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1

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

PubMed

Industry-sponsored clinical drug studies are associated with publication of outcomes that favor the sponsor, even when controlling for potential bias in the methods used. However, the influence of sponsorship bias has not been examined in preclinical animal studies. We performed a meta-analysis of preclinical statin studies to determine whether industry sponsorship is associated with either increased effect sizes of efficacy outcomes and/or risks of bias in a cohort of published preclinical statin studies. We searched Medline (January 1966-April 2012) and identified 63 studies evaluating the effects of statins on atherosclerosis outcomes in animals. Two coders independently extracted study design criteria aimed at reducing bias, results for all relevant outcomes, sponsorship source, and investigator financial ties. The I(2) statistic was used to examine heterogeneity. We calculated the standardized mean difference (SMD) for each outcome and pooled data across studies to estimate the pooled average SMD using random effects models. In a priori subgroup analyses, we assessed statin efficacy by outcome measured, sponsorship source, presence or absence of financial conflict information, use of an optimal time window for outcome assessment, accounting for all animals, inclusion criteria, blinding, and randomization. The effect of statins was significantly larger for studies sponsored by nonindustry sources (-1.99; 95% CI -2.68, -1.31) versus studies sponsored by industry (-0.73; 95% CI -1.00, -0.47) (p value<0.001). Statin efficacy did not differ by disclosure of financial conflict information, use of an optimal time window for outcome assessment, accounting for all animals, inclusion criteria, blinding, and randomization. Possible reasons for the differences between nonindustry- and industry-sponsored studies, such as selective reporting of outcomes, require further study. PMID:24465178

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

2014-01-01

2

Pasteurization of bone for tumour eradication prior to reimplantation – An in vitro & pre-clinical efficacy study  

PubMed Central

Background & objectives: In current era of limb-salvage therapy, pasteurization of bone sarcomas is receiving growing attention as a potential extracorporeal treatment and cost-effective alternative to allografts and radiation before surgical reimplantation. Detailed in vitro and in vivo pre-clinical study to evaluate efficacy of pasteurization to eradicate malignant cells has not been reported yet. The present study was carried out to assess the efficacy of pasteurization to kill tumour cells both in vitro and in vivo. Methods: Surgically resected specimens of osteosarcomas (n=4) were cut into equal halves and one section was pasteurized by heating at 60°C to 65°C for 40 min. Paired samples before and after pasteurization were studied in vitro for DNA ploidy, evaluation of histological change and elimination of mitotic activity. These tissues were transplanted in immune-deficient NOD-SCID mice to evaluate effect on tumour-generating ability, presence of human nuclei, osteopontin and cytokine/chemokines released in tumour-transplanted mice. Results: Non-pasteurized tumour samples had viable tumour cells which exhibited significant growth in culture, increased proliferative ability and clonogenic potential while respective pasteurized tumour tissues did not grow in culture and did not exhibit clonogenicity. Flow cytometry revealed that propidium iodide positive dead cells increased significantly (P< 0.01) post pasteurization. Seven of 12 non-pasteurized tumour transplanted mice demonstrated tumour-forming ability as against 0 of 12 in pasteurized tumour transplanted mice. Solid tumour xenografts exhibited strong expression of anti-human nuclei and osteopontin by immunohistochemistry as well as secretary human interluekin-6 (IL-6) while pasteurized mice failed to express these markers. Interpretation & conclusions: This study has provided a basis to establish pasteurization as being efficacious in ensuring tumour eradication from resected bone tumour specimens. Pasteurized tumour bearing bone can thus safely be used to reconstruct large defects after tumour resection. PMID:24927346

Kode, Jyoti; Taur, Prasad; Gulia, Ashish; Jambhekar, Nirmala; Agarwal, Manish; Puri, Ajay

2014-01-01

3

Chronic Electrical Stimulation with a Suprachoroidal Retinal Prosthesis: A Preclinical Safety and Efficacy Study  

PubMed Central

Purpose To assess the safety and efficacy of chronic electrical stimulation of the retina with a suprachoroidal visual prosthesis. Methods Seven normally-sighted feline subjects were implanted for 96–143 days with a suprachoroidal electrode array and six were chronically stimulated for 70–105 days at levels that activated the visual cortex. Charge balanced, biphasic, current pulses were delivered to platinum electrodes in a monopolar stimulation mode. Retinal integrity/function and the mechanical stability of the implant were assessed monthly using electroretinography (ERG), optical coherence tomography (OCT) and fundus photography. Electrode impedances were measured weekly and electrically-evoked visual cortex potentials (eEVCPs) were measured monthly to verify that chronic stimuli were suprathreshold. At the end of the chronic stimulation period, thresholds were confirmed with multi-unit recordings from the visual cortex. Randomized, blinded histological assessments were performed by two pathologists to compare the stimulated and non-stimulated retina and adjacent tissue. Results All subjects tolerated the surgical and stimulation procedure with no evidence of discomfort or unexpected adverse outcomes. After an initial post-operative settling period, electrode arrays were mechanically stable. Mean electrode impedances were stable between 11–15 k? during the implantation period. Visually-evoked ERGs & OCT were normal, and mean eEVCP thresholds did not substantially differ over time. In 81 of 84 electrode-adjacent tissue samples examined, there were no discernible histopathological differences between stimulated and unstimulated tissue. In the remaining three tissue samples there were minor focal fibroblastic and acute inflammatory responses. Conclusions Chronic suprathreshold electrical stimulation of the retina using a suprachoroidal electrode array evoked a minimal tissue response and no adverse clinical or histological findings. Moreover, thresholds and electrode impedance remained stable for stimulation durations of up to 15 weeks. This study has demonstrated the safety and efficacy of suprachoroidal stimulation with charge balanced stimulus currents. PMID:24853376

Nayagam, David A. X.; Williams, Richard A.; Allen, Penelope J.; Shivdasani, Mohit N.; Luu, Chi D.; Salinas-LaRosa, Cesar M.; Finch, Sue; Ayton, Lauren N.; Saunders, Alexia L.; McPhedran, Michelle; McGowan, Ceara; Villalobos, Joel; Fallon, James B.; Wise, Andrew K.; Yeoh, Jonathan; Xu, Jin; Feng, Helen; Millard, Rodney; McWade, Melanie; Thien, Patrick C.; Williams, Chris E.; Shepherd, Robert K.

2014-01-01

4

Preclinical efficacy spectrum and pharmacokinetics of ixabepilone  

Microsoft Academic Search

Purpose  Ixabepilone, a semisynthetic analog of natural epothilone B, was developed for use in cancer treatment. This study extends\\u000a previous findings regarding the efficacy of ixabepilone and its low susceptibility to tumor resistance mechanisms and describes\\u000a the pharmacokinetics of this new antineoplastic agent.\\u000a \\u000a \\u000a \\u000a Methods  The cytotoxicity of ixabepilone was assessed in vitro in breast, lung, and colon tumor cell lines and in

Francis Y. F. Lee; Richard Smykla; Kathy Johnston; Krista Menard; Kelly McGlinchey; Russell W. Peterson; Amy Wiebesiek; Gregory Vite; Craig R. Fairchild; Robert Kramer

2009-01-01

5

An Independent Study of the Preclinical Efficacy of C2-8 in the R6/2 Transgenic Mouse Model of Huntington's Disease  

PubMed Central

Background C2-8 is a small molecule inhibitor of polyglutamine aggregation and can reduce photoreceptor neurodegeneration in a Drosophila model of Huntington's disease (HD). Further preclinical studies have shown that oral administration of C2-8 in R6/2 HD transgenic mice can penetrate into the brain, reduce mHTT-exon1 aggregation, improve motor performance and diminish striatal neuron atrophy. Objective In this independent preclinical study, we aimed to evaluate the pharmacokinetic properties and therapeutic efficacy of C2-8 intraperitoneal (IP) delivery in the R6/2 HD mouse. Methods R6/2 mice were IP injected with low dose C2-8 (10 mg/kg), high dose C2-8 (20 mg/kg), or vehicle twice daily from 3 weeks to 3 months old. Longitudinal behavioral tests (accelerating Rotarod and wire-hang) were performed to evaluate the motor deficits, and neuropathology was measured by unbiased stereology. Results We confirmed that the compound has good blood-brain-barrier penetration after acute or sub-chronic intraperitoneal delivery. Chronic treatment with C2-8 in R6/2 mice results in a significant reduction of nuclear mHTT aggregate volume in the brains, replicating a key finding of C2-8 as a polyglutamine aggregation inhibitor in vivo. However, by comparing HD mice with C2-8 treatment to those with vehicle treatment, we were unable to demonstrate significant amelioration of motor deficits using Rotarod and wire-hang tests. Moreover, we did not observe improvement in the striatal neurodegenerative pathology, as measured by brain weight, striatal volume, and striatal neuron volume in the C2-8 treated R6/2 mice. Conclusions Our study supports the practice of independent preclinical studies for novel molecules in HD therapeutic development and suggests that the use of alternative delivery strategies and full-length HD mouse models are likely needed to further assess whether the aggregate-inhibiting properties of C2-8 can be consistently translated into a preclinical benefit in HD mice. PMID:25062731

Wang, Nan; Lu, Xiao-Hong; Sandoval, Susana V.; Yang, X. William

2014-01-01

6

Efficacy of multiple exposure with low level He-Ne laser dose on acute wound healing: a pre-clinical study  

NASA Astrophysics Data System (ADS)

Investigations on the use of Low Level Laser Therapy (LLLT) for wound healing especially with the red laser light have demonstrated its pro-healing potential on a variety of pre-clinical and surgical wounds. However, until now, in LLLT the effect of multiple exposure of low dose laser irradiation on acute wound healing on well-designed pre-clinical model is not much explored. The present study aimed to investigate the effect of multiple exposure of low dose Helium Neon laser on healing progression of full thickness excision wounds in Swiss albino mice. Further, the efficacy of the multiple exposure of low dose laser irradiation was compared with the single exposure of optimum dose. Full thickness excision wounds (circular) of 15 mm diameter were created, and subsequently illuminated with the multiple exposures (1, 2, 3, 4 and 5 exposure/ week until healing) of He-Ne (632.8 nm, 4.02 mWcm-2) laser at 0.5 Jcm-2 along with single exposure of optimum laser dose (2 J/cm-2) and un-illuminated controls. Classical biophysical parameters such as contraction kinetics, area under the curve and the mean healing time were documented as the assessment parameters to examine the efficacy of multiple exposures with low level laser dose. Experimental findings substantiated that either single or multiple exposures of 0.5 J/cm2 failed to produce any detectable alterations on wound contraction, area under the curve and mean healing time compared to single exposure of optimum dose (2 Jcm-2) and un-illuminated controls. Single exposure of optimum, laser dose was found to be ideal for acute wound healing.

Prabhu, Vijendra; Rao, Bola Sadashiva S.; Mahato, Krishna Kishore

2014-02-01

7

Preclinical pharmacokinetics: an approach towards safer and efficacious drugs.  

PubMed

Lack of efficacy and toxicity are considered to be major reasons for drug failures and pharmacokinetics governs them to a large extent. Compound with favorable pharmacokinetics is more likely to be efficacious and safe. Therefore, the preclinical pharmacokinetic evaluation should be comprehensive enough to ensure that compounds do not fail in the clinic. Preclinical ADME screening facilitates early elimination of weak candidates and directs the entire focus of the drug development program towards fewer potential lead candidates. Hence, it is mandatory that the pre-clinical candidates are subjected to as many possible reality checks. Reliance on in-vitro tests should be minimized because they do not represent the real physiological environment but rather slow down the pace of a drug discovery program. Compounds can be straight away subjected to in-vivo high throughput screens such as cassette dosing, cassette analysis or rapid rat screen etc. Candidates with the desired in-vivo pharmacokinetic profile may be further profiled in-vitro, using assays such as metabolic stability, reaction phenotyping, CYP-450 inhibition and induction, plasma protein binding etc. in human microsomes, human recombinant CYP-450 enzymes and human plasma. This also provides an early indication of whether the compound which worked in animals would work in human as well. In-vitro metabolic stability profile is a qualitative as well as quantitative comparison of metabolism of a compound in human and animal models. It helps in identifying the right model for toxicity studies. Extensive metabolism is generally considered a liability as it limits the systemic exposure and shortens the half-life of a compound. Several strategies such as reduction of lipophilicity, modification and / or blocking of metabolically soft spots and use of enzyme inhibitors; have been developed to combat metabolism. In spite of several concerns, the fact that active metabolites of several marketed drugs have been developed as drugs with better efficacy, safety and pharmacokinetics profile; cannot be denied. Therefore, instead of considering metabolic instability a liability it can be exploited as a tool for discovering better drugs. It is equally important to identify the metabolic pathways of the drug candidates by conducting in-vitro CYP450 reaction phenotyping assays. The identification of drug metabolizing enzymes involved in the major metabolic pathways of a compound helps in predicting the probable drug-drug interactions in human. Compounds with more than one metabolic pathway have less likelihood of clinically significant drug interactions. In-vitro CYP450 inhibition and induction screens are used to evaluate the potential of compound towards drug - drug interactions and the most prone candidates may either be discarded or taken ahead with a caution. It is known that only unbound drug is pharmacologically active and therefore the assessment of bound fraction by the estimation of plasma protein binding of a compound is another important parameter to be explored in-vitro. In addition to the process of 'weeding out' weak candidates early in the drug discovery process, it is equally important to identify the probable causes of poor ADME exhibited by some compounds as this information is useful to medicinal chemists for improving upon backbones that exhibit un favorable pharmacokinetic profile. Toxicity study is the foundation of an INDA (Investigational new drug application) and therefore, the final selection of a compound can be performed only after proper toxicological evaluation in animal models. Toxicokinetics forms an integral part of toxicity study and is used to assess the exposure of candidates in toxicity models and correlate the drug levels in blood and various tissues with the toxicological findings. Although in-vivo screening of compounds in animal models and in-vitro assays in human recombinant CYP-450 enzymes help in drug candidate selection, both approaches have their own limitations. There is no certainty that the selected candidates will exhibit the desired

Singh, Sonu Sundd

2006-02-01

8

Preclinical Studies to Predict Efficacy of Vascular Changes Induced by Combretastatin A-4 Disodium Phosphate in Patients  

SciTech Connect

Purpose: To determine how combretastatin A-4 disodium phosphate (CA4DP) dose-dependent changes in radiation response of a C3H mouse mammary carcinoma relate to measurements of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters and how those mouse DCE-MRI results compare with published clinical DCE-MRI data. Methods and Materials: C3H mammary carcinomas grown in female CDF{sub 1} mice were treated when at 200 mm{sup 3} in size. Groups of mice were given graded radiation doses, either alone or followed 30 min later by an intraperitoneal injection of CA4DP, administered at doses of 10-250 mg/kg. The radiation dose producing local tumor control in 50% of treated animals at 90 days (TCD{sub 50}) was calculated for each CA4DP dose. DCE-MRI was performed before and 3 h after CA4DP administration, and parameters describing vascularity and interstitial volume were estimated. Results: TCD{sub 50} showed a dose-dependent decrease reaching significance at 25 mg/kg. At greater doses of 50 and 100 mg/kg, the TCD{sub 50} increased slightly and was not significantly different from that of controls. TCD{sub 50} significantly decreased again at 250 mg/kg. The drug dose-response curves for all post-treatment vascular DCE-MRI parameters showed a shape similar to that of the TCD{sub 50} curve. A similar dose dependency was seen with previously published clinical data. Conclusion: Our preclinical DCE-MRI data could predict the CA4DP enhancement of the tumor radiation response and suggest the clinical CA4DP doses necessary to improve the radiation response in patients.

Nielsen, Thomas [Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus (Denmark); Department of Neuroradiology, Aarhus University Hospital, Aarhus (Denmark)], E-mail: thomas@oncology.dk; Murata, Rumi [Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus (Denmark); Maxwell, Ross J. [University of Newcastle Upon Tyne, Northern Institute for Cancer Research, Newcastle Upon Tyne (United Kingdom); Stodkilde-Jorgensen, Hans [MR Research Centre, Aarhus University Hospital, Aarhus (Denmark); Ostergaard, Leif [Department of Neuroradiology, Aarhus University Hospital, Aarhus (Denmark); Horsman, Michael R. [Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus (Denmark)

2008-03-01

9

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

PubMed Central

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

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

2013-01-01

10

A Preclinical Study of the Safety and Efficacy of Occlusin Trade-Mark-Sign 500 Artificial Embolization Device in Sheep  

SciTech Connect

Introduction: This study evaluated the safety, effectiveness, and biodegradation of a new embolic agent, Occlusin Trade-Mark-Sign 503 Artificial Embolization Device (OCL 503). The agent consists of biodegradable poly-lactic-co-glycolic acid microspheres (150-212 {mu}m) coated with type I bovine collagen and was compared with Embosphere{sup Registered-Sign} Microspheres (300-500 {mu}m) in this controlled study of uterine artery embolization (UAE) in sheep. Methods: Unilateral UAE was performed in 32 adult ewes randomly assigned. Vessels were embolized to effective stasis. The cohort was divided into four groups, which were sacrificed at 1, 3, 6, and 12 months. Results: Both agents were 100% effective in achieving stasis. At 6 months, all OCL 503-treated arteries were occluded, the microspheres degraded with time, and at 12 months all four animals examined demonstrated recanalization. OCL 503 was found in the untreated uterine artery in one animal with no other evidence of non target embolization. In the Embosphere-treated group, all vessels remained occluded and microspheres were detected in the contralateral uterine artery in 6 of 15 examined vessels and in 10 vaginal, 2 ovarian, and 1 vesical artery. No procedural-related complications were seen in either group. Conclusions: OCL 503 is as effective an embolic agent as Embosphere{sup Registered-Sign} Microspheres when embolizing ovine uterine arteries and resorbs with time, allowing recanalization of the treated arteries. No device-related issues or adverse events were observed.

Owen, Richard J., E-mail: drrichardowen@tbwifi.ca [University of Alberta, Radiology and Diagnostic Imaging, Walter C. Mackenzie Health Sciences Centre (Canada); Nation, Patrick N. [University of Alberta, Laboratory Medicine and Pathology, Walter C. Mackenzie Health Sciences Centre (Canada); Polakowski, Robert [BioLipids Inc (Canada); Biliske, Jennifer A. [University of Alberta, Biological Sciences, CW405, Biological Sciences Building (Canada); Tiege, Paul B. [University of Alberta, Lipid Products Research Alberta (LiPRA), 410 Agriculture/Forestry Centre (Canada); Griffith, Irwin J. [IMBiotechnologies Ltd (Canada)

2012-06-15

11

Efficacy of Pimobendan in the Prevention of Congestive Heart Failure or Sudden Death in Doberman Pinschers with Preclinical Dilated Cardiomyopathy (The PROTECT Study)  

PubMed Central

Background The benefit of pimobendan in delaying the progression of preclinical dilated cardiomyopathy (DCM) in Dobermans is not reported. Hypothesis That chronic oral administration of pimobendan to Dobermans with preclinical DCM will delay the onset of CHF or sudden death and improve survival. Animals Seventy-six client-owned Dobermans recruited at 10 centers in the UK and North America. Methods The trial was a randomized, blinded, placebo-controlled, parallel group multicenter study. Dogs were allocated in a 1:1 ratio to receive pimobendan (Vetmedin capsules) or visually identical placebo. The composite primary endpoint was prospectively defined as either onset of CHF or sudden death. Time to death from all causes was a secondary endpoint. Results The proportion of dogs reaching the primary endpoint was not significantly different between groups (P = .1). The median time to the primary endpoint (onset of CHF or sudden death) was significantly longer in the pimobendan (718 days, IQR 441–1152 days) versus the placebo group (441 days, IQR 151–641 days) (log-rank P = 0.0088). The median survival time was significantly longer in the pimobendan (623 days, IQR 491–1531 days) versus the placebo group (466 days, IQR 236–710 days) (log-rank P = .034). Conclusion and Clinical Importance The administration of pimobendan to Dobermans with preclinical DCM prolongs the time to the onset of clinical signs and extends survival. Treatment of dogs in the preclinical phase of this common cardiovascular disorder with pimobendan can lead to improved outcome. PMID:23078651

Summerfield, NJ; Boswood, A; O'Grady, MR; Gordon, SG; Dukes-McEwan, J; Oyama, MA; Smith, S; Patteson, M; French, AT; Culshaw, GJ; Braz-Ruivo, L; Estrada, A; O'Sullivan, ML; Loureiro, J; Willis, R; Watson, P

2012-01-01

12

Preclinical randomised safety, efficacy and physiologic study of the silicon dioxide inert-coated Axetis and bare metal stent: short-, mid- and long-term outcome.  

PubMed

Aims: To evaluate the short-, mid- and long-term safety, efficacy and vascular physiology of Axetis silicon dioxide (SiO2, abrading the micropores) inert-coated stent implantation in a randomised preclinical setting. Methods and results: Coronary arteries of domestic pigs were randomised to receive either Axetis or BMS (same design) stents with one-, three- and six-month follow-up (FUP), controlled by coronary angiography, optical coherence tomography (OCT), intravascular ultrasound (IVUS) and histology (n=32). The time-dependent vasomotor reaction of coronary arteries to stenting was measured using modified myography (n=12). Complete endothelialisation of the Axetis stent was confirmed by OCT, IVUS and histology at one-month FUP. Histopathology revealed continuous healing of the vessel wall with a gradual reduction of inflammation and fibrin score during the six-month FUP in both stent types. Significantly smaller neointimal area and %area stenosis were measured in Axetis stents compared with BMS at each FUP time point. Vascular reactivity measurements showed significantly better endothelium-dependent vasodilation of stented arteries with Axetis implantation. Conclusions: Implantation of the Axetis SiO2-coated stent resulted in a significantly better safety, efficacy and vessel physiology profile compared with BMS of the same design with a continuous decrease in vessel inflammation during the six-month FUP. PMID:24769439

Pavo, Noemi; Syeda, Bonni; Bernhart, Andreas; Szentirmai, Eszter; Hemetsberger, Rayyan; Samaha, Eslam; Plass, Christian; Zlabinger, Katrin; Pavo, Imre J; Petrasi, Zsolt; Petnehazy, Ors; Hoerstrup, Simon P; Maurer, Gerald; Gyöngyösi, Mariann

2014-04-29

13

Preclinical Studies of Amixicile, a Systemic Therapeutic Developed for Treatment of Clostridium difficile Infections That Also Shows Efficacy against Helicobacter pylori  

PubMed Central

Amixicile shows efficacy in the treatment of Clostridium difficile infections (CDI) in a mouse model, with no recurrence of CDI. Since amixicile selectively inhibits the action of a B vitamin (thiamine pyrophosphate) cofactor of pyruvate:ferredoxin oxidoreductase (PFOR), it may both escape mutation-based drug resistance and spare beneficial probiotic gut bacteria that do not express this enzyme. Amixicile is a water-soluble derivative of nitazoxanide (NTZ), an antiparasitic therapeutic that also shows efficacy against CDI in humans. In comparative studies, amixicile showed no toxicity to hepatocytes at 200 ?M (NTZ was toxic above 10 ?M); was not metabolized by human, dog, or rat liver microsomes; showed equivalence or superiority to NTZ in cytochrome P450 assays; and did not activate efflux pumps (breast cancer resistance protein, P glycoprotein). A maximum dose (300 mg/kg) of amixicile given by the oral or intraperitoneal route was well tolerated by mice and rats. Plasma exposure (rats) based on the area under the plasma concentration-time curve was 79.3 h · ?g/ml (30 mg/kg dose) to 328 h · ?g/ml (100 mg/kg dose), the maximum concentration of the drug in serum was 20 ?g/ml, the time to the maximum concentration of the drug in serum was 0.5 to 1 h, and the half-life was 5.6 h. Amixicile did not concentrate in mouse feces or adversely affect gut populations of Bacteroides species, Firmicutes, segmented filamentous bacteria, or Lactobacillus species. Systemic bioavailability was demonstrated through eradication of Helicobacter pylori in a mouse infection model. In summary, the efficacy of amixicile in treating CDI and other infections, together with low toxicity, an absence of mutation-based drug resistance, and excellent drug metabolism and pharmacokinetic metrics, suggests a potential for broad application in the treatment of infections caused by PFOR-expressing microbial pathogens in addition to CDI. PMID:24890599

Bruce, Alexandra M.; Olekhnovich, Igor; Warren, Cirle A.; Burgess, Stacey L.; Hontecillas, Raquel; Viladomiu, Monica; Bassaganya-Riera, Josep; Guerrant, Richard L.; Macdonald, Timothy L.

2014-01-01

14

USHERING IN THE STUDY AND TREATMENT OF PRECLINICAL ALZHEIMER DISEASE  

PubMed Central

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

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

2014-01-01

15

Efficacy and safety of mesenchymal stromal cells in preclinical models of acute lung injury: a systematic review protocol  

PubMed Central

Background Acute respiratory distress syndrome (ARDS) in humans is caused by an unchecked proinflammatory response that results in diffuse and severe lung injury, and it is associated with a mortality rate of 35 to 45%. Mesenchymal stromal cells (MSCs; ‘adult stem cells’) could represent a promising new therapy for this syndrome, since preclinical evidence suggests that MSCs may ameliorate lung injury. Prior to a human clinical trial, our aim is to conduct a systematic review to compare the efficacy and safety of MSC therapy versus controls in preclinical models of acute lung injury that mimic some aspects of the human ARDS. Methods/Design We will include comparative preclinical studies (randomized and non-randomized) of acute lung injury in which MSCs were administered and outcomes compared to animals given a vehicle control. The primary outcome will be death. Secondary outcomes will include the four key features of preclinical acute lung injury as defined by the American Thoracic Society consensus conference (histologic evidence of lung injury, altered alveolar capillary barrier, lung inflammatory response, and physiological dysfunction) and pathogen clearance for acute lung injury models that are caused by infection. Electronic searches of MEDLINE, Embase, BIOSIS Previews, and Web of Science will be constructed and reviewed by the Peer Review of Electronic Search Strategies (PRESS) process. Search results will be screened independently and in duplicate. Data from eligible studies will be extracted, pooled, and analyzed using random effects models. Risk of bias will be assessed using the Cochrane risk of bias tool, and individual study reporting will be assessed according to the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines. Discussion The results of this systematic review will comprehensively summarize the safety and efficacy of MSC therapy in preclinical models of acute lung injury. Our results will help translational scientists and clinical trialists to determine whether sufficient evidence exists to perform a human clinical trial. These results may also guide future acute lung injury preclinical and clinical research. PMID:24887266

2014-01-01

16

Antagonistic analogs of growth hormone-releasing hormone increase the efficacy of treatment of triple negative breast cancer in nude mice with doxorubicin; A preclinical study  

PubMed Central

Introduction This study evaluated the effects of an antagonistic analog of growth hormone-releasing hormone, MIA-602, on tumor growth, response to doxorubicin, expression of drug resistance genes, and efflux pump function in human triple negative breast cancers. Methods HCC1806 (doxorubicin-sensitive) and MX-1 (doxorubicin-resistant), cell lines were xenografted into nude mice and treated with MIA-602, doxorubicin, or their combination. Tumors were evaluated for changes in volume and the expression of the drug resistance genes MDR1 and NANOG. In-vitro cell culture assays were used to analyze the effect of MIA-602 on efflux pump function. Results Therapy with MIA-602 significantly reduced tumor growth and enhanced the efficacy of doxorubicin in both cell lines. Control HCC1806 tumors grew by 435%, while the volume of tumors treated with MIA-602 enlarged by 172.2% and with doxorubicin by 201.6%. Treatment with the combination of MIA-602 and doxorubicin resulted in an increase in volume of only 76.2%. Control MX-1 tumors grew by 907%, while tumors treated with MIA-602 enlarged by 434.8% and with doxorubicin by 815%. The combination of MIA-602 and doxorubicin reduced the increase in tumor volume to 256%. Treatment with MIA-602 lowered the level of growth hormone-releasing hormone and growth hormone-releasing hormone receptors and significantly reduced the expression of multidrug resistance (MDR1) gene and the drug resistance regulator NANOG. MIA-602 also suppressed efflux pump function in both cell lines. Conclusions We conclude that treatment of triple negative breast cancers with growth hormone-releasing hormone antagonists reduces tumor growth and potentiates the effects of cytotoxic therapy by nullifying drug resistance.

Perez, Roberto; Schally, Andrew V; Popovics, Petra; Cai, Renzhi; Sha, Wei; Rincon, Ricardo; Rick, Ferenc G.

2014-01-01

17

Efficacy of acetyldinaline for treatment of minimal residual disease (MRD): preclinical studies in the BNML rat model for human acute myelocytic leukemia.  

PubMed

The efficacy of acetyldinaline [4-acetylamino-N-(2'-aminophenyl)-benzamide] for eradication of minimal residual disease (MRD), which is left after bone marrow transplantation, and the risk of a bone marrow graft being jeopardized by this treatment was studied in the Brown Norway rat acute myelocytic leukemia model (BNML). To mimic the clinical situation, MRD induction treatment was given to rats showing clinical signs of leukemia and consisted of 80 mg/kg cyclophosphamide and 7.0 Gy X-rays total body irradiation resulting in a 6-8 log leukemic cell kill leaving 10-1000 leukemic cells in the animals. Treatment was completed with a syngeneic bone marrow transplant. A high dose level (HD) treatment of 23.7 mg acetyldinaline/kg per day and a low dose level (LD) treatment of 11.85 mg/kg per day, each given orally for five consecutive days, were compared. The increase in the survival time, the cure rate, and the toxic death rate were evaluated. One 5-day course of LD treatment, started at a time interval of 10, 17, or 24 days following MRD induction, resulted in 44%, 11% or 0% cures. With two 5-day courses of LD treatment, 89%, 22%, or 0% cures were achieved. With LD treatment, maximally an 8 log leukemic cell kill was obtained and no toxicity-related deaths were observed (only less than a 1 log kill of normal hemopoietic stem cells). In contrast, a single course of HD treatment resulted in 56% of the rats (10/18) dying from intestinal tract toxicity, while from the remaining eight rats at risk for relapse, three (37%) showed a very late relapse and five were cured (63%). It was evident that the leukemic cell load at the start of the acetyldinaline treatment determined the probability of relapse. An important finding was that acetyldinaline did not interfere with bone marrow regeneration. The highly curative potential of acetyldinaline treatment in the BNML model during the phase of MRD warrants the introduction of this compound in clinical phase I/II studies. PMID:8231248

el-Beltagi, H M; Martens, A C; Dahab, G M; Hagenbeek, A

1993-11-01

18

Drug-Eluting Stents in Preclinical Studies Updated Consensus Recommendations for Preclinical Evaluation  

PubMed Central

Coronary drug-eluting stents are commonplace in clinical practice with acceptable safety and efficacy. Preclinical evaluation of novel drug-eluting stent technologies has great importance for understanding safety and possibly efficacy of these technologies, and well-defined preclinical testing methods clearly benefit multiple communities within the developmental, testing, and clinical evaluation chain. An earlier consensus publication enjoyed widespread adoption but is in need of updating. This publication is an update, presenting an integrated view for testing drug-eluting technologies in preclinical models, including novel devices such as bioabsorbable coatings, totally bioabsorbable stents, bifurcation stents, and stent-free balloon-based drug delivery. This consensus document was produced by preclinical and translational scientists and investigators engaged in interventional technology community. The United States Food and Drug Administration (USFDA) recently issued a Draft Guidance for Industry Document for Drug-Eluting Stents. This expert consensus document is consistent with the Food and Drug Administration guidance. The dynamic nature of this field mandates future modifications and additions that will be added over time. PMID:20031669

Schwartz, Robert S.; Edelman, Elazer; Virmani, Renu; Carter, Andrew; Granada, Juan F.; Kaluza, Greg L.; Chronos, Nicolas A.F.; Robinson, Keith A.; Waksman, Ron; Weinberger, Judah; Wilson, Gregory J.; Wilensky, Robert L.

2010-01-01

19

Preclinical Studies of Novel Targeted Therapies  

PubMed Central

Summary The bone marrow (BM) milieu confers drug resistance in multiple myeloma (MM) cells to conventional therapies. Therefore novel biologically-based therapies are needed. Preclinical studies have identified and validated molecular targeted therapeutics in MM. In particular, recognition of the biologic significance of the BM microenvironment both in MM pathogenesis and as a potential target for novel therapeutics has already derived several promising approaches. Thalidomide, lenalidomide (Revlimid®) and bortezomib (Velcade®) are directed not only at MM cells, but also BM milieu, and have rapidly from the bench to the bedside and FDA approval to treat MM. PMID:17996589

Hideshima, Teru; Anderson, Kenneth C.

2008-01-01

20

[Efficacy studies].  

PubMed

Pravafenix(®) is a fixed-dose combination of 40mg of pravastatin and 160 mg of fenofibrate. The rationale behind the use of Pravafenix(®) is based on the increased residual cardiovascular risk observed in high risk patients with hypertriglyceridemia and/or low HDL cholesterol levels despite treatment with statins in monotherapy. In this article, we review the available evidence on the clinical efficacy of Pravafenix(®), which shows complementary benefits in the overall lipid profile of high risk patients with mixed dyslipidemia not controlled with 40-mg pravastatin or 20-mg simvastatin. PMID:25043542

Pedro-Botet, Juan; Flores-Le Roux, Juana A

2014-07-01

21

Superior preclinical efficacy of gemcitabine developed as chitosan nanoparticulate system.  

PubMed

Gemcitabine, an anticancer nucleoside analogue, undergoes rapid enzymatic degradation following intravenous injection. This necessitates the administration of a high order of doses to observe a required therapeutic response, while such high doses result in significant side effects. To improve the intravenous delivery of gemcitabine and simultaneously enhance its antitumor activity, we have investigated its incorporation into a drug nanoplatform based on the biodegradable polymer chitosan. Two gemcitabine loading methods have been investigated: (i) entrapment into the polymeric network (entrapment procedure): drug incorporation prior to the coacervation process that leads to the formation of gemcitabine-loaded chitosan (GemChit) nanoparticles; and (ii) surface deposition onto already formed chitosan nanoparticles after incubation in gemcitabine solution (adsorption procedure). The former method produced much higher gemcitabine loading values and a sustained release profile. The main factors determining the gemcitabine loading and release kinetic have also been analyzed. Following intravenous injection, the GemChit formulation displayed a significantly improved antitumor activity comparatively to free gemcitabine, which was further confirmed by histology and immunohistochemistry studies, suggesting the potential of this chitosan-based gemcitabine nanomedicine for the effective treatment of tumors. PMID:21117615

Arias, José L; Reddy, L Harivardhan; Couvreur, Patrick

2011-01-10

22

Preclinical Efficacy Testing for Stomach and Liver Cancers  

PubMed Central

Purpose Hollow fiber assays offer an early in vivo method of anticancer drug screening. The assays have been optimized for human cancers originating from the lung, breast, colon, ovary, and brain, but not from the stomach and liver. The current study focused on optimization of hollow fiber assays for gastric and hepatocellular carcinoma cell lines. Materials and Methods Gastric (SNU-16, SNU-484, SNU-668) and hepatocellular (HepG2, SK-Hep-1, Hep3B) carcinoma cell lines in hollow fibers were transplanted subcutaneously and intraperitoneally into mice, which were subsequently treated with a standard anticancer agent, paclitaxel. The hollow fiber activity of paclitaxel in each cell line was compared with the xenograft activity. Results Using optimized inoculation densities and schedules, treatment with paclitaxel was effective in gastric carcinoma cell lines, SNU-16 and SNU-484, but not in SNU-668. In the hollow fiber assays, paclitaxel was effective in hepatocellular carcinoma cell lines, HepG2 and SK-Hep-1, but not in Hep3B. Consistent with the results of the hollow fiber assay, SNU-16 and SNU-484, but not SNU-668, showed tumor regression, and HepG2 and SK-Hep-1, but not Hep3B, showed effective tumor responses following treatment with paclitaxel in xenograft models. When EW7197, a novel compound, and flavopiridol were tested in SNU-16 cells under optimized conditions, the hollow fiber activity showed good correlation with the xenograft activity of each compound. Conclusion Our protocols may be useful for screening candidate small molecules that may exhibit activity against stomach and liver cancers, both of which are common in Korea. PMID:24851111

Park, Jun Won; Baek, Nam Suk; Lee, Seok Cheol; Oh, Su Jin; Jang, Seok Hoon; Kim, In Hoo

2014-01-01

23

Sorafenib is efficacious and tolerated in combination with cytotoxic or cytostatic agents in preclinical models of human non-small cell lung carcinoma  

Microsoft Academic Search

Purpose: Sorafenib tosylate (sorafenib, BAY 43-9006, Nexavar®) is a multi-kinase inhibitor that targets tumor cell proliferation and angiogenesis. These studies evaluated the efficacy and tolerability of combinations of sorafenib plus agents used to treat non-small cell lung cancer (NSCLC) using preclinical models of that disease. Methods: Intravenous (iv) vinorelbine and interperitoneal (ip) cisplatin were administered intermittently (q4d × 3) in combination with

Christopher A. Carter; Charles Chen; Cheryl Brink; Patrick Vincent; Yulia Y. Maxuitenko; Karen S. Gilbert; William R. Waud; Xiaomei Zhang

2007-01-01

24

Evaluating the Suitability of Using Rat Models for Preclinical Efficacy and Side Effects with Inhaled Corticosteroids Nanosuspension Formulations  

NASA Astrophysics Data System (ADS)

Inhaled corticosteroids (ICS) are often prescribed as first-line therapy for patients with asthma Despite their efficacy and improved safety profile compared with oral corticosteroids, the potential for systemic side effects continues to cause concern. In order to reduce the potential for systemic side effects, the pharmaceutical industry has begun efforts to generate new drugs with pulmonary-targeted topical efficacy. One of the major challenges of this approach is to differentiate both efficacy and side effects (pulmonary vs. systemic) in a preclinical animal model. In this study, fluticasone and ciclesonide were used as tool compounds to explore the possibility of demonstrating both efficacy and side effects in a rat model using pulmonary delivery via intratracheal (IT) instillation with nanosuspension formulations. The inhibition of neutrophil infiltration into bronchoalveolar lavage fluid (BALF) and cytokine (TNF?) production were utilized to assess pulmonary efficacy, while adrenal and thymus involution as well as plasma corticosterone suppression was measured to assess systemic side effects. Based on neutrophil infiltration and cytokine production data, the ED50s for ciclesonide and fluticasone were calculated to be 0.1 and 0.03 mg, respectively. At the ED50, the average adrenal involution was 7.6 ± 5.3% for ciclesonide versus 16.6 ± 5.1% for fluticasone, while the average thymus involution was 41.0 ± 4.3% for ciclesonide versus 59.5 ± 5.8% for fluticasone. However, the differentiation became less significant when the dose was pushed to the EDmax (0.3 mg for ciclesonide, 0.1 mg for fluticasone). Overall, the efficacy and side effect profiles of the two compounds exhibited differentiation at low to mid doses (0.03-0.1 mg ciclesonide, 0.01-0.03 mg fluticasone), while this differentiation diminished at the maximum efficacious dose (0.3 mg ciclesonide, 0.1 mg fluticasone), likely due to overdosing in this model. We conclude that the rat LPS model using IT administration of nanosuspensions of ICS is a useful tool to demonstrate pulmonary-targeted efficacy and to differentiate the side effects. However, it is only suitable at sub-maximum efficacious levels.

Chiang, Po-Chang; Hu, Yiding; Blom, Jason D.; Thompson, David C.

2010-06-01

25

Analgesia in Amphibians: Preclinical Studies and Clinical Applications  

PubMed Central

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

Stevens, Craig W.

2010-01-01

26

PRECLINICAL STUDY Prediction of lymph node involvement in breast cancer  

E-print Network

PRECLINICAL STUDY Prediction of lymph node involvement in breast cancer from primary tumor tissue- ther lymph node involvement in breast cancer is influenced by gene or miRNA expression of the primary tissue from a group of 96 breast cancer patients balanced for lymph node involvement using Affymetrix

27

Sequential whole bladder photodynamic therapy treatments: A preclinical study  

Microsoft Academic Search

We postulated that sequential whole bladder photodynamic therapy (WBPDT) treatments with a low WBPDT dose would result in improved safety profile and good local tumor control. However, the drawback with such a proposal is the potential cumulative effect of sequential WBPDT treatments on bladder function. We designed this preclinical study to determine the safety of sequential WBPDT treatments. Six female

Uniyime O. Nseyo; Henry Kim; Joe DeBord; Karen Tate; Jean DeHaven

1997-01-01

28

Humanized cobra venom factor: structure, activity, and therapeutic efficacy in preclinical disease models.  

PubMed

The complement system is an integral component of both innate and adaptive immunity. However, complement is also a pathogenetic factor in many diseases. The development of agents for therapeutic complement inhibition is the topic of intense investigations by many investigators. We have developed a distinctly different therapeutic approach: complement depletion rather than inhibition. This approach is based on cobra venom factor (CVF), a C3 analog known to be able to safely deplete complement. This manuscript will briefly review the structure and activity of CVF, along with its similarities and differences to C3. Exploiting the knowledge of the structure/function relationship of CVF and C3, we created derivatives of human C3 which display the CVF-like activity of depleting complement, referred to as humanized CVF (hCVF). This review describes the structure and activity of hCVF, including the important property of not cleaving C5. The efficacy of hCVF for therapeutic complement depletion in nine preclinical models diseases with complement pathology is reviewed, including reperfusion injury, age-related macular degeneration (AMD), paroxysmal nocturnal hemoglobinuria (PNH), and immunogenicity of Factor VIII in hemophilia A. Complement depletion is characterized by the absence of toxicity, even after intra-arterial injection into the pulmonary artery of primates. No immunogenicity has been observed. PMID:25062833

Vogel, Carl-Wilhelm; Finnegan, Paul W; Fritzinger, David C

2014-10-01

29

Preclinical and Clinical Studies of Gamma Secretase Inhibitors with Docetaxel on Human Breast Tumors  

PubMed Central

Purpose Accumulating evidence supports the existence of breast cancer stem cells (BCSCs), which are characterized by their capacity to self-renew and divide indefinitely, and resistance to conventional therapies. The Notch pathway is important for stem cell renewal, and is a potential target for BCSC-directed therapy. Experimental Design Using human breast tumorgraft studies, we evaluated the impact of gamma secretase inhibitors (GSI) on the BCSC population and the efficacy of combining GSI with docetaxel treatment. The mouse experimental therapy paralleled a concurrent clinical trial in advanced breast cancer patients, designed to determine the maximally tolerated dose of the GSI, MK-0752, administered sequentially with docetaxel, and to evaluate BCSC markers in serial tumor biopsies. Results Treatment with GSI reduced BCSCs in MC1 and BMC-2147 tumorgrafts by inhibition of the Notch pathway. GSI enhanced the efficacy of docetaxel in preclinical studies. In the clinical trial, 30 patients with advanced breast cancer were treated with escalating doses of MK-0752 plus docetaxel. Clinically meaningful doses of both drugs were possible, with manageable toxicity and preliminary evidence of efficacy. A decrease in CD44+/CD24?, ALDH+, and MSFE were observed in tumors of patients undergoing serial biopsies. Conclusions These preclinical data demonstrate that pharmacological inhibition of the Notch pathway can reduce BCSCs in breast tumorgraft models. The clinical trial demonstrates feasibility of combination GSI and chemotherapy, and together these results encourage further study of Notch pathway inhibitors in combination with chemotherapy in breast cancer. PMID:23340294

Schott, Anne F.; Landis, Melissa D.; Dontu, Gabriela; Griffith, Kent A.; Layman, Rachel M.; Krop, Ian; Paskett, Lacey A; Wong, Helen; Dobrolecki, Lacey E.; Froehlich, Amber M.; Paranilam, Jaya; Hayes, Daniel F.; Wicha, Max S.; Chang, Jenny C.

2013-01-01

30

Eribulin—A review of preclinical and clinical studies  

PubMed Central

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

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

2013-01-01

31

Preclinical profile of a potent gamma-secretase inhibitor targeting notch signaling with in vivo efficacy and pharmacodynamic properties.  

PubMed

Notch signaling is an area of great interest in oncology. RO4929097 is a potent and selective inhibitor of gamma-secretase, producing inhibitory activity of Notch signaling in tumor cells. The RO4929097 IC50 in cell-free and cellular assays is in the low nanomolar range with >100-fold selectivity with respect to 75 other proteins of various types (receptors, ion channels, and enzymes). RO4929097 inhibits Notch processing in tumor cells as measured by the reduction of intracellular Notch expression by Western blot. This leads to reduced expression of the Notch transcriptional target gene Hes1. RO4929097 does not block tumor cell proliferation or induce apoptosis but instead produces a less transformed, flattened, slower-growing phenotype. RO4929097 is active following oral dosing. Antitumor activity was shown in 7 of 8 xenografts tested on an intermittent or daily schedule in the absence of body weight loss or Notch-related toxicities. Importantly, efficacy is maintained after dosing is terminated. Angiogenesis reverse transcription-PCR array data show reduced expression of several key angiogenic genes. In addition, comparative microarray analysis suggests tumor cell differentiation as an additional mode of action. These preclinical results support evaluation of RO4929097 in clinical studies using an intermittent dosing schedule. A multicenter phase I dose escalation study in oncology is under way. PMID:19773430

Luistro, Leopoldo; He, Wei; Smith, Melissa; Packman, Kathryn; Vilenchik, Maria; Carvajal, Daisy; Roberts, John; Cai, James; Berkofsky-Fessler, Windy; Hilton, Holly; Linn, Michael; Flohr, Alexander; Jakob-Røtne, Roland; Jacobsen, Helmut; Glenn, Kelli; Heimbrook, David; Boylan, John F

2009-10-01

32

Preclinical safety and efficacy models for pulmonary drug delivery of antimicrobials with focus on in vitro models.  

PubMed

New pharmaceutical formulations must be proven as safe and effective before entering clinical trials. Also in the context of pulmonary drug delivery, preclinical models allow testing of novel antimicrobials, reducing risks and costs during their development. Such models allow reducing the complexity of the human lung, but still need to reflect relevant (patho-) physiological features. This review focuses on preclinical pulmonary models, mainly in vitro models, to assess drug safety and efficacy of antimicrobials. Furthermore, approaches to investigate common infectious diseases of the respiratory tract, are emphasized. Pneumonia, tuberculosis and infections occurring due to cystic fibrosis are in focus of this review. We conclude that especially in vitro models offer the chance of an efficient and detailed analysis of new antimicrobials, but also draw attention to the advantages and limitations of such currently available models and critically discuss the necessary steps for their future development. PMID:25453270

Hittinger, Marius; Juntke, Jenny; Kletting, Stephanie; Schneider-Daum, Nicole; de Souza Carvalho, Cristiane; Lehr, Claus-Michael

2014-10-17

33

Preclinical efficacy of growth hormone-releasing hormone antagonists for androgen-dependent and castration-resistant human prostate cancer  

PubMed Central

Advanced hormone-sensitive prostate cancer responds to androgen-deprivation therapy (ADT); however, therapeutic options for recurrent castration-resistant disease are limited. Because growth hormone-releasing hormone (GHRH) and GHRH receptor (GHRH-R) are regulated in an autocrine fashion in prostate cancer, inhibition of GHRH-R represents a compelling approach to treatment. We investigated the effects of the latest series of improved, highly potent GHRH antagonists—MIA-602, MIA-606, and MIA-690—on the growth of androgen-dependent as well as castration-resistant prostate cancer (CRPC) cells in vitro and in vivo. GHRH-R and its splice variant, SV1, were present in 22Rv1, LNCaP, and VCaP human prostate cancer cell lines. Androgen-dependent LNCaP and VCaP cells expressed higher levels of GHRH-R protein compared with castration-resistant 22Rv1 cells; however, 22Rv1 expressed higher levels of SV1. In vitro, MIA-602 decreased cell proliferation of 22Rv1, LNCaP, and VCaP prostate cancer cell lines by 70%, 61%, and 20%, respectively (all P < 0.05), indicating direct effects of MIA-602. In vivo, MIA-602 was more effective than MIA-606 and MIA-690 and decreased 22Rv1 xenograft tumor volumes in mice by 63% after 3 wk (P < 0.05). No noticeable untoward effects or changes in body weight occurred. In vitro, the VCaP cell line was minimally inhibited by MIA-602, but in vivo, this line showed a substantial reduction in growth of xenografts in response to MIA-602, indicating both direct and systemic inhibitory effects. MIA-602 also further inhibited VCaP xenografts when combined with ADT. This study demonstrates the preclinical efficacy of the GHRH antagonist MIA-602 for treatment of both androgen-dependent and CRPC. PMID:24395797

Fahrenholtz, Cale D.; Rick, Ferenc G.; Garcia, Maria I.; Zarandi, Marta; Cai, Ren-Zhi; Block, Norman L.; Schally, Andrew V.; Burnstein, Kerry L.

2014-01-01

34

Comparative efficacy and safety of the novel oral anticoagulants dabigatran, rivaroxaban and apixaban in preclinical and clinical development.  

PubMed

Therapeutic oral anticoagulation is still commonly achieved by administration of warfarin or other vitamin K antagonists that are associated with an untoward pharmacokinetic / pharmacodynamic (PK/PD) profile leading to a high incidence of bleeding complications or therapeutic failure. Hence, there is an unmet medical need of novel easy-to-use oral anticoagulants with improved efficacy and safety. Recent developments include the identification of non-peptidic small-molecules that selectively inhibit certain serine proteases within the coagulation cascade. Of these, the thrombin inhibitor dabigatran and factor Xa inhibitor rivaroxaban have recently been licensed for thromboprophylaxis after orthopaedic surgery mainly in Europe. In addition, the factor Xa inhibitor apixaban is in late-stage clinical development. Each drug is prescribed at fixed doses without the need of anticoagulant monitoring. Phase III trials in orthopaedic patients essentially resulted in non-inferior efficacy of dabigatran and superior efficacy of rivaroxaban over enoxaparin without any marked differences of drug safety, while apixaban data is still controversial. However, alterations of rivaroxaban and apixaban pharmacokinetics upon interactions with inhibitors and inducers of CYP3A4 or P-glycoprotein may complicate the use of these compounds in daily practice, whereas dabigatran elimination largely depends on renal function. Hence, this review reports PK/PD, efficacy and safety data of dabigatran, rivaroxaban and apixaban throughout preclinical and clinical development. PMID:20135071

Ufer, Mike

2010-03-01

35

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

PubMed

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

Kwon, Youngjoo

2014-11-01

36

Resveratrol: A review of preclinical studies for human cancer prevention  

SciTech Connect

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.

Athar, Mohammad; Back, Jung Ho; Tang Xiuwei [Department of Dermatology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street VC15-204, New York, NY 10032 (United States); Kim, Kwang Ho [Department of Dermatology, Hallym University College of Medicine (Korea, Republic of); Kopelovich, Levy [Division of Cancer Prevention, National Cancer Institute, Bethesda, MD 20892 (United States); Bickers, David R. [Department of Dermatology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street VC15-204, New York, NY 10032 (United States); Kim, Arianna L. [Department of Dermatology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street VC15-204, New York, NY 10032 (United States)], E-mail: ak309@columbia.edu

2007-11-01

37

Preclinical and clinical studies of peptide receptor radionuclide therapy.  

PubMed

In the 1980s, the (111)In-labeled somatostatin analog OctreoScan (Covidien, Hazelwood, MO) was developed for imaging of somatostatin receptor subtype 2 (sst(2)) overexpressing tumors. On the basis of this success, peptide receptor radionuclide therapy (PRRT) was developed using similar somatostatin analogs with different therapeutic radionuclides. Clinical application of PRRT demonstrated impressive results on tumor response, overall survival, and quality of life in patients with gastroenteropancreatic neuroendocrine tumors. The peptides 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), Tyr(3)-octreotate (DOTATATE) and DOTA, Tyr(3)-octreotide (DOTATOC) (brand name Onalta), predominantly targeting sst(2), have been granted Orphan Drug status by the European Medicines Agency and the US Food and Drug Administration for application in PRRT. Besides somatostatin receptor-targeting peptides, multiple other radiopeptide analogs were developed targeting several other receptors overexpressed on various tumors. Some of these peptide analogs, including cholecystokinin, gastrin, gastrin-releasing peptide, arginine-glycine-aspartate (RGD)-peptides, and glucagon-like peptide 1 analogs appeared very promising in preclinical and clinical imaging and PRRT studies. Although the success of PRRT with radiolabeled somatostatin analogs has been established, there is still room for improvement. The therapeutic window of PRRT could be enlarged by the use of new and improved targeting compounds, of which new antagonists with excellent tumor to background ratios are very promising. Furthermore, locoregional administration, improved healthy tissue protection, and combination treatment can be applied to increase the effectiveness of PRRT. Combination treatment might include cocktails of different peptide analogs of different therapeutic radionuclides and of radiolabeled peptides with chemotherapeutic or radiosensitizing agents. This review summarizes results of PRRT and describes clinical and preclinical studies regarding PRRT optimizing strategies. PMID:20350630

Pool, Stefan E; Krenning, Eric P; Koning, Gerben A; van Eijck, Casper H J; Teunissen, Jaap J M; Kam, Boen; Valkema, Roelf; Kwekkeboom, Dik J; de Jong, Marion

2010-05-01

38

Preclinical safety and efficacy assessments of dendrimer-based (SPL7013) microbicide gel formulations in a nonhuman primate model.  

PubMed

Three gel formulations (1%, 3%, and 5% [wt/wt]) of SPL7013, a dendrimer known to have antiviral (anti-human immunodeficiency virus and anti-herpes simplex virus) activities, completed a range of preclinical tests in the pigtailed macaque models for vaginally and rectally applied topical microbicide safety assessments. The vaginal safety profile of the 3% SPL7013 gel formulation was equal to that of the 1% formulation but was superior to that of the 5% formulation. The 3% SPL7013 gel was further evaluated for rectal safety and for antichlamydial efficacy with cervical challenge with Chlamydia trachomatis. This first-generation dendrimer-based product was shown to be safe to the vaginal and rectal microenvironments with repeated daily use. However, a single intravaginal application of the 3% (wt/wt) SPL7013 gel did not provide protection from the acquisition of cervical chlamydial infection. PMID:16641437

Patton, D L; Cosgrove Sweeney, Y T; McCarthy, T D; Hillier, S L

2006-05-01

39

Progression of structural neuropathology in preclinical Huntington's disease: a tensor based morphometry study  

PubMed Central

Background and objectives: Regional cerebral atrophy occurs in carriers of the Huntington's disease (HD) gene mutation before clinical diagnosis is possible. The current inability to reliably measure progression of pathology in this preclinical phase impedes development of therapies to delay clinical onset. We hypothesised that longitudinal statistical imaging would detect progression of structural pathology in preclinical carriers of the HD gene mutation, in the absence of measurable clinical change. Methods: Thirty subjects (17 preclinical mutation positive, 13 mutation negative) underwent serial clinical and magnetic resonance imaging (MRI) assessments over an interval of 2 years. Statistically significant changes in regional grey and white matter volume on MRI were analysed using tensor based morphometry (TBM). This technique derives a voxel-wise estimation of regional tissue volume change from the deformation field required to warp a subject's early to late T1 images. Results: Over 2 years, there was progressive regional grey matter atrophy in mutation-positive relative to negative subjects, without significant clinical progression of disease. Significant grey matter volume loss was limited to bilateral putamen and globus pallidus externa (GPe), left caudate nucleus, and left ventral midbrain in the region of the substantia nigra. Conclusions: While these results are consistent with previous cross sectional pathologic and morphometric studies, significant progression of atrophy in HD before the onset of significant clinical decline is now demonstrable with longitudinal statistical imaging. Such measures could be used to assess the efficacy of potential disease modifying drugs in slowing the progression of pathology before confirmed clinical onset of HD. PMID:15834021

Kipps, C; Duggins, A; Mahant, N; Gomes, L; Ashburner, J; McCusker, E

2005-01-01

40

Preclinical therapeutic efficacy of a novel pharmacological inducer of apoptosis in malignant peripheral nerve sheath tumors  

PubMed Central

Neurofibromatosis Type 1 (NF1) is an autosomal disorder that affects neural crest-derived tissues, leading to a wide spectrum of clinical presentations. Patients commonly present with plexiform neurofibromas, benign but debilitating growths that can transform into malignant peripheral nerve sheath tumors (MPNSTs), a main cause of mortality. Currently, surgery is the primary course of treatment for MPNST, but with the limitation that these tumors are highly invasive. Radiation therapy is another treatment option, but is undesirable because it can induce additional mutations. MPNST patients may also receive doxorubicin as therapy, but this DNA-intercalating agent has relatively low tumor specificity and limited efficacy. In this study, we exploited a robust genetically-engineered mouse model of MPNST that recapitulates human NF1 associated MPNST to identify a novel small chemical compound that inhibits tumor cell growth. Compound 21 (Cpd21) inhibits growth of all available in vitro models of MPNST and human MPNST cell lines, while remaining non-toxic to normally-dividing Schwann cells or mouse embryonic fibroblasts. We show that this compound delays the cell cycle and leads to cellular apoptosis. Moreover, Cpd21 can reduce MPNST burden in a mouse allograft model, underscoring the compound’s potential as a novel chemotherapeutic agent. PMID:24285727

Chau, Vincent; Lim, S. Kyun; Mo, Wei; Liu, Chiachi; Patel, Amish J.; McKay, Renée M.; Wei, Shuguang; Posner, Bruce A.; De Brabander, Jef K.; Williams, Noelle S.; Parada, Luis F.; Le, Lu Q.

2014-01-01

41

Neurochemical responses to antidepressants in the prefrontal cortex of mice and their efficacy in preclinical models of anxiety-like and depression-like behavior: a comparative and correlational study  

Microsoft Academic Search

Rational  Marble burying and forced swimming behavior are widely used and sensitive tests for identifying clinically effective antidepressant\\u000a drugs, although the underlying neurobiology of these behaviors is not fully elucidated.\\u000a \\u000a \\u000a \\u000a Objectives  The objective of this study was to determine the relationship between the behavioral effects of antidepressant drugs and their\\u000a ability to modulate extracellular neurotransmitter levels in the prefrontal cortex.\\u000a \\u000a \\u000a \\u000a Materials and

Tomohiro Kobayashi; Etsuko Hayashi; Midori Shimamura; Mine Kinoshita; Niall P. Murphy

2008-01-01

42

Single agent efficacy of the VEGFR kinase inhibitor axitinib in preclinical models of glioblastoma.  

