclinical AD trials. PMID:26923411

Advantages of Papio anubis for preclinical testing of immunotoxicity of candidate therapeutic antagonist antibodies targeting CD28

Science.gov (United States)

Poirier, Nicolas; Mary, Caroline; Le Bas-Bernardet, Stephanie; Daguin, Veronique; Belarif, Lyssia; Chevalier, Melanie; Hervouet, Jeremy; Minault, David; Ville, Simon; Charpy, Vianney; Blancho, Gilles; Vanhove, Bernard

2014-01-01

Antagonist anti-CD28 antibodies prevent T-cell costimulation and are functionally different from CTLA4Ig since they cannot block CTLA-4 and PDL-1 co-inhibitory signals. They demonstrated preclinical efficacy in suppressing effector T cells while enhancing immunoregulatory mechanisms. Because a severe cytokine release syndrome was observed during the Phase 1 study with the superagonist anti-CD28 TGN1412, development of other anti-CD28 antibodies requires careful preclinical evaluation to exclude any potential immunotoxicity side-effects. The failure to identify immunological toxicity of TGN1412 using macaques led us to investigate more relevant preclinical models. We report here that contrary to macaques, and like in man, all baboon CD4-positive T lymphocytes express CD28 in their effector memory cells compartment, a lymphocyte subtype that is the most prone to releasing cytokines after reactivation. Baboon lymphocytes are able to release pro-inflammatory cytokines in vitro in response to agonist or superagonist anti-CD28 antibodies. Furthermore, we compared the reactivity of human and baboon lymphocytes after transfer into non obese diabetic/severe combined immunodeficiency (NOD/SCID) interleukin-2rγ knockout mice and confirmed that both cell types could release inflammatory cytokines in situ after injection of agonistic anti-CD28 antibodies. In contrast, FR104, a monovalent antagonistic anti-CD28 antibody, did not elicit T cell activation in these assays, even in the presence of anti-drug antibodies. Infusion to baboons also resulted in an absence of cytokine release. In conclusion, the baboon represents a suitable species for preclinical immunotoxicity evaluation of anti-CD28 antibodies because their effector memory T cells do express CD28 and because cytokine release can be assessed in vitro and trans vivo. PMID:24598534

Treatment of TBI with Hormonal and Pharmacological Support, Preclinical Validation Using Diffuse and Mechanical TBI Animal Models

Science.gov (United States)

2016-05-01

Award Number: PT075653 (grant) W81XWH-08-2-0153 (contract) TITLE: Treatment of TBI with Hormonal and Pharmacological Support, Preclinical...TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-08-2-0153 Treatment of TBI with Hormonal and Pharmacological Support, Preclinical Validation Using...rats. Our in vivo tests also included MRI imaging, focusing on edema resolution and reduction of diffuse axonal damage (fractional anisotropy

Novel epigenetic target therapy for prostate cancer: a preclinical study.

Directory of Open Access Journals (Sweden)

Ilaria Naldi

Full Text Available Epigenetic events are critical contributors to the pathogenesis of cancer, and targeting epigenetic mechanisms represents a novel strategy in anticancer therapy. Classic demethylating agents, such as 5-Aza-2'-deoxycytidine (Decitabine, hold the potential for reprograming somatic cancer cells demonstrating high therapeutic efficacy in haematological malignancies. On the other hand, epigenetic treatment of solid tumours often gives rise to undesired cytotoxic side effects. Appropriate delivery systems able to enrich Decitabine at the site of action and improve its bioavailability would reduce the incidence of toxicity on healthy tissues. In this work we provide preclinical evidences of a safe, versatile and efficient targeted epigenetic therapy to treat hormone sensitive (LNCap and hormone refractory (DU145 prostate cancers. A novel Decitabine formulation, based on the use of engineered erythrocyte (Erythro-Magneto-Hemagglutinin Virosomes, EMHVs drug delivery system (DDS carrying this drug, has been refined. Inside the EMHVs, the drug was shielded from the environment and phosphorylated in its active form. The novel magnetic EMHV DDS, endowed with fusogenic protein, improved the stability of the carried drug and exhibited a high efficiency in confining its delivery at the site of action in vivo by applying an external static magnetic field. Here we show that Decitabine loaded into EMHVs induces a significant tumour mass reduction in prostate cancer xenograft models at a concentration, which is seven hundred times lower than the therapeutic dose, suggesting an improved pharmacokinetics/pharmacodynamics of drug. These results are relevant for and discussed in light of developing personalised autologous therapies and innovative clinical approach for the treatment of solid tumours.

Novel epigenetic target therapy for prostate cancer: a preclinical study.

Science.gov (United States)

Naldi, Ilaria; Taranta, Monia; Gherardini, Lisa; Pelosi, Gualtiero; Viglione, Federica; Grimaldi, Settimio; Pani, Luca; Cinti, Caterina

2014-01-01

Epigenetic events are critical contributors to the pathogenesis of cancer, and targeting epigenetic mechanisms represents a novel strategy in anticancer therapy. Classic demethylating agents, such as 5-Aza-2'-deoxycytidine (Decitabine), hold the potential for reprograming somatic cancer cells demonstrating high therapeutic efficacy in haematological malignancies. On the other hand, epigenetic treatment of solid tumours often gives rise to undesired cytotoxic side effects. Appropriate delivery systems able to enrich Decitabine at the site of action and improve its bioavailability would reduce the incidence of toxicity on healthy tissues. In this work we provide preclinical evidences of a safe, versatile and efficient targeted epigenetic therapy to treat hormone sensitive (LNCap) and hormone refractory (DU145) prostate cancers. A novel Decitabine formulation, based on the use of engineered erythrocyte (Erythro-Magneto-Hemagglutinin Virosomes, EMHVs) drug delivery system (DDS) carrying this drug, has been refined. Inside the EMHVs, the drug was shielded from the environment and phosphorylated in its active form. The novel magnetic EMHV DDS, endowed with fusogenic protein, improved the stability of the carried drug and exhibited a high efficiency in confining its delivery at the site of action in vivo by applying an external static magnetic field. Here we show that Decitabine loaded into EMHVs induces a significant tumour mass reduction in prostate cancer xenograft models at a concentration, which is seven hundred times lower than the therapeutic dose, suggesting an improved pharmacokinetics/pharmacodynamics of drug. These results are relevant for and discussed in light of developing personalised autologous therapies and innovative clinical approach for the treatment of solid tumours.

Preclinical activity of selinexor, an inhibitor of XPO1, in sarcoma.

Science.gov (United States)

Nakayama, Robert; Zhang, Yi-Xiang; Czaplinski, Jeffrey T; Anatone, Alex J; Sicinska, Ewa T; Fletcher, Jonathan A; Demetri, George D; Wagner, Andrew J

2016-03-29

Selinexor is an orally bioavailable selective inhibitor of nuclear export that has been demonstrated to have preclinical activity in various cancer types and that is currently in Phase I and II clinical trials for advanced cancers. In this study, we evaluated the effects of selinexor in several preclinical models of various sarcoma subtypes. The efficacy of selinexor was investigated in vitro and in vivo using 17 cell lines and 9 sarcoma xenograft models including gastrointestinal stromal tumor (GIST), liposarcoma (LPS), leiomyosarcoma, rhabdomyosarcoma, undifferentiated sarcomas, and alveolar soft part sarcoma (ASPS). Most sarcoma cell lines were sensitive to selinexor with IC50s ranging from 28.8 nM to 218.2 nM (median: 66.1 nM). Selinexor suppressed sarcoma tumor xenograft growth, including models of ASPS that were resistant in vitro. In GIST cells with KIT mutations, selinexor induced G1- arrest without attenuation of phosphorylation of KIT, AKT, or MAPK, in contrast to imatinib. In LPS cell lines with MDM2 and CDK4 amplification, selinexor induced G1-arrest and apoptosis irrespective of p53 expression or mutation and irrespective of RB expression. Selinexor increased p53 and p21 expression at the protein but not RNA level, indicating a post-transcriptional effect. These results indicate that selinexor has potent in vitro and in vivo activity against a wide variety of sarcoma models by inducing G1-arrest independent of known molecular mechanisms in GIST and LPS. These studies further justify the exploration of selinexor in clinical trials targeting various sarcoma subtypes.

Annular phased array transducer for preclinical testing of anti-cancer drug efficacy on small animals.

Science.gov (United States)

Kujawska, Tamara; Secomski, Wojciech; Byra, Michał; Postema, Michiel; Nowicki, Andrzej

2017-04-01

A technique using pulsed High Intensity Focused Ultrasound (HIFU) to destroy deep-seated solid tumors is a promising noninvasive therapeutic approach. A main purpose of this study was to design and test a HIFU transducer suitable for preclinical studies of efficacy of tested, anti-cancer drugs, activated by HIFU beams, in the treatment of a variety of solid tumors implanted to various organs of small animals at the depth of the order of 1-2cm under the skin. To allow focusing of the beam, generated by such transducer, within treated tissue at different depths, a spherical, 2-MHz, 29-mm diameter annular phased array transducer was designed and built. To prove its potential for preclinical studies on small animals, multiple thermal lesions were induced in a pork loin ex vivo by heating beams of the same: 6W, or 12W, or 18W acoustic power and 25mm, 30mm, and 35mm focal lengths. Time delay for each annulus was controlled electronically to provide beam focusing within tissue at the depths of 10mm, 15mm, and 20mm. The exposure time required to induce local necrosis was determined at different depths using thermocouples. Location and extent of thermal lesions determined from numerical simulations were compared with those measured using ultrasound and magnetic resonance imaging techniques and verified by a digital caliper after cutting the tested tissue samples. Quantitative analysis of the results showed that the location and extent of necrotic lesions on the magnetic resonance images are consistent with those predicted numerically and measured by caliper. The edges of lesions were clearly outlined although on ultrasound images they were fuzzy. This allows to conclude that the use of the transducer designed offers an effective noninvasive tool not only to induce local necrotic lesions within treated tissue without damaging the surrounding tissue structures but also to test various chemotherapeutics activated by the HIFU beams in preclinical studies on small animals

Preclinical studies on toxicity, antitumour activity and pharmacokinetics of cisplatin and three recently developed derivatives.

Science.gov (United States)

Lelieveld, P; Van der Vijgh, W J; Veldhuizen, R W; Van Velzen, D; Van Putten, L M; Atassi, G; Danguy, A

1984-08-01

Preclinical studies were performed in mice, rats and dogs of cis-diamminedichloroplatinum(II) (CDDP) and its derivatives cis-1,1-di(aminomethyl) cyclohexane platinum(II) sulphate (TNO-6), cis-diammine-1,1-cyclobutanedicarboxylate platinum(II) (CBDCA) and cis-dichloro, trans-dihydroxybis-isopropylamine platinum(IV) (CHIP). In mice toxicity and antitumour activity were determined. All three derivatives were at least as toxic as CDDP for haemopoietic stem cells and were less active than CDDP against the mouse tumours leukaemia L1210 and osteosarcoma C22LR. Toxicology studies in rats revealed no renal toxicity after a single dose of TNO-6. Fractionated doses of TNO-6 and CBDCA did cause renal toxicity but less than CDDP. CHIP produced little or no kidney damage. In dogs, TNO-6 (1.5 mg/kg) produced more severe kidney damage--although this was reversible--than CDDP (2 mg/kg). Half-lives of distribution were 4.0-5.1 min for TNO-6 and 9.7 min for CDDP, while half-lives of elimination were 3.6-6.6 days and 5.9 days respectively. Plasma levels, normalized for the dose, were at least two times higher after TNO-6 than after CDDP. Twelve weeks after drug administration, plasma levels were undetectable, while tissue concentrations could still be measured. The platinum concentration in kidney cortex was higher after CDDP than after TNO-6.

Preclinical models of shock and sepsis: what can they tell us?

NARCIS (Netherlands)

Marshall, John C.; Deitch, Edwin; Moldawer, Lyle L.; Opal, Steven; Redl, Heinz; van der Poll, Tom

2005-01-01

The goal of translational research is to transform biologic knowledge into new treatments for human disease. Although preclinical models replicate some of the features of the disease process modeled, they invariably fail to reproduce the complexity of human illness, and by their very experimental

Six psychotropics for pre-symptomatic & early Alzheimer's (MCI, Parkinson's, and Huntington's disease modification

Directory of Open Access Journals (Sweden)

Edward C Lauterbach

2016-01-01

Full Text Available The quest for neuroprotective drugs to slow the progression of neurodegenerative diseases (NDDs, including Alzheimer's disease (AD, Parkinson's disease (PD, and Huntington's disease (HD, has been largely unrewarding. Preclinical evidence suggests that repurposing quetiapine, lithium, valproate, fluoxetine, donepezil, and memantine for early and pre-symptomatic disease-modification in NDDs may be promising and can spare regulatory barriers. The literature of these psychotropics in early stage and pre-symptomatic AD, PD, and HD is reviewed and propitious findings follow. Mild cognitive impairment (MCI phase of AD: salutary human randomized controlled trial findings for low-dose lithium and, in selected patients, donepezil await replication. Pre-symptomatic AD: human epidemiological data indicate that lithium reduces AD risk. Animal model studies (AMS reveal encouraging results for quetiapine, lithium, donepezil, and memantine. Early PD: valproate AMS findings show promise. Pre-symptomatic PD: lithium and valproate AMS findings are encouraging. Early HD: uncontrolled clinical data indicate non-progression with lithium, fluoxetine, donepezil, and memantine. Pre-symptomatic HD: lithium and valproate are auspicious in AMS. Many other promising findings awaiting replication (valproate in MCI; lithium, valproate, fluoxetine in pre-symptomatic AD; lithium in early PD; lithium, valproate, fluoxetine in pre-symptomatic PD; donepezil in early HD; lithium, fluoxetine, memantine in pre-symptomatic HD are reviewed. Dose- and stage-dependent effects are considered. Suggestions for signal-enhancement in human trials are provided for each NDD stage.

The Sheep as a Model of Preclinical Safety and Pharmacokinetic Evaluations of Candidate Microbicides

OpenAIRE

Holt, Jonathon D. S.; Cameron, David; Dias, Nicola; Holding, Jeremy; Muntendam, Alex; Oostebring, Freddy; Dreier, Peter; Rohan, Lisa; Nuttall, Jeremy

2015-01-01

When developing novel microbicide products for the prevention of HIV infection, the preclinical safety program must evaluate not only the active pharmaceutical ingredient but also the product itself. To that end, we applied several relatively standard toxicology study methodologies to female sheep, incorporating an assessment of the pharmacokinetics, safety, tolerability, and local toxicity of a dapivirine-containing human vaginal ring formulation (Dapivirine Vaginal Ring-004). We performed a...

Preclinical, clinical, and over-the-counter postmarketing experience with a new vaginal cup: menstrual collection.

Science.gov (United States)

North, Barbara B; Oldham, Michael J

2011-02-01

Menstrual cups have been available for decades, but their use is limited by bulky design and the need for multiple sizes. The Softcup® (Instead, Inc., San Diego, CA) is a simple single-size disposable over-the-counter (OTC) menstrual cup that compresses to tampon shape to facilitate insertion and can be worn during coitus. This report describes preclinical evaluation, clinical testing, and postmarketing monitoring of the Softcup. Preclinical testing complied with U.S. Food and Drug Administration (FDA) guidelines and used standard United States Pharmacopoeia methodologies for assessment of potential toxicity. Clinical testing enrolled 406 women in seven U.S. centers. A detailed written questionnaire assessed safety, acceptability, and effectiveness for menstrual collection. Study safety parameters included pelvic examinations, Pap smears, colposcopy, urinalysis, vaginal pH, wet mounts, gram stain, and vaginal microflora cultures. Postmarketing surveillance of over 100 million Softcups has been conducted by the manufacturer and by the FDA Medwatch system. No toxicity or mutagenicity was observed in preclinical evaluations. In clinical testing, after three cycles of cup use, 37% of subjects rated the cup as better than, 29% as worse than, and 34% as equal to pads or tampons. The cup was preferred for comfort, dryness, and less odor. Cups received lower ratings for disposal and convenience. Eighty-one percent of enrolled women were able to insert and remove their first cup using only written instructions. Use difficulties resulting in study discontinuations included cramping (1%), leakage (1%), and improper fit (3%). No safety parameters were adversely affected. No significant health risks were reported during postmarketing surveillance. These results demonstrate that a single-size vaginal device has no significant health risks and is acceptable to many women without the need for fitting or other medical services.

Post-SSRI Sexual Dysfunction: Preclinical to Clinical. Is It Fact or Fiction?

Science.gov (United States)

Coskuner, Enis Rauf; Culha, Mehmet Gokhan; Ozkan, Burak; Kaleagasi, Elcin Orhan

2018-04-01

Selective serotonin reuptake inhibitors (SSRIs) are a widely used class of drug for various psychiatric disorders during the lifespan, including pregnancy, lactation, childhood, and adolescence. Deterioration in sexual functioning is a major and serious adverse effect of SSRIs. There is emerging evidence that SSRIs can have long-lasting effects on sexuality. To summarize the long-lasting effects of SSRIs on sexuality, starting with animal models and continuing with the clinical experience of different investigators. A literature review of relevant publications in PubMed. To assess the long-lasting effects of SSRIs on sexuality. Although the persistent effects of SSRIs on sexuality have been little studied in humans, animal studies suggest that SSRIs might cause permanent sexual dysfunction after ending SSRI exposure at a young age but not in adulthood in rats. There are no prospective randomized controlled trials in humans and the present evidence is derived from case reports, incidental research findings, and experiences of some internet communities. There is some preclinical evidence from animal studies for enduring SSRI-induced sexual dysfunction, but the available clinical information could prevent a clear decision about the existence of post-SSRI sexual dysfunction, its pathophysiology, and its management. We need more research to fill in the gaps in our knowledge. Coskuner ER, Culha MG, Ozkan B, Kaleagasi EO. Post-SSRI Sexual Dysfunction: Preclinical to Clinical. Is It Fact or Fiction? Sex Med Rev 2018;6:217-223. Copyright © 2017 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Neratinib for the treatment of HER2-positive early stage breast cancer.

Science.gov (United States)

Echavarria, Isabel; López-Tarruella, Sara; Márquez-Rodas, Iván; Jerez, Yolanda; Martin, Miguel

2017-08-01

Despite the advances in the treatment of HER2-positive breast cancer, resistance to actual chemotherapeutic regimens eventually occurs. Neratinib, an orally available pan-inhibitor of the ERBB family, represents an interesting new option for early-stage HER2-positive breast cancer. Areas covered: In this article, the development of neratinib, with a special focus on its potential value in the treatment of early-stage HER2-positive breast cancer, has been reviewed. For this purpose, a literature search was conducted, including preclinical studies, early-phase trials in advanced cancer with neratinib in monotherapy and in combination, and phase II and large phase III trials in the early setting. Management of neratinib-induced toxicity, future perspectives for the drug, and ongoing trials are also discussed in this review. Expert commentary: Neratinib is emerging as a promising oral drug for the treatment of HER2-positive breast cancer. Although FDA and EMA approval is derived from the extended adjuvant treatment, this setting may not be the ideal scenario to obtain the beneficial effects of neratinib. Confirmatory data in the neoadjuvant setting and subgroup analysis from the ExTENET trial might bring some light into the best setting for neratinib therapy. Data from confirmatory trials in the metastatic setting are also required.

