Research Methods in Life Sciences Commons^™

Harnessing Opportunities In Non-Animal Asthma Research For A 21st-Century Science, Gemma L. Buckland

Experimentation Collection

The incidence of asthma is on the increase and calls for research are growing, yet asthma is a disease that scientists are still trying to come to grips with. Asthma research has relied heavily on animal use; however, in light of increasingly robust in vitro and computational models and the need to more fully incorporate the ‘Three Rs’ principles of Replacement, Reduction and Refinement, is it time to reassess the asthma research paradigm? Progress in non-animal research techniques is reaching a level where commitment and integration are necessary. Many scientists believe that progress in this field rests on linking disciplines …

Behavior And Physiology Of Hermit Crabs During Burial: Shell Abandonment And Lactate Accumulation, Janelle Allison Shives

Loma Linda University Electronic Theses, Dissertations & Projects

Organisms living in the intertidal zone must adapt to environmental and physical stressors. One physical stressor that these organisms may face, and that may require specific behavioral and physiological responses, is burial by sediment. In this thesis I report the results of experiments in which I subjected the intertidal hermit crab, Pagurus samuelis, to burial and analyzed aspects of subsequent behavior and physiology. In the first set of experiments, hermit crabs were buried with the shell aperture facing either up or down, and at one of three depths (2, 4, or 6 cm). The factors hermit crab weight, shell …

Ricin B Chain-Insulin Fusion Protein Immunomodulation Of Type 1 Diabetes, James Edward Carter Iii

Loma Linda University Electronic Theses, Dissertations & Projects

Type 1 diabetes mellitus (T1D) is a debilitating chronic inflammatory disease of the insulin-producing pancreatic islet β-cells that results from a combination of genetic and environmental factors. Attempts to suppress Th1-mediated autoimmune diseases such as T1D by mucosal delivery of autoantigens for immunotolerization have yielded only partial success. Attainment of satisfactory levels of sustained immunological tolerance remains to be accomplished. To restore self-tolerance requires delivery of sufficient amounts of autoantigen to stimulate regulatory T helper cells that function to survey the gut and induce tolerance to consumed antigens such as food. Oral delivery of autoantigens has previously been shown to …

Calling On Science: Making “Alternatives” The New Gold Standard, Melvin E. Andersen

in Vitro Research Models Collection

All of life’s great journeys start with a goal in mind! The 2007 NAS report, Toxicity Testing in the 21st Century – A Vision and A Strategy, has proposed a clear goal. This report envisions a not-so-distant future where all routine toxicity testing for environmental agents will be conducted in human cells in vitro evaluating perturbations of cellular responses in a suite of toxicity pathway assays. Dose response modeling would utilize computational systems biology models of the circuitry underlying each toxicity pathway; in vitro to in vivo extrapolations would use pharmacokinetic models, ideally physiologically based pharmacokinetic models, to predict human …

Toxicity Testing In The 21st Century: A Vision And A Strategy, Daniel Krewski, Daniel Acosta Jr, Melvin Anderson, Henry Anderson, John C. Bailar Iii, Kim Boekelheide, Robert Brent, Gail Charnley, Vivian G. Cheung, Sidney Green Jr, Karl T. Kelsey, Nancy I. Kerkvliet, Abby A. Li, Lawrence Mccray, Otto Meyer, Reid D. Patterson, William Pennie, Robert A. Scala, Gina M. Solomon, Martin Stephens, James Yager, Lauren Zeise

Experimentation Collection

With the release of the landmark report Toxicity Testing in the 21st Century: A Vision and a Strategy, the U.S. National Academy of Sciences, in 2007, precipitated a major change in the way toxicity testing is conducted. It envisions increased efficiency in toxicity testing and decreased animal usage by transitioning from current expensive and lengthy in vivo testing with qualitative endpoints to in vitro toxicity pathway assays on human cells or cell lines using robotic high-throughput screening with mechanistic quantitative parameters. Risk assessment in the exposed human population would focus on avoiding significant perturbations in these toxicity pathways. Computational systems …

The Current Scientific And Legal Status Of Alternative Methods To The Ld50 Test For Botulinum Neurotoxin Potency Testing, Sarah Adler, Gerd Bicker, Hans Bigalke, Christopher Bishop, Jörg Blümel, Dirk Dressler, Joan Fitzgerald, Frank Gessler, Heide Heuschen, Birgit Kegel, Andreas Luch, Catherine Milne, Andrew Pickett, Heidemarie Ratsch, Irmela Ruhdel, Dorothea Sesardic, Martin Stephens, Gerhard Stiens, Peter D. Thornton, René Thürmer, Martin Vey, Horst Spielmann, Barbara Grune, Manfred Liebsch

Experimentation Collection

No abstract provided.