PubMed

Anti-angiogenic therapy is a promising therapeutic strategy for the highly vascular and malignant brain tumor, glioblastoma (GBM), although current clinical trials have failed to demonstrate an extension in overall survival. The small molecule tyrosine kinase inhibitor axitinib that targets vascular endothelial growth factor receptor, potently inhibits angiogenesis and has single-agent clinical activity in non-small cell lung, thyroid, and advanced renal cell cancer. Here we show that axitinib exerts direct cytotoxic activity against a number of patient-derived GBM stem cell (GSCs) and an endothelial cell line, and inhibits endothelial tube formation in vitro. Axitinib treatment of mice bearing hypervascular intracranial tumors generated from human U87 glioma cells, MGG4 GSCs and mouse 005 GSCs significantly extended survival that was associated with decreases in tumor-associated vascularity. We thus show for the first time the anti-angiogenic effect and survival prolongation provided by systemic single agent treatment with axitinib in preclinical orthotopic GBM models including clinically relevant GSC models. These results support further investigation of axitinib as an anti-angiogenic agent for GBM. PMID:25213669

Lu, Lei; Saha, Dipongkor; Martuza, Robert L; Rabkin, Samuel D; Wakimoto, Hiroaki

2015-01-01

43

A crowdsourcing model for creating preclinical medical education study tools.  

PubMed

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. PMID:23619061

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

2013-06-01

44

Preclinical safety studies on autologous cultured human skin fibroblast transplantation.  

PubMed

Recently, FDA approved the clinical use of autologous fibroblasts (LAVIV™) for the improvement of nasolabial fold wrinkles in adults. The use of autologous fibroblasts for the augmentation of dermal and subcutaneous defects represents a potentially exciting natural alternative to the use of other filler materials for its long-term corrective ability and absence of allergic adverse effects proved by clinical application. However, compared to the clinical evidence, preclinical studies are far from enough. In this study, human skin-derived fibroblasts were cultured and expanded for both in vitro and in vivo observations. In vitro, the subcultured fibroblasts were divided into two groups. One set of cells underwent cell cycle and karyotype analysis at passages 5 and 10. The second group of cells was cocultured in medium with different concentrations of human skin extract D for the measurement of collagen concentration and cell count. In vivo, the subcultured fibroblasts were injected into nude mice subcutaneously. Biopsies were taken for morphology observation and specific collagen staining at 1, 2, and 3 months after injection. The results in vitro showed no significant differences in cell cycle distribution between passages 5 and 10. Cell proliferation and secretion were inhibited as the concentration of extract D increased. In vivo, the fibroblasts were remarkably denser on the experimental side with no dysplastic cells. Mitotic cells were easily observed at the end of the first month but were rare at the end of the third month. Type III collagen was detected at the end of the first month, while collagen type I was positive at the end of the second month. The content of both collagens increased as time passed. The above results indicated that the use of the autologous fibroblasts was safe, providing a basic support for clinical use of fibroblasts. PMID:23211390

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

2014-01-01

45

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

PubMed Central

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

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

2012-01-01

46

Pharmacokinetics, Trypanosoma brucei gambiense Efficacy, and Time of Drug Action of DB829, a Preclinical Candidate for Treatment of Second-Stage Human African Trypanosomiasis  

PubMed Central

Human African trypanosomiasis (HAT, also called sleeping sickness), a neglected tropical disease endemic to sub-Saharan Africa, is caused by the parasites Trypanosoma brucei gambiense and T. brucei rhodesiense. Current drugs against this disease have significant limitations, including toxicity, increasing resistance, and/or a complicated parenteral treatment regimen. DB829 is a novel aza-diamidine that demonstrated excellent efficacy in mice infected with T. b. rhodesiense or T. b. brucei parasites. The current study examined the pharmacokinetics, in vitro and in vivo activity against T. b. gambiense, and time of drug action of DB829 in comparison to pentamidine. DB829 showed outstanding in vivo efficacy in mice infected with parasites of T. b. gambiense strains, despite having higher in vitro 50% inhibitory concentrations (IC50s) than against T. b. rhodesiense strain STIB900. A single dose of DB829 administered intraperitoneally (5 mg/kg of body weight) cured all mice infected with different T. b. gambiense strains. No cross-resistance was observed between DB829 and pentamidine in T. b. gambiense strains isolated from melarsoprol-refractory patients. Compared to pentamidine, DB829 showed a greater systemic exposure when administered intraperitoneally, partially contributing to its improved efficacy. Isothermal microcalorimetry and in vivo time-to-kill studies revealed that DB829 is a slower-acting trypanocidal compound than pentamidine. A single dose of DB829 (20 mg/kg) administered intraperitoneally clears parasites from mouse blood within 2 to 5 days. In summary, DB829 is a promising preclinical candidate for the treatment of first- and second-stage HAT caused by both Trypanosoma brucei subspecies. PMID:23959303

Wenzler, Tanja; Yang, Sihyung; Braissant, Olivier; Boykin, David W.; Brun, Reto

2013-01-01

47

Pharmacokinetics, Trypanosoma brucei gambiense efficacy, and time of drug action of DB829, a preclinical candidate for treatment of second-stage human African trypanosomiasis.  

PubMed

Human African trypanosomiasis (HAT, also called sleeping sickness), a neglected tropical disease endemic to sub-Saharan Africa, is caused by the parasites Trypanosoma brucei gambiense and T. brucei rhodesiense. Current drugs against this disease have significant limitations, including toxicity, increasing resistance, and/or a complicated parenteral treatment regimen. DB829 is a novel aza-diamidine that demonstrated excellent efficacy in mice infected with T. b. rhodesiense or T. b. brucei parasites. The current study examined the pharmacokinetics, in vitro and in vivo activity against T. b. gambiense, and time of drug action of DB829 in comparison to pentamidine. DB829 showed outstanding in vivo efficacy in mice infected with parasites of T. b. gambiense strains, despite having higher in vitro 50% inhibitory concentrations (IC50s) than against T. b. rhodesiense strain STIB900. A single dose of DB829 administered intraperitoneally (5 mg/kg of body weight) cured all mice infected with different T. b. gambiense strains. No cross-resistance was observed between DB829 and pentamidine in T. b. gambiense strains isolated from melarsoprol-refractory patients. Compared to pentamidine, DB829 showed a greater systemic exposure when administered intraperitoneally, partially contributing to its improved efficacy. Isothermal microcalorimetry and in vivo time-to-kill studies revealed that DB829 is a slower-acting trypanocidal compound than pentamidine. A single dose of DB829 (20 mg/kg) administered intraperitoneally clears parasites from mouse blood within 2 to 5 days. In summary, DB829 is a promising preclinical candidate for the treatment of first- and second-stage HAT caused by both Trypanosoma brucei subspecies. PMID:23959303

Wenzler, Tanja; Yang, Sihyung; Braissant, Olivier; Boykin, David W; Brun, Reto; Wang, Michael Zhuo

2013-11-01

48

Dabrafenib; Preclinical Characterization, Increased Efficacy when Combined with Trametinib, while BRAF/MEK Tool Combination Reduced Skin Lesions  

PubMed Central

Mitogen-Activated Protein Kinase (MAPK) pathway activation has been implicated in many types of human cancer. BRAF mutations that constitutively activate MAPK signalling and bypass the need for upstream stimuli occur with high prevalence in melanoma, colorectal carcinoma, ovarian cancer, papillary thyroid carcinoma, and cholangiocarcinoma. In this report we characterize the novel, potent, and selective BRAF inhibitor, dabrafenib (GSK2118436). Cellular inhibition of BRAFV600E kinase activity by dabrafenib resulted in decreased MEK and ERK phosphorylation and inhibition of cell proliferation through an initial G1 cell cycle arrest, followed by cell death. In a BRAFV600E-containing xenograft model of human melanoma, orally administered dabrafenib inhibited ERK activation, downregulated Ki67, and upregulated p27, leading to tumor growth inhibition. However, as reported for other BRAF inhibitors, dabrafenib also induced MAPK pathway activation in wild-type BRAF cells through CRAF (RAF1) signalling, potentially explaining the squamous cell carcinomas and keratoacanthomas arising in patients treated with BRAF inhibitors. In addressing this issue, we showed that concomitant administration of BRAF and MEK inhibitors abrogated paradoxical BRAF inhibitor-induced MAPK signalling in cells, reduced the occurrence of skin lesions in rats, and enhanced the inhibition of human tumor xenograft growth in mouse models. Taken together, our findings offer preclinical proof of concept for dabrafenib as a specific and highly efficacious BRAF inhibitor and provide evidence for its potential clinical benefits when used in combination with a MEK inhibitor. PMID:23844038

King, Alastair J.; Arnone, Marc R.; Bleam, Maureen R.; Moss, Katherine G.; Yang, Jingsong; Fedorowicz, Kelly E.; Smitheman, Kimberly N.; Erhardt, Joseph A.; Hughes-Earle, Angela; Kane-Carson, Laurie S.; Sinnamon, Robert H.; Qi, Hongwei; Rheault, Tara R.; Uehling, David E.; Laquerre, Sylvie G.

2013-01-01

49

Preclinical efficacy of the synthetic retinoid ST1926 for treating adult T-cell leukemia/lymphoma.  

PubMed

Adult T-cell leukemia/lymphoma (ATL) is an aggressive neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1). The HTLV-1 oncoprotein Tax plays an important role in ATL pathogenesis. ATL carries a poor prognosis due to chemotherapy resistance, stressing the need for alternative therapies. Here, we investigate the preclinical efficacy of the synthetic retinoid ST1926 in ATL and peripheral T-cell lymphomas. Clinically achievable concentrations of ST1926 induced a dramatic inhibition of cell proliferation in malignant T-cell lines and primary ATL cells with minimal effect on resting or activated normal lymphocytes. ST1926 induced apoptosis, DNA damage, and upregulation of p53 proteins in malignant T cells, whereas it caused an early downregulation of Tax proteins in HTLV-1-positive cells. In murine ATL, oral treatment with ST1926 prolonged survival and reduced leukemia cell infiltration, white blood cell counts, and spleen mass. In spleens of ST1926-treated animals, p53 and p21 proteins were upregulated, poly (ADP-ribose) polymerase was cleaved, and Tax transcripts were reduced. These results highlight the promising use of ST1926 as a targeted therapy for ATL. PMID:25035162

El Hajj, Hiba; Khalil, Bariaa; Ghandour, Botheina; Nasr, Rihab; Shahine, Sharif; Ghantous, Akram; Abdel-Samad, Rana; Sinjab, Ansam; Hasegawa, Hideki; Jabbour, Mark; Hall, William W; Zaatari, Ghazi; Dbaibo, Ghassan; Pisano, Claudio; Bazarbachi, Ali; Darwiche, Nadine

2014-09-25

50

Bridging the Gap between Preclinical and Clinical Microbicide Trials: Blind Evaluation of Candidate Gels in Murine Models of Efficacy and Safety  

Microsoft Academic Search

BackgroundDespite significant protection in preclinical studies, cellulose sulfate (CS) failed to protect women against HIV-1\\/2 and was associated with a trend toward increased HIV-1 acquisition in one of the clinical trials. These results highlight the need for preclinical tests more predictive of clinical outcomes. The objective of this study was to test coded vaginal gels, including CS, in murine models

Theodore J. Segarra; Esra Fakioglu; Natalia Cheshenko; Sarah S. Wilson; Pedro M. M. Mesquita; Gustavo F. Doncel; Betsy C. Herold

2011-01-01

51

Preclinical Development of an In Vivo BCG Challenge Model for Testing Candidate TB Vaccine Efficacy  

PubMed Central

There is an urgent need for an immunological correlate of protection against tuberculosis (TB) with which to evaluate candidate TB vaccines in clinical trials. Development of a human challenge model of Mycobacterium tuberculosis (M.tb) could facilitate the detection of such correlate(s). Here we propose a novel in vivo Bacille Calmette-Guérin (BCG) challenge model using BCG immunization as a surrogate for M.tb infection. Culture and quantitative PCR methods have been developed to quantify BCG in the skin, using the mouse ear as a surrogate for human skin. Candidate TB vaccines have been evaluated for their ability to protect against a BCG skin challenge, using this model, and the results indicate that protection against a BCG skin challenge is predictive of BCG vaccine efficacy against aerosol M.tb challenge. Translation of these findings to a human BCG challenge model could enable more rapid assessment and down selection of candidate TB vaccines and ultimately the identification of an immune correlate of protection. PMID:21629699

Minassian, Angela M.; Ronan, Edward O.; Poyntz, Hazel; Hill, Adrian V. S.; McShane, Helen

2011-01-01

52

Preclinical development of an in vivo BCG challenge model for testing candidate TB vaccine efficacy.  

PubMed

There is an urgent need for an immunological correlate of protection against tuberculosis (TB) with which to evaluate candidate TB vaccines in clinical trials. Development of a human challenge model of Mycobacterium tuberculosis (M.tb) could facilitate the detection of such correlate(s). Here we propose a novel in vivo Bacille Calmette-Guérin (BCG) challenge model using BCG immunization as a surrogate for M.tb infection. Culture and quantitative PCR methods have been developed to quantify BCG in the skin, using the mouse ear as a surrogate for human skin. Candidate TB vaccines have been evaluated for their ability to protect against a BCG skin challenge, using this model, and the results indicate that protection against a BCG skin challenge is predictive of BCG vaccine efficacy against aerosol M.tb challenge. Translation of these findings to a human BCG challenge model could enable more rapid assessment and down selection of candidate TB vaccines and ultimately the identification of an immune correlate of protection. PMID:21629699

Minassian, Angela M; Ronan, Edward O; Poyntz, Hazel; Hill, Adrian V S; McShane, Helen

2011-01-01

53

Standardization of the Filovirus Plaque Assay for Use in Preclinical Studies  

PubMed Central

The filovirus plaque assay serves as the assay of choice to measure infectious virus in a cell culture, blood, or homogenized tissue sample. It has been in use for more than 30 years and is the generally accepted assay used to titrate virus in samples from animals treated with a potential antiviral therapeutic or vaccine. As these animal studies are required for the development of vaccines and therapeutics under the FDA Animal Rule, it is essential to have a standardized assay to compare their efficacies against the various filoviruses. Here, we present an evaluation of the conditions under which the filovirus plaque assay performs best for the Ebola virus Kikwit variant and the Angola variant of Marburg virus. The indicator cell type and source, inoculum volumes, length of incubation and general features of filovirus biology as visualized in the assay are addressed in terms of the impact on the sample viral titer calculations. These optimization studies have resulted in a plaque assay protocol which can be used for preclinical studies, and as a standardized protocol for use across institutions, to aid in data comparison. This protocol will be validated for use in GLP studies supporting advanced development of filovirus therapeutics and vaccines. PMID:23223188

Shurtleff, Amy C.; Biggins, Julia E.; Keeney, Ashley E.; Zumbrun, Elizabeth E.; Bloomfield, Holly A.; Kuehne, Ana; Audet, Jennifer L.; Alfson, Kendra J.; Griffiths, Anthony; Olinger, Gene G.; Bavari, Sina

2012-01-01

54

Natural substances and Alzheimer's disease: from preclinical studies to evidence based medicine.  

PubMed

Over the last 10 years, the potential therapeutic effects of nutraceuticals to prevent or delay Alzheimer's disease were proposed. Among dietary antioxidants curcumin, Ginkgo biloba and carnitines were extensively studied for their neuroprotective effects. The rationale for this alternative therapeutic approach was based on several preclinical studies which suggested the neuroprotective effects for curcumin, Ginkgo biloba and acetyl-l-carnitine due to either a free radical scavenging activity or the inhibition of pro-inflammatory pathways or the potentiation of the cell stress response. However, although these are interesting premises, clinical studies were not able to demonstrate significant beneficial effects of curcumin, Ginkgo biloba and acetyl-l-carnitine in improving cognitive functions in Alzheimer's disease patients. The aim of this review is to summarize the main pharmacologic features of curcumin, Ginkgo biloba and carnitines as well as to underlie the main outcomes reached by clinical studies designed to demonstrate the efficacy of these natural substances in Alzheimer's disease patients. This article is part of a Special Issue entitled: Antioxidants and Antioxidant Treatment in Disease. PMID:21939756

Mancuso, Cesare; Siciliano, Raffaella; Barone, Eugenio; Preziosi, Paolo

2012-05-01

55

MRI biomarkers for evaluation of treatment efficacy in preclinical diabetic retinopathy  

PubMed Central

Introduction: One sober consequence of the current epidemic of diabetes mellitus is that an increasing number of people world-wide will partially or completely lose their sight to diabetic retinopathy. Clinically, the sight-threatening complications of diabetes are diagnosed and treated based on visible retinal lesions (e.g., dot-blot hemorrhages or retinal neovascularization). However, such anatomical microvascular lesions are slow to respond with treatment. Thus, there remains an urgent need for imaging biomarkers that are abnormal before retinal lesions are visibly apparent and are responsive to treatment. Areas covered: Here, the development of new MRI methods, such as manganese-enhanced MRI, for evaluating early diabetes-evoked retinal pathophysiology, and its usefulness in guiding new treatments for diabetic retinopathy are reviewed. Expert opinion: In diabetic retinopathy, not all important diagnostic and prognostic needs are well served by optical methods. In the absence of gross anatomy changes, critical times when drug intervention is most likely to be successful at reducing vision loss are missed by most light-based methods and thus provide little help in guiding diagnosis and treatment. For example, before clinical symptoms, is there an optimal time to intervene with drug therapy? Is a drug reaching its target? How does one assess optimal drug dose, schedule, and routes? How well do current experimental models mimic the clinical condition? As discussed herein, MRI is as an analytical tool for addressing these unmet needs. Future clinical applications of MRI can be envisioned such as in clinical trials to assess drug treatment efficacy, or as an adjunct approach to refine or clarify a difficult clinical case. New MRI-generated hypotheses about the pathogenesis of diabetic retinopathy and its treatment are discussed. In the coming years, a substantial growth in the development and application of MRI is expected to address relevant question in both the basic sciences and in the clinic. PMID:23786440

Berkowitz, Bruce A; Bissig, David; Dutczak, Oliver; Corbett, Shannon; North, Rob; Roberts, Robin

2014-01-01

56

Investigating the Efficacy of Practical Skill Teaching: A Pilot-Study Comparing Three Educational Methods  

ERIC Educational Resources Information Center

Effective education of practical skills can alter clinician behaviour, positively influence patient outcomes, and reduce the risk of patient harm. This study compares the efficacy of two innovative practical skill teaching methods, against a traditional teaching method. Year three pre-clinical physiotherapy students consented to participate in a…

Maloney, Stephen; Storr, Michael; Paynter, Sophie; Morgan, Prue; Ilic, Dragan

2013-01-01

57

Pre-Clinical Assays Predict Pan-African Echis Viper Efficacy for a Species-Specific Antivenom  

PubMed Central

Background Snakebite is a significant cause of death and disability in subsistent farming populations of sub-Saharan Africa. Antivenom is the most effective treatment of envenoming and is manufactured from IgG of venom-immunised horses/sheep but, because of complex fiscal reasons, there is a paucity of antivenom in sub-Saharan Africa. To address the plight of thousands of snakebite victims in savannah Nigeria, the EchiTAb Study Group organised the production, testing and delivery of antivenoms designed to treat envenoming by the most medically-important snakes in the region. The Echis saw-scaled vipers have a wide African distribution and medical importance. In an effort to maximise the clinical utility of scarce antivenom resources in Africa, we aimed to ascertain, at the pre-clinical level, to what extent the E. ocellatus-specific EchiTAbG antivenom, which was designed specifically for Nigeria, neutralised the lethal activity of venom from two other African species, E. pyramidum leakeyi and E. coloratus. Methodology/Principal Findings Despite apparently quite distinctive venom protein profiles, we observed extensive cross-species similarity in the immuno-reactivity profiles of Echis species-specific antisera. Using WHO standard pre-clinical in vivo tests, we determined that the monospecific EchiTAbG antivenom was as effective at neutralising the venom-induced lethal effects of E. pyramidum leakeyi and E. coloratus as it was against E. ocellatus venom. Under the restricted conditions of this assay, the antivenom was ineffective against the lethal effects of venom from the non-African Echis species, E. carinatus sochureki. Conclusions/Significance Using WHO-recommended pre-clinical tests we have demonstrated that the new anti-E. ocellatus monospecific antivenom EchiTAbG, developed in response to the considerable snakebite-induced mortality and morbidity in Nigeria, neutralised the lethal effects of venoms from Echis species representing each taxonomic group of this genus in Africa. This suggests that this monospecific antivenom has potential to treat envenoming by most, perhaps all, African Echis species. PMID:21049058

Casewell, Nicholas R.; Cook, Darren A. N.; Wagstaff, Simon C.; Nasidi, Abdulsalami; Durfa, Nandul; Wüster, Wolfgang; Harrison, Robert A.

2010-01-01

58

Racer efficacy study  

Technology Transfer Automated Retrieval System (TEKTRAN)

Racer (ammonium nonanoate) is a non-selective contact herbicide that controls several weed species. Racer has been labeled by EPA in the past year for weed control in food crops and is close to receiving approval for use by organic producers. The objective of this study was to verify results from ...

59

A small-molecule therapeutic lead for Huntington's disease: Preclinical pharmacology and efficacy of C2-8 in the R6/2 transgenic mouse  

PubMed Central

Huntington's disease (HD) is a progressive neurodegenerative disease caused by a glutamine expansion within huntingtin protein. The exact pathological mechanisms determining disease onset and progression remain unclear. However, aggregates of insoluble mutant huntingtin (mhtt), a hallmark of HD, are readily detected within neurons in HD brain. Although aggregated polyglutamines may not be inherently toxic, they constitute a biomarker for mutant huntingtin useful for developing therapeutics. We previously reported that the small molecule, C2-8, inhibits polyglutamine aggregation in cell culture and brain slices and rescues degeneration of photoreceptors in a Drosophila model of HD. In this study, we assessed the therapeutic potential of C2-8 in the R6/2 mouse model of HD, which has been used to provide proof-of-concept data in considering whether to advance therapies to human HD. We show that, at nontoxic doses, C2-8 penetrates the blood–brain barrier and is present in brain at a high concentration. C2-8-treated mice showed improved motor performance and reduced neuronal atrophy and had smaller huntingtin aggregates. There have been no prior drug-like, non-toxic, brain-penetrable aggregation inhibitors to arise from cell-based high-throughput screens for reducing huntingtin aggregation that is efficacious in preclinical in vivo models. C2-8 provides an essential tool to help elucidate mechanisms of neurodegeneration in HD and a therapeutic lead for further optimization and development. PMID:17925440

Chopra, Vanita; Fox, Jonathan H.; Lieberman, Greg; Dorsey, Kathryn; Matson, Wayne; Waldmeier, Peter; Housman, David E.; Kazantsev, Aleksey; Young, Anne B.; Hersch, Steven

2007-01-01

60

Preclinical phase II study of ifosfamide in human tumour xenografts in vivo.  

PubMed

The in vivo effects of the oxazaphosphorine compound ifosfamide (IFO) on human tumour xenografts were assessed in thymus aplastic nude mice. The human origin of the tumours was confirmed by isoenzymatic and immunohistochemical methods. Tumour models were selected from a panel of 180 regularly growing, well-characterized xenografts. The maximum tolerated dose in tumour-bearing nude mice was determined to be 130 mg/kg per day given on days 1-3 and 15-17. After 21 days, lethality was 14% after i.p. and 6% after s.c. administration. A total of 43 human tumours were tested for antineoplastic activity, 15 of which (36%) showed regression: 4/5 breast cancer xenografts, 1/3 colon, 1/1 gastric, 2/7 non-small-cell lung cancers (NSCLC), 3/4 small-cell lung cancers (SCLC), 1/2 sarcomas and 3/3 testicular cancers. Two ovarian, two uterine and six renal cancer xenografts as well as three melanomas and five tumours of various histologies were resistant. In 30 human tumour xenografts, the antineoplastic efficacy of the two oxazaphosphorine derivatives cyclophosphamide and IFO was compared. The maximum tolerated dose of cyclophosphamide was 200 mg/kg per day given i.p. on days 1 and 15; it led to 17% lethality after 21 days. Cyclophosphamide induced tumour regression or remission in 10/30 xenografts (33%) and IFO in 13/30 (43%). In conclusion, the observed efficacy of IFO parallels the clinical situation. Breast, lung and testicular cancer and sarcomas proved to be responsive. The antitumoural activity of IFO shows similarities to that of cyclophosphamide; however, a higher response rate and lower toxicity were noted for the former. Preclinical phase II studies in nude mice seem to offer an effective way of identifying active drugs as well as sensitive tumour types for further clinical development. PMID:2347054

Berger, D P; Fiebig, H H; Winterhalter, B R; Wallbrecher, E; Henss, H

1990-01-01

61

Efficacy and mechanism of action of volasertib, a potent and selective inhibitor of polo-like kinases, in preclinical models of acute myeloid leukemia.  

PubMed

Polo-like kinase 1 (Plk1), a member of the Polo-like kinase family of serine/threonine kinases, is a key regulator of multiple steps in mitosis. Here we report on the pharmacological profile of volasertib, a potent and selective Plk inhibitor, in multiple preclinical models of acute myeloid leukemia (AML) including established cell lines, bone marrow samples from AML patients in short-term culture, and subcutaneous as well as disseminated in vivo models in immune-deficient mice. Our results indicate that volasertib is highly efficacious as a single agent and in combination with established and emerging AML drugs, including the antimetabolite cytarabine, hypomethylating agents (decitabine, azacitidine), and quizartinib, a signal transduction inhibitor targeting FLT3. Collectively, these preclinical data support the use of volasertib as a new therapeutic approach for the treatment of AML patients, and provide a foundation for combination approaches that may further improve and prolong clinical responses. PMID:25576074

Rudolph, Dorothea; Impagnatiello, Maria Antonietta; Blaukopf, Claudia; Sommer, Christoph; Gerlich, Daniel W; Roth, Mareike; Tontsch-Grunt, Ulrike; Wernitznig, Andreas; Savarese, Fabio; Hofmann, Marco H; Albrecht, Christoph; Geiselmann, Lena; Reschke, Markus; Garin-Chesa, Pilar; Zuber, Johannes; Moll, Jürgen; Adolf, Günther R; Kraut, Norbert

2015-03-01

62

Preclinical Evaluation of Efficacy and Safety of an Improved Lentiviral Vector for the Treatment of ?-Thalassemia and Sickle Cell Disease.  

PubMed

A previously published clinical trial demonstrated the benefit of autologous CD34(+) cells transduced with a selfinactivating lentiviral vector (HPV569) containing an engineered ?-globin gene (?(A-T87Q)-globin) in a subject with ? thalassemia major. This vector has been modified to increase transduction efficacy without compromising safety. In vitro analyses indicated that the changes resulted in both increased vector titers (3 to 4 fold) and increased transduction efficacy (2 to 3 fold). An in vivo study in which 58 ?-thalassemic mice were transplanted with vector- or mock-transduced syngenic bone marrow cells indicated sustained therapeutic efficacy. Secondary transplantations involving 108 recipients were performed to evaluate long-term safety. The six month study showed no hematological or biochemical toxicity. Integration site (IS) profile revealed an oligo/polyclonal hematopoietic reconstitution in the primary transplants and reduced clonality in secondary transplants. Tumor cells were detected in the secondary transplant mice in all treatment groups (including the control group), without statistical differences in the tumor incidence. Immunohistochemistry and quantitative PCR demonstrated that tumor cells were not derived from transduced donor cells. This comprehensive efficacy and safety data provided the basis for initiating two clinical trials with this second generation vector (BB305) in Europe and in the USA in patients with ?-thalassemia major and sickle cell disease. PMID:25429463

Negre, Olivier; Bartholomae, Cynthia; Beuzard, Yves; Cavazzana, Marina; Christiansen, Lauryn; Courne, Celine; Deichmann, Annette; Denaro, Maria; Dreuzy, Edouard de; Finer, Mitchell; Fronza, Raffaele; Gillet-Legrand, Beatrix; Joubert, Christophe; Kutner, Robert; Leboulch, Philippe; Maouche, Leila; Paulard, Anais; Pierciey, Francis J; Rothe, Michael; Ryu, Byoung; Schmidt, Manfred; Kalle, Christof von; Payen, Emmanuel; Veres, Gabor

2015-01-01

63

Preclinical efficacy of maternal embryonic leucine-zipper kinase (MELK) inhibition in acute myeloid leukemia.  

PubMed

Maternal embryonic leucine-zipper kinase (MELK), which was reported to be frequently up-regulated in various types of solid cancer, plays critical roles in formation and maintenance of cancer stem cells. However, little is known about the relevance of this kinase in hematologic malignancies. Here we report characterization of possible roles of MELK in acute myeloid leukemia (AML). MELK is expressed in AML cell lines and AML blasts with higher levels in less differentiated cells. MELK is frequently upregulated in AML with complex karyotypes and is associated with worse clinical outcome. MELK knockdown resulted in growth inhibition and apoptosis of leukemic cells. Hence, we investigated the potent anti-leukemia activity of OTS167, a small molecule MELK kinase inhibitor, in AML, and found that the compound induced cell differentiation and apoptosis as well as decreased migration of AML cells. MELK expression was positively correlated with the expression of FOXM1 as well as its downstream target genes. Furthermore, MELK inhibition resulted in downregulation of FOXM1 activity and the expression of its downstream targets. Taken together, and given that OTS167 is undergoing a phase I clinical trial in solid cancer, our study warrants clinical evaluation of this compound as a novel targeted therapy for AML patients. PMID:25365263

Alachkar, Houda; Mutonga, Martin B G; Metzeler, Klaus H; Fulton, Noreen; Malnassy, Gregory; Herold, Tobias; Spiekermann, Karsten; Bohlander, Stefan K; Hiddemann, Wolfgang; Matsuo, Yo; Stock, Wendy; Nakamura, Yusuke

2014-12-15

64

Preclinical efficacy of maternal embryonic leucine-zipper kinase (MELK) inhibition in acute myeloid leukemia  

PubMed Central

Maternal embryonic leucine-zipper kinase (MELK), which was reported to be frequently up-regulated in various types of solid cancer, plays critical roles in formation and maintenance of cancer stem cells. However, little is known about the relevance of this kinase in hematologic malignancies. Here we report characterization of possible roles of MELK in acute myeloid leukemia (AML). MELK is expressed in AML cell lines and AML blasts with higher levels in less differentiated cells. MELK is frequently upregulated in AML with complex karyotypes and is associated with worse clinical outcome. MELK knockdown resulted in growth inhibition and apoptosis of leukemic cells. Hence, we investigated the potent anti-leukemia activity of OTS167, a small molecule MELK kinase inhibitor, in AML, and found that the compound induced cell differentiation and apoptosis as well as decreased migration of AML cells. MELK expression was positively correlated with the expression of FOXM1 as well as its downstream target genes. Furthermore, MELK inhibition resulted in downregulation of FOXM1 activity and the expression of its downstream targets. Taken together, and given that OTS167 is undergoing a phase I clinical trial in solid cancer, our study warrants clinical evaluation of this compound as a novel targeted therapy for AML patients. PMID:25365263

Alachkar, Houda; Mutonga, Martin B.G.; Metzeler, Klaus H.; Fulton, Noreen; Malnassy, Gregory; Herold, Tobias; Spiekermann, Karsten; Bohlander, Stefan K.; Hiddemann, Wolfgang; Matsuo, Yo; Stock, Wendy; Nakamura, Yusuke

2014-01-01

65

Preclinical studies with synthetic peptides in systemic lupus erythematosus.  

PubMed

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease that causes multi-organ damage and significant morbidity and mortality. Various efforts have been made to modulate the imbalanced immune responses in this disease. The manipulation of the immune system through the use of soluble synthetic peptides serving as antigenic epitopes, in repeated doses, has been shown to induce immune tolerance and to reduce the clinical manifestations of the disease in murine models. Although clinical trials in humans with the anti-DNA Ig peptide hCDR1 have failed, recent results from a clinical trial with another peptide, p140, have shown promise. This review provides an overview on the preclinical and translational work with synthetic peptides in SLE. PMID:22201847

Amarilyo, Gil; Hahn, Bevra; La Cava, Antonio

2012-01-01

66

Pre-clinical and Clinical Safety Studies of CMX-2043: A Cytoprotective Lipoic Acid Analogue for Ischaemia–Reperfusion Injury  

PubMed Central

CMX-2043 is an ?-lipoic acid analogue targeted to reduction of cellular injury and organ damage due to ischaemia–reperfusion injury (IRI). It has been shown to be effective in a rat model of cardiac IRI. The studies here reported evaluate its safety and pharmacokinetic profile in preparation for human clinical studies in procedures associated with IRI. Safety and tolerability were tested in standard pre-clinical in vitro and animal models and in a Phase 1 human clinical trial. CMX-2043 did not bind to a wide range of receptors and specific targets at approximately 4 ?g/mL (10 ?M). It was not mutagenic by Ames assay, did not produce chromosome aberrations in Chinese hamster ovary (CHO) cells, and was negative for clastogenic potential. Toxicological studies in rats including both single and 14-day repeat intravenous doses and in dogs (single intravenous dose) with a 2-week recovery period were conducted. The NOAEL in rats and dogs was 30 and >10 mg/kg, respectively. No serious adverse events were reported in a placebo-controlled, sequential dose escalation Phase 1 clinical trial. The low toxicity in the pre-clinical studies and the absence of adverse events in the Phase 1 trial have supported investigation of CMX-2043 in a human efficacy trial. PMID:24751172

Kates, Steven A; Lader, Alan S; Casale, Ralph; Beeuwkes, Reinier

2014-01-01

67

Natural substances and Alzheimer's disease: From preclinical studies to evidence based medicine  

Microsoft Academic Search

Over the last 10years, the potential therapeutic effects of nutraceuticals to prevent or delay Alzheimer's disease were proposed. Among dietary antioxidants curcumin, Ginkgo biloba and carnitines were extensively studied for their neuroprotective effects. The rationale for this alternative therapeutic approach was based on several preclinical studies which suggested the neuroprotective effects for curcumin, Ginkgo biloba and acetyl-l-carnitine due to either

Cesare Mancuso; Raffaella Siciliano; Eugenio Barone; Paolo Preziosi

68

PRECLINICAL STUDY GRB7 is required for triple-negative breast cancer cell invasion  

E-print Network

PRECLINICAL STUDY GRB7 is required for triple-negative breast cancer cell invasion and survival Triple-negative breast cancer (TNBC) is a heterogeneous disease that is usually associated with poor. Keywords GRB7 Á Adapter proteins Á Triple-negative breast cancer Á Tumor cell invasion Á Receptor tyrosine

Kenny, Paraic

69

PRECLINICAL STUDY GRB7 is required for triple-negative breast cancer cell invasion  

E-print Network

PRECLINICAL STUDY GRB7 is required for triple-negative breast cancer cell invasion and survival+Business Media, LLC. 2011 Abstract Triple-negative breast cancer (TNBC) is a heterogeneous disease targets in this disease. Keywords GRB7 Á Adapter proteins Á Triple-negative breast cancer Á Tumor cell

Kenny, Paraic

70

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

ERIC Educational Resources Information Center

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.…

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

2014-01-01

71

Human ESC-Derived Dopamine Neurons Show Similar Preclinical Efficacy and Potency to Fetal Neurons when Grafted in a Rat Model of Parkinson’s Disease  

PubMed Central

Summary Considerable progress has been made in generating fully functional and transplantable dopamine neurons from human embryonic stem cells (hESCs). Before these cells can be used for cell replacement therapy in Parkinson’s disease (PD), it is important to verify their functional properties and efficacy in animal models. Here we provide a comprehensive preclinical assessment of hESC-derived midbrain dopamine neurons in a rat model of PD. We show long-term survival and functionality using clinically relevant MRI and PET imaging techniques and demonstrate efficacy in restoration of motor function with a potency comparable to that seen with human fetal dopamine neurons. Furthermore, we show that hESC-derived dopamine neurons can project sufficiently long distances for use in humans, fully regenerate midbrain-to-forebrain projections, and innervate correct target structures. This provides strong preclinical support for clinical translation of hESC-derived dopamine neurons using approaches similar to those established with fetal cells for the treatment of Parkinson’s disease. PMID:25517469

Grealish, Shane; Diguet, Elsa; Kirkeby, Agnete; Mattsson, Bengt; Heuer, Andreas; Bramoulle, Yann; Van Camp, Nadja; Perrier, Anselme L.; Hantraye, Philippe; Björklund, Anders; Parmar, Malin

2014-01-01

72

Human ESC-derived dopamine neurons show similar preclinical efficacy and potency to fetal neurons when grafted in a rat model of Parkinson's disease.  

PubMed

Considerable progress has been made in generating fully functional and transplantable dopamine neurons from human embryonic stem cells (hESCs). Before these cells can be used for cell replacement therapy in Parkinson's disease (PD), it is important to verify their functional properties and efficacy in animal models. Here we provide a comprehensive preclinical assessment of hESC-derived midbrain dopamine neurons in a rat model of PD. We show long-term survival and functionality using clinically relevant MRI and PET imaging techniques and demonstrate efficacy in restoration of motor function with a potency comparable to that seen with human fetal dopamine neurons. Furthermore, we show that hESC-derived dopamine neurons can project sufficiently long distances for use in humans, fully regenerate midbrain-to-forebrain projections, and innervate correct target structures. This provides strong preclinical support for clinical translation of hESC-derived dopamine neurons using approaches similar to those established with fetal cells for the treatment of Parkinson's disease. PMID:25517469

Grealish, Shane; Diguet, Elsa; Kirkeby, Agnete; Mattsson, Bengt; Heuer, Andreas; Bramoulle, Yann; Van Camp, Nadja; Perrier, Anselme L; Hantraye, Philippe; Björklund, Anders; Parmar, Malin

2014-11-01

73

Preclinical studies of N3-O-toluyl-fluorouracil-loaded lipid-based nanosuspensions in H22-bearing mice  

PubMed Central

Purpose N3-O-toluyl-fluorouracil (TFU) is a potential antitumor prodrug of 5-fluorouracil (5-FU), but its poor solubility has limited its use in clinic. This study aimed to improve the bioavailability of TFU by preparing TFU-loaded lipid-based nanosuspensions (TFU-LNS) and perform a preclinical evaluation. Methods TFU-LNS were prepared through high-pressure homogenization and were lyophilized afterwards. For in vitro test, the physicochemical properties and cytotoxicity against HegG2 cells were conducted. For in vivo evaluation, the pharmacokinetics, tissue distribution, and antitumor efficacy were investigated in H22-bearing Kunming mice. Results TFU showed different degradability in four media; in particular, nearly all of it converted to an equimolar amount of 5-FU in blank plasma of Wistar rats. The lyophilized TFU-LNS had a mean particle size of 180.03±3.11 nm and zeta potential of ?8.02±1.43 mV and showed no discernible changes after storage at 4°C for 3 months. In the in vivo antitumor study, the antitumor efficacy of TFU-LNS was consistent with that of 5-FU injection. Furthermore, TFU-LNS released a lower concentration of 5-FU in heart and kidney throughout the tissue distribution studies. Conclusion TFU-LNS exhibited convincing antitumor activity and easy scale-up opportunity, which suggests that TFU-LNS might be a promising drug delivery system for cancer therapy. PMID:24920908

Zhang, Juan; Li, Min; Liu, Zhihong; Wang, Lili; Liu, Yongjun; Zhang, Na

2014-01-01

74

Novel medication targets for the treatment of alcoholism: preclinical studies.  

PubMed

Alcoholism is a complex heterogeneous disease and a number of neurotransmitter and neuromodulator systems have been implicated in its manifestation. Consequently, it is unlikely that existing medications such as disulfiram (Antabuse®), naltrexone (ReVia®), acamprosate (Campral®)) can be efficacious in every individual. Thus, the development of novel therapeutic agents with greater selectivity and less unwanted effects for the treatment of this disease is one of the major objectives of alcohol research. This review summarizes the findings of five novel compounds with different neuronal targets for treating alcoholism. These compounds include sazetidine-A, which selectively desensitizes ?4?2 nicotinic receptors; carisbamate, a novel anti-epileptic agent; JNJ5234801, a novel anxiolytic agent; GS-455534, a highly selective inhibitor of mitochondrial aldehyde dehydrogenase; and JNJ-39220675, a selective histamine H3 antagonist. Inbred alcohol-preferring rats (iP), Fawn-Hooded (FH) rats, and P rats were used to evaluate the compounds. Naltrexone was used as a positive control in some experiments. All five compounds reduced alcohol consumption and preference. The mechanisms thought to underlie these effects suggest that, in addition to dopaminergic and opioidergic systems, other neuronal systems such as sodium channels (carisbamate), mitochondrial aldehyde dehydrogenase (GS-455534), 5-HT2 receptors (JNJ-5234801), histamine H3 receptors (JNJ-39220675), and ?4?2 nicotinic receptors (sazetidine-A) can be involved in alcohol drinking. Further work is necessary to confirm the exact mechanisms of action of each drug and to determine any viable targets for putative treatment of alcohol-use disorders. The article presents some promising patents on novel medication targets for the treatment of alcoholism. PMID:22574676

Rezvani, Amir H; Lawrence, Andrew J; Arolfo, Maria P; Levin, Edward D; Overstreet, David H

2012-08-01

75

Spinal Cord Tolerance in the Age of Spinal Radiosurgery: Lessons from Pre-clinical Studies  

PubMed Central

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 1970’s. 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 pre-clinical 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. Pre-clinical 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 is 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. PMID:21183290

Medin, Paul M.; Boike, Thomas P.

2010-01-01

76

Curaxin CBL0137 eradicates drug resistant cancer stem cells and potentiates efficacy of gemcitabine in preclinical models of pancreatic cancer  

PubMed Central

Pancreatic ductal adenocarcinoma (PDA) continues to be one of the deadliest cancers due to the absence of effective treatment. Curaxins are a class of small molecules with anti-cancer activity demonstrated in different models of cancer in mice. The lead curaxin compound, CBL0137, recently entered Phase I clinical trials. Curaxins modulate several important signaling pathways involved in the pathogenesis of PDA through inhibition of chromatin remodeling complex FACT. FACT is overexpressed in multiple types of tumor, with one of the highest rate of overexpression in PDA (59%). In this study, the efficacy of CBL0137 alone or in combination with current standard of care, gemcitabine, was tested against different models of PDA in vitro and in mouse models. It was found that CBL0137 alone is a potent inducer of apoptosis in pancreatic cancer cell lines and is toxic not only for proliferating bulk tumor cells, but also for pancreatic cancer stem cells. In mice, CBL0137 was effective against several PDA models, including orthotopic gemcitabine resistant PANC-1 model and patient derived xenografts, in which CBL0137 anti-tumor effect correlated with overexpression of FACT. Moreover, we observed synergy of CBL0137 with gemcitabine which may be explained by the ability of CBL0137 to inhibit several transcriptional programs induced by gemcitabine, including NF-kappaB response and expression of ribonucleotide reductase, one of the targets of gemcitabine in cells. This data suggest testing of CBL0137 efficacy in Phase II trial in PDA patients alone and in combination with gemcitabine. PMID:25402820

Burkhart, Catherine; Fleyshman, Daria; Kohrn, Rachael; Commane, Mairead; Garrigan, Jennifer; Kurbatov, Vadim; Toshkov, Ilya; Ramachandran, Rajesh; Martello, Laura; Gurova, Katerina V.

2014-01-01

77

Use of standardized SCID-hu Thy/Liv mouse model for preclinical efficacy testing of anti-human immunodeficiency virus type 1 compounds.  

PubMed Central

We have developed standardized procedures and practices for infection of SCID-hu Thy/Liv mice with human immunodeficiency virus type 1 for the prophylactic administration of antiviral compounds and for evaluation of the antiviral effect in vivo. Endpoint analyses included quantitation of viral load by intracellular p24 enzyme-linked immunosorbent assay, DNA PCR for the presence of proviral genomes, flow cytometry to measure the representation of CD4+ and CD8+ cells, and cocultivation for the isolation of virus. Efficacy tests in this model are demonstrated with the nucleoside analogs zidovudine and dideoxyinosine and with the nonnucleoside reverse transcriptase inhibitor nevirapine. This small-animal model should be particularly useful in the preclinical prioritization of lead compounds within a common chemical class, in the evaluation of alternative in vivo dosing regimens, and in the determination of appropriate combination therapy in vivo. PMID:8851606

Rabin, L; Hincenbergs, M; Moreno, M B; Warren, S; Linquist, V; Datema, R; Charpiot, B; Seifert, J; Kaneshima, H; McCune, J M

1996-01-01

78

A tumor-mimic model for evaluating the accuracy of HIFU preclinical studies: an in vivo study.  

PubMed

To date, the efficacy of ablative technologies such as HIFU for the treatment of liver tumors in humans has been studied in animal models without tumors or in small animals like rats and rabbits with established tumors. Because of the small size of these animals, the lesion produced by HIFU devices has to be small. Thus, the local and systemic effects of the treatment as encountered in humans cannot be studied. The purpose of this study was to use an in vivo tumor-mimic model to evaluate the accuracy of HIFU ablation in the liver in preclinical studies. Tumor mimics were created in in vivo porcine livers by injecting a 1-cc warm mixture of agarose, cellulose, glycerol and methylene blue, which formed 1-cm hyperechoic discrete lesions on sonograms. Three studies were carried out: (i) in vitro experiments were conducted to study the acoustical proprieties of the tumor mimics; (ii) in vivo experiments were conducted in 10 pigs to evaluate the tolerance of the tumor mimics when injected in the liver; (iii) ultrasound-guided HIFU ablation was performed in 10 pigs to demonstrate that it is possible to treat a predetermined zone accurately. It was shown that the acoustical properties of tumor mimics are visible in sonograms and do not modify the shape and dimensions of HIFU lesions. The local and biological tolerance of tumor mimics was excellent. In addition, it was demonstrated that the average difference between the predetermined location of the HIFU ablation and the actual coagulated area was 32%. Therefore, this tumor mimic can be used to teach HIFU ablation before starting clinical studies, especially if the ultrasound device is to be used manually, as the one presented in this study was. PMID:18002762

N'Djin, W A; Melodelima, D; Parmentier, H; Rivoire, M; Chapelon, J Y

2007-01-01

79

Therapeutic Applications of Incretin Mimetics for Metabolic Diseases: Preclinical Studies  

Technology Transfer Automated Retrieval System (TEKTRAN)

Exenatide (exendin-4) is an incretin mimetic peptide that shares several glucoregulatory actions with the endogenous incretin GLP-1. In addition to its actions on glucose control, exenatide produces effects to reduce food intake and body weight in all species studied. GLP-1 and exenatide have also b...

80

A Preclinical Study Combining the DNA Repair Inhibitor Dbait with Radiotherapy for the Treatment of Melanoma1  

PubMed Central

Melanomas are highly radioresistant tumors, mainly due to efficient DNA double-strand break (DSB) repair. Dbait (which stands for DNA strand break bait) molecules mimic DSBs and trap DNA repair proteins, thereby inhibiting repair of DNA damage induced by radiation therapy (RT). First, the cytotoxic efficacy of Dbait in combination with RT was evaluated in vitro in SK28 and 501mel human melanoma cell lines. Though the extent of RT-induced damage was not increased by Dbait, it persisted for longer revealing a repair defect. Dbait enhanced RT efficacy independently of RT doses. We further assayed the capacity of DT01 (clinical form of Dbait) to enhance efficacy of “palliative” RT (10 × 3 Gy) or “radical” RT (20 × 3 Gy), in an SK28 xenografted model. Inhibition of repair of RT-induced DSB by DT01 was revealed by the significant increase of micronuclei in tumors treated with combined treatment. Mice treated with DT01 and RT combination had significantly better tumor growth control and longer survival compared to RT alone with the “palliative” protocol [tumor growth delay (TGD) by 5.7-fold; median survival: 119 vs 67 days] or the “radical” protocol (TGD by 3.2-fold; median survival: 221 vs 109 days). Only animals that received the combined treatment showed complete responses. No additional toxicity was observed in any DT01-treated groups. This preclinical study provides encouraging results for a combination of a new DNA repair inhibitor, DT01, with RT, in the absence of toxicity. A first-in-human phase I study is currently under way in the palliative management of melanoma in-transit metastases (DRIIM trial). PMID:25379020

Biau, Julian; Devun, Flavien; Jdey, Wael; Kotula, Ewa; Quanz, Maria; Chautard, Emmanuel; Sayarath, Mano; Sun, Jian-Sheng; Verrelle, Pierre; Dutreix, Marie

2014-01-01

81

Technetium-99m galactosyl-neoglycoalbumin: preparation and preclinical studies  

SciTech Connect

Technetium-99m galactosyl-neoglycoalbumin ((Tc) NGA), a labeled analog ligand to the hepatocyte-specific receptor, hepatic binding protein (HBP), was prepared and tested for labeling yield, stability, biodistribution, toxicity, and dosimetry. The ligand was synthesized by the covalent coupling of a carbohydrate bifunctional reagent, 2-imino-2-ethyloxymethyl-1-thiogalactose, to human serum albumin. Testing in mice and rabbits revealed the product to be nontoxic and apyrogenic. Biodistribution studies in rabbits demonstrated the liver as the single focus of tracer uptake. Dosimetry was based on kinetic studies in three baboons. Absorbed doses to liver, small intestine, urinary bladder wall, and uterus were 0.089, 0.28, 0.56, and 0.88 rad/mCi, respectively. Total body, lens of the eye, red marrow, ovaries, and testes were less than 0.06 rad/mCi. High liver specificity imparted by receptor binding combined with high labeling yield, stability, acceptable dosimetry, and safety provide (Tc)NGA with the attributes required for routine clinical assessment of hepatocyte function.

Vera, D.R.; Stadalnik, R.C.; Krohn, K.A.

1985-10-01

82

Improving the Quality of NINDS-Supported Preclinical and Clinical Research through Rigorous Study Design and Transparent Reporting  

E-print Network

Improving the Quality of NINDS-Supported Preclinical and Clinical Research through Rigorous Study basic, translational, and clinical research. There is growing recognition that the quality community has developed principles to improve the design, implementation, review, and reporting of clinical

83

Luciferase fragment complementation imaging in preclinical cancer studies  

PubMed Central

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

Lake, Madryn C.; Aboagye, Eric O.

2014-01-01

84

Potential antianxiety activity of Fumaria indica: A preclinical study  

PubMed Central

Background: In the view of diverse CNS modulating properties of Fumaria indica, present study was planned to evaluate its putative anxiolytic activity in behavioural models of rats, followed by elucidation of mechanism of observed activity through biochemical estimations. Materials and Methods: Effects of seven daily 100, 200 and 400 mg/kg oral doses of a Fumaria indica extract (FI) was compared with those of an acute oral dose (5 mg/kg) of lorazepam in a battery of rat models consisting of open-field, elevated plus and zero maze, social interaction, and novelty induced feeding tests. Results: Dose dependant antianxiety effects of FI observed in all tests were qualitatively similar to those of the reference anxiolytic drug. Although FI treatments did not alter the concentrations of noradrenaline and serotonin in hippocampus and hypothalamus, concentrations of both these monoamines were dose dependently elevated in prefrontal cortex of FI treated animals. Flunitrazepam binding in brain frontal cortex was also elevated by the extract. Moreover, higher levels of brain expressions of the cytokines TNF-?, IL-1?, and IL-10 observed in animals with prior experience on elevated plus maze were almost completely reversed by the lowest dose of FI tested in the behavioral models. Conclusion: Taken together, these observations strongly suggest that FI is a functionally novel type of antianxiety agent, and that inhibition of cytokine expressions in the brain could be involved in its mode of action. PMID:23661988

Singh, Gireesh K.; Chauhan, Sudhir K.; Rai, Geeta; Chatterjee, Shyam S.; Kumar, Vikas

2013-01-01

85

Analgesic and hypnotic activities of Laghupanchamula: A preclinical study  

PubMed Central

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

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

2014-01-01

86

Teacher Efficacy: A Study of Construct Dimensions  

Microsoft Academic Search

This study examined the structure of a construct generally labeled teacher efficacy. A sample of 342 prospective and experienced teachers was administered an efficacy questionnaire adapted from the research of Gibson and Dembo (1984). Factor analytic procedures with varimax rotation were used to generate a two-factor solution that accounted for 32 % of the variance in scale scores. Contrary to

Thomas R. Guskey; Perry D. Passaro

1994-01-01

87

Development of novel combined anticalcification protocols including immunologic modification for prolonged durability of cardiac xenograft: preclinical study using large-animal long-term circulatory models.  

PubMed

Cardiac xenografts are conventionally cross-linked with glutaraldehyde (GA) to impart tissue stability, reduce antigenicity, and maintain tissue sterility. However, GA-fixed xenografts are prone to calcification after long-term implantation in humans, because of phospholipids, free aldehyde groups, and residual antigenicity. We evaluated preclinical safety and efficacy using large-animal long-term circulatory models for our novel combined anticalcification protocol including immunological modification, which had been proven effective in small animal experiments. Bovine/porcine xenografts were treated with decellularization, immunological modification with ?-galactosidase, GA fixation with organic solvent, and detoxification with glycine. Valve conduits made of these xenografts were transplanted into the pulmonary root of goats, and hemodynamic, radiological, immunohistopathological, and biochemical results were obtained for 12 months after implantation. Evaluation of echocardiography and cardiac catheterization demonstrated good hemodynamic status and function of the pulmonary xenograft valves. Durability of the xenografts was well preserved without calcification by specimen radiography and immunohistopathological examination. The calcium concentrations of the explanted xenografts were lower than the control xenografts. This preclinical study using large-animal long-term circulatory models demonstrated that our synergistic and simultaneous employment of multiple anticalcification therapies and novel tissue treatments, including immunological modifications, have promising safety and efficacy and should be examined further in future clinical studies. PMID:25303800

Lim, Hong-Gook; Jeong, Saeromi; Shin, Jun-Seop; Park, Chung-Gyu; Kim, Yong Jin

2015-01-01

88

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

PubMed

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

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

2014-01-01

89

Isolation and characterization of dendritic cells from common marmosets for preclinical cell therapy studies  

PubMed Central

Dendritic cells (DCs) have important functions as modulators of immune responses, and their ability to activate T cells is of great value in cancer immunotherapy. The isolation of DCs from the peripheral blood of rhesus and African green monkeys has been reported, but the immune system in the common marmoset remains poorly characterized, although it offers many potential advantages for preclinical studies. In the present study, we devised methods, based on techniques developed for mouse and human DC preparation, for isolating DCs from three major tissue sources in the common marmoset: bone marrow (BM), spleen and peripheral blood. Each set of separated cells was analysed using the cell surface DC-associated markers CD11c, CD80, CD83, CD86 and human leucocyte antigen (HLA)-DR, all of which are antibodies against human antigens, and the cells were further characterized both functionally and morphologically as antigen-presenting cells. BM proved to be an excellent cell source for the isolation of DCs intended for preclinical studies on cell therapy, for which large quantities of cells are required. In the BM-derived CD11c+ cell population, cells exhibiting the characteristic features of DCs were enriched, with the typical DC morphology and the abilities to undergo endocytosis, to secrete interleukin (IL)-12, and to stimulate Xenogenic T cells. Moreover, BM-derived DCs produced the neurotrophic factor NT-3, which is also found in murine splenic DCs. These results suggest that BM-derived DCs from the common marmoset may be useful for biological analysis and for preclinical studies on cell therapy for central nervous system diseases and cancer. PMID:18005037

Ohta, Shigeki; Ueda, Yoko; Yaguchi, Masae; Matsuzaki, Yumi; Nakamura, Masaya; Toyama, Yoshiaki; Tanioka, Yoshikuni; Tamaoki, Norikazu; Nomura, Tatsuji; Okano, Hideyuki; Kawakami, Yutaka; Toda, Masahiro

2008-01-01

90

Assessment of anti-inflammatory tumor treatment efficacy by longitudinal monitoring employing sonographic micro morphology in a preclinical mouse model  

Microsoft Academic Search

Background  With the development of increasingly sophisticated three-dimensional volumetric imaging methods, tumor volume can serve as\\u000a a robust and reproducible measurement of drug efficacy. Since the use of molecularly targeted agents in the clinic will almost\\u000a certainly involve combinations with other therapeutic modalities, the use of volumetric determination can help to identify\\u000a a dosing schedule of sequential combinations of cytostatic drugs

Sanjay Tiwari; Jan H Egberts; Olena Korniienko; Linda Köhler; Anna Trauzold; Claus C Glüer; Holger Kalthoff

2011-01-01

91

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

PubMed

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 or glutamic acid decarboxylase inhibition; a range of monoaminergic effects; and potential cannabinoid receptor modulation. Future research should focus on conducting human clinical trials on the plants reviewed with promising anxiolytic activity. PMID:23436255

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

2013-03-01

92

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

PubMed

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 < 0.001 for all) by Pearson's method. Using multiple linear regression analysis, anatomy scores could be predicted by pre-MD GPA, 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 < 0.001). Physiology scores could be estimated by pre-MD GPA, the percentage of expected reading, monthly earnings, and percentage of those who fell asleep during class and near exam time (R = 0.722, R(2) = 0.521, P < 0.001). Biochemistry scores could be calculated by pre-MD GPA, the percentage of expected reading, motivation to study medicine, student satisfaction with biochemistry, and exam performance expectations (R = 0.794, R(2) = 0.630, P < 0.001). In conclusion, pre-MD GPA and the percentage of expected reading are factors involved in producing good academic results in the first preclinical year. Anatomy and biochemistry, but not physiology, scores are influenced by satisfaction. PMID:24585466

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

2014-03-01

93

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

PubMed Central

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

Hartung, Thomas

2013-01-01

94

A comprehensive review of the preclinical efficacy profile of the ErbB family blocker afatinib in cancer.  