Targeted therapies for non-small-cell lung cancer: biology, rationale, and preclinical results from a radiation oncology perspective

International Nuclear Information System (INIS)

Raben, David; Helfrich, Barb; Bunn, Paul A.

2004-01-01

The epidermal growth factor receptor (EGFR) is overexpressed in the majority of non-small-cell lung cancers (NSCLCs). This presents an opportune target for new treatment strategies designed to selectively interfere with the cancer cell growth cycle. Recent investigations into the biology of the EGFR and its downstream signaling pathways have reminded us of the complexity of cancer cell communications from the cytoplasm to the nucleus. Multiple pathways are activated with stimulation of the autocrine and paracrine EGFR loop, from the ras-raf-MEK activation of ERK 1/2 to the P13K-Akt pathway, each playing an important role in cancer cell survival, invasion, and angiogenesis. Preclinical studies have demonstrated that molecules targeting the EGFR, either through extracellular blockade or intracellular interference with the EGFR-associated tyrosine kinase, reversibly or irreversibly, inhibit cancer cell growth. Potent antitumor effects have been observed in human tumor xenograft models. Preclinical studies have also demonstrated cooperative effects when anti-EGFR agents are combined with radiation or chemotherapy. Many of these agents have now entered into advanced human clinical trials with modest dose-related toxicity despite chronic administration. Encouraging response rates with single-agent targeted therapy have been reported in heavily pretreated patients with advanced NSCLC. In addition, agents targeting the angiogenic pathway, which plays a key role in the regulation of angiogenesis, may play an important role in enhancing the efficacy of anti-EGFR agents. This article will focus on the biology, rationale, and preclinical studies with targeted anti-EGFR and antiangiogenic therapies for the management of NSCLC

Pre-Clinical Testing of Real-Time PCR Assays for Diarrheal Disease Agents of Genera Escherichia and Shigella

Science.gov (United States)

2014-05-16

FOR DIARRHEAL DISEASE AGENTS OF GENERA ESCHERICHIA AND SHIGELLA May 16, 2014 Reporting Period: October 1, 2010 to September 30, 2013...10-2010 - 30-09-2013 PRE-CLINICAL TESTING OF REAL-TIME PCR ASSAYS FOR DIARRHEAL DISEASE AGENTS OF GENERA ESCHERICHIA AND SHIGELLA ...Texas (MOA 2007 - 2013. Agreement No.: DODI 4000.19; AFI 25-201). Pre-clinical test results qualify ETEC and Shigella real-time PCR assays as lead

Preclinical Testing of an Oncolytic Parvovirus: Standard Protoparvovirus H-1PV Efficiently Induces Osteosarcoma Cell Lysis In Vitro.

Science.gov (United States)

Geiss, Carsten; Kis, Zoltán; Leuchs, Barbara; Frank-Stöhr, Monika; Schlehofer, Jörg R; Rommelaere, Jean; Dinsart, Christiane; Lacroix, Jeannine

2017-10-17

Osteosarcoma is the most frequent malignant disease of the bone. On the basis of early clinical experience in the 1960s with H-1 protoparvovirus (H-1PV) in osteosarcoma patients, this effective oncolytic virus was selected for systematic preclinical testing on various osteosarcoma cell cultures. A panel of five human osteosarcoma cell lines (CAL 72, H-OS, MG-63, SaOS-2, U-2OS) was tested. Virus oncoselectivity was confirmed by infecting non-malignant human neonatal fibroblasts and osteoblasts used as culture models of non-transformed mesenchymal cells. H-1PV was found to enter osteosarcoma cells and to induce viral DNA replication, transcription of viral genes, and translation to viral proteins. After H-1PV infection, release of infectious viral particles from osteosarcoma cells into the supernatant indicated successful viral assembly and egress. Crystal violet staining revealed progressive cytomorphological changes in all osteosarcoma cell lines. Infection of osteosarcoma cell lines with the standard H-1PV caused an arrest of the cell cycle in the G2 phase, and these lines had a limited capacity for standard H-1PV virus replication. The cytotoxicity of wild-type H-1PV virus towards osteosarcoma cells was compared in vitro with that of two variants, Del H-1PV and DM H-1PV, previously described as fitness variants displaying higher infectivity and spreading in human transformed cell lines of different origins. Surprisingly, wild-type H-1PV displayed the strongest cytostatic and cytotoxic effects in this analysis and thus seems the most promising for the next preclinical validation steps in vivo.

The nature of outsourced preclinical research--the example of chemical synthesis.

Science.gov (United States)

Festel, Gunter W

2013-09-01

The possibility to buy standardized external services or even new and innovative methods within drug discovery has increased dramatically during the last decades. Service providers are able to provide timely and efficient solutions to any given problem within preclinical research. The outsourcing behavior depends on the specific company type. Generally, the outsourcing level of emerging pharmaceutical and biotechnology companies is much higher than established companies due to low or missing internal resources. Whereas the "make-or-buy" decisions of large and fully integrated pharmaceutical companies are mainly competency driven, those of mid-size and small pharmaceutical, as well as biotech companies show a specific combination of cost/capacity and competency. The three different cooperation models "price competition", "project selection," and "strategic partnership" were identified. For all types of companies, the cooperation model of "strategic partnership" offers access to high-level expertise while reducing fixed costs and complexity. This was shown using chemical synthesis as an example but is also true for other areas of preclinical research.

The SPOTS System: An Ocular Scoring System Optimized for Use in Modern Preclinical Drug Development and Toxicology.

Science.gov (United States)

Eaton, Joshua Seth; Miller, Paul E; Bentley, Ellison; Thomasy, Sara M; Murphy, Christopher J

2017-12-01

To present a semiquantitative ocular scoring system comprising elements and criteria that address many of the limitations associated with systems commonly used in preclinical studies, providing enhanced cross-species applicability and predictive value in modern ocular drug and device development. Revisions to the ocular scoring systems of McDonald-Shadduck and Hackett-McDonald were conducted by board-certified veterinary ophthalmologists at Ocular Services On Demand (OSOD) over the execution of hundreds of in vivo preclinical ocular drug and device development studies and general toxicological investigations. This semiquantitative preclinical ocular toxicology scoring (SPOTS) system was driven by limitations of previously published systems identified by our group's recent review of slit lamp-based scoring systems in clinical ophthalmology, toxicology, and vision science. The SPOTS system provides scoring criteria for the anterior segment, posterior segment, and characterization of intravitreal test articles. Key elements include: standardized slit lamp settings; expansion of criteria to enhance applicability to nonrabbit species; refinement and disambiguation of scoring criteria for corneal opacity, fluorescein staining severity, and aqueous flare; introduction of novel criteria for scoring of aqueous and anterior vitreous cell; and introduction of criteria for findings observed with drugs/devices targeting the posterior segment. A modified Standardization of Uveitis Nomenclature (SUN) system is also introduced to facilitate accurate use of SUN's criteria in laboratory species. The SPOTS systems provide criteria that stand to enhance the applicability of semiquantitative scoring criteria to the full range of laboratory species, in the context of modern approaches to ocular therapeutics and drug delivery and drug and device development.

Guidelines for standard preclinical experiments in the mouse model of myasthenia gravis induced by acetylcholine receptor immunization.

Science.gov (United States)

Tuzun, Erdem; Berrih-Aknin, Sonia; Brenner, Talma; Kusner, Linda L; Le Panse, Rozen; Yang, Huan; Tzartos, Socrates; Christadoss, Premkumar

2015-08-01

Myasthenia gravis (MG) is an autoimmune disorder characterized by generalized muscle weakness due to neuromuscular junction (NMJ) dysfunction brought by acetylcholine receptor (AChR) antibodies in most cases. Although steroids and other immunosuppressants are effectively used for treatment of MG, these medications often cause severe side effects and a complete remission cannot be obtained in many cases. For pre-clinical evaluation of more effective and less toxic treatment methods for MG, the experimental autoimmune myasthenia gravis (EAMG) induced by Torpedo AChR immunization has become one of the standard animal models. Although numerous compounds have been recently proposed for MG mostly by using the active immunization EAMG model, only a few have been proven to be effective in MG patients. The variability in the experimental design, immunization methods and outcome measurements of pre-clinical EAMG studies make it difficult to interpret the published reports and assess the potential for application to MG patients. In an effort to standardize the active immunization EAMG model, we propose standard procedures for animal care conditions, sampling and randomization of mice, experimental design and outcome measures. Utilization of these standard procedures might improve the power of pre-clinical EAMG experiments and increase the chances for identifying promising novel treatment methods that can be effectively translated into clinical trials for MG. Copyright © 2015 Elsevier Inc. All rights reserved.

Decreasing Irradiated Rat Lung Volume Changes Dose-Limiting Toxicity From Early to Late Effects

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Veen, Sonja J. van der; Faber, Hette; Ghobadi, Ghazaleh [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Brandenburg, Sytze [KVI Center for Advanced Radiation Research, University of Groningen, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Coppes, Robert P. [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Luijk, Peter van, E-mail: p.van.luijk@umcg.nl [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)

2016-01-01

Purpose: Technological developments in radiation therapy result in smaller irradiated volumes of normal tissue. Because the risk of radiation therapy-induced toxicity generally depends on irradiated volume, changing volume could change the dose-limiting toxicity of a treatment. Recently, in our rat model, we found that early radiation-induced lung dysfunction (RILD) was closely related to irradiated volume dependent vascular remodeling besides inflammation. The exact relationship between early and late RILD is still unknown. Therefore, in this preclinical study we investigated the dose-volume relationship of late RILD, assessed its dependence on early and late pathologies and studied if decreasing irradiated volume changed the dose-limiting toxicity. Methods and Materials: A volume of 25%, 32%, 50%, 63%, 88%, or 100% of the rat lung was irradiated using protons. Until 26 weeks after irradiation, respiratory rates were measured. Macrovascular remodeling, pulmonary inflammation, and fibrosis were assessed at 26 weeks after irradiation. For all endpoints dose-volume response curves were made. These results were compared to our previously published early lung effects. Results: Early vascular remodeling and inflammation correlated significantly with early RILD. Late RILD correlated with inflammation and fibrosis, but not with vascular remodeling. In contrast to the early effects, late vascular remodeling, inflammation and fibrosis showed a primarily dose but not volume dependence. Comparison of respiratory rate increases early and late after irradiation for the different dose-distributions indicated that with decreasing irradiated volumes, the dose-limiting toxicity changed from early to late RILD. Conclusions: In our rat model, different pathologies underlie early and late RILD with different dose-volume dependencies. Consequently, the dose-limiting toxicity changed from early to late dysfunction when the irradiated volume was reduced. In patients, early and late

Cognitive Deficits in Schizophrenia and Other Neuropsychiatric Disorders: Convergence of Preclinical and Clinical Evidence

Czech Academy of Sciences Publication Activity Database

Stuchlík, Aleš; Sumiyoshi, T.

2014-01-01

Roč. 8, - (2014), s. 444 ISSN 1662-5153 R&D Projects: GA ČR(CZ) GA14-03627S; GA ČR(CZ) GBP304/12/G069; GA MZd(CZ) NT13386; GA MŠk(CZ) LH14053 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M200111204 Institutional support: RVO:67985823 Keywords : cognition * neuropsychiatric disorders * animal models * clinical studies * preclinical studies Subject RIV: FH - Neurology Impact factor: 3.270, year: 2014

Cranberries and Cancer: An Update of Preclinical Studies Evaluating the Cancer Inhibitory Potential of Cranberry and Cranberry Derived Constituents

Directory of Open Access Journals (Sweden)

Katherine M. Weh

2016-08-01

Full Text Available 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.

Designing Preclinical Instruction of Psychomotor Skills (IV)--Instructional Engineering: Evaluation Phase.

Science.gov (United States)

Guenzel, Pamela J.; And Others

1995-01-01

The fourth article in a four-part series on instructional design discusses evaluation of a psychomotor skills unit taught in preclinical dental education. Issues examined include piloting of instructional materials, analysis and revision of materials based on student performance, syllabus design and content, influence of faculty characteristics,…

TMOD-05. MOLECULAR CHARACTERIZATION OF ORTHOTOPIC PATIENT-DERIVED XENOGRAFT MODELS OF PEDIATRIC BRAIN TUMORS AND THEIR USE IN PRECLINICAL EXPERIMENTS

Science.gov (United States)

Brabetz, Sebastian; Schmidt, Christin; Groebner, Susanne N.; Mack, Norman; Seker-Cin, Huriye; Jones, David T.W.; Chavez, Lukas; Milde, Till; Witt, Olaf; Leary, Sarah E.; Li, Xiao-Nan; Wechsler-Reya, Robert J.; Olson, James M.; Pfister, Stefan M.; Kool, Marcel

2017-01-01

Abstract Genomic studies have shown that multiple molecular subtypes of pediatric brain tumors exist that are biologically and clinically highly distinct. These findings ask for novel subtype specific treatments. To develop these we need more and better preclinical models that correctly reflect the proper tumor (sub)type. Orthotopic patient-derived xenograft (PDX) models generated by intracranial injection of primary patient material into the brain of NSG mice offer the unique possibility to test novel substances in primary patient tissue in an in vivo environment. Prior to drug selection and testing, extensive molecular characterizations of PDX and matching primary tumor/blood (DNA methylation, DNA sequencing, and gene expression) are needed to see how the PDX represents the original disease and to learn about targetable oncogenic drivers in each model. In collaboration with several groups around the world we have generated and fully characterized thus far 75 PDX models reflecting 15 distinct subtypes of pediatric brain cancer. PDX models always retain their molecular subtype and in the vast majority of cases also mutations and copy number alterations compared to matching primary tumors. Most aggressive tumors, harboring MYC(N) amplifications, are overrepresented in the cohort, but also subtypes which have not been available for preclinical testing before due to lack of genetically engineered mouse models or suitable cell lines, such as Group 4 medulloblastoma, are included. All models and corresponding molecular data will become available for the community for preclinical research. Examples of such preclinical experiments will be presented. PDX models of pediatric brain tumors are still quite rare. Our repertoire of PDX models and corresponding molecular characterizations allow researchers all over the world to find the right models for their specific scientific questions. It will provide an unprecedented resource to study tumor biology and pave the way for

Preclinical screening for retinopathy of prematurity risk using IGF1 levels at 3 weeks post-partum.

Science.gov (United States)

Pérez-Muñuzuri, Alejandro; Couce-Pico, Maria Luz; Baña-Souto, Ana; López-Suárez, Olalla; Iglesias-Deus, Alicia; Blanco-Teijeiro, José; Fernández-Lorenzo, José Ramón; Fraga-Bermúdez, José María

2014-01-01

Following current recommendations for preventing retinopathy of prematurity (ROP) involves screening a large number of patients. We performed a prospective study to establish a useful screening system for ROP prediction and we have determined that measuring serum levels of IGF1 at week three and the presence of sepsis have a high predictive value for the subsequent development of ROP. A total of 145 premature newborn, with birthweight <1500 g and/or <32 weeks gestational age, were enrolled. 26.9% of them showed some form of retinopathy. A significant association was found between the development of retinopathy and each of the following variables: early gestational age, low birthweight, requiring mechanical ventilation, oxygen treatment, intracranial haemorrhage, sepsis during the first three weeks, bronchopulmonary dysplasia, the need for erythrocyte transfusion, erythropoietin treatment, and low levels of serum IGF1 in the third week. A multiple logistic regression analysis was used to obtain curves for the probability of developing ROP, based on the main factors linked with ROP, namely serum levels of IGF1 and presence of sepsis. Such preclinical screening has the ability to identify patients with high-risk of developing retinopathy and should lead to better prediction for ROP, while at the same time optimising the use of clinical resources, both human and material.

Radiological and clinical outcomes of novel Ti/PEEK combined spinal fusion cages: a systematic review and preclinical evaluation.

Science.gov (United States)

Assem, Yusuf; Mobbs, Ralph J; Pelletier, Matthew H; Phan, Kevin; Walsh, William R

2017-03-01

The primary objective of this paper was to provide a systematic review of the available clinical studies of Ti/PEEK combined cages in spinal interbody fusion surgeries, focusing on their radiological and clinical outcomes. A secondary aim was to provide a review and evaluation of the in vitro and preclinical studies reported on Ti/PEEK-coated implants. A systematic search of the literature was performed in March 2015 via three databases: Medline, Embase and Cochrane library. The following key search terms were combined with synonyms to identify relevant articles: "spinal fusion," "PEEK," "titanium" and "cage." The novelty of this intervention translates into a paucity of clinical trials, albeit the results of the seven clinical studies that met the criteria for inclusion are promising. All studies reported rate of fusion as a primary outcome. Two studies reported slightly improved fusion in the experimental Ti/PEEK combination cohort, one study identical fusion (91.7 %) and three studies excellent fusion (96, 100 and 94 %) in the Ti/PEEK cohort, although no differences reached statistical significance. Clinical studies at this early stage demonstrate that Ti/PEEK implants are safe and efficacious, exhibiting similar fusion rates and clinical outcomes compared to the current standard PEEK. There is clinical evidence substantiating the improved radiographic fusion of Ti/PEEK, albeit the differences were not significant. This field is promising, gaining substantial popularity, and further clinical trials are needed in the future to establish Ti/PEEK cages as a mainstay of clinical practice.

CLINICAL STUDY OF EARLY BREAST CARCINOMA

Directory of Open Access Journals (Sweden)

Kiran Kumar

2016-01-01

Full Text Available Carcinoma of the breast is one of the commonest cancers occurring in female and accounts for 1/3rd of all the malignant diseases occurring in them. It is mainly a disease of the developed countries and accounts for 1,00,000 deaths annually. Breast carcinoma is classified as Early breast cancer, Locally advanced breast cancer and Metastatic breast cancer. By definition early stage breast cancer constitutes breast tumors of clinical stages I, IIa and T2N1M0. Early breast cancer is the one diagnosed by mammography. Women when approaches at this stage, they can go for breast conservation surgery. Not all women are candidates for this approach, and some require mastectomy as part of their treatment. AIM To observe the incidence of early breast carcinoma with particular reference to the time taken by the patients to seek medical advice after the symptoms have developed i.e. the average time taken by the patients to seek medical advice, their appropriate management and prognosis. MATERIALS AND METHODS This prospective study was conducted over a period of 2 years from Oct-2012 to Oct-2014 in 30 female patients aged between 25-65 years who were presented with lump in breast of size ≤5cms with or without pain, with or without lymph nodes to the outpatient department. All the patients were thoroughly asked about history, examined clinically, investigated, staged and managed by surgery either Breast Conservation Surgery or Modified Radical Mastectomy. Postoperative complications were recorded and followed up regularly. RESULTS The incidence of early breast cancer in this study was 0.98% with peak age incidence between 40-60 years and duration of symptoms <6 months in 18 patients. Breast Conservation Surgery + axillary dissection + Radiotherapy was done in 23%. Prognosis was good in these patients with no local recurrence and death. CONCLUSION The prognosis of early stage breast carcinoma patients in this study was good. To have long term tumor free and

Epidermal growth factor receptor (EGFR) mutations in lung cancer: preclinical and clinical data

Energy Technology Data Exchange (ETDEWEB)

Jorge, S.E.D.C.; Kobayashi, S.S.; Costa, D.B. [Harvard Medical School, Beth Israel Deaconess Medical Center, Department of Medicine, Division of Hematology/Oncology, Boston, MA (United States)

2014-09-05

Lung cancer leads cancer-related mortality worldwide. Non-small-cell lung cancer (NSCLC), the most prevalent subtype of this recalcitrant cancer, is usually diagnosed at advanced stages, and available systemic therapies are mostly palliative. The probing of the NSCLC kinome has identified numerous nonoverlapping driver genomic events, including epidermal growth factor receptor (EGFR) gene mutations. This review provides a synopsis of preclinical and clinical data on EGFR mutated NSCLC and EGFR tyrosine kinase inhibitors (TKIs). Classic somatic EGFR kinase domain mutations (such as L858R and exon 19 deletions) make tumors addicted to their signaling cascades and generate a therapeutic window for the use of ATP-mimetic EGFR TKIs. The latter inhibit these kinases and their downstream effectors, and induce apoptosis in preclinical models. The aforementioned EGFR mutations are stout predictors of response and augmentation of progression-free survival when gefitinib, erlotinib, and afatinib are used for patients with advanced NSCLC. The benefits associated with these EGFR TKIs are limited by the mechanisms of tumor resistance, such as the gatekeeper EGFR-T790M mutation, and bypass activation of signaling cascades. Ongoing preclinical efforts for treating resistance have started to translate into patient care (including clinical trials of the covalent EGFR-T790M TKIs AZD9291 and CO-1686) and hold promise to further boost the median survival of patients with EGFR mutated NSCLC.