Bringing Toxicology Into The 21st Century: A Global Call To Action, Troy Seidle, Martin Stephens

Experimentation Collection

Conventional toxicological testing methods are often decades old, costly and low-throughput, with questionable relevance to the human condition. Several of these factors have contributed to a backlog of chemicals that have been inadequately assessed for toxicity. Some authorities have responded to this challenge by implementing large-scale testing programmes. Others have concluded that a paradigm shift in toxicology is warranted. One such call came in 2007 from the United States National Research Council (NRC), which articulated a vision of ‘‘21st century toxicology” based predominantly on non-animal techniques. Potential advantages of such an approach include the capacity to examine a far greater …

Mnte-2-Pyp And Radiation In A Prostate Cancer Model: Implications For Radiotherapy, Adeola Y. Makinde

Loma Linda University Electronic Theses, Dissertations & Projects

A major limitation of successful radiation therapy in cancer treatment is the increase in normal tissue damage as higher doses are used to achieve greater tumor destruction. Radiation dose optimization in cancer therapy requires achieving maximum tumor destruction with minimal damage to normal tissue Antioxidants have been shown to protect normal tissues against radiation damage, as radiation-induced tissue damage results predominantly from reactive oxygen species that directly damage cellular components. However, for effective use as normal tissue radioprotectants in radiotherapy, these antioxidants must not protect the tumors. Mn (III) tetrakis (N-ethylpyridinium-2-yl) porphyrin (MnTE-2-PyP) is a metalloporphyrin antioxidant that has been …

Role Of No In The Regulation Of Cortisol Synthesis In Long-Term Hypoxic Sheep Fetal Adrenal, Tshepo Rothi Monau

Loma Linda University Electronic Theses, Dissertations & Projects

Our laboratory has demonstrated that sheep fetuses adapt to long-term hypoxia (LTH) by maintaining normal level of basal plasma cortisol despite increased adrenocorticotropic hormone (ACTH). But the mechanisms involved are not fully understood. Studies have shown that nitric oxide (NO) inhibits synthesis of steroid hormones in a variety of tissues, and in different animal species. Studies also showed that hypoxia increases both expression and activity levels of the nitric oxide (NO) generating enzyme, nitric oxide synthase (NOS), in certain tissues. We have here investigated the expression level and localization of NOS isoforms in sheep fetal adrenals. We also investigated the …

Estimates For Worldwide Laboratory Animal Use In 2005, Katy Taylor, Nicky Gordon, Gill Langley, Wendy Higgins

Laboratory Experiments Collection

Animal experimentation continues to generate public and political concern worldwide. Relatively few countries collate and publish animal use statistics, yet this is a first and essential step toward public accountability and an informed debate, as well as being important for effective policy-making and regulation. The implementation of the Three Rs (replacement, reduction and refinement of animal experiments) should be expected to result in a decline in animal use, but without regular, accurate statistics, this cannot be monitored. Recent estimates of worldwide annual laboratory animal use are imprecise and unsubstantiated, ranging from 28–100 million. We collated data for 37 countries that …

Non-Animal Methodologies Within Biomedical Research And Toxicity Testing, Andrew Knight

Experimentation Collection

Laboratory animal models are limited by scientific constraints on human applicability, and increasing regulatory restrictions, driven by social concerns. Reliance on laboratory animals also incurs marked – and in some cases, prohibitive – logistical challenges, within high-throughput chemical testing programmes, such as those currently underway within Europe and the US. However, a range of non-animal methodologies is available within biomedical research and toxicity testing. These include: mechanisms to enhance the sharing and assessment of existing data prior to conducting further studies, and physicochemical evaluation and computerised modelling, including the use of structure-activity relationships and expert systems. Minimally-sentient animals from lower …

The Development Of New Concepts For Assessing Reproductive Toxicity Applicable To Large Scale Toxicological Programmes, S. Bremer, C. Pellizzer, S. Hoffmann, T. Seidle, T. Hartung

Experimentation Collection

Large scale toxicological testing programmes which are currently ongoing such as the new European chemical legislation REACH require the development of new integrated testing strategies rather than applying traditional testing schemes to thousands of chemicals. The current practice of requiring in vivo testing for every possible adverse effect endanger the success of these programmes due (i) to limited testing facilities and sufficient capacity of scientific/technical knowledge for reproductive toxicity; (ii) an unacceptable number of laboratory animals involved (iii) an intolerable number of chemicals classified as false positive.