PubMed

Afatinib (also known as BIBW 2992) has recently been approved in several countries for the treatment of a distinct type of epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer. This manuscript comprehensively reviews the preclinical data on afatinib, an irreversible inhibitor of the tyrosine kinase activity of members of the epidermal growth factor receptor family (ErbB) including EGFR, HER2 and ErbB4. Afatinib covalently binds to cysteine 797 of the EGFR and the corresponding cysteines 805 and 803 in HER2 and ErbB4, respectively. Such covalent binding irreversibly inhibits the tyrosine kinase activity of these receptors, resulting in reduced auto- and transphosphorylation within the ErbB dimers and inhibition of important steps in the signal transduction of all ErbB receptor family members. Afatinib inhibits cellular growth and induces apoptosis in a wide range of cells representative for non-small cell lung cancer, breast cancer, pancreatic cancer, colorectal cancer, head and neck squamous cell cancer and several other cancer types exhibiting abnormalities of the ErbB network. This translates into tumour shrinkage in a variety of in vivo rodent models of such cancers. Afatinib retains inhibitory effects on signal transduction and in vitro and in vivo cancer cell growth in tumours resistant to reversible EGFR inhibitors, such as those exhibiting the T790M mutations. Several combination treatments have been explored to prevent and/or overcome development of resistance to afatinib, the most promising being those with EGFR- or HER2-targeted antibodies, other tyrosine kinase inhibitors or inhibitors of downstream signalling molecules. PMID:24643470

Modjtahedi, Helmout; Cho, Byoung Chul; Michel, Martin C; Solca, Flavio

2014-06-01

95

The Metabotropic Glutamate Receptor 4-Positive Allosteric Modulator VU0364770 Produces Efficacy Alone and in Combination with l-DOPA or an Adenosine 2A Antagonist in Preclinical Rodent Models of Parkinson's Disease  

PubMed Central

Parkinson's disease (PD) is a debilitating neurodegenerative disorder associated with severe motor impairments caused by the loss of dopaminergic innervation of the striatum. Previous studies have demonstrated that positive allosteric modulators (PAMs) of metabotropic glutamate receptor 4 (mGlu4), including N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxamide, can produce antiparkinsonian-like effects in preclinical models of PD. However, these early mGlu4 PAMs exhibited unsuitable physiochemical properties for systemic dosing, requiring intracerebroventricular administration and limiting their broader utility as in vivo tools to further understand the role of mGlu4 in the modulation of basal ganglia function relevant to PD. In the present study, we describe the pharmacologic characterization of a systemically active mGlu4 PAM, N-(3-chlorophenyl)picolinamide (VU0364770), in several rodent PD models. VU0364770 showed efficacy alone or when administered in combination with l-DOPA or an adenosine 2A (A2A) receptor antagonist currently in clinical development (preladenant). When administered alone, VU0364770 exhibited efficacy in reversing haloperidol-induced catalepsy, forelimb asymmetry-induced by unilateral 6-hydroxydopamine (6-OHDA) lesions of the median forebrain bundle, and attentional deficits induced by bilateral 6-OHDA nigrostriatal lesions in rats. In addition, VU0364770 enhanced the efficacy of preladenant to reverse haloperidol-induced catalepsy when given in combination. The effects of VU0364770 to reverse forelimb asymmetry were also potentiated when the compound was coadministered with an inactive dose of l-DOPA, suggesting that mGlu4 PAMs may provide l-DOPA-sparing activity. The present findings provide exciting support for the potential role of selective mGlu4 PAMs as a novel approach for the symptomatic treatment of PD and a possible augmentation strategy with either l-DOPA or A2A antagonists. PMID:22088953

Jones, Carrie K.; Bubser, Michael; Thompson, Analisa D.; Dickerson, Jonathan W.; Turle-Lorenzo, Nathalie; Amalric, Marianne; Blobaum, Anna L.; Bridges, Thomas M.; Morrison, Ryan D.; Jadhav, Satyawan; Engers, Darren W.; Italiano, Kimberly; Bode, Jacob; Daniels, J. Scott; Lindsley, Craig W.; Hopkins, Corey R.; Conn, P. Jeffrey

2012-01-01

96

Preclinical pharmacology, ocular tolerability and ocular hypotensive efficacy of a novel non-peptide bradykinin mimetic small molecule.  

PubMed

We sought to characterize the ocular pharmacology, tolerability and intraocular pressure (IOP)-lowering efficacy of FR-190997, a non-peptidic bradykinin (BK) B2-receptor agonist. FR-190997 possessed a relatively high receptor binding affinity (Ki = 27 nM) and a high in vitro potency (EC50 = 18.3 ± 4.4 nM) for inositol-1-phosphate generation via human cloned B2-receptors expressed in host cells with mimimal activity at B1-receptors. It also mobilized intracellular Ca2+ in isolated human trabecular meshwork (h-TM), ciliary muscle (h-CM), and in immortalized non-pigmented ciliary epithelial (h-iNPE) cells (EC50s = 167-384 nM; Emax = 32-86% of BK-induced response). HOE-140, a selective B2-receptor antagonist, potently blocked the latter effects of FR-190997 (e.g., IC50 = 7.3 ± 0.6 nM in h-CM cells). FR-190997 also stimulated the release of prostaglandins (PGs) from h-TM and h-CM cells (EC50s = 60-84 nM; Emax = 29-44% relative to max. BK-induced effects). FR-190997 (0.3-300 ?g t.o.) did not activate cat corneal polymodal nociceptors and did not cause ocular discomfort in Dutch-Belted rabbits, but it was not well tolerated in New Zealand albino rabbits and Hartley guinea pigs. A single topical ocular (t.o.) dose of 1% FR-190997 in Dutch-Belted rabbits and mixed breed cats did not lower IOP. However, FR-190997 efficaciously lowered IOP of conscious ocular hypertensive cynomolgus monkey eyes (e.g., 34.5 ± 7.5% decrease; 6 h post-dose of 30 ?g t.o.; n = 8). Thus, FR-190997 is an unexampled efficacious ocular hypotensive B2-receptor non-peptide BK agonist that activates multiple signaling pathways to cause IOP reduction. PMID:25307520

Sharif, Najam A; Li, Linya; Katoli, Parvaneh; Xu, Shouxi; Veltman, James; Li, Byron; Scott, Daniel; Wax, Martin; Gallar, Juana; Acosta, Carmen; Belmonte, Carlos

2014-11-01

97

Preclinical efficacy of sepantronium bromide (YM155) in multiple myeloma is conferred by down regulation of Mcl-1  

PubMed Central

The inhibitor-of-apoptosis family member survivin has been reported to inhibit apoptosis and regulate mitosis and cytokinesis. In multiple myeloma, survivin has been described to be involved in downstream sequelae of various therapeutic agents. We assessed 1093 samples from previously untreated patients, including two independent cohorts of 392 and 701 patients, respectively. Survivin expression was associated with cell proliferation, adverse prognostic markers, and inferior event-free and overall survival, supporting the evaluation of survivin as a therapeutic target in myeloma. The small molecule suppressant of survivin - YM155 - is in clinical development for the treatment of solid tumors. YM155 potently inhibited proliferation and induced apoptosis in primary myeloma cells and cell lines. Gene expression and protein profiling revealed the critical roles of IL6/STAT3-signaling and the unfolded protein response in the efficacy of YM155. Both pathways converged to down regulate anti-apoptotic Mcl-1 in myeloma cells. Conversely, growth inhibition and apoptotic cell death by YM155 was rescued by ectopic expression of Mcl-1 but not survivin, identifying Mcl-1 as the pivotal downstream target of YM155 in multiple myeloma. Mcl-1 expression was likewise associated with adverse prognostic markers, and inferior survival. Our results strongly support the clinical evaluation of YM155 in patients with multiple myeloma. PMID:25296978

Seckinger, Anja; Weiz, Ludmila; Meißner, Tobias; Rème, Thiery; Breitkreutz, Iris; Podar, Klaus; Ho, Anthony D.; Goldschmidt, Hartmut; Krämer, Alwin; Klein, Bernard; Raab, Marc S.

2014-01-01

98

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

PubMed Central

The use of systematic review and meta-analysis of preclinical studies has become more common, including those of studies describing the modeling of cerebrovascular diseases. Empirical evidence suggests that too many preclinical experiments lack methodological rigor, and this leads to inflated treatment effects. The aim of this review is to describe the concepts of systematic review and meta-analysis and consider how these tools may be used to provide empirical evidence to spur the field to improve the rigor of the conduct and reporting of preclinical research akin to their use in improving the conduct and reporting of randomized controlled trials in clinical research. As with other research domains, systematic reviews are subject to bias. Therefore, we have also suggested guidance for their conduct, reporting, and critical appraisal. PMID:24549183

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

2014-01-01

99

Genomic biomarkers for cardiotoxicity in rats as a sensitive tool in preclinical studies.  

PubMed

The development of safer drugs is a high priority for pharmaceutical companies. Among the various toxicities caused by drugs, cardiotoxicity is an important issue because of its lethality. In addition, cardiovascular toxicity leads to the attrition of many drug candidates in both preclinical and clinical phases. Although histopathological and blood chemistry examinations are the current gold standards for detecting cardiotoxicity in preclinical studies, the large number of withdrawals from clinical studies owing to safety problems indicate that a more sensitive tool is required. We recently identified 32 genes that were candidate genomic biomarkers for cardiotoxicity in rats. Based on their functions, the present study focused on 8 of these 32 genes (Spp1, Fhl1, Timp1, Serpine1, Bcat1, Lmcd1, Rnd1 and Tgfb2). Diagnostic accuracy for the genes was determined by a receiver-operating characteristic (ROC) analysis using more cardiotoxic and non-cardiotoxic compounds. In addition, an optimized support vector machine (SVM) model that was composed of Spp1 and Timp1 was newly constructed. This new multi-gene model exhibited a much higher diagnostic accuracy than that observed for plasma cardiac troponin I (cTnI), which is one of the most useful plasma biomarkers for cardiotoxicity detection. Furthermore, we determined that this multi-gene model could predict potential cardiotoxicity in rats in the absence of any cardiac histopathological lesions or elevations of plasma cTnI. Overall, this multi-gene model exhibited advantages over classic tools commonly used for cardiotoxicity evaluations in rats. Our current results suggest that application of the model could potentially lead to the production of safer drugs. PMID:23558518

Nishimura, Yoko; Morikawa, Yuji; Kondo, Chiaki; Tonomura, Yutaka; Fukushima, Ryou; Torii, Mikinori; Uehara, Takeki

2013-10-01

100

Fabry Disease: Preclinical Studies Demonstrate the Effectiveness of ?-Galactosidase A Replacement in Enzyme-Deficient Mice  

PubMed Central

Preclinical studies of enzyme-replacement therapy for Fabry disease (deficient ?-galactosidase A [?-Gal A] activity) were performed in ?-Gal A–deficient mice. The pharmacokinetics and biodistributions were determined for four recombinant human ?-Gal A glycoforms, which differed in sialic acid and mannose-6-phosphate content. The plasma half-lives of the glycoforms were ?2–5 min, with the more sialylated glycoforms circulating longer. After intravenous doses of 1 or 10 mg/kg body weight were administered, each glycoform was primarily recovered in the liver, with detectable activity in other tissues but not in the brain. Normal or greater activity levels were reconstituted in various tissues after repeated doses (10 mg/kg every other day for eight doses) of the highly sialylated AGA-1 glycoform; 4 d later, enzyme activity was retained in the liver and spleen at levels that were, respectively, 30% and 10% of that recovered 1 h postinjection. Importantly, the globotriaosylceramide (GL-3) substrate was depleted in various tissues and plasma in a dose-dependent manner. A single or repeated doses (every 48 h for eight doses) of AGA-1 at 0.3–10.0 mg/kg cleared hepatic GL-3, whereas higher doses were required for depletion of GL-3 in other tissues. After a single dose of 3 mg/kg, hepatic GL-3 was cleared for ?4 wk, whereas cardiac and splenic GL-3 reaccumulated at 3 wk to ?30% and ?10% of pretreatment levels, respectively. Ultrastructural studies demonstrated reduced GL-3 storage posttreatment. These preclinical animal studies demonstrate the dose-dependent clearance of tissue and plasma GL-3 by administered ?-Gal A, thereby providing the in vivo rationale—and the critical pharmacokinetic and pharmacodynamic data—for the design of enzyme-replacement trials in patients with Fabry disease. PMID:11115376

Ioannou, Yiannis A.; Zeidner, Ken M.; Gordon, Ronald E.; Desnick, Robert J.

2001-01-01

101

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

PubMed Central

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. PMID:24213461

Tanaka, Takuji

2012-01-01

102

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

PubMed Central

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

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

2011-01-01

103

The influence of storage parameters on measurement of survival motor neuron (SMN) protein levels: implications for pre-clinical studies and clinical trials for spinal muscular atrophy.  

PubMed

Spinal muscular atrophy (SMA) is caused by low levels of survival motor neuron (SMN) protein. A growing number of potential therapeutic strategies for SMA are entering pre-clinical and clinical testing, including gene therapy and antisense oligonucleotide-based approaches. For many such studies SMN protein levels are used as one major readout of treatment efficacy, often necessitating comparisons between samples obtained at different times and/or using different protocols. Whether differences in tissue sampling strategies or storage parameters have an influence on measurable SMN levels remains to be determined. We assessed murine SMN protein immunoreactivity over time and under differing tissue storage conditions. SMN protein levels, measured using sensitive quantitative fluorescent western blotting, declined rapidly over a period of several days following sample collection, especially when protein was extracted immediately and stored at -20°C. Storage of samples at lower temperatures (-80°C), and as intact tissue, led to significantly better preservation of SMN immunoreactivity. However, considerable deterioration in measurable SMN levels occurred, even under optimal storage conditions. These issues need to be taken into consideration when designing and interpreting pre-clinical and clinical SMA studies where SMN protein levels are being measured. PMID:25047670

Hunter, Gillian; Roche, Sarah L; Somers, Eilidh; Fuller, Heidi R; Gillingwater, Thomas H

2014-11-01

104

Creative Self-Efficacy: An Intervention Study  

ERIC Educational Resources Information Center

This study examined the effects of creativity training on creative self-efficacy. We developed a creativity course based on social cognitive theory. The course was conducted in two formats: a five-day course and a condensed one-day course. Samples consisted of students and municipality employees (five-day course), and special education teachers…

Mathisen, Gro Ellen; Bronnick, Kolbjorn S.

2009-01-01

105

Active and passive immunization strategies based on the SDPM1 peptide demonstrate pre-clinical efficacy in the APPswePSEN1dE9 mouse model for Alzheimer’s disease  

PubMed Central

Recent clinical and pre-clinical studies suggest that both active and passive immunization strategies targeting A? amyloid may have clinical benefit in Alzheimer’s disease. Here, we demonstrate that vaccination of APPswePSEN1dE9 mice with SDPM1, an engineered non-native A? amyloid-specific binding peptide, lowers brain A? amyloid plaque burden and brain A?1-40 and A?1-42 peptide levels, improves cognitive learning and memory in Morris Water maze tests and increases the expression of synaptic brain proteins. This was the case in young mice immunized prior to development of significant brain amyloid burden, and in older mice, where brain amyloid was already present. Active immunization was optimized using ALUM as an adjuvant to stimulate production of anti-SDPM1 and anti-A? amyloid antibodies. Intracerebral injection of P4D6, an SDPM1 peptide-mimotope antibody, also lowered brain amyloid plaque burden in APPswePSEN1dE9 mice. Additionally, P4D6 inhibited A? amyloid-mediated toxicity in cultured neuronal cells. The protein sequence of the variable domain within the P4D6 heavy chain was found to mimic a multimer of the SDPM1 peptide motif. These data demonstrate the efficacy of active and passive vaccine strategies to target specific A? amyloid oligomers using an engineered peptide-mimotope strategy. PMID:24021662

Camboni, Marybeth; Wang, Chiou-Miin; Miranda, Carlos; Yoon, Jung Hae; Xu, Rui; Zygmunt, Deborah; Kaspar, Brian K.; Martin, Paul T.

2013-01-01

106

Preclinical Study Design for Evaluation of Stem Cell-derived Cellular Therapy Products: A Pathologist's Perspective.  

PubMed

Despite-or perhaps because of-the rapid expansion of interest in stem cell-derived cellular therapy products, relatively few guidelines have been published to assist in the design of scientifically sound preclinical studies. The field is complex and wide ranging, and of necessity regulators tend to treat each project on a case by case basis. One of the core tenets remains the need to retain all tissues from the study, thereby allowing for further analysis of tissues should unexpected effects be seen in clinical studies; attempts to comply with this may result in an unmanageable financial burden. Judicious input from the pathologist at the earliest stages of study design may not only improve the scientific integrity of the study but also help to mitigate some of the cost. Careful animal selection, the development of robust cell markers, and justifiable triage of tissues based on phased tissue examination can all be discussed with the regulatory authorities at pre-pre-investigational new drug (IND) and pre-IND meetings to achieve optimal study design. PMID:25351922

Baker, Julia F M; Assaf, Basel T

2015-01-01

107

Handling of the cotton rat in studies for the pre-clinical evaluation of oncolytic viruses.  

PubMed

Oncolytic viruses are a novel anticancer therapy with the ability to target tumor cells, while leaving healthy cells intact. For this strategy to be successful, recent studies have shown that involvement of the host immune system is essential. Therefore, oncolytic virotherapy should be evaluated within the context of an immunocompetent model. Furthermore, the study of antitumor therapies in tolerized animal models may better recapitulate results seen in clinical trials. Cotton rats, commonly used to study respiratory viruses, are an attractive model to study oncolytic virotherapy as syngeneic models of mammary carcinoma and osteosarcoma are well established. However, there is a lack of published information on the proper handling procedure for these highly excitable rodents. The handling and capture approach outlined minimizes animal stress to facilitate experimentation. This technique hinges upon the ability of the researcher to keep calm during handling and perform procedures in a timely fashion. Finally, we describe how to prepare cotton rat mammary tumor cells for consistent subcutaneous tumor formation, and how to perform intratumoral and intraperitoneal injections. These methods can be applied to a wide range of studies furthering the development of the cotton rat as a relevant pre-clinical model to study antitumor therapy. PMID:25490047

Cuddington, Breanne; Verschoor, Meghan; Mossman, Karen

2014-01-01

108

Preclinical Efficacy of N-Substituted Benztropine Analogs as Antagonists of Methamphetamine Self-Administration in Rats  

PubMed Central

Atypical dopamine-uptake inhibitors have low abuse potential and may serve as leads for development of cocaine-abuse treatments. Among them, the benztropine (BZT) derivatives, N-butyl (JHW007), N-allyl (AHN2-005), and N-methyl (AHN1-055) analogs of 3?-[bis(4?-fluorophenyl)methoxy]-tropane dose-dependently decreased cocaine self-administration without effects on food-maintained responding. Our study examined selectivity by assessing their effects on self-administration of other drugs. As with cocaine, each BZT analog (1.0–10.0 mg/kg i.p.) dose-dependently decreased maximal self-administration of d-methamphetamine (0.01–0.32 mg/kg/infusion) but was inactive against heroin (1.0–32.0 µg/kg/infusion) and ketamine (0.032–1.0 mg/kg/infusion) self-administration. Further, standard dopamine indirect-agonists [WIN35,428 ((?)-3?-(4-fluorophenyl)-tropan-2-?-carboxylic acid methyl ester tartrate), d-amphetamine (0.1–1.0 mg/kg i.p., each)] dose-dependently left-shifted self-administration dose-effect curves for d-methamphetamine, heroin, and ketamine. Noncompetitive NMDA-glutamate receptor/channel antagonists [(+)-MK-801 (0.01–0.1 mg/kg i.p.), memantine (1.0–10.0 mg/kg i.p.)] also left-shifted dose-effect curves for d-methamphetamine and ketamine (but not heroin) self-administration. The µ-agonists [dl-methadone and morphine (1.0–10.0 mg/kg i.p., each)] dose-dependently decreased maximal self-administration of µ-agonists (heroin, remifentanil) but not d-methamphetamine or ketamine self-administration. The µ-agonist-induced decreases were similar to the effects of BZT analogs on stimulant self-administration and effects of food prefeeding on responding maintained by food reinforcement. Radioligand-binding and behavioral studies suggested that inhibition of dopamine transporters and ? receptors were critical for blocking stimulant self-administration by BZT-analogs. Thus, the present results suggest that the effects of BZT analogs on stimulant self-administration are similar to effects of µ-agonists on µ-agonist self-administration and food prefeeding on food-reinforced responding, which implicates behavioral mechanisms for these effects and further supports development of atypical dopamine uptake inhibitors as medications for stimulant abuse. PMID:24194527

Hiranita, Takato; Kohut, Stephen J.; Soto, Paul L.; Tanda, Gianluigi; Kopajtic, Theresa A.

2014-01-01

109

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

PubMed Central

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

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

2014-01-01

110

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

NASA Astrophysics Data System (ADS)

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.

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

2011-02-01

111

Preclinical Studies with Umbilical Cord Mesenchymal Stromal Cells in Different Animal Models for Muscular Dystrophy  

PubMed Central

Umbilical cord mesenchymal stromal cells (MSC) have been widely investigated for cell-based therapy studies as an alternative source to bone marrow transplantation. Umbilical cord tissue is a rich source of MSCs with potential to derivate at least muscle, cartilage, fat, and bone cells in vitro. The possibility to replace the defective muscle cells using cell therapy is a promising approach for the treatment of progressive muscular dystrophies (PMDs), independently of the specific gene mutation. Therefore, preclinical studies in different models of muscular dystrophies are of utmost importance. The main objective of the present study is to evaluate if umbilical cord MSCs have the potential to reach and differentiate into muscle cells in vivo in two animal models of PMDs. In order to address this question we injected (1) human umbilical cord tissue (hUCT) MSCs into the caudal vein of SJL mice; (2) hUCT and canine umbilical cord vein (cUCV) MSCs intra-arterially in GRMD dogs. Our results here reported support the safety of the procedure and indicate that the injected cells could engraft in the host muscle in both animal models but could not differentiate into muscle cells. These observations may provide important information aiming future therapy for muscular dystrophies. PMID:21785565

Zucconi, Eder; Vieira, Natassia Moreira; Bueno, Carlos Roberto; Secco, Mariane; Jazedje, Tatiana; Costa Valadares, Marcos; Fussae Suzuki, Miriam; Bartolini, Paolo; Vainzof, Mariz; Zatz, Mayana

2011-01-01

112

A multistep validation process of biomarkers for preclinical drug development  

Microsoft Academic Search

Biomarkers that can be measured in preclinical models in a high-throughput, reproducible manner offer the potential to increase the speed and efficacy of drug development. Development of therapeutic agents for many conditions is hampered by the limited number of validated preclinical biomarkers available to gauge pharmacoefficacy and disease progression, but the validation process for preclinical biomarkers has received limited attention.

W M Freeman; G V Bixler; R M Brucklacher; C-M Lin; K M Patel; H D VanGuilder; K F LaNoue; S R Kimball; A J Barber; D A Antonetti; T W Gardner; S K Bronson

2010-01-01

113

Scaling Pharmacodynamics from In Vitro and Preclinical Animal Studies to Humans  

PubMed Central

Summary An important feature of mechanism-based pharmacokinetic/pharmacodynamic (PK/PD) models is the identification of drug- and system-specific factors that determine the intensity and time-course of pharmacological effects. This provides an opportunity to integrate information obtained from in vitro bioassays and preclinical pharmacological studies in animals to anticipate the clinical and adverse responses to drugs in humans. The fact that contemporary PK/PD modeling continues to evolve and seeks to emulate systems level properties should provide enhanced capabilities to scale-up pharmacodynamic data. Critical steps in drug discovery and development, such as lead compound and first in human dose selection, may become more efficient with the implementation and further refinement of translational PK/PD modeling. In this review, we highlight fundamental principles in pharmacodynamics and the basic expectations for in vitro bioassays and traditional allometric scaling in PK/PD modeling. Discussion of PK/PD modeling efforts for recombinant human erythropoietin is also included as a case study showing the potential for advanced systems analysis to facilitate extrapolations and improve understanding of inter-species differences in drug responses. PMID:19252333

Mager, Donald E.; Woo, Sukyung; Jusko, William J.

2013-01-01

114

Coil optimization for low-field MRI: a dedicated process for small animal preclinical studies.  

PubMed

We demonstrate a method for the fast in vivo quantification of small volumes, down to 25?µL, using low-field magnetic resonance imaging (MRI) coils. The coils were designed so as to maximize the signal-to-noise ratio (SNR) in the images. For this we developed an analytical model for describing the variations of the SNR with coil design and with size/shape suited to the object under observation. Based on the conclusions drawn from the model, the coil parameters were chosen in order to reach an SNR close to the maximum. For the validation of the model, coils were finally characterized in terms of quality factor using saline phantoms. The coil design procedure is illustrated here with two examples: first, the quantification of about 200?µL of intradermal injected gel on rabbits with a single loop surface coil and second, the imaging of the intervertebral disks in rat tails using a small volume coil to detect possible lesions. Such studies would not have been feasible for the clinical low-field MRI system at our disposal using any of the commercially available medium-sized manufactured coils. As a result of this simple optimization procedure, a wide range of applications is accessible even at low magnetic fields, leading to new opportunities for low-cost, though efficient, preclinical studies. PMID:25359877

Feuillet, T; Seurin, M-J; Leveneur, O; Viguier, E; Beuf, O

2014-10-30

115

[Development and preclinical study of new generation virosomal split influenza vaccine "Grifor"].  

PubMed

New Russian virosomal split vaccine against influenza "Grifor" was developed. The vaccine is represented by mix of highly purified protective external and internal antigens of influenza A (H1N1 and H3N2) and B viruses. Developed technology of manufacture allowed to provide presentation of external antigens of influenza virus in the form of virosomes, and presentation of internal antigens in the form of micelles with maximal preservation of their antigenic activity. Using electron microscopy, electrophoresis in 10% polyacrilamide gel with sodium dodecyl sulfate, and polymerase chain reaction, morphologic and biochemical properties of the vaccine were studied. Preclinical study, including assessment of antigenic characteristics of "Grifor" vaccine compared to vaccine "Vaxigrip" (France), was performed. It was established that administration of the vaccine did not result in death of experimental animals, decrease of body mass, development of pathologic (including inflammatory, dystrophic and necrobiotic) changes in viscera or render adverse effects on blood hematologic and biochemical parameters and on the immune system. The vaccine was not pyrogenic and allergenic, did not have local irritating effects. Obtained results supported the appropriateness of conducting the clinical trials of "Grifor" vaccine on limited number of volunteers. PMID:19338232

Mel'nikov, S Ia; Zverev, V V; Korovkin, S A; Mironov, A N; Dyldina, N V; Mikha?lova, N A; Fa?zuloev, E B; Lotte, V D

2009-01-01

116

Preclinical Systemic Lupus Erythematosus.  

PubMed

Preclinical lupus encompasses a spectrum from enhanced SLE risk without clinical symptoms to individuals with autoantibodies and some SLE clinical features without meeting ACR classification. Studies have identified antibody and serological biomarkers years before disease onset. Incomplete lupus and undifferentiated connective tissue disease may occur during preclinical disease periods, but only 10-20% of these individuals transition to SLE and many have a mild disease course. Further studies are warranted to characterize biomarkers of early disease, identify individuals in need of close monitoring or preventive interventions, and elucidate mechanisms of disease pathogenesis without confounding factors of immunosuppressive medications or organ damage. PMID:25437281

Robertson, Julie M; James, Judith A

2014-11-01

117

Characterization of Activin/BMP2 chimera, AB204, formulated for preclinical studies.  

PubMed

AB204 is an Activin/BMP2 chimera, which has been found to exhibit a higher activity than Bone Morphogenetic Protein 2 (BMP2) in osteogenic activity. To prepare AB204 for its preclinical studies, AB204 has been characterized in various formulation buffers. We observed that AB204 purified by ion-exchange chromatography has low water solubility (2.0 mg/ml), whereas it has high water solubility (higher than 10.0 mg/ml) when purified by reverse-phase chromatography. Analysis of the purification procedures reveals that the buffer composition at the lyophilization step determines the solubility. Lyophilization from sodium acetate buffer at pH 4.5 resulted in formation of sodium hydroxide, which caused low solubility of AB204 by pH increase upon reconstitution in water. However, lyophilization from buffers, containing acetic acid or trifluoroacetic acid (TFA) rendered AB204 to be highly soluble. During the course of these analyses, we found a simple procedure to further reduce residual amount of TFA in the purified AB204. PMID:24555430

Ahn, Chihoon; Maslennikov, Innokentiy; Choi, Jung Youn; Oh, Hyosun; Cheong, Chaejoon; Choe, Senyon

2014-05-01

118

Behavioral models of impulsivity in relation to ADHD: Translation between clinical and preclinical studies  

PubMed Central

Impulsivity, broadly defined as action without foresight, is a component of numerous psychiatric illnesses including attention deficit/hyperactivity disorder (ADHD), mania and substance abuse. In order to investigate the mechanisms underpinning impulsive behavior, the nature of impulsivity itself needs to be defined in operational terms that can be used as the basis for empirical investigation. Due to the range of behaviors that the term impulsivity describes, it has been suggested that impulsivity is not a unitary construct, but encompasses a variety of related phenomena that may differ in their biological basis. Through fractionating impulsivity into these component parts, it has proved possible to devise different behavioral paradigms to measure various aspects of impulsivity in both humans and laboratory animals. This review describes and evaluates some of the current behavioral models of impulsivity developed for use with rodents based on human neuropsychological tests, focusing on the five-choice serial reaction time task, the stop-signal reaction time task and delay-discounting paradigms. Furthermore, the contributions made by preclinical studies using such methodology to improve our understanding of the neural and neurochemical basis of impulsivity and ADHD are discussed, with particular reference to the involvement of both the serotonergic and dopaminergic systems, and frontostriatal circuitry. PMID:16504359

Winstanley, Catharine A.; Eagle, Dawn M.; Robbins, Trevor W.

2006-01-01

119

Computed tomography-based rigidity analysis: a review of the approach in preclinical and clinical studies.  

PubMed

The assessment of fracture risk in patients afflicted with osseous neoplasms has long presented a problem for orthopedic oncologists. These patients are at risk for developing pathologic fractures through lytic defects in the appendicular and axial skeleton with devastating consequences on their quality of life. Lesions with a high risk of fracture may require prophylactic surgical stabilization, whereas low-risk lesions can be treated conservatively. Therefore, effective prevention of pathologic fractures depends on accurate assessment of fracture risk and is a critical step to avoid debilitating complications. Given the complex nature of osseous neoplasms, treatment requires a multidisciplinary approach; yet, little consensus regarding fracture risk assessment exists among physicians involved in the care of these patients. In order to improve the overall standard of care, specific criteria must be adopted to formulate consistent and accurate fracture risk predictions. However, clinicians make subjective assessments about fracture risk on plain radiographs using guidelines now recognized to be inaccurate. Osseous neoplasms alter both the material and geometric properties of bone; failure to account for changes in both of these parameters limits the accuracy of current fracture risk assessments. Rigidity, the capacity to resist deformation upon loading, is a structural property that integrates both the material and geometric properties of bone. Therefore, rigidity can be used as a mechanical assay of the changes induced by lytic lesions to the structural competency of bone. Using this principle, computed tomography (CT)-based structural rigidity analysis (CTRA) was developed and validated in a series of preclinical and clinical studies. PMID:25396051

Villa-Camacho, Juan C; Iyoha-Bello, Otatade; Behrouzi, Shohreh; Snyder, Brian D; Nazarian, Ara

2014-01-01

120

PRECLINICAL STUDIES A novel synthetic C-1 analogue of 7-deoxypancratistatin  

E-print Network

53 positive and negative human colorectal cancer cells by targeting the mitochondria: enhancement), isolated from the Hymenocallis littoralis plant, specifically induces apoptosis in many cancer cell lines cells. However, its availability for preclinical and clinical work is limited due to its low

Hudlicky, Tomas

121

Irinotecan delivery by microbubble-assisted ultrasound - A pilot preclinical study  

NASA Astrophysics Data System (ADS)

Irinotecan is conventionally used for the treatment of colorectal cancer. However, its administration is associated with severe side effects. Targeted drug delivery using ultrasound (US) combined with microbubbles offers new opportunities to increase the therapeutic effectiveness of antitumor treatment and to reduce toxic exposure to healthy tissues. The objective of this study is to investigate the safety and efficacy of in-vivo delivery of irinotecan by microbubble-assisted US in human glioblastoma model (U-87 MG). In order to validate the potential of this new method in-vivo, subcutaneous tumors were implanted in the flank of nude mouse and treated when they reached a volume of 100 mm3. In the first study, the measured volumes with caliper and anatomic ultrasound imaging were compared for the monitoring and the quantification of tumor growth during 27 days. Ultrasound imaging measurements were positively correlated to caliper measurements. The tumor treatment consisted of an i.v. injection of irinotecan (20 mg/kg) followed one hour later by i.v. administration of MM1 microbubble and an US insonation using a single-element transducer operating at 1MHz (400 kPa, 10 kHz PRF 40% DC, 3 min). The therapeutic efficacy was evaluated for 39 days by measuring the tumor volume before and after treatment using a caliper and based on ultrasound images using an 18 MHz probe (Vevo 2100). Our results showed that anatomical ultrasound imaging was as efficient as caliper for the monitoring and the quantification of tumor growth. Moreover, irinotecan delivery by sonoporation induced a significant decrease of glioblastoma tumor volume and an increase of tumor-doubling time compared to the tumor treated by irinotecan alone. In conclusion, this novel therapeutic approach has promising features since it can be used to reduce the injected drug dose and to achieve a better therapeutic efficacy.

Escoffre, Jean-Michel; Novell, Anthony; Serrière, Sophie; Bouakaz, Ayache

2012-11-01

122

Preclinical Toxicology and Biodistribution Studies of Recombinant Adeno-Associated Virus 1 Human Acid ?-Glucosidase  

PubMed Central

Abstract A biodistribution and toxicology study was performed to test the acute toxicities of intradiaphragmatic injection of a recombinant adeno-associated virus (rAAV) 2/1-human acid alpha-Glucosidase (hGAA) driven by a cytomegalovirus (CMV) promoter (rAAV1-CMV-hGAA) in New Zealand white rabbits and in the rodent Pompe disease model by injecting at the right quadriceps. Studies performed using fluoroscopy and AAV2-GFP demonstrated spread upon intradiaphragmatic injection, and the ability of AAV to infect and express acid ?-glucosidase (GAA) throughout the diaphragm. For the preclinical study, 10 rabbits (5 male, 5 female) were divided into two groups, vehicle control (Lactated Ringer's) and test article (1.5×1012 vector genomes [vg] rAAV1-CMV-hGAA), and euthanized on day 21. After direct visualization, the left hemidiaphragm was injected at three locations. There was up to a 2,500-fold increase in circulating anti-AAV1 antibodies directed to the vector capsids. In addition, up to an 18-fold increase in antibodies against the GAA protein was generated. Injection sites maintained up to 1.0×105 vg/?g genomic DNA (gDNA), while uninjected sites had up to 1.0×104 vg/?g gDNA. Vector DNA was present in blood at 24?hr postinjection at up to 1.0×106 vg/?g gDNA, followed by a decrease to 1.0×103 vg/?g gDNA at euthanization on day 21. Nominal amounts of vector DNA were present in peripheral organs, including the brain, spinal cord, gonads, and skeletal muscle. Upon histopathological examination, fibroplasias of the serosal surface were noted at diaphragm injections sites of both groups. In addition, an increase in mononuclear cell infiltration in the diaphragm and esophagus in vector-dosed animals was found. Elevated creatine phosphokinase levels, an indicator of muscle repair, was observed in all animals postprocedure but persisted in vector-injected rabbits until euthanization. A follow-up study suggested that this was directed against the human transgene expression in a foreign species. Overall, this study demonstrates diffusion of vector throughout the diaphragm after localized injections. PMID:24021025

Erger, Kirsten; Porvasnik, Stacy; Cossette, Travis; Roberts, Cheryl; Combee, Lynn; Islam, Saleem; Kelley, Jeffry; Cloutier, Denise; Clément, Nathalie; Abernathy, Corinne R.; Byrne, Barry J.

2013-01-01

123

High efficacy and the preservice reading teacher: A comparative study  

Microsoft Academic Search

The purpose of this study was to investigate the differential impact of two field experiences, tutoring and observing, on preservice teachers’ reading self-efficacy and content knowledge. Participants completed an adapted, reading version of The Teacher Sense of Efficacy Scale (TSES). Results showed that both groups reported growth in reading self-efficacy and content knowledge; however, there was only a marginally significant

Heather Rogers Haverback; Susan J. Parault

2011-01-01

124

Preclinical, phase I and pharmacokinetic studies with the dimethyl phenyltriazene CB10-277.  

PubMed Central

Decarbazine is an imidazole dimethyltriazene with reproducible activity in patients with metastatic melanoma. CB10-277 is a phenyl dimethyltriazene which, like dacarbazine, requires metabolic activation to its corresponding monomethyl species for antitumour activity. In preclinical models (human melanoma xenografts and transplantable rodent tumours) CB10-277 showed a similar spectrum and level of activity when compared to dacarbazine. Pharmacokinetic studies were performed with CB10-277 in mice treated i.v. at the LD10 (750 mg m-2) and plasma analysed by HPLC. The parent drug area under the plasma concentration vs time curve (AUC) was 142 mM x minutes. Drug metabolism occurred as evidenced by the HPLC identification of the monomethyl species (AUC = 8 mM x minutes) as well as other metabolites. A Phase I trial using a short infusion with doses repeated every 21 days has been performed. Thirty-six patients received 80 courses over a dose range of 80-6,000 mg m-2. The dose limiting toxicity was nausea and vomiting which occurred in 80% of the evaluable courses > or = 900 mg m-2. The only other common side effect was a flushing or warm sensation, which occurred in over 75% of courses at > or = 1,350 mg m-2. There were no hemodynamic consequences. Responses occurred in patients with melanoma (one complete, two partial, one mixed/11), sarcoma (one mixed/6) and carcinoid (one partial/l). Pharmacokinetics were performed in 46 courses. The CB10-277 AUC increased linearly with dose (r = 0.9203, P < 0.001) up to 700 mM x minutes at 6,000 mg m-2). Evidence of CB10-277 metabolism was observed, as in mice, by detection of the monomethyl species and other metabolites. However, the plasma levels of the monomethyl species in patients (1.8 and 3.7 mM x minutes at 6,000 mg m-2) were less than those predicted from studies in mice. Despite this, antitumour activity in dacarbazine sensitive histologies was observed and additional studies with CB10-277 are recommended. PMID:8431367

Foster, B. J.; Newell, D. R.; Carmichael, J.; Harris, A. L.; Gumbrell, L. A.; Jones, M.; Goodard, P. M.; Calvert, A. H.

1993-01-01

125

Radiopaque contrast media. XLIV - Preclinical studies with a new nonionic contrast agent.  

PubMed

L-5-alpha-hydroxypropionylamino-2,4,6-triiodoisophthalic acid di-(1,3-dihydroxy-2-propylamide), abbreviated Iopamidol, a new non-ionic water soluble contrast agent for angiography, myelography, ventriculography and for contrast reinforced computer-assisted axial tomography is described. Extensive preclinical testing showed favorable physico-chemical features of the new compound, low systemic toxicity, excellent cardiovascular and renal tolerability, very mild effects on the blood-brain barrier and on nervous tissue. PMID:923795

Felder, E; Pitrè, D; Tirone, P

1977-11-01

126

Temple study's pre-clinical data shows Angiocidin effective against leukemia  

Cancer.gov

Angiocidin, a novel tumor-inhibiting protein, has been shown to reduce acute myeloid leukemia (AML) cells in mice by almost two-thirds in pre-clinical experiments. A researcher from Temple University’s School of Medicine who discovered Angiocidin, presented the findings during the American Society of Hematology’s national meeting in Atlanta on Dec. 9. Temple University is home to the Fox Chase Cancer Center.

127

Cognition and beta-amyloid in preclinical Alzheimer's disease: data from the AIBL study.  

PubMed

The 'preclinical' phase of Alzheimer's disease is a future target for treatment, but additional research is essential to understand the relationship between ?-amyloid burden and cognition during this time. We investigated this relationship using a large sample of apparently healthy older adults (N=177), which also enabled examination of whether the relationship differed according to age, gender, years of education, apolipoprotein E status, and the presence of subjective memory complaints. In addition to episodic memory, a range of cognitive measures (global cognition, semantic memory, visuospatial performance, and executive function) were examined. Participants were aged over 60 years with no objective cognitive impairment and came from the imaging arm of the Australian Imaging, Biomarkers, and Lifestyle (AIBL) study of ageing. (11)C-PiB PET was used to measure ?-amyloid burden and a PiB 'cut-off' level of 1.5 was used to separate participants with low PiB retention from those with high PiB retention. Thirty-three percent of participants had a PiB positive scan. PiB positive participants were 5 years older, twice as likely to carry an apolipoprotein E ?4 allele, and their composite episodic memory was 0.26 SD worse than PiB negative volunteers. Linear regressions with ?-amyloid burden as a dichotomous predictor, revealed an interaction between ?-amyloid burden and gender, as well as age and education effects, in predicting episodic memory and visuospatial performance. In females, but not in males, increased ?-amyloid was related to worse episodic memory and visuospatial performance. Furthermore, an interaction between ?-amyloid burden and APOE status was found in predicting visuospatial performance, whereby there was a trend for increased ?-amyloid to relate to worse visuospatial performance for those without an APOE ?4 allele. There were no other main or interaction effects of ?-amyloid on any of the other composite cognitive measures. These cross-sectional findings suggest that ?-amyloid burden does not have a large effect on cognition in this subset of apparently healthy older people. The finding of gender differences deserves further research to answer definitively the important question of gender susceptibility to adverse cognitive effects from ?-amyloid. PMID:21529702

Pike, Kerryn E; Ellis, Kathryn A; Villemagne, Victor L; Good, Norm; Chételat, Gael; Ames, David; Szoeke, Cassandra; Laws, Simon M; Verdile, Giuseppe; Martins, Ralph N; Masters, Colin L; Rowe, Christopher C

2011-07-01

128

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

PubMed Central

Background The treatment options for patients requiring repair of a long segment of the urethra are limited by the availability of autologous tissues. We previously reported that acellular collagen-based tubularized constructs seeded with cells are able to repair small urethral defects in a rabbit model. Objective We explored the feasibility of engineering clinically relevant long urethras for surgical reconstruction in a canine preclinical model. Design, setting, and participants Autologous bladder epithelial and smooth muscle cells from 15 male dogs were grown and seeded onto preconfigured collagen-based tubular matrices (6 cm in length). The perineal urethral segment was removed in 21 male dogs. Urethroplasties were performed with tubularized collagen scaffolds seeded with cells in 15 animals. Tubularized constructs without cells were implanted in six animals. Serial urethrography and three-dimensional computed tomography (CT) scans were performed pre- and postoperatively at 1, 3, 6, and 12 mo. The animals were euthanized at their predetermined time points (three animals at 1 mo, and four at 3, 6, and 12 mo) for analyses. Outcome measurements and statistical analysis Statistical analysis of CT imaging and histology was not needed. Results and limitations CT urethrograms showed wide-caliber urethras without strictures in animals implanted with cell-seeded matrices. The urethral segments replaced with acellular scaffolds collapsed. Gross examination of the urethral implants seeded with cells showed normal-appearing tissue without evidence of fibrosis. Histologically, an epithelial cell layer surrounded by muscle fiber bundles was observed on the cell-seeded constructs, and cellular organization increased over time. The epithelial and smooth muscle phenotypes were confirmed using antibodies to pancytokeratins AE1/AE3 and smooth muscle–specific desmin. Formation of an epithelial cell layer occurred in the unseeded constructs, but few muscle fibers formed. Conclusions Cell-seeded tubularized collagen scaffolds can be used to repair long urethral defects, whereas scaffolds without cells lead to poor tissue development and strictures. This study demonstrates that long tissue-engineered tubularized urethral segments may be used for urethroplasty in patients. PMID:22877501

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

2012-01-01

129

Synthesis, characterization and preclinical studies of two-photon-activated targeted PDT therapeutic triads  

NASA Astrophysics Data System (ADS)

Photodynamic therapy (PDT) continues to evolve into a mature clinical treatment of a variety of cancer types as well as age-related macular degeneration of the eye. However, there are still aspects of PDT that need to be improved in order for greater clinical acceptance. While a number of new PDT photo-sensitizers, sometimes referred to as second- or third- generation therapeutic agents, are currently under clinical investigation, the direct treatment through the skin of subcutaneous tumors deeper than 5 mm remains problematic. Currently approved PDT porphyrin photo-sensitizers, as well as several modified porphyrins (e.g. chlorins, bacteriochlorins, etc.) that are under clinical investigation can be activated at 630-730 nm, but none above 800 nm. It would be highly desirable if new PDT paradigms could be developed that would allow photo-activation deep in the tissue transparency window in the Near-infrared (NIR) above 800 nm to reduce scattering and absorption phenomena that reduce deep tissue PDT efficacy. Rasiris and MPA Technologies have developed new porphyrins that have greatly enhanced two-photon absorption ( P A ) cross-sections and can be activated deep in the NIR (ca. 780-850 nm). These porphyrins can be incorporated into a therapeutic triad that also employs an small molecule targeting agent that directs the triad to over-expressed tumor receptor sites, and a NIR onephoton imaging agent that allows tracking the delivery of the triad to the tumor site, as well as clearance of excess triad from healthy tissue prior to the start of PDT treatment. We are currently using these new triads in efficacy studies with a breast cancer cell line that has been transfected with luciferase genes that allow implanted tumor growth and post- PDT treatment efficacy studies in SCID mouse models by following the rise and decay of the bioluminescence signal. We have also designed highly absorbing and scattering collagen breast cancer phantoms in which we have demonstrated dramatic cell kill to a depth of at least 4 cm. We have also demonstrated that at the wavelength and laser fluences used in the treatment of implanted tumors in the mouse mammary fat pads, there is little, if any, damage to the skin or internal mouse organs. In addition, we have also demonstrated that the implanted tumors can be treated to a depth of more than 1 cm by direct radiation through the dorsal side of the mouse.

Spangler, C. W.; Starkey, J. R.; Rebane, A.; Meng, F.; Gong, A.; Drobizhev, M.

2006-02-01

130

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

PubMed Central

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

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

2014-01-01

131

Systematic Approach to Remediation in Basic Science Knowledge for Preclinical Students: A case study  

NASA Astrophysics Data System (ADS)

Remediation of pre-clerkship students for deficits in basic science knowledge should help them overcome their learning deficiencies prior to clerkship. However, very little is known about remediation in basic science knowledge during pre-clerkship. This study utilized the program theory framework to collect and organize mixed methods data of the remediation plan for pre-clerkship students who failed their basic science cognitive examinations in a Canadian medical school. This plan was analyzed using a logic model narrative approach and compared to literature on the learning theories. The analysis showed a remediation plan that was strong on governance and verification of scores, but lacked: clarity and transparency of communication, qualified remedial tutors, individualized diagnosis of learner's deficits, and student centered learning. Participants admitted uncertainty about the efficacy of the remediation process. A remediation framework is proposed that includes student-centered participation, individualized learning plan and activities, deliberate practice, feedback, reflection, and rigorous reassessment.

Amara, Francis

132

Employing a gain-of-function factor IX variant R338L to advance the efficacy and safety of hemophilia B human gene therapy: Preclinical evaluation supporting an ongoing AAV clinical trial.  

PubMed

Vector capsid dose-dependent inflammation of transduced liver has limited the ability of AAV factor IX (FIX) gene therapy vectors to reliably convert severe to mild hemophilia B in human clinical trials. These trials also identified the need to understand AAV neutralizing antibodies and AAV empty capsids in regards to their impact on clinical success. To address these safety concerns, we have used a scalable manufacturing process to produce GMP grade AAV8 expressing the FIXR338L gain-of-function variant with minimal (<10%) empty capsid and have performed comprehensive dose/response, bio-distribution and safety evaluations in clinically-relevant hemophilia models. The scAAV8.FIXR338L vector produced greater than 6-fold increased FIX specific activity compared to wild type FIX and demonstrated linear dose-responses from doses that produced 2% to 500% FIX activity, associated with dose-dependent hemostasis in a tail transection bleeding challenge. More importantly, using a bleeding model that closely mimics the clinical morbidity of hemophilic arthropathy, mice that received the scAAV8.FIXR338L vector developed minimal histopathologic findings of synovitis following hemarthosis, when compared with mice that received identical doses of wild type FIX vector. Hemostatically normal mice (n=20) and hemophilic (n=88) mice developed no FIX antibodies after peripheral I.V. vector delivery. No CD8+ T cell liver infiltrates were observed, despite the marked tropism of scAAV8.FIXR338L for the liver in a comprehensive biodistribution evaluation (N = 60 animals). With respect to the role of empty capsids, we demonstrated that in vivo FIXR338L expression was not influenced by the presence of AAV empty particles, either in the presence or absence of varying titers of AAV8-neutralizing antibodies. Necropsy of FIX-/- mice at 8-10 months after vector delivery revealed no microvascular or macrovascular thrombosis in mice expressing FIXR338L (plasma FIX activity 100-500%). These preclinical studies demonstrate a safety:efficacy profile supporting an ongoing Phase 1/2 human clinical trial of the scAAV8.FIXR338L vector (designated BAX335). PMID:25419787

Monahan, Paul Edward; Sun, Junjiang; Gui, Tong; Hu, Genlin; Hannah, William B; Wichlan, David Gerrard; Wu, Zhijian; Grieger, Joshua C; Li, Chengwen; Suwanmanee, Thipa; Stafford, Darrel W; Booth, Carmen J; Samulski, Jade J; Kafri, Tal; McPhee, Scott W J; Samulski, R Jude

2014-11-24

133

Nanomedicines for cancer therapy: state-of-the-art and limitations to pre-clinical studies that hinder future developments.  

PubMed

The ability to efficiently deliver a drug or gene to a tumor site is dependent on a wide range of factors including circulation time, interactions with the mononuclear phagocyte system, extravasation from circulation at the tumor site, targeting strategy, release from the delivery vehicle, and uptake in cancer cells. Nanotechnology provides the possibility of creating delivery systems where the design constraints are decoupled, allowing new approaches for reducing the unwanted side effects of systemic delivery, increasing tumor accumulation, and improving efficacy. The physico-chemical properties of nanoparticle-based delivery platforms introduce additional complexity associated with pharmacokinetics, tumor accumulation, and biodistribution. To assess the impact of nanoparticle-based delivery systems, we first review the design strategies and pharmacokinetics of FDA-approved nanomedicines. Next we review nanomedicines under development, summarizing the range of nanoparticle platforms, strategies for targeting, and pharmacokinetics. We show how the lack of uniformity in preclinical trials prevents systematic comparison and hence limits advances in the field. PMID:25202689

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

2014-01-01

134

Nanomedicines for cancer therapy: state-of-the-art and limitations to pre-clinical studies that hinder future developments  

PubMed Central

The ability to efficiently deliver a drug or gene to a tumor site is dependent on a wide range of factors including circulation time, interactions with the mononuclear phagocyte system, extravasation from circulation at the tumor site, targeting strategy, release from the delivery vehicle, and uptake in cancer cells. Nanotechnology provides the possibility of creating delivery systems where the design constraints are decoupled, allowing new approaches for reducing the unwanted side effects of systemic delivery, increasing tumor accumulation, and improving efficacy. The physico-chemical properties of nanoparticle-based delivery platforms introduce additional complexity associated with pharmacokinetics, tumor accumulation, and biodistribution. To assess the impact of nanoparticle-based delivery systems, we first review the design strategies and pharmacokinetics of FDA-approved nanomedicines. Next we review nanomedicines under development, summarizing the range of nanoparticle platforms, strategies for targeting, and pharmacokinetics. We show how the lack of uniformity in preclinical trials prevents systematic comparison and hence limits advances in the field. PMID:25202689

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

2014-01-01

135

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

PubMed

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. PMID:23069751

Neigh, G N; Ritschel, L A; Kilpela, L S; Harrell, C S; Bourke, C H

2013-09-26

136

The in vivo efficacy and side effect pharmacology of GS-5759, a novel bifunctional phosphodiesterase 4 inhibitor and long-acting ? 2-adrenoceptor agonist in preclinical animal species.  

PubMed

Bronchodilators are a central therapy for symptom relief in respiratory diseases such as chronic obstructive pulmonary disease (COPD) and asthma, with inhaled ? 2-adrenoceptor agonists and anticholinergics being the primary treatments available. The present studies evaluated the in vivo pharmacology of (R)-6-[[3-[[4-[5-[[2-Hydroxy-2-(8-hydroxy-2-oxo-1,2-dihydroquinolin-5-yl)ethyl]amino]pent-1-ynyl]phenyl]carbamoyl]phenyl]sulfonyl]-4-[(3-methoxyphenyl)amino]-8-methylquinoline-3-carboxamide (GS-5759), a novel bifunctional compound with both phosphodiesterase 4 (PDE4) inhibitor and long-acting ? 2-adrenoceptor agonist (LABA) activity, which has been optimized for inhalation delivery. GS-5759 dose-dependently inhibited pulmonary neutrophilia in a lipopolysaccharide (LPS) aerosol challenge model of inflammation in rats with an ED50 ? 10 ?g/kg. GS-5759 was also a potent bronchodilator with an ED50 of 0.09 ?g/kg in guinea pigs and 3.4 ?g/kg in dogs after methylcholine (MCh) and ragweed challenges respectively. In cynomolgus monkeys, GS-5759 was dosed as a fine-particle dry powder and was efficacious in the same dose range in both MCh and LPS challenge models, with an ED50 = 70 ?g/kg for bronchodilation and ED50 = 4.9 ?g/kg for inhibition of LPS-induced pulmonary neutrophilia. In models to determine therapeutic index (T.I.), efficacy for bronchodilation was evaluated against increased heart rate and GS-5759 had a T.I. of 700 in guinea pigs and >31 in dogs. In a ferret model of emesis, no emesis was seen at doses several orders of magnitude greater than the ED50 observed in the rat LPS inflammation model. GS-5759 is a bifunctional molecule developed for the treatment of COPD, which has both bronchodilator and anti-inflammatory activity and has the potential for combination as a triple therapy with a second compound, within a single inhalation device. PMID:25505595

Salmon, Michael; Tannheimer, Stacey L; Gentzler, Terry T; Cui, Zhi-Hua; Sorensen, Eric A; Hartsough, Kimberly C; Kim, Musong; Purvis, Lafe J; Barrett, Edward G; McDonald, Jacob D; Rudolph, Karin; Doyle-Eisele, Melanie; Kuehl, Philip J; Royer, Christopher M; Baker, William R; Phillips, Gary B; Wright, Clifford D

2014-08-01

137

The oral HDAC inhibitor pracinostat (SB939) is efficacious and synergistic with the JAK2 inhibitor pacritinib (SB1518) in preclinical models of AML  

PubMed Central

Acute myeloid leukemia (AML) is currently treated with aggressive chemotherapy that is not well tolerated in many elderly patients, hence the unmet medical need for effective therapies with less toxicity and better tolerability. Inhibitors of FMS-like tyrosine kinase 3 (FLT3), JAK2 and histone deacetylase inhibitors (HDACi) have been tested in clinical studies, but showed only moderate single-agent activity. High efficacy of the HDACi pracinostat treating AML and synergy with the JAK2/FLT3 inhibitor pacritinib is demonstrated. Both compounds inhibit JAK-signal transducer and activator of transcription (STAT) signaling in AML cells with JAK2V617F mutations, but also diminish FLT3 signaling, particularly in FLT3-ITD (internal tandem duplication) cell lines. In vitro, this combination led to decreased cell proliferation and increased apoptosis. The synergy translated in vivo in two different AML models, the SET-2 megakaryoblastic AML mouse model carrying a JAK2V617F mutation, and the MOLM-13 model of FLT3-ITD-driven AML. Pracinostat and pacritinib in combination showed synergy on tumor growth, reduction of metastases and synergistically decreased JAK2 or FLT signaling, depending on the cellular context. In addition, several plasma cytokines/growth factors/chemokines triggered by the tumor growth were normalized, providing a rationale for combination therapy with an HDACi and a JAK2/FLT3 inhibitor for the treatment of AML patients, particularly those with FLT3 or JAK2 mutations. PMID:22829971

Novotny-Diermayr, V; Hart, S; Goh, K C; Cheong, A; Ong, L-C; Hentze, H; Pasha, M K; Jayaraman, R; Ethirajulu, K; Wood, J M

2012-01-01

138

The oral HDAC inhibitor pracinostat (SB939) is efficacious and synergistic with the JAK2 inhibitor pacritinib (SB1518) in preclinical models of AML.  