Epidermal growth factor receptor (EGFR) mutations in lung cancer: preclinical and clinical data

International Nuclear Information System (INIS)

Jorge, S.E.D.C.; Kobayashi, S.S.; Costa, D.B.

2014-01-01

Lung cancer leads cancer-related mortality worldwide. Non-small-cell lung cancer (NSCLC), the most prevalent subtype of this recalcitrant cancer, is usually diagnosed at advanced stages, and available systemic therapies are mostly palliative. The probing of the NSCLC kinome has identified numerous nonoverlapping driver genomic events, including epidermal growth factor receptor (EGFR) gene mutations. This review provides a synopsis of preclinical and clinical data on EGFR mutated NSCLC and EGFR tyrosine kinase inhibitors (TKIs). Classic somatic EGFR kinase domain mutations (such as L858R and exon 19 deletions) make tumors addicted to their signaling cascades and generate a therapeutic window for the use of ATP-mimetic EGFR TKIs. The latter inhibit these kinases and their downstream effectors, and induce apoptosis in preclinical models. The aforementioned EGFR mutations are stout predictors of response and augmentation of progression-free survival when gefitinib, erlotinib, and afatinib are used for patients with advanced NSCLC. The benefits associated with these EGFR TKIs are limited by the mechanisms of tumor resistance, such as the gatekeeper EGFR-T790M mutation, and bypass activation of signaling cascades. Ongoing preclinical efforts for treating resistance have started to translate into patient care (including clinical trials of the covalent EGFR-T790M TKIs AZD9291 and CO-1686) and hold promise to further boost the median survival of patients with EGFR mutated NSCLC

Preclinical quantitative MicroPET imaging in evaluation of neuroprotective drug candidates

International Nuclear Information System (INIS)

Son, Ji Yeon; Kim, Yu Kyeong; Kim, Ji Sun; Lee, Byung Chul; Kim, Kyeong Min; Choi, Tae Hyun; Cheon, Gi Jeong; Lee, Won Woo; Kim, Sang Eun

2007-01-01

Using in vivo molecular imaging with microPET/SPECT has been expected to facilitate drug discovery and development. In this study, we applied quantitative microPET to the preclinical evaluation of the effects of two neuroprotective drug candidates to the nigrostriatal dopaminergic neuronal damage. Fifteen SD rats were divided into three groups. The rats of each group were orally administrated one of neuroprotective candidate; NeuProtec (100mg/kg bid) and SureCero (10mg/kg, qd) or normal saline (0.1ml, qd) for 3 weeks. 6-OHDA was sterotactically placed to the right striatum on eighth day after starting while continuing the medication for additional 14 days. [ 124 I]FP-ClT PET scans were obtained using microPET R4 scanner. The behavioral test by amphetamine-induced rotation and the histological examination after thyrosine hydroxylase (TH) immunohistochemical staining were performed. Different uptake in the lesioned striatum among the groups were demonstrated on [ 124 I]FP-CIT PET images. The rats with NeuProtec showed higher binding in the lesion than controls. No differences were observed in SureCere groups. The FP-CIT uptake in the lesioned striatum was well correlated with the % reduction of TH(+) cells (rho =0.73, p=0.025), and also correlated with rotation test (rho =0.79, p=0.001) [ 124 I]FP-CIT animal PET depicted the neuroprotective effects of NeuProtec to the 6-OHDA neurotoxicity in the rat striatum. No demonstrable effect of SureCero might indicate that inadequate dosage was used in this study. MicroPET imaging with small animal could be a great tool in preclinical evaluation of drug efficacy

The impact of weakly bound ⁸⁹Zr on preclinical studies: Non-specific accumulation in solid tumors and aspergillus infection

DEFF Research Database (Denmark)

Severin, Gregory; Jørgensen, Jesper T.; Wiehr, Stefan

2015-01-01

free or weakly bound 89Zr released in circulation. 89Zr oxalate had the desired characteristics, and was injected into mice bearing FaDu and HT29 solid tumor xenografts, and mice infected in the lungs with the mold Aspergillus fumigatus, as well as in healthy controls (naïve). PET/CT and PET/MR imaging...... followed to quantify the distribution of the radionuclide in the disease models. Results 89Zr oxalate was found to have a plasma half-life of 5.1 ± 2.3 h, accumulating mainly in the bones of all animals. Both tumor types accumulated 89Zr on the order of 2-4% ID/cm3, which is comparable to EPR...... in the disease sites in the present study, we recommend control experiments mapping the biodistribution of free 89Zr in any preclinical study employing 89Zr where bone uptake is observed. Aqueous 89Zr oxalate appears to be a suitable compound for such studies. This is especially relevant in studies where...

The Checkpoint Kinase 1 Inhibitor Prexasertib Induces Regression of Preclinical Models of Human Neuroblastoma.

Science.gov (United States)

Lowery, Caitlin D; VanWye, Alle B; Dowless, Michele; Blosser, Wayne; Falcon, Beverly L; Stewart, Julie; Stephens, Jennifer; Beckmann, Richard P; Bence Lin, Aimee; Stancato, Louis F

2017-08-01

Purpose: Checkpoint kinase 1 (CHK1) is a key regulator of the DNA damage response and a mediator of replication stress through modulation of replication fork licensing and activation of S and G 2 -M cell-cycle checkpoints. We evaluated prexasertib (LY2606368), a small-molecule CHK1 inhibitor currently in clinical testing, in multiple preclinical models of pediatric cancer. Following an initial assessment of prexasertib activity, this study focused on the preclinical models of neuroblastoma. Experimental Design: We evaluated the antiproliferative activity of prexasertib in a panel of cancer cell lines; neuroblastoma cell lines were among the most sensitive. Subsequent Western blot and immunofluorescence analyses measured DNA damage and DNA repair protein activation. Prexasertib was investigated in several cell line-derived xenograft mouse models of neuroblastoma. Results: Within 24 hours, single-agent prexasertib promoted γH2AX-positive double-strand DNA breaks and phosphorylation of DNA damage sensors ATM and DNA-PKcs, leading to neuroblastoma cell death. Knockdown of CHK1 and/or CHK2 by siRNA verified that the double-strand DNA breaks and cell death elicited by prexasertib were due to specific CHK1 inhibition. Neuroblastoma xenografts rapidly regressed following prexasertib administration, independent of starting tumor volume. Decreased Ki67 and increased immunostaining of endothelial and pericyte markers were observed in xenografts after only 6 days of exposure to prexasertib, potentially indicating a swift reduction in tumor volume and/or a direct effect on tumor vasculature. Conclusions: Overall, these data demonstrate that prexasertib is a specific inhibitor of CHK1 in neuroblastoma and leads to DNA damage and cell death in preclinical models of this devastating pediatric malignancy. Clin Cancer Res; 23(15); 4354-63. ©2017 AACR . ©2017 American Association for Cancer Research.

A review of treatment planning for precision image-guided photon beam pre-clinical animal radiation studies

International Nuclear Information System (INIS)

Verhaegen, Frank; Hoof, Stefan van; Granton, Patrick V.; Trani, Daniela

2014-01-01

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.

The role of metabotropic glutamate receptor 5 in the pathogenesis of mood disorders and addiction:Combining preclinical evidence with human Positron Emission Tomography (PET studies

Directory of Open Access Journals (Sweden)

Sylvia eTerbeck

2015-03-01

Full Text Available In the present review, we deliver an overview of the involvement of metabotropic glutamate receptor 5 (mGluR5 activity and density in pathological anxiety, mood disorders and addiction. Specifically, we will describe mGluR5 studies in humans that employed Positron Emission Tomography (PET and combined the findings with preclinical animal research. This combined view of different methodological approaches — from basic neurobiological approaches to human studies — might give a more comprehensive and clinically relevant view of mGluR5 function in mental health than the view on preclinical data alone. We will also review the current research data on mGluR5 along the Research Domain Criteria (RDoC. Firstly, we found evidence of abnormal glutamate activity related to the positive and negative valence systems, which would suggest that antagonistic mGluR5 intervention has prominent anti-addictive, anti-depressive and anxiolytic effects. Secondly, there is evidence that mGluR5 plays in important role in systems for social functioning and the response to social stress. Finally, mGluR5’s important role in sleep homeostasis suggests that this glutamate receptor may play an important role in RDoC’s arousal and modulatory systems domain. Glutamate was previously mostly investigate in non-human studies, however initial human clinical PET research now also supports the hypothesis that, by mediating brain excitability, neuroplasticity and social cognition, abnormal metabotropic glutamate activity might predispose individuals to a broad range of psychiatric problems.

Common data elements for preclinical epilepsy research: Standards for data collection and reporting. A TASK3 report of the AES/ILAE Translational Task Force of the ILAE.

Science.gov (United States)

Harte-Hargrove, Lauren C; French, Jacqueline A; Pitkänen, Asla; Galanopoulou, Aristea S; Whittemore, Vicky; Scharfman, Helen E

2017-11-01

The major objective of preclinical translational epilepsy research is to advance laboratory findings toward clinical application by testing potential treatments in animal models of seizures and epilepsy. Recently there has been a focus on the failure of preclinical discoveries to translate reliably, or even to be reproduced in different laboratories. One potential cause is a lack of standardization in preclinical data collection. The resulting difficulties in comparing data across studies have led to high cost and missed opportunity, which in turn impede clinical trials and advances in medical care. Preclinical epilepsy research has successfully brought numerous antiseizure treatments into the clinical practice, yet the unmet clinical needs have prompted the reconsideration of research strategies to optimize epilepsy therapy development. In the field of clinical epilepsy there have been successful steps to improve such problems, such as generation of common data elements (CDEs) and case report forms (CRFs and standards of data collection and reporting) by a team of leaders in the field. Therefore, the Translational Task Force was appointed by the International League Against Epilepsy (ILAE) and the American Epilepsy Society (AES), in partnership with the National Institute of Neurological Disorders and Stroke (NINDS) and the National Institutes of Health (NIH) to define CDEs for animal epilepsy research studies and prepare guidelines for data collection and experimental procedures. If adopted, the preclinical CDEs could facilitate collaborative epilepsy research, comparisons of data across different laboratories, and promote rigor, transparency, and impact, particularly in therapy development. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Cortico-amygdala coupling as a marker of early relapse risk in cocaine-addicted individuals

Directory of Open Access Journals (Sweden)

Meredith J Mchugh

2014-02-01

Full Text Available Addiction to cocaine is a chronic condition characterized by high rates of early relapse. This study builds on efforts to identify neural markers of relapse risk by studying resting state functional connectivity (rsFC in neural circuits arising from the amygdala; a brain region implicated in relapse-related processes including craving and reactivity to stress following acute and protracted withdrawal from cocaine. Whole-brain resting-state fMRI connectivity (6 min was assessed in 45 cocaine-addicted individuals and 22 healthy controls. Cocaine-addicted individuals completed scans in the final week of a residential treatment episode. To approximate preclinical models of relapse-related circuitry separate seeds were derived for the left and right basolateral (BLA and corticomedial (CMA amygdala. Participants also completed the Iowa Gambling Task, Wisconsin Card Sorting Test, Cocaine Craving Questionnaire, Obsessive Compulsive Cocaine Use scale, Temperament and Character Inventory and the NEO-PI-R. Relapse within the first 30 days post-treatment (n = 24 was associated with reduced rsFC between the left CMA and ventromedial prefrontal cortex/rostral anterior cingulate cortex (vmPFC/rACC relative to cocaine-addicted individuals who remained abstinent (non-relapse, n = 21. Non-relapse participants evidenced reduced rsFC between the bilateral BLA and visual processing regions (lingual gyrus/cuneus compared to controls and relapsed participants. Early relapse was associated with fewer years of education but unrelated to trait reactivity to stress, neurocognitive and clinical characteristics or cocaine use history. Findings suggest that rsFC within neural circuits implicated in preclinical models of relapse may provide a promising marker of relapse risk in cocaine-addicted individuals. Future efforts to replicate the current findings and alter connectivity within these circuits may yield novel interventions and improve treatment outcomes.

Growth/differentiation factor-5: a candidate therapeutic agent for periodontal regeneration? A review of pre-clinical data.

Science.gov (United States)

Moore, Yolanda R; Dickinson, Douglas P; Wikesjö, Ulf M E

2010-03-01

Therapeutic concepts involving the application of matrix, growth and differentiation factors have been advocated in support of periodontal wound healing/regeneration. Growth/differentiation factor-5 (GDF-5), a member of the bone morphogenetic protein family, represents one such factor. The purpose of this review is to provide a background of the therapeutic effects of GDF-5 expressed in various musculoskeletal settings using small and large animal platforms. A comprehensive literature search was conducted to identify all reports in the English language evaluating GDF-5 using the PubMed and Google search engines, and a manual search of the reference lists from the electronically retrieved reports. Two reviewers independently screened the titles and abstracts from a total of 69 reports, 22 of which were identified as pre-clinical (in vivo) evaluations of GDF-5. The full-length article of the 22 pre-clinical reports was then reviewed. Various applications including cranial and craniofacial bone formation, spine fusion, long bone fracture healing, cartilage, and tendon/ligament repair using a variety of small and large animal platforms evaluating GDF-5 as a therapeutic agent were identified. A majority of studies, using biomechanical, radiographic, and histological analysis, demonstrated significant dose-dependent effects of GDF-5. These include increased/enhanced local bone formation, fracture healing/repair, and cartilage and tendon/ligament formation. GDF-5 frequently was shown to accelerate wound maturation. Several studies demonstrated GDF-5 to be a realistic alternative to autograft bone. Studies using pre-clinical models and human histology suggest GDF-5 may also increase/enhance periodontal wound healing/regeneration. GDF-5 appears a promising therapeutic agent for periodontal wound healing/regeneration as GDF-5 supports/accelerates bone and tendon/ligament formation in several musculoskeletal settings including periodontal tissues.

Preclinical Science Regarding Cannabinoids as Analgesics: An Overview

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ME Lynch

2005-01-01

Full Text Available Modern pharmacology of cannabinoids began in 1964 with the isolation and partial synthesis of delta-9-tetrahydrocannabinol, the main psychoactive agent in herbal cannabis. Since then, potent antinociceptive and antihyperalgesic effects of cannabinoid agonists in animal models of acute and chronic pain; the presence of cannabinoid receptors in pain-processing areas of the brain, spinal cord and periphery; and evidence supporting endogenous modulation of pain systems by cannabinoids has provided support that cannabinoids exhibit significant potential as analgesics. The present article presents an overview of the preclinical science.

Pre-Clinical Traumatic Brain Injury Common Data Elements: Toward a Common Language Across Laboratories.

Science.gov (United States)

Smith, Douglas H; Hicks, Ramona R; Johnson, Victoria E; Bergstrom, Debra A; Cummings, Diana M; Noble, Linda J; Hovda, David; Whalen, Michael; Ahlers, Stephen T; LaPlaca, Michelle; Tortella, Frank C; Duhaime, Ann-Christine; Dixon, C Edward

2015-11-15

Traumatic brain injury (TBI) is a major public health issue exacting a substantial personal and economic burden globally. With the advent of "big data" approaches to understanding complex systems, there is the potential to greatly accelerate knowledge about mechanisms of injury and how to detect and modify them to improve patient outcomes. High quality, well-defined data are critical to the success of bioinformatics platforms, and a data dictionary of "common data elements" (CDEs), as well as "unique data elements" has been created for clinical TBI research. There is no data dictionary, however, for preclinical TBI research despite similar opportunities to accelerate knowledge. To address this gap, a committee of experts was tasked with creating a defined set of data elements to further collaboration across laboratories and enable the merging of data for meta-analysis. The CDEs were subdivided into a Core module for data elements relevant to most, if not all, studies, and Injury-Model-Specific modules for non-generalizable data elements. The purpose of this article is to provide both an overview of TBI models and the CDEs pertinent to these models to facilitate a common language for preclinical TBI research.

Utility of immunodeficient mouse models for characterizing the preclinical pharmacokinetics of immunogenic antibody therapeutics.

Science.gov (United States)

Myzithras, Maria; Bigwarfe, Tammy; Li, Hua; Waltz, Erica; Ahlberg, Jennifer; Giragossian, Craig; Roberts, Simon

Prior to clinical studies, the pharmacokinetics (PK) of antibody-based therapeutics are characterized in preclinical species; however, those species can elicit immunogenic responses that can lead to an inaccurate estimation of PK parameters. Immunodeficient (SCID) transgenic hFcRn and C57BL/6 mice were used to characterize the PK of three antibodies that were previously shown to be immunogenic in mice and cynomolgus monkeys. Four mouse strains, Tg32 hFcRn SCID, Tg32 hFcRn, SCID and C57BL/6, were administered adalimumab (Humira®), mAbX and mAbX-YTE at 1 mg/kg, and in SCID strains there was no incidence of immunogenicity. In non-SCID strains, drug-clearing ADAs appeared after 4-7 days, which affected the ability to accurately calculate PK parameters. Single species allometric scaling of PK data for Humira® in SCID and hFcRn SCID mice resulted in improved human PK predictions compared to C57BL/6 mice. Thus, the SCID mouse model was demonstrated to be a useful tool for assessing the preclinical PK of immunogenic therapeutics.