A key aspect of the implementation of new testing strategies is the determination …

The Effect Of Radiation And Repeated Sub-Culturing On Tgf-Β1 Signaling In Frtl-5 Cells, Cheryl G. Burrell

Loma Linda University Electronic Theses, Dissertations & Projects

From our ongoing in vitro studies using the Fisher Rat Thyroid cell line-5 (FRTL-5) we recorded accelerated growth, reduced follicularization and reduction in thyroxin release that occurred as the cells were repeatedly sub-cultured. We also recorded that these changes occurred earlier and more rapidly following radiation exposure. We determined that TGF-β1 production increased under both conditions. We hypothesized that alteration in the TGF-β1 signaling pathway contributed to the changes observed in the cellular properties of FRTL-5 cells. Our objective was to examine some of the players in the TGF-β1 signaling pathway to determine whether radiation and/or repeated subculturing promoted changes …

Radiation-Induced Increases In Pkc Modulate Integrin Expression And Contribute To Fibrotic Changes, Pinal Rushikesh Pandya

Loma Linda University Electronic Theses, Dissertations & Projects

The sequences of events in fibrosis are similar to those in wound healing; however, the normal termination and resolution stages do not take place. The initial cellular response following ionizing radiation involves accumulation of the ECM (extracellular matrix) including collagen, fibronectin and the interaction of many growth factors (cytokines) with their receptors. There are a number of unanswered questions regarding many aspects of radiation-induced fibrosis, including the initial triggers and physical changes that initiate the process. We have confirmed that elevated pKC and other cellular changes following radiation are similar to those found at sites of inflammation. This information leads …

Effects Of Diabetes Mellitus On The Healing Of The Dental Pulp, Stuart Evan Garber

Loma Linda University Electronic Theses, Dissertations & Projects

Diabetes Mellitus (DM) has been implicated as a factor affecting healing. The purpose of this study was to use the healing of experimentally exposed pulps subsequent to pulp capping as a model to determine the effect of DM on healing.

Twenty-two Sprague-Dawley rats were divided into two groups of eleven animals each. In one group, DM was induced by injection of 70 mg/KG of streptozotocin. In the other group, the animals were injected with sterile saline. Under anesthesia with Ketamine and Xylazine, the pulps of the maxillary first molars of all rats were exposed using a 1/16 round bur under …

Histological Comparison Of White And Gray Mta In Repair Of Furcation Perforations, Miguel Elias Mego

Loma Linda University Electronic Theses, Dissertations & Projects

Mineral trioxide aggregate (MTA) has been shown to promote regeneration of the periodontal apparatus when used as a repair material in furcation perforations. Two variations of MTA (Gray and White) have been introduced to the dental market. The purpose of this study was to histologically compare the in vivo response to immediate furcation perforation repair using gray or white MTA in beagle dogs.

Under general anesthesia, non-surgical root canal therapy and furcal perforations were performed on sixteen mandibular premolars of eight 2-year old beagle dogs. The perforations were immediately repaired with either white (n=8) or gray (n=8) MTA. The animals …

Alternative Assay Techniques For Protein Kinase A, Justin Brink

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

The Future Of Teratology Research Is In Vitro, Jarrod Bailey, Andrew Knight, Jonathan Balcombe

Experimentation Collection

Birth defects induced by maternal exposure to exogenous agents during pregnancy are preventable, if the agents themselves can be identified and avoided. Billions of dollars and manhours have been dedicated to animal-based discovery and characterisation methods over decades. We show here, via a comprehensive systematic review and analysis of this data, that these methods constitute questionable science and pose a hazard to humans. Mean positive and negative predictivities barely exceed 50%; discordance among the species used is substantial; reliable extrapolation from animal data to humans is impossible, and virtually all known human teratogens have so far been identified in spite …

127 Million Non-Human Vertebrates Used Worldwide For Scientific Purposes In 2005, Andrew Knight

Experimentation Collection

No abstract provided.