PubMed

Acute myeloid leukemia (AML) is currently treated with aggressive chemotherapy that is not well tolerated in many elderly patients, hence the unmet medical need for effective therapies with less toxicity and better tolerability. Inhibitors of FMS-like tyrosine kinase 3 (FLT3), JAK2 and histone deacetylase inhibitors (HDACi) have been tested in clinical studies, but showed only moderate single-agent activity. High efficacy of the HDACi pracinostat treating AML and synergy with the JAK2/FLT3 inhibitor pacritinib is demonstrated. Both compounds inhibit JAK-signal transducer and activator of transcription (STAT) signaling in AML cells with JAK2(V617F) mutations, but also diminish FLT3 signaling, particularly in FLT3-ITD (internal tandem duplication) cell lines. In vitro, this combination led to decreased cell proliferation and increased apoptosis. The synergy translated in vivo in two different AML models, the SET-2 megakaryoblastic AML mouse model carrying a JAK2(V617F) mutation, and the MOLM-13 model of FLT3-ITD-driven AML. Pracinostat and pacritinib in combination showed synergy on tumor growth, reduction of metastases and synergistically decreased JAK2 or FLT signaling, depending on the cellular context. In addition, several plasma cytokines/growth factors/chemokines triggered by the tumor growth were normalized, providing a rationale for combination therapy with an HDACi and a JAK2/FLT3 inhibitor for the treatment of AML patients, particularly those with FLT3 or JAK2 mutations. PMID:22829971

Novotny-Diermayr, V; Hart, S; Goh, K C; Cheong, A; Ong, L-C; Hentze, H; Pasha, M K; Jayaraman, R; Ethirajulu, K; Wood, J M

2012-05-01

139

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

PubMed Central

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

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

2010-01-01

140

A gender study investigating physics self-efficacy  

NASA Astrophysics Data System (ADS)

The underrepresentation of women in physics has been well documented and a source of concern for both policy makers and educators. My dissertation focuses on understanding the role self-efficacy plays in retaining students, particularly women, in introductory physics. I use an explanatory mixed methods approach to first investigate quantitatively the influence of self-efficacy in predicting success and then to qualitatively explore the development of self-efficacy. In the initial quantitative studies, I explore the utility of self-efficacy in predicting the success of introductory physics students, both women and men. Results indicate that self-efficacy is a significant predictor of success for all students. I then disaggregate the data to examine how self-efficacy develops differently for women and men in the introductory physics course. Results show women rely on different sources of self-efficacy than do men, and that a particular instructional environment, Modeling Instruction, has a positive impact on these sources of self-efficacy. In the qualitative phase of the project, this dissertation focuses on the development of self-efficacy. Using the qualitative tool of microanalysis, I introduce a methodology for understanding how self-efficacy develops moment-by-moment using the lens of self-efficacy opportunities. I then use the characterizations of self-efficacy opportunities to focus on a particular course environment and to identify and describe a mechanism by which Modeling Instruction impacts student self-efficacy. Results indicate that the emphasizing the development and deployment of models affords opportunities to impact self-efficacy. The findings of this dissertation indicate that introducing key elements into the classroom, such as cooperative group work, model development and deployment, and interaction with the instructor, create a mechanism by which instructors can impact the self-efficacy of their students. Results from this study indicate that creating a model to impact the retention rates of women in physics should include attending to self-efficacy and designing activities in the classroom that create self-efficacy opportunities.

Sawtelle, Vashti

141

High Efficacy and the Preservice Reading Teacher: A Comparative Study  

ERIC Educational Resources Information Center

The purpose of this study was to investigate the differential impact of two field experiences, tutoring and observing, on preservice teachers' reading self-efficacy and content knowledge. Participants completed an adapted, reading version of The Teacher Sense of Efficacy Scale (TSES). Results showed that both groups reported growth in reading…

Haverback, Heather Rogers; Parault, Susan J.

2011-01-01

142

Application of micro-CT assessment of 3-D bone microstructure in preclinical and clinical studies.  

PubMed

As the mechanical competence of trabecular bone is a function of its apparent density and 3-D distribution, assessment of 3-D trabecular structural characteristics may improve our ability to understand the pathophysiology of osteoporosis, to test the efficacy of pharmaceutical intervention, and to estimate bone biomechanical properties. We have studied ovariectomy-induced osteopenia in rats and its treatment with agents such as estrogen and sodium fluoride. We have demonstrated that 3-D micro-computed tomography (microCT) can directly quantify mouse trabecular and cortical bone structure with an isotropic resolution of 6 microm(3). MicroCT is also useful for studying osteoporosis in mice and phenotypes of mice with gene manipulation, such as SHIP-knockout mice, which are severely osteoporotic due to increased numbers of hyperresorptive osteoclasts, PTHrP heterozygous-null mice, and mice with Zmpste24 deficiency. MicroCT can quantify osteogenesis in mouse Ilizarov leg-lengthening procedures, osteoconduction in a rat cranial defect model, and structural changes in arthritic rabbits, rats, and mice. In clinical studies, we evaluated longitudinal changes in the iliac crests. Paired bone biopsies from the same premenopausal and postmenopausal women showed the changes in 3-D trabecular structure, such as decreased trabecular thickness, shifting of trabecular model from platelike structure to rodlike structure, and decreased degree of anisotropy were remarkable. Treatment with PTH in postmenopausal women with osteoporosis significantly improved trabecular morphology with a shift toward a more platelike structure, increased trabecular connectivity density, and increased cortical thickness. Paired bone biopsy specimens from the iliac crest in postmenopausal women with osteoporosis before and an average of 2 years after beginning of estrogen replacement therapy demonstrated that posttreatment biopsies showed a significant change in the ratio of plates to rods and statistically insignificant changes in other 3-D trabecular parameters. Thus, microCT can characterize 3-D structure of various animal models, and the longitudinal changes in 3-D bone microarchitectural integrity that deteriorates in the transmenopausal period, is preserved with HRT, and is improved with PTH treatment in postmenopausal women. PMID:15984427

Jiang, Yebin; Zhao, Jenny; Liao, Er-Yuan; Dai, Ru-Chun; Wu, Xian-Ping; Genant, Harry K

2005-01-01

143

Magnetic resonance imaging (MRI)-guided transurethral ultrasound therapy of the prostate: a preclinical study with radiological and pathological correlation using customised MRI-based moulds  

PubMed Central

Objective To characterise the feasibility and safety of a novel transurethral ultrasound (US)-therapy device combined with real-time multi-plane magnetic resonance imaging (MRI)-based temperature monitoring and temperature feedback control, to enable spatiotemporally precise regional ablation of simulated prostate gland lesions in a preclinical canine model. To correlate ablation volumes measured with intra-procedural cumulative thermal damage estimates, post-procedural MRI, and histopathology. Materials and methods Three dogs were treated with three targeted ablations each, using a prototype MRI-guided transurethral US-therapy system (Philips Healthcare, Vantaa, Finland). MRI provided images for treatment planning, guidance, real-time multi-planar thermometry, as well as post-treatment evaluation of efficacy. After treatment, specimens underwent histopathological analysis to determine the extent of necrosis and cell viability. Statistical analyses (Pearson’s correlation, Student’s t-test) were used to evaluate the correlation between ablation volumes measured with intra-procedural cumulative thermal damage estimates, post-procedural MRI, and histopathology. Results MRI combined with a transurethral US-therapy device enabled multi-planar temperature monitoring at the target as well as in surrounding tissues, allowing for safe, targeted, and controlled ablations of prescribed lesions. Ablated volumes measured by cumulative thermal dose positively correlated with volumes determined by histopathological analysis (r2 0.83, P < 0.001). Post-procedural contrast-enhanced and diffusion-weighted MRI showed a positive correlation with non-viable areas on histopathological analysis (r2 0.89, P < 0.001, and r20.91, P = 0.003, respectively). Additionally, there was a positive correlation between ablated volumes according to cumulative thermal dose and volumes identified on post-procedural contrast-enhanced MRI (r2 0.77, P < 0.01). There was no difference in mean ablation volumes assessed with the various analysis methods (P > 0.05, Student’s t-test). Conclusions MRI-guided transurethral US therapy enabled safe and targeted ablations of prescribed lesions in a preclinical canine prostate model. Ablation volumes were reliably predicted by intra- and post-procedural imaging. Clinical studies are needed to confirm the feasibility, safety, oncological control, and functional outcomes of this therapy in patients in whom focal therapy is indicated. PMID:23746198

Partanen, Ari; Yerram, Nitin K.; Trivedi, Hari; Dreher, Matthew R.; Oila, Juha; Hoang, Anthony N.; Volkin, Dmitry; Nix, Jeffrey; Turkbey, Baris; Bernardo, Marcelino; Haines, Diana C.; Benjamin, Compton J.; Linehan, W. Marston; Choyke, Peter; Wood, Bradford J.; Ehnholm, Gösta J.; Venkatesan, Aradhana M.; Pinto, Peter A.

2013-01-01

144

Reproducibility of results in preclinical studies: a perspective from the bone field.  

PubMed

The biomedical research enterprise-and the public support for it-is predicated on the belief that discoveries and the conclusions drawn from them can be trusted to build a body of knowledge which will be used to improve human health. As in all other areas of scientific inquiry, knowledge and understanding grow by layering new discoveries upon earlier ones. The process self-corrects and distills knowledge by discarding false ideas and unsubstantiated claims. Although self-correction is inexorable in the long-term, in recent years biomedical scientists and the public alike have become alarmed and deeply troubled by the fact that many published results cannot be reproduced. The chorus of concern reached a high pitch with a recent commentary from the NIH Director, Francis S. Collins, and Principal Deputy Director, Lawrence A. Tabak, and their announcement of specific plans to enhance reproducibility of preclinical research that relies on animal models. In this invited perspective, we highlight the magnitude of the problem across biomedical fields and address the relevance of these concerns to the field of bone and mineral metabolism. We also suggest how our specialty journals, our scientific organizations, and our community of bone and mineral researchers can help to overcome this troubling trend. PMID:24916175

Manolagas, Stavros C; Kronenberg, Henry M

2014-10-01

145

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

PubMed

Infection with hepatitis B virus (HBV) may lead to subclinical, acute or chronic hepatitis. In the prevaccination era, HBV infections were endemic due to frequent mother to child transmission in large regions of the world. However, there are still estimated 240 million chronic HBV carriers today and ca. 620,000 patients die per year due to HBV-related liver diseases. Recommended treatment of chronic hepatitis B with interferon-? and/or nucleos(t)ide analogues does not lead to satisfactory results. Induction of HBV-specific T cells by therapeutic vaccination or immunomodulation may be an innovative strategy to overcome virus persistence. Vaccination with commercially available HBV vaccines in patients with or without therapeutic reduction of viral load did not result in effective immune control of HBV infection, suggesting that combination of antiviral treatment with new formulations of therapeutic vaccines is needed. The woodchuck (Marmota monax) and its HBV-like woodchuck hepatitis virus are a useful preclinical animal model for developing new therapeutic approaches in chronic hepadnaviral infections. Several innovative approaches combining antiviral treatments using nucleos(t)ide analogues, with prime-boost vaccination using DNA vaccines, new hepadnaviral antigens or recombinant adenoviral vectors were tested in the woodchuck model. In this review, we summarize these encouraging results obtained with these therapeutic vaccines. In addition, we present potential innovations in immunostimulatory strategies by blocking the interaction of the inhibitory programmed death receptor 1 with its ligand in this animal model. PMID:25535101

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

2015-02-01

146

Fabry disease: preclinical studies demonstrate the effectiveness of alpha-galactosidase A replacement in enzyme-deficient mice.  

PubMed

Preclinical studies of enzyme-replacement therapy for Fabry disease (deficient alpha-galactosidase A [alpha-Gal A] activity) were performed in alpha-Gal A-deficient mice. The pharmacokinetics and biodistributions were determined for four recombinant human alpha-Gal A glycoforms, which differed in sialic acid and mannose-6-phosphate content. The plasma half-lives of the glycoforms were approximately 2-5 min, with the more sialylated glycoforms circulating longer. After intravenous doses of 1 or 10 mg/kg body weight were administered, each glycoform was primarily recovered in the liver, with detectable activity in other tissues but not in the brain. Normal or greater activity levels were reconstituted in various tissues after repeated doses (10 mg/kg every other day for eight doses) of the highly sialylated AGA-1 glycoform; 4 d later, enzyme activity was retained in the liver and spleen at levels that were, respectively, 30% and 10% of that recovered 1 h postinjection. Importantly, the globotriaosylceramide (GL-3) substrate was depleted in various tissues and plasma in a dose-dependent manner. A single or repeated doses (every 48 h for eight doses) of AGA-1 at 0.3-10.0 mg/kg cleared hepatic GL-3, whereas higher doses were required for depletion of GL-3 in other tissues. After a single dose of 3 mg/kg, hepatic GL-3 was cleared for > or =4 wk, whereas cardiac and splenic GL-3 reaccumulated at 3 wk to approximately 30% and approximately 10% of pretreatment levels, respectively. Ultrastructural studies demonstrated reduced GL-3 storage posttreatment. These preclinical animal studies demonstrate the dose-dependent clearance of tissue and plasma GL-3 by administered alpha-Gal A, thereby providing the in vivo rationale-and the critical pharmacokinetic and pharmacodynamic data-for the design of enzyme-replacement trials in patients with Fabry disease. PMID:11115376

Ioannou, Y A; Zeidner, K M; Gordon, R E; Desnick, R J

2001-01-01

147

A new mathematical approach for the estimation of the AUC and its variability under different experimental designs in preclinical studies.  

PubMed

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. PMID:21268234

Navarro-Fontestad, Carmen; González-Álvarez, Isabel; Fernández-Teruel, Carlos; Bermejo, Marival; Casabó, Vicente Germán

2012-01-01

148

Two years later: journals are not yet enforcing the ARRIVE guidelines on reporting standards for pre-clinical animal studies.  

PubMed

There is growing concern that poor experimental design and lack of transparent reporting contribute to the frequent failure of pre-clinical animal studies to translate into treatments for human disease. In 2010, the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines were introduced to help improve reporting standards. They were published in PLOS Biology and endorsed by funding agencies and publishers and their journals, including PLOS, Nature research journals, and other top-tier journals. Yet our analysis of papers published in PLOS and Nature journals indicates that there has been very little improvement in reporting standards since then. This suggests that authors, referees, and editors generally are ignoring guidelines, and the editorial endorsement is yet to be effectively implemented. PMID:24409096

Baker, David; Lidster, Katie; Sottomayor, Ana; Amor, Sandra

2014-01-01

149

Two Years Later: Journals Are Not Yet Enforcing the ARRIVE Guidelines on Reporting Standards for Pre-Clinical Animal Studies  

PubMed Central

There is growing concern that poor experimental design and lack of transparent reporting contribute to the frequent failure of pre-clinical animal studies to translate into treatments for human disease. In 2010, the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines were introduced to help improve reporting standards. They were published in PLOS Biology and endorsed by funding agencies and publishers and their journals, including PLOS, Nature research journals, and other top-tier journals. Yet our analysis of papers published in PLOS and Nature journals indicates that there has been very little improvement in reporting standards since then. This suggests that authors, referees, and editors generally are ignoring guidelines, and the editorial endorsement is yet to be effectively implemented. PMID:24409096

Baker, David; Lidster, Katie; Sottomayor, Ana; Amor, Sandra

2014-01-01

150

Ramucirumab: preclinical research and clinical development  

PubMed Central

Ramucirumab (IMC-1121B, LY3009806), a fully humanized monoclonal antibody directed against the extracellular domain of vascular endothelial growth factor receptor 2 (VEGFR-2), is a new therapeutic option that selectively inhibits the human VEGFR-2 with a much greater affinity than its natural ligands. Based on the promising results of both preclinical and early clinical studies, ramucirumab has been tested in different tumor types either alone or in combination with chemotherapy. While it has recently been granted its first US Food and Drug Administration approval for use as a single agent in patients with advanced or metastatic gastric cancer or gastroesophageal junction carcinoma, its role for metastatic breast cancer or advanced non-small-cell lung cancer is still debated. The aims of this review are to recall and discuss the most significant preclinical and clinical studies that led to the development of ramucirumab and to present the results of the randomized clinical trials that have tested its efficacy in different malignancies, including gastric and lung cancer. PMID:25378934

Aprile, Giuseppe; Rijavec, Erika; Fontanella, Caterina; Rihawi, Karim; Grossi, Francesco

2014-01-01

151

Self?efficacy and statistics performance among Sport Studies students  

Microsoft Academic Search

The present study explored predictive paths between performance accomplishments, self?efficacy, and performance among Sport Studies students taking a Level 1 statistics module. Fifty?eight Level 1 Sport Studies undergraduate degree students completed a 44?item self?efficacy measure and an assessment of perceived academic success at the start of the module. Self?assessed worksheets taken in weeks 4 and 5 were used as a

Ross Hall

2004-01-01

152

N-Aryl Piperazine Metabotropic Glutamate Receptor 5 Positive Allosteric Modulators Possess Efficacy in Preclinical Models of NMDA Hypofunction and Cognitive Enhancement  

PubMed Central

Impaired transmission through glutamatergic circuits has been postulated to play a role in the underlying pathophysiology of schizophrenia. Furthermore, inhibition of the N-methyl-d-aspartate (NMDA) subtype of ionotropic glutamate receptors (NMDAR) induces a syndrome that recapitulates many of the symptoms observed in patients with schizophrenia. Selective activation of metabotropic glutamate receptor subtype 5 (mGlu5) may provide a novel therapeutic approach for treatment of symptoms associated with schizophrenia through facilitation of transmission through central glutamatergic circuits. Here, we describe the characterization of two novel N-aryl piperazine mGlu5 positive allosteric modulators (PAMs): 2-(4-(2-(benzyloxy)acetyl)piperazin-1-yl)benzonitrile (VU0364289) and 1-(4-(2,4-difluorophenyl)piperazin-1-yl)-2-((4-fluorobenzyl)oxy)ethanone (DPFE). VU0364289 and DPFE induced robust leftward shifts in the glutamate concentration-response curves for Ca2+ mobilization and extracellular signal-regulated kinases 1 and 2 phosphorylation. Both PAMs displayed micromolar affinity for the common mGlu5 allosteric binding site and high selectivity for mGlu5. VU0364289 and DPFE possessed suitable pharmacokinetic properties for dosing in vivo and produced robust dose-related effects in reversing amphetamine-induced hyperlocomotion, a preclinical model predictive of antipsychotic-like activity. In addition, DPFE enhanced acquisition of contextual fear conditioning in rats and reversed behavioral deficits in a mouse model of NMDAR hypofunction. In contrast, DPFE had no effect on reversing apomorphine-induced disruptions of prepulse inhibition of the acoustic startle reflex. These mGlu5 PAMs also increased monoamine levels in the prefrontal cortex, enhanced performance in a hippocampal-mediated memory task, and elicited changes in electroencephalogram dynamics commensurate with procognitive effects. Collectively, these data support and extend the role for the development of novel mGlu5 PAMs for the treatment of psychosis and cognitive deficits observed in individuals with schizophrenia. PMID:23965381

Gregory, K.J.; Herman, E.J.; Ramsey, A.J.; Hammond, A.S.; Byun, N.E.; Stauffer, S.R.; Manka, J.T.; Jadhav, S.; Bridges, T.M.; Weaver, C.D.; Niswender, C.M.; Steckler, T.; Drinkenburg, W.H.; Ahnaou, A.; Lavreysen, H.; Macdonald, G.J.; Bartolomé, J.M.; Mackie, C.; Hrupka, B.J.; Caron, M.G.; Daigle, T.L.; Lindsley, C.W.; Conn, P.J.

2013-01-01

153

N-aryl piperazine metabotropic glutamate receptor 5 positive allosteric modulators possess efficacy in preclinical models of NMDA hypofunction and cognitive enhancement.  

PubMed

Impaired transmission through glutamatergic circuits has been postulated to play a role in the underlying pathophysiology of schizophrenia. Furthermore, inhibition of the N-methyl-d-aspartate (NMDA) subtype of ionotropic glutamate receptors (NMDAR) induces a syndrome that recapitulates many of the symptoms observed in patients with schizophrenia. Selective activation of metabotropic glutamate receptor subtype 5 (mGlu5) may provide a novel therapeutic approach for treatment of symptoms associated with schizophrenia through facilitation of transmission through central glutamatergic circuits. Here, we describe the characterization of two novel N-aryl piperazine mGlu5 positive allosteric modulators (PAMs): 2-(4-(2-(benzyloxy)acetyl)piperazin-1-yl)benzonitrile (VU0364289) and 1-(4-(2,4-difluorophenyl)piperazin-1-yl)-2-((4-fluorobenzyl)oxy)ethanone (DPFE). VU0364289 and DPFE induced robust leftward shifts in the glutamate concentration-response curves for Ca(2+) mobilization and extracellular signal-regulated kinases 1 and 2 phosphorylation. Both PAMs displayed micromolar affinity for the common mGlu5 allosteric binding site and high selectivity for mGlu5. VU0364289 and DPFE possessed suitable pharmacokinetic properties for dosing in vivo and produced robust dose-related effects in reversing amphetamine-induced hyperlocomotion, a preclinical model predictive of antipsychotic-like activity. In addition, DPFE enhanced acquisition of contextual fear conditioning in rats and reversed behavioral deficits in a mouse model of NMDAR hypofunction. In contrast, DPFE had no effect on reversing apomorphine-induced disruptions of prepulse inhibition of the acoustic startle reflex. These mGlu5 PAMs also increased monoamine levels in the prefrontal cortex, enhanced performance in a hippocampal-mediated memory task, and elicited changes in electroencephalogram dynamics commensurate with procognitive effects. Collectively, these data support and extend the role for the development of novel mGlu5 PAMs for the treatment of psychosis and cognitive deficits observed in individuals with schizophrenia. PMID:23965381

Gregory, K J; Herman, E J; Ramsey, A J; Hammond, A S; Byun, N E; Stauffer, S R; Manka, J T; Jadhav, S; Bridges, T M; Weaver, C D; Niswender, C M; Steckler, T; Drinkenburg, W H; Ahnaou, A; Lavreysen, H; Macdonald, G J; Bartolomé, J M; Mackie, C; Hrupka, B J; Caron, M G; Daigle, T L; Lindsley, C W; Conn, P J; Jones, C K

2013-11-01

154

21 CFR 201.200 - Disclosure of drug efficacy study evaluations in labeling and advertising.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Disclosure of drug efficacy study evaluations in labeling and advertising... Labeling Claims for Drugs in Drug Efficacy Study § 201.200 Disclosure of drug efficacy study evaluations in labeling and advertising....

2010-04-01

155

21 CFR 201.200 - Disclosure of drug efficacy study evaluations in labeling and advertising.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Disclosure of drug efficacy study evaluations in labeling and advertising... Labeling Claims for Drugs in Drug Efficacy Study § 201.200 Disclosure of drug efficacy study evaluations in labeling and advertising....

2011-04-01

156

The discovery of rivaroxaban: translating preclinical assessments into clinical practice  

PubMed Central

Direct oral anticoagulants that target a single coagulation factor (such as factor Xa or thrombin) have been developed in recent years in an attempt to address some of the limitations of traditional anticoagulants. Rivaroxaban is an oral, direct factor Xa inhibitor that inhibits free and clot-bound factor Xa and factor Xa in the prothrombinase complex. Preclinical studies demonstrated a potent anticoagulant effect of rivaroxaban in plasma as well as the ability of this agent to prevent and treat venous and arterial thrombosis in animal models. These studies led to an extensive phase I clinical development program that investigated the pharmacological properties of rivaroxaban in humans. In these studies, rivaroxaban was shown to exhibit predictable pharmacokinetics and pharmacodynamics and to have no clinically relevant interactions with many commonly prescribed co-medications. The pharmacodynamic effects of rivaroxaban (for example, inhibition of factor Xa and prolongation of prothrombin time) were closely correlated with rivaroxaban concentrations in plasma. The encouraging findings from preclinical and early clinical studies were expanded upon in large, randomized phase III studies, which demonstrated the clinical efficacy and safety of rivaroxaban in a broad spectrum of patients. This article provides an overview of the discovery and development of rivaroxaban, describing the pharmacodynamic profile established in preclinical studies and the optimal translation to clinical studies in healthy subjects and patient populations. PMID:24324436

Kubitza, Dagmar; Perzborn, Elisabeth; Berkowitz, Scott D.

2013-01-01

157

Evaluation of dietetic product innovations: the relative role of preclinical and clinical studies.  

PubMed

A variety of systems are used to establish efficacy of food ingredients. Immortal human cell lines have the advantage of rapid throughput and often have the ability to point to mechanisms of action. Transgenic and natural variants of animals (usually rats and mice) have proven to be extremely useful in elucidating effects in vivo, although extrapolation of results to humans has risks. Animal models are also useful in establishing safety and toxic levels of ingredients. Human trials have the most relevance to society. Types of evidence for efficacy rise from improved status level in subjects as a result of eating food (long-chain polyunsaturated fatty acid, levels in erythrocytes), change in surrogate markers as a result of eating food (plasma cholesterol or glutathione peroxidase activity), change in a physiological outcome (such as visual evoked potential acuity or heart rate variability) through to the highest level of evidence, a change in a clinical outcome (improved global development, reduction in infections) established in randomized controlled trials. Ultimately, there is a need for tests of pragmatic interventions that can easily be incorporated into usual dietary practices of the culture in which it is tested. PMID:20664222

Makrides, Maria; Gibson, Robert A

2010-01-01

158

Meaningful prevention of breast cancer metastasis: candidate therapeutics, preclinical validation, and clinical trial concerns.  

PubMed

The development of drugs to treat breast and other cancers proceeds through phase I dose finding, phase II efficacy, and phase III comparative studies in the metastatic setting, only then asking if metastasis can be prevented in adjuvant trials. Compounds without overt cytotoxic activity, such as those developed to inhibit metastatic colonization, will likely fail to shrink established lesions in the metastatic setting and never be tested in a metastasis prevention scenario where they were preclinically validated. We and others have proposed phase II primary and secondary metastasis prevention studies to address this need. Herein, we have asked whether preclinical metastasis prevention data agrees with the positive adjuvant setting trials. The data are limited but complimentary. We also review fundamental pathways involved in metastasis, including Src, integrins, focal adhesion kinase (FAK), and fibrosis, for their clinical progress to date and potential for metastasis prevention. Issues of inadequate preclinical validation and clinical toxicity profiles are discussed. PMID:25412774

Zimmer, Alexandra S; Steeg, Patricia S

2015-01-01

159

Efficacy of citalopram in anorexia nervosa: a pilot study  

Microsoft Academic Search

Introduction: Anorexia nervosa (AN) still lacks a defined treatment. Since fluoxetine proved effective in weight-restored anorexics, this pilot study evaluates the efficacy of another SSRI, citalopram, in restricting-type AN. Experimental procedures: Fifty-two female anorectic outpatients were randomized in the citalopram (n=26) and waiting list (n=26) as a control group. Efficacy was assessed using Eating Disorder Inventory-2, Eating Disorder Inventory-Symptom Checklist,

Secondo Fassino; Paolo Leombruni; Giovanni Abbate Daga; Annalisa Brustolin; Giuseppe Migliaretti; Franco Cavallo; Giovanni G Rovera

2002-01-01

160

The contribution of regional gray/white matter volume in preclinical depression assessed by the Automatic Thoughts Questionnaire: a voxel-based morphometry study.  

PubMed

Negative automatic thought is a characteristic of depression that contributes toward the risk for episodes of depression. Evidence suggests that gray and white matter abnormalities are linked with depression, but little is known about the association between the negative cognitive experience and brain structure in preclinical depression. We examined the correlation between negative thought and gray (GMV)/white matter volume (WMV) in healthy individuals with preclinical depression. The participants were 309 university students with preclinical depression, as measured by their Automatic Thoughts Questionnaire (ATQ) scores. We collected brain MRIs and used voxel-based morphometry to analyze the correlation of regional GMV/WMV with the ATQ scores. The voxel-based morphometry results showed that the GMV of the right parahippocampal gyrus and fusiform gyrus and the WMV of the right superior temporal pole increased with the severity of depression. Furthermore, the corpus callosum volume decreased with the ATQ scores. This study implied that GMV increase and corpus callosum volume reduction may be associated with negative thought in nonclinical individuals, even at a preclinical depressed level. PMID:24999908

Cun, Lingli; Wang, Yanqiu; Zhang, Songyan; Wei, Dongtao; Qiu, Jiang

2014-09-10

161

Preclinical Studies of the Chinese Herbal Medicine formulation PHY906 as a Potential Adjunct to Radiation Therapy  

PubMed Central

Purpose/Objectives Abdominal and pelvic radiotherapy is limited by the radiosensitivity of the small and large intestine. PHY906, a state-of-the-art adaptation of a traditional Chinese medicine, decreased intestinal injury from chemotherapy in preclinical studies and is in clinical trials with chemotherapy. This project assessed whether PHY906 would also reduce intestinal injury from whole-abdomen irradiation in mice. Materials/Methods BALB/c mice received whole-abdomen irradiation (2 Gy/day) ± PHY906 by oral gavage twice daily for 4 days. Intestinal injury was assayed by physiological observations and histological studies. Effects of PHY906 on tumor radiation response were assayed in tumor growth studies. Results PHY906 decreased the toxicity of fractionated abdominal irradiation. Radiation alone produced marked blunting and loss of villi, crypt loss, crypt hyperplasia and irregular crypt morphology, which were reduced by PHY906. The radiation-induced reduction in viable crypt counts was also mitigated by PHY906. PHY906 did not alter radiation-induced weight loss, but resulted in more rapid recovery. PHY906 did not alter growth, local invasion or metastatic spread of EMT6 mouse mammary tumors or protect tumors from growth delays produced by single-dose and fractionated irradiation. Conclusion In this mouse model system, PHY906 decreased the toxicity of abdominal irradiation, without protecting tumors, thereby increasing the therapeutic ratio. PMID:22856538

Rockwell, Sara; Grove, Tina A.; Liu, Yanfeng; Cheng, Yung-Chi; Higgins, Susan A; Booth, Carmen J

2013-01-01

162

Erlotinib exhibits antineoplastic off-target effects in AML and MDS: a preclinical study.  

PubMed

Erlotinib, an inhibitor of the epidermal growth factor receptor (EGFR), induces differentiation, cell-cycle arrest, and apoptosis of EGFR-negative myeloblasts of patients with myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), as well as in EGFR-negative cell lines representing these diseases (P39, KG-1, and HL 60). This off-target effect can be explained by inhibitory effects on JAK2. Apoptosis induction coupled to mitochondrial membrane permeabilization occurred independently from phenotypic differentiation. In apoptosis-sensitive AML cells, erlotinib caused a rapid (within less than 1 hour) nucleocytoplasmic translocation of nucleophosmin-1 (NPM-1) and p14(ARF). Apoptosis-insensitive myeloblasts failed to manifest this translocation yet became sensitive to apoptosis induction by erlotinib when NPM-1 was depleted by RNA interference. Moreover, erlotinib reduced the growth of xenografted human AML cells in vivo. Erlotinib also killed CD34(+) bone marrow blasts from MDS and AML patients while sparing normal CD34(+) progenitors. This ex vivo therapeutic effect was once more associated with the nucleocytoplasmic translocation of NPM-1 and p14(ARF). One patient afflicted with both MDS and non-small cell lung cancer manifested hematologic improvement in response to erlotinib. In summary, we here provide novel evidence in vitro, ex vivo, and in vivo for the potential therapeutic efficacy of erlotinib in the treatment of high-risk MDS and AML. PMID:17925489

Boehrer, Simone; Adès, Lionel; Braun, Thorsten; Galluzzi, Lorenzo; Grosjean, Jennifer; Fabre, Claire; Le Roux, Génèviève; Gardin, Claude; Martin, Antoine; de Botton, Stéphane; Fenaux, Pierre; Kroemer, Guido

2008-02-15

163

Kidney Injury Molecule-1 Outperforms Traditional Biomarkers of Kidney Injury in Multi-site Preclinical Biomarker Qualification Studies  

PubMed Central

Kidney toxicity accounts for a significant percentage of morbidity and drug candidate failure. Serum creatinine (SCr) and blood urea nitrogen (BUN) have been used to monitor kidney dysfunction for over a century but these markers are insensitive and non-specific. In multi-site preclinical rat toxicology studies the diagnostic performance of urinary kidney injury molecule-1 (Kim-1) was compared to traditional biomarkers as predictors of kidney tubular histopathologic changes, currently considered the “gold standard” of nephrotoxicity. In multiple models of kidney injury, urinary Kim-1 significantly outperformed SCr and BUN. The area under the receiver operating characteristic curve for Kim-1 was between 0.91 and 0.99 as compared to 0.79 to 0.9 for BUN and 0.73 to 0.85 for SCr. Thus urinary Kim-1 is the first injury biomarker of kidney toxicity qualified by the FDA and EMEA and is expected to significantly improve kidney safety monitoring. PMID:20458318

Vaidya, Vishal S.; Ozer, Josef S.; Frank, Dieterle; Collings, Fitz B.; Ramirez, Victoria; Troth, Sean; Muniappa, Nagaraja; Thudium, Douglas; Gerhold, David; Holder, Daniel J.; Bobadilla, Norma A.; Marrer, Estelle; Perentes, Elias; Cordier, André; Vonderscher, Jacky; Maurer, Gérard; Goering, Peter L.; Sistare, Frank D.; Bonventre, Joseph V.

2010-01-01

164

A review of treatment planning for precision image-guided photon beam pre-clinical animal radiation studies.  

PubMed

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. PMID:24629309

Verhaegen, Frank; van Hoof, Stefan; Granton, Patrick V; Trani, Daniela

2014-12-01

165

Self-Efficacy and Strategies to Influence the Study Environment  

ERIC Educational Resources Information Center

This study investigates the relationship between student influence and academic self-efficacy in a sample of 275 students in two Master's programmes in Engineering. Students in only one of the programmes studied according to problem-based learning (PBL). Results indicate that students choosing strategies to influence course content or structure,…

Jungert, Tomas; Rosander, Michael

2010-01-01

166

Identification of new treatments for epilepsy: issues in preclinical methodology  

PubMed Central

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

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

167

Preclinical Studies of the Potent and Selective Nicotinic ?4?2 Receptor Ligand VMY-2-95.  

PubMed

The discovery and development of small molecules that antagonize neuronal nicotinic acetylcholine receptors may provide new ligands for evaluation in models of depression or addiction. We discovered a small molecule, VMY-2-95, a nAChR ligand with picomolar affinity and high selectivity for ?4?2 receptors. In this study, we investigated its preclinical profile in regards to solubility, lipophilicity, metabolic stability, intestinal permeability, bioavailability, and drug delivery to the rat brain. Metabolic stability of VMY-2-95·2HCl was monitored on human liver microsomes, and specific activity of VMY-2-95·2HCl on substrate metabolism by CYP1A2, 2C9, 2C19, 2D6, and 3A4 was tested in a high-throughput manner. The intestinal transport of VMY-2-95·2HCl was studied through Caco-2 cell monolayer permeability. VMY-2-95·2HCl was soluble in water and chemically stable, and the apparent partition coefficient was 0.682. VMY-2-95·2HCl showed significant inhibition of CYP2C9 and 2C19, but weak or no effect on 1A2, 2D6, and 3A4. The Caco-2 cell model studies revealed that VMY-2-95·2HCl was highly permeable with efflux ratio of 1.11. VMY-2-95·2HCl achieved a maximum serum concentration of 0.56 mg/mL at 0.9 h and was orally available with a half-life of ?9 h. Furthermore, VMY-2-95·2HCl was detected in the rat brain after 3 mg/kg oral administration and achieved a maximal brain tissue concentration of 2.3 ?g/g within 60 min. Overall, the results demonstrate that VMY-2-95·2HCl has good drug like properties and can penetrate the blood-brain barrier with oral administration. PMID:25533629

Kong, Hyesik; Song, Jun-Ke; Yenugonda, Venkata Mahidhar; Zhang, Li; Shuo, Tian; Cheema, Amrita K; Kong, Yali; Du, Guan-Hua; Brown, Milton L

2015-02-01

168

Efficacy and Tolerability of Almotriptan in Postmarketing Surveillance Studies  

Microsoft Academic Search

While randomized, double-blind, placebo-controlled trials are considered the gold standard of clinical evidence, they are limited by patient numbers, duration of patient exposure, and restricted patient populations. Data from controlled trials may not be generalizable to all individuals likely to take the drug under investigation. Postmarketing surveillance studies are designed to measure efficacy and safety in larger and more diverse

Julio Pascual

2005-01-01

169

Original article In vivo studies on lysosubtilin. 3. Efficacy for  

E-print Network

Original article In vivo studies on lysosubtilin. 3. Efficacy for treatment of mastitis (mastitis, superficial lesions of the udder and teats) in cows. Prior to determination of optimal. The examinations revealed a high incidence of poly- microbial infections (26.9 and 84.9 % for mastitis

Boyer, Edmond

170

Preclinical Studies of YK-4-272, an Inhibitor of Class II Histone Deacetylases by Disruption of Nucleocytoplasmic Shuttling  

PubMed Central

Purpose The HDAC shuttling inhibitor, YK-4-272 functions by restricting nuclear shuttling of Class II HDACs. Pre-clinical investigations of YK-4-272 bioavailability, pharmacokinetics, in vivo toxicity and tumor growth inhibition were performed to determine its potential as an HDAC shuttling disruptor for use in clinical applications. Methods The solubility, lipophilicity, in vitro metabolic stability, in vitro intestinal permeability, and in vivo pharmacokinetics of YK-4-272 were determined by HPLC methods. The anti-tumor activity of YK-4-272 was determined by monitoring athymic Balb/c nude mice bearing PC-3 xenografts. Results Oral bioavailability of YK-4-272 is supported by its solubility (0.537 mg/mL) and apparent partition coefficient of 2.0. The compound was chemically and metabolically stable and not a substrate for CYP450. In Caco-2 cell transport studies, YK-4-272 was highly permeable. The time-concentration profile of YK- 4-272 in plasma resulted in a Cmax of 2.47 µg/mL at 0.25 h with a AUC of 3.304 µg×h/mL. Treatment of PC-3 tumor xenografts with YK-4-272 showed significant growth delay. Conclusions YK-4-272 is stable and bio-available following oral administration. Growth inhibition of cancer cells and tumors was observed. These studies support advancing YK-4-272 for further evaluation as a novel HDAC shuttling inhibitor for use in cancer treatment. PMID:22836184

Kong, Hye-Sik; Tian, Shuo; Kong, Yali; Du, Guanhua; Zhang, Li; Jung, Mira; Dritschilo, Anatoly

2013-01-01

171

Virtual reality, augmented reality, and robotics applied to digestive operative procedures: from in vivo animal preclinical studies to clinical use  

NASA Astrophysics Data System (ADS)

Technological innovations of the 20 th century provided medicine and surgery with new tools, among which virtual reality and robotics belong to the most revolutionary ones. Our work aims at setting up new techniques for detection, 3D delineation and 4D time follow-up of small abdominal lesions from standard mecial images (CT scsan, MRI). It also aims at developing innovative systems making tumor resection or treatment easier with the use of augmented reality and robotized systems, increasing gesture precision. It also permits a realtime great distance connection between practitioners so they can share a same 3D reconstructed patient and interact on a same patient, virtually before the intervention and for real during the surgical procedure thanks to a telesurgical robot. In preclinical studies, our first results obtained from a micro-CT scanner show that these technologies provide an efficient and precise 3D modeling of anatomical and pathological structures of rats and mice. In clinical studies, our first results show the possibility to improve the therapeutic choice thanks to a better detection and and representation of the patient before performing the surgical gesture. They also show the efficiency of augmented reality that provides virtual transparency of the patient in real time during the operative procedure. In the near future, through the exploitation of these systems, surgeons will program and check on the virtual patient clone an optimal procedure without errors, which will be replayed on the real patient by the robot under surgeon control. This medical dream is today about to become reality.

Soler, Luc; Marescaux, Jacques

2006-04-01

172

Investigating the efficacy of practical skill teaching: a pilot-study comparing three educational methods.  

PubMed

Effective education of practical skills can alter clinician behaviour, positively influence patient outcomes, and reduce the risk of patient harm. This study compares the efficacy of two innovative practical skill teaching methods, against a traditional teaching method. Year three pre-clinical physiotherapy students consented to participate in a randomised controlled trial, with concealed allocation and blinded participants and outcome assessment. Each of the three randomly allocated groups were exposed to a different practical skills teaching method (traditional, pre-recorded video tutorial or student self-video) for two specific practical skills during the semester. Clinical performance was assessed using an objective structured clinical examination (OSCE). The students were also administered a questionnaire to gain the participants level of satisfaction with the teaching method, and their perceptions of the teaching methods educational value. There were no significant differences in clinical performance between the three practical skill teaching methods as measured in the OSCE, or for student ratings of satisfaction. A significant difference existed between the methods for the student ratings of perceived educational value, with the teaching approaches of pre-recorded video tutorial and student self-video being rated higher than 'traditional' live tutoring. Alternative teaching methods to traditional live tutoring can produce equivalent learning outcomes when applied to the practical skill development of undergraduate health professional students. The use of alternative practical skill teaching methods may allow for greater flexibility for both staff and infrastructure resource allocation. PMID:22354336

Maloney, Stephen; Storr, Michael; Paynter, Sophie; Morgan, Prue; Ilic, Dragan

2013-03-01

173

Preclinical studies of the proteasome inhibitor bortezomib in malignant pleural mesothelioma.  

PubMed

Malignant pleural mesothelioma (MPM) is a highly lethal neoplasm that is resistant to chemotherapy. Bortezomib is an FDA-approved proteasome inhibitor that is currently under clinical investigation in multiple neoplasms but has not been studied extensively in MPM. In this report, we determine the biological and molecular response of cultured MPM cells to bortezomib alone and in combination with cisplatin or pemetrexed. We used four MPM cell lines (MS589, H28, H2052, JMN), a normal mesothelial cell line (HM3), and a lung cancer cell line (H23) in survival studies utilizing bortezomib, cisplatin, and pemetrexed alone and in combination by administering concurrently or by varying the order of administration. We determined the effect of bortezomib on the cell cycle, apoptosis, and on the expression of cell cycle proteins p21/WAF1 and p27/KIP1 and on apoptosis-related proteins IAP-1, IAP-2, survivin, and XIAP. Bortezomib was highly cytotoxic to MPM cells and induced both G(2)/M and G(1)/S cell cycle arrest. Apoptosis increased in a concentration- and time-dependent manner in 3 of 4 MPM cell lines. Bortezomib stabilized or increased protein levels of p21/WAF1 and IAP-1 and to a lesser degree p27/KIP1, IAP-2, XIAP, and survivin. In combination studies with cisplatin, bortezomib was generally synergistic at high concentrations and antagonistic at low concentrations. Bortezomib increased the cytotoxicity of cisplatin and pemetrexed in a concentration-dependent manner when administered prior to either. Bortezomib may improve outcome in MPM patients alone or in combination with standard chemotherapy but the order of administration is likely to be important. This study justifies further evaluation of bortezomib in MPM. PMID:17522864

Gordon, Gavin J; Mani, Madhubalan; Maulik, Gautam; Mukhopadhyay, Lipi; Yeap, Beow Y; Kindler, Hedy L; Salgia, Ravi; Sugarbaker, David J; Bueno, Raphael

2008-04-01

174

Wound healing activity of NOE-aspirin: A pre-clinical study  

Microsoft Academic Search

Aspirin, one of the oldest non-steroidal anti-inflammatory drugs, impedes tissue repair by virtue of retarding inflammation. The present study was undertaken to find out if linking of nitrooxyethyl ester to aspirin reverses its healing-depressant propensity. Nitrooxyethyl ester of aspirin (NOE-Asp) was synthesized in our laboratory through well-established synthetic pathway, starting from aspirin through esterification with ethylene glycol and nitration with

Mandeep Kaushal; N. Gopalan Kutty; C. Mallikarjuna Rao

2007-01-01

175

AAV-Mediated Gene Therapy for Choroideremia: Preclinical Studies in Personalized Models  

PubMed Central

Choroideremia (CHM) is an X- linked retinal degeneration that is symptomatic in the 1st or 2nd decade of life causing nyctalopia and loss of peripheral vision. The disease progresses through mid-life, when most patients become blind. CHM is a favorable target for gene augmentation therapy, as the disease is due to loss of function of a protein necessary for retinal cell health, Rab Escort Protein 1 (REP1).The CHM cDNA can be packaged in recombinant adeno-associated virus (rAAV), which has an established track record in human gene therapy studies, and, in addition, there are sensitive and quantitative assays to document REP1 activity. An animal model that accurately reflects the human condition is not available. In this study, we tested the ability to restore REP1 function in personalized in vitro models of CHM: lymphoblasts and induced pluripotent stems cells (iPSCs) from human patients. The initial step of evaluating safety of the treatment was carried out by evaluating for acute retinal histopathologic effects in normal-sighted mice and no obvious toxicity was identified. Delivery of the CHM cDNA to affected cells restores REP1 enzymatic activity and also restores proper protein trafficking. The gene transfer is efficient and the preliminary safety data are encouraging. These studies pave the way for a human clinical trial of gene therapy for CHM. PMID:23667438

Vasireddy, Vidyullatha; Kohnke, Monika; Black, Aaron D.; Alexandrov, Krill; Zhou, Shangzhen; Maguire, Albert M.; Chung, Daniel C.; Mac, Helen; Sullivan, Lisa; Gadue, Paul; Bennicelli, Jeannette L.; French, Deborah L.; Bennett, Jean

2013-01-01

176

Revising the high-density lipoprotein targeting strategies - insights from human and preclinical studies.  

PubMed

In recent years, the high-density lipoprotein (HDL) hypothesis has been challenged. Several completed randomized clinical trials continue to fall short in demonstrating HDL, or at least HDL-cholesterol (HDL-C) levels, as being a consistent target in the prevention of cardiovascular diseases. However, population studies and findings in lipid modifying trials continue to strongly support HDL-C as a superb risk predictor. It is increasingly evident that the complexity of HDL metabolism confounds the use of HDL-C concentration as a unified target. However, important insights continue to emerge from the post hoc analyses of recently completed (i) fibrate-based FIELD and ACCORD trials, including the unexpected beneficial effect of fibrates in microvascular diseases, (ii) the niacin-based AIM-HIGH and HPS2-THRIVE studies, (iii) recombinant HDL-based as well as (iv) the completed CETP inhibitor-based trials. These together with on-going mechanistic studies on novel pathways, which include the unique roles of microRNAs, post-translational remodeling of HDL and novel pathways related to HDL modulators will provide valuable insights to guide how best to refocus and redesign the conceptual framework for selecting HDL-based targets. PMID:25115413

Nesan, Dinushan; Ng, Dominic S

2014-12-01

177

Hydration with Saline Decreases Toxicity of Mice Injected With Calcitriol in Preclinical Studies  

PubMed Central

The effectiveness of saline injection in reducing the toxicity profile of calcitriol when coadministered in mice was evaluated. Mortality was used as an end point to study the toxic effects of calcitriol; the relative risk of mortality in mice injected with saline was evaluated from our previously published animal experiments. We discovered that coadministration with 0.25 mL normal saline solution injected intraperitoneally is associated with a lower mortality rate than calcitriol given alone. The estimated relative risk of mortality was 0.0789 (95% confidence interval, 0.0051–1.22; z = 1.82; P = 0.070) when saline is administered with calcitriol compared to calcitriol alone. There was a reduction in serum calcium levels in mice that received saline (11.4 ± 0.15 mg/dL) compared to mice that did not receive saline (12.42 ± 1.61 mg/dL). Hydration with saline seems to reduce mortality and toxicity in mice receiving calcitriol. Given the decrease in mortality rates, intraperitoneal injections of saline should be considered in studies involving mice receiving injections of calcitriol. PMID:24266410

Azari, Amir A; Kanavi, Mozhgan R.; Darjatmoko, Soesiawati R.; Lee, Vivian; Kim, KyungMann; Potter, Heather D.; Albert, Daniel M.

2014-01-01

178

Novel sugar esters proniosomes for transdermal delivery of vinpocetine: preclinical and clinical studies.  

PubMed

Vinpocetine (Vin) existing oral formulations suffer poor bioavailability (?7%) since Vin undergoes a marked first-pass effect (?75%) and its absorption is dissolution rate-limited. In this study, a novel sustained release proniosomal system was designed using sugar esters (SEs) as non-ionic surfactants in which proniosomes were converted to niosomes upon skin water hydration following topical application under occlusive conditions. Different in vitro aspects (encapsulation efficiency, vesicle size and shape, effect of occlusion, in vitro release, skin permeation and stability) were studied leading to an optimized formula that was assessed clinically for transdermal pharmacokinetics and skin irritation. All formulae exhibited high entrapment efficiencies, regardless of the surfactant HLB. Vesicle size analysis showed that all vesicles were in the range from 0.63 ?m to 2.52 ?m which favored efficient transdermal delivery. The extent of drug permeation through the skin from the optimized formula--containing laurate SE with shorter fatty acid chain length and high HLB--was quite high (91%) after 48 h under occlusive conditions. The extent of absorption of Vin from proniosomes was larger when compared to the oral tablet with a relative bioavailability (F(rel)) of 206%. Histopathological evaluation revealed only moderate skin irritation when using SEs compared to skin inflammation when using Tween 80. Sugar esters proniosomes may be a promising carrier for vinpocetine, especially due to their simple scaling up and their ability to control drug release. PMID:21056658

El-Laithy, Hanan M; Shoukry, Omar; Mahran, Laila G

2011-01-01

179

Transoral endoscopic thyroidectomy via the tri-vestibular routes: results of a preclinical cadaver feasibility study.  

PubMed

The concept of natural orifice transluminal endoscopic surgery (NOTES) is an emerging experimental alternative to conventional surgery that eliminates skin incisions using an endoscope passed through a natural orifice (e.g., mouth, urethra, or anus). This study was designed to evaluate the feasibility and safety of thyroid resection via an entirely transoral tri-vestibular route using endoscopy, and to introduce NOTES to the head and neck area of medicine. We performed ten complete endoscopic thyroid lobectomies with central lymph node dissection via a tri-vestibular approach in fresh-frozen cadavers. A 5-mm endoscope with a deflectable tip was used to visualize the surgical field. Three cannulas were inserted through the midline and bilateral incision sites in the vestibule to position the instruments and endoscope. We refined and described the surgical technique in each step using video clips. We identified and preserved neighboring critical structures during surgery. We also confirmed that there were no obvious remnant thyroid tissues and no injury to the neighboring structures after exploration. The transoral tri-vestibular approach seems to provide a good view and surgical field for endoscopic thyroidectomy. However, the transoral approach for thyroidectomy remains experimental, and the detailed surgical technique should be refined via further clinical studies. PMID:24496566

Park, Jun-Ook; Kim, Choung Soo; Song, Jee-Nam; Kim, Ju-Eun; Nam, Inn-Chul; Lee, So-Yoon; Chun, Byung-Joon; Cho, Jung-Hae; Joo, Young-Hoon; Cho, Kwang-Jae; Park, Young Hak; Kim, Min-Sik; Sun, Dong-Il

2014-12-01

180

A Cre-conditional MYCN-driven neuroblastoma mouse model as an improved tool for preclinical studies.  

PubMed

Neuroblastoma, a childhood cancer that originates from neural crest-derived cells, is the most common deadly solid tumor of infancy. Amplification of the MYCN oncogene, which occurs in approximately 20-25% of human neuroblastomas, is the most prominent genetic marker of high-stage disease. The availability of valid preclinical in vivo models is a prerequisite to develop novel targeted therapies. We here report on the generation of transgenic mice with Cre-conditional induction of MYCN in dopamine ?-hydroxylase-expressing cells, termed LSL-MYCN;Dbh-iCre. These mice develop neuroblastic tumors with an incidence of >75%, regardless of strain background. Molecular profiling of tumors revealed upregulation of the MYCN-dependent miR-17-92 cluster as well as expression of neuroblastoma marker genes, including tyrosine hydroxylase and the neural cell adhesion molecule 1. Gene set enrichment analyses demonstrated significant correlation with MYC-associated expression patterns. Array comparative genome hybridization showed that chromosomal aberrations in LSL-MYCN;Dbh-iCre tumors were syntenic to those observed in human neuroblastomas. Treatment of a cell line established from a tumor derived from a LSL-MYCN;Dbh-iCre mouse with JQ1 or MLN8237 reduced cell viability and demonstrated oncogene addiction to MYCN. Here we report establishment of the first Cre-conditional human MYCN-driven mouse model for neuroblastoma that closely recapitulates the human disease with respect to tumor localization, histology, marker expression and genomic make up. This mouse model is a valuable tool for further functional studies and to assess the effect of targeted therapies.Oncogene advance online publication, 1 September 2014; doi:10.1038/onc.2014.269. PMID:25174395

Althoff, K; Beckers, A; Bell, E; Nortmeyer, M; Thor, T; Sprüssel, A; Lindner, S; De Preter, K; Florin, A; Heukamp, L C; Klein-Hitpass, L; Astrahantseff, K; Kumps, C; Speleman, F; Eggert, A; Westermann, F; Schramm, A; Schulte, J H

2014-09-01

181

The Usefulness of Systematic Reviews of Animal Experiments for the Design of Preclinical and Clinical Studies  

PubMed Central

The question of how animal studies should be designed, conducted, and analyzed remains underexposed in societal debates on animal experimentation. This is not only a scientific but also a moral question. After all, if animal experiments are not appropriately designed, conducted, and analyzed, the results produced are unlikely to be reliable and the animals have in effect been wasted. In this article, we focus on one particular method to address this moral question, namely systematic reviews of previously performed animal experiments. We discuss how the design, conduct, and analysis of future (animal and human) experiments may be optimized through such systematic reviews. In particular, we illustrate how these reviews can help improve the methodological quality of animal experiments, make the choice of an animal model and the translation of animal data to the clinic more evidence-based, and implement the 3Rs. Moreover, we discuss which measures are being taken and which need to be taken in the future to ensure that systematic reviews will actually contribute to optimizing experimental design and thereby to meeting a necessary condition for making the use of animals in these experiments justified. PMID:25541545

de Vries, Rob B. M.; Wever, Kimberley E.; Avey, Marc T.; Stephens, Martin L.; Sena, Emily S.; Leenaars, Marlies

2014-01-01

182

166Ho-microsphere liver radiotherapy: a preclinical SPECT dosimetry study in the pig.  

PubMed

Liver metastases cause the majority of deaths from colorectal cancer and response to chemotherapy is poor. Intrahepatic arterial 90Y-microspheres may induce tumour regression but the beta-radiation dose is variable and cannot be determined in patients. The 81 keV gamma emission of holmium-166 (166Ho) was used to determine, by single photon emission computed tomographic (SPECT) imaging, the beta-radiation absorbed dose to normal liver in pigs following intrahepatic arterial administration of 166Ho-microspheres. The SPECT system was calibrated with anthropomorphic liver phantoms containing known activity concentrations of 166Ho-chloride. The relationship of SPECT counts to phantom activity concentration was linear with a correlation coefficient of r = 0.996. The SPECT pattern of liver distribution following successive administrations of tracer activities of 166Ho-microspheres was similar. The ratio of initial to total SPECT estimates of mean activity concentration in regions of interest, from which anatomically matched biopsy samples were later obtained and counted in an ionization chamber, showed good correlation (r = 0.924). Prospective SPECT dosimetry performed on a tracer activity of 166Ho-microspheres predicted the total administered activity required to deliver a prescribed radiation absorbed dose of 25 Gy to the liver within an error of +/- 8%. This study demonstrates the feasibility of prospective control of the absorbed radiation dose to the critical normal organ by SPECT dosimetry on a tracer dose of 166Ho-microspheres prior to administration of a therapy dose. PMID:7970432

Turner, J H; Claringbold, P G; Klemp, P F; Cameron, P J; Martindale, A A; Glancy, R J; Norman, P E; Hetherington, E L; Najdovski, L; Lambrecht, R M

1994-07-01

183

Preclinical studies on neurobehavioral and neuromuscular effects of cocaine hydrolase gene therapy in mice.  

PubMed

Cocaine hydrolase gene transfer of mutated human butyrylcholinesterase (BChE) is evolving as a promising therapy for cocaine addiction. BChE levels after gene transfer can be 1,500-fold above those in untreated mice, making this enzyme the second most abundant plasma protein. Because mutated BChE is approximately 70 % as efficient in hydrolyzing acetylcholine as wild-type enzyme, it is important to examine the impact on cholinergic function. Here, we focused on memory and cognition (Stone T-maze), basic neuromuscular function (treadmill endurance and grip strength), and coordination (Rotarod). BALB/c mice were given adeno-associated virus vector or helper-dependent adenoviral vector encoding mouse or human BChE optimized for cocaine. Age-matched controls received saline or luciferase vector. Despite high doses (up to 10(13) particles per mouse) and high transgene expression (1,000-fold above baseline), no deleterious effects of vector treatment were seen in neurobehavioral functions. The vector-treated mice performed as saline-treated and luciferase controls in maze studies and strength tests, and their Rotarod and treadmill performance decreased less with age. Thus, neither the viral vectors nor the large excess of BChE caused observable toxic effects on the motor and cognitive systems investigated. This outcome justifies further steps toward an eventual clinical trial of vector-based gene transfer for cocaine abuse. PMID:24085526

Murthy, Vishakantha; Gao, Yang; Geng, Liyi; LeBrasseur, Nathan; White, Thomas; Brimijoin, Stephen

2014-07-01

184

GABAergic contributions to alcohol responsivity during adolescence: insights from preclinical and clinical studies.  