Preclinical pharmacological studies of 99Tcm-TRODAT-1 as a dopamine transporter imaging agent

International Nuclear Information System (INIS)

Fang Ping; Wan Weixing; Liu Zhenguo; Wu Chunying; Chen Shengdi; Chen Zhengping; Zhou Xiang; Ji Shuren

2001-01-01

Objective: To develop a 99 Tc m labelled dopamine transporter (DAT) imaging agent, 99 Tc m -TRODAT-1 [TRODAT-1: 2β-([N,N'-bis(2-mercaptoethyl) ethylene diamino] methyl), 3β-(4-chlorophenyl) tropane], for evaluating the variation of DAT in patients with Parkinson's disease. Methods: 99 Tc m -TRODAT-1 was successfully prepared on a kit basis. Preclinical pharmacological studies were performed in rats, mice, rabbits, monkeys and a volunteer with diagnosed Parkinson disease (PD). Results: Radiochemical purity of 99 Tc m -TRODAT-1 was over 90%, and remained stable for 6 hours. The specific uptake in striatum was significantly diminished, from 3.45 to 0.12 at 2 h by pretreating rats with a dose of DAT competing ligand, β-CIT [1 mg/kg, 2β-carbomethoxy-3β-(4-iodophenyl) tropane]. Blood clearance kinetics was studied in rabbits, and the initial half-life was of 1.2 min, the elimination half-life was of 368 min. Images of normal monkey's brain exhibited an excellent accumulation in basal ganglia region, where dopamine neurons were concentrated. In hemi parkinsonism model monkeys, the ratio of normal ST/CB and lesioned ST/CB were 1.56 and 0.94, respectively. Brain imaging studies in volunteer indicated that uptake and retention in the basal ganglia, the ratio of normal striatal uptake to lesioned one's was 1.15 measured by SPECT imaging at 2 h. The result of imaging was conformable with his clinical symptoms. Conclusions: The stable, neutral and lipophilic complex, 99 Tc m -TRODAT-1, can be accumulated in the striatal area, where DAT is concentrated, high quality images can be obtained. It suggests that 99 Tc m -TRODAT-1 might be a safe and effective tracer for monitoring the variation in DAT which is associated with various neurodegenerative diseases

NGAL (Neutrophil Gelatinase-associated Lipocalin) is an Early Predictor of Acute Kidney Injury after Cardiac Surgery and Variation of NGAL Values in Homogenous Study Subject.

Science.gov (United States)

Miah, O F; Dowel, F A; Latif, A; Hai, A N; Mahmud, M A; Razzak, M A; Ahammod, T

2018-01-01

Isolated CABG (coronary artery bypass grafting) has the lowest incidence of AKI (Acute Kidney Injury), followed by valvular surgery and then, combined CABG with valvular surgery. Due to the difference in baseline characteristics and in surgery type, the range of incidence is between 8.9 and 39% based on RIFLE (Risk Injury failure loss end stage kidney disease) or AKIN (Acute Kidney Injury Network) criteria. The advent of novel biomarkers of kidney injury has opened a new era of early detection and prognosis prediction for AKI. NGAL is a small molecule of 178 amino acids that belongs to the super family of lipocalins, which are proteins specialized in binding and transporting small hydrophobic molecules. The expression of NGAL raises 1000 fold in humans and rodents in response to renal tubular injury and it appears so rapidly in the urine and serum that it is useful as an early biomarker of renal failure. The role of plasma NGAL to classify AKI severity and predict the need for RRT (renal replacement therapy) after cardiac surgery has been suggested. Although study subjects were more or less from same cohort (All undergone cardiac surgery), previous studies showed that NGAL raised differently in different proportion. NGAL as an early AKI marker has successfully passed through the pre-clinical, assay development and initial clinical testing stages. It is badly need to enter in a consensus about the cutoff value of NGAL which should help the physician about leveling a case as AKI or non AKI and their consequence management.

Reconstitution of immunodeficient SCID/beige mice with human cells: Applications in preclinical studies

International Nuclear Information System (INIS)

Thomsen, Mogens; Galvani, Sylvain; Canivet, Cindy; Kamar, Nassim; Boehler, Torsten

2008-01-01

Experimental studies of the in vivo behaviour of human cells and tissues have become possible with the development of immunodeficient mice strains. Such mice accept readily allogeneic or xenogeneic grafts, including grafts of human cells or tissues, without rejection. In this review we describe different immunodeficient mouse strains that have been used for reconstitution by human immune cells. We subsequently go through the experience that we and others have had with reconstitution, and mention the adverse effects, in particular xenogeneic graft versus host reactions. The use of haematopoietic stem cells avoids such reactions but the immunological reconstitution may take several months. We then report the use of immunodeficient mice for the study of chronic vascular rejection of human mesenteric arteries due to cellular or humoral alloreaction. We have shown that SCID/beige mice grafted with a human artery at the place of the aorta developed a thickening of the intima of the human artery after 5-6 weeks, when they were reconstituted with spleen cells from another human donor. The thickening is mainly due to a proliferation of smooth muscle cells. The same type of lesion developed if they received injection of antibodies towards HLA class I antigens. The arteries of the mouse did not develop any lesion. The arterial lesions closely resembled those seen after clinical organ transplantation. Mice that received spleen cells from the same human donor developed little or no lesions. An important aspect of this experimental transplantation model is the possibility to test drugs that may be used in clinical transplantation. In recent experiments we have shown that novel immunosuppressive drugs can inhibit the hyperproliferation of smooth muscle cells in vitro. Preclinical testing in reconstituted SCID/beige mice grafted with human arteries will permit the evaluation of the potential use of these drugs to prevent chronic vascular rejection. The model also allows

Striatal dopamine D2 receptors, metabolism, and volume in preclinical Huntington disease

NARCIS (Netherlands)

van Oostrom, JCH; Maguire, RP; Verschuuren-Bemelmans, CC; van der Duin, LV; Pruim, J; Roos, RAC; Leenders, KL

2005-01-01

Among 27 preclinical carriers of the Huntington disease mutation (PMC), the authors found normal striatal values for MRI volumetry in 88% and for fluorodesoxyglucose PET metabolic index in 67%. Raclopride PET binding potential (RAC-BP) was decreased in 50% and correlated with increases in the

Ethical Considerations of Preclinical Testing

Directory of Open Access Journals (Sweden)

Allen Goldenthal

2015-12-01

Full Text Available The numbers of animal tests being conducted are on a sharp incline.  Much of this increase is directly due to our ability to generate transgenic models and knock-outs, thereby increasing the validity of the animal model but not necessarily correlating directly with any translational medical benefits to the human counterpart.  In spite of our best efforts, there still exist species differences that prevent the application directly from animal to human, and in some examples having a completely different and adverse effect from that seen in the animal model. There are several ways in which we can improve the opportunity for a positive test outcome and at the same time reduce the animal usage which is associated with our current animal testing practices. The benefit of the 3R’s is that they encourage us not only to avoid wastage of life but that they require us to provide considerable foresight and extrapolated thought before directly engaging in the preclinical testing phase.

Preclinical incorporation dosimetry of (+)-[18F) flubatine in piglets

International Nuclear Information System (INIS)

Sattler, B.; Patt, M.; Sabri, O.; Kranz, M.; Donat, C.K.; Deuther-Conrad, W.; Fischer, S.; Brust, P.; Sattler, T.; Smits, R.; Hoepping, A.; Steinbach, J.

2015-01-01

Full text of publication follows. Aim: (+)-[ 18 F] flubatine is the mirror image isomer of (-)-[ 18 F] flubatine, which is successfully used for neuroimaging of alpha4beta2 nAChRs with PET. To assess the radiation risk by this new radiotracer, biodistribution, organ doses (OD) and the effective dose (ED) were investigated in a preclinical trials using piglets. Method: whole body dosimetry of (+)-[ 18 F] flubatine was performed in 3 female piglets (age: 43 ± 1.2 days, weight: 14 ± 1.0 kg). The animals were narcotized using 20 mg/kg Ketamine, 2 mg/kg Azaperone; 1.5% Isoflurane in 70% N 2 O/30% O 2 and sequentially PET-imaged up to 5 hours post i.v. injection of 183.5 ± 9.0 MBq on a SIEMENS Biograph16 PET/CT-system on 7 bed positions (BP) per frame, 1.5 to 6 min/BP, CT-attenuation correction (AC) and iterative reconstruction. All relevant organs were defined by volumes of interest. Exponential curves were fitted to the time-activity-data (%ID/g, and %ID/organ). Time- and mass-scales were adapted to the human order of magnitude. The ODs were calculated using the adult male model with OLINDA. The ED was calculated using tissue weighting factors as published in the ICRP103. Results: The highest OD was received by the urinary bladder (71.7 ± 26.3 μSv/MBq), the kidneys (45.1 ± 6.5 μSv/MBq) and the brain (32.3 ± 3.24 μSv/MBq). The highest contribution to the ED was by the urinary bladder (2.9 ± 1.1 μSv/MBq), the lungs (1.7 ± 0.02 μSv/MBq) and the red marrow (1.4 ± 0.1μSv/MBq). According to this data, the ED to humans is 14.3 ± 0.3 μSv/MBq. Conclusion: considering 40% underestimation of the ED to humans by preclinical dosimetry [1] the expected ED to humans after 300 MBq i.v. is 7.2 mSv, which is about the ED by (-)-[ 18 F]flubatine (6.8 mSv/300 MBq) and well within the range of what other 18 F-labeled compounds cause to humans. This risk assessment encourages to transfer (+)-[F 18 ] flubatine from preclinical to clinical study phases and to further develop

The relationship between learning preferences (styles and approaches) and learning outcomes among pre-clinical undergraduate medical students

OpenAIRE

Liew, Siaw-Cheok; Sidhu, Jagmohni; Barua, Ankur

2015-01-01

Background Learning styles and approaches of individual undergraduate medical students vary considerably and as a consequence, their learning needs also differ from one student to another. This study was conducted to identify different learning styles and approaches of pre-clinical, undergraduate medical students and also to determine the relationships of learning preferences with performances in the summative examinations. Methods A cross-sectional study was conducted among randomly selected...

Personal computer versus personal computer/mobile device combination users' preclinical laboratory e-learning activity.

Science.gov (United States)

Kon, Haruka; Kobayashi, Hiroshi; Sakurai, Naoki; Watanabe, Kiyoshi; Yamaga, Yoshiro; Ono, Takahiro

2017-11-01

The aim of the present study was to clarify differences between personal computer (PC)/mobile device combination and PC-only user patterns. We analyzed access frequency and time spent on a complete denture preclinical website in order to maximize website effectiveness. Fourth-year undergraduate students (N=41) in the preclinical complete denture laboratory course were invited to participate in this survey during the final week of the course to track login data. Students accessed video demonstrations and quizzes via our e-learning site/course program, and were instructed to view online demonstrations before classes. When the course concluded, participating students filled out a questionnaire about the program, their opinions, and devices they had used to access the site. Combination user access was significantly more frequent than PC-only during supplementary learning time, indicating that students with mobile devices studied during lunch breaks and before morning classes. Most students had favorable opinions of the e-learning site, but a few combination users commented that some videos were too long and that descriptive answers were difficult on smartphones. These results imply that mobile devices' increased accessibility encouraged learning by enabling more efficient time use between classes. They also suggest that e-learning system improvements should cater to mobile device users by reducing video length and including more short-answer questions. © 2016 John Wiley & Sons Australia, Ltd.

Preclinical Testing of an Oncolytic Parvovirus: Standard Protoparvovirus H-1PV Efficiently Induces Osteosarcoma Cell Lysis In Vitro

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Carsten Geiss

2017-10-01

Full Text Available Osteosarcoma is the most frequent malignant disease of the bone. On the basis of early clinical experience in the 1960s with H-1 protoparvovirus (H-1PV in osteosarcoma patients, this effective oncolytic virus was selected for systematic preclinical testing on various osteosarcoma cell cultures. A panel of five human osteosarcoma cell lines (CAL 72, H-OS, MG-63, SaOS-2, U-2OS was tested. Virus oncoselectivity was confirmed by infecting non-malignant human neonatal fibroblasts and osteoblasts used as culture models of non-transformed mesenchymal cells. H-1PV was found to enter osteosarcoma cells and to induce viral DNA replication, transcription of viral genes, and translation to viral proteins. After H-1PV infection, release of infectious viral particles from osteosarcoma cells into the supernatant indicated successful viral assembly and egress. Crystal violet staining revealed progressive cytomorphological changes in all osteosarcoma cell lines. Infection of osteosarcoma cell lines with the standard H-1PV caused an arrest of the cell cycle in the G2 phase, and these lines had a limited capacity for standard H-1PV virus replication. The cytotoxicity of wild-type H-1PV virus towards osteosarcoma cells was compared in vitro with that of two variants, Del H-1PV and DM H-1PV, previously described as fitness variants displaying higher infectivity and spreading in human transformed cell lines of different origins. Surprisingly, wild-type H-1PV displayed the strongest cytostatic and cytotoxic effects in this analysis and thus seems the most promising for the next preclinical validation steps in vivo.

Preclinical Studies of a Kidney Safe Iodinated Contrast Agent.

Science.gov (United States)

Rowe, Elizabeth S; Rowe, Vernon D; Biswas, Sangita; Mosher, Gerold; Insisienmay, Lovella; Ozias, Marlies K; Gralinski, Michael R; Hunter, John; Barnett, James S

2016-09-01

Contrast-induced acute kidney injury (CI-AKI) is a serious complication of the use of iodinated contrast agents. This problem is particularly acute in interventional neurology and interventional cardiology, probably due to the intra-arterial route of injection, high contrast volumes, and preexisting risk factors of these patients. In an attempt to develop a contrast agent that is less damaging to the kidneys, we have studied the effects of adding a small amount of the substituted cyclodextrin, sulfobutyl-ether-β-cyclodextrin (SBECD), to iohexol in rodent models of renal toxicity. Renally compromised mice and rats were injected with iohexol and iohexol-SBECD via the tail vein. The renal pathology, creatinine clearance, and survival benefits of iohexol-SBECD were studied. The safety of direct intra-arterial injection of the iohexol-SBECD formulation was studied in a dog heart model system. Mechanism of action studies in cell culture model using a human kidney cell line was performed using flow cytometry. Nephrotoxicity was significantly reduced using iohexol-SBECD compared to iohexol alone, at mole ratios of iohexol:SBECD of 1:0.025. SBECD increased survival from 50% to 88% in a rat survival study. In the dog heart model, iohexol-SBECD was safe. Cell culture studies suggest that SBECD interferes with the early stages of contrast-induced apoptosis in a human renal cell line. We have shown that the addition of a small amount of SBECD (one molecule of SBECD per 40 iohexol molecules) significantly protects rodent kidneys from CI-AKI. Further development of this new formulation of iodinated contrast is warranted. © 2016 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

Microbeam evolution: From single cell irradiation to preclinical studies

DEFF Research Database (Denmark)

Ghita, Mihaela; Fernandez-Palomo, Cristian; Fukunaga, Hisanori

2018-01-01

Purpose: This review follows the development of microbeam technology from the early days of single cell irradiations, to investigations of specific cellular mechanisms and to the development of new treatment modalities in vivo. A number of microbeam applications are discussed with a focus on prec...... to deliver radiotherapy using plane parallel microbeams, in Microbeam Radiotherapy (MRT)....

Pre-clinical Safety and Off-Target Studies to Support Translation of AAV-Mediated RNAi Therapy for FSHD.

Science.gov (United States)

Wallace, Lindsay M; Saad, Nizar Y; Pyne, Nettie K; Fowler, Allison M; Eidahl, Jocelyn O; Domire, Jacqueline S; Griffin, Danielle A; Herman, Adam C; Sahenk, Zarife; Rodino-Klapac, Louise R; Harper, Scott Q

2018-03-16

RNAi emerged as a prospective molecular therapy nearly 15 years ago. Since then, two major RNAi platforms have been under development: oligonucleotides and gene therapy. Oligonucleotide-based approaches have seen more advancement, with some promising therapies that may soon reach market. In contrast, vector-based approaches for RNAi therapy have remained largely in the pre-clinical realm, with limited clinical safety and efficacy data to date. We are developing a gene therapy approach to treat the autosomal-dominant disorder facioscapulohumeral muscular dystrophy. Our strategy involves silencing the myotoxic gene DUX4 using adeno-associated viral vectors to deliver targeted microRNA expression cassettes (miDUX4s). We previously demonstrated proof of concept for this approach in mice, and we are now taking additional steps here to assess safety issues related to miDUX4 overexpression and sequence-specific off-target silencing. In this study, we describe improvements in vector design and expansion of our miDUX4 sequence repertoire and report differential toxicity elicited by two miDUX4 sequences, of which one was toxic and the other was not. This study provides important data to help advance our goal of translating RNAi gene therapy for facioscapulohumeral muscular dystrophy.

The sheep as a model of preclinical safety and pharmacokinetic evaluations of candidate microbicides.

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Holt, Jonathon D S; Cameron, David; Dias, Nicola; Holding, Jeremy; Muntendam, Alex; Oostebring, Freddy; Dreier, Peter; Rohan, Lisa; Nuttall, Jeremy

2015-07-01

When developing novel microbicide products for the prevention of HIV infection, the preclinical safety program must evaluate not only the active pharmaceutical ingredient but also the product itself. To that end, we applied several relatively standard toxicology study methodologies to female sheep, incorporating an assessment of the pharmacokinetics, safety, tolerability, and local toxicity of a dapivirine-containing human vaginal ring formulation (Dapivirine Vaginal Ring-004). We performed a 3-month general toxicology study, a preliminary pharmacokinetic study using drug-loaded vaginal gel, and a detailed assessment of the kinetics of dapivirine delivery to plasma, vaginal, and rectal fluid and rectal, vaginal, and cervical tissue over 28 days of exposure and 3 and 7 days after removal of the ring. The findings of the general toxicology study supported the existing data from both preclinical and clinical studies in that there were no signs of toxicity related to dapivirine. In addition, the presence of the physical dapivirine ring did not alter local or systemic toxicity or the pharmacokinetics of dapivirine. Pharmacokinetic studies indicated that the dapivirine ring produced significant vaginal tissue levels of dapivirine. However, no dapivirine was detected in cervical tissue samples using the methods described here. Plasma and vaginal fluid levels were lower than those in previous clinical studies, while there were detectable dapivirine levels in the rectal tissue and fluid. All tissue and fluid levels tailed off rapidly to undetectable levels following removal of the ring. The sheep represents a very useful model for the assessment of the safety and pharmacokinetics of microbicide drug delivery devices, such as the vaginal ring. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

The Australian Medical Schools Assessment Collaboration: benchmarking the preclinical performance of medical students.

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O'Mara, Deborah A; Canny, Ben J; Rothnie, Imogene P; Wilson, Ian G; Barnard, John; Davies, Llewelyn

2015-02-02

To report the level of participation of medical schools in the Australian Medical Schools Assessment Collaboration (AMSAC); and to measure differences in student performance related to medical school characteristics and implementation methods. Retrospective analysis of data using the Rasch statistical model to correct for missing data and variability in item difficulty. Linear model analysis of variance was used to assess differences in student performance. 6401 preclinical students from 13 medical schools that participated in AMSAC from 2011 to 2013. Rasch estimates of preclinical basic and clinical science knowledge. Representation of Australian medical schools and students in AMSAC more than doubled between 2009 and 2013. In 2013 it included 12 of 19 medical schools and 68% of medical students. Graduate-entry students scored higher than students entering straight from school. Students at large schools scored higher than students at small schools. Although the significance level was high (P performance. The effect on performance of multiple assessments compared with the test items as part of a single end-of-year examination was negligible. The variables investigated explain only 12% of the total variation in student performance. An increasing number of medical schools are participating in AMSAC to monitor student performance in preclinical sciences against an external benchmark. Medical school characteristics account for only a small part of overall variation in student performance. Student performance was not affected by the different methods of administering test items.