PubMed

There is a considerable body of literature demonstrating that adolescence is a unique age period, which includes rapid and dramatic maturation of behavioral, cognitive, hormonal and neurobiological systems. Most notably, adolescence is also a period of unique responsiveness to alcohol effects, with both hyposensitivity and hypersensitivity observed to the various effects of alcohol. Multiple neurotransmitter systems are undergoing fine-tuning during this critical period of brain development, including those that contribute to the rewarding effects of drugs of abuse. The role of developmental maturation of the ?-amino-butyric acid (GABA) system, however, has received less attention in contributing to age-specific alcohol sensitivities. This review integrates GABA findings from human magnetic resonance spectroscopy studies as they may translate to understanding adolescent-specific responsiveness to alcohol effects. Better understanding of the vulnerability of the GABA system both during adolescent development, and in psychiatric conditions that include alcohol dependence, could point to a putative mechanism, boosting brain GABA, that may have increased effectiveness for treating alcohol use disorders. PMID:24631274

Silveri, Marisa M

2014-08-01

185

Development of an Adenovirus-Based Respiratory Syncytial Virus Vaccine: Preclinical Evaluation of Efficacy, Immunogenicity, and Enhanced Disease in a Cotton Rat Model  

PubMed Central

ABSTRACT The lack of a vaccine against respiratory syncytial virus (RSV) is a challenging and serious gap in preventive medicine. Herein, we characterize the immunogenicity of an adenovirus serotype 5-based RSV vaccine encoding the fusion (F) protein (Ad5.RSV-F) and the protection provided following immunization with Ad5.RSV-F and assess its potential for producing enhanced disease in a cotton rat (CR) model. Animals were immunized intranasally (i.n.) and/or intramuscularly (i.m.) and subsequently challenged with RSV/A/Tracy (i.n.) to assess protection. Robust immune responses were seen in CRs vaccinated with Ad5.RSV-F given i.m. or i.n., and these responses correlated with reduced replication of the virus in noses and lungs after challenge. Neutralizing antibody responses following immunization with a single dose of Ad5.RSV-F at 1 × 1011 viral particles (v.p.) elicited antibody titers 64- to 256-fold greater than those seen after natural infection. CRs boosted with Ad5.RSV-F i.n. 28 days after an i.m. dose also had significant increases in neutralizing antibody titers. Antibody affinity for different F-protein antigenic sites revealed substantial differences between antibodies elicited by Ad5.RSV-F and those seen after RSV infection; differences in antibody profiles were also seen between CRs given Ad5.RSV-F i.m. and CRs given Ad5.RSV-F i.n. Ad5.RSV-F priming did not result in enhanced disease following live-virus challenge, in contrast to the histopathology seen in CRs given the formalin-inactivated RSV/A/Burnett vaccine. IMPORTANCE Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory infection in infants and young children and a serious health threat in the immunocompromised and the elderly. Infection severity increased in children in an immunization trial, hampering the over 4-decade-long quest for a successful RSV vaccine. In this study, we show that a genetically engineered RSV-F-encoding adenoviral vector provides protective immunity against RSV challenge without enhanced lung disease in cotton rats (CRs). CRs were vaccinated under a number of different regimens, and the immunity induced by the recombinant adenoviral RSV vaccine administered by use of an intramuscular prime-intranasal boost regimen may provide the best protection for young infants and children at risk of RSV infection, since this population is naive to adenoviral preformed immunity. Overall, this report describes a potential RSV vaccine candidate that merits further evaluation in a phase I clinical study in humans. PMID:24574396

Kim, Eun; Okada, Kaori; Beeler, Judy A.; Crim, Roberta L.; Piedra, Pedro A.; Gilbert, Brian E.

2014-01-01

186

Photoacoustic spectroscopy in the monitoring of breast tumor development: a pre-clinical study  

NASA Astrophysics Data System (ADS)

Breast cancer is the most frequently diagnosed cancer type and its detection at an early stage can reduce the mortality rate substantially. With the aim to detect breast cancer early, by studying tumor progression in nude mice, a pulsed laser induced photoacoustic spectroscopy set up has been designed and developed. MCF-7 cells xenografts were developed using six to eight weeks old female nude mice and tumor tissues were extracted on different days (10th, 15th and 20th Day) post injection and the corresponding photoacoustic spectra were recorded at 281nm excitation. A total of 144 time domain spectra were recorded from 36 animals belonging to the three time points (10th, 15th and 20th day post injection) and converted into frequency domains by Fast Fourier Transform (FFT) tools of the MATLAB algorithms and analyzed. The frequency patterns of the tumor masses on 10th, 15th and 20th day of tumor development showed a gradual increase in intensity at certain frequencies, 5.93 x103 Hz, 15.9 x103 Hz, 29.69 x103 Hz and 32.5 x103 Hz in the FFT patterns indicating that these frequencies were more sensitive towards tumor development. Further analysis of the data yielded a clear variation in the spectral parameters with progression of the disease suggesting that the technique may be suitable for early detection of the disease. Thus, we expect that the developed setup may be useful in assessing the different phases of tumor development which may have clinical implications.

Priya, Mallika; Rao, Bola Sadashiva Satish; Ray, Satadru; Mahato, Krishna Kishore

2014-03-01

187

Confocal Raman microspectroscopy of stratum corneum: a pre-clinical validation study.  

PubMed

Skin moisturization is not only important for maintaining skin functional properties but also has great impact on the skin's aesthetic properties. The top layer of the skin, the stratum corneum (SC), plays a key role in protecting and preventing against external aggressions as well as in regulating water flux in and out. Confocal Raman microspectroscopy is the first commercially available technique that provides a non-invasive, in vivo method to determine depth profiles of water concentration in the skin, however, in this case it was applied in an in vitro setting. As the first phase of validating the usefulness of confocal Raman microspectroscopy, we used porcine skin as a surrogate for human skin. Water concentration profiles were obtained using confocal Raman microspectroscopy from isolated pigskin SC and compared with that using the Karl Fischer titration method. The two methods correlated very well with a regression coefficient of 1.07 as well as a correlation coefficient, R(2) = 0.989, which demonstrated the consistency and accuracy of confocal Raman microspectroscopy for water concentration determination. To evaluate the instrument's response to different skin care/cleansing products, a wide range of products were tested to compare their skin moisturization ability. Among those tested were a lotion, commercial soap bar, syndet bar, traditional non-emollient shower gel (water, Sodium Laureth Ether Sulfate (SLES), cocamidopropyl betaine system) and emollient containing shower gel (water, sunflower oil, SLES, cocamidopropyl betaine, glycerin, petrolatum). The results were consistent with what was expected. The water content on skin treated with (A) lotion was significantly higher than the non-treated control; (B) syndet bar-treated skin had a significantly higher water content than soap-based bar-treated sites; (C) non-emollient shower gel washed sites were more moisturized than soap-based bar-treated samples; and (D) emollient shower gel-treated skin was significantly more hydrated than non-emollient shower gel washed skin. The unique and direct quantitative water content information provided by confocal Raman microspectroscopy offers a whole new perspective for fundamental skin moisturization studies and will play an important role in evaluating moisturizing profiles and the hydration potential of products designed for personal care in the cosmetic industry. PMID:18377630

Wu, J; Polefka, T G

2008-02-01

188

Fiber optic fluorescence detection of low-level porphyrin concentrations in preclinical and clinical studies  

NASA Astrophysics Data System (ADS)

A significant clinical problem in the local treatment of cutaneous metastases of breast cancer (by any modality--surgery, radiation therapy or photodynainic therapy) is the fact that the disease almost always extends beyond the boundary of visible lesions in the form of microscopic deposits. These deposits may be distant from the site of visible disease but are often in close proximity to it and are manifested sooner or later by the development of recurrent lesions at the border of the treated area, thus the "marginal miss" in radiation therapy, the "rim recurrence" in photodynamic therapy, and the "incisional recurrence" following surgical excision. More intelligent use of these treatment modalities demands the ability to detect microscopic deposits of tumor cells using non-invasive methodology. In vivo fluorescence measurements have been made possible by the development of an extremely sensitive fiber optic in vivo fluorescence photometer. The instrument has been used to verify that fluorescence correlated with injected porphyrin levels in various tissues. The delivery of light to excite and detect background fluorescence as well as photosensitizer fluorescence in tissues has been accomplished using two HeNe lasers emitting at 632.8 nm and 612 nm delivered through a single quartz fiber optic. Chopping at different frequencies, contributions of fluorescence may be separated. Fluorescence is picked up via a 400 micron quartz fiber optic positioned appropriately near the target tissue. Validation of these levels was made by extraction of the drug from the tissues with resultant quantitation. Recently, an extensive study was undertaken to determine if fluorescence could be used for the detection of occult, clinically non-palpable metastases in the lymph node of rats. This unique model allowed for the detection of micrometastases in lymph nodes using very low injected doses of the photosensitizer Photofrin II. Data obtained revealed the ability to detect on the order of 50-100 cells using 0.25 mg/kg of sensitizer, a level 20 times lower than normally used for treatment of animal tumors. These results indicate that Photofrin II could be used for fluorescence detection of small metastatic tumors, while substantially reducing the major side effect of PDT; namely, prolonged photosensitivity. Results to be presented demonstrate the ability of this technique to detect microscopic deposits of malignant tumor cells in patients with metastatic breast cancer. These deposits were found in clinically negative areas of the chest wall.

Mang, Thomas S.; McGinnis, Carolyn; Khan, S.

1990-07-01

189

Efficacy of olanzapine in social anxiety disorder: a pilot study  

Microsoft Academic Search

Based on evidence suggesting anxiolytic properties of the atypical antipsychotic olanzapine, this study was conducted to evaluate whether olanzapine may be efficacious in treating social anxiety disorder (SAD). This study was an 8-week, double-blind, placebo-controlled evaluation of olanzapine as monotherapy in which 12 patients with the DSM-IV diagnosis of SAD were randomized to either olanzapine (n= 7) or placebo (n=

Stewart D. Barnett; Michelle L. Kramer; Charles D. Casat; Kathryn M. Connor; Jonathan R. T. Davidson

2002-01-01

190

Capecitabine: Preclinical Pharmacology Studies  

Microsoft Academic Search

Capecitabine (N4-pentyloxycarbonyl-5'-deoxy-5-fluorocytidine) is a novel fluoropyrimidine carbamate, which was designed to besequentially converted to 5-fluorouracil (5-FU) by three enzymes located inthe liver and in tumors; the final step is the conversion of5'-deoxy-5-fluorouridine (5'-DFUR) to 5-FU by thymidine phosphorylase (dThdPase) in tumors. In human cancer xenograft models, capecitabine given orally yielded substantially higher concentrations of 5-FU within tumors than in plasma

Hideo Ishitsuka

2000-01-01

191

Towards developing standard operating procedures for pre-clinical testing in the mdx mouse model of Duchenne muscular dystrophy  

PubMed Central

This review discusses various issues to consider when developing standard operating procedures for pre-clinical studies in the mdx mouse model of Duchenne muscular dystrophy (DMD). The review describes and evaluates a wide range of techniques used to measure parameters of muscle pathology in mdx mice and identifies some basic techniques that might comprise standardised approaches for evaluation. While the central aim is to provide a basis for the development of standardised procedures to evaluate efficacy of a drug or a therapeutic strategy, a further aim is to gain insight into pathophysiological mechanisms in order to identify other therapeutic targets. The desired outcome is to enable easier and more rigorous comparison of pre-clinical data from different laboratories around the world, in order to accelerate identification of the best pre-clinical therapies in the mdx mouse that will fast-track translation into effective clinical treatments for DMD. PMID:18499465

Grounds, Miranda D.; Radley, Hannah G.; Lynch, Gordon S.; Nagaraju, Kanneboyina; De Luca, Annamaria

2008-01-01

192

Does interprofessional simulation increase self-efficacy: a comparative study  

PubMed Central

Objectives In this work, we have compared uniprofessional and interprofessional versions of a simulation education intervention, in an attempt to understand more about whether it improves trainees’ self-efficacy. Background Interprofessionalism has been climbing the healthcare agenda for over 50?years. Simulation education attempts to create an environment for healthcare professionals to learn, without potential safety risks for patients. Integrating simulation and interprofessional education can provide benefits to individual learners. Setting The intervention took place in a high-fidelity simulation facility located on the campus of a large urban hospital. The centre provides educational activities for an Academic Health Sciences Centre. Approximately 2500 staff are trained at the centre each year. Participants One hundred and fifteen nurses and midwives along with 156 doctors, all within the early years of their postgraduate experience participated. All were included on the basis of their ongoing postgraduate education. Methods Each course was a one-day simulation course incorporating five clinical and one communication scenarios. After each a facilitated debriefing took place. A mixed methods approach utilised precourse and postcourse questionnaires measuring self-efficacy in managing emergency situations, communication, teamwork and leadership. Results Thematic analysis of qualitative data showed improvements in communication/teamwork and leadership, for doctors and nurses undergoing simulation training. These findings were confirmed by statistical analysis showing that confidence ratings improved in nurses and doctors overall (p<0.001). Improved outcomes from baseline were observed for interprofessional versus uniprofessional trained nurses (n=115; p<0.001). Postcourse ratings for doctors showed that interprofessional training was significantly associated with better final outcomes for a communication/teamwork dimension (n=156; p<0.05). Conclusions This study provides evidence that simulation training enhances participants’ self-efficacy in clinical situations. It also leads to increases in their perceived abilities relating to communication/teamwork and leadership/management of clinical scenarios. Interprofessional training showed increased positive effects on self-efficacy for nurses and doctors. PMID:25586366

Watters, Colm; Reedy, Gabriel; Ross, Alastair; Morgan, Nicola J; Handslip, Rhodri; Jaye, Peter

2015-01-01

193

Premarket Safety and Efficacy Studies for ADHD Medications in Children  

PubMed Central

Background Attention-deficit hyperactivity disorder (ADHD) is a chronic condition and pharmacotherapy is the mainstay of treatment, with a variety of ADHD medications available to patients. However, it is unclear to what extent the long-term safety and efficacy of ADHD drugs have been evaluated prior to their market authorization. We aimed to quantify the number of participants studied and their length of exposure in ADHD drug trials prior to marketing. Methods We identified all ADHD medications approved by the Food and Drug Administration (FDA) and extracted data on clinical trials performed by the sponsor and used by the FDA to evaluate the drug’s clinical efficacy and safety. For each ADHD medication, we measured the total number of participants studied and the length of participant exposure and identified any FDA requests for post-marketing trials. Results A total of 32 clinical trials were conducted for the approval of 20 ADHD drugs. The median number of participants studied per drug was 75 (IQR 0, 419). Eleven drugs (55%) were approved after <100 participants were studied and 14 (70%) after <300 participants. The median trial length prior to approval was 4 weeks (IQR 2, 9), with 5 (38%) drugs approved after participants were studied <4 weeks and 10 (77%) after <6 months. Six drugs were approved with requests for specific additional post-marketing trials, of which 2 were performed. Conclusions Clinical trials conducted for the approval of many ADHD drugs have not been designed to assess rare adverse events or long-term safety and efficacy. While post-marketing studies can fill in some of the gaps, better assurance is needed that the proper trials are conducted either before or after a new medication is approved. PMID:25007171

Bourgeois, Florence T.; Kim, Jeong Min; Mandl, Kenneth D.

2014-01-01

194

The Structure of Children's Perceived Self-Efficacy: A Cross-National Study  

Microsoft Academic Search

The present study investigated the replicability of the factor structure of the Children's Perceived Self-Efficacy scales (CPSE; Bandura, 1990) in Italy, Hungary, and Poland. The findings of this cross-national study support the generalizability of the factor structure of children's social and academic efficacy. Perceived efficacy to resist peer pressure to engage transgressive conduct had a somewhat different factor structure for

Concetta Pastorelli; Gian Vittorio Caprara; Claudio Barbaranelli; Jarek Rola; Sandor Rozsa; Albert Bandura

2001-01-01

195

An Exploratory Study of Teacher Self-Efficacy Beliefs and Professional Learning Community  

ERIC Educational Resources Information Center

The exploratory study sought to examine the relationships between teachers' self-efficacy beliefs and professional learning community. Specifically, this study presents a quantitative analysis of the relationship between teachers' perceptions of self-efficacy and PLC implementation. The Teachers' Sense of Efficacy Scale (TSES) (long form)…

Romeo, Susan M.

2010-01-01

196

Magnesium is not consistently neuroprotective for perinatal hypoxia-ischemia in term-equivalent models in preclinical studies: a systematic review.  

PubMed

There is an important unmet need to further improve the outcome of neonatal encephalopathy in term infants. Meta-analyses of large controlled trials now suggest that maternal magnesium sulfate (MgSO4) therapy is associated with a reduced risk of cerebral palsy and gross motor dysfunction after premature birth, but that it has no effect on death or disability. Because of this inconsistency, it remains controversial whether MgSO4 is clinically neuroprotective and, thus, it is unclear whether it would be appropriate to test MgSO4 for treatment of encephalopathy in term infants. We therefore systematically reviewed the preclinical evidence for neuroprotection with MgSO4 before or after hypoxic-ischemic encephalopathy (HIE) in term-equivalent perinatal and adult animals. The outcomes were highly inconsistent between studies. Although there were differences in dose and timing of administration, there was evidence that beneficial effects of MgSO4 were associated with confounding mild hypothermia and, strikingly, the studies that included rigorous maintenance of environmental temperature or body temperature consistently suggested a lack of effect. On balance, these preclinical studies suggest that peripherally administered MgSO4 is unlikely to be neuroprotective. Rigorous testing in translational animal models of perinatal HIE is needed before MgSO4 should be considered in clinical trials for encephalopathy in term infants. PMID:24854050

Galinsky, Robert; Bennet, Laura; Groenendaal, Floris; Lear, Christopher A; Tan, Sidhartha; van Bel, Frank; Juul, Sandra E; Robertson, Nicola J; Mallard, Carina; Gunn, Alistair J

2014-01-01

197

Orazipone, a locally acting immunomodulator, ameliorates intestinal radiation injury: A preclinical study in a novel rat model  

SciTech Connect

Purpose: Intestinal radiation injury (radiation enteropathy) is relevant to cancer treatment, as well as to radiation accidents and radiation terrorism scenarios. This study assessed the protective efficacy of orazipone, a locally-acting small molecule immunomodulator. Methods and Materials: Male rats were orchiectomized, a 4-cm segment of small bowel was sutured to the inside of the scrotum, a proximal anteperistaltic ileostomy was created for intraluminal drug administration, and intestinal continuity was re-established by end-to-side anastomosis. After three weeks postoperative recovery, the intestine in the 'scrotal hernia' was exposed locally to single-dose or fractionated X-radiation. Orazipone (30 mg/kg/day) or vehicle was administered daily through the ileostomy, either during and after irradiation, or only after irradiation. Structural, cellular, and molecular aspects of intestinal radiation toxicity were assessed two weeks after irradiation. Results: Orazipone significantly ameliorated histologic injury and transforming growth factor-{beta} immunoreactivity levels, both after single-dose and fractionated irradiation. Intestinal wall thickness was significantly reduced after single-dose and nonsignificantly after fractionated irradiation. Mucosal surface area and numbers of mast cells were partially restored by orazipone after single-dose irradiation. Conclusions: This work (1) demonstrates the utility of the ileostomy rat model for intraluminal administration of response modifiers in single-dose and fractionated radiation studies; (2) shows that mucosal immunomodulation during and/or after irradiation ameliorates intestinal toxicity; and (3) highlights important differences between single-dose and fractionated radiation regimens.

Boerma, Marjan [Department of Surgery, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR (United States); Wang, Junru [Department of Surgery, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR (United States); Richter, Konrad K. [Department of Surgery, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR (United States); Hauer-Jensen, Martin [Department of Surgery, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR (United States) and Department of Pathology, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR (United States)]. E-mail: mhjensen@life.uams.edu

2006-10-01

198

A case study: Analysis of teacher self-efficacy of teacher candidates  

Microsoft Academic Search

The purpose of this study is to analyze the teacher self-efficacy beliefs of the teacher candidates by some variables such as gender and general academic achievement. Twenty nine students participated to this study. Teacher self-efficacy scale and educational software development self-efficacy scale were used as instruments. No significant difference was found between teacher self-efficacy perceptions of teacher candidates according to

Adem Uzun; Rüçhan Özk?l?ç; Aysan ?entürk

2010-01-01

199

Human B-cell cancer cell lines as a preclinical model for studies of drug effect in diffuse large B-cell lymphoma and multiple myeloma.  

PubMed

Drug resistance in cancer refers to recurrent or primary refractory disease following drug therapy. At the cellular level, it is a consequence of molecular functions that ultimately enable the cell to resist cell death-one of the classical hallmarks of cancer. Thus, drug resistance is a fundamental aspect of the cancer cell phenotype, in parallel with sustained proliferation, immortality, angiogenesis, invasion, and metastasis. Here we present a preclinical model of human B-cell cancer cell lines used to identify genes involved in specific drug resistance. This process includes a standardized technical setup for specific drug screening, analysis of global gene expression, and the statistical considerations required to develop resistance gene signatures. The state of the art is illustrated by the first-step classical drug screen (including the CD20 antibody rituximab, the DNA intercalating topoisomerase II inhibitor doxorubicin, the mitotic inhibitor vincristine, and the alkylating agents cyclophosphamide and melphalan) along with the generation of gene lists predicting the chemotherapeutic outcome as validated retrospectively in clinical trial datasets. This B-cell lineage-specific preclinical model will allow us to initiate a range of laboratory studies, with focus on specific gene functions involved in molecular resistance mechanisms. PMID:25072621

Laursen, Maria Bach; Falgreen, Steffen; Bødker, Julie Støve; Schmitz, Alexander; Kjeldsen, Malene Krag; Sørensen, Suzette; Madsen, Jakob; El-Galaly, Tarec Christoffer; Bøgsted, Martin; Dybkær, Karen; Johnsen, Hans Erik

2014-11-01

200

Preservice Elementary Teachers' Perceived Efficacy in Teaching Environmental Education: A Preliminary Study.  

ERIC Educational Resources Information Center

This study was designed to develop an instrument that would measure preservice teachers' belief efficacy in teaching environmental education (EE). This belief efficacy includes a person's perception of ability to perform the behavior (self-efficacy) and a person's expectation that a specific behavior will result in desirable outcomes (outcome…

Sia, Archibald P.

201

Alzheimer's Therapeutics: Translation of Preclinical Science to Clinical Drug Development  

Microsoft Academic Search

Over the past three decades, significant progress has been made in understanding the neurobiology of Alzheimer's disease. In recent years, the first attempts to implement novel mechanism-based treatments brought rather disappointing results, with low, if any, drug efficacy and significant side effects. A discrepancy between our expectations based on preclinical models and the results of clinical trials calls for a

Alena V Savonenko; Tatiana Melnikova; Andrew Hiatt; Tong Li; Paul F Worley; Juan C Troncoso; Phil C Wong; Don L Price

2012-01-01

202

[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  

SciTech Connect

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 {sup 90}Y quantitation with Bremsstrahlung imaging. The study on SPECT discusses attenuation correction and scatter correction. Preclinical studies investigated uptake of {sup 90}Y-BrE-3 in mice using autoradiography. Clinical studies discuss image quantitation verses counts from biopsy samples, S factors for radiation dose calculation, {sup 67}Cu imaging studies for lymphoma cancer, and {sup 111}In MoAb imaging studies for breast cancer to predict {sup 90}Y MoAb therapy.

DeNardo, S.J.

1995-12-31

203

Using [11C]diprenorphine to image opioid receptor occupancy by methadone in opioid addiction: clinical and preclinical studies.  

PubMed

Substitute methadone prescribing is one of the main modes of treatment for opioid dependence with established evidence for improved health and social outcomes. However, the pharmacology underpinning the effects of methadone is little studied despite controversies about dosing in relation to outcome. We therefore examined the relationship between methadone dose and occupation of opioid receptors in brain using the positron emission tomography (PET) radioligand [(11)C]diprenorphine in humans and rats. Eight opioid-dependent subjects stable on their substitute methadone (18-90 mg daily) had an [(11)C]diprenorphine PET scan at predicted peak plasma levels of methadone. These were compared with eight healthy controls. No difference in [(11)C]diprenorphine binding was found between the groups, with no relationship between methadone dose and occupancy. Adult male Sprague-Dawley rats that had been given an acute i.v. injection of methadone hydrochloride (0.35, 0.5, 0.7, or 1.0 mg kg(-1)) before [(11)C]diprenorphine showed a dose-dependent increase in biodistribution but no reduction in [(11)C]diprenorphine binding. We suggest that the lack of a dose-dependent relationship between methadone dose, either given chronically in human or acutely in rat, and occupancy of opioid receptor measured with [(11)C]diprenorphine PET is related to efficacy of this opioid agonist at very low levels of opioid receptor occupancy. This has implications for understanding the actions of methadone in comparison with other opioid drugs such as partial agonists and antagonists. PMID:15347732

Melichar, Jan K; Hume, Susan P; Williams, Tim M; Daglish, Mark R C; Taylor, Lindsay G; Ahmad, Rabia; Malizia, Andrea L; Brooks, David J; Myles, Judith S; Lingford-Hughes, Anne; Nutt, David J

2005-01-01

204

Preclinical assessment of abuse liability of drugs  

Microsoft Academic Search

Studies that are used in preclinical assessment of the liability of a drug to become an abuse problem are reviewed. These studies examine the capacity of a drug to produce physiological dependence or to function as a reinforcer. Studies that examine physiological dependence by assessing whether a drug reverses signs of withdrawal from a standard drug are rapid, reliable and

J. L. Katz; S. R. Goldberg

1988-01-01

205

Preclinical Evaluation of Reconsolidation Blockade by Clonidine as a Potential Novel Treatment for Posttraumatic Stress Disorder  

PubMed Central

Exposure to traumatic events can lead to posttraumatic stress disorder (PTSD). Current PTSD treatments typically only produce partial improvement. Hence, there is a need for preclinical research to identify new candidate drugs and to develop novel therapeutic approaches. Animal studies have indicated that fear memories can be weakened by blocking restabilization after retrieval, a process known as reconsolidation. Furthermore, evidence suggests that there are important alterations of the noradrenergic system in PTSD, and hence it may be of interest to study drugs that target this pathway. Here, we investigated the efficacy of clonidine, an ?2-adrenoreceptor agonist, to block reconsolidation in an animal model of persistent traumatic memories. Using an auditory fear conditioning paradigm in rats, we tested the efficacy of clonidine to weaken fear memory retention when administered systemically after retrieval. We evaluated dosage, number of treatments, and specificity in reconsolidation blockade. We found that postretrieval administration of clonidine disrupts fear-related memories in a dose-dependent manner and that two treatments are sufficient for maximal memory impairment. Furthermore, we determined that this effect is long lasting and specific to reconsolidation processes as shown by the selectivity to affect reactivated memories and the absence of spontaneous recovery and of postreactivation short-term memory impairment. Our results demonstrate the efficacy of systemic administration of clonidine following retrieval to persistently disrupt fear memory retention through reconsolidation blockade. This study provides important preclinical parameters for future therapeutic strategies involving clonidine to block reconsolidation as a novel treatment for PTSD symptoms. PMID:22871915

Gamache, Karine; Pitman, Roger K; Nader, Karim

2012-01-01

206

L-Histidinol: Preclinical Therapeutic Studies in Combination with Antitumor Agents and Pharmacokinetic Studies in Mice1  

Microsoft Academic Search

Therapeutic studies were conducted with L-histidinol, in combination with cyclophosphamide, bischloroethylnitrosourea, 5-fluorouracil, phen- ylalanine mustard, or m-platinum(H)diammine dichloride, in several transplantable tumors in mice. These tumor types included murine LI 210 P388 leukemias, M5076 sarcoma, mammary 16\\/C adenocarcinoma, hu man LOX melanoma, and colon III-29 adenocarcinoma. Therapeutic benefits of adding i.-histidinol to a regimen, compared to the regimen alone, were

Daniel Zaharko; Jacqueline Plowman; William VVaud; Donald Dykes; Louis Malspeis

207

Pre-clinical diastolic dysfunction.  

PubMed

Pre-clinical diastolic dysfunction (PDD) has been broadly defined as left ventricular diastolic dysfunction without the diagnosis of congestive heart failure (HF) and with normal systolic function. PDD is an entity that remains poorly understood, yet has definite clinical significance. Although few original studies have focused on PDD, it has been shown that PDD is prevalent, and that there is a clear progression from PDD to symptomatic HF including dyspnea, edema, and fatigue. In diabetic patients and in patients with coronary artery disease or hypertension, it has been shown that patients with PDD have a significantly higher risk of progression to heart failure and death compared with patients without PDD. Because of these findings and the increasing prevalence of the heart failure epidemic, it is clear that an understanding of PDD is essential to decreasing patients' morbidity and mortality. This review will focus on what is known concerning pre-clinical diastolic dysfunction, including definitions, staging, epidemiology, pathophysiology, and the natural history of the disease. In addition, given the paucity of trials focused on PDD treatment, studies targeting risk factors associated with the development of PDD and therapeutic trials for heart failure with preserved ejection fraction will be reviewed. PMID:24291270

Wan, Siu-Hin; Vogel, Mark W; Chen, Horng H

2014-02-11

208

Behavioral pharmacology of cannabinoids with a focus on preclinical models for studying reinforcing and dependence-producing properties.  

PubMed

Cannabis preparations as recreational drugs are the most widely used illicit drugs in the world. Although cannabis derivatives produce clear subjective motivational responses in humans leading to drug-seeking behavior and in a specific proportion in repeated drug use, the reinforcing/rewarding attributes of these subjective effects are difficult to define in experimental animals. This led to the notion of cannabinoids being considered as "atypical" or "anomalous" drugs of abuse. To this end, our knowledge and understanding of the way cannabis and its main psychoactive constituent, Delta(9)-tetrahydrocannabinol (Delta(9)-THC), act in the central nervous system to exert their reinforcing/rewarding effects is far from complete. The aim of the present article is to review from a preclinical perspective the current status of what is known about the behavioral pharmacology of cannabinoids including the recently identified cannabinoid neurotransmission modifiers with a particular emphasis on their motivational/reinforcing and dependence-producing properties. We conclude that cannabinoids exhibit reinforcing/rewarding properties in experimental animals mostly under particular experimental conditions, which is not the case for other drugs of abuse, such as opiates, psychostimulants, alcohol and nicotine. The paper will discuss these findings critically and also point to open questions that should be addressed in the future in order to improve our understanding of these specific actions of cannabinoids that will also impact drug discovery and development efforts of related compounds as therapeutics in the clinic. PMID:19630731

Panagis, George; Vlachou, Styliani; Nomikos, George G

2008-11-01

209

Novel liquid chromatographic method for simultaneous estimation of pioglitazone and glimepiride in rat plasma by solid phase extraction: application to preclinical pharmacokinetic studies.  

PubMed

The need for a reliable bioanalytical method is of primary importance during preclinical studies. The aim of the present study was simultaneous determination of pioglitazone (CAS 111025-46-8) (PIO) and glimepiride (CAS 93479-97-1) (GLM) in plasma of rats. A high-performance liquid chromatographic method has been developed and validated using C18 column and UV detector. A mobile phase composed of acetonitrile and ammonium acetate buffer pH 4.5 in the ratio of 55:45%. The plasma samples clean-up was carried out using solid phase cartridges. The method was in the linear range of 50-8000 ng/mL for PIO and 50-2000 ng/mL for GLM. The coefficient of regression was found to be > or = 0.99. Precision and accuracy were within the acceptable limits, as indicated by relative standard deviation varying from 1.5 to 6.1% for PIO and 3.1 to 7.0% for GLM whereas the accuracy ranged from 97.0 to 106.4% for PIO and 96.5 to 106.4% for GLM. The mean extraction recovery was found to be 90.2 +/- 4.5, 76.8 +/- 2.8 and 85.2 +/- 5.2% for PIO, GLM and internal standard, respectively. Moreover, PIO and GLM were stable in plasma, up to 30 days of storage at -70 degrees C and after being subjected to bench top, auto-sampler, and three freeze-thaw cycles. The developed method was applied for preclinical pharmacokinetic studies. PMID:21355443

Musmade, Prashant B; Talole, Kranti B; Deshpande, Praful B; Karthik, Arumugam; Pathak, Shriram M; Pandey, Sureshwar; Udupa, Nayanabhirama

2011-01-01

210

Porcine adipose-derived stem cells from buccal fat pad and subcutaneous adipose tissue for future preclinical studies in oral surgery  

PubMed Central

Introduction Adipose-derived stem cells (ASCs) are progenitor cells used in bone tissue engineering and regenerative medicine. Despite subcutaneous adipose tissue being more abundant, the buccal fat pad (BFP) is easily accessible for dentists and maxillofacial surgeons. For this reason, considering the need for preclinical study and the swine as an optimal animal model in tissue engineering applications, we compared the features of porcine ASCs (pASCs) from both tissue-harvesting sites. Methods ASCs were isolated from interscapular subcutaneous adipose tissue (ScI) and buccal fat pads of six swine. Cells were characterized for their stemness and multipotent features. Moreover, their osteogenic ability when cultured on titanium disks and silicon carbide-plasma-enhanced chemical vapor-deposition fragments, and their growth in the presence of autologous and heterologous serum were also assessed. Results Independent of the harvesting site, no differences in proliferation, viability, and clonogenicity were observed among all the pASC populations. Furthermore, when induced toward osteogenic differentiation, both ScI- and BFP-pASCs showed an increase of collagen and calcified extracellular matrix (ECM) production, alkaline phosphatase activity, and osteonectin expression, indicating their ability to differentiate toward osteoblast-like cells. In addition, they differentiated toward adipocyte-like cells, and chondrogenic induced pASCs were able to increase glycosaminoglycans (GAGs) production over time. When cells were osteoinduced on synthetic biomaterials, they significantly increased the amount of calcified ECM compared with control cells; moreover, titanium showed the osteoinductive effect on pASCs, also without chemical stimuli. Finally, these cells grew nicely in 10% FBS, and no benefits were produced by substitution with swine serum. Conclusions Swine buccal fat pad contains progenitor cells with mesenchymal features, and they also osteo-differentiate nicely in association with synthetic supports. We suggest that porcine BFP-ASCs may be applied in preclinical studies of periodontal and bone-defect regeneration. PMID:24330736

2013-01-01

211

Preclinical and clinical research on inflammation after intracerebral hemorrhage  

PubMed Central

Intracerebral hemorrhage (ICH) is one of the most lethal stroke subtypes. Despite the high morbidity and mortality associated with ICH, its pathophysiology has not been investigated as well as that of ischemic stroke. Available evidence from preclinical and clinical studies suggests that inflammatory mechanisms are involved in the progression of ICH-induced secondary brain injury. For example, in preclinical ICH models, microglial activation has been shown to occur within 1 h, much earlier than neutrophil infiltration. Recent advances in our understanding of neuroinflammatory pathways have revealed several new molecular targets, and related therapeutic strategies have been tested in preclinical ICH models. This review summarizes recent progress made in preclinical models of ICH, surveys preclinical and clinical studies of inflammatory cells (leukocytes, macrophages, microglia, and astrocytes) and inflammatory mediators (matrix metalloproteinases, nuclear factor erythroid 2-related factor 2, heme oxygenase, and iron), and highlights the emerging areas of therapeutic promise. PMID:20713126

Wang, Jian

2010-01-01

212

Comparative Effectiveness of 3-Dimensional vs 2-Dimensional and High-Definition vs Standard-Definition Neuroendoscopy: A Preclinical Randomized Crossover Study  

PubMed Central

BACKGROUND: Although the potential benefits of 3-dimensional (3-D) vs 2-dimensional (2-D) and high-definition (HD) vs standard-definition (SD) endoscopic visualization have long been recognized in other surgical fields, such endoscopes are generally considered too large and bulky for use within the brain. The recent development of 3-D and HD neuroendoscopes may therefore herald improved depth perception, better appreciation of anatomic details, and improved overall surgical performance. OBJECTIVE: To compare simultaneously the effectiveness of 3-D vs 2-D and HD vs SD neuroendoscopy. METHODS: Ten novice neuroendoscopic surgeons were recruited from a university hospital. A preclinical randomized crossover study design was adopted to compare 3-D vs 2-D and HD vs SD neuroendoscopy. The primary outcomes were time to task completion and accuracy. The secondary outcomes were perceived task workload using the NASA (National Aeronautics and Space Administration) Task Load Index and subjective impressions of the endoscopes using a 5-point Likert scale. RESULTS: Time to task completion was significantly shorter when using the 3-D vs the 2-D neuroendoscopy (P = .001), and accuracy of probe placement was significantly greater when using the HD vs the SD neuroendoscopy (P = .009). We found that 3-D endoscopy significantly improved perceived depth perception (P < .001), HD endoscopy significantly improved perceived image quality (P < .001), and both improved participants’ overall impression (P < .001). CONCLUSION: Three-dimensional neuroendoscopy and HD neuroendoscopy have differing but complementary effects on surgical performance, suggesting that neither alone can completely compensate for the lack of the other. There is therefore strong preclinical evidence to justify 3-D HD neuroendoscopy. ABBREVIATIONS: HD, high definition SD, standard definition PMID:24220007

Hughes-Hallett, Archie; Cundy, Thomas P.; Di Marco, Aimee; Pratt, Philip; Nandi, Dipankar; Darzi, Ara; Yang, Guang-Zhong

2013-01-01

213

Efficacy of particle repositioning maneuver in BPPV: a prospective study  

Microsoft Academic Search

PurposeA single blinded prospective randomized controlled trial was conducted in 40 patients with benign paroxysmal positional vertigo (BPPV) to determine the efficacy of particle repositioning maneuver (PRM).

Sridhar Simhadri; Naresh Panda; Meena Raghunathan

2003-01-01

214

Efficacy of Zolpidem for Dystonia: A Study Among Different Subtypes  

PubMed Central

Although there are some newly developed options to treat dystonia, its medical treatment is not always satisfactory. Zolpidem, an imidazopyridine agonist with a high affinity on benzodiazepine subtype receptor BZ1 (?1), was found to improve clinical symptoms of dystonia in a limited number of case reports. To investigate what subtype of dystonia is responsive to the therapy, we conducted an open label study to assess the efficacy of zolpidem (5–20?mg) in 34 patients suffering from miscellaneous types of dystonia using the Burke–Fahn–Marsden Dystonia Rating Scale (BFMDRS). Patients were entered into the study if they had been refractory to other medications as evaluated by BFMDRS (no change in the previous two successive visits). After zolpidem therapy, the scores in the patients as a whole were decreased from 7.2?±?7.9 to 5.5?±?5.0 (P?=?0.042). Patients with generalized dystonia, Meige syndrome/blepharospasm, and hand dystonia improved in the scale by 27.8, 17.8, and 31.0%, respectively, whereas no improvement was found in cervical dystonia patients. Overall response rate among patients were comparable to that of trihexyphenidyl. Zolpidem may be a therapeutic option for generalized dystonia, Meige syndrome, and hand dystonia including musician’s. Drowsiness was the dose-limiting factor. PMID:22529836

Miyazaki, Yoshimichi; Sako, Wataru; Asanuma, Kotaro; Izumi, Yuishin; Miki, Tetsuro; Kaji, Ryuji

2012-01-01

215

Preclinical safety of anecortave acetate.  

PubMed

A number of preclinical safety pharmacology and toxicity studies have been performed on the angiostatic cortisene anecortave acetate in various species and using different routes of administration (oral, intravenous, subcutaneous, topical ocular, intraocular injection, posterior juxtascleral) and a wide range of doses (0-1,000 mg/kg). Anecortave acetate did not interact with a broad panel of pharmacological receptors and had no apparent pharmacological effects on major organ systems including the central nervous, gastrointestinal, renal, cardiovascular, and respiratory systems. Oral, topical ocular, and posterior juxtascleral administration of anecortave acetate had no significant ocular or systemic side effects or toxicity. In addition, there was no significant carcinogenic or reproductive/developmental toxicity associated with anecortave acetate in genotoxicity, carcinogenicity, and reproductive toxicity studies. PMID:17240255

Heaton, Jim; Kastner, Philip; Hackett, Robert

2007-01-01

216

Multilateral in vivo and in vitro protective effects of the novel heat shock protein coinducer, bimoclomol: results of preclinical studies.  

PubMed

Bimoclomol, the recently developed non-toxic heat shock protein (HSP) coinducer, was shown to display multilateral protective activities against various forms of stress or injuries at the level of the cell, tissue or organism. The compound enhanced the transcription, translation and expression of the 70 kD heat shock protein (HSP-70) in myogenic and HeLa cell lines exposed to heat stress, and increased cell survival on exposure to otherwise lethal thermal injury. Bimoclomol increased contractility of the working mammalian heart, this effect was associated with the increased intracellular calcium transients due to increased probability of opening of ryanodine receptors in the sarcoplasmic reticulum (SR). In healthy tissues these cardiac effects were evident only at relatively high concentrations of the drug, while in the ischemic myocardium bimoclomol exerted significant cardioprotective and antiarrhythmic effects at submicromolar concentrations. It decreased ischemia-induced reduction of contractility and of cardiac output, and dramatically decreased the elevation of the ST-segment during ischemia as well as the occurrence of ventricular fibrillation upon reperfusion. Bimoclomol was also active in various pathological animal models subjected to acute or chronic stress. In the spontaneously hypertensive rats chronic pretreatment with bimoclomol restored sensitivity of aortic rings to acetylcholine; this effect was accompanied by accumulation of HSP-70 in the tissues. Bimoclomol pretreatment significantly diminished the consequences of vascular disorders associated with diabetes mellitus. Diabetic neuropathy, retinopathy, and nephropathy were prevented or diminished, while wound healing was enhanced by bimoclomol. Enhancement of wound healing by bimoclomol was observed after thermal injury as well as following ultraviolet (UV) irradiation. In addition to the beneficial effects on peripheral angiopathies, bimoclomol antagonized the increase in permeability of blood-brain barrier induced by subarachnoid hemorrhager or arachidonic acid. A general and very important feature of the above effects of bimoclomol was that the drug failed to cause alterations under physiological conditions (except the enhanced calcium release from cardiac sarcoplasmic reticulum). Bimoclomol was effective only under conditions of stress. Consistent with its HSP-coinducer property, bimoclomol alone had very little effect on HSP production. Its protective activity became apparent only in the presence of cell damage. Currently, bimoclomol reached the end of the Phase II clinical trial in a group of 410 patients with diabetic complications. Results of this trial will answer the question, whether a compound with promising in vitro and in vivo preclinical findings will produce the anticipated beneficial effects in humans. In the event of a positive outcome of this trial, the indications for bimoclomol will be substantially extended. PMID:11484067

Nánási, P P; Jednákovits, A

2001-01-01

217

A longitudinal study of teacher burnout and perceived self-efficacy in classroom management  

Microsoft Academic Search

This study examined the direction and time-frame of relationships between perceived self-efficacy in classroom management and the three dimensions of burnout among 243 secondary school teachers. Structural equation modeling (SEM) analyses indicated that perceived self-efficacy had a longitudinal effect on depersonalization and a synchronous effect on personal accomplishment. However, the direction was reversed for the relationship between perceived self-efficacy and

André Brouwers; Welko Tomic

2000-01-01

218

Emotional intelligence and teacher efficacy: a study of Turkish EFL pre-service teachers  

Microsoft Academic Search

This study investigated the relationship between emotional intelligence and teacher efficacy among 90 English language pre-service teachers from a university in Turkey. Data sources included Tschannen-Moran and Woolfolk-Hoy’s Teachers’ Sense of Efficacy Scale and Reuven Bar-On’s Emotional Quotient Inventory. The findings indicated that Turkish EFL pre-service teachers felt more efficacious in managing the class rather than in making the class

Zeynep Koço?lu

2011-01-01

219

Efficacy of Counseling and Psychotherapy in Schools: A Meta-Analytic Review of Treatment Outcome Studies  

ERIC Educational Resources Information Center

This study investigated the efficacy of counseling and psychotherapy interventions for youth in schools. Data were examined for 107 studies that included 132 treatment interventions. Overall efficacy was d = 0.45 and was significantly different from zero. Interventions for adolescents outperformed those of children, treatment groups that were…

Baskin, Thomas W.; Slaten, Christopher D.; Crosby, Nicole R.; Pufahl, Tiffany; Schneller, Cali L.; Ladell, Monica

2010-01-01

220

Teacher Efficacy: A Comparative Study of Hong Kong and Shanghai Primary In-Service Teachers  

ERIC Educational Resources Information Center

Teachers beliefs about their ability to affect students' performance is an important part of professionalism. This study compared 725 Hong Kong and 575 Shanghai primary in-service teachers on their teacher efficacy. Two Chinese versions of the 12-item Teachers' Sense of Efficacy Scale were used in this study since some wordings of the Hong Kong…

Cheung, Hoi Yan

2008-01-01

221

Pre-Clinical Models of Acquired Neonatal Seizures: Differential Effects of Injury on Function of Chloride Co-Transporters  

PubMed Central

Hypoxic-ischemic encephalopathy [HIE] represents the most common acquired pathology associated with neonatal seizures. HIE-associated neonatal seizures are often difficult to control, due to their refractoriness to traditional anti-seizure agents. Developmentally regulated chloride gradients during early development make the neonatal brain more seizure-susceptible by depolarizing GABAAR-mediated currents, and therefore hindering inhibition by conventional anti-seizure drugs such as phenobarbital [PB] and benzodiazepines. Pharmaco-modulation of chloride co-transporters has become a current field of research in treating refractory neonatal seizures, and the basis of two clinical trials [NCT01434225; NCT00380531]. However, the recent termination of NEMO study [NCT01434225] on bumetanide, an NKCC1 antagonist, suggests that clinical utilization of bumetanide as an adjunct to treat neonatal seizures with PB may not be a viable option. Hence, re-evaluation of bumetanide as an adjunct through pre-clinical studies is warranted. Additionally, the model-specific variability in the efficacy of bumetanide in the pre-clinical models of neonatal seizures highlights the differential consequences of insults used to induce seizures in each pre-clinical model as worth exploration. Injury itself can significantly alter the function of chloride co-transporters, and therefore the efficacy of anti-seizure agents that follow.

Kang, SK; Kadam, SD

2014-01-01

222

Preclinical development of monoclonal antibodies  

PubMed Central

The development of mAbs remains high on the therapeutic agenda for the majority of pharmaceutical and biotechnology companies. Often, the only relevant species for preclinical safety assessment of mAbs are non-human primates (NHPs), and this raises important scientific, ethical and economic issues. To investigate evidence-based opportunities to minimize the use of NHPs, an expert working group with representatives from leading pharmaceutical and biotechnology companies, contract research organizations and institutes from Europe and the USA, has shared and analyzed data on mAbs for a range of therapeutic areas. This information has been applied to hypothetical examples to recommend scientifically appropriate development pathways and study designs for a variety of potential mAbs. The addendum of ICHS6 provides a timely opportunity for the scientific and regulatory community to embrace strategies which minimize primate use and increase efficiency of mAb development. PMID:20065651

Pullen, Nick; Coney, Lee; Dempster, Maggie; Andrews, Laura; Bajramovic, Jeffrey; Baldrick, Paul; Buckley, Lorrene; Jacobs, Abby; Hale, Geoff; Green, Colin; Ragan, Ian; Robinson, Vicky

2009-01-01

223

Non-invasive molecular imaging for preclinical cancer therapeutic development  

PubMed Central

Molecular and non-invasive imaging are rapidly emerging fields in preclinical cancer drug discovery. This is driven by the need to develop more efficacious and safer treatments, the advent of molecular-targeted therapeutics, and the requirements to reduce and refine current preclinical in vivo models. Such bioimaging strategies include MRI, PET, single positron emission computed tomography, ultrasound, and optical approaches such as bioluminescence and fluorescence imaging. These molecular imaging modalities have several advantages over traditional screening methods, not least the ability to quantitatively monitor pharmacodynamic changes at the cellular and molecular level in living animals non-invasively in real time. This review aims to provide an overview of non-invasive molecular imaging techniques, highlighting the strengths, limitations and versatility of these approaches in preclinical cancer drug discovery and development. PMID:23488622

O'Farrell, AC; Shnyder, SD; Marston, G; Coletta, PL; Gill, JH

2013-01-01

224

Changes in self-efficacy and dietary adherence: the impact on weight loss in the PREFER study  

Microsoft Academic Search

Findings from studies examining self-efficacy and its relationship to weight loss have been inconsistent. We examined self-efficacy\\u000a specific to changing eating behaviors in the PREFER trial, an 18-month behavioral weight-loss study, to determine if self-efficacy\\u000a and dietary adherence were associated with weight change, and what impact self-efficacy had on weight change after controlling\\u000a for adherence. Measurements included the weight efficacy

Melanie T. Warziski; Susan M. Sereika; Mindi A. Styn; Lora E. Burke

2008-01-01

225

Preclinical molecular imaging of tumor angiogenesis.  

PubMed

Angiogenesis, a course that new blood vessels grow from the existing vasculature, plays important roles both physiologically and pathologically. Angiogenesis can be switched on by growth factors secreted by tumor cells, and in turn supplies more oxygen and nutrition to the tumor. More and more preclinical studies and clinical trials have shown that inhibition of angiogenesis is an effective way to inhibit tumor growth, substantiating the development of anti-angiogenesis therapeutics. Imaging technologies accelerate the translation of preclinical research to the clinic. In oncology, various imaging modalities are widely applied to drug development, tumor early detection and therapy response monitoring. So far, several angiogenesis related imaging agents are promising in cancer diagnosis. However, more effective imaging agents with less side-effect still need to be pursued to visualize angiogenesis process non-invasively. The main purpose of this review is to summarize the recent progresses in preclinical molecular imaging of angiogenesis and to discuss the potential of the current preclinical probes specific to various angiogenesis targets including vascular endothelial growth factor and its receptors (VEGF/VEGFRs), integrin avb3 and matrix metalloproteinases (MMPs). It is predictable that related investigations in the field will benefit cancer research and quicken the anti-angiogenic drug development. PMID:20639815

Zhu, L; Niu, G; Fang, X; Chen, X

2010-06-01

226

Preclinical Cardiorenal Interrelationships in Essential Hypertension  

PubMed Central

A diseased heart causes numerous adverse effects on kidney function, and vice versa renal disease can significantly impair cardiac function. Beyond these heart-kidney interrelationships at the clinical level, a reciprocal association has been suggested to exist even in the early stages of those organs' dysfunction. The aim of the present review is to provide evidence of the presence of a preclinical cardiorenal syndrome in the particular setting of essential hypertension, focusing on the subsequent hypertensive sequelae on heart and kidneys. In particular, a plethora of studies have demonstrated not only the predictive role of kidney damage, as expressed by either decreased glomerular filtration or increased urine albumin excretion, for adverse left ventricular functional and structural adaptations but also preclinical heart disease, i.e. left ventricular hypertrophy that is associated with deterioration of renal function. Notably, these reciprocal interactions seem to exist even at the level of microcirculation, since both coronary flow reserve and renal hemodynamics are strongly related with clinical and preclinical renal and cardiac damage, respectively. In this preclinical setting, common pathophysiological denominators, including the increased hemodynamic load, sympathetic and renin-angiotensin system overactivity, increased subclinical inflammatory reaction, and endothelial dysfunction, account not only for the reported associations between overt cardiac and renal damage but also for the parallel changes that occur in coronary and renal microcirculation. PMID:23946723

Tsioufis, Costas; Tsiachris, Dimitrios; Kasiakogias, Alexandros; Dimitriadis, Kyriakos; Petras, Dimitris; Goumenos, Dimitris; Siamopoulos, Konstantinos; Stefanadis, Christodoulos

2013-01-01

227

System Vaccinology for the Evaluation of Influenza Vaccine Safety by Multiplex Gene Detection of Novel Biomarkers in a Preclinical Study and Batch Release Test  

PubMed Central

Vaccines are beneficial and universal tools to prevent infectious disease. Thus, safety of vaccines is strictly evaluated in the preclinical phase of trials and every vaccine batch must be tested by the National Control Laboratories according to the guidelines published by each country. Despite many vaccine production platforms and methods, animal testing for safety evaluation is unchanged thus far. We recently developed a systems biological approach to vaccine safety evaluation where identification of specific biomarkers in a rat pre-clinical study evaluated the safety of vaccines for pandemic H5N1 influenza including Irf7, Lgals9, Lgalsbp3, Cxcl11, Timp1, Tap2, Psmb9, Psme1, Tapbp, C2, Csf1, Mx2, Zbp1, Ifrd1, Trafd1, Cxcl9, ?2m, Npc1, Ngfr and Ifi47. The current study evaluated whether these 20 biomarkers could evaluate the safety, batch-to-batch and manufacturer-to-manufacturer consistency of seasonal trivalent influenza vaccine using a multiplex gene detection system. When we evaluated the influenza HA vaccine (HAv) from four different manufactures, the biomarker analysis correlated to findings from conventional animal use tests, such as abnormal toxicity test. In addition, sensitivity of toxicity detection and differences in HAvs were higher and more accurate than with conventional methods. Despite a slight decrease in body weight caused by HAv from manufacturer B that was not statistically significant, our results suggest that HAv from manufacturer B is significantly different than the other HAvs tested with regard to Lgals3bp, Tapbp, Lgals9, Irf7 and C2 gene expression in rat lungs. Using the biomarkers confirmed in this study, we predicted batch-to-batch consistency and safety of influenza vaccines within 2 days compared with the conventional safety test, which takes longer. These biomarkers will facilitate the future development of new influenza vaccines and provide an opportunity to develop in vitro methods of evaluating batch-to-batch consistency and vaccine safety as an alternative to animal testing. PMID:25010690

Mizukami, Takuo; Momose, Haruka; Kuramitsu, Madoka; Takizawa, Kazuya; Araki, Kumiko; Furuhata, Keiko; Ishii, Ken J.; Hamaguchi, Isao; Yamaguchi, Kazunari

2014-01-01

228

Ultrasound guided fluorescence molecular tomography with improved quantification by an attenuation compensated born-normalization and in vivo preclinical study of cancer  

SciTech Connect

Ultrasound imaging, having the advantages of low-cost and non-invasiveness over MRI and X-ray CT, was reported by several studies as an adequate complement to fluorescence molecular tomography with the perspective of improving localization and quantification of fluorescent molecular targets in vivo. Based on the previous work, an improved dual-modality Fluorescence-Ultrasound imaging system was developed and then validated in imaging study with preclinical tumor model. Ultrasound imaging and a profilometer were used to obtain the anatomical prior information and 3D surface, separately, to precisely extract the tissue boundary on both sides of sample in order to achieve improved fluorescence reconstruction. Furthermore, a pattern-based fluorescence reconstruction on the detection side was incorporated to enable dimensional reduction of the dataset while keeping the useful information for reconstruction. Due to its putative role in the current imaging geometry and the chosen reconstruction technique, we developed an attenuation compensated Born-normalization method to reduce the attenuation effects and cancel off experimental factors when collecting quantitative fluorescence datasets over large area. Results of both simulation and phantom study demonstrated that fluorescent targets could be recovered accurately and quantitatively using this reconstruction mechanism. Finally, in vivo experiment confirms that the imaging system associated with the proposed image reconstruction approach was able to extract both functional and anatomical information, thereby improving quantification and localization of molecular targets.

Li, Baoqiang; Berti, Romain; Abran, Maxime; Lesage, Frédéric, E-mail: frederic.lesage@polymtl.ca [Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7 (Canada) [Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7 (Canada); Montreal Heart Institute, Montreal, Quebec H1T 1C8 (Canada)

2014-05-15

229

Ultrasound guided fluorescence molecular tomography with improved quantification by an attenuation compensated born-normalization and in vivo preclinical study of cancer  

NASA Astrophysics Data System (ADS)

Ultrasound imaging, having the advantages of low-cost and non-invasiveness over MRI and X-ray CT, was reported by several studies as an adequate complement to fluorescence molecular tomography with the perspective of improving localization and quantification of fluorescent molecular targets in vivo. Based on the previous work, an improved dual-modality Fluorescence-Ultrasound imaging system was developed and then validated in imaging study with preclinical tumor model. Ultrasound imaging and a profilometer were used to obtain the anatomical prior information and 3D surface, separately, to precisely extract the tissue boundary on both sides of sample in order to achieve improved fluorescence reconstruction. Furthermore, a pattern-based fluorescence reconstruction on the detection side was incorporated to enable dimensional reduction of the dataset while keeping the useful information for reconstruction. Due to its putative role in the current imaging geometry and the chosen reconstruction technique, we developed an attenuation compensated Born-normalization method to reduce the attenuation effects and cancel off experimental factors when collecting quantitative fluorescence datasets over large area. Results of both simulation and phantom study demonstrated that fluorescent targets could be recovered accurately and quantitatively using this reconstruction mechanism. Finally, in vivo experiment confirms that the imaging system associated with the proposed image reconstruction approach was able to extract both functional and anatomical information, thereby improving quantification and localization of molecular targets.

Li, Baoqiang; Berti, Romain; Abran, Maxime; Lesage, Frédéric

2014-05-01

230

Academic Self-Efficacy as a Predictor of College Outcomes: Two Incremental Validity Studies  

ERIC Educational Resources Information Center

A growing body of literature supports the relationship between students' self-efficacy beliefs for academic tasks and milestones and their academic performance. Not surprisingly, some researchers have investigated the role that academic self-efficacy beliefs play in predicting college success. Two incremental validity studies were conducted to…

Gore, Paul A. Jr

2006-01-01

231

Developing Teaching Self-Efficacy in Research Institutions: A Study of Award-Winning Professors  

ERIC Educational Resources Information Center

The purpose of this study was to assess the sources of award-wining research professors' (six women; six men) teaching self-efficacy through the framework of Bandura's (1986) social cognitive theory. Semi-structured interviews revealed that mastery experiences and social persuasions were particularly influential sources of self-efficacy and that…

Morris, David B.; Usher, Ellen L.

2011-01-01

232

A Confirmatory Study of Rating Scale Category Effectiveness for the Coaching Efficacy Scale  

ERIC Educational Resources Information Center

This study extended validity evidence for measures of coaching efficacy derived from the Coaching Efficacy Scale (CES) by testing the rating scale categorizations suggested in previous research. Previous research provided evidence for the effectiveness of a four-category (4-CAT) structure for high school and collegiate sports coaches; it also…

Myers, Nicholas D.; Feltz, Deborah L.; Wolfe, Edward W.

2008-01-01

233

Gender, Group Composition, Cooperation, and Self-Efficacy in Computer Studies.  

ERIC Educational Resources Information Center

Describes a study of Norwegian college students that investigated whether gender, group composition, or self-efficacy in computing has any impact on cooperation, giving or getting task-related help, and level of activity in student groups. Results confirms gender differences in self-efficacy in computing. (Author/LRW)

Busch, Tor

1996-01-01

234

Education for Sustainability: A Case Study of Preservice Primary Teachers' Knowledge and Efficacy  

ERIC Educational Resources Information Center

This study investigated the relationships between knowledge and efficacy for teaching sustainability in a sample of 266 pre-service primary teachers at a large, metropolitan university in Australia. A survey gathered information about the participant's attitudes and self-efficacy for education for sustainability, along with their perceived…

Effeney, Gerard; Davis, Julie

2013-01-01

235

Organizational Structure, Collegial Trust, and College Faculty Teaching Efficacy: A Case Study  

ERIC Educational Resources Information Center

The purpose of this mixed-method study was to explore the relationship between faculty self-efficacy, organizational structure, and collegial trust. The concepts of teacher self-efficacy, organizational structure, and collegial trust were used to investigate any possible empirical relationships existing between these variables in a private,…

Okpogba, Desmond

2011-01-01

236

The Impact of Study Abroad on Students' Self-Efficacy Perceptions  

ERIC Educational Resources Information Center

This article reports the findings of an investigation into the impact of study abroad experiences on self-efficacy perceptions among foreign language (FL) learners. Thirty-nine American college students taking part in both short-term and semester-long academic programs in France and Spain completed self-efficacy surveys at the beginning and at the…

Cubillos, Jorge H.; Ilvento, Thomas

2012-01-01

237

Using Mathematics in Teaching Science Self-Efficacy Scale--UMSSS: A Validity and Reliability Study  

ERIC Educational Resources Information Center

In this study, an instrument, Using Mathematics in Science Self-efficacy Scale (UMSSS), was developed in order to determine preservice science teachers' self-efficacy toward the use of mathematics in their lessons. Data gathered from 250 preservice science teachers were used for Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis…

Can, Bilge Taskin; Gunhan, Berna Canturk; Erdal, Sevinc Ongel

2012-01-01

238

A Reliability Generalization Study of the Teacher Efficacy Scale and Related Instruments  

Microsoft Academic Search

Teacher efficacy has proven to be an important variable in teacher effectiveness. It is consistently related to positive teaching behaviors and student outcomes. However, the measurement of this construct is the subject of current debate, which includes critical examination of predominant instruments used to assess teacher efficacy. The present study extends this critical evaluation and examines sources of measurement error

Robin K. Henson; Lori R. Kogan; Tammi Vacha-Haase

2001-01-01

239

A correlational study of teacher efficacy and school performance in six metropolitan Nashville public high schools  

Microsoft Academic Search

The purpose of this study was to determine whether or not there is a relationship between teacher efficacy and school performance. The subjects were certified personnel from six high schools in the Metropolitan Nashville Public School District. The review of literature included high-stakes testing, accountability, teacher efficacy, school performance, educational reform, and interventions and strategies being used by the states.

Deborah Lyneen Smith

2002-01-01

240

A Gender Study Investigating Physics Self-Efficacy  

ERIC Educational Resources Information Center

The underrepresentation of women in physics has been well documented and a source of concern for both policy makers and educators. My dissertation focuses on understanding the role self-efficacy plays in retaining students, particularly women, in introductory physics. I use an explanatory mixed methods approach to first investigate quantitatively…

Sawtelle, Vashti

2011-01-01

241

Rapid and sensitive ultra-high-pressure liquid chromatography method for quantification of antichagasic benznidazole in plasma: application in a preclinical pharmacokinetic study.  

PubMed

Benznidazole (BNZ) and nifurtimox are the only drugs available for treating Chagas disease. In this work, we validated a bioanalytical method for the quantification of BNZ in plasma aimed at improving sensitivity and time of analysis compared with the assays already published. Furthermore, we demonstrated the application of the method in a preclinical pharmacokinetic study after administration of a single oral dose of BNZ in Wistar rats. A Waters® Acquity UHPLC system equipped with a UV-vis detector was employed. The method was established using an Acquity® UHPLC HSS SB C18 protected by an Acquity® UHPLC HSS SB C18 VanGuard guard column and detection at 324 nm. The mobile phase consisted of ultrapure water-acetonitrile (65:35), and elution was isocratic. The mobile phase flow rate was 0.55 mL/min, the volume of injection was 1 ?L, and the run time was just 2 min. The samples were kept at 25°C until injection and the column at 45°C for the chromatographic separation. The sample preparation was performed by a rapid protein precipitation with acetonitrile. The linear concentration range was 0.15-20 µg/mL. The pharmacokinetic parameters of BNZ in rats were determined and the method was considered sensitive, fast and suitable for application in pharmacokinetic studies. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25424984

Davanço, Marcelo Gomes; de Campos, Michel Leandro; Peccinini, Rosângela Gonçalves

2014-11-26

242

Preclinical studies characterizing the anti-migraine and cardiovascular effects of the selective 5-HT1D receptor agonist PNU-142633.  

PubMed

The present study describes the preclinical pharmacology of a highly selective 5-HT1D receptor agonist PNU-142633. PNU-142633 binds with a Ki of 6 nm at the human 5-HT1D receptor and a Ki of> 18 000 nm at the human 5-HT1B receptor. The intrinsic activity of PNU-142633 at the human 5-HT1D receptor was determined to be 70% that of 5-HT in a cytosensor cell-based assay compared with 84% for that of sumatriptan. PNU-142633 was equally effective as sumatriptan and a half-log more potent than sumatriptan in preventing plasma protein extravasation induced by electrical stimulation of the trigeminal ganglion. Like sumatriptan, PNU-142633 reduced the increase in cat nucleus trigeminal caudalis blood flow elicited by electrical stimulation of the trigeminal ganglion compared with the vehicle control. The direct vasoconstrictor potential of PNU-142633 was evaluated in vascular beds. Sumatriptan increased vascular resistance in carotid, meningeal and coronary arteries while PNU-142633 failed to alter resistance in these vascular beds. These data are discussed in relation to the clinical findings of PNU-142633 in a phase II acute migraine study. PMID:12485205

McCall, R B; Huff, R; Chio, C L; TenBrink, R; Bergh, C L; Ennis, M D; Ghazal, N B; Hoffman, R L; Meisheri, K; Higdon, N R; Hall, E

2002-12-01

243

Universal hand-held three-dimensional optoacoustic imaging probe for deep tissue human angiography and functional preclinical studies in real time.  

PubMed

The exclusive combination of high optical contrast and excellent spatial resolution makes optoacoustics (photoacoustics) ideal for simultaneously attaining anatomical, functional and molecular contrast in deep optically opaque tissues. While enormous potential has been recently demonstrated in the application of optoacoustics for small animal research, vast efforts have also been undertaken in translating this imaging technology into clinical practice. We present here a newly developed optoacoustic tomography approach capable of delivering high resolution and spectrally enriched volumetric images of tissue morphology and function in real time. A detailed description of the experimental protocol for operating with the imaging system in both hand-held and stationary modes is provided and showcased for different potential scenarios involving functional and molecular studies in murine models and humans. The possibility for real time visualization in three dimensions along with the versatile handheld design of the imaging probe make the newly developed approach unique among the pantheon of imaging modalities used in today's preclinical research and clinical practice. PMID:25408083

Deán-Ben, Xosé; Fehm, Thomas Felix; Razansky, Daniel

2014-01-01

244

The ?2?1 binding domain of chondroadherin inhibits breast cancer-induced bone metastases and impairs primary tumour growth: A preclinical study.  

PubMed

cyclicCHAD is a peptide representing the ?2?1 integrin binding sequence of the matrix protein chondroadherin (CHAD), which in our hands proved effective at counteracting bone loss in ovariectomised mice by inhibiting osteoclastogenesis. Given that bone metastases are characterised by exacerbated osteoclast activity as well, we tested this therapy in mice intracardiacally injected with the osteotropic human breast cancer cell line MDA-MB-231. Treatment with cyclicCHAD significantly decreased cachexia and incidence of bone metastases, and induced a trend of reduction of visceral metastasis volume, while in orthotopically injected mice cyclicCHAD reduced tumour volume. In vitro studies showed its ability to impair tumour cell motility and invasion, suggesting a direct effect not only on osteoclasts but also on the tumour cell phenotype. Interestingly, when administered together with a suboptimal, poorly effective, dose of doxorubicin (DXR), cyclicCHAD improved survival and reduced visceral metastases volume to a level similar to that of the optimal dose of DXR alone. Taken together, these preclinical data suggest that cyclicCHAD is a new inhibitor of bone metastases, with an appreciable direct effect also on tumour growth and a synergistic activity in combination with low dose chemotherapy, underscoring an important translational impact. PMID:25529009

Rucci, Nadia; Capulli, Mattia; Olstad, Ole K; Önnerfjord, Patrik; Tillgren, Viveka; Gautvik, Kaare M; Heinegård, Dick; Teti, Anna

2015-03-01

245

Autofluorescence imaging device for real-time detection and tracking of pathogenic bacteria in a mouse skin wound model: preclinical feasibility studies  

NASA Astrophysics Data System (ADS)

Bacterial infection significantly impedes wound healing. Clinical diagnosis of wound infections is subjective and suboptimal, in part because bacteria are invisible to the naked eye during clinical examination. Moreover, bacterial infection can be present in asymptomatic patients, leading to missed opportunities for diagnosis and treatment. We developed a prototype handheld autofluorescence (AF) imaging device (Portable Real-time Optical Detection, Identification and Guidance for Intervention-PRODIGI) to noninvasively visualize and measure bacterial load in wounds in real time. We conducted preclinical pilot studies in an established nude mouse skin wound model inoculated with bioluminescent Staphylococcus aureus bacteria. We tested the feasibility of longitudinal AF imaging for in vivo visualization of bacterial load in skin wounds, validated by bioluminescence imaging. We showed that bacteria (S. aureus), occult to standard examination, can be visualized in wounds using PRODIGI. We also detected quantitative changes in wound bacterial load over time based on the antibiotic treatment and the correlation of bacterial AF intensity with bacterial load. AF imaging of wounds offers a safe, noninvasive method for visualizing the presence, location, and extent of bacteria as well as measuring relative changes in bacterial load in wounds in real time.

Wu, Yichao Charlie; Kulbatski, Iris; Medeiros, Philip J.; Maeda, Azusa; Bu, Jiachuan; Xu, Lizhen; Chen, Yonghong; DaCosta, Ralph S.

2014-08-01

246

Preclinical studies with the anti-CD19-saporin immunotoxin BU12-SAPORIN for the treatment of human-B-cell tumours.  

PubMed Central

The immunotoxin BU12-SAPORIN was constructed by covalently coupling the single-chain ribosome-inactivating protein saporin to the anti-CD19 monoclonal antibody BU12 via a disulphide linker using the heterobifunctional reagent SPDP. The immunoreactivity and specificity of BU12-SAPORIN was identical to that of unmodified native BU12 antibody. BU12-SAPORIN was selectively cytotoxic in vitro in a dose-dependent manner for the CD19+ human common acute lymphoblastic leukaemia (cALL) cell line NALM-6 but exhibited no toxicity for the CD19- T-cell acute lymphoblastic leukaemia (T-ALL) cell line HSB-2. The survival of severe combined immunodeficient (SCID) mice with disseminated NALM-6 leukaemia was significantly prolonged compared with sham-treated control animals by a course of therapy with BU12-SAPORIN but not with the irrelevant anti-CD7 immunotoxin HB2-SAPORIN. BU12-SAPORIN had no therapeutic effect in SCID mice with disseminated CD19- HSB-2 leukaemia. These preclinical studies have clearly demonstrated the selective cytotoxicity of BU12-SAPORIN for CD19+ target cells both in vitro and in vivo. This, taken together with the lack of expression of the CD19 molecule by any normal life-sustaining tissue and its ubiquitous and homogeneous expression by the majority of cALL and B-NHL cells, provides the rationale for undertaking a phase I trial of systemic therapy with BU12-SAPORIN. Images Figure 1 PMID:8519647

Flavell, D. J.; Flavell, S. U.; Boehm, D. A.; Emery, L.; Noss, A.; Ling, N. R.; Richardson, P. R.; Hardie, D.; Wright, D. H.

1995-01-01

247

Preclinical evaluation of HIV eradication strategies in the simian immunodeficiency virus-infected rhesus macaque: a pilot study testing inhibition of indoleamine 2,3-dioxygenase.  

PubMed

Even in the setting of maximally suppressive antiretroviral therapy (ART), HIV persists indefinitely. Several mechanisms might contribute to this persistence, including chronic inflammation and immune dysfunction. In this study, we have explored a preclinical model for the evaluation of potential interventions that might serve to eradicate or to minimize the level of persistent virus. Given data that metabolic products of the inducible enzyme indoleamine 2,3-dioxygeanse (IDO) might foster inflammation and viral persistence, chronically simian immunodeficiency virus (SIV)-infected, ART-treated rhesus macaques were treated with the IDO inhibitor 1-methyl tryptophan (1mT). Orally administered 1mT achieved targeted plasma levels, but did not impact tryptophan metabolism or decrease viral RNA or DNA in plasma or in intestinal tissues beyond levels achieved by ART alone. Animals treated with 1mT showed no difference in the levels of T cell activation or differentiation, or in the kinetics or magnitude of viral rebound following cessation of ART. Notwithstanding these negative results, our observations suggest that the chronically SIV-infected rhesus macaque on suppressive ART can serve as a tractable model in which to test and to prioritize the selection of other potential interventions designed to eradicate HIV in vivo. In addition, this model might be used to optimize the route and dose by which such interventions are administered and the methods by which their effects are monitored. PMID:22924680

Dunham, Richard M; Gordon, Shari N; Vaccari, Monica; Piatak, Michael; Huang, Yong; Deeks, Steven G; Lifson, Jeffrey; Franchini, Genoveffa; McCune, Joseph M

2013-02-01

248

Preclinical Evaluation of HIV Eradication Strategies in the Simian Immunodeficiency Virus-Infected Rhesus Macaque: A Pilot Study Testing Inhibition of Indoleamine 2,3-Dioxygenase  

PubMed Central

Abstract Even in the setting of maximally suppressive antiretroviral therapy (ART), HIV persists indefinitely. Several mechanisms might contribute to this persistence, including chronic inflammation and immune dysfunction. In this study, we have explored a preclinical model for the evaluation of potential interventions that might serve to eradicate or to minimize the level of persistent virus. Given data that metabolic products of the inducible enzyme indoleamine 2,3-dioxygeanse (IDO) might foster inflammation and viral persistence, chronically simian immunodeficiency virus (SIV)-infected, ART-treated rhesus macaques were treated with the IDO inhibitor 1-methyl tryptophan (1mT). Orally administered 1mT achieved targeted plasma levels, but did not impact tryptophan metabolism or decrease viral RNA or DNA in plasma or in intestinal tissues beyond levels achieved by ART alone. Animals treated with 1mT showed no difference in the levels of T cell activation or differentiation, or in the kinetics or magnitude of viral rebound following cessation of ART. Notwithstanding these negative results, our observations suggest that the chronically SIV-infected rhesus macaque on suppressive ART can serve as a tractable model in which to test and to prioritize the selection of other potential interventions designed to eradicate HIV in vivo. In addition, this model might be used to optimize the route and dose by which such interventions are administered and the methods by which their effects are monitored. PMID:22924680

Dunham, Richard M.; Gordon, Shari N.; Vaccari, Monica; Piatak, Michael; Huang, Yong; Deeks, Steven G.; Lifson, Jeffrey; Franchini, Genoveffa

2013-01-01

249

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

PubMed

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. PMID:25442936

Steward, Oswald; Balice-Gordon, Rita

2014-11-01

250

Science teaching self-efficacy in a primary school: A case study  

NASA Astrophysics Data System (ADS)

Bandura's theory of self-efficacy predicts that teachers with high, self-efficacy should persist longer, provide a greater academic focus in child-centred classrooms and exhibit different types of feedback than teachers who have lower self-efficacy. This paper reports on the science teaching self-efficacy in a group of teachers at a state primary school. The research was conducted in two stages using firstly the Science Teaching Efficacy Beliefs Instrument (STEBI-A) to identify cases, and secondly, a semistructured interview coupled with classroom observations. Thirty seven teaching staff were surveyed with the STEBI-A instrument. The five highest and five lowest scoring teachers on the personal science teaching self-efficacy subscale of the STEBI-A were interviewed. The analysis of interviews and observations indicated that teachers with high personal science teaching self-efficacy have had a long interest in science and a relatively strong background of formal science studies with opportunities for exploring out of school activities. Although they may have experienced negative science experiences in their own schooling other ameliorating factors existed which maintained their interest. Their instructional strategies in science lessons were more child-centred than those reported by teachers with lower personal science teaching self-efficacy. The implications of the results for the inservice training of teachers are discussed.

de Laat, Jenny; Watters, James J.

1995-12-01

251

Evaluation of diethylnitrosamine- or hepatitis B virus X gene-induced hepatocellular carcinoma with 18F-FDG PET/CT: A preclinical study.  

PubMed

The aim of this study was to evaluate whether the development of hepatocellular carcinoma (HCC) in murine models resembles tumor progression in humans, using non?invasive molecular imaging methods. Murine HCC models were generated by treating mice with diethylnitrosamine (DEN) or by the transgenic expression of hepatitis B virus X (HBx) protein (HBx-Tg model). Tumor development was detected using 18F-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) and magnetic resonance imaging (MRI). The histopathological changes and expression of glucose transporter 1 (Glut1) and hexokinase 2 (HK2) were evaluated using hematoxylin and eosin and immunohistochemical staining, respectively. Tumor lesions as small as 1 mm in diameter were detected by MRI. Tumor development was monitored using 18F-FDG PET/CT at 6.5?10 months after DEN treatment or 11?20 months after birth of the HBx-Tg model mice. A correlation study between the 18F-FDG uptake levels and expression levels of HK2 and Glut1 in developed HCC showed a high 18F-FDG uptake in poorly differentiated HCCs that expressed high levels of HK2, in contrast to that in well-differentiated tumors. The progression of primary HCCs resembling human HCC in murine models was detected and monitored by 18F-FDG PET/CT. The correlation between tumor size and SUVmax was verified in the two HCC models. To the best of our knowledge, this is the first study to demonstrate that in vivo 18F-FDG uptake varies in HCCs according to differentiation grade in a preclinical study. PMID:25371060

Park, Ju Hui; Kang, Joo Hyun; Lee, Yong Jin; Kim, Kwang Il; Lee, Tae Sup; Kim, Kyeong Min; Park, Ji Ae; Ko, Yin Ohk; Yu, Dae-Yeul; Nahm, Sang-Soep; Jeon, Tae Joo; Park, Young-Seo; Lim, Sang Moo

2015-01-01

252

University students' Internet attitudes and Internet self-efficacy: a study at three universities in Taiwan.  

PubMed

This study was conducted to explore university students' attitudes and self-efficacy toward the Internet. Moreover, the relationships between their attitudes and self-efficacy toward the Internet were also investigated. The sample of this study included 1,313 students, coming from three universities in Taiwan. It was found that male students expressed significantly more positive attitudes than females on their "perceived control" of the Internet. The male students also revealed better Internet self-efficacy than their female counterparts. Moreover, students having more on-line hours per week, in general, displayed more positive Internet attitudes and Internet self-efficacy. In addition, students' grade level also played an important role in their Internet attitudes; graduate students tended to possess more positive Internet attitudes. More importantly, students' Internet attitudes were highly correlated with their Internet self-efficacy. The results in this study seemed to reveal that students' attitudes toward the Internet could be viewed as one of the important indicators for predicting their Internet self-efficacy. It is also suggested that some training programs or courses may be helpful in improving university students' attitudes and self-efficacy toward the Internet. PMID:16901248

Wu, Ying-Tien; Tsai, Chin-Chung

2006-08-01

253

21 CFR 201.200 - Disclosure of drug efficacy study evaluations in labeling and advertising.  

21 Food and Drugs 4 2014-04-01 2014-04-01 false Disclosure of drug efficacy study evaluations in labeling and advertising. 201.200 Section 201.200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT...

2014-04-01

254

21 CFR 201.200 - Disclosure of drug efficacy study evaluations in labeling and advertising.  

Code of Federal Regulations, 2013 CFR

21 Food and Drugs 4 2013-04-01 2013-04-01 false Disclosure of drug efficacy study evaluations in labeling and advertising. 201.200 Section 201.200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT...

2013-04-01

255

21 CFR 201.200 - Disclosure of drug efficacy study evaluations in labeling and advertising.  

Code of Federal Regulations, 2012 CFR

21 Food and Drugs 4 2012-04-01 2012-04-01 false Disclosure of drug efficacy study evaluations in labeling and advertising. 201.200 Section 201.200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT...

2012-04-01

256

Regulatory considerations for preclinical development of anticancer drugs  

Microsoft Academic Search

The entry of new anticancer treatments into phase I clinical trials is ordinarily based on relatively modest preclinical\\u000a data. This report defines the battery of preclinical tests important for assessing safety under an Investigational New Drug\\u000a application (IND) and outlines a basis for extrapolating starting doses of investigational anticancer drugs in phase I clinical\\u000a trials from animal toxicity studies. Types

Joseph J. DeGeorge; Chang-Ho Ahn; Paul A. Andrews; Margaret E. Brower; Diana W. Giorgio; M. Anwar Goheer; Doo Y. Lee-Ham; W. David McGuinn; Wendelyn Schmidt; C. Joseph Sun; Satish C. Tripathi

1997-01-01

257

An Empirical Research Study of the Efficacy of Two Plagiarism-Detection Applications  

Microsoft Academic Search

This article describes a study of the two most popular plagiarism-detection software platforms available on today's market—Turnitin (http:\\/\\/www.turnitin.com\\/static\\/index.html) and SafeAssign (http:\\/\\/www.safeassign.com\\/). After a brief discussion of plagiarism's relevance to librarians, the authors examine plagiarism-detection methodology and conduct a review of the current literature regarding plagiarism-detection efficacy. To evaluate detection efficacy for Turnitin and SafeAssign, the authors constructed a brief study

Jacob D. Hill; Elaine Fetyko Page

2009-01-01

258

Teacher efficacy: A comparative study of Hong Kong and Shanghai Primary in-service teachers  

Microsoft Academic Search

Teachers beliefs about their ability to affect students’ performance is an important part of professionalism. This study compared\\u000a 725 Hong Kong and 575 Shanghai primary in-service teachers on their teacher efficacy. Two Chinese versions of the 12-item\\u000a Teachers’ Sense of Efficacy Scale were used in this study since some wordings of the Hong Kong version of the Scale (HK-TSE)\\u000a were

Hoi Yan Cheung

2008-01-01

259

Fibrillar Amyloid Correlates of Preclinical Cognitive Decline  

PubMed Central

Background It is not known whether preclinical cognitive decline is associated with fibrillar ?-amyloid (A?) deposition irrespective of Apolipoprotein E (APOE) ?4 status. Methods From a prospective observational study of 623 cognitively normal individuals, we identified all subjects who showed preclinical decline of at least 2 standard deviations beyond the decline of the entire group in memory or executive function. Fourteen decliners were matched by APOE ?4 gene dose, age, sex, and education with 14 nondecliners. Dynamic Pittsburgh compound B (PiB) positron emission tomography (PET) scans, the Logan method, statistical parametric mapping, and automatically labeled regions of interest were used to characterize and compare cerebral-to-cerebellar PiB distribution volume ratios (DVR), reflecting fibrillar A? burden. Results At P<.005 (uncorrected), decliners had significantly greater DVR’s in comparison to nondecliners. Conclusions Asymptomatic longitudinal neuropsychological decline is associated with subsequent increased fibrillar amyloid deposition, even when controlling for APOE ?4 genotype. PMID:23583233

Stonnington, Cynthia M.; Chen, Kewei; Lee, Wendy; Locke, Dona E.C.; Dueck, Amylou C.; Liu, Xiaofen; Roontiva, Auttawut; Fleisher, Adam S.; Caselli, Richard J.; Reiman, Eric M.

2013-01-01

260

A rapid and sensitive LC-MS/MS assay for the determination of berbamine in rat plasma with application to preclinical pharmacokinetic study.  

PubMed

Berbamine (BBM), a natural compound from Chinese herb Berberis amurensis, has recently received a great deal of attention due to its anti-leukemia activity. In this study, a rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of BBM in rat plasma was developed for the first time. Caffeine was used as an internal standard. Chromatographic separation was performed on an ODS column with gradient elution using methanol-1% formic acid as mobile phase at a flow rate of 0.3mL/min. Quantification was through tandem mass spectrometry with positive electrospray ionization (ESI) and multiple reaction monitoring (MRM) at m/z 305.2?566.3 and 195.1?138.0 for BBM and IS, respectively. The lower limit of quantification was 1ng/mL with a linear range of 1-1000ng/mL. The intra- and inter-day assay precision (RSD) ranged from 2.0-6.4% to 2.5-5.5%, respectively, and the intra- and inter-day assay accuracy (RE) was between -5.8-6.0% and -6.5-1.4%, respectively. The validated method was successfully applied to the preclinical pharmacokinetic studies of BBM in rats. The elimination half-lives (t1/2) were (472.4±66.1), (509.6±97.0) and (486.2±94.6) min after single intravenous administration of 2, 4 and 8mg/kg BBM, respectively. The area under the plasma concentration versus time curve (AUC0-24h) and initial plasma concentration (C0) were linearly related to dose. PMID:23660248

Liu, Qingwang; Wang, Junsong; Yang, Lei; Jia, Yuanwei; Kong, Lingyi

2013-06-15

261

In situ study of the impact of inter- and intra-reader variability on region of interest (ROI) analysis in preclinical molecular imaging  

PubMed Central

We estimated reader-dependent variability of region of interest (ROI) analysis and evaluated its impact on preclinical quantitative molecular imaging. To estimate reader variability, we used five independent image datasets acquired each using microPET and multispectral fluorescence imaging (MSFI). We also selected ten experienced researchers who utilize molecular imaging in the same environment that they typically perform their own studies. Nine investigators blinded to the data type completed the ROI analysis by drawing ROIs manually that delineate the tumor regions to the best of their knowledge and repeated the measurements three times, non-consecutively. Extracted mean intensities of voxels within each ROI are used to compute the coefficient of variation (CV) and characterize the inter- and intra-reader variability. The impact of variability was assessed through random samples iterated from normal distributions for control and experimental groups on hypothesis testing and computing statistical power by varying subject size, measured difference between groups and CV. The results indicate that inter-reader variability was 22.5% for microPET and 72.2% for MSFI. Additionally, mean intra-reader variability was 10.1% for microPET and 26.4% for MSFI. Repeated statistical testing showed that a total variability of CV < 50% may be needed to detect differences < 50% between experimental and control groups when six subjects (n = 6) or more are used and statistical power is adequate (80%). Surprisingly high variability has been observed mainly due to differences in the ROI placement and geometry drawn between readers, which may adversely affect statistical power and erroneously lead to negative study outcomes. PMID:23526701

Habte, Frezghi; Budhiraja, Shradha; Keren, Shay; Doyle, Timothy C; Levin, Craig S; Paik, David S

2013-01-01

262

Abstract--A small, hermetic, wirelessly-controlled retinal prosthesis was developed for pre-clinical studies in Yucatan  

E-print Network

-clinical studies in Yucatan mini-pigs. The device was implanted on the outside of the eye in the orbit, Santa Barbara, CA 93106; J. Chen and J. F. Rizzo are with the Massachusetts Eye and Ear Infirmary inserted into the subjects' eyes, resting on or just above the epi-retinal surface. An external stimulator

Kelly, Shawn K.

263

Evaluation of Wound-Healing Potential of Pisonia grandis R.Br: A Preclinical Study in Wistar Rats  

Microsoft Academic Search

Pisonia grandis R.Br (family: Nyctaginaceae) is a herb claimed to be used for treatment of inflammation, wound healing, algesia, and ulcer. The present study was done to evaluate the wound-healing potential of methanolic extract of its leaves. Following preliminary photochemical evaluation, the extract was incorporated in simple ointment base and evaluated using 2 types of wound models in Wistar rats—excision

D. Prabu; M. Nappinnai; K. Ponnudurai; K. Prabhu

2008-01-01

264

[Preclinical studies for the use of the platelet function analyser PFA-100 with the collagen/ADP cartridge in dogs].  

PubMed

In this study, the following three aspects of platelet function analyser were investigated in dogs, using a collagen/ADP cartridge: precision, influence of the cartridge batch and of the sample storage time. Closure time and total volume of blood flow until closure of the capillary were measured. Based on several series of 5 repeated measurements mean coefficients of variation were 5% (3-6%; closure time) or 3% (1-5%; total volume). Neither closure time, nor total volume showed significant differences (p > 0.05) when comparing the results of 6 different batches of the collagen/ADP cartridge. Closure time (p = 0.0211, analysis of variance) and total volume (p = 0.0310) were significantly influenced by storage time, based on the sample material of 6 healthy dogs which was stored for 24 hours. Shortening of the closure time and decrease of the total volume observed in the time interval 1-2 hours after blood collection was followed by a significant prolongation of closure time and increase of the total volume (p < 0.05) starting 8 hours after blood collection. This study shows sufficient reproducibility which is not affected by reagent batch number. The results of the studies on storage indicated nearly identical recommendations for storage time before measurement of canine (0.5-2 hours) and human (0.5-3 hours) sample material. PMID:12073497

Mischke, R; Keidel, A

2002-05-01

265

Adjuvant anticholinesterase therapy for the management of epilepsy-induced memory deficit: a critical pre-clinical study.  

PubMed

Epilepsy is one of the major neurological disorders still awaiting safer drugs with improved antiepileptic effect and lesser side effects. Apart from epilepsy itself, AEDs also have been shown to induce cognitive impairment in patients with epilepsy. There are limited data for the treatment of this menace. As cholinergic approach has widely been practiced for the restoration of memory in various neurodegenerative disorders, this study was envisaged to evaluate add on effect of acetylcholinesterase inhibitor (tacrine) with phenytoin in pentylenetetrazole-kindling-induced learning and memory deficit in mice. In this study, mice were kindled using subconvulsive dose of pentylenetetrazole (35 mg/kg, i.p.; at interval of 48 ± 2 hr) and successfully kindled animals were divided into different groups and treated with vehicle, phenytoin and phenytoinin in combination with tacrine (0.3 mg/kg), atropine (1 mg/kg) and tacrine + atropine. Effect of different interventions on learning and memory was evaluated using elevated plus maze and passive shock avoidance on days 5, 10, 15 and 20. Phenytoin-treated kindled animals were associated with learning and memory deficit, while tacrine supplementation improved memory deficit with increased seizure severity score. Atropine treatment significantly reversed the protective effect of tacrine. Neurochemical findings also support the behavioural finding of the study. Our results suggest the use of anticholinesterases, with better seizure tolerance, for the management of cognitive impairment of epilepsy, as adjunct therapy. PMID:24890882

Mishra, Awanish; Goel, Rajesh Kumar

2014-12-01

266

Safety, Pharmacokinetic, and Efficacy Studies of Oral DB868 in a First Stage Vervet Monkey Model of Human African Trypanosomiasis  

PubMed Central

There are no oral drugs for human African trypanosomiasis (HAT, sleeping sickness). A successful oral drug would have the potential to reduce or eliminate the need for patient hospitalization, thus reducing healthcare costs of HAT. The development of oral medications is a key objective of the Consortium for Parasitic Drug Development (CPDD). In this study, we investigated the safety, pharmacokinetics, and efficacy of a new orally administered CPDD diamidine prodrug, 2,5-bis[5-(N-methoxyamidino)-2-pyridyl]furan (DB868; CPD-007-10), in the vervet monkey model of first stage HAT. DB868 was well tolerated at a dose up to 30 mg/kg/day for 10 days, a cumulative dose of 300 mg/kg. Mean plasma levels of biomarkers indicative of liver injury (alanine aminotransferase, aspartate aminotransferase) were not significantly altered by drug administration. In addition, no kidney-mediated alterations in creatinine and urea concentrations were detected. Pharmacokinetic analysis of plasma confirmed that DB868 was orally available and was converted to the active compound DB829 in both uninfected and infected monkeys. Treatment of infected monkeys with DB868 began 7 days post-infection. In the infected monkeys, DB829 attained a median Cmax (dosing regimen) that was 12-fold (3 mg/kg/day for 7 days), 15-fold (10 mg/kg/day for 7 days), and 31-fold (20 mg/kg/day for 5 days) greater than the IC50 (14 nmol/L) against T. b. rhodesiense STIB900. DB868 cured all infected monkeys, even at the lowest dose tested. In conclusion, oral DB868 cured monkeys with first stage HAT at a cumulative dose 14-fold lower than the maximum tolerated dose and should be considered a lead preclinical candidate in efforts to develop a safe, short course (5–7 days), oral regimen for first stage HAT. PMID:23755309

Thuita, John K.; Wolf, Kristina K.; Murilla, Grace A.; Liu, Qiang; Mutuku, James N.; Chen, Yao; Bridges, Arlene S.; Mdachi, Raymond E.; Ismail, Mohamed A.; Ching, Shelley; Boykin, David W.; Hall, James Edwin; Tidwell, Richard R.; Paine, Mary F.; Brun, Reto; Wang, Michael Zhuo

2013-01-01

267

Preclinical Study of Treatment Response in HCT-116 Cells and Xenografts with 1H-decoupled 31P MRS  

PubMed Central

The topoisomerase I inhibitor, irinotecan, and its active metabolite SN-38 have been shown to induce G2/M cell cycle arrest without significant cell death in human colon carcinoma cells (HCT-116). Subsequent treatment of these G2/M-arrested cells with the cyclin-dependent kinase inhibitor, flavopiridol, induced these cells to undergo apoptosis. The goal of this study was to develop a noninvasive metabolic biomarker for early tumor response and target inhibition of irinotecan followed by flavopiridol treatment in a longitudinal study. A total of eleven mice bearing HCT-116 xenografts were separated into two cohorts where one cohort was administered saline and the other treated with a sequential course of irinotecan followed by flavopiridol. Each mouse xenograft was longitudinally monitored with proton (1H)-decoupled phosphorus (31P) magnetic resonance spectroscopy (MRS) before and after treatment. A statistically significant decrease in phosphocholine (p = 0.0004) and inorganic phosphate (p = 0.0103) levels were observed in HCT-116 xenografts following treatment, which were evidenced within twenty-four hours of treatment completion. Also, a significant growth delay was found in treated xenografts. To discern the underlying mechanism for the treatment response of the xenografts, in vitro HCT-116 cell cultures were investigated with enzymatic assays, cell cycle analysis, and apoptotic assays. Flavopiridol had a direct effect on choline kinase as measured by a 67% reduction in the phosphorylation of choline to phosphocholine. Cells treated with SN-38 alone underwent 83±5% G2/M cell cycle arrest compared to untreated cells. In cells, flavopiridol alone induced 5±1% apoptosis while the sequential treatment (SN-38 then flavopiridol) resulted in 39±10% apoptosis. In vivo 1H-decoupled 31P MRS indirectly measures choline kinase activity. The decrease in phosphocholine may be a potential indicator of early tumor response to the sequential treatment of irinotecan followed by flavopiridol in noninvasive and/or longitudinal studies. PMID:21994185

Darpolor, Moses M.; Kennealey, Peter T.; Carl Le, H; Zakian, Kristen L.; Ackerstaff, Ellen; Rizwan, Asif; Chen, Jin-Hong; Sambol, Elliot B.; Schwartz, Gary K.; Singer, Samuel; Koutcher, Jason A.

2011-01-01

268

Bias analyses of preclinical and clinical d2 dopamine ligands: studies with immediate and complex signaling pathways.  

PubMed

G protein-coupled receptors (GPCRs) often activate multiple signaling pathways, and ligands may evoke functional responses through individual pathways. These unique responses provide opportunities for biased or functionally selective ligands to preferentially modulate one signaling pathway over another. Studies with several GPCRs have suggested that selective activation of signaling pathways downstream of a GPCR may lead to safer and more effective drug therapies. The dopamine D2 receptor (D2R) is one of the main drug targets in the therapies for Parkinson's disease and schizophrenia. Recent studies suggest that selective modulation of individual signaling pathways downstream of the D2R may lead to safer antipsychotic drugs. In the present study, immediate effectors of the D2R (i.e., G?i/o, G??, ?-arrestin recruitment) and more complex signaling pathways (i.e., extracellular signal-regulated kinase phosphorylation, heterologous sensitization, and dynamic mass redistribution) were examined in response to a series of D2R ligands. This was accomplished using Chinese hamster ovary cells stably expressing the human D2L dopamine receptor in the PathHunter ?-Arrestin GPCR Assay Platform. The use of a uniform cellular background was designed to eliminate potential confounds associated with cell-to-cell variability, including expression levels of receptor as well as other components of signal transduction, including G protein subunits. Several well characterized and clinically relevant D2R ligands were evaluated across each signaling pathway in this cellular model. The most commonly used methods to measure ligand bias were compared. Functional selectivity analyses were also used as tools to explore the relative contribution of immediate D2R effectors for the activation of more complex signaling pathways. PMID:25539635

Brust, Tarsis F; Hayes, Michael P; Roman, David L; Burris, Kevin D; Watts, Val J

2015-03-01

269

Development of Allogeneic NK Cell Adoptive Transfer Therapy in Metastatic Melanoma Patients: In Vitro Preclinical Optimization Studies  

PubMed Central

Natural killer (NK) cells have long been considered as potential agents for adoptive cell therapy for solid cancer patients. Until today most studies utilized autologous NK cells and yielded disappointing results. Here we analyze various modular strategies to employ allogeneic NK cells for adoptive cell transfer, including donor-recipient HLA-C mismatching, selective activation and induction of melanoma-recognizing lysis receptors, and co-administration of antibodies to elicit antibody-dependent cell cytotoxicity (ADCC). We show that NK cell activation and induction of the relevant lysis receptors, as well as co-administration of antibodies yield substantial anti-cancer effects, which are functionally superior to HLA-C mismatching. Combination of the various strategies yielded improved effects. In addition, we developed various clinically-compatible ex vivo expansion protocols that were optimized according to fold expansion, purity and expression of lysis receptors. The main advantages of employing allogeneic NK cells are accessibility, the ability to use a single donor for many patients, combination with various strategies associated with the mechanism of action, e.g. antibodies and specific activation, as well as donor selection according to HLA or CD16 genotypes. This study rationalizes a clinical trial that combines adoptive transfer of highly potent allogeneic NK cells and antibody therapy. PMID:23483943

Besser, Michal J.; Shoham, Tsipi; Harari-Steinberg, Orit; Zabari, Naama; Ortenberg, Rona; Yakirevitch, Arkadi; Nagler, Arnon; Loewenthal, Ron; Schachter, Jacob; Markel, Gal

2013-01-01

270

Development of allogeneic NK cell adoptive transfer therapy in metastatic melanoma patients: in vitro preclinical optimization studies.  

PubMed

Natural killer (NK) cells have long been considered as potential agents for adoptive cell therapy for solid cancer patients. Until today most studies utilized autologous NK cells and yielded disappointing results. Here we analyze various modular strategies to employ allogeneic NK cells for adoptive cell transfer, including donor-recipient HLA-C mismatching, selective activation and induction of melanoma-recognizing lysis receptors, and co-administration of antibodies to elicit antibody-dependent cell cytotoxicity (ADCC). We show that NK cell activation and induction of the relevant lysis receptors, as well as co-administration of antibodies yield substantial anti-cancer effects, which are functionally superior to HLA-C mismatching. Combination of the various strategies yielded improved effects. In addition, we developed various clinically-compatible ex vivo expansion protocols that were optimized according to fold expansion, purity and expression of lysis receptors. The main advantages of employing allogeneic NK cells are accessibility, the ability to use a single donor for many patients, combination with various strategies associated with the mechanism of action, e.g. antibodies and specific activation, as well as donor selection according to HLA or CD16 genotypes. This study rationalizes a clinical trial that combines adoptive transfer of highly potent allogeneic NK cells and antibody therapy. PMID:23483943

Besser, Michal J; Shoham, Tsipi; Harari-Steinberg, Orit; Zabari, Naama; Ortenberg, Rona; Yakirevitch, Arkadi; Nagler, Arnon; Loewenthal, Ron; Schachter, Jacob; Markel, Gal

2013-01-01

271

Validated LC-MS/MS assay for the determination of felbinac: Application to a preclinical pharmacokinetics study of felbinac trometamol injection in rat.  

PubMed

A rapid and sensitive analytical method based on high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of felbinac in rat plasma, bile, urine, feces and tissue. Sample preparation involved liquid-liquid extraction with ethyl ether-dichloromethane (60:40, v/v). Chromatography of felbinac and the internal standard probenecid was performed within 2min on a Venusil MP C(18) column (100mmx4.6mm i.d., 5microm) with a mobile phase consisting of acetonitrile-5mM ammonium acetate containing 0.1% formic acid (pH 3.0) (80:20, v/v) at a flow rate of 1.2ml/min. Detection by electrospray negative ionization mass spectrometry and multiple-reaction monitoring of the transitions of felbinac at m/z 211.1-->167.0 and of probenecid at m/z 283.9-->239.9 was linear over the concentration range 5-5000ng/ml with a lower limit of quantitation of 5ng/ml using a sample volume of only 50microl. Intra- and inter-day precisions (as relative standard deviation, R.S.D.) were < or =7.3% and < or =6.4%, respectively, and accuracy (as relative error, R.E.) was in the range -2.1 to 7.4%. Recoveries and matrix effects were satisfactory in all the biological matrices examined. The method was applied to a preclinical pharmacokinetic study in rat involving a single intravenous injection of felbinac trometamol. PMID:19376665

Zhang, Chao; Wang, Lu; Yang, Wei; Wang, Xisha; Fawcett, J Paul; Sun, Yantong; Gu, Jingkai

2009-08-15

272

Quantification of pinosylvin in rat plasma by liquid chromatography-tandem mass spectrometry: application to a pre-clinical pharmacokinetic study.  

PubMed

Pinosylvin (trans-3,5-dihydroxystilbene), a naturally occurring analogue of resveratrol (trans-3,5,4'-trihydoxystilbene), exhibited various beneficial pharmacological activities in pre-clinical studies. To further probe its potential medicinal application, a sensitive liquid chromatography-tandem mass spectrometry method (LC-MS/MS) was developed and validated for the quantification of pinosylvin in rat plasma. A simple protein precipitation procedure was used for plasma cleanup before analysis by LC-MS/MS with electrospray ionisation and multiple reaction monitoring in its negative ion mode. This LC-MS/MS method demonstrated good selectivity, accuracy (intra- and inter-day analytical recovery within 100±7.7%), precision (intra- and inter-day coefficient of variation<12.0%) and sensitivity (lower limit of detection=1.0ng/mL), with excellent linearity (R(2)>0.99) over the range of 1-1000ng/mL. The pharmacokinetic profiles of pinosylvin were subsequently assessed in Sprague-Dawley rats. Following intravenous administration (5 or 10mg/kg), plasma levels of pinosylvin declined rapidly with a short half-life (t1/2<10min). Upon oral administration at 15mg/kg, pinosylvin could not be quantified in plasma (<1ng/mL) while dose-escalation to 50mg/kg led to a low and erratic plasma exposure with very poor estimated oral bioavailability (F<1%). The short half-life and limited systemic exposure of pinosylvin prompt caution in its therapeutic application and it warrants exploration in developing pinosylvin pro-drug. PMID:23777612

Yeo, Samuel Chao Ming; Luo, Wenxia; Wu, Jinzhu; Ho, Paul C; Lin, Hai-Shu

2013-07-15

273

Function and redox state of peritoneal leukocytes as preclinical and prodromic markers in a longitudinal study of triple-transgenic mice for Alzheimer's disease.  

PubMed

The aging process involves the impairment of the immune system (immunosenescence), based on the imbalance of the redox status, as occurs in neurodegenerative diseases such as Alzheimer's disease (AD). Since in AD there is a systemic disorder, we aimed to assess longitudinally, from before the onset until the complete establishment of AD, cell populations, several functions, and oxidative stress parameters in peritoneal leukocytes of triple transgenic mice for AD (3xTgAD). These animals mimic the human AD pathophysiology. The results indicate a premature immunosenescence in 3xTgAD at 4 months of age, when the immunoreactivity against intracellular amyloid-? fibrils appears. Thus, decreases in functions such as chemotaxis, phagocytosis, and lymphoproliferation, as well as a lower reduced glutathione content and higher xanthine oxidase activity, appear in leukocytes. Moreover, NK percentage and cytotoxic activity, CD25+ B and naïve CD8 T cells percentage, GSSG/GSH ratio, and GSH content were already changed before the onset of AD, at the age of 2 months. Furthermore, the changes in some parameters such as CD5+ B1 cells, phagocytosis, lymphoproliferation, and xanthine oxidase activity continue at 15 months of age, when AD pathophysiology is completely established. Because the immune system parameters studied are markers of health and longevity, the premature immunosenescence could explain the shorter life span shown by 3xTgAD observed in the present work. These results suggest that peripheral immune cell functions and their oxidative stress status could be good early peripheral markers of the preclinical and prodromal stages and progression of AD. PMID:25079793

Maté, Ianire; Cruces, Julia; Giménez-Llort, Lydia; De la Fuente, Mónica

2015-01-01

274

[111In-DOTA]Somatostatin-14 analogs as potential pansomatostatin-like radiotracers - first results of a preclinical study  

PubMed Central

Background In this study, we report on the synthesis, radiolabeling, and biological evaluation of two new somatostatin-14 (SS14) analogs, modified with the universal chelator DOTA. We were interested to investigate if and to what extent such radiotracer prototypes may be useful for targeting sst1-5-expressing tumors in man but, most importantly, to outline potential drawbacks and benefits associated with their use. Methods AT1S and AT2S (DOTA-Ala1-Gly2-c[Cys3-Lys4-Asn5-Phe6-Phe7-Trp8/DTrp8-Lys9-Thr10-Phe11-Thr12-Ser13-Cys14-OH], respectively) were synthesized on the solid support and labeled with 111In. The sst1-5 affinity profile of AT1S/AT2S was determined by receptor autoradiography using [Leu8,dTrp22,125I-Tyr25]SS28 as radioligand. The ability of AT2S to stimulate sst2 or sst3 internalization was qualitatively analyzed by an immunofluorescence-based internalization assay using hsst2- or hsst3-expressing HEK293 cells. Furthermore, the internalization of the radioligands [111In]AT1S and [111In]AT2S was studied at 37?°C in AR4-2J cells endogenously expressing sst2. The in vivo stability of [111In]AT1S and [111In]AT2S was tested by high-performance liquid chromatography analysis of mouse blood collected 5?min after radioligand injection, and biodistribution was studied in normal mice. Selectively for [111In]AT2S, biodistribution was further studied in SCID mice bearing AR4-2J, HEK293-hsst2A+, -hsst3+ or -hsst5+ tumors. Results The new SS14-derived analogs were obtained by solid phase peptide synthesis and were easily labeled with 111In. Both SS14 conjugates, AT1S, and its DTrp8 counterpart, AT2S, showed a pansomatostatin affinity profile with the respective hsst1-5 IC50 values in the lower nanomolar range. In addition, AT2S behaved as an agonist for sst2 and sst3 since it stimulated receptor internalization. The 111In radioligands effectively and specifically internalized into rsst2A-expressing AR4-2J cells with [111In]AT2S internalizing faster than [111In]AT1S. Ex vivo mouse blood analysis revealed a rapid degradation of both radiopeptides in the bloodstream with the DTrp8 analog showing higher stability. Biodistribution results in healthy mice were consistent with these findings with only [111In]AT2S showing specific uptake in the sst2-rich pancreas. Biodistribution of [111In]AT2S in tumor-bearing mice revealed receptor-mediated uptake in the AR4-2J (1.82?±?0.36 %ID/g - block 0.21?±?0.17 %ID/g at 4?h post injection (pi)), the HEK293-hsst2A+ (1.49?±?0.2 %ID/g - block 0.27?±?0.20 %ID/g at 4?h pi), the HEK293-hsst3+ (1.24?±?0.27 %ID/g - block 0.32?±?0.06 %ID/g at 4?h pi), and the HEK293-hsst5+ tumors (0.41?±?0.12 %ID/g - block 0.22?±?0.006 %ID/g at 4?h pi). Radioactivity washed out from blood and background tissues via the kidneys. Conclusions This study has revealed that the native SS14 structure can indeed serve as a motif for the development of promising pansomatostatin-like radiotracers. Further peptide stabilization is required to increase in vivo stability and, consequently, to enhance in vivo delivery and tumor targeting. PMID:22682002

2012-01-01

275

Pleiotropic effects of the rho-kinase inhibitor fasudil after subarachnoid hemorrhage: a review of preclinical and clinical studies.  

PubMed

There is growing evidence that Rho-kinase contributes to cardiovascular disease, which has made Rho-kinase a target for the treatment of human diseases. To date, the only Rho-kinase inhibitor employed clinically in humans is fasudil, which has been used for the prevention of cerebral vasospasm and subsequent ischemic injury after surgery for subarachnoid hemorrhage (SAH). A number of pathological processes, in particular hemodynamic dysfunctions and inflammatory reactions, are thought to be related in the pathogenesis of delayed cerebral vasospasm and subsequent ischemic injury after SAH. This review focuses on fasudil's pleiotropic therapeutic effects: amelioration of hemodynamic dysfunction and inflammation, and discusses in detail the clinical studies on fasudil administered after the occurrence of SAH. PMID:24923440

Satoh, Shin-ichi; Ikegaki, Ichiro; Kawasaki, Koh; Asano, Toshio; Shibuya, Masato

2014-01-01

276

177Lu-EC0800 combined with the antifolate pemetrexed: preclinical pilot study of folate receptor targeted radionuclide tumor therapy.  

PubMed

Targeted radionuclide therapy has shown impressive results for the palliative treatment of several types of cancer diseases. The folate receptor has been identified as specifically associated with a variety of frequent tumor types. Therefore, it is an attractive target for the development of new radionuclide therapies using folate-based radioconjugates. Previously, we found that pemetrexed (PMX) has a favorable effect in reducing undesired renal uptake of radiofolates. Moreover, PMX also acts as a chemotherapeutic and radiosensitizing agent on tumors. Thus, the aim of our study was to investigate the combined application of PMX and the therapeutic radiofolate (177)Lu-EC0800. Determination of the combination index (CI) revealed a synergistic inhibitory effect of (177)Lu-EC0800 and PMX on the viability of folate receptor-positive cervical (KB) and ovarian (IGROV-1) cancer cells in vitro (CI < 0.8). In an in vivo study, tumor-bearing mice were treated with (177)Lu-EC0800 (20 MBq) and a subtherapeutic (0.4 mg) or therapeutic amount (1.6 mg) of PMX. Application of (177)Lu-EC0800 with PMXther resulted in a two- to four-fold enhanced tumor growth delay and a prolonged survival of KB and IGROV-1 tumor-bearing mice, as compared to the combination with PMXsubther or untreated control mice. PMXsubther protected the kidneys from undesired side effects of (177)Lu-EC0800 (20 MBq) by reducing the absorbed radiation dose. Intact kidney function was shown by determination of plasma parameters and quantitative single-photon emission computed tomography using (99m)Tc-DMSA. Our results confirmed the anticipated dual role of PMX. Its unique features resulted in an improved antitumor effect of folate-based radionuclide therapy and prevented undesired radio-nephrotoxicity. PMID:24030631

Reber, Josefine; Haller, Stephanie; Leamon, Christopher P; Müller, Cristina

2013-11-01

277

Preclinical assessment of infant formula.  

PubMed

Infant formulas are the sole or predominant source of nutrition for many infants and are fed during a sensitive period of development and may therefore have short- and long-term consequences for infant health. Preclinical safety assessment therefore needs to include both short-term and long-term studies in animals. It is recommended that procedures are instituted by which experts may serve as independent scientists for companies developing novel products, without having their integrity compromised, and later serve the legislative institutions. A two-level assessment approach to determine the potential toxicity of a novel ingredient, its metabolites, and their effects in the matrix on developing organ systems has been suggested by IOM. This appears reasonable, as novel ingredients can be of different levels of concern. The use of modern methods in genomics and proteomics should be considered in these evaluation processes as well as novel methods to evaluate outcomes, including metabolomics and molecular techniques to assess the microbiome. PMID:22699767

Lönnerdal, Bo

2012-01-01

278

Enhanced killing of primary ovarian cancer by retargeting autologous cytokine-induced killer cells with bispecific antibodies: a preclinical study.  

PubMed

Cytokine-induced killer (CIK) cells are ex vivo activated and expanded CD8+ natural killer T cells that have been shown to have antitumor activity. This is the first study exploring cell killing of primary ovarian carcinoma cells with and without bispecific antibodies. Primary cancer cells and autologous CIK cells were collected from women with epithelial ovarian cancer. Bispecific antibodies against cancer antigen-125 (BSAbxCA125) and Her2 (BSAbxHer2) were developed using chemical heteroconjugation. On fluorescence-activated cell sorting analysis, the expansion of CIK cells resulted in a significant increase of CD3+CD8+ and CD3+CD56+ T cells. With enhancement by bispecific antibodies, the mean percent lysis in a 51Cr release assay of fresh ovarian cancer cells exposed to autologous CIK cells increased from 21.7 +/- 0.3% to 89.4 +/- 2.1% at an E:T ratio of 100:1 (P < 0.001). Anti-NKG2D antibodies attenuated the CIK activity by 56.8% on primary cells (P < 0.001). In a xenograft severe combined immunodeficient mouse model, real-time tumor regression and progression was visualized using a noninvasive in vivo bioluminescence imaging system. Four hours after CIK cell injection, we were able to visualize CD8+NKG2D+ CIK cells infiltrating Her2-expressing cancer cells on fluorescence microscopy. Mice that underwent adoptive transfer of CIK cells redirected with BSAbxCA125 and BSAbxHer2 had significant reduction in tumor burden (P < 0.001 and P < 0.001) and improvement in survival (P = 0.05 and P = 0.006) versus those treated with CIK cells alone. Bispecific antibodies significantly enhanced the cytotoxicity of CIK cells in primary ovarian cancer cells and in our in vivo mouse model. The mechanism of cytolysis seems to be mediated in part by the NKG2D receptor. PMID:16551871

Chan, John K; Hamilton, Chad A; Cheung, Michael K; Karimi, Mobin; Baker, Jeanette; Gall, Jonathan M; Schulz, Stephan; Thorne, Steve H; Teng, Nelson N; Contag, Christopher H; Lum, Lawrence G; Negrin, Robert S

2006-03-15

279

From type 2 diabetes to antioxidant activity: a systematic review of the safety and efficacy of common and cassia cinnamon bark  

Microsoft Academic Search

Common (Cinnamomum verum, C. zeylanicum) and cassia (C. aromaticum) cinnamon have a long history of use as spices and flavouring agents. A number of pharmacological and clinical effects have been observed with their use. The objective of this study was to systematically review the scientific literature for preclinical and clinical evidence of safety, efficacy, and pharmacological activity of common and

Jean-Jacques Dugoua; Dugald Seely; Dan Perri; Kieran Cooley; Taryn Forelli; Edward Mills; Gideon Koren

2007-01-01

280

A Cross-Sectional Study of Engineering Students' Self-Efficacy by Gender, Ethnicity, Year, and Transfer Status  

ERIC Educational Resources Information Center

This is a cross-sectional study of 519 undergraduate engineering majors' self-efficacy beliefs at a large, research extensive, Midwestern university. Engineering self-efficacy is an individual's belief in his or her ability to successfully negotiate the academic hurdles of the engineering program. Engineering self-efficacy was obtained from four…

Concannon, James P.; Barrow, Lloyd H.

2009-01-01

281

Teachers' Sense of Self-Efficacy, English Proficiency, and Instructional Strategies: A Study of Nonnative EFL Teachers in Iran  

Microsoft Academic Search

This study examined the efficacy beliefs of nonnative English speaking (NNES) Iranian EFL teachers. EFL teachers' perceptions of their teaching efficacy in terms of personal capabilities to teach English as a Foreign Language (EFL) and their perceived English language proficiency level were examined. A modified version of the Teacher Sense of Efficacy Scale (Tschannen-Moran & Woolfolk Hoy, 2001) was used

Zohreh R. Eslami; Azizullah Fatahi

2008-01-01

282

Preclinical electrogastrography in experimental pigs.  

PubMed

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

Kv?tina, Jaroslav; Edakkanambeth Varayil, Jithinraj; Ali, Shahzad Marghoob; Kuneš, Martin; Bureš, Jan; Tachecí, Ilja; Rejchrt, Stanislav; Kopá?ová, Marcela

2010-06-01

283

Preclinical electrogastrography in experimental pigs  

PubMed Central

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

Kv?tina, Jaroslav; Varayil, Jithinraj Edakkanambeth; Ali, Shahzad Marghoob; Kuneš, Martin; Bureš, Jan; Tachecí, Ilja; Rejchrt, Stanislav; Kopá?ová, Marcela

2010-01-01

284

Preclinical pharmacology and toxicology study of Ad-hTERT-E1a-Apoptin, a novel dual cancer-specific oncolytic adenovirus.  

PubMed

Clinical studies have demonstrated that conditionally replicating adenovirus is safe. We constructed an oncolytic adenovirus, Ad-hTERT-E1a-Apoptin, using a cancer-specific promoter (human telomerase reverse transcriptase promoter, hTERTp) and a cancer cell-selective apoptosis-inducing gene (Apoptin). Ad-hTERT-E1a-Apoptin was proven effective both in vitro and in vivo in our previous study. In this study, the preclinical safety profiles of Ad-hTERT-E1a-Apoptin in animal models were investigated. At doses of 5.0×10(8), 2.5×10(9), and 1.25×10(10) viral particles (VP)/kg, Ad-hTERT-E1a-Apoptin had no adverse effects on mouse behavior, muscle cooperation, sedative effect, digestive system, and nervous systems, or on beagle cardiovascular and respiratory systems at 5.0×10(8), 2.5×10(9), and 1.25×10(10) VP/kg doses. In acute toxicity tests in mice, the maximum tolerated dose>5×10(10) VP/kg. There was no inflammation or ulceration at the injection sites within two weeks. In repeat-dose toxicological studies, the no observable adverse effect levels of Ad-hTERT-E1a-Apoptin in rats (1.25×10(10) VP/kg) and beagles (2.5×10(9) VP/kg) were 62.5- and 12.5-fold of the proposed clinical dose, respectively. The anti-virus antibody was produced in animal sera. Bone marrow examination revealed no histopathological changes. Guinea pigs sensitized by three repeated intraperitoneal injections of 1.35×10(10) VP/mL Ad-hTERT-E1a-Apoptin each and challenged by one intravenous injection of 1.67×10(8) VP/kg Ad-hTERT-E1a-Apoptin did not exhibit any sign of systemic anaphylaxis. Our data from different animal models suggest that Ad-hTERT-E1a-Apoptin is a safe anti-tumor therapeutic agent. PMID:25151223

Qi, Yanxin; Guo, Huanhuan; Hu, Ningning; He, Dongyun; Zhang, Shi; Chu, Yunjie; Huang, Yubin; Li, Xiao; Sun, LiLi; Jin, Ningyi

2014-10-15

285

[Study on immune efficacy of Newcastle disease chitosan microsphere vaccine].  