A comprehensive combined experimental and computational framework for pre-clinical wear simulation of total knee replacements.

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Abdelgaied, A; Fisher, J; Jennings, L M

2018-02-01

A more robust pre-clinical wear simulation framework is required in order to simulate wider and higher ranges of activities, observed in different patient populations such as younger more active patients. Such a framework will help to understand and address the reported higher failure rates for younger and more active patients (National_Joint_Registry, 2016). The current study has developed and validated a comprehensive combined experimental and computational framework for pre-clinical wear simulation of total knee replacements (TKR). The input mechanical (elastic modulus and Poisson's ratio) and wear parameters of the moderately cross-linked ultra-high molecular weight polyethylene (UHMWPE) bearing material were independently measured from experimental studies under realistic test conditions, similar to the loading conditions found in the total knee replacements. The wear predictions from the computational wear simulation were validated against the direct experimental wear measurements for size 3 Sigma curved total knee replacements (DePuy, UK) in an independent experimental wear simulation study under three different daily activities; walking, deep squat, and stairs ascending kinematic conditions. The measured compressive mechanical properties of the moderately cross-linked UHMWPE material were more than 20% lower than that reported in the literature under tensile test conditions. The pin-on-plate wear coefficient of moderately cross-linked UHMWPE was significantly dependant of the contact stress and the degree of cross-shear at the articulating surfaces. The computational wear predictions for the TKR from the current framework were consistent and in a good agreement with the independent full TKR experimental wear simulation measurements, with 0.94 coefficient of determination of the framework. In addition, the comprehensive combined experimental and computational framework was able to explain the complex experimental wear trends from the three different daily

A new mathematical approach for the estimation of the AUC and its variability under different experimental designs in preclinical studies.

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Navarro-Fontestad, Carmen; González-Álvarez, Isabel; Fernández-Teruel, Carlos; Bermejo, Marival; Casabó, Vicente Germán

2012-01-01

The aim of the present work was to develop a new mathematical method for estimating the area under the curve (AUC) and its variability that could be applied in different preclinical experimental designs and amenable to be implemented in standard calculation worksheets. In order to assess the usefulness of the new approach, different experimental scenarios were studied and the results were compared with those obtained with commonly used software: WinNonlin® and Phoenix WinNonlin®. The results do not show statistical differences among the AUC values obtained by both procedures, but the new method appears to be a better estimator of the AUC standard error, measured as the coverage of 95% confidence interval. In this way, the new proposed method demonstrates to be as useful as WinNonlin® software when it was applicable. Copyright © 2011 John Wiley & Sons, Ltd.

Maternal intake of fatty acids and their food sources during lactation and the risk of preclinical and clinical type 1 diabetes in the offspring.

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Niinistö, S; Takkinen, H-M; Uusitalo, L; Rautanen, J; Vainio, N; Ahonen, S; Nevalainen, J; Kenward, M G; Lumia, M; Simell, O; Veijola, R; Ilonen, J; Knip, M; Virtanen, S M

2015-08-01

We examined maternal dietary intake of fatty acids and foods which are sources of fatty acids during lactation and whether they are associated with the risk of preclinical and clinical type 1 diabetes in the offspring. The subjects comprised a cohort of 2,939 mother-child pairs from the prospective Type 1 Diabetes Prediction and Prevention Study. Composition of maternal diet during the third month of lactation was assessed by a validated food frequency questionnaire. Among the children with HLA-conferred susceptibility to type 1 diabetes, 172 developed preclinical and 81 clinical diabetes. Average follow-up for preclinical type 1 diabetes was 7.5 years (range 0.2-14.0 years) and for clinical type 1 diabetes 7.7 years (0.2-14.0 years). Maternal intake of fatty acids during lactation was not associated with the risk of type 1 diabetes in the offspring. After adjusting for putative confounders, maternal total consumption of red meat and meat products during lactation was associated both with increased risk for preclinical [hazard ratio (HR) 1.19, 95 % CI 1.02-1.40, p = 0.038] and clinical type 1 diabetes (HR 1.27, 95 % CI 1.06-1.52, p = 0.025). In particular, consumption of processed meat products showed an association with increased risk for type 1 diabetes (HR 1.23, 95 % CI 1.02-1.48, p = 0.045). Maternal use of vegetable oils was associated with increased risk for preclinical type 1 diabetes (HR 1.21, 95 % CI 1.03-1.41, p = 0.023). Maternal consumption of red meat, especially processed meat, during lactation may increase the risk of type 1 diabetes.

Rat animal model for preclinical testing of microparticle urethral bulking agents.

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Mann-Gow, Travis K; Blaivas, Jerry G; King, Benjamin J; El-Ghannam, Ahmed; Knabe, Christine; Lam, Michael K; Kida, Masatoshi; Sikavi, Cameron S; Plante, Mark K; Krhut, Jan; Zvara, Peter

2015-04-01

To develop an economic, practical and readily available animal model for preclinical testing of urethral bulking therapies, as well as to establish feasible experimental methods that allow for complete analysis of hard microparticle bulking agents. Alumina ceramic beads suspended in hyaluronic acid were injected into the proximal urethra of 15 female rats under an operating microscope. We assessed overall lower urinary tract function, bulking material intraurethral integrity and local host tissue response over time. Microphotographs were taken during injection and again 6 months postoperatively, before urethral harvest. Urinary flow rate and voiding frequency were assessed before and after injection. At 6 months, the urethra was removed and embedded in resin. Hard tissue sections were cut using a sawing microtome, and processed for histological analysis using scanning electron microscopy, light microscopy and immunohistochemistry. Microphotographs of the urethra showed complete volume retention of the bulking agent at 6 months. There was no significant difference between average urinary frequency and mean urinary flow rate at 1 and 3 months postinjection as compared with baseline. Scanning electron microscopy proved suitable for evaluation of microparticle size and integrity, as well as local tissue remodeling. Light microscopy and immunohistochemistry allowed for evaluation of an inflammatory host tissue reaction to the bulking agent. The microsurgical injection technique, in vivo physiology and novel hard tissue processing for histology, described in the present study, will allow for future comprehensive preclinical testing of urethral bulking therapy agents containing microparticles made of a hard material. © 2015 The Japanese Urological Association.

A meta-analysis of the abscopal effect in preclinical models: Is the biologically effective dose a relevant physical trigger?

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Raffaella Marconi

Full Text Available Preclinical in vivo studies using small animals are considered crucial in translational cancer research and clinical implementation of novel treatments. This is of paramount relevance in radiobiology, especially for any technological developments permitted to deliver high doses in single or oligo-fractionated regimens, such as stereotactic ablative radiotherapy (SABR. In this context, clinical success in cancer treatment needs to be guaranteed, sparing normal tissue and preventing the potential spread of disease or local recurrence. In this work we introduce a new dose-response relationship based on relevant publications concerning preclinical models with regard to delivered dose, fractionation schedule and occurrence of biological effects on non-irradiated tissue, abscopal effects.We reviewed relevant publications on murine models and the abscopal effect in radiation cancer research following PRISMA methodology. In particular, through a log-likelihood method, we evaluated whether the occurrence of abscopal effects may be related to the biologically effective dose (BED. To this aim, studies accomplished with different tumor histotypes were considered in our analysis including breast, colon, lung, fibrosarcoma, pancreas, melanoma and head and neck cancer. For all the tumors, the α / β ratio was assumed to be 10 Gy, as generally adopted for neoplastic cells.Our results support the hypothesis that the occurrence rate of abscopal effects in preclinical models increases with BED. In particular, the probability of revealing abscopal effects is 50% when a BED of 60 Gy is generated.Our study provides evidence that SABR treatments associated with high BEDs could be considered an effective strategy in triggering the abscopal effect, thus shedding light on the promising outcomes revealed in clinical practice.

[Operative treatment strategies for multiple trauma patients : early total care versus damage control].

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Klüter, T; Lippross, S; Oestern, S; Weuster, M; Seekamp, A

2013-09-01

The treatment of multiple trauma patients is a great challenge for an interdisciplinary team. After preclinical care and subsequent treatment in the emergency room the order of the interventions is prioritized depending of the individual risk stratification. For planning the surgery management it is essential to distinguish between absolutely essential operations to prevent life-threatening situations for the patient and interventions with shiftable indications, depending on the general condition of the patient. All interventions need to be done without causing significant secondary damage to prohibit hyperinflammation and systemic inflammatory response syndrome. The challenge consists in determination of the appropriate treatment at the right point in time. In general the early primary intervention, early total care, is differentiated from the damage control concept.

SU-E-I-83: Error Analysis of Multi-Modality Image-Based Volumes of Rodent Solid Tumors Using a Preclinical Multi-Modality QA Phantom

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Lee, Y [University of Kansas Hospital, Kansas City, KS (United States); Fullerton, G; Goins, B [University of Texas Health Science Center at San Antonio, San Antonio, TX (United States)

2015-06-15

Purpose: In our previous study a preclinical multi-modality quality assurance (QA) phantom that contains five tumor-simulating test objects with 2, 4, 7, 10 and 14 mm diameters was developed for accurate tumor size measurement by researchers during cancer drug development and testing. This study analyzed the errors during tumor volume measurement from preclinical magnetic resonance (MR), micro-computed tomography (micro- CT) and ultrasound (US) images acquired in a rodent tumor model using the preclinical multi-modality QA phantom. Methods: Using preclinical 7-Tesla MR, US and micro-CT scanners, images were acquired of subcutaneous SCC4 tumor xenografts in nude rats (3–4 rats per group; 5 groups) along with the QA phantom using the same imaging protocols. After tumors were excised, in-air micro-CT imaging was performed to determine reference tumor volume. Volumes measured for the rat tumors and phantom test objects were calculated using formula V = (π/6)*a*b*c where a, b and c are the maximum diameters in three perpendicular dimensions determined by the three imaging modalities. Then linear regression analysis was performed to compare image-based tumor volumes with the reference tumor volume and known test object volume for the rats and the phantom respectively. Results: The slopes of regression lines for in-vivo tumor volumes measured by three imaging modalities were 1.021, 1.101 and 0.862 for MRI, micro-CT and US respectively. For phantom, the slopes were 0.9485, 0.9971 and 0.9734 for MRI, micro-CT and US respectively. Conclusion: For both animal and phantom studies, random and systematic errors were observed. Random errors were observer-dependent and systematic errors were mainly due to selected imaging protocols and/or measurement method. In the animal study, there were additional systematic errors attributed to ellipsoidal assumption for tumor shape. The systematic errors measured using the QA phantom need to be taken into account to reduce measurement

Students’ evaluation of preclinical simulation for all ceramic preparation (In Faculty of Dentistry Universiti Kebangsaan Malaysia

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Natasya Ahmad Tarib

2008-06-01

Full Text Available The purpose of the study is to evaluate all ceramic crown (ACC preparations those were made by dental undergraduate students during the preclinical sessions. 104 plastic teeth were prepared by 4th year dental undergraduates during the preclinical session for ACC crown examined. The teeth were placed on the frasaco arches and were mounted in the frasaco head. The preparations were examined for the tapering, presence of undercuts, incisal and cingulum reductions as well as preparation of shoulder margin. Preparations were examined using hand instruments and visual. The sample size was 92 plastic teeth. Most of the preparations were acceptable with acceptable placement and types of margins, adequate axial and incisal reductions and acceptable tapered of the axial walls. On the other hand, most of the teeth showed absence of cingulum wall. Most of the crowns prepared by the students were acceptable. It showed that they understood the principles of crown preparation. Cingulum wall preparation has to be given greater emphasis as it is important in the retention and resistance of the restoration.

Methodological Aspects for Preclinical Evaluation of Gadolinium Presence in Brain Tissue: Critical Appraisal and Suggestions for Harmonization-A Joint Initiative.

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Robert, Philippe; Frenzel, Thomas; Factor, Cécile; Jost, Gregor; Rasschaert, Marlène; Schuetz, Gunnar; Fretellier, Nathalie; Boyken, Janina; Idée, Jean-Marc; Pietsch, Hubertus

2018-04-13

Gadolinium (Gd)-based contrast agents (GBCAs) are pharmaceuticals that have been approved for 30 years and used daily in millions of patients worldwide. Their clinical benefits are indisputable. Recently, unexpected long-term presence of Gd in the brain has been reported by numerous retrospective clinical studies and confirmed in preclinical models particularly after linear GBCA (L-GBCA) compared with macrocyclic GBCA (M-GBCA). Even if no clinical consequences of Gd presence in brain tissue has been demonstrated so far, in-depth investigations on potential toxicological consequences and the fate of Gd in the body remain crucial to potentially adapt the clinical use of GBCAs, as done during the nephrogenic systemic fibrosis crisis. Preclinical models are instrumental in the understanding of the mechanism of action as well as the potential safety consequences. However, such models may be associated with risks of biases, often related to the protocol design. Selection of adequate terminology is also crucial. This review of the literature intends to summarize and critically discuss the main methodological aspects for accurate design and translational character of preclinical studies.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Utility of a human FcRn transgenic mouse model in drug discovery for early assessment and prediction of human pharmacokinetics of monoclonal antibodies

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Avery, Lindsay B.; Wang, Mengmeng; Kavosi, Mania S.; Joyce, Alison; Kurz, Jeffrey C.; Fan, Yao-Yun; Dowty, Martin E.; Zhang, Minlei; Zhang, Yiqun; Cheng, Aili; Hua, Fei; Jones, Hannah M.; Neubert, Hendrik; Polzer, Robert J.; O'Hara, Denise M.

2016-01-01

ABSTRACT Therapeutic antibodies continue to develop as an emerging drug class, with a need for preclinical tools to better predict in vivo characteristics. Transgenic mice expressing human neonatal Fc receptor (hFcRn) have potential as a preclinical pharmacokinetic (PK) model to project human PK of monoclonal antibodies (mAbs). Using a panel of 27 mAbs with a broad PK range, we sought to characterize and establish utility of this preclinical animal model and provide guidance for its application in drug development of mAbs. This set of mAbs was administered to both hemizygous and homozygous hFcRn transgenic mice (Tg32) at a single intravenous dose, and PK parameters were derived. Higher hFcRn protein tissue expression was confirmed by liquid chromatography-high resolution tandem mass spectrometry in Tg32 homozygous versus hemizygous mice. Clearance (CL) was calculated using non-compartmental analysis and correlations were assessed to historical data in wild-type mouse, non-human primate (NHP), and human. Results show that mAb CL in hFcRn Tg32 homozygous mouse correlate with human (r2 = 0.83, r = 0.91, p PK studies, enhancement of the early selection of lead molecules, and ultimately a decrease in the time for a drug candidate to reach the clinic. PMID:27232760

The effect of magnification loupes on the performance of preclinical dental students.

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Maggio, Margrit P; Villegas, Hilda; Blatz, Markus B

2011-01-01

optical magnifying devices such as magnification loupes are increasingly used in clinical practice and educational settings. However, scientific evidence to validate their benefits is limited. This study assessed the effect of dental magnification loupes on psychomotor skill acquisition during a preclinical operative dentistry course. the performance of first-year dental students was assessed during an Advanced Simulation Course (AS) using virtual reality-based technology (VRBT) training. The test group consisted of 116 dental students using magnification loupes (+MAG), while students not using them (-MAG, n = 116) served as the control. The following parameters were evaluated: number of successfully passing preparation procedures per course rotation, amount of time per tooth preparation, number of times students needed computer assistance and evaluation, and amount of time spent in the computer assistance and evaluation mode per procedure. Data were collected on each student through VRBT during the preparation procedure and stored on a closed network server computer. Unpaired t tests were used to analyze mean differences between the groups. In addition, student acceptance of magnification loupes was measured and evaluated through survey interpretation. +MAG students completed more preparations, worked faster per procedure, and used the computer-assisted evaluation less frequently and for shorter periods, therefore displaying greater overall performance. The survey revealed a high degree of student acceptance of using magnification. dental magnification loupes significantly enhanced student performance during preclinical dental education and were considered an effective adjunct by the students who used them.

Evaluation of early recognition of viral infections in man. [using specific gravity of lymphocytes

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Kelton, A. A.; Lawton, M. B.

1975-01-01

The potential of Lymphocyte Specific Gravity Distribution (LSGD) as a non-specific procedure for early diagnosis of viral disease in astronauts is considered. Results of experiments and a literature search show that several virus diseases result in distinctive changes in the specific gravity distribution of peripheral blood lymphocytes as a result of disease process and associated immune response. A tentative model is proposed which relates the shape of LSGD to the identity of subpopulations of peripheral lymphocytes in a preclinical viral disease situation.

Feasibility of large-scale screening using N-ERC/mesothelin levels in the blood for the early diagnosis of malignant mesothelioma.

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Imashimizu, Kohta; Shiomi, Kazu; Maeda, Masahiro; Aoki, Naoko; Igarashi, Kiyoko; Suzuki, Fumio; Koizumi, Mitsuru; Suzuki, Kenji; Hino, Okio

2011-05-01

A large-scale screening involving the measurement of N-ERC/mesothelin levels in blood using an ELISA system for the early diagnosis of malignant mesothelioma (MM) was carried out in individuals with a history of employment at construction sites. Approximately 30,000 subjects were screened. Of the 80 subjects with high-risk values, one male patient was diagnosed as having MM based on a PET study and histopathology. This is the first report of the pre-clinical diagnosis of MM based on blood test screening. In addition, plasma levels of N-ERC/mesothelin may be effectively used for monitoring relapse after surgery.

The relevance of preclinical research models for the development of antimigraine drugs: Focus on 5-HT1B/1D and CGRP receptors

DEFF Research Database (Denmark)

Gupta, S.; Villalon, C.M.

2010-01-01

to the relief of migraineurs. Pathophysiological factors culminating into migraine headaches have not yet been completely deciphered and, thus, pose an additional challenge for preclinical research in the absence of any direct experimental marker. Migraine provocation experiments in humans use a head......-score to evaluate migraine, as articulated by the volunteer, which cannot be applied to laboratory animals. Therefore, basic research focuses on different symptoms and putative mechanisms, one at a time or in combination, to validate the hypotheses. Studies in several species, utilizing different preclinical...... incorporating the newer ideas/techniques in order to get better insights into migraine pathophysiology. (C) 2010 Elsevier Inc. All rights reserved...

Ontogeny and reversal of brain circuit abnormalities in a preclinical model of PCOS.

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Silva, Mauro Sb; Prescott, Melanie; Campbell, Rebecca E

2018-04-05

Androgen excess is a hallmark of polycystic ovary syndrome (PCOS), a prevalent yet poorly understood endocrine disorder. Evidence from women and preclinical animal models suggests that elevated perinatal androgens can elicit PCOS onset in adulthood, implying androgen actions in both PCOS ontogeny and adult pathophysiology. Prenatally androgenized (PNA) mice exhibit a robust increase of progesterone-sensitive GABAergic inputs to gonadotropin-releasing hormone (GnRH) neurons implicated in the pathogenesis of PCOS. It is unclear when altered GABAergic wiring develops in the brain, and whether these central abnormalities are dependent upon adult androgen excess. Using GnRH-GFP-transgenic mice, we determined that increased GABA input to GnRH neurons occurs prior to androgen excess and the manifestation of reproductive impairments in PNA mice. These data suggest that brain circuit abnormalities precede the postpubertal development of PCOS traits. Despite the apparent developmental programming of circuit abnormalities, long-term blockade of androgen receptor signaling from early adulthood rescued normal GABAergic wiring onto GnRH neurons, improved ovarian morphology, and restored reproductive cycles in PNA mice. Therefore, androgen excess maintains changes in female brain wiring linked to PCOS features and the blockade of androgen receptor signaling reverses both the central and peripheral PNA-induced PCOS phenotype.

Microenvironmental influence on pre-clinical activity of polo-like kinase inhibition in multiple myeloma: implications for clinical translation.

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Douglas W McMillin

Full Text Available Polo-like kinases (PLKs play an important role in cell cycle progression, checkpoint control and mitosis. The high mitotic index and chromosomal instability of advanced cancers suggest that PLK inhibitors may be an attractive therapeutic option for presently incurable advanced neoplasias with systemic involvement, such as multiple myeloma (MM. We studied the PLK 1, 2, 3 inhibitor BI 2536 and observed potent (IC50<40 nM and rapid (commitment to cell death <24 hrs in vitro activity against MM cells in isolation, as well as in vivo activity against a traditional subcutaneous xenograft mouse model. Tumor cells in MM patients, however, don't exist in isolation, but reside in and interact with the bone microenvironment. Therefore conventional in vitro and in vivo preclinical assays don't take into account how interactions between MM cells and the bone microenvironment can potentially confer drug resistance. To probe this question, we performed tumor cell compartment-specific bioluminescence imaging assays to compare the preclinical anti-MM activity of BI 2536 in vitro in the presence vs. absence of stromal cells or osteoclasts. We observed that the presence of these bone marrow non-malignant cells led to decreased anti-MM activity of BI 2536. We further validated these results in an orthotopic in vivo mouse model of diffuse MM bone lesions where tumor cells interact with non-malignant cells of the bone microenvironment. We again observed that BI 2536 had decreased activity in this in vivo model of tumor-bone microenvironment interactions highlighting that, despite BI 2536's promising activity in conventional assays, its lack of activity in microenvironmental models raises concerns for its clinical development for MM. More broadly, preclinical drug testing in the absence of relevant tumor microenvironment interactions may overestimate potential clinical activity, thus explaining at least in part the gap between preclinical vs. clinical efficacy in MM

Assessment of preclinical students’ academic motivation before and after a three-day academic affair program

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Aung MN

2015-12-01

Full Text Available Myo Nyein Aung,1 Juraiporn Somboonwong,2 Vorapol Jaroonvanichkul,1 Pongsak Wannakrairot3 1Medical Education Unit, 2Quality Management Division and Department of Physiology, 3Academic Affairs Division, Faculty of Medicine, Chulalongkorn University, Bangkok, ThailandBackground: Medical students’ motivation is an important driving factor for academic performance, and therefore medical teachers and educators are often highly interested in this topic. This study evaluated the impact of an academic affair program upon preclinical year medical students’ motivation to study.Design and methods: An intervention study was conducted using a pretest-posttest study design. A total of 296 preclinical year medical students who had just passed their first year and were about to attend their second year at the Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, participated in the study. The intervention comprised of dialogues for personality development, pictorial expression in groups, as well as small group lectures delivered by senior students giving information on how to prepare for the forthcoming classes. Students’ academic motivation was measured before and after the intervention program, applying the transculturally translated Academic Motivation Scale (AMS. Cronbach’s alpha of Thai version AMS was 0.8992. The average scores in seven scales of AMS were compared between the pre- and posttest results, using the Wilcoxon signed-rank test. The differences were confirmed by using the multivariate analysis of variance.Results: Students’ academic motivation increased after participation in the three-day academic program. There was also a significant increase in introjected extrinsic motivation, which can enhance the students’ self-esteem and feeling of self-worth (P<0.001. Moreover, intrinsic motivation toward accomplishment increased significantly (P<0.001. This is related to the enjoyment of passing academic milestones, and a step

Preclinical screening for retinopathy of prematurity risk using IGF1 levels at 3 weeks post-partum.

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Alejandro Pérez-Muñuzuri

Full Text Available Following current recommendations for preventing retinopathy of prematurity (ROP involves screening a large number of patients. We performed a prospective study to establish a useful screening system for ROP prediction and we have determined that measuring serum levels of IGF1 at week three and the presence of sepsis have a high predictive value for the subsequent development of ROP. A total of 145 premature newborn, with birthweight <1500 g and/or <32 weeks gestational age, were enrolled. 26.9% of them showed some form of retinopathy. A significant association was found between the development of retinopathy and each of the following variables: early gestational age, low birthweight, requiring mechanical ventilation, oxygen treatment, intracranial haemorrhage, sepsis during the first three weeks, bronchopulmonary dysplasia, the need for erythrocyte transfusion, erythropoietin treatment, and low levels of serum IGF1 in the third week. A multiple logistic regression analysis was used to obtain curves for the probability of developing ROP, based on the main factors linked with ROP, namely serum levels of IGF1 and presence of sepsis. Such preclinical screening has the ability to identify patients with high-risk of developing retinopathy and should lead to better prediction for ROP, while at the same time optimising the use of clinical resources, both human and material.

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

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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.

The preclinical pharmacological study of dopamine transporter imaging agnet (99mTc)trodat-1

International Nuclear Information System (INIS)

Fang, P.; Wan, W.; Wu, C.; Liu, Z.; Wang, T.; Chen, S.; Chen, Z.; Zhou, X.

2000-01-01

To develop 99m Tc labeled dopamine transporter (DAT) imaging agent 99m Tc-TRODAT-1 (TRODAT-1:2 β-[[N,N'-bis(2-mercaptoethyl)ethylenediamino]methl], 3 β-(4-chlorophenyl)tropane], used in SPECT, for evaluating changes of DAT in patients with Parkinson's disease(PD). Using Stannous as reducing agent, and the present of Na-glucoheptonate, 99m Tc-TRODAT-1 was successfully prepared. Preclinical pharmacological studies have been performed in rats. C57BL mice, normal and PD model monkeys and volunteers. Radiochemical purity of 99m Tc-TRODAT-1 was over 90%, and stable for 6 hours. The specific uptake in striatum was significantly diminished from 3.45 to 0.12 at 3 h by pretreated rats with a dose of competing DAT ligand β-CIT (1 mg/kg). Autoradiographic images in C57BL mice shows that the specific uptake has a good linear relationship with the quantity of neural-toxin (MPTP) which was given to the animals (r=0.9792). Images of normal monkey's brain exhibited excellent localization in basal ganglia region, where dopamine neurons were concentrated, and the ratios of ST/CB were 1.56-2.0. In hemiparkinsonian model monkeys, the ratio of normal ST/CB and lesioned ST/CB were 1.56 and 0.94, respectively. Brain image studies in volunteers indicated that uptake and retention in the basal ganglia, the ratio of normal striatal to lesioned one was 1.15 measured by SPECT imaging at 2 h. The result of images was consistent with the clinical symptoms. Above-mentioned results showed that 99m Tc-TRODAT-1 can be accumulated in the striatal area, where DAT are concentrated, high quality images were obtained. It is suggested that 99m Tc-TRODAT-1 might turn to be a safe and effective tracer for monitoring the change in DAT associated with various neurodegenerative diseases

Gas transport during in vitro and in vivo preclinical testing of inert gas therapies

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Ira Katz

2016-01-01

Full Text Available New gas therapies using inert gases such as xenon and argon are being studied, which require in vitro and in vivo preclinical experiments. Examples of the kinetics of gas transport during such experiments are analyzed in this paper. Using analytical and numerical models, we analyze an in vitro experiment for gas transport to a 96 cell well plate and an in vivo delivery to a small animal chamber, where the key processes considered are the wash-in of test gas into an apparatus dead volume, the diffusion of test gas through the liquid media in a well of a cell test plate, and the pharmacokinetics in a rat. In the case of small animals in a chamber, the key variable controlling the kinetics is the chamber wash-in time constant that is a function of the chamber volume and the gas flow rate. For cells covered by a liquid media the diffusion of gas through the liquid media is the dominant mechanism, such that liquid depth and the gas diffusion constant are the key parameters. The key message from these analyses is that the transport of gas during preclinical experiments can be important in determining the true dose as experienced at the site of action in an animal or to a cell.

Drug release, preclinical and clinical pharmacokinetics relationships of alginate pellets prepared by melt technology.

Science.gov (United States)

Bose, Anirbandeep; Harjoh, Nurulaini; Pal, Tapan Kumar; Dan, Shubhasis; Wong, Tin Wui

2016-01-01

Alginate pellets prepared by the aqueous agglomeration technique experience fast drug dissolution due to the porous pre-formed calcium alginate microstructure. This study investigated in vitro drug release, preclinical and clinical pharmacokinetics relationships of intestinal-specific calcium acetate-alginate pellets against calcium-free and calcium carbonate-alginate pellets. Alginate pellets were prepared by solvent-free melt pelletization instead of aqueous agglomeration technique using chlorpheniramine maleate as model drug. A fast in situ calcium acetate dissolution in pellets resulted in rapid pellet breakup, soluble Ca(2+) crosslinking of alginate fragments and drug dissolution retardation at pH 1.2, which were not found in other pellet types. The preclinical drug absorption rate was lower with calcium acetate loaded than calcium-free alginate pellets. In human subjects, however, the extent and the rate of drug absorption were higher from calcium acetate-loaded pellets than calcium-free alginate pellets. The fine, dispersible and weakly gastric mucoadhesive calcium alginate pellets underwent fast human gastrointestinal transit. They released the drug at a greater rate than calcium-free pellets in the intestine, thereby promoting drug bioavailability. Calcium acetate was required as a disintegrant more than as a crosslinking agent clinically to promote pellet fragmentation, fast gastrointestinal transit and drug release in intestinal medium, and intestinal-specific drug bioavailability.

An assessment of the utilization of the preclinical rodent model literature in clinical trials of putative therapeutics for the treatment of alcohol use disorders.

Science.gov (United States)

Barajaz, Ashley M; Kliethermes, Christopher L

2017-12-01

Rodent models of Alcohol Use Disorders (AUD) are used extensively by preclinical researchers to develop new therapeutics for the treatment of AUD. Although these models play an important role in the development of novel, targeted therapeutics, their role in bringing therapeutics to clinical trials is unclear, as off-label use of existing medications not approved for the treatment of AUD is commonly seen in the clinic and clinical trials. In the current study, we used the Clinicaltrials.gov database to obtain a list of drugs that have been tested for efficacy in a clinical trial between 1997 and 2017. We then conducted a set of literature searches to determine which of the 98 unique drugs we identified had shown efficacy in a rodent model of an AUD prior to being tested in a clinical trial. We found that slightly less than half of the drugs tested in clinical trials (48%) had shown prior efficacy in any rodent model of an AUD, while the remaining 52% of drugs were used off-label, or in some cases, following non-published studies. This study raises the question of how clinical researchers incorporate results from preclinical studies in the decision to bring a drug to a clinical trial. Our results underscore the need for ongoing communication among preclinical and clinical researchers. Copyright © 2017 Elsevier B.V. All rights reserved.

Hematopoietic cell crisis: An early stage of evolving myeloid leukemia following radiation exposure

International Nuclear Information System (INIS)

Seed, T.M.

1990-01-01

Under select radiological conditions, chronic radiation exposure elicits a high incidence of myeloproliferative disease, principally myeloid leukemia (ML), in beagles. Previously we demonstrated that for full ML expression, a four-stage preclinical sequence is required, namely (1) suppression, (2) recovery, (3) accommodation, and (4) preleukemic transition. Within this pathological sequence, a critical early event has been identified as the acquisition of radioresistance by hematopoietic progenitors that serves to mediate a newfound regenerative hematopoietic capacity. As such, this event ''sets the stage'' for preleukemic progression by initiating progression from preclinical phase 1 to 2. Due to the nature of target cell suppression, the induction of crisis, and the outgrowth of progenitors with altered phenotypes, this preleukemic event resembles the ''immortalization'' step of the in vitro transformation sequence following induction with either physical and chemical carcinogens. The radiological, temporal, and biological dictates governing this event have been extensively evaluated and will be discussed in light of their role in the induction and progression of chronic radiation leukemia. 35 refs., 2 tabs

Hematopoietic cell crisis: An early stage of evolving myeloid leukemia following radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Seed, T.M.

1990-01-01

Under select radiological conditions, chronic radiation exposure elicits a high incidence of myeloproliferative disease, principally myeloid leukemia (ML), in beagles. Previously we demonstrated that for full ML expression, a four-stage preclinical sequence is required, namely (1) suppression, (2) recovery, (3) accommodation, and (4) preleukemic transition. Within this pathological sequence, a critical early event has been identified as the acquisition of radioresistance by hematopoietic progenitors that serves to mediate a newfound regenerative hematopoietic capacity. As such, this event sets the stage'' for preleukemic progression by initiating progression from preclinical phase 1 to 2. Due to the nature of target cell suppression, the induction of crisis, and the outgrowth of progenitors with altered phenotypes, this preleukemic event resembles the immortalization'' step of the in vitro transformation sequence following induction with either physical and chemical carcinogens. The radiological, temporal, and biological dictates governing this event have been extensively evaluated and will be discussed in light of their role in the induction and progression of chronic radiation leukemia. 35 refs., 2 tabs.

Can cancer researchers accurately judge whether preclinical reports will reproduce?

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Daniel Benjamin

2017-06-01

Full Text Available There is vigorous debate about the reproducibility of research findings in cancer biology. Whether scientists can accurately assess which experiments will reproduce original findings is important to determining the pace at which science self-corrects. We collected forecasts from basic and preclinical cancer researchers on the first 6 replication studies conducted by the Reproducibility Project: Cancer Biology (RP:CB to assess the accuracy of expert judgments on specific replication outcomes. On average, researchers forecasted a 75% probability of replicating the statistical significance and a 50% probability of replicating the effect size, yet none of these studies successfully replicated on either criterion (for the 5 studies with results reported. Accuracy was related to expertise: experts with higher h-indices were more accurate, whereas experts with more topic-specific expertise were less accurate. Our findings suggest that experts, especially those with specialized knowledge, were overconfident about the RP:CB replicating individual experiments within published reports; researcher optimism likely reflects a combination of overestimating the validity of original studies and underestimating the difficulties of repeating their methodologies.

The importance of clinical pharmacokinetic–pharmacodynamic studies in unraveling the determinants of early and late tuberculosis outcomes

OpenAIRE

McCallum, Andrew; Sloan, Derek

2017-01-01

Tuberculosis remains a major infectious cause of morbidity and mortality worldwide. Current antibiotic regimens, constructed prior to the development of modern pharmacokinetic-pharmacodynamic (PK–PD) tools, are based on incomplete understanding of exposure–response relationships in drug susceptible and multidrug resistant tuberculosis. Preclinical and population PK data suggest that clinical PK–PD studies may enable therapeutic drug monitoring for some agents and revised dosingf or others. Fu...

Targeting the epidermal growth factor receptor in radiotherapy: radiobiological mechanisms, preclinical and clinical results

International Nuclear Information System (INIS)

Baumann, Michael; Krause, Mechthild

2004-01-01

Background and purpose: Inhibition of the epidermal growth factor receptor (EGFR) is a fastly developing field in preclinical and clinical cancer research. This review presents the current status of knowledge and discusses radiobiological mechanisms which may underly the efficacy of EGFR inhibitors combined with irradiation. Materials and methods: Preclinical and clinical results on combined targeting of the EGFR and irradiation from the literature and from this laboratory are reviewed. Focus is given to the radiobiological rationale of this approach and to endpoints of experimental radiotherapy. Results: Overexpression of the EGFR is associated with decreased local tumour control after radiotherapy, especially when the overall treatment time is long. Inhibition of the EGFR either alone or in combination with irradiation decreases the growth rate of tumours expressing this receptor. Preclinical data provide proof-of-principle that local tumour control may be improved by combining irradiation with C225 mAb. In a randomised phase III clinical trial, simultaneous irradiation and treatment with the EGFR antibody Cetuximab (Erbitux[reg]; C225) in head and neck cancer patients resulted in significantly improved locoregional tumour control and survival compared to curative irradiation alone. Acute skin reactions increased in the experimental arm. The underlying mechanisms of enhanced radiation effects of combined EGFR inhibition with irradiation and of the partly conflicting results in different studies are poorly understood. There is increasing evidence, that important intertumoral heterogeneity in the response to EGFR inhibition alone and combined with irradiation exists, which appears to be at least partly dependent on specific mutations of the receptor as well as of molecules that are involved in the intracellular signal transduction pathway. Conclusions and outlook: Further investigations at all levels of the translational research chain exploring the mechanisms of

Molecular characterization of murine models of squamous carcinomas of preclinical application

International Nuclear Information System (INIS)

Bornachea Gomez, O.; Berdugo Zamora, A.

2015-01-01

The epidermis is a stratified epithelium affected by numerous pathologies, including cancer, being the tumors originated in this tissue more than half of the epithelial tumors diagnosed every year. Animal models are an essential tool for cancer research, as they provide information to understand how a homologous gene may cause or contribute to the disease in humans. The p53 CE and Rb CE; p53 CE murine models develop undifferentiated epidermal tumors with high metastatic potential that show a strong transcriptional similarity to many human tumors with poor prognosis. Numerous studies have associated the p53 tumor suppressor with deregulation of microRNAs involved in the epithelial-mesenchymal transition (EMT) and metastasis processes. Furthermore, tumors in p53 EC models show an early repression of p63 whose predominant isoform in keratinocytes of the basal layer is Np63. Our results indicate that miR21 helps to provide metastatic capacity to p53-deficient mouse skin tumors. The increased expression of miR21 correlates with active signaling pathways that can be inhibited pharmacologically. Moreover, miR21 expression is elevated in human metastatic lung tumors with poor prognosis. Besides, we also show that ?Np63? expression in p53-deficient cells partially reduces the metastatic behavior, most probably through the modulation microRNAs and transcription factors involved in the EMT process. These facts point to p53-deficient epidermal animal models as excellent candidates for preclinical analysis of human metastatic tumors characterized by TP53 alterations. Finally we developed a model in which the three members of the retinoblastoma family are ablated in the basal cells of stratified epithelia in a tamoxifen inducible manner: Rb1F/F ; Rbl2F/F;Rbl1-/-;K14CreErT2 (TKO). Previously our laboratory had shown that, in the absence of pRb, malignant conversion occurred when p53 is lost. At high doses of tamoxifen these animals show early lethality. When we adjust the dose

Benefits of Case-Based versus Traditional Lecture-Based Instruction in a Preclinical Removable Prosthodontics Course.