PubMed

Newcastle disease is an acute and highly contagious disease caused by Newcastle disease virus (NDV), one of which does great harms to the poultry industry. The most basic measure of controlling New Castle disease is to alid vaccine, now we usually use La Sota live vaccine and inactivated NDV vaccine, but these two vaccines both have more or less limitation. It can produce higher mucosal immunity titers by taking vaccine orally, meanwhile it can induce humoral and cell-mediated immune response and mucosal immunity strongly. Therefore, it becomes the focus of the research, which prepare new pattern vaccines taking orally. NDV chitosan microsphere vaccine was prepared using chitosan as capsule wall material, NDV as core material, glutaraldehyde as cross-linking material, and its even particle diameter was 5.83um, and its surface was smooth and glossy, no obviously pore space, yellow brown pykno-ball, and its safety and potency were evaluated. The SPF chickens were immunized with NDV chitosan microsphere vaccine, La Sota live vaccine and inactivated NDV vaccine respectively. To evaluate vaccine's immune efficacy, using MTT to measure lymphocytes proliferation in vitro, using HI to measure serum special IgG and using ELISA tests to detect mucosal sIgA titers. The results show that NDV chitosan microsphere vaccine was safe, could induce humoral and cell-mediated immune response and mucosal immunity strongly. The results of the potency tests conformed that the vaccine could produce good protective effect. PMID:17944374

Zhai, Rong-ling; Xu, Huai-ying; Wang, You-ling; Qin, Zhuo-ming; Jiang, Shi-jin

2007-08-01

286

Lost in translation: preclinical studies on 3,4-methylenedioxymethamphetamine provide information on mechanisms of action, but do not allow accurate prediction of adverse events in humans  

PubMed Central

3,4-Methylenedioxymethamphetamine (MDMA) induces both acute adverse effects and long-term neurotoxic loss of brain 5-HT neurones in laboratory animals. However, when choosing doses, most preclinical studies have paid little attention to the pharmacokinetics of the drug in humans or animals. The recreational use of MDMA and current clinical investigations of the drug for therapeutic purposes demand better translational pharmacology to allow accurate risk assessment of its ability to induce adverse events. Recent pharmacokinetic studies on MDMA in animals and humans are reviewed and indicate that the risks following MDMA ingestion should be re-evaluated. Acute behavioural and body temperature changes result from rapid MDMA-induced monoamine release, whereas long-term neurotoxicity is primarily caused by metabolites of the drug. Therefore acute physiological changes in humans are fairly accurately mimicked in animals by appropriate dosing, although allometric dosing calculations have little value. Long-term changes require MDMA to be metabolized in a similar manner in experimental animals and humans. However, the rate of metabolism of MDMA and its major metabolites is slower in humans than rats or monkeys, potentially allowing endogenous neuroprotective mechanisms to function in a species specific manner. Furthermore acute hyperthermia in humans probably limits the chance of recreational users ingesting sufficient MDMA to produce neurotoxicity, unlike in the rat. MDMA also inhibits the major enzyme responsible for its metabolism in humans thereby also assisting in preventing neurotoxicity. These observations question whether MDMA alone produces long-term 5-HT neurotoxicity in human brain, although when taken in combination with other recreational drugs it may induce neurotoxicity. LINKED ARTICLES This article is commented on by Parrott, pp. 1518–1520 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2012.01941.x and to view the the rebuttal by the authors (Green et al., pp. 1521–1522 of this issue) visit http://dx.doi.org/10.1111/j.1476-5381.2012.01940.x PMID:22188379

Green, AR; King, MV; Shortall, SE; Fone, KCF

2012-01-01

287

Advances in Preclinical SPECT Instrumentation  

PubMed Central

Preclinical SPECT imaging of rodents is both in demand and very demanding. The need for high spatial resolution in combination with good sensitivity has given rise to considerable innovation in the areas of detectors, collimation, acquisition geometry, and image reconstruction. Some of the developments described herein are beginning to carry over into clinical imaging as well. PMID:22586145

Peterson, Todd E.; Shokouhi, Sepideh

2012-01-01

288

Learning strategies and self-efficacy as predictors of academic performance: a preliminary study  

Microsoft Academic Search

Empirical research supports the idea that differences in academic performance among students are largely due to their different learning and study strategies. The strategies, in turn, affect the self-efficacy of the students. Two hundred university students were recruited to participate in this study by completing a revised Chinese version of the Learning and Study Strategies Inventory, on examining the extended

Michael C. W. Yip

2012-01-01

289

Assessing the Effects of Collaborative Professional Learning: Efficacy Shifts in a Three-Year Mathematics Study  

ERIC Educational Resources Information Center

Researchers examine the outcomes of professional collaborative inquiry in mathematics on teacher efficacy in a three-year study of teacher professional learning in Canada. The study applies a mixed methods approach involving over 200 teachers and 1000 students as well as case study sites in English and French. The collaborative inquiry-based…

Bruce, Catherine D.; Flynn, Tara

2012-01-01

290

Comparative study of the neurotrophic effects elicited by VEGF-B and GDNF in preclinical in vivo models of Parkinson’s disease  

PubMed Central

Vascular endothelial growth factor B (VEGF-B) has recently been shown to be a promising novel neuroprotective agent for several neurodegenerative conditions. In the current study we extended previous work on neuroprotective potential for Parkinson’s disease (PD) by testing an expanded dose range of VEGF-B (1 ?g and 10 ?g) and directly comparing both neuroprotective and neurorestorative effects of VEGF-B in progressive unilateral 6-hydroxydopamine (6-OHDA) PD models to a single dose of glial cell line-derived neurotrophic factor (GDNF, 10 ?g), that has been established by several groups as a standard in both preclinical PD models. In the amphetamine-induced rotational tests the treatment with 1 and 10 ?g VEGF-B resulted in significantly improved motor function of 6-OHDA-lesioned rats compared to vehicle-treated 6-OHDA-lesioned rats in the neuroprotection paradigm. Both doses of VEGF-B caused an increase in tyrosine hydroxylase (TH)-positive cell and fiber count in the substantia nigra (SN) and striatum in the neuroprotective experiment. The effect size was comparable to the effects seen with GDNF. In the neurorestoration paradigm, VEGF-B injection had no significant effect in either the behavioral or the immunohistochemical analyses, whereas GDNF injection significantly improved the amphetamine-induced rotational behavior and reduced TH-positive neuronal cell loss in the SN. We also present a strong positive correlation (p = 1.9 e-50) of the expression of VEGF-B with nuclear-encoded mitochondrial genes involved in fatty acid metabolism in rat midbrain, pointing to the mitochondria as a site of action of VEGF-B. GDNF showed a positive correlation with nuclear-encoded mitochondrial genes that was not nearly as strong (p = 0.018). VEGF-B counteracted rotenone-induced reduction of (a) fatty acid transport protein 1 and 4 levels and (b) both Akt protein and phosphorylation levels in SH-SY5Y cells. We further verified VEGF-B expression in the human SN pars compacta of healthy controls and Parkinson’s disease patients, in neuronal cells that show co-expression with neuromelanin. These results have demonstrated that VEGF-B has potential as a neuroprotective agent for PD therapy and should be further investigated. PMID:24291725

Yue, Xu; Hariri, Dana J.; Caballero, Beatrice; Zhang, Shiling; Bartlett, Mitchell J.; Kaut, Oliver; Mount, David W.; Wüllner, Ullrich; Sherman, Scott J.; Falk, Torsten

2014-01-01

291

Nonhuman primate embryonic stem cells as a preclinical model for hematopoietic and vascular repair.  

PubMed

Stem cell-based regenerative medicine therapies have been touted recently as a novel therapeutic approach to treat and cure a wide range of diseases. Both adult and embryonic stem (ES) cells can serve as important sources of precursor cells to derive more mature cells potentially utilized for clinical applications. Nonhuman primates have proven useful as a preclinical model, as demonstrated in studies of hematopoietic cell transplantation, gene therapy, and other areas. The derivation of nonhuman primate ES cells now provides an optimal resource to characterize and test ES cell-based therapies prior to trials with human ES cells. This review describes work to define strategies and mechanisms to derive blood and endothelial cells from nonhuman primate ES cells isolated from various species. Preclinical testing that solely relies on studies of putative therapeutic cells derived from mouse ES cells transplanted into other mice, or analyses of human ES cell-derived cells transplanted into immunodeficient or immunosuppressed rodents may not be predictive of efficacy in subsequent human trials. However, future testing using nonhuman primate ES cell-derived therapeutic cells done as an allogeneic transplant may best predict success for subsequent studies using human ES cells. Therefore, additional research on nonhuman primate ES cells, in addition to work on mouse and human ES cells, is greatly needed to facilitate clinical translation of new stem cell treatments. PMID:16140145

Hematti, Peiman; Obrtlikova, Petra; Kaufman, Dan S

2005-09-01

292

Preclinical and clinical characteristics of rivaroxaban: a novel, oral, direct factor Xa inhibitor.  

PubMed

There are several novel anticoagulants in development that target factor Xa(FXa)-the pivotal point of the coagulation cascade. One promising agent is rivaroxaban (a highly selective, oral, direct FXa inhibitor), which is in advanced clinical development for the prevention and treatment of thromboembolic disorders. Oral rivaroxaban may be given in fixed once-daily doses, with the potential for no coagulation monitoring. These properties, along with results from preclinical and clinical studies, suggest that rivaroxaban may have advantages over current treatments. Studies in arterial and venous animal models demonstrated that rivaroxaban has potent antithrombotic effects, without prolonging bleeding times. In healthy subjects, rivaroxaban was well tolerated, with a predictable pharmacological profile and a low propensity for clinically relevant drug-drug interactions. Phase II studies of rivaroxaban for the prevention of venous thromboembolism (VTE) after major orthopedic surgery support these findings. The results also suggested that a total daily dose range of 5 to 20 mg rivaroxaban had similar efficacy and safety to enoxaparin, and that 10 mg rivaroxaban once daily was the optimal dose. This review assesses the preclinical and clinical characteristics of rivaroxaban, and discusses phase II findings with rivaroxaban for the prevention of VTE after major orthopedic surgery. PMID:17629849

Laux, Volker; Perzborn, Elisabeth; Kubitza, Dagmar; Misselwitz, Frank

2007-07-01

293

Development of a Preclinical Therapeutic Model of Human Brain Metastasis with Chemoradiotherapy  

PubMed Central

Currently, survival of breast cancer patients with brain metastasis ranges from 2 to 16 months. In experimental brain metastasis studies, only 10% of lesions with the highest permeability exhibited cytotoxic responses to paclitaxel or doxorubicin. Therefore, radiation is the most frequently used treatment, and sensitizing agents, which synergize with radiation, can improve the efficacy of the therapy. In this study we used 435-Br1 cells containing the fluorescent protein (eGFP) gene and the photinus luciferase (PLuc) gene to develop a new brain metastatic cell model in mice through five in vivo/in vitro rounds. BR-eGFP-CMV/Luc-V5 brain metastatic cells induce parenchymal brain metastasis within 60.8 ± 13.8 days of intracarotid injection in all mice. We used this model to standardize a preclinical chemoradiotherapy protocol comprising three 5.5 Gy fractions delivered on consecutive days (overall dose of 16.5 Gy) which improved survival with regard to controls (60.29 ± 8.65 vs. 47.20 ± 11.14). Moreover, the combination of radiotherapy with temozolomide, 60 mg/Kg/day orally for five consecutive days doubled survival time of the mice 121.56 ± 52.53 days (Kaplan-Meier Curve, p < 0.001). This new preclinical chemoradiotherapy protocol proved useful for the study of radiation response/resistance in brain metastasis, either alone or in combination with new sensitizing agents. PMID:23591844

Martínez-Aranda, Antonio; Hernández, Vanessa; Picón, Cristina; Modolell, Ignasi; Sierra, Angels

2013-01-01

294

Evaluation Of Microdosing Strategies For Studies In Preclinical Drug Development: Demonstration Of Linear Pharmacokinetics In Dogs Of A Nucleoside Analogue Over A 50-Fold Dose Range  

SciTech Connect

The technique of accelerator mass spectrometry (AMS) was validated successfully and utilized to study the pharmacokinetics and disposition in dogs of a preclinical drug candidate (Compound A), after oral and intravenous administration. The primary objective of this study was to examine whether Compound A displayed linear kinetics across sub-pharmacological (microdose) and pharmacological dose ranges in an animal model, prior to initiation of a human microdose study. The AMS-derived disposition properties of Compound A were comparable to data obtained via conventional techniques such as LC-MS/MS and liquid scintillation counting analyses. Thus, Compound A displayed multiphasic kinetics and possessed low plasma clearance (4.4 mL/min/kg), a long terminal elimination half-life (19.4 hr) and high oral bioavailability (82%). Currently there are no published comparisons of the kinetics of a pharmaceutical compound at pharmacological versus sub-pharmacological doses employing microdosing strategies. The present study thus provides the first description of the pharmacokinetics of a drug candidate assessed under these two dosing regimens. The data demonstrated that the pharmacokinetic properties of Compound A were similar following dosing at 0.02 mg/kg as at 1 mg/kg, indicating that in the case of Compound A, the kinetics of absorption, distribution and elimination in the dog appear to be linear across this 50-fold dose range. Moreover, the exceptional sensitivity of AMS provided a pharmacokinetic profile of Compound A, even following a microdose, which revealed aspects of the disposition of this agent that were inaccessible by conventional techniques. The applications of accelerator mass spectrometry (AMS) are broad ranging and vary from studying environmental and ecological issues such as the isotopic composition of the atmosphere, soil and water (Hughen et al., 2000; Beck et al., 2001; Keith-Roach et al., 2001; Mironov et al., 2002), to archaeology and volcanology (Stafford et al., 1984; Vogel et al., 1990; Smith et al., 1999) to its use as a bioanalytical tool for nutritional research (Buchholz et al., 1999; Deuker et al., 2000; Weaver and Liebman, 2002). Biomedical applications of AMS and its use in the arena of pharmaceutical research also have been detailed in review articles (Barker and Garner, 1999; Garner, 2000; Turteltaub and Vogel, 2000). To date, most studies on the metabolism and disposition of xenobiotics by AMS have focused on how carcinogens bind to DNA and proteins to form adducts (Turteltaub et al., 1990, 1997; Frantz et al., 1995; Dingley et al., 1999; Li et al., 2003). Its application to the field of pharmaceutical sciences has been limited to a few studies (Kaye et al., 1997; Young et al., 2001; Garner et al., 2002). However, the pharmaceutical industry is becoming increasingly aware of the potential benefits that may accrue from the ultra high sensitivity afforded by AMS in terms of evaluating the pharmacokinetics of lead drug candidates in early development. Specifically, AMS allows administration of sub-pharmacological doses (microdoses) of carbon-14 or tritium-labeled investigational drugs to animals or humans at radiologically insignificant levels with the goal of obtaining preliminary information regarding the absorption, distribution, metabolism, and excretion of test compounds (Turteltaub and Vogel, 2000). An unresolved issue, however, is whether the pharmacokinetics determined following a microdose are representative of those following a conventional (pharmacological) dose (Lappin and Garner, 2003). This paper examines the linearity of kinetics of an antiviral nucleoside analogue, Compound A, across sub-pharmacological and pharmacological dose ranges in the dog prior to initiation of a human microdose study. The specific objectives of this study, therefore, were (1) to assess the pharmacokinetics of Compound A in dogs by a conventional dosing approach utilizing LC-MS/MS for sample analysis, (2) to assess the pharmacokinetics of Compound A in dogs by the microdose approach utilizing AMS for sample ana

Sandhu, P; Vogel, J S; Rose, M J; Ubick, E A; Brunner, J E; Wallace, M A; Adelsberger, J K; Baker, M P; Henderson, P T; Pearson, P G; Baillie, T A

2004-04-22

295

Route of Administration of the TLR9 Agonist CpG Critically Determines the Efficacy of Cancer Immunotherapy in Mice  

Microsoft Academic Search

BackgroundThe TLR9 agonist CpG is increasingly applied in preclinical and clinical studies as a therapeutic modality to enhance tumor immunity. The clinical application of CpG appears, however, less successful than would be predicted from animal studies. One reason might be the different administration routes applied in most mouse studies and clinical trials. We studied whether the efficacy of CpG as

Stefan Nierkens; Martijn H. den Brok; Thijs Roelofsen; Jori A. L. Wagenaars; Carl G. Figdor; Theo J. Ruers; Gosse J. Adema; Roberto F. Speck

2009-01-01

296

Route of administration of the TLR9 agonist CpG critically determines the efficacy of cancer immunotherapy in mice  

Microsoft Academic Search

BACKGROUND: The TLR9 agonist CpG is increasingly applied in preclinical and clinical studies as a therapeutic modality to enhance tumor immunity. The clinical application of CpG appears, however, less successful than would be predicted from animal studies. One reason might be the different administration routes applied in most mouse studies and clinical trials. We studied whether the efficacy of CpG

Stefan Nierkens; Martijn H. den Brok; Thijs Roelofsen; Jori A. L. Wagenaars; Carl G. Figdor; Theo J. Ruers; Gosse J. Adema

2009-01-01

297

A Study Strategies Self-Efficacy Instrument for Use with Community College Students.  

ERIC Educational Resources Information Center

Studied the dimensionality of responses to the Study Skills Self-Efficacy Scale (M. Ramirez and S. Owen, 1991) using exploratory factor analysis and investigated the use of Rasch measures in differentiating between groups of students who report being academically successful or at risk. Results for 550 college students indicate that responses…

Silver, Bethany B.; Smith, Everett V., Jr.; Greene, Barbara A.

2001-01-01

298

Case Study: Influence of Tracking on Achievement, Self-Efficacy and Instruction  

ERIC Educational Resources Information Center

Focusing on a suburban Philadelphia high school's social studies classes, this research study investigated the influence of tracking on student achievement, on teachers' and students' perceptions of self-efficacy, and on teachers' instructional practices in the classroom. In order to address these research questions, the researcher used a…

Butz, Toni R.

2011-01-01

299

A Reliability Generalization Study of the Teacher Efficacy Scale and Related Instruments.  

ERIC Educational Resources Information Center

Studied sources of measurement error variance in the Teacher Efficacy Scale (TES) (Gibson and Dembo, 1984). Used reliability generalization to characterize the typical score reliability for the TES and potential sources of measurement error variance across 43 studies. Also examined related instruments for measurement integrity. (SLD)

Henson, Robin K.; Kogan, Lori R.; Vacha-Haase, Tammi

2001-01-01

300

Efficacy of nebulized budesonide in treatment of severe infantile asthma: A double-blind study  

Microsoft Academic Search

Background and Objective: Treatments with inhaled corticosteroids yielded conflicting results in infants with severe asthma. The purpose of this study was to assess the efficacy of nebulized budesonide on the control of asthma in this age group. Methods: In a double-blind, placebo-controlled study, 40 infants with severe asthma received either nebulized budesonide (1 mg) or placebo twice daily for 12

Jacques de Blic; Christophe Delacourt; Muriel Le Bourgeois; Bruno Mahut; Juliette Ostinelli; Carole Caswell; Pierre Scheinmann

1996-01-01

301

Preclinical and Clinical Evaluation of Intraductally Administered Agents in Early Breast Cancer  

PubMed Central

Most breast cancers originate in the epithelial cells lining the breast ducts. Intraductal administration of cancer therapeutics would lead to high drug exposure to ductal cells and eliminate preinvasive neoplasms while limiting systemic exposure. We performed preclinical studies in N-methyl-N’-nitrosourea–treated rats to compare the effects of 5-fluorouracil, carboplatin, nanoparticle albumin-bound paclitaxel, and methotrexate to the previously reported efficacy of pegylated liposomal doxorubicin (PLD) on treatment of early and established mammary tumors. Protection from tumor growth was observed with all five agents, with extensive epithelial destruction present only in PLD-treated rats. Concurrently, we initiated a clinical trial to establish the feasibility, safety, and maximum tolerated dose of intraductal PLD. In each eligible woman awaiting mastectomy, we visualized one ductal system and administered dextrose or PLD using a dose-escalation schema (2 to 10 mg). Intraductal administration was successful in 15 of 17 women with no serious adverse events. Our preclinical studies suggest that several agents are candidates for intraductal therapy. Our clinical trial supports the feasibility of intraductal administration of agents in the outpatient setting. If successful, administration of agents directly into the ductal system may allow for “breast-sparing mastectomy” in select women. PMID:22030751

Stearns, Vered; Mori, Tsuyoshi; Jacobs, Lisa K.; Khouri, Nagi F.; Gabrielson, Edward; Yoshida, Takahiro; Kominsky, Scott L.; Huso, David L.; Jeter, Stacie; Powers, Penny; Tarpinian, Karineh; Brown, Regina J.; Lange, Julie R.; Rudek, Michelle A.; Zhang, Zhe; Tsangaris, Theodore N.; Sukumar, Saraswati

2013-01-01

302

[Comparative study of drug efficacy and drug additives between generic drugs and original drugs].  

PubMed

In the present study, we tested three kinds of sleeping drugs, consisting mainly of triazolam, brotizolam, and flunitrazepam, to compare the drug efficacy of generic drugs with that of original drugs. After these drugs were administered orally to mice, drug efficacy was evaluated in terms of ambulation, onset time of sleep, and duration of sleep in the open field test. For all kinds of sleep-inducing drugs, the drug efficacy of most generic drugs is not necessarily equal to that of the original drug. The main reason for the difference appears to be due to differences in the rate of absorption of the main drug. Any other differences between an original drug and a generic drug are caused by drug additives, the crystal form of the main drug, the formulation, and so on. In this study, the formulation was not the reason for the differences because all of the drugs were pulverized in a mortar and had no special coating. The drug additives for all the drugs are listed and the drug efficacy compared. Unfortunately, the information was not sufficient to shed any light on the differences in drug efficacy. For effective drug therapy, more information on drug additives should be provided. PMID:18057791

Katoh, Hiromi; Yoshii, Michiko; Ozawa, Koichiro

2007-12-01

303

Preclinical evaluation of new anthracyclines.  

PubMed

We designed a screening system for new anthracyclines totally based on human tumor material. In the first step of the system, the relative cytotoxicity versus doxorubicin of all new compounds is investigated in a panel of human tumor cell lines, well characterized for resistance factors and p53 status. Only a few analogs are selected through this step for further evaluation. The second step is aimed to investigate the therapeutic efficacy and the tolerability of the analog, which is compared to doxorubicin in a series of human tumor xenografts selected for presenting natural or acquired (by known mechanisms) resistance to the parent drug. Cardiotoxicity in mice is also studied. Cellular and molecular pharmacology studies are also considered. The results of a series of disaccharide anthracycline analogs screened by the system are presented. An analog of the series, MEN 10755, was selected for clinical investigation and is currently evaluated in Phase I trials. The ability of human tumor xenografts to predict the clinical efficacy of anthracycline analogs is also discussed. PMID:11172688

Pratesi, G; Monestiroli, S V

2001-01-01

304

MRI-monitored transcatheter intraarterial delivery of SPIO-labeled natural killer cells to hepatocellular carcinoma: preclinical studies in a rodent model  

PubMed Central

Object To test the hypotheses that intraarterial (IA) infusion allows for targeted natural killer (NK) lymphocyte delivery to hepatocellular carcinoma (HCC) and that iron oxide labeling allows for quantitative visualization of IA NK delivery with magnetic resonance imaging (MRI). Materials and Methods Experiments received institutional animal care and use committee approval. NK-92MI cells were labeled with superparamagnetic iron oxide (SPIO) nanoparticles. Cell viability, labeling efficacy, and cell phantom imaging studies were performed. Six rats were each implanted with two HCC tumors. Catheter was placed in proper hepatic artery for NK infusion. MRI T2* measurements for tumor and normal liver were compared pre and post infusion and correlated with histological measurements; Prussian blue staining was used for labeled NK identification. Spearman correlation coefficients and t-tests were calculated for statistical analyses. Results Increasing SPIO incubation concentration decreased cell viability. Labeling efficacy was 88.0±3.1% (mean±SD) across samples. The spatial extent of T2*-weighted contrast and R2* relaxivity values increased for cell phantom samples incubated with increasing SPIO concentrations. T2* measurements decreased in the tumor and normal liver tissues after NK infusion (p<0.001); ?T2* was greater in tumors than in normal liver tissue (p<0.001). Histological measurements demonstrated increased NK delivery to the tumor compared to the normal liver (p<0.001). ?T2* was well-correlated with histological NK measurements (?=0.70). Conclusion IA infusion permitted selective delivery of NK cells to HCC. Transcatheter delivery of SPIO-labeled NK cells can be quantitatively visualized with MRI. PMID:23249649

Sheu, Alexander Y.; Zhang, Zhuoli; Omary, Reed A.; Larson, Andrew C.

2013-01-01

305

Radio-decontamination efficacy and safety studies on optimized decontamination lotion formulation.  

PubMed

Objective of the present study was to optimize decontamination lotion and to evaluate its relative decontamination efficacy using three radio-isotopes (Technetium-99m, Iodine-131 and Thallium-201) as contaminants with varying length of contaminant exposure (0-1h). Experiments were performed on Sprague Dawley rat's intact skin and human tissue equivalent models. Rat's hair was removed by using depilator after trimming with scissors. Relative decontamination efficacy of the optimized lotion was investigated and compared with water as control. Static counts were recorded before and after decontamination using single photon emission computed tomography (SPECT). Measured decontamination efficacy (DE) values were analyzed using one way ANOVA and Student's t-test (p value<0.05) and were found statistically significant. Decontamination efficacy of the lotion was observed to be 90 ± 5%, 80 ± 2% and 85 ± 2%, for the (131)I, (201)Tl and (99m)Tc radio-contaminants respectively on skin. Reduced contaminant removal was recorded for the skin which was cleaned by depilator (50-60%). Skin decontamination was found more efficacious for rat skin decontamination than the human tissue equivalent model. Decontamination efficacy of the lotion against (99m)Tc was recorded 70 ± 15% at 0-1h on the tissue equivalent model. In vitro chelation efficacy of the lotion was also established by using the instant thin layer chromatography-slica gel (ITLC-SG) and >95% of (99m)Tc was recorded. Neither erythema nor edema was scored in the primary skin irritancy test visually observed for two weeks. PMID:22609966

Rana, S; Bhatt, S; Dutta, M; Khan, A W; Ali, J; Sultana, S; Kotta, S; Ansari, S H; Sharma, R K

2012-09-15

306

Efficacy and tolerance of a comfrey root extract (Extr. Rad. Symphyti) in the treatment of ankle distorsions: results of a multicenter, randomized, placebo-controlled, double-blind study.  

PubMed

Comfrey (Symphytum officinale L.) is a medicinal plant with anti-inflammatory, analgesic and tissue regenerating properties. In a double-blind, multicenter, randomized, placebo-controlled, group comparison study on patients suffering from unilateral acute ankle sprains (n = 142, mean age 31.8 years, 78.9% male), the percutaneous efficacy of an ointment of comfrey extract (Kytta-Salbe f, four treatments per day for 8 days) was confirmed decisively. Compared to placebo, the active treatment was clearly superior regarding the reduction of pain (tonometric measurement, p<0.0001, as the primary efficacy variable) and ankle edema (figure-of-eight method, p = 0.0001). Statistically significant differences between active treatment and placebo could also be shown for ankle mobility (neutral zero method), and global efficacy. Under active treatment, no adverse drug reactions were reported. The good local and global tolerance of the trial medication could also be confirmed. The study results are consistent with the known pre-clinical and clinical data concerning comfrey. PMID:15500257

Koll, R; Buhr, M; Dieter, R; Pabst, H; Predel, H G; Petrowicz, O; Giannetti, B; Klingenburg, S; Staiger, C

2004-09-01

307

A Study of Nursing Competency, Career Self-efficacy, and Professional Commitment among Nurses in Taiwan.  

PubMed

Abstract Background: Professional commitment, maintaining nursing competency, and improving self-efficacy could be necessary to enhance the quality of care service in Taiwan. Aim: The purpose of this study was to investigate the relationships among nursing competency, career self-efficacy, and professional commitment in hospital nurses. Methods/Design: We used a stratified cluster random sampling method for the selection. To take seven hundred and sixty-two nurses with work experience of more than 6 months were selected from two regional hospitals and three district hospitals in Taiwan. The nurses answered a self-report questionnaire, which was categorized into four sections: personal background data, nursing competency, career self-efficacy, and professional commitment. Results/Findings: The results indicate that nursing competency and career selfefficacy of nurses were at a high level, whereas professional commitment was at a medium level. Nursing competency, career self-efficacy, and professional commitment were significantly positively correlated. Conclusion: The career self-efficacy and professional commitment of medical and nursing personnel can help to increase nursing competency and to improve the quality of medical and nursing care. PMID:25431197

Tsai, Chao-Wen; Tsai, Shieunt-Han; Chen, Ying-Ying; Lee, Wei-Lun

2014-11-28

308

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

PubMed

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-2r? 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

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

309

Study of the comparative efficacy of toltrazuril and diclazuril against ovine coccidiosis in housed lambs.  

PubMed

A blinded, controlled and randomised field study was conducted on a sheep farm with a known history of coccidiosis and a high prevalence mainly of the pathogenic coccidium Eimeria ovinoidalis. The efficacy of treatment with toltrazuril (Baycox 5% suspension) against natural infections with Eimeria crandallis and/or Eimeria ovinoidalis in housed lambs was investigated in comparison with diclazuril and untreated controls. Both drugs were administered either metaphylactically (i.e., in the prepatency of Eimeria spp.) or therapeutically (after onset of oocyst excretion). A total of 145 animals aged 1 to 5 days at the start of the study were included. Examination of faecal samples was performed every second day between days 13 and 49 of the study. The assessment of treatment efficacy was based mainly on total oocyst excretion and the number of E. crandallis and E. ovinoidalis oocysts (OPG) shed throughout the study. Oocyst excretion was reduced significantly in both groups treated with toltrazuril compared with the untreated control group and with both diclazuril-treated groups. The most prevalent and most severe diarrhoea was observed in the untreated control group. In this study, toltrazuril proved to be highly effective in controlling ovine coccidiosis both metaphylactically and therapeutically. The efficacy of toltrazuril was significantly higher than the efficacy of the control substance with regard to the duration and amount of oocyst excretion, both for the comparison of metaphylactic as well as therapeutic treatment. PMID:19575235

Mundt, Hans-Christian; Dittmar, Katja; Daugschies, Arwid; Grzonka, Elmar; Bangoura, Berit

2009-08-01

310

MEMS-enabled implantable drug infusion pumps for laboratory animal research, preclinical, and clinical applications.  

PubMed

Innovation in implantable drug delivery devices is needed for novel pharmaceutical compounds such as certain biologics, gene therapy, and other small molecules that are not suitable for administration by oral, topical, or intravenous routes. This invasive dosing scheme seeks to directly bypass physiological barriers presented by the human body, release the appropriate drug amount at the site of treatment, and maintain the drug bioavailability for the required duration of administration to achieve drug efficacy. Advances in microtechnologies have led to novel MEMS-enabled implantable drug infusion pumps with unique performance and feature sets. In vivo demonstration of micropumps for laboratory animal research and preclinical studies include acute rapid radiolabeling, short-term delivery of nanomedicine for cancer treatment, and chronic ocular drug dosing. Investigation of MEMS actuators, valves, and other microstructures for on-demand dosing control may enable next generation implantable pumps with high performance within a miniaturized form factor for clinical applications. PMID:22926321

Meng, Ellis; Hoang, Tuan

2012-11-01

311

Malaria Vaccine Adjuvants: Latest Update and Challenges in Preclinical and Clinical Research  

PubMed Central

There is no malaria vaccine currently available, and the most advanced candidate has recently reported a modest 30% efficacy against clinical malaria. Although many efforts have been dedicated to achieve this goal, the research was mainly directed to identify antigenic targets. Nevertheless, the latest progresses on understanding how immune system works and the data recovered from vaccination studies have conferred to the vaccine formulation its deserved relevance. Additionally to the antigen nature, the manner in which it is presented (delivery adjuvants) as well as the immunostimulatory effect of the formulation components (immunostimulants) modulates the immune response elicited. Protective immunity against malaria requires the induction of humoral, antibody-dependent cellular inhibition (ADCI) and effector and memory cell responses. This review summarizes the status of adjuvants that have been or are being employed in the malaria vaccine development, focusing on the pharmaceutical and immunological aspects, as well as on their immunization outcomings at clinical and preclinical stages. PMID:23710439

Mata, Elena; Salvador, Aiala; Igartua, Manoli; Hernández, Rosa María; Pedraz, José Luis

2013-01-01

312

[An experimental study of the efficacy of enterosorbents in salmonellosis].  

PubMed

The effectiveness of enterosorbents (polymethylsiloxane used as enterosgel and activated charcoal) has been studied in experiments on white rats infected with low virulent Salmonella typhimurium strain N 79. As shown in this study, the use of sorbents normalizes the morphofunctional characteristics of the epithelium of the small intestine and decreases the degree of Salmonella colonization of the parietal layer in the lumen of the small intestine, causing the destruction of some adsorbed bacteria. PMID:8017132

Nikolaeva, L G; Grigor'ev, A V; Znamenski?, V A; Koval'chuk, V K; Alekseenko, E P

1994-01-01

313

A Study of Secondary Science Teacher Efficacy and Level of Constructivist Instructional Practice Implementation in West Virginia Science Classrooms  

ERIC Educational Resources Information Center

The purpose of this study was to investigate the level of use of selected constructivist instructional practices and level of teacher efficacy in West Virginia secondary science classrooms. The study next sought to determine if a relationship existed between level of use of the constructivist practices and teacher efficacy. In addition the study…

Knapp, Amanda Kristen

2013-01-01

314

Developing Self-Efficacy within Role Players in Collegiate Athletics: A Mixed Methods Study  

ERIC Educational Resources Information Center

The purpose of this study was to examine the differences in the level of self-efficacy between starting players and role players in a college Midwest Division III men's football team. The research questions were: 1) What differences in satisfaction levels, if any, can be found among starting players and role players with coach leadership,…

Perchinsky, David A.

2012-01-01

315

Efficacy and safety of reuse of disposable laparoscopic instruments in laparoscopic cholecystectomy: a prospective randomized study  

Microsoft Academic Search

Background The aim of this prospective randomized study was to investigate the efficacy and safety of the reuse of disposable laparoscopic instruments (DLI) in laparoscopic cholecystectomy. Methods A total of 125 consecutive patients with symptomatic cholelithiasis were randomly assigned to undergo laparoscopic cholecystectomy with single-use DLI (group 1, n = 62) or DLI that were reused (group 2, n =

T. Colak; G. Ersoz; T. Akca; A. Kanik; S. Aydin

2004-01-01

316

A Quantitative Study Examining Teacher Stress, Burnout, and Self-Efficacy  

ERIC Educational Resources Information Center

The purpose of this quantitative, correlational study was to examine the relationships between stress, burnout, and self-efficacy in public school teachers in the Turks and Caicos Islands. The Teacher Stress Inventory was used to collect data on teacher stress, the Maslach Burnout Inventory Educators Survey was used to obtain data on teacher…

Stephenson, Timar D.

2012-01-01

317

A Study of Teacher Efficacy and Professional Learning Community in Quest Schools. Revised Version.  

ERIC Educational Resources Information Center

This report discusses the administration of two instruments to faculty at 19 schools involved in the Appalachia Educational Laboratory's Quest project, which helps schools with educational reform efforts and challenges norms embedded in traditional school cultures. This study examined several constructs, including teacher efficacy, professional…

Cowley, Kimberly S.

318

Differences between Online and Traditional Students: A Study of Motivational Orientation, Self-Efficacy, and Attitudes  

ERIC Educational Resources Information Center

The purpose of the present study was to evaluate the differences in demographic characteristics, motivational orientation, self-efficacy, and attitudes about technology between students who enrolled in a course offered in the traditional setting and those enrolled in the same course online. The two groups, each comprised of 27 students, were…

Stevens, Tara; Switzer, Carrie

2006-01-01

319

Allopregnanolone promotes regeneration and reduces ?-amyloid burden in a preclinical model of Alzheimer's disease.  

PubMed

Previously, we demonstrated that allopregnanolone (AP?) promoted proliferation of rodent and human neural progenitor cells in vitro. Further, we demonstrated that AP? promoted neurogenesis in the hippocampal subgranular zone (SGZ) and reversed learning and memory deficits in the male triple transgenic mouse model of Alzheimer's (3xTgAD). In the current study, we determined the efficacy of AP? to promote the survival of newly generated neural cells while simultaneously reducing Alzheimer's disease (AD) pathology in the 3xTgAD male mouse model. Comparative analyses between three different AP? treatment regimens indicated that AP? administered 1/week for 6 months was maximally efficacious for simultaneous promotion of neurogenesis and survival of newly generated cells and reduction of AD pathology. We further investigated the efficacy of AP? to impact A? burden. Treatment was initiated either prior to or post intraneuronal A? accumulation. Results indicated that AP? administered 1/week for 6 months significantly increased survival of newly generated neurons and simultaneously reduced A? pathology with greatest efficacy in the pre-pathology treatment group. AP? significantly reduced A? generation in hippocampus, cortex, and amygdala, which was paralleled by decreased expression of A?-binding-alcohol-dehydrogenase. In addition, AP? significantly reduced microglia activation as indicated by reduced expression of OX42 while increasing CNPase, an oligodendrocyte myelin marker. Mechanistic analyses indicated that pre-pathology treatment with AP? increased expression of liver-X-receptor, pregnane-X-receptor, and 3-hydroxy-3-methyl-glutaryl-CoA-reductase (HMG-CoA-R), three proteins that regulate cholesterol homeostasis and clearance from brain. Together these findings provide preclinical evidence for the optimal treatment regimen of AP? to achieve efficacy as a disease modifying therapeutic to promote regeneration while simultaneously decreasing the pathology associated with Alzheimer's disease. PMID:21918687

Chen, Shuhua; Wang, Jun Ming; Irwin, Ronald W; Yao, Jia; Liu, Lifei; Brinton, Roberta Diaz

2011-01-01

320

Efficacy behind activity - Phytotherapeutics are not different from pharmaceuticals.  

PubMed

Abstract Context: When evaluating bioactivity, efficacy, and toxicology of plant products, attention should be paid on pre-clinical versus clinical research. Objective: To emphasize an evidence-based approach in the field of phytotherapy research. Methods: The pyramid of scientific evidence was used in order to assess the quality of phytotherapy studies. Results and conclusion: In terms of evidence-based phytotherapy, a step-by-step approach, ascending the "pyramid" of scientific evidence, is essential in order to collect correct information useful to clinicians and physicians, leant on the robust foundations of in vitro/in vivo studies. PMID:25472494

Varoni, Elena Maria; Lodi, Giovanni; Iriti, Marcello

2014-12-01

321

Preclinical safety of recombinant human interleukin-18.  

PubMed

Recombinant human interleukin-18 (rHuIL-18) is currently in clinical trials for treatment of cancer. This report presents results of preclinical toxicity studies with rHuIL-18 in cynomolgus monkeys and recombinant murine IL-18 (rMuIL-18) in mice. The rHuIL-18 was administered intravenously in 1 or 2 different 5-day cycles at doses 0.3 to 75 mg/kg/day in monkeys. Decreases in red cell mass, neutrophil, and platelet counts, increases in monocyte and large unstained cell counts, and lymphoid hyperplasia in spleen and lymph nodes were mild, reversible, and likely related to the pharmacologic activity of IL-18. The only toxic effect was protein cast nephropathy, secondary to coprecipitation of administered IL-18 and Tamm-Horsfall protein in the distal nephron, that only occurred at 75 mg/kg/day. Other adverse effects of rHuIL-18 were related to strong immunogenicity in monkeys and were manifest only during a second dosing cycle. The rMuIL-18, at similar dosing levels and cycles in mice, resulted in reduced red cell mass, increased white blood cell counts, spleen and lymph node hyperplasia, and mild, reversible changes in intestine, liver, and lungs. Protein cast nephropathy occurred in mice at doses > or = 30 mg/kg/day. In conclusion, preclinical safety studies showed that rIL-18 was well tolerated at pharmacologically active doses in both monkeys and mice. PMID:14692624

Herzyk, Danuta J; Bugelski, Peter J; Hart, Timothy K; Wier, Patrick J

2003-01-01

322

Recent advances and novel strategies in pre-clinical formulation development: an overview.  

PubMed

Preclinical profiling for a New Chemical Entity (NCE), if carried out carefully, can be a good predictor of human clinical outcome. Along with the pre-clinical study design a thorough understanding of the physico-chemical properties of the drug candidate and a careful selection of the formulation development strategy are of high importance. The study scientist can experience various challenges in executing a pre-clinical study. This review article provides an overview of the significance of pre-formulation study parameters and their relevance to preclinical studies. Various physico-chemical properties such as solubility, partition co-efficient, and permeability are attributes critical to the performance of the drug substance. This article presents unique formulation development strategies for the successful completion of pre-clinical studies. Formulation development approach for a pre-clinical study involves taking into consideration various important factors such as duration of the study, Biopharmaceutics Classification System (BCS) of the drug, intended duration of action and the desired route of administration. These parameters play key role in the selection of solubilizers, surfactants, co-solvents and optimum pH for the formulation. Two most common routes of administration in the early screening of pharmaceuticals viz., oral and intravenous are emphasized. The article also describes recent advances in preclinical formulation development including selected examples of in vivo preclinical models for anti-cancer, anti-viral, anti-diabetic and anti-hypertensive drugs. Adherence to the regulatory requirement is also the key to successful completion of the preclinical development. An overview of preclinical formulation development along with basic concepts and the recent studies conducted in the past decade are presented in this review. PMID:21763367

Shah, Amit K; Agnihotri, Sunil A

2011-12-20

323

Assessment of Symptomatic and Neuroprotective Efficacy of Mucuna Pruriens Seed Extract in Rodent Model of Parkinson’s Disease  

Microsoft Academic Search

Mucuna pruriens (MP) has long been used in Indian traditional medicine as support in the treatment of Parkinson’s disease. However, no systematic\\u000a preclinical studies that aimed at evaluating the efficacy of this substance are available to date. This study undertook an\\u000a extensive evaluation of the antiparkinsonian effects of an extract of MP seeds known to contain, among other components, 12.5%

Sanjay Kasture; Silvia Pontis; Annalisa Pinna; Nicoletta Schintu; Liliana Spina; Rosanna Longoni; Nicola Simola; Mauro Ballero; Micaela Morelli

2009-01-01

324

Preclinical screening of histone deacetylase inhibitors combined with ABT-737, rhTRAIL/MD5-1 or 5-azacytidine using syngeneic Vk*MYC multiple myeloma  

PubMed Central

Multiple myeloma (MM) is an incurable malignancy with an unmet need for innovative treatment options. Histone deacetylase inhibitors (HDACi) are a new class of anticancer agent that have demonstrated activity in hematological malignancies. Here, we investigated the efficacy and safety of HDACi (vorinostat, panobinostat, romidepsin) and novel combination therapies using in vitro human MM cell lines and in vivo preclinical screening utilizing syngeneic transplanted Vk*MYC MM. HDACi were combined with ABT-737, which targets the intrinsic apoptosis pathway, recombinant human tumour necrosis factor-related apoptosis-inducing ligand (rhTRAIL/MD5-1), that activates the extrinsic apoptosis pathway or the DNA methyl transferase inhibitor 5-azacytidine. We demonstrate that in vitro cell line-based studies provide some insight into drug activity and combination therapies that synergistically kill MM cells; however, they do not always predict in vivo preclinical efficacy or toxicity. Importantly, utilizing transplanted Vk*MYC MM, we report that panobinostat and 5-azacytidine synergize to prolong the survival of tumor-bearing mice. In contrast, combined HDACi/rhTRAIL-based strategies, while efficacious, demonstrated on-target dose-limiting toxicities that precluded prolonged treatment. Taken together, our studies provide evidence that the transplanted Vk*MYC model of MM is a useful screening tool for anti-MM drugs and should aid in the prioritization of novel drug testing in the clinic. PMID:24030150

Matthews, G M; Lefebure, M; Doyle, M A; Shortt, J; Ellul, J; Chesi, M; Banks, K-M; Vidacs, E; Faulkner, D; Atadja, P; Bergsagel, P L; Johnstone, R W

2013-01-01

325

Preclinical pharmacology of midazolam  

PubMed Central

1 Midazolam, a new imidazobenzodiazepine, forms salts that are stable in water solution, and has an overall pharmacological potency similar to that of diazepam but a much shorter duration of action. It produces all the characteristic effects of the benzodiazepine class. 2 Its metabolites account for only a negligible part, if any, of its pharmacological effects observed in the mouse. 3 The time course of its anticonvulsant activity, studied with different experimental protocols and by different routes of administration, revealed an almost immediate onset of action. 4 Midazolam was lightly more potent, and its duration of action was shorter than diazepam, in enhancing presynaptic inhibition in the spinal cord of cats and in depressing spontaneous activity of cerebellar Purkinje cells in the rat. 5 Midazolam decreased spontaneous multiunit activity (MUA) in different nuclei of the brain in `encéphale isolé' rats. This depression was reversed by Ro 15-1788, a recently discovered selective benzodiazepine antagonist. 6 Midazolam and diazepam decreased the cyclic GMP level in the cerebellum of rats with about the same potency; the effect of midazolam was of much shorter duration than that of diazepam. 7 Midazolam had one-third the potency of diazepam in displacing 3H-flunitrazepam in mouse brain in vivo, and also in this case the effect of midazolam was of brief duration, as compared with diazepam. 8 Midazolam in therapeutic doses was virtually ineffective in the cardiovascular system of conscious dogs after p.o. or i.v. administration. No direct effects of the drug on autonomic functions were found. 9 The animal data suggest the usefulness of midazolam as an oral sleep-inducer, as an agent for i.v. induction of anaesthesia and as an i.v. or i.m. anticonvulsant in status epilepticus or tetanus, because of its rapid onset of action and its excellent local tolerance as water-soluble injection form. PMID:6138073

Pieri, L.

1983-01-01

326

In vivo models of brain tumors: roles of genetically engineered mouse models in understanding tumor biology and use in preclinical studies.  

PubMed

Although our knowledge of the biology of brain tumors has increased tremendously over the past decade, progress in treatment of these deadly diseases remains modest. Developing in vivo models that faithfully mirror human diseases is essential for the validation of new therapeutic approaches. Genetically engineered mouse models (GEMMs) provide elaborate temporally and genetically controlled systems to investigate the cellular origins of brain tumors and gene function in tumorigenesis. Furthermore, they can prove to be valuable tools for testing targeted therapies. In this review, we discuss GEMMs of brain tumors, focusing on gliomas and medulloblastomas. We describe how they provide critical insights into the molecular and cellular events involved in the initiation and maintenance of brain tumors, and illustrate their use in preclinical drug testing. PMID:25008045

Simeonova, Iva; Huillard, Emmanuelle

2014-10-01

327

Micro-ultrasound for preclinical imaging  

PubMed Central

Over the past decade, non-invasive preclinical imaging has emerged as an important tool to facilitate biomedical discovery. Not only have the markets for these tools accelerated, but the numbers of peer-reviewed papers in which imaging end points and biomarkers have been used have grown dramatically. High frequency ‘micro-ultrasound’ has steadily evolved in the post-genomic era as a rapid, comparatively inexpensive imaging tool for studying normal development and models of human disease in small animals. One of the fundamental barriers to this development was the technological hurdle associated with high-frequency array transducers. Recently, new approaches have enabled the upper limits of linear and phased arrays to be pushed from about 20 to over 50 MHz enabling a broad range of new applications. The innovations leading to the new transducer technology and scanner architecture are reviewed. Applications of preclinical micro-ultrasound are explored for developmental biology, cancer, and cardiovascular disease. With respect to the future, the latest developments in high-frequency ultrasound imaging are described. PMID:22866232

Foster, F. Stuart; Hossack, John; Adamson, S. Lee

2011-01-01

328

Collectivistic orientation, acculturative stress, cultural self-efficacy, and depression: a longitudinal study among chinese internal migrants.  

PubMed

The current study examined the longitudinal relationship of collectivistic orientation and depression and the mediating effects of acculturative stress and cultural self-efficacy between collectivistic orientation and depression. We expect that collectivistic orientation would decrease acculturative stress and increase cultural self-efficacy, and in turn, improve depression. Using data from 641 Chinese internal migrants during a 1-year period, the results supported the hypothesis that collectivistic orientation predicted decreased depression. Moreover, collectivistic orientation alleviated depression through reducing acculturative stress. Although cultural self-efficacy was also a significant mediator, collectivistic orientation relieved depression through decreasing cultural self-efficacy. Implications for future research directions and counseling are discussed. PMID:25480108

Du, Hongfei; Li, Xiaoming; Lin, Danhua; Tam, Cheuk Chi

2015-02-01

329

Preservice Elementary Teachers’ Development of Self-Efficacy and Confidence to Teach Science: A Case Study  

Microsoft Academic Search

This study examines the self-efficacy of one preservice elementary school teacher (Kasey) during and after her participation\\u000a in Science in Childhood Education—a 16-week, elementary preservice science methods course. The case study of this teacher\\u000a is situated in the context of the class as a whole. This is accomplished through interviewing the one teacher and examining\\u000a artifacts and observations of the

Amanda M. GunningFelicia; Felicia Moore Mensah

2011-01-01

330

PREVENT Cancer Preclinical Drug Development Program  

Cancer.gov

The PREVENT Cancer Drug Development Program is a National Cancer Institute-supported pipeline to bring new cancer preventing interventions and biomarkers through preclinical development towards clinical trials.

331

Preclinical Radiobiology and Predictive Assays  

NASA Astrophysics Data System (ADS)

Physical measurements of absorbed particle radiation doses are currently inadequate to estimate biological outcome at the stopping ranges of particle beams from protons to heavier ions. Estimates of biological significance and clinical impact are essential additional elements to implement ion beam therapy (IBT). This chapter provides a brief review of the current status of preclinical molecular and cellular radiobiology and predictive assays with a focus on the current use of radiobiology to characterize radiation fields of ions, to implement treatment planning with scanned ion beams, and to predict successful clinical outcome.

Blakely, Eleanor A.; Chang, Polly Y.

332

Mechanisms and preclinical efficacy of silibinin in preventing skin cancer  

Microsoft Academic Search

Eukaryotic cellular machineries including the genome face continuous challenge from environmental deleterious agents, as well as from the by products of their own metabolism. Our skin is the most important barrier. It protects us from xenobiotic and genotoxic agents including ultraviolet (UV) solar radiation and potential carcinogens, which are notorious for causing skin cancer. There is a rise in non-melanoma

Rana P. Singh; Rajesh Agarwal

2005-01-01

333

Preclinical efficacy of MEK inhibition in Nras-mutant AML  

PubMed Central

Oncogenic NRAS mutations are highly prevalent in acute myeloid leukemia (AML). Genetic analysis supports the hypothesis that NRAS mutations cooperate with antecedent molecular lesions in leukemogenesis, but have limited independent prognostic significance. Using short hairpin RNA–mediated knockdown in human cell lines and primary mouse leukemias, we show that AML cells with NRAS/Nras mutations are dependent on continued oncogene expression in vitro and in vivo. Using the Mx1-Cre transgene to inactivate a conditional mutant Nras allele, we analyzed hematopoiesis and hematopoietic stem and progenitor cells (HSPCs) under normal and stressed conditions and found that HSPCs lacking Nras expression are functionally equivalent to normal HSPCs in the adult mouse. Treating recipient mice transplanted with primary NrasG12D AMLs with 2 potent allosteric mitogen-activated protein kinase kinase (MEK) inhibitors (PD0325901 or trametinib/GlaxoSmithKline 1120212) significantly prolonged survival and reduced proliferation but did not induce apoptosis, promote differentiation, or drive clonal evolution. The phosphatidylinositol 3-kinase inhibitor GDC-0941 was ineffective as a single agent and did not augment the activity of PD0325901. All mice ultimately succumbed to progressive leukemia. Together, these data validate oncogenic N-Ras signaling as a therapeutic target in AML and support testing combination regimens that include MEK inhibitors. PMID:25361812

Burgess, Michael R.; Hwang, Eugene; Firestone, Ari J.; Huang, Tannie; Xu, Jin; Zuber, Johannes; Bohin, Natacha; Wen, Tiffany; Kogan, Scott C.; Haigis, Kevin M.; Sampath, Deepak; Lowe, Scott; Shannon, Kevin

2014-01-01

334

Preclinical dosimetry of magnetic fluid hyperthermia for bladder cancer  

NASA Astrophysics Data System (ADS)

Background Despite positive efficacy, thermotherapy is not widely used in clinical oncology. Difficulties associated with field penetration and controlling power deposition patterns in heterogeneous tissue have limited its use for heating deep in the body. Heat generation using iron-oxide super-paramagnetic nanoparticles excited with magnetic fields has been demonstrated to overcome some of these limitations. The objective of this preclinical study is to investigate the feasibility of treating bladder cancer with magnetic fluid hyperthermia (MFH) by analyzing the thermal dosimetry of nanoparticle heating in a rat bladder model. Methods The bladders of 25 female rats were injected with 0.4 ml of Actium Biosystems magnetite-based nanoparticles (Actium Biosystems, Boulder CO) via catheters inserted in the urethra. To assess the distribution of nanoparticles in the rat after injection we used the 7 T small animal MRI system (Bruker ClinScan, Bruker BioSpin MRI GmbH, Ettlingen, Germany). Heat treatments were performed with a small animal magnetic field applicator (Actium Biosystems, Boulder CO) with a goal of raising bladder temperature to 42°C in <10min and maintaining for 60min. Temperatures were measured throughout the rat with seven fiberoptic temperature probes (OpSens Technologies, Quebec Canada) to characterize our ability to localize heat within the bladder target. Results The MRI study confirms the effectiveness of the catheterization procedure to homogenously distribute nanoparticles throughout the bladder. Thermal dosimetry data demonstrate our ability to controllably raise temperature of rat bladder >1°C/min to a steady-state of 42°C. Conclusion Our data demonstrate that a MFH system provides well-localized heating of rat bladder with effective control of temperature in the bladder and minimal heating of surrounding tissues.

Oliveira, Tiago R.; Stauffer, Paul R.; Lee, Chen-Ting; Landon, Chelsea; Etienne, Wiguins; Maccarini, Paolo F.; Inman, Brant; Dewhirst, Mark W.

2013-02-01

335

Identification and characterization of psoralen and isopsoralen as potent CYP1A2 reversible and time-dependent inhibitors in human and rat preclinical studies.  

PubMed

Naturally occurring furanocoumarin compounds psoralen (PRN) and isopsoralen (IPRN) are bioactive constituents found in herbaceous plants. They are widely used as active ingredients in several Chinese herbal medicines. In this study, the CYP1A2 inhibitory potential of PRN and IPRN was investigated in rats in vitro and in vivo as well as in human liver microsomes. Both compounds exhibited reversible and time-dependent inhibition toward rat microsomal cyp1a2. The IC(50), k(inact), and K(I) values were 10.4 ± 1.4 ?M, 0.060 ± 0.002 min(-1), and 1.13 ± 0.12 ?M for PRN, and 7.1 ± 0.6 ?M, 0.10 ± 0.01 min(-1), and 1.95 ± 0.31 ?M for IPRN, respectively. In human liver microsomal incubations, potent reversible CYP1A2 inhibition was observed for both compounds, with IC(50) values of 0.26 ± 0.01 ?M and 0.22 ± 0.03 ?M for PRN and IPRN, respectively. However, time-dependent inhibition was only observed for IPRN, with kinact and KI values of 0.050 ± 0.002 min(-1) and 0.40 ± 0.06 ?M, respectively. Coadministration with PRN or IPRN significantly inhibited cyp1a2 activity in rats, with the area under the curve (AUC) of phenacetin increasing more than 5-fold. Simcyp simulation predicted that PRN would cause 1.71- and 2.12-fold increases in the phenacetin AUC in healthy volunteers and smokers, respectively. IPRN, on the other hand, would result in 3.24- and 5.01-fold increases in phenacetin AUCs in healthy volunteers and smokers, respectively. These findings represent the first detailed report comparing the potential drug-drug interactions of PRN and IPRN, and provide useful information for balancing safe and efficacious doses of PRN and IPRN. PMID:23975028

Zhuang, Xiao-Mei; Zhong, Yu-Huan; Xiao, Wei-Bin; Li, Hua; Lu, Chuang

2013-11-01

336

Adult Attachment, Social Self-Efficacy, Self-Disclosure, Loneliness, and Subsequent Depression for Freshman College Students: A Longitudinal Study  

ERIC Educational Resources Information Center

This longitudinal study examined whether social self-efficacy and self-disclosure serve as mediators between attachment and feelings of loneliness and subsequent depression. Participants were 308 freshmen at a large Midwestern university. Results indicated that social self-efficacy mediated the association between attachment anxiety and feelings…

Wei, Meifen; Russel, Daniel W.; Zakalik, Robyn A.

2005-01-01

337

Efficacy of Atomoxetine in Children with Severe Autistic Disorders and Symptoms of ADHD: An Open-Label Study  

ERIC Educational Resources Information Center

Objective: This study aims to examine the efficacy of atomoxetine in treating symptoms of attention deficit hyperactivity disorder (ADHD) in children with severe autistic disorder. Method: Children with severe autistic disorder who had symptoms of ADHD were given atomoxetine for 10 weeks. The efficacy of atomoxetine was evaluated by using the…

Charnsil, Chawanun

2011-01-01

338

A Study of Factors That Contribute to Pre-Service Teachers' Sense of Efficacy for Literacy Instruction  

ERIC Educational Resources Information Center

The three-fold purpose of this mixed methods study was to (a) analyze how preservice teachers' perceptions of teacher preparation program variables affect preservice teachers self-efficacy for literacy instruction, (b) determine how preservice teachers describe their teacher preparation program with regard to self-efficacy beliefs for…

Martin, Charlene

2012-01-01

339

Exploring inclusion preservice training needs: a study of variables associated with attitudes and self?efficacy beliefs  

Microsoft Academic Search

The study examined attitudes towards inclusion and sense of efficacy of 1155 Israeli preservice teachers and variables related to these beliefs. Participants responded to an Options related to inclusion scale, and a Teacher efficacy scale. Findings revealed strong support for the principle of inclusion, yet also support for segregated special education placements. Several concerns regarding inclusion were expressed, which were

Shlomo Romi; Yona Leyser

2006-01-01

340

Teachers' Sense of Self-Efficacy, English Proficiency, and Instructional Strategies: A Study of Nonnative EFL Teachers in Iran  

ERIC Educational Resources Information Center

This study examined the efficacy beliefs of nonnative English speaking (NNES) Iranian EFL teachers. EFL teachers' perceptions of their teaching efficacy in terms of personal capabilities to teach English as a Foreign Language (EFL) and their perceived English language proficiency level were examined. A modified version of the Teacher Sense of…

Eslami, Zohreh R.; Fatahi, Azizullah

2008-01-01

341

Potential of metabolomics in preclinical and clinical drug development.  