Science.gov (United States)

Samuelson, David B; Divaris, Kimon; De Kok, Ingeborg J

2017-04-01

This study compared the acceptability and relative effectiveness of case-based learning (CBL) versus traditional lecture-based (LB) instruction in a preclinical removable prosthodontics course in the University of North Carolina at Chapel Hill School of Dentistry DDS curriculum. The entire second-year class (N=82) comprised this crossover study's sample. Assessments of baseline comprehension and confidence in removable partial denture (RPD) treatment planning were conducted at the beginning of the course. Near the end of the course, half of the class received CBL and LB instruction in an RPD module in alternating sequence, with students serving as their own control group. Assessments of perceived RPD treatment planning efficacy, comprehension, and instruction method preference were administered directly after students completed the RPD module and six months later. Analyses of variance accounting for period, carryover, and sequence effects were used to determine the relative effects of each approach using a peffects, CBL was also associated with higher gains in RPD treatment planning comprehension (p=0.04) and perceived efficacy (p=0.01) compared to LB instruction. These gains diminished six months after the course-a finding based on a 49% follow-up response rate. Overall, the students overwhelmingly preferred CBL to LB instruction, and the findings suggest small albeit measurable educational benefits associated with CBL. This study's findings support the introduction and further testing of CBL in the preclinical dental curriculum, in anticipation of possible future benefits evident during clinical training.

Preclinical models for obesity research

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Perry Barrett

2016-11-01

Full Text Available A multi-dimensional strategy to tackle the global obesity epidemic requires an in-depth understanding of the mechanisms that underlie this complex condition. Much of the current mechanistic knowledge has arisen from preclinical research performed mostly, but not exclusively, in laboratory mouse and rat strains. These experimental models mimic certain aspects of the human condition and its root causes, particularly the over-consumption of calories and unbalanced diets. As with human obesity, obesity in rodents is the result of complex gene–environment interactions. Here, we review the traditional monogenic models of obesity, their contemporary optogenetic and chemogenetic successors, and the use of dietary manipulations and meal-feeding regimes to recapitulate the complexity of human obesity. We critically appraise the strengths and weaknesses of these different models to explore the underlying mechanisms, including the neural circuits that drive behaviours such as appetite control. We also discuss the use of these models for testing and screening anti-obesity drugs, beneficial bio-actives, and nutritional strategies, with the goal of ultimately translating these findings for the treatment of human obesity.

Vitamins in Pancreatic Cancer: A Review of Underlying Mechanisms and Future Applications12

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Davis-Yadley, Ashley H; Malafa, Mokenge P

2015-01-01

Although there is increasing evidence that vitamins influence pancreatic adenocarcinoma biology and carcinogenesis, a comprehensive review is lacking. In this study, we performed a PubMed literature search to review the anticancer mechanisms and the preclinical and clinical studies that support the development of the bioactive vitamins A, C, D, E, and K in pancreatic cancer intervention. Preclinical studies have shown promising results for vitamin A in pancreatic cancer prevention, with clinical trials showing intriguing responses in combination with immunotherapy. For vitamin C, preclinical studies have shown slower tumor growth rates and/or increased survival when used alone or in combination with gemcitabine, with clinical trials with this combination revealing decreased primary tumor sizes and improved performance status. Preclinical studies with vitamin D analogues have shown potent antiproliferative effects and repression of migration and invasion of pancreatic cancer cells, with a clinical trial showing increased time to progression when calciferol was added to docetaxel. For vitamin E, preclinical studies have shown that δ-tocotrienol and γ-tocotrienol inhibited tumor cell growth and survival and augmented gemcitabine activity. Early-phase clinical trials with δ-tocotrienol are ongoing. Vitamin K demonstrates activation of apoptosis and inhibition of cellular growth in pancreatic tumor cells; however, there are no clinical studies available for further evaluation. Although preclinical and clinical studies are encouraging, randomized controlled trials with endpoints based on insights gained from mechanistic and preclinical studies and early-phase clinical trials are required to determine the efficacy of bioactive vitamin interventions in pancreatic cancer. PMID:26567201

Preclinical diagnosis and emergency medical care in case of radiation accidents

International Nuclear Information System (INIS)

Ohlenschlaeger, L.

1990-01-01

Reference is made to preclinical diagnosis and emergency medical care at the site of a potential radiation accident. Possibilities and limits, respectively, of the medical measures are shown. Cooperation between the experts of the technical and medical rescue services is described. Exposition to radiation for the emergency medical staff resulting from the medical care of contaminated persons, is negligible if the personal precautions are observed. (orig.) [de

Omics Meets Biology: Application to the Design and Preclinical Assessment of Antivenoms

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Juan J. Calvete

2014-12-01

Full Text Available Snakebite envenoming represents a neglected tropical disease that has a heavy public health impact worldwide, mostly affecting poor people involved in agricultural activities in Africa, Asia, Latin America and Oceania. A key issue that complicates the treatment of snakebite envenomings is the poor availability of the only validated treatment for this disease, antivenoms. Antivenoms can be an efficacious treatment for snakebite envenoming, provided they are safe, effective, affordable, accessible and administered appropriately. The shortage of antivenoms in various regions, particularly in Sub-Saharan Africa and some parts of Asia, can be significantly alleviated by optimizing the use of current antivenoms and by the generation of novel polyspecific antivenoms having a wide spectrum of efficacy. Complementing preclinical testing of antivenom efficacy using in vivo and in vitro functional neutralization assays, developments in venomics and antivenomics are likely to revolutionize the design and preclinical assessment of antivenoms by being able to test new antivenom preparations and to predict their paraspecific neutralization to the level of species-specific toxins.

How Preclinical Models Evolved to Resemble the Diagnostic Criteria of Drug Addiction.

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Belin-Rauscent, Aude; Fouyssac, Maxime; Bonci, Antonello; Belin, David

2016-01-01

Drug addiction is a complex neuropsychiatric disorder that affects a subset of the individuals who take drugs. It is characterized by maladaptive drug-seeking habits that are maintained despite adverse consequences and intense drug craving. The pathophysiology and etiology of addiction is only partially understood despite extensive research because of the gap between current preclinical models of addiction and the clinical criteria of the disorder. This review presents a brief overview, based on selected methodologies, of how behavioral models have evolved over the last 50 years to the development of recent preclinical models of addiction that more closely mimic diagnostic criteria of addiction. It is hoped that these new models will increase our understanding of the complex neurobiological mechanisms whereby some individuals switch from controlled drug use to compulsive drug-seeking habits and relapse to these maladaptive habits. Additionally, by paving the way to bridge the gap that exists between biobehavioral research on addiction and the human situation, these models may provide new perspectives for the development of novel and effective therapeutic strategies for drug addiction. Published by Elsevier Inc.

Applications of the Preclinical Molecular Imaging in Biomedicine: Gene Therapy

International Nuclear Information System (INIS)

Collantes, M.; Peñuelas, I.

2014-01-01

Gene therapy constitutes a promising option for efficient and targeted treatment of several inherited disorders. Imaging techniques using ionizing radiation as PET or SPECT are used for non-invasive monitoring of the distribution and kinetics of vector-mediated gene expression. In this review the main reporter gene/reporter probe strategies are summarized, as well as the contribution of preclinical models to the development of this new imaging modality previously to its application in clinical arena. [es

Multimodal imaging of bone metastases: From preclinical to clinical applications

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Stephan Ellmann

2015-10-01

Full Text Available Metastases to the skeletal system are commonly observed in cancer patients, highly affecting the patients' quality of life. Imaging plays a major role in detection, follow-up, and molecular characterisation of metastatic disease. Thus, imaging techniques have been optimised and combined in a multimodal and multiparametric manner for assessment of complementary aspects in osseous metastases. This review summarises both application of the most relevant imaging techniques for bone metastasis in preclinical models and the clinical setting.

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

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Maha M Eissa

Full Text Available 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

Preclinical Alzheimer disease and risk of falls.

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Stark, Susan L; Roe, Catherine M; Grant, Elizabeth A; Hollingsworth, Holly; Benzinger, Tammie L; Fagan, Anne M; Buckles, Virginia D; Morris, John C

2013-07-30

We determined the rate of falls among cognitively normal, community-dwelling older adults, some of whom had presumptive preclinical Alzheimer disease (AD) as detected by in vivo imaging of fibrillar amyloid plaques using Pittsburgh compound B (PiB) and PET and/or by assays of CSF to identify Aβ₄₂, tau, and phosphorylated tau. We conducted a 12-month prospective cohort study to examine the cumulative incidence of falls. Participants were evaluated clinically and underwent PiB PET imaging and lumbar puncture. Falls were reported monthly using an individualized calendar journal returned by mail. A Cox proportional hazards model was used to test whether time to first fall was associated with each biomarker and the ratio of CSF tau/Aβ₄₂ and CSF phosphorylated tau/Aβ₄₂, after adjustment for common fall risk factors. The sample (n = 125) was predominately female (62.4%) and white (96%) with a mean age of 74.4 years. When controlled for ability to perform activities of daily living, higher levels of PiB retention (hazard ratio = 2.95 [95% confidence interval 1.01-6.45], p = 0.05) and of CSF biomarker ratios (p risk factor for falls in older adults. This study suggests that subtle noncognitive changes that predispose older adults to falls are associated with AD and may precede detectable cognitive changes.

Prefrontal cortical gamma-aminobutyric acid transmission and cognitive function: drawing links to schizophrenia from preclinical research.

Science.gov (United States)

Tse, Maric T; Piantadosi, Patrick T; Floresco, Stan B

2015-06-01

Cognitive dysfunction in schizophrenia is one of the most pervasive and debilitating aspects of the disorder. Among the numerous neural abnormalities that may contribute to schizophrenia symptoms, perturbations in markers for the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), particularly within the frontal lobes, are some of the most reliable alterations observed at postmortem examination. However, how prefrontal GABA dysfunction contributes to cognitive impairment in schizophrenia remains unclear. We provide an overview of postmortem GABAergic perturbations in the brain affected by schizophrenia and describe circumstantial evidence linking these alterations to cognitive dysfunction. In addition, we conduct a survey of studies using neurodevelopmental, genetic, and pharmacologic rodent models that induce schizophrenia-like cognitive impairments, highlighting the convergence of these mechanistically distinct approaches to prefrontal GABAergic disruption. We review preclinical studies that have directly targeted prefrontal cortical GABAergic transmission using local application of GABAA receptor antagonists. These studies have provided an important link between GABA transmission and cognitive dysfunction in schizophrenia because they show that reducing prefrontal inhibitory transmission induces various cognitive, emotional, and dopaminergic abnormalities that resemble aspects of the disorder. These converging clinical and preclinical findings provide strong support for the idea that perturbations in GABA signaling drive certain forms of cognitive dysfunction in schizophrenia. Future studies using this approach will yield information to refine further a putative "GABA hypothesis" of schizophrenia. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Near-peers improve patient safety training in the preclinical curriculum.

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Raty, Sally R; Teal, Cayla R; Nelson, Elizabeth A; Gill, Anne C

2017-01-01

Accrediting bodies require medical schools to teach patient safety and residents to develop teaching skills in patient safety. We created a patient safety course in the preclinical curriculum and used continuous quality improvement to make changes over time. To assess the impact of resident teaching on student perceptions of a Patient Safety course. Using the Institute for Healthcare Improvement patient safety curriculum as a frame, the course included the seven IHI modules, large group lectures and small group facilitated discussions. Applying a social action methodology, we evaluated the course for four years (Y1-Y4). In Y1, Y2, Y3 and Y4, we distributed a course evaluation to each student (n = 184, 189, 191, and 184, respectively) and the response rate was 96, 97, 95 and 100%, respectively. Overall course quality, clarity of course goals and value of small group discussions increased in Y2 after the introduction of residents as small group facilitators. The value of residents and the overall value of the course increased in Y3 after we provided residents with small group facilitation training. Preclinical students value the interaction with residents and may perceive the overall value of a course to be improved based on near-peer involvement. Residents gain valuable experience in small group facilitation and leadership.

A phase I/II trial of AT9283, a selective inhibitor of aurora kinase in children with relapsed or refractory acute leukemia: challenges to run early phase clinical trials for children with leukemia.

Science.gov (United States)

Vormoor, B; Veal, G J; Griffin, M J; Boddy, A V; Irving, J; Minto, L; Case, M; Banerji, U; Swales, K E; Tall, J R; Moore, A S; Toguchi, M; Acton, G; Dyer, K; Schwab, C; Harrison, C J; Grainger, J D; Lancaster, D; Kearns, P; Hargrave, D; Vormoor, J

2017-06-01

Aurora kinases regulate mitosis and are commonly overexpressed in leukemia. This phase I/IIa study of AT9283, a multikinase inhibitor, was designed to identify maximal tolerated doses, safety, pharmacokinetics, and pharmacodynamic activity in children with relapsed/refractory acute leukemia. The trial suffered from poor recruitment and terminated early, therefore failing to identify its primary endpoints. AT9283 caused tolerable toxicity, but failed to show clinical responses. Future trials should be based on robust preclinical data that provide an indication of which patients may benefit from the experimental agent, and recruitment should be improved through international collaborations and early combination with established treatment strategies. © 2016 Wiley Periodicals, Inc.

Bioluminescent imaging: a critical tool in pre-clinical oncology research.

LENUS (Irish Health Repository)

O'Neill, Karen

2010-02-01

Bioluminescent imaging (BLI) is a non-invasive imaging modality widely used in the field of pre-clinical oncology research. Imaging of small animal tumour models using BLI involves the generation of light by luciferase-expressing cells in the animal following administration of substrate. This light may be imaged using an external detector. The technique allows a variety of tumour-associated properties to be visualized dynamically in living models. The increasing use of BLI as a small-animal imaging modality has led to advances in the development of xenogeneic, orthotopic, and genetically engineered animal models expressing luciferase genes. This review aims to provide insight into the principles of BLI and its applications in cancer research. Many studies to assess tumour growth and development, as well as efficacy of candidate therapeutics, have been performed using BLI. More recently, advances have also been made using bioluminescent imaging in studies of protein-protein interactions, genetic screening, cell-cycle regulators, and spontaneous cancer development. Such novel studies highlight the versatility and potential of bioluminescent imaging in future oncological research.

Laparoscopy training in surgical education: the utility of incorporating a structured preclinical laparoscopy course into the traditional apprenticeship method.

Science.gov (United States)

De Win, Gunter; Van Bruwaene, Siska; Aggarwal, Rajesh; Crea, Nicola; Zhang, Zhewen; De Ridder, Dirk; Miserez, Marc

2013-01-01

To investigate whether preclinical laparoscopy training offers a benefit over standard apprenticeship training and apprenticeship training in combination with simulation training. This randomized controlled trial consisted of 3 groups of first-year surgical registrars receiving a different teaching method in laparoscopic surgery. The KU LEUVEN Faculty of Medicine is the largest medical faculty in Belgium. Thirty final-year medical students starting a general surgical career in the next academic year. Thirty final-year medical students were randomized into 3 groups, which differed in the way they were exposed to laparoscopic simulation training but were comparable in regard to ambidexterity, sex, age, and laparoscopic psychomotoric skills. The control group received only clinical training during surgical residentship, whereas the interval group received clinical training in combination with simulation training. The registrars were allowed to do deliberate practice. The Centre for Surgical Technologies Preclinical Training Programme (CST PTP) group received a preclinical simulation course during the final year as medical students, but was not exposed to any extra simulation training during surgical residentship. At the beginning of surgical residentship and 6 months later, all subjects performed a standardized suturing task and a laparoscopic cholecystectomy in a POP Trainer. All procedures were recorded together with time and motion tracking parameters. All videos were scored by a blinded observer using global rating scales. At baseline the 3 groups were comparable. At 6 months, for suturing, the CST PTP group was better than both the other groups with respect to time, checklist, and amount of movements. The interval group was better than the control group on only the time and checklist score. For the cholecystectomy evaluation, there was a statistical difference between the CST PTP study group and both other groups on all evaluation scales in favor of the CST PTP

At the Crossroads of Clinical and Preclinical Research for Muscular Dystrophy-Are We Closer to Effective Treatment for Patients?

Science.gov (United States)

Gawlik, Kinga I

2018-05-16

Among diseases affecting skeletal muscle, muscular dystrophy is one of the most devastating and complex disorders. The term 'muscular dystrophy' refers to a heterogeneous group of genetic diseases associated with a primary muscle defect that leads to progressive muscle wasting and consequent loss of muscle function. Muscular dystrophies are accompanied by numerous clinical complications and abnormalities in other tissues that cause extreme discomfort in everyday life. The fact that muscular dystrophy often takes its toll on babies and small children, and that many patients die at a young age, adds to the cruel character of the disease. Clinicians all over the world are facing the same problem: they have no therapy to offer except for symptom-relieving interventions. Patients, their families, but also clinicians, are in urgent need of an effective cure. Despite advances in genetics, increased understanding of molecular mechanisms underlying muscle disease, despite a sweeping range of successful preclinical strategies and relative progress of their implementation in the clinic, therapy for patients is currently out of reach. Only a greater comprehension of disease mechanisms, new preclinical studies, development of novel technologies, and tight collaboration between scientists and physicians can help improve clinical treatment. Fortunately, inventiveness in research is rapidly extending the limits and setting new standards for treatment design. This review provides a synopsis of muscular dystrophy and considers the steps of preclinical and clinical research that are taking the muscular dystrophy community towards the fundamental goal of combating the traumatic disease.

Study of Early Child Care and Youth Development (SECCYD)

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... Facebook Twitter Pinterest Email Print NICHD Study of Early Child Care and Youth Development (SECCYD) Sunsetted/For Reference ... page is not being updated . The Study of Early Child Care and Youth Development (SECCYD) began as the ...

The Role of Digital 3D Scanned Models in Dental Students' Self-Assessments in Preclinical Operative Dentistry.

Science.gov (United States)

Lee, Cliff; Kobayashi, Hiro; Lee, Samuel R; Ohyama, Hiroe

2018-04-01

The aim of this study was to determine how dental student self-assessment and faculty assessment of operative preparations compared for conventional visual assessment versus assessment of scanned digital 3D models. In 2016, all third-year students in the Class of 2018 (N=35) at Harvard School of Dental Medicine performed preclinical exams of Class II amalgam preparations (C2AP) and Class III composite preparations (C3CP) and completed self-assessment forms; in 2017, all third-year students in the Class of 2019 (N=34) performed the same exams. Afterwards, the prepared typodont teeth were digitally scanned. Students self-assessed their preparations digitally, and four faculty members graded the preparations conventionally and digitally. The results showed that, overall, the students assessed their preparations higher than the faculty assessments. The mean student-faculty gaps for C2AP and C3CP in the conventional assessments were 11% and 5%, respectively. The mean digital student-faculty gap for C2AP and C3CP were 8% and 2%, respectively. In the conventional assessments, preclinical performance was negatively correlated with the student-faculty gap (r=-0.47, pStudents in the bottom quartile significantly improved their self-assessment accuracy using digital self-assessments over conventional assessments (C2AP 10% vs. 17% and C3CP 3% vs. 10%, respectively). These results suggest that digital assessments offered a significant learning opportunity for students to critically self-assess themselves in operative preclinical dentistry. The lower performing students benefitted the most, improving their assessment ability to the level of the rest of the class.

Efficacy and safety of novel multi-lumen catheter for chronic total occlusions: from preclinical study to first-in-man experience.

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Mitsutake, Yoshiaki; Ebner, Adrian; Yeung, Alan C; Taber, Mark D; Davidson, Charles J; Ikeno, Fumiaki

2015-02-15

To report our initial animal and human experience with a new multi-lumen catheter called MultiCross™ (Roxwood Medical, Inc.) in a porcine coronary model and patients with a chronic total occlusion (CTO). Preclinical safety study was done in the coronary vasculature of a porcine model. In a clinical setting, patients with a CTO of a coronary artery (n = 5) were enrolled. After an initial unsuccessful attempt using a conventional guidewire, operators could use the MultiCross system. The primary efficacy endpoint was successful recanalization (technical success) and the primary safety endpoint was serious adverse events through 30 days post-procedure. The MultiCross catheter was used for all patients after failure of the initial attempt with a guidewire. Successful recanalization was achieved in all CTOs attempted (100%). No patients reported any adverse events at 30 days post-procedure. In this first-in-man experience, the MultiCross catheter has the potential to enhance crossing of CTOs. © 2014 Wiley Periodicals, Inc.

Quantitative angiographic anatomy of the renal arteries and adjacent aorta in the swine for preclinical studies of intravascular catheterization devices.

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Sakaoka, Atsushi; Koshimizu, Masafumi; Nakamura, Shintaro; Matsumura, Kiyoshi

2018-05-10

Swine are the most common animal model in preclinical studies of cardiovascular devices. Because of the recent trend for development of new devices for percutaneous catheterization, especially for the renal arteries (RAs), we examined the quantitative anatomical dimensions of the RAs and adjacent aorta in swine. Angiographic images were analyzed in 66 female Yorkshire/Landrace crossbred swine. The diameter of both the right and left main RA was 5.4 ± 0.6 mm. The length of the right main RA was significantly longer than that of the left (29.8 ± 7.5 mm vs. 20.6 ± 5.4 mm, respectively; Pswine are an appropriate animal model for assessing the safety of, and determining optimal design of, catheter devices for RAs in simulated clinical use. However, there were species differences in the branching angle and adjacent aorta diameter, suggesting that swine models alone are inadequate to assess the delivery performance of catheter devices for RAs.

Discovery of VU0467485/AZ13713945: An M4 PAM Evaluated as a Preclinical Candidate for the Treatment of Schizophrenia.

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Wood, Michael R; Noetzel, Meredith J; Melancon, Bruce J; Poslusney, Michael S; Nance, Kellie D; Hurtado, Miguel A; Luscombe, Vincent B; Weiner, Rebecca L; Rodriguez, Alice L; Lamsal, Atin; Chang, Sichen; Bubser, Michael; Blobaum, Anna L; Engers, Darren W; Niswender, Colleen M; Jones, Carrie K; Brandon, Nicholas J; Wood, Michael W; Duggan, Mark E; Conn, P Jeffrey; Bridges, Thomas M; Lindsley, Craig W

2017-02-09

Herein, we report the structure-activity relationships within a series of potent, selective, and orally bioavailable muscarinic acetylcholine receptor 4 (M 4 ) positive allosteric modulators (PAMs). Compound 6c (VU0467485) possesses robust in vitro M 4 PAM potency across species and in vivo efficacy in preclinical models of schizophrenia. Coupled with an attractive DMPK profile and suitable predicted human PK, 6c (VU0467485) was evaluated as a preclinical development candidate.

Long-term preclinical magnetic resonance imaging alterations in sporadic Creutzfeldt-Jakob disease.

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Zanusso, Gianluigi; Camporese, Giulia; Ferrari, Sergio; Santelli, Luca; Bongianni, Matilde; Fiorini, Michele; Monaco, Salvatore; Manara, Renzo; Cagnin, Annachiara

2016-10-01

An asymptomatic 74-year-old woman, on follow-up for a carotid body tumor, showed magnetic resonance imaging (MRI) focal restricted diffusion confined to the left temporal and occipital cortices. Thirteen months later, diffusion-weighted images revealed a bilateral cortical ribbon sign involving all lobes. After 1 month, the patient developed gait instability and cognitive decline rapidly evolving to severe dementia and death within 3 months. Prion protein gene sequence, molecular, and neuropathological studies confirmed the diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) MM1 subtype. Here we show the kinetics of MRI changes and prion spreading in preclinical sCJD MM1. Ann Neurol 2016;80:629-632. © 2016 American Neurological Association.

Preclinical evaluation of radiolabeled DOTA-derivatized cyclic minigastrin analogs for targeting cholecystokinin receptor expressing malignancies.

NARCIS (Netherlands)

Guggenberg, E. von; Rangger, C.; Sosabowski, J.; Laverman, P.; Reubi, J.C.; Virgolini, I.J.; Decristoforo, C.

2012-01-01

PURPOSE: Targeting of cholecystokinin receptor expressing malignancies such as medullary thyroid carcinoma is currently limited by low in vivo stability of radioligands. To increase the stability, we have developed and preclinically evaluated two cyclic

Curriculum content and assessment of pre-clinical dental skills: A survey of undergraduate dental education in Europe.

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Field, J; Stone, S; Orsini, C; Hussain, A; Vital, S; Crothers, A; Walmsley, D

2018-05-01

Since 1981, the qualifications for various healthcare professionals across the European Union have enjoyed mutual recognition in accordance with the EU Directive 81/1057/EEC. Whilst the directive includes dental practitioners, it is recognised that significant variation exists in curriculum structure, content and scope of practice across institutions. This article aimed to explore pan-European practice in relation to curriculum content, teaching and learning strategies and assessment of pre-clinical dental skills. A request to complete an online questionnaire, in English, was sent electronically to skills leads at all Association of Dental Education in Europe member schools. The questionnaire collected information in relation to institution and country, regulatory requirements to demonstrate safety, details of specific pre-clinical skills courses, learning materials and teaching staff. Forty-eight institutions, from 25 European countries responded. Seven countries (n=7, 28%) reported no requirement to demonstrate student operative safety prior to patient treatment. Several core and operative clinical skills are common to the majority of institutions. The most commonly taught core skills related directly to the clinical environment such as cross-infection control and hand washing. The least common were skills that indirectly related to patient care, such as communication skills and working as a team. There are clear differences within European pre-clinical dental education, and greater efforts are needed to demonstrate that all European students are fit to practice before they start treating patients. Learning outcomes, teaching activities and assessment activities of pre-clinical skills should be shared collaboratively to further standardise curricula. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Uganda Early Generation Seed Study

NARCIS (Netherlands)

Mastenbroek, A.; Ntare, Bonny

2016-01-01

One of the major bottlenecks limiting farmers’ access to good quality seed for food crops in Uganda is the shortage of early generation seed (EGS - breeder and foundation) to produce sufficient quantities of certified and/or quality declared) to satisfy the needs of farmers. A national study was

78 FR 70307 - Guidance for Industry: Preclinical Assessment of Investigational Cellular and Gene Therapy...

Science.gov (United States)

2013-11-25

...] Guidance for Industry: Preclinical Assessment of Investigational Cellular and Gene Therapy Products... Assessment of Investigational Cellular and Gene Therapy Products'' dated November 2013. The guidance document... products reviewed by the Office of Cellular, Tissue and Gene Therapies (OCTGT). The product areas covered...

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

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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

Assessment of clinical reasoning: A Script Concordance test designed for pre-clinical medical students.

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Humbert, Aloysius J; Johnson, Mary T; Miech, Edward; Friedberg, Fred; Grackin, Janice A; Seidman, Peggy A

2011-01-01

The Script Concordance test (SCT) measures clinical reasoning in the context of uncertainty by comparing the responses of examinees and expert clinicians. It uses the level of agreement with a panel of experts to assign credit for the examinee's answers. This study describes the development and validation of a SCT for pre-clinical medical students. Faculty from two US medical schools developed SCT items in the domains of anatomy, biochemistry, physiology, and histology. Scoring procedures utilized data from a panel of 30 expert physicians. Validation focused on internal reliability and the ability of the SCT to distinguish between different cohorts. The SCT was administered to an aggregate of 411 second-year and 70 fourth-year students from both schools. Internal consistency for the 75 test items was satisfactory (Cronbach's alpha = 0.73). The SCT successfully differentiated second- from fourth-year students and both student groups from the expert panel in a one-way analysis of variance (F(2,508) = 120.4; p students from the two schools were not significantly different (p = 0.20). This SCT successfully differentiated pre-clinical medical students from fourth-year medical students and both cohorts of medical students from expert clinicians across different institutions and geographic areas. The SCT shows promise as an easy-to-administer measure of "problem-solving" performance in competency evaluation even in the beginning years of medical education.

Preclinical Evidence for the Efficacy of Ischemic Postconditioning against Renal Ischemia-Reperfusion Injury, a Systematic Review and Meta-Analysis

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Jonker, Simone J.; Menting, Theo P.; Warlé, Michiel C.; Ritskes-Hoitinga, Merel; Wever, Kimberley E.

2016-01-01

Background Renal ischemia-reperfusion injury (IRI) is a major cause of kidney damage after e.g. renal surgery and transplantation. Ischemic postconditioning (IPoC) is a promising treatment strategy for renal IRI, but early clinical trials have not yet replicated the promising results found in animal studies. Method We present a systematic review, quality assessment and meta-analysis of the preclinical evidence for renal IPoC, and identify factors which modify its efficacy. Results We identified 39 publications studying >250 control animals undergoing renal IRI only and >290 animals undergoing renal IRI and IPoC. Healthy, male rats undergoing warm ischemia were used in the vast majority of studies. Four studies applied remote IPoC, all others used local IPoC. Meta-analysis showed that both local and remote IPoC ameliorated renal damage after IRI for the outcome measures serum creatinine, blood urea nitrogen and renal histology. Subgroup analysis indicated that IPoC efficacy increased with the duration of index ischemia. Measures to reduce bias were insufficiently reported. Conclusion High efficacy of IPoC is observed in animal models, but factors pertaining to the internal and external validity of these studies may hamper the translation of IPoC to the clinical setting. The external validity of future animal studies should be increased by including females, comorbid animals, and transplantation models, in order to better inform clinical trial design. The severity of renal damage should be taken into account in the design and analysis of future clinical trials. PMID:26963819

Vaginal wall weakness in parous ewes: a potential preclinical model of pelvic organ prolapse.

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Young, Natharnia; Rosamilia, Anna; Arkwright, John; Lee, Joseph; Davies-Tuck, Miranda; Melendez, Joan; Werkmeister, Jerome; Gargett, Caroline E

2017-07-01

Ewes develop pelvic organ prolapse (POP) and may be a suitable model for preclinical studies evaluating cell-based therapies for POP. The aim of this study was to establish a clinical score of vaginal weakness and to compare POP Quantification System (POP-Q) values in conscious nulliparous and parous ewes and determine whether ewes are a suitable POP model. Ewes (n = 114) were examined while conscious, without sedation, and standing in a V conveyer by adapting the human POP-Q measurement. Ovine POP was defined as descent to the introitus from POP-Q points Aa 3 cm above the introitus on the anterior wall, Ap 3 cm above the introitus on the posterior wall, or increased Ba anterior wall descent above the urethra (≥0). A test-retest showed good inter- and intrarater reliability. There was no evidence of tissue mobility at Aa, Ap, Ba (all -3 cm) in nulliparous ewes (n = 14). In contrast, multiparous ewes had a median of -1 and interquartile range (IQR) (-2 to 0) for Aa, [0 (-1 to 0)] for Ap and [0 (-2.75 to 0)] for Ba (n = 33; P ewes. Ovine vaginal displacement was seen in 50.9 % of parous ewes and was strongly associated with parity (P = 0.003). A modified POP-Q in conscious ewes was established showing that the vaginal wall of parous animals has similar regions of weakness as do women and may be similarly related to parity. Ewes appear to be a representative preclinical model of human vaginal prolapse.

A preclinical murine model for the early detection of radiation-induced brain injury using magnetic resonance imaging and behavioral tests for learning and memory: with applications for the evaluation of possible stem cell imaging agents and therapies.

Science.gov (United States)

Ngen, Ethel J; Wang, Lee; Gandhi, Nishant; Kato, Yoshinori; Armour, Michael; Zhu, Wenlian; Wong, John; Gabrielson, Kathleen L; Artemov, Dmitri

2016-06-01

Stem cell therapies are being developed for radiotherapy-induced brain injuries (RIBI). Magnetic resonance imaging (MRI) offers advantages for imaging transplanted stem cells. However, most MRI cell-tracking techniques employ superparamagnetic iron oxide particles (SPIOs), which are difficult to distinguish from hemorrhage. In current preclinical RIBI models, hemorrhage occurs concurrently with other injury markers. This makes the evaluation of the recruitment of transplanted SPIO-labeled stem cells to injury sites difficult. Here, we developed a RIBI model, with early injury markers reflective of hippocampal dysfunction, which can be detected noninvasively with MRI and behavioral tests. Lesions were generated by sub-hemispheric irradiation of mouse hippocampi with single X-ray beams of 80 Gy. Lesion formation was monitored with anatomical and contrast-enhanced MRI and changes in memory and learning were assessed with fear-conditioning tests. Early injury markers were detected 2 weeks after irradiation. These included an increase in the permeability of the blood-brain barrier, demonstrated by a 92 ± 20 % contrast enhancement of the irradiated versus the non-irradiated brain hemispheres, within 15 min of the administration of an MRI contrast agent. A change in short-term memory was also detected, as demonstrated by a 40.88 ± 5.03 % decrease in the freezing time measured during the short-term memory context test at this time point, compared to that before irradiation. SPIO-labeled stem cells transplanted contralateral to the lesion migrated toward the lesion at this time point. No hemorrhage was detected up to 10 weeks after irradiation. This model can be used to evaluate SPIO-based stem cell-tracking agents, short-term.

The Alzheimer’s Prevention Initiative composite cognitive test score: Sample size estimates for the evaluation of preclinical Alzheimer’s disease treatments in presenilin 1 E280A mutation carriers

Science.gov (United States)

Ayutyanont, Napatkamon; Langbaum, Jessica B.; Hendrix, Suzanne B.; Chen, Kewei; Fleisher, Adam S.; Friesenhahn, Michel; Ward, Michael; Aguirre, Camilo; Acosta-Baena, Natalia; Madrigal, Lucìa; Muñoz, Claudia; Tirado, Victoria; Moreno, Sonia; Tariot, Pierre N.; Lopera, Francisco; Reiman, Eric M.

2014-01-01

Objective There is a need to identify a cognitive composite that is sensitive to tracking preclinical AD decline to be used as a primary endpoint in treatment trials. Method We capitalized on longitudinal data, collected from 1995 to 2010, from cognitively unimpaired presenilin 1 (PSEN1) E280A mutation carriers from the world’s largest known early-onset autosomal dominant AD (ADAD) kindred to identify a composite cognitive test with the greatest statistical power to track preclinical AD decline and estimate the number of carriers age 30 and older needed to detect a treatment effect in the Alzheimer’s Prevention Initiative’s (API) preclinical AD treatment trial. The mean-to-standard-deviation ratios (MSDRs) of change over time were calculated in a search for the optimal combination of one to seven cognitive tests/sub-tests drawn from the neuropsychological test battery in cognitively unimpaired mutation carriers during a two and five year follow-up period, using data from non-carriers during the same time period to correct for aging and practice effects. Combinations that performed well were then evaluated for robustness across follow-up years, occurrence of selected items within top performing combinations and representation of relevant cognitive domains. Results This optimal test combination included CERAD Word List Recall, CERAD Boston Naming Test (high frequency items), MMSE Orientation to Time, CERAD Constructional Praxis and Ravens Progressive Matrices (Set A) with an MSDR of 1.62. This composite is more sensitive than using either the CERAD Word List Recall (MSDR=0.38) or the entire CERAD-Col battery (MSDR=0.76). A sample size of 75 cognitively normal PSEN1-E280A mutation carriers age 30 and older per treatment arm allows for a detectable treatment effect of 29% in a 60-month trial (80% power, p=0.05). Conclusions We have identified a composite cognitive test score representing multiple cognitive domains that has improved power compared to the most

Growth/differentiation factor-5: pre-clinical and clinical evaluations of periodontal regeneration and alveolar augmentation--review.

Science.gov (United States)

Lee, Jaebum; Wikesjö, Ulf M E

2014-08-01

Growth/differentiation factor-5 (GDF-5) plays critical roles in mesenchymal cell differentiation and stimulates human periodontal ligament cell proliferation. Potentially, GDF-5 may also play roles in wound healing including periodontal regeneration and alveolar augmentation. The objective of this review was to provide up-to-date information from pre-clinical/clinical studies evaluating GDF-5 for these indications. A comprehensive search using PubMed and Google search engines was conducted to identify reports on GDF-5 applied to periodontal and alveolar indications. Two reviewers independently screened the titles and abstracts from a total of 479 reports. Full-length articles of 17 pre-clinical and four clinical studies were selected and reviewed. Canine-, porcine- and non-human primate-based models as well as human clinical trials were used in the evaluation of GDF-5 in support of periodontal regeneration and alveolar augmentation. An absorbable collagen sponge (ACS), β-tricalcium phosphate (β-TCP) and a poly(lactic-co-glycolic) acid (PLGA) were evaluated as candidate carriers for GDF-5 using various dose and healing intervals demonstrating significantly enhanced periodontal regeneration/alveolar augmentation including cementum, periodontal ligament and alveolar bone with limited, if any, adverse effects. Growth/differentiation factor-5 supports periodontal regeneration/alveolar augmentation without aberrant healing events documented in qualified pre-clinical models and clinical pilot studies. In perspective, GDF-5 appears a promising technology for periodontal regeneration/alveolar augmentation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Preclinical and Clinical Development of a YFV 17 D-Based Chimeric Vaccine against West Nile Virus

Directory of Open Access Journals (Sweden)

Gustavo H. Dayan

2013-12-01

Full Text Available Substantial success has been achieved in the development and implementation of West Nile (WN vaccines for horses; however, no human WN vaccines are approved. This review focuses on the construction, pre-clinical and clinical characterization of ChimeriVax-WN02 for humans, a live chimeric vaccine composed of a yellow fever (YF 17D virus in which the prM-E envelope protein genes are replaced with the corresponding genes of the WN NY99 virus. Pre-clinical studies demonstrated that ChimeriVax-WN02 was significantly less neurovirulent than YF 17D in mice and rhesus and cynomolgus monkeys. The vaccine elicited neutralizing antibody titers after inoculation in hamsters and monkeys and protected immunized animals from lethal challenge including intracerebral inoculation of high dose of WN NY99 virus. Safety, viremia and immunogenicity of ChimeriVax-WN02 were assessed in one phase I study and in two phase II clinical trials. No safety signals were detected in the three clinical trials with no remarkable differences in incidence of adverse events (AEs between vaccine and placebo recipients. Viremia was transient and the mean viremia levels were low. The vaccine elicited strong and durable neutralizing antibody and cytotoxic T cell responses. WN epidemiology impedes a classical licensure pathway; therefore, innovative licensure strategies should be explored.

An economic evaluation of preclinical testing strategies compared to the compulsory scrapie flock scheme in the control of classical scrapie.