PubMed

Metabolomics is an upcoming technology system which involves detailed experimental analysis of metabolic profiles. Due to its diverse applications in preclinical and clinical research, it became an useful tool for the drug discovery and drug development process. This review covers the brief outline about the instrumentation and interpretation of metabolic profiles. The applications of metabolomics have a considerable scope in the pharmaceutical industry, almost at each step from drug discovery to clinical development. These include finding drug target, potential safety and efficacy biomarkers and mechanisms of drug action, the validation of preclinical experimental models against human disease profiles, and the discovery of clinical safety and efficacy biomarkers. As we all know, nowadays the drug discovery and development process is a very expensive, and risky business. Failures at any stage of drug discovery and development process cost millions of dollars to the companies. Some of these failures or the associated risks could be prevented or minimized if there were better ways of drug screening, drug toxicity profiling and monitoring adverse drug reactions. Metabolomics potentially offers an effective route to address all the issues associated with the drug discovery and development. PMID:25443721

Kumar, Baldeep; Prakash, Ajay; Ruhela, Rakesh Kumar; Medhi, Bikash

2014-12-01

342

Long-Term Efficacy and Tolerability of Lanthanum Carbonate: Results from a 3Year Study  

Microsoft Academic Search

Background: Control of serum phosphate over the long term is essential in patients with end-stage renal disease. Six-month and 2-year extensions to a 6-month study evaluated the long-term safety, tolerability and efficacy of the new phosphate binder lanthanum carbonate. Methods: Patients who participated in a 6-month, randomized trial comparing lanthanum carbonate with calcium carbonate were eligible for a 24-week, open-label

Alastair J. Hutchison; Bart Maes; Johan Vanwalleghem; Gernot Asmus; Elfatih Mohamed; Roland Schmieder; Wolfgang Backs; Rene Jamar; Andre Vosskühler

2006-01-01

343

Study of the Comparative Efficacy of Toltrazuril and Diclazuril against Ovine Coccidiosis in Housed Lambs  

Microsoft Academic Search

A blinded, controlled and randomised field study was conducted on a sheep farm with a known history of coccidiosis and a high\\u000a prevalence mainly of the pathogenic coccidium Eimeria ovinoidalis. The efficacy of treatment with toltrazuril (Baycox® 5 % suspension) against natural infections with Eimeria crandallis and\\/or Eimeria ovinoidalis in housed lambs was investigated in comparison with diclazuril and untreated

Hans-Christian Mundt; Katja Dittmar; Arwid Daugschies; Elmar Grzonka; Berit Bangoura

2009-01-01

344

Chemoradiation for advanced hypopharyngeal carcinoma: a retrospective study on efficacy, morbidity and quality of life  

Microsoft Academic Search

Chemoradiation (CRT) is a valuable treatment option for advanced hypopharyngeal squamous cell cancer (HSCC). However, long-term\\u000a toxicity and quality of life (QOL) is scarcely reported. Therefore, efficacy, acute and long-term toxic effects, and long-term\\u000a QOL of CRT for advanced HSCC were evaluated,using retrospective study and post-treatment quality of life questionnaires. in\\u000a a tertiary hospital setting. Analysis was performed of 73

Stijn Keereweer; Jeroen D. F. Kerrebijn; Abrahim Al-Mamgani; Aniel Sewnaik; Robert J. Baatenburg de Jong; Esther van Meerten

2011-01-01

345

Encouraging mathematics participation through improved self-efficacy: a school counseling outcomes study  

Microsoft Academic Search

This article presents findings from a study investigating the effects of a middle school counseling intervention, using a specially designed curriculum, on participating students' attitudes, self-efficacy, and performance in mathematics. Hierarchical linear modeling was used to test for main effects between condition and sex and condition x sex interaction effects on all outcome measures across 3 time points: pre-intervention, post-intervention,

Lia D. Falco; Jessica J. Summers; Sheri Bauman

2010-01-01

346

Safety biomarkers in preclinical development: translational potential.  

PubMed

The identification, application, and qualification of safety biomarkers are becoming increasingly critical to successful drug discovery and development as companies are striving to develop drugs for difficult targets and for novel disease indications in a risk-adverse environment. Translational safety biomarkers that are minimally invasive and monitor drug-induced toxicity during human clinical trials are urgently needed to assess whether toxicities observed in preclinical toxicology studies are relevant to humans at therapeutic doses. The interpretation of data during the biomarker qualification phase should include careful consideration of the analytic method used, the biology, pharmacokinetic and pharmacodynamic properties of the biomarker, and the pathophysiology of the process studied. The purpose of this review is to summarize commonly employed technologies in the development of fluid- and tissue-based safety biomarkers in drug discovery and development and to highlight areas of ongoing novel assay development. PMID:24091814

Sasseville, V G; Mansfield, K G; Brees, D J

2014-01-01

347

Overall efficacy and safety results of sofosbuvir-based therapies in phase II and III studies.  

PubMed

The uridine nucleotide analogue sofosbuvir is a selective hepatitis C virus NS5B polymerase inhibitor, active regardless of genotype. We analyzed data on efficacy and safety of sofosbuvir, either in combination with pegylated interferon alfa-2a and ribavirin, or in combination with ribavirin alone as part of an interferon free regimen in more than 1300 patients. Treatment with sofosbuvir for 12 weeks in combination with P/R, in naïve genotype 1 patients was mainly studied in Neutrino. The efficacy of sofosbuvir as part of an all-oral combination including ribavirin alone, was explored in 555 naïve, ineligible and previous treatment failure genotype 2/3 patients. Rates of Sustained Viral Response in genotype 1 and 2 were higher than 85%. For genotype 3 and 4, a European study, Valence, and a US study on patients of Egyptian origin showed that naïve patients are cured at high rates by the all-oral combination given for 24 weeks. The efficacy of sofosbuvir plus P/R for 12 weeks in previous treatment failure genotype 3 has also been demonstrated. Sofosbuvir-based combinations are safe and well tolerated without side effects directly related to the drug. A large body of evidence suggests that sofosbuvir marks a revolution in HCV treatment. PMID:25458780

Mangia, Alessandra; Piazzolla, Valeria

2014-12-15

348

Prospective comparative study of efficacy and toxicity of netilmicin and amikacin.  

PubMed Central

Eighty patients were treated with either amikacin or netilmicin in a prospective randomized study of serious gram-negative bacillary infections, including 11 due to gentamicin-resistant pathogens. Thirty-six treated with netilmicin and 35 treated with amikacin were evaluable for efficacy or toxicity, or both. The overall groups differed significantly only in age. There were no significant differences in efficacy of the two drugs. There were no statistically significant differences at the 95% level between the netilmicin group and the amikacin group with respect to nephrotoxic reactions (38 versus 28%, respectively) or ototoxic reactions (9 versus 25%, respectively). Further comparative trials of netilmicin and other aminoglycosides appear warranted before it is widely used. PMID:6992711

Bock, B V; Edelstein, P H; Meyer, R D

1980-01-01

349

A study of secondary science teacher efficacy and level of constructivist instructional practice implementation in West Virginia science classrooms  

NASA Astrophysics Data System (ADS)

The purpose of this study was to investigate the level of use of selected constructivist instructional practices and level of teacher efficacy in West Virginia secondary science classrooms. The study next sought to determine if a relationship existed between level of use of the constructivist practices and teacher efficacy. In addition the study sought to determine if differences existed in level of use of the selected constructivist practices and/or teacher efficacy based on selected demographic variables. The study was a mixed-methods design. First, a researcher-developed survey instrument was used to collect data regarding the level of use of constructivist instructional practices. Efficacy data were collected using an adapted (with permission) version of the Teacher Self-Efficacy Scale ( TSES) by Tschannen-Moran, Hoy, and Hoy (1998). The study population consisted of secondary science teachers (middle, junior, and high school) in the state of West Virginia. The last survey question allowed educators to volunteer for a short follow-up interview to clarify the quantitative data. Overall, West Virginia science teachers reported frequent use of the selected constructivist instructional practices. Few significant differences were found based on the selected demographic variables. West Virginia science teachers reported moderately high efficacy levels. Few significant differences were found based on selected demographic variables. A moderate but significant correlation was found between teacher efficacy level and the level of use of the selected constructivist practices. The follow-up interviews clarified concepts and revealed barriers to implementation of new practices in the science classroom.

Knapp, Amanda Kristen

350

Increasing self-efficacy and quality lesson planning using Lesson-Study with elementary preservice teachers  

NASA Astrophysics Data System (ADS)

This qualitative, quasi-experimental study examined if lesson-study could be a successful approach in improving lesson plan quality and increasing self-efficacy levels toward teaching science at the preservice elementary teacher level in North Mississippi. Lesson-Study can be defined as a cycle of instructional improvement in which small groups work together to design and teach a lesson, revising again as needed over the course of a semester. This study described the experiences of two sections of preservice teachers enrolled in a science methods course as they engaged in lesson-study at a comprehensive university in Northeast Mississippi. One section of the class served as the control group while the other section, as the treatment group, received lesson-study over the course of the semester. Data was gathered in the form of interviews, observations, and a self-efficacy survey (STEBI-B). Lesson plans were also graded using a rubric to determine quality level. Findings indicated that, while not statistically significant, the treatment groups scores on the self-efficacy instrument increased more on average than the control groups' scores. There were also positive comments about the lesson study process from the teacher candidates in the treatment group as well as positive behaviors recorded by the researcher. Additionally, according to the external evaluators who graded the final drafts of the lessons, the treatment group had greater gains than the control class on average. These conclusions suggested the lesson study process implemented during the preservice teaching level can be beneficial.

Mitchell, Elizabeth Ann

351

A study of science teaching self-efficacy and outcome expectancy beliefs of teachers in India  

NASA Astrophysics Data System (ADS)

Elementary and middle school teachers in urban schools in India provided responses to the science efficacy instrument (STEBI-A). These responses were evaluated using Rasch analysis and parametric tests. Rasch fit statistics and person-item maps were evaluated. It was found that the instrument worked well for the two groups of teachers, but the differential item functioning analysis found that the teachers utilized several items in the scale differently. Parametric tests suggested that self-efficacy and outcome expectancy measures correlated highly for middle school teachers, for those that did not have a science degree and a written science curriculum. Significant predictors of self-efficacy are - minutes per week science is taught, educational level, number of days in the school year, holding of a science degree, and the presence of a science curriculum. From all of the analyses we conclude that teaching experience is important, but not necessarily enough to increase teachers' outcome expectancy beliefs. The results of this study should benefit educators and policy makers with respect to teacher education in India and around the world.

Shireen Desouza, Josephine M.; Boone, William J.; Yilmaz, Ozgul

2004-11-01

352

Safety and efficacy of leflunomide in primary Sjögren's syndrome: a phase II pilot study  

PubMed Central

Background For invalidating symptoms in primary Sjögren's syndrome (pSS), there is still a need for easy?to?administer, cost?effective and well?tolerated systemic treatment. Leflunomide (LEF) is structurally unrelated to other immunomodulatory drugs and might be efficacious in pSS, given its characteristic immunoregulatory modes of action. Objective To investigate the safety and efficacy of LEF in pSS in a phase II open?label pilot study. Methods 15 patients with pSS with early and active disease received LEF 20?mg once daily for 24?weeks. Tolerability, safety and efficacy of LEF were evaluated every 8?weeks. Additional safety visits were performed every fortnight. Results Mild gastrointestinal discomfort (including diarrhoea) and hair loss were mainly reported. Five patients developed lupus?like skin lesions on the face, arms or trunk, responding well to topical corticosteroids, nevertheless causing the withdrawal of one patient. Two patients with pre?existing hypertension had to increase dosages of anti?hypertensive drugs. Increased levels of alanine aminotransferase normalised after dose reduction in two patients. A decrease in general fatigue and an increase in physical functioning were observed after 24?weeks. Serum IgG levels decreased from 8?weeks onwards. Schirmer test values increased, not reaching statistical significance, whereas sialometry values did not change. In four of five repeated biopsies, the lymphocytic focus score decreased at the rate of 1 focus/4?mm2. A remarkable amelioration of leucocytoclastic vasculitis was observed in three patients. Conclusions Although the safety profile seems fairly acceptable, the observed indications for efficacy were modest and may be doubtful in justifying a randomised controlled trial of LEF in pSS. PMID:17223657

van Woerkom, J M; Kruize, A A; Geenen, R; van Roon, E N; Goldschmeding, R; Verstappen, S M M; van Roon, J A G; Bijlsma, J W J

2007-01-01

353

THE FEASIBILITY AND EFFICACY OF ECCENTRIC EXERCISE WITH OLDER CANCER SURVIVORS: A PRELIMINARY STUDY  

PubMed Central

Introduction Older individuals who have survived cancer, and the commensurate treatment, often experience a reduced quality of life in part due to their impaired muscular abilities and deficits in mobility. The purpose of this preliminary study was to determine the feasibility and preliminary efficacy of resistance exercise via negative, eccentrically-induced work (RENEW) with older cancer survivors. Methods Older cancer survivors with a perception of moderate muscle weakness and fatigue participated in 12 weeks of RENEW. Measures of feasibility included: 1) the participant’s ability to progress the total amount of work of RENEW; 2) whether peak knee extension torque production became impaired; and 3) whether RENEW induced leg muscle pain as measured on a visual analog scale. The preliminary measure of efficacy included: the performance of a timed up and go mobility test. Results The participants significantly increased the total average work per week over the 12 weeks of RENEW. Participants increased (p<0.001) their work ~3-fold from week 3 (7.6± 5.1 kJ) to week 12 (22.1±14.8kJ) without muscle pain over the 12 week RENEW training period. Knee extension peak torque production improved (11%) significantly (p=0.02) (pretest: 248 ±92 N; posttest: 275±99 N) after 12 weeks of RENEW. The time to perform the TUG test improved (14%) significantly (p<0.001) (pretest: 8.4±2.7; posttest: 7.2±2.3 s) after 12 weeks of RENEW, suggesting preliminary efficacy. Conclusion Collectively, RENEW appears feasible and potentially efficacious for older, weak and fatigued cancer survivors. Implications for Cancer Survivors The use of eccentric muscle exercise may be ideally suited for older cancer survivors due to its high force and low energetic cost capabilities. PMID:21155509

LaStayo, Paul C.; Larsen, Stephanie; Smith, Sheldon; Dibble, Lee; Marcus, Robin

2009-01-01

354

Pharmacokinetic and pharmacodynamic evaluation of the suitability of using fluticasone and an acute rat lung inflammation model to differentiate lung versus systemic efficacy.  

PubMed

Inhaled corticosteroids (ICSs) are often prescribed as the first line therapy for pulmonary diseases such as asthma. The biggest concern of using steroid therapy is the systemic side effects at high dose. To reduce the side effects, the pharmaceutical industry has been putting effort to generate new drugs with maximized topical efficacy. One of the key challenges is to differentiate efficacy from local versus systemic contribution in preclinical animal models. Fluticasone with various formulations was used as a model compound to explore the possibilities to demonstrate lung targeted efficacy by intratracheally instillation in the lipopolysaccharide induced inflammation rat model. Fluticasone formulations contained various surfactant concentrations and particle sizes to achieve lung retention and lower systemic exposure. Neutrophil infiltration in broncoalveolar lavage fluid and cytokine production in whole blood were measured to assess pulmonary efficacy versus systemic efficacy. PK/PD characterization of fluticasone with various formulations in the rat inflammation model provided an integrated approach in preclinical to evaluate lung targeted efficacy for ICS. Our study concluded that the combination of the rat LPS model and fluticasone is not suitable to use for establishing potency and dose requirement for new drug candidate designed for topical only efficacy. PMID:19230021

Chiang, Po-Chang; Hu, Yiding; Thurston, Archie; Sommers, Cynthia D; Guzova, Julia A; Kahn, Larry E; Lai, Yurong; Blom, Jason D

2009-11-01

355

Efficacy of methylsulfonylmethane supplementation on osteoarthritis of the knee: a randomized controlled study  

Microsoft Academic Search

Background  Patients with osteoarthritis (OA) take a variety of health supplements in an attempt to reduce pain and improve function.\\u000a The aim of this study was to determine the efficacy of methylsulfonylmethane (MSM) in treating patients with knee OA.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  This study was a prospective, randomized, double-blind, controlled clinical trial. Forty nine men and women 45-90 (mean 68\\u000a ± SD 7.3) years

Eytan M Debbi; Gabriel Agar; Gil Fichman; Yaron Bar Ziv; Rami Kardosh; Nahum Halperin; Avi Elbaz; Yiftah Beer; Ronen Debi

2011-01-01

356

21 CFR 310.6 - Applicability of “new drug” or safety or effectiveness findings in drug efficacy study...  

Code of Federal Regulations, 2012 CFR

21 Food and Drugs 5 2012-04-01 2012-04-01...drugâ or safety or effectiveness findings in drug efficacy study implementation notices...hearing to identical, related, and similar drug products. 310.6 Section...

2012-04-01

357

21 CFR 310.6 - Applicability of “new drug” or safety or effectiveness findings in drug efficacy study...  

Code of Federal Regulations, 2013 CFR

21 Food and Drugs 5 2013-04-01 2013-04-01...drugâ or safety or effectiveness findings in drug efficacy study implementation notices...hearing to identical, related, and similar drug products. 310.6 Section...

2013-04-01

358

[Efficacy of rasagiline in patients with advanced Parkinson's disease with motor fluctuation (azimut study)].  

PubMed

An open observational 3-month study of efficacy and safety of selective MAO B inhibitor rasagiline (?ZIlect) in advanced Parkinson's disease (PD) patients with m?tor fluctuations on the long-term levodopa therapy (the "?ZIMUT" study) has been conducted. Forty five non-demented patients with PD (mean age 64,7±8,4 years, mean duration of disease 9,5±4,0 years, mean Hoehn-Yahr stage 3,0±0,4, mean levodopa dose 673,9 mg/d) have been included in the study. All patients received rasagiline at a dose of 1 mg once daily as an adjunct to a stable anti-parkinsonian therapy. Patient's clinical state has been assessed at baseline and after 1 and 3 months of therapy. Forty two (93%) patients have completed the study. At the end of the third month of therapy, the daily off-time was decreased by 1,7 h. The ADL score (off-state) decreased by 22%, and the UPDRS-III score (on-state) decreased by 10%. The Global Clinical Improvement Scale revealed the marked improvement in 12% patients and moderate improvement in 43% patients. The severity of freezing of gait declined by 15%. Moreover, the initial severity of freezing seems to be a predictor of rasagiline clinical efficacy. The clinical effect of rasagiline steadily increased over 3 months. The fair tolerability of the drug and low rate of dyskinesias and other complications were demonstrated. In conclusion, the study has shown that rasagiline effectively reduces the off-time duration as well as the disability in off- and on-time and optimizes levodopa efficacy at the routine clinical practice setting. PMID:21389939

Levin, O S; Bo?ko, A N; Ivanov, A K

2010-01-01

359

The efficacy of a school-based caries preventive program: a 4-year study.  

PubMed

This longitudinal study aimed at testing the efficacy of a school-based caries preventive program, by comparing dental caries status of two groups, a study group (436 children) and a control group (420 children) over a period of 4 years. The study group received a preventive program which consisted of intensive oral hygiene instructions sessions, and supervised daily tooth brushing using fluoridated tooth paste in schools. The control group received only oral hygiene instructions sessions. Annual dental examination to record dental caries status, using Decayed Missed Filled Teeth Index (DMFT) and deft, was conducted for both groups over a period of 4 years. At the end of the fourth year the efficacy of the program was tested by comparing the DMFT and deft indices for the two groups using Pearson chi-square test and Cochran-Mantel-Haenzele test. The level of significance was set at P < 0.05. The results after 4 years showed that the caries status of the children in the study group was better than that of the control group. The difference was statistically significant (P-value 0.001). The estimates of relative risk values also showed that children in the control group are 3.1 and 6.4 times at higher risk of having dental caries than those in the study group for age group 12 and 6 respectively. This study proves that supervised daily tooth brushing using fluoridated toothpaste is successful in controlling dental caries in children. PMID:16451437

Al-Jundi, S H; Hammad, M; Alwaeli, H

2006-02-01

360

Critical review of oral drug treatments for diabetic neuropathic pain-clinical outcomes based on efficacy and safety data from placebo-controlled and direct comparative studies  

Microsoft Academic Search

The present review aims to evaluate the efficacy and safety of a selection of oral treatments for the management of painful diabetic neuropathy. A literature review was conducted retrieving placebo-controlled and direct comparative studies with a selection of oral treatments for painful diabetic neuropathy. All studies were analyzed with regard to efficacy and tolerability. Efficacy was evaluated as the percentage

Hugo Adriaensen; Léon Plaghki; Chantal Mathieu; Alfred Joffroy; Kris Vissers

2005-01-01

361

CTLA-4 blockade in tumor models: an overview of preclinical and translational research  

PubMed Central

Cytotoxic T lymphocyte antigen-4 (CTLA-4) is a key negative regulator of T cell activation. A complex integration of positive and negative co-stimulatory signals in the well-defined B7:CD28/CTLA-4 pathway modulates the generation and maintenance of immune responses. Inhibiting negative regulation through binding of CTLA-4 has been shown to promote stimulation of adaptive immunity and potentiation of T cell activation. CTLA-4-blocking antibodies have demonstrated efficacy in various murine malignancy models when administered as monotherapy; additionally, they have shown synergistic anti-tumor activity when utilized with other agents, such as vaccines, chemotherapy, and radiation. Preclinical studies have supported the rationale for current clinical development of anti-CTLA-4 antibodies, including ipilimumab and tremelimumab, as novel therapeutic strategies to augment anti-tumor immunity in cancer. Both ipilimumab and tremelimumab have been evaluated extensively in melanoma; notably, ipilimumab was recently approved as monotherapy for the treatment of advanced melanoma. Tremelimumab is currently undergoing evaluation in phase II trials as monotherapy in melanoma and malignant mesothelioma, while ipilimumab is under clinical investigation in phase II and III trials in various tumor types, including in melanoma, prostate, and lung cancers as monotherapy and with other therapeutic modalities, such as chemotherapy and radiation. In this review, we will provide a detailed overview of preclinical advances that have delineated many features of CTLA-4 and have helped define its role in T cell response. We will also highlight clinical application of anti-CTLA-4 therapy in cancer and describe knowledge gaps that future studies may address. PMID:23390376

Grosso, Joseph F.; Jure-Kunkel, Maria N.

2013-01-01

362

Photoacoustic tomography of vascular therapy in a preclinical mouse model of colorectal carcinoma  

NASA Astrophysics Data System (ADS)

Vascular therapy in oncology exploits the differences between normal blood vessels and abnormal tumour neoangiogenesis to selectively target cancer. For optimal treatment efficacy, and translation of novel compounds, the response of the tumour vasculature needs to be assessed. Photoacoustic tomography (PAT) is capable of this as it provides highly spatially resolved 3D images of vascular networks in biological tissue to cm depths. In preclinical models of cancer this is sufficient to encompass entire subcutaneous tumours, and can therefore be used to evaluate pharmacological intervention directed at the vasculature. In this study the vascular disrupting agent OXi4503 was used to treat subcutaneous tumour mouse models of two human colorectal carcinoma tumour types (SW1222, LS174T) at a range of concentrations (40mg/kg, 10mg/kg, 1mg/kg and sham dose control). The characteristic destruction of tumour vasculature caused by OXi4503 was observed by PAT and confirmed ex vivo via histology. Differences observed between the two tumour types assessed demonstrate the importance of tumour microenvironment and pathophysiology on response to therapy. Differential response to different doses of OXi4503 was observed, with outward tumour growth only seen once entire tumour viability had been re-established; this demonstrates the potential of PAT to act as a biomarker of response for the translation of novel anti-vascular compounds and also within the clinic. This study shows clearly that PAT can accurately assess the time course of drug action and relapse of pharmacodynamic effect in preclinical models of cancer and the important translational prospects for vascular targeted tumour therapies.

Johnson, S. P.; Ogunlade, O.; Zhang, E.; Laufer, J.; Rajkumar, V.; Pedley, R. B.; Beard, P.

2014-03-01

363

Towards combinatorial targeted therapy in melanoma: From pre-clinical evidence to clinical application (Review)  

PubMed Central

Over the last few years, clinical trials with BRAF and mitogen-activated protein/extracellular signal-regulated kinase (MEK) inhibitors have shown significant clinical activity in melanoma, but only a fraction of patients respond to these therapies, and development of resistance is frequent. This has prompted a large set of preclinical studies looking at several new combinatorial approaches of pathway- or target-specific inhibitors. At least five main drug association strategies have been verified in vitro and in preclinical models. The most promising include: i) vertical targeting of either MEK or phosphoinositide-3 kinase (PI3K)/mammalian target of rapamycin (mTOR) pathways, or their combined blockade; ii) association of receptor tyrosine kinases (RTKs) inhibitors with other pro-apoptotic strategies; iii) engagement of death receptors in combination with MEK-, mTOR/PI3K-, histone deacetylase (HDAC)-inhibitors, or with anti-apoptotic molecules modulators; iv) strategies aimed at blocking anti-apoptotic proteins belonging to B-cell lymphoma (Bcl-2) or inhibitors of apoptosis (IAP) families associated with MEK/BRAF/p38 inhibition; v) co-inhibition of other molecules important for survival [proteasome, HDAC and Signal transducers and activators of transcription (Stat)3] and the major pathways activated in melanoma; vi) simultaneous targeting of multiple anti-apoptotic molecules. Here we review the anti-melanoma efficacy and mechanism of action of the above-mentioned combinatorial strategies, together with the potential clinical application of the most promising studies that may eventually lead to therapeutic benefit. PMID:24920406

GRAZIA, GIULIA; PENNA, ILARIA; PEROTTI, VALENTINA; ANICHINI, ANDREA; TASSI, ELENA

2014-01-01

364

A study to evaluate the field efficacy of ivermectin, fenbendazole and pyrantel pamoate, with preliminary observations on the efficacy of doramectin, as anthelmintics in horses.  

PubMed

The efficacy of ivermectin, fenbendazole, pyrantel pamoate and doramectin was evaluated under field conditions at 2 sites in the Free State Province of South Africa. The study involved 25 horses at each site, divided into 5 groups of equal size. Ivermectin, fenbendazole and pyrantel pamoate were administered orally at doses of 0.2, 10 and 19 mg/kg respectively. Doramectin was administered by intramuscular injection at a dose of 0.2 mg/kg. Treatment efficacy was based on the mean faecal egg count reduction 14 days post treatment. At site A a faecal egg count reduction of 100% was found after treatment with ivermectin, fenbendazole and doramectin. A 96.1% reduction was found after treatment with pyrantel pamoate. At site B ivermectin and doramectin produced a 100% reduction in faecal egg counts, fenbendazole produced an 80.8% reduction and pyrantel pamoate a 94.1% reduction. Doramectin produced a 100% reduction in faecal egg counts at both sites, despite not being registered for use in horses. In addition, the results indicated reduced efficacy of fenbendazole at site B, which suggested benzimidazole resistance. Larval cultures showed that cyathostomes accounted for between 86 and 96% of pre-treatment parasite burdens at both sites. Other helminths identified in the faecal samples were Strongylus spp. and Trichostrongylus axei. PMID:11205161

Davies, J A; Schwalbach, L M

2000-09-01

365

A Comparison of the ?2/3/5 Selective Positive Allosteric Modulators L-838,417 and TPA023 in Preclinical Models of Inflammatory and Neuropathic Pain  

PubMed Central

GABAA receptors containing ?2/3 subunits are current targets in the battle to develop new pain medications, as they are expressed in the spinal cord where increasing inhibitory drive should result in analgesia. However, this approach is prone to a range of side effects including sedation, cognitive impairment, and abuse as a consequence of the widespread influence of GABA. The ability to make subtype selective low-efficacy benzodiazepine compounds, which potentiate the action of GABA at specific ? subunits, has the potential to reduce this side effect profile. In this study, we have investigated the effects of the medium-efficacy positive allosteric modulator (PAM) L-838,417 and the low-efficacy PAM TPA023 in a number of preclinical inflammatory and neuropathic pain models. We conclude that either the higher level of efficacy at ?2/3 or efficacy at ?5 is required for compounds to have a significant analgesic effect in a range of models, and, therefore, although the side-effect profile of compounds can be reduced compared to typical benzodiazepines, it is unlikely that it can be completely eliminated. PMID:22162674

Nickolls, Sarah; Mace, Hannah; Fish, Rebecca; Edye, Michelle; Gurrell, Rachel; Ivarsson, Magnus; Pitcher, Tom; Tanimoto-Mori, Sachi; Richardson, Denise; Sweatman, Catherine; Nicholson, Janet; Ward, Cameron; Jinks, John; Bell, Christine; Young, Kimberly; Rees, Huw; Moss, Andrew; Kinloch, Ross; McMurray, Gordon

2011-01-01

366

Science teaching self-efficacy in a primary school: A case study  

Microsoft Academic Search

Bandura's theory of self-efficacy predicts that teachers with high, self-efficacy should persist longer, provide a greater\\u000a academic focus in child-centred classrooms and exhibit different types of feedback than teachers who have lower self-efficacy.\\u000a This paper reports on the science teaching self-efficacy in a group of teachers at a state primary school. The research was\\u000a conducted in two stages using firstly

Jenny de Laat; James J. Watters

1995-01-01

367

Development of an Aotus nancymaae model for Shigella Vaccine immunogenicity and efficacy studies.  

PubMed

Several animal models exist to evaluate the immunogenicity and protective efficacy of candidate Shigella vaccines. The two most widely used nonprimate models for vaccine development include a murine pulmonary challenge model and a guinea pig keratoconjunctivitis model. Nonhuman primate models exhibit clinical features and gross and microscopic colonic lesions that mimic those induced in human shigellosis. Challenge models for enterotoxigenic Escherichia coli (ETEC) and Campylobacter spp. have been successfully developed with Aotus nancymaae, and the addition of a Shigella-Aotus challenge model would facilitate the testing of combination vaccines. A series of experiments were designed to identify the dose of Shigella flexneri 2a strain 2457T that induces an attack rate of 75% in the Aotus monkey. After primary challenge, the dose required to induce an attack rate of 75% was calculated to be 1 × 10(11) CFU. Shigella-specific immune responses were low after primary challenge and subsequently boosted upon rechallenge. However, preexisting immunity derived from the primary challenge was insufficient to protect against the homologous Shigella serotype. A successive study in A. nancymaae evaluated the ability of multiple oral immunizations with live-attenuated Shigella vaccine strain SC602 to protect against challenge. After three oral immunizations, animals were challenged with S. flexneri 2a 2457T. A 70% attack rate was demonstrated in control animals, whereas animals immunized with vaccine strain SC602 were protected from challenge (efficacy of 80%; P = 0.05). The overall study results indicate that the Shigella-Aotus nancymaae challenge model may be a valuable tool for evaluating vaccine efficacy and investigating immune correlates of protection. PMID:24595138

Gregory, Michael; Kaminski, Robert W; Lugo-Roman, Luis A; Galvez Carrillo, Hugo; Tilley, Drake Hamilton; Baldeviano, Christian; Simons, Mark P; Reynolds, Nathanael D; Ranallo, Ryan T; Suvarnapunya, Akamol E; Venkatesan, Malabi M; Oaks, Edwin V

2014-05-01

368

Development of an Aotus nancymaae Model for Shigella Vaccine Immunogenicity and Efficacy Studies  

PubMed Central

Several animal models exist to evaluate the immunogenicity and protective efficacy of candidate Shigella vaccines. The two most widely used nonprimate models for vaccine development include a murine pulmonary challenge model and a guinea pig keratoconjunctivitis model. Nonhuman primate models exhibit clinical features and gross and microscopic colonic lesions that mimic those induced in human shigellosis. Challenge models for enterotoxigenic Escherichia coli (ETEC) and Campylobacter spp. have been successfully developed with Aotus nancymaae, and the addition of a Shigella-Aotus challenge model would facilitate the testing of combination vaccines. A series of experiments were designed to identify the dose of Shigella flexneri 2a strain 2457T that induces an attack rate of 75% in the Aotus monkey. After primary challenge, the dose required to induce an attack rate of 75% was calculated to be 1 × 1011 CFU. Shigella-specific immune responses were low after primary challenge and subsequently boosted upon rechallenge. However, preexisting immunity derived from the primary challenge was insufficient to protect against the homologous Shigella serotype. A successive study in A. nancymaae evaluated the ability of multiple oral immunizations with live-attenuated Shigella vaccine strain SC602 to protect against challenge. After three oral immunizations, animals were challenged with S. flexneri 2a 2457T. A 70% attack rate was demonstrated in control animals, whereas animals immunized with vaccine strain SC602 were protected from challenge (efficacy of 80%; P = 0.05). The overall study results indicate that the Shigella-Aotus nancymaae challenge model may be a valuable tool for evaluating vaccine efficacy and investigating immune correlates of protection. PMID:24595138

Gregory, Michael; Lugo-Roman, Luis A.; Galvez Carrillo, Hugo; Tilley, Drake Hamilton; Baldeviano, Christian; Simons, Mark P.; Reynolds, Nathanael D.; Ranallo, Ryan T.; Suvarnapunya, Akamol E.; Venkatesan, Malabi M.; Oaks, Edwin V.

2014-01-01

369

A prospective study comparing the efficacy and safety of two sublingual birch allergen preparations  

PubMed Central

Background SUBLIVAC FIX Birch (SUB-B) is a liquid oral preparation of Betula verrucosa pollen extract for the treatment of allergic rhinitis/rhinoconjuctivitis induced by birch pollen. The major allergen content of SUB-B and Staloral Birch (Stal-B) have been shown to be comparable. In order to compare the clinical efficacy and safety of both products, the present study was designed to investigate efficacy of treatment with SUB-B compared to Stal-B by means of reduction in allergy symptoms assessed by a titrated nasal provocation test (TNPT) in subjects suffering from IgE mediated allergy complaints triggered by birch pollen. Methods A prospective, randomized, open, blinded endpoint (PROBE), controlled, single-centre study in 74 birch allergic adults was performed. Treatment consisted of either SUB-B (10,000 AUN/ml) or Stal-B (initial phase 10 I.R./ml and maintenance phase 300 I.R./ml) for 16–20 weeks at maintenance dose. The primary efficacy outcome was defined by the difference in change of the TNPT-threshold dose between the two treatment groups at baseline and after completion of treatment. Secondary outcomes included determination of birch pollen specific IgE and IgG levels, safety lab and ECG. During the first 30 days of treatment, subjects were requested to fill out a diary concerning compliance with study medication, occurrence of AEs and the use of concomitant medication. Results Analysis of the primary efficacy parameter showed that the percentage of subjects showing a beneficial treatment effect was similar in both treatment groups, 33.3% for SUB-B vs. 31.4% for Stal-B in the intention to treat population. Evaluation of the immunologic response, showed that treatment with SUB-B and Stal-B induced similar increases (approximately 2 times) in IgE, IgG and IgG4 specific for Bet v 1. In total, 143 related adverse events (AEs) were reported. The majority of the AEs was of mild intensity. The same pattern of AEs was observed for both products. No clinically relevant changes in other safety parameters, such as safety laboratory parameters, vital signs, physical examination and ECGs were observed. Conclusion Taken together, treatment with both products was effective by means of reduction in allergic symptoms during a TNPT. In addition, safety analysis revealed a good tolerability of both SLIT extracts. PMID:25097754

2014-01-01

370

Non-interventional study evaluating efficacy and tolerability of rifaximin for treatment of uncomplicated diverticular disease.  

PubMed

Patients with symptomatic uncomplicated diverticular disease represent a spectrum of patients who report recurrent abdominal symptoms, however are lacking substantial colonic inflammation in contrast to patients with acute diverticulitis. This non-interventional study investigated the efficacy and tolerability of rifaximin, a broad-spectrum poorly absorbable antibiotic, in cyclic treatment of these patients. Adult patients with uncomplicated diverticular disease in care of physicians in private practice intended to be treated with rifaximin were included. Patients with acute diverticulitis and symptoms suggestive of more severe intestinal inflammation were excluded. Data of 1,003 patients treated in cycles of 7-10 days per month over a period of 3 months were evaluated. In total, 75?% of patients had more than three episodes of symptoms in the last year before inclusion in the study. However, two-third of patients did not receive any treatment before. Over the 3-month treatment period with rifaximin, all assessed symptoms of diverticular disease, such as abdominal pain, diarrhoea and flatulence, improved significantly. There was an overall good compliance to the scheme of cyclic drug administration of rifaximin. During the study, 24 adverse events in 20 patients were recorded, of which 6 adverse events showed a causal relationship to the use of rifaximin (0.6?%). We conclude that cyclic rifaximin shows good clinical efficacy and tolerability in patients with symptomatic uncomplicated diverticular disease treated in a routine private practice outpatient setting. PMID:24240607

Stallinger, Sylvia; Eller, Norbert; Högenauer, Christoph

2014-01-01

371

A prospective study to assess the efficacy and patient tolerance of three bowel preparations for colonoscopy.  

PubMed

The adherence to the required clear liquid diet and a high-volume bowel cleansing solution prior to colonoscopy often leads to poor patient compliance and inadequate exams. This study evaluated the efficacy and patient tolerance of three bowel preparation regimens prior to colonoscopy. One hundred fourteen patients were randomized to one of three preparations. Group 1 was assigned a clear liquid diet/magnesium citrate and bisacodyl prep; group 2 was assigned to receive a diet kit/magnesium citrate and bisacodyl prep; and group 3 received a diet kit/polyethylene glycol electrolyte prep. The adequacy of bowel preparation was graded by the endoscopists performing the procedures. The preparations were rated by patients for tolerance, compliance, and side effects. The three methods of preparation did not prove to be significantly different in regards to efficacy of colon cleansing or patient tolerability. There was also no difference in compliance between the three regimens. There were no reported side effects in any of the study groups. This study suggests that a low-residue diet kit, given in conjunction with polyethylene glycol electrolyte or magnesium citrate and bisacodyl, produces adequate colon cleansing and patient tolerability. PMID:16974167

Rapier, Roderick; Houston, Carmela

2006-01-01

372

Efficacy and safety of acupuncture for chronic dizziness: study protocol for a randomized controlled trial  

PubMed Central

Background Dizziness is one of the most challenging symptoms in medicine. No medication for dizziness in current use has well-established curative or prophylactic value or is suitable for long-term palliative use. Unconventional remedies, such as acupuncture, should be considered and scientifically evaluated. However, there has been relatively little evidence in randomized controlled clinical trials on acupuncture to treat chronic dizziness. The aim of our study is to evaluate the efficacy and safety of acupuncture in patients with dizziness. Methods/Design This trial is a randomized, single-blind, controlled study. A total of 80 participants will be randomly assigned to two treatment groups receiving acupuncture and sham acupuncture treatment, respectively, for 4 weeks. The primary outcome measures are the Dizziness Handicap Inventory (DHI) and the Vertigo Symptom Scale (VSS). Treatment will be conducted over a period of 4 weeks, at a frequency of two sessions per week. The assessment is at baseline (before treatment initiation), 4 weeks after the first acupuncture session, and 8 weeks after the first acupuncture session. Discussion The results from this study will provide clinical evidence on the efficacy and safety of acupuncture in patients with chronic dizziness. Trial registration International Standard Randomized Controlled Trial Number Register: ISRCTN52695239 PMID:24330810

2013-01-01

373

Resource loss, self-efficacy, and family support predict posttraumatic stress symptoms: a 3-year study of earthquake survivors.  

PubMed

Background and Objectives: Social support and self-efficacy are regarded as coping resources that may facilitate readjustment after traumatic events. The 2009 Cinchona earthquake in Costa Rica serves as an example for such an event to study resources to prevent subsequent severity of posttraumatic stress symptoms. Design: At Time 1 (1-6 months after the earthquake in 2009), N = 200 survivors were interviewed, assessing resource loss, received family support, and posttraumatic stress response. At Time 2 in 2012, severity of posttraumatic stress symptoms and general self-efficacy beliefs were assessed. Methods: Regression analyses estimated the severity of posttraumatic stress symptoms accounted for by all variables. Moderator and mediator models were examined to understand the interplay of received family support and self-efficacy with posttraumatic stress symptoms. Results: Baseline posttraumatic stress symptoms and resource loss (T1) accounted for significant but small amounts of the variance in the severity of posttraumatic stress symptoms (T2). The main effects of self-efficacy (T2) and social support (T1) were negligible, but social support buffered resource loss, indicating that only less supported survivors were affected by resource loss. Self-efficacy at T2 moderated the support-stress relationship, indicating that low levels of self-efficacy could be compensated by higher levels of family support. Receiving family support at T1 enabled survivors to feel self-efficacious, underlining the enabling hypothesis. Conclusions: Receiving social support from relatives shortly after an earthquake was found to be an important coping resource, as it alleviated the association between resource loss and the severity of posttraumatic stress response, compensated for deficits of self-efficacy, and enabled self-efficacy, which was in turn associated with more adaptive adjustment 3 years after the earthquake. PMID:25130373

Warner, Lisa Marie; Gutiérrez-Doña, Benicio; Villegas Angulo, Maricela; Schwarzer, Ralf

2014-09-17

374

The efficacy of RNAi in the study of the plant cytoskeleton.  

PubMed

Recent studies on a variety of organisms point to the ubiquity of RNA interference (RNAi) as a means to induce a gene-specific block to translation. RNAi has gained popularity in the last few years in the study of a number of problems in development. In this review, we highlight recent findings with RNAi using several different kinds of animals and fungi, and we show how these responses parallel cosuppression effects described in plants nearly a decade earlier. We then point to the efficacy of RNAi in studying minor and regulatory components of the plant cytoskeleton, and we highlight some recent studies using this approach with the water fern, Marsilea vestita. PMID:11762377

Klink, V P; Wolniak, S M

2000-12-01

375

Efficacy of 5% Imiquimod Cream on Vulvar Intraepithelial Neoplasia in Korea: Pilot Study  

PubMed Central

Background Various therapeutic options, including surgery, electrocautery, cryotherapy, 5-fluorouracil treatment, laser therapy, radiotherapy, photodynamic therapy, and interferon-?/? injection, have been employed to treat vulvar intraepithelial neoplasia (VIN) with varying degrees of success. To truly cure VIN, human papillomavirus elimination is considered important. Objective To investigate the efficacy of 5% imiquimod cream used to treat VIN in Korean patients Methods We performed a prospective, uncontrolled, observational study. Nine patients with histologically confirmed VIN applied 5% imiquimod cream to their vulvar lesions three to five times a week until a clinical response was apparent. All lesions were photo-documented, and therapeutic efficacy was assessed in terms of local adverse effects lesion number, size, and hyperpigmentation. Results The mean treatment duration was 30.2 months, and the median follow-up period after therapy completion was 30 months. Of the nine patients recruited, six (66.6%) experienced complete responses (CR) or partial responses (PR). Hyperpigmented patches in the VIN lesions were evident in five subjects (55.6%), and all experienced either CR or PR. Only three patients (33.3%) suffered from local adverse effects, which were relieved after temporary suspension of therapy, and better outcomes were attained ultimately. Conclusion The imiquimod cream was more efficacious when used to treat VIN of the hyperpigmented type compared with lesions lacking pigmentation. The unifocal nature of a lesion and the development of local adverse effects are useful factors when imiquimod cream is prescribed. However, although the cream is convenient and effective, regional resistance may develop, and close follow-up is essential because VIN may become malignant.

Kim, Jeong-Min; Lee, Hyun-Joo; Kim, Su-Han; Kim, Hoon-Soo; Ko, Hyun-Chang; Kim, Byung-Soo; Kim, Moon-Bum

2015-01-01

376

Career interest, self-efficacy, and perception in undecided and nursing undergraduate students: a quantitative study.  

PubMed

Career choice variables of career interest, self-efficacy, and perception were chosen based upon Social Cognitive Career Theory concepts for study between nursing and undecided undergraduate student groups. Components of the Career Search Questionnaire and Perceptions of Professional Nursing instruments were combined and adapted to form the Career Choice Survey for use in this research. This web-based survey totaling 40 questions was sent to 577 undergraduate students with a 12% response rate (N=68). Due to the need to increase nursing recruitment and retention, hypotheses were developed that distinguish if any relationship existed between groups. Findings of this quantitative study resulted in statistically significant results on two of the three variable hypotheses (p=.006 for career interest, p=.002 for self-efficacy, p=.395 for perception), aligning with previous research and provide insight into the change in nursing perception. Overall, scores for each subscale were encouraging to current nurses and expected from undecided students. Implications for practice include increases in accurate nursing portrayal in the media and early career counseling to younger populations. Nurse educators can further research in career choice with focus on continuing education for current nurses and recruitment of young nursing hopefuls. PMID:25218036

Fillman, Valentina M

2015-01-01

377

Efficacy of Agnikarma over the padakanistakam (little toe) and Katibasti in Gridhrasi: A comparative study  

PubMed Central

Background and Objectives: Gridhrasi (Sciatica) is one of the Vatavyadhi which is caused by aggravated Vata dosha. This disease is characterized by ruja (pain) in the waist, back, thigh, knee and calf regions along the course of sciatic nerve. In spite of the different types of treatment modalities mentioned in ancient and modern medical sciences, they have some or the other shortcomings and drawbacks. Considering all these, the present study was taken up with the objective of evaluating the efficacy of Agnikarma (treatment done with cauterization) over the padakanistakam (little toe) in the management of Gridhrasi. To consider the significance of the method of Agnikarma, the efficacy of Katibasti in the management of Gridhrasi which has been established in the previous work was also studied. Materials and Methods: The study was performed after obtaining Ethics Committee approval and patients? written informed consent. Forty cases presenting with classical features of Gridhrasi (Sciatica) due to lumbar intervertebral disc prolapse were selected. The management of Gridhrasi by Agnikarma and Katibasti was conducted by including the patients in two groups, namely Group A (study group) and Group B (control group). The data were collected and the observations were made before the treatment, on 8th day, 15th day and on 22nd day of the treatment. The data obtained from the results were subjected for statistical analysis and conclusions were drawn. Results: There was a significant reduction in the parameters, pain (P < 0.01) and straight-leg raising (SLR) test (P < 0.01), of the study group compared to the control group (P < 0.01). Pain was assessed through Numerical Pain Analogue Scale. After the treatment with Agnikarma, the pain was totally relieved in 80% of cases. It was reduced to moderate degree in 20% of cases and in 95% of cases, SLR test became negative. After the treatment with Katibasti, the pain was totally relieved in 50% of cases. It was reduced to moderate degree in 20% and to mild degree in 25% of cases. In 60% of cases, SLR test became negative. However, changes in the radiological findings were not found in both the methods of management. Analysis of overall effect of treatment in the present study reveals that Agnikarma was Both the procedures were conducted in to that of Katibasti. Conclusions: The management of Gridhrasi by Agnikarma was more efficacious as compared with Katibasti in reducing pain. However, there were no radiological changes produced by both the methods of treatment. Further studies may be conducted by future scholars by taking more samples with more number of sittings. PMID:21455450

Bali, Yogitha; Vijayasarathi, R; Ebnezar, John; Venkatesh, BA

2010-01-01

378

Phase II Genomics Study of Ixabepilone as Neoadjuvant Treatment for Breast Cancer  

Microsoft Academic Search

Purpose This phase II study evaluated the efficacy and safety of ixabepilone as neoadjuvant therapy for invasive breast cancer not amenable to breast conservation surgery. Gene expression studies were undertaken using genes that were identified as potentially associated with sensitivity\\/ resistance to ixabepilone in prior preclinical investigations. Patients and Methods Patients with invasive breast cancer 3 cm were eligible. Ixabepilone

Milvia Zambetti; Antoni Llombart-Cussac; Georgy Manikhas; Ernst Kubista; Gunther G. Steger; Anatoly Makhson; Sergei Tjulandin; Heinz Ludwig; Mark Verrill; Eva Ciruelos; Suzanne Egyhazi; Li-An Xu; Kim E. Zerba; Hyerim Lee; Edwin Clark; Susan Galbraith

2010-01-01

379

Chemical Abstracts coverage of the preclinical sciences journal literature.  

PubMed

This study examines Chemical Abstracts (CA) coverage of the journal literature cited by researchers from preclinical science departments affiliated with medical schools. Using references from 70 dissertations written between 1973 and 1977 in the fields of anatomy, biochemistry, immunology, microbiology, pathology, pharmacology, and physiology, coverage of journal articles was studied. Approximately 57% of the cited literature was covered. Biochemistry (83.5%), pharmacology (80.4%), and microbiology (76.2%) were covered the best while pathology (27.8%) was covered the worst. Coverage of anatomy (55.4%), immunology (40.1%), and physiology (42.4%) was dependent upon the research being conducted. With the advent of multidata base searching, Chemical Abstracts should be considered as a source of references for preclinical science researchers. PMID:7068787

Poyer, R K

1982-02-01

380

The efficacy of methylprednisolone in the treatment of hyperemesis gravidarum: A randomized, double-blind, controlled study  

Microsoft Academic Search

Objective: The study compared the efficacy of methylprednisolone with that of promethazine for the treatment of hyperemesis gravidarum. Study Design: Patients with a normal-appearing intrauterine pregnancy of ?16 weeks’ gestation with hyperemesis gravidarum (persistent vomiting and large ketonuria despite outpatient therapy) were admitted to the hospital for continuous intravenous hydration and offered participation in the study. Patients meeting study criteria

Hamid R. Safari; Michael J. Fassett; Irene C. Souter; Owaidah M. Alsulyman; T. Murphy Goodwin

1998-01-01

381

Translational potential of preclinical trials of neuroprotection through pharmacotherapy for spinal cord injury.  

PubMed

There is a need to enhance the pipeline of discovery and evaluation of neuroprotective pharmacological agents for patients with spinal cord injury (SCI). Although much effort and money has been expended on discovering effective agents for acute and subacute SCI, no agents that produce major benefit have been proven to date. The deficiencies of all aspects of the pipeline, including the basic science input and the clinical testing output, require examination to determine remedial strategies. Where has the neuroprotective/pharmacotherapy preclinical process failed and what needs to be done to achieve success? These are the questions raised in the present review, which has 2 objectives: 1) identification of articles that address issues related to the translational readiness of preclinical SCI pharmacological therapies; and 2) examination of the preclinical studies of 5 selected agents evaluated in animal models of SCI (including blunt force trauma, penetrating trauma, or ischemia). The 5 agents were riluzole, glyburide, magnesium sulfate, nimodipine, and minocycline, and these were selected because of their promise of translational readiness as determined by the North American Clinical Trials Network Consortium. The authors found that there are major deficiencies in the effort that has been extended to coordinate and conduct preclinical neuroprotection/pharmacotherapy trials in the SCI field. Apart from a few notable exceptions such as the NIH effort to replicate promising strategies, this field has been poorly coordinated. Only a small number of articles have even attempted an overall evaluation of the neuroprotective/pharmacotherapy agents used in preclinical SCI trials. There is no consensus about how to select the agents for translation to humans on the basis of their preclinical performance and according to agreed-upon preclinical performance criteria. In the absence of such a system and to select the next agent for translation, the Consortium has developed a Treatment Strategy Selection Committee, and this committee selected the most promising 5 agents for potential translation. The results show that the preclinical work on these 5 agents has left numerous gaps in knowledge about their preclinical performance and confirm the need for significant changes in preclinical neuroprotection/pharmacotherapy trials in SCI. A recommendation is made for the development and validation of a preclinical scoring system involving worldwide experts in preclinical and clinical SCI. PMID:22985382

Tator, Charles H; Hashimoto, Robin; Raich, Annie; Norvell, Daniel; Fehlings, Michael G; Harrop, James S; Guest, James; Aarabi, Bizhan; Grossman, Robert G

2012-09-01

382

The Current State of Preclinical Prostate Cancer Animal Models  

PubMed Central

Prostate cancer continues to be a major cause of morbidity and mortality in men around the world. The field of prostate cancer research continues to be hindered by the lack of relevant preclinical models to study tumorigenesis and to further development of effective prevention and therapeutic strategies. The Prostate Cancer Foundation held a Prostate Cancer Models Working Group (PCMWG) Summit on August 6th and 7th, 2007 to address these issues. The PCMWG reviewed the state of prostate cancer preclinical models and identified the current limitations of cell line, xenograft and genetically engineered mouse models that have hampered the transition of scientific findings from these models to human clinical trials. In addition the PCMWG identified administrative issues that inhibit the exchange of models and impede greater interactions between academic centers and these centers with industry. The PCMWG identified potential solutions for discovery bottlenecks that include: (1) insufficient number of models with insufficient molecular and biologic diversity to reflect human cancer, (2) a lack of understanding of the molecular events that define tumorigenesis, (3) a lack of tools for studying tumor–host interactions, (4) difficulty in accessing model systems across institutions, and (5) addressing why preclinical studies appear not to be predictive of human clinical trials. It should be possible to apply the knowledge gained molecular and epigenetic studies to develop new cell lines and models that mimic progressive and fatal prostate cancer and ultimately improve interventions. PMID:18213636

Pienta, Kenneth J.; Abate-Shen, Cory; Agus, David B.; Attar, Ricardo M.; Chung, Leland W.K.; Greenberg, Norman M.; Hahn, William C.; Isaacs, John T.; Navone, Nora M.; Peehl, Donna M.; Simons, Jonathon W.; Solit, David B.; Soule, Howard R.; VanDyke, Terry A.; Weber, Michael J.; Wu, Lily; Vessella, Robert L.

2013-01-01

383

Comparative anti-microbial efficacy of Azadirachta indica irrigant with standard endodontic irrigants: A preliminary study  

PubMed Central

Objective: The anti-microbial efficacy of 2.5% sodium hypochlorite (SHC) and 0.2% chlorhexidine gluconate were compared with an experimental irrigant formulated from the Neem tree, Azadirachta indica A. Juss. Materials and Methods: A sample of 36 single rooted anterior teeth with periapical radiolucency and absence of response to vitality tests that required root canal treatment were selected for this study. The test irrigants and their combinations were assigned to five different groups and saline served as the control. Access cavities were prepared using an aseptic technique and samples collected for both anaerobic culture and Gram stained smears, followed by irrigation and sample collection again. The number of organisms were expressed in colony forming units/ml after 72 h of incubation; the smears were analyzed for their microbial loads and tissue clearance and assessed as per defined criteria. Results: Our results found the maximum reduction in microbial loads, when analyzed by culture method, with a combination of SHC and the experimental neem irrigant. Maximum tissue clearance on the Gram Stained smears was also found with the same combination. Conclusion: Neem irrigant has anti-microbial efficacy and can be considered for endodontic use. PMID:24778508

Dutta, Arindam; Kundabala, Mala

2014-01-01

384

Paliperidone ER in the Treatment of Borderline Personality Disorder: A Pilot Study of Efficacy and Tolerability.  

PubMed

Antipsychotics are recommended for the treatment of impulsive dyscontrol and cognitive perceptual symptoms of borderline personality disorder (BPD). Three reports supported the efficacy of oral risperidone on BPD psychopathology. Paliperidone ER is the metabolite of risperidone with a similar mechanism of action, and its osmotic release reduces plasmatic fluctuations and antidopaminergic effects. The aim of this study is to evaluate efficacy and safety of paliperidone ER in BPD patients. 18 outpatients with a DSM-IV-TR diagnosis of BPD were treated for 12 weeks with paliperidone ER (3-6?mg/day). They were assessed at baseline, week 4, and week 12, using the CGI-Severity item, the BPRS, the HDRS, the HARS, the SOFAS, the BPD Severity Index (BPDSI), and the Barratt Impulsiveness Scale (BIS-11). Adverse events were evaluated with the DOTES. Paliperidone ER was shown to be effective and well tolerated in reducing severity of global symptomatology and specific BPD symptoms, such as impulsive dyscontrol, anger, and cognitive-perceptual disturbances. Results need to be replicated in controlled trials. PMID:21826264

Bellino, Silvio; Bozzatello, Paola; Rinaldi, Camilla; Bogetto, Filippo

2011-01-01

385

Paliperidone ER in the Treatment of Borderline Personality Disorder: A Pilot Study of Efficacy and Tolerability  

PubMed Central

Antipsychotics are recommended for the treatment of impulsive dyscontrol and cognitive perceptual symptoms of borderline personality disorder (BPD). Three reports supported the efficacy of oral risperidone on BPD psychopathology. Paliperidone ER is the metabolite of risperidone with a similar mechanism of action, and its osmotic release reduces plasmatic fluctuations and antidopaminergic effects. The aim of this study is to evaluate efficacy and safety of paliperidone ER in BPD patients. 18 outpatients with a DSM-IV-TR diagnosis of BPD were treated for 12 weeks with paliperidone ER (3–6?mg/day). They were assessed at baseline, week 4, and week 12, using the CGI-Severity item, the BPRS, the HDRS, the HARS, the SOFAS, the BPD Severity Index (BPDSI), and the Barratt Impulsiveness Scale (BIS-11). Adverse events were evaluated with the DOTES. Paliperidone ER was shown to be effective and well tolerated in reducing severity of global symptomatology and specific BPD symptoms, such as impulsive dyscontrol, anger, and cognitive-perceptual disturbances. Results need to be replicated in controlled trials. PMID:21826264

Bellino, Silvio; Bozzatello, Paola; Rinaldi, Camilla; Bogetto, Filippo

2011-01-01