Ld50 Testing Of Botulinum Toxin For Use As A Cosmetic, Martin L. Stephens, Michael Balls

Experimentation Collection

In 2003, the Fund for the Replacement of Animals in Medical Experiments (FRAME) revealed that the potency of botulinum toxin for use as a popular wrinkle treatment is assessed by using the LD50 Test. The endpoint in this mouse-based testing is death through suffocation. In 2004, The Humane Society of the United States (HSUS) sought to work with Allergan, the US-based manufacturer of Botox® Cosmetic, and the U.S. Food and Drug Administration (FDA), on ways to refine, reduce, and replace this LD50 testing. This article summarises The HSUS’s campaign in the United States and provides an update on FRAME’s continuing …

Enterotoxin B Subunit Lectins As Adjuvants For Improvement Of Mucosal Vaccine, Nak-Won Choi

Loma Linda University Electronic Theses, Dissertations & Projects

In comparison with whole organism vaccines, subunit vaccines may be safer for immunization but may lack sufficient immunogenicity to provide complete immunity to the pathogen. To resolve this problem, bacterial and plant enterotoxin B subunit adjuvants containing a variety of receptor-binding properties were used to enhance the immunogenicity of rotavirus subunit vaccines. Enterotoxin B subunit adjuvants were employed to enhance protection against virus infection. Pentameric cholera toxin B subunit (CTB), shiga toxin-1 B subunit (STB) and monomeric ricin toxin B subunit (RTB) molecules were genetically linked to a 90 amino acid peptide from the simian rotavirus (SA11) nonstructural protein NSP4 …

Ideology Masquerading As Science: The Case Of Endocrine Disrupter Screening Programmes, Troy Seidle

Experimentation Collection

The global move to develop novel testing methods and strategies to identify suspected endocrine disrupting chemicals offers a unique opportunity to move away from traditional animal testing paradigms in this new area of regulatory concern. Regrettably, the programmes under development, both in the USA and internationally through the OECD, have thus far failed to consider in vitro and other nonanimal test methods as more than “pre-screening” or “priority-setting” tools in a larger, animal-based testing strategy. Validation efforts to date have focused almost exclusively on the modification of existing animal tests to detect “endocrine effects”, with no demonstrable effort to promote …

Effect Of Anti-Tgfß1 And Pycnogenol® On Scar Formation In Rats, Pilseong Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Wound healing is a complex biologic process that involves chemotaxis and division of cells, neovascularization, synthesis of extracellular matrix proteins, and remodeling of the repaired tissues. Of equal importance is the restoration of normal tissue structure and function without scar formation. The aim of this study was to find out the clinical effects of anti-TGFß1 and Pycnogenol® on scarless wound healing on rat skin.

An acute incision wound model was used with 20 healthy rats. Four incisions were made on each rat's skin and 4 different variables were applied by local infiltration. The four variables were anti-TGFß1, Pycnogenol®, PBS, and …

Medical Training Using Simulation: Toward Fewer Animals And Safer Patients, Jonathan Balcombe

Experimentation Collection

This paper presents the current status of computer-based simulation in medicine. Recent technological advances have enabled this field to emerge from esoteric explorations in academic laboratories to commercially available simulators designed to train users to perform medical procedures from start to finish. Today, more than a dozen companies are producing virtual reality simulators and interactive manikins for training in endoscopy, laparoscopy, anaesthesia, trauma management, angiography, and needle insertion. For many of these procedures, thousands of animals are still being used in training. Yet simulation has many advantages that can transcend scientific, ethical, economic and logistical problems that arise when using …

Effects Of Various Hemostatic Agents On Bone, David Daryl Roland

Loma Linda University Electronic Theses, Dissertations & Projects

Previous studies have evaluated the effects of various hemostatic agents on radicular tissues following apical surgery. The purpose of this study was to examine the early osseous responses to seven hemostatic agents under identical conditions in rabbits. Sixteen adult male New Zealand white rabbits were used for this study. Following anesthesia, utilizing a midline submandibular incision, standardized bony defects were prepared on the lateral-superior regions of the mandible. Test materials were placed using standardized volumes and exposure times. Bone wax, Surgicel, Capset, alginate, Cut-Trol, Hemogin-L, and silver nitrate were compared to control sites irrigated with saline. Test materials or controls …

Identification Of Hard Tissue Using Dentin Sialoprotein (Dsp) As A Marker, Wallis E. Andeline

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to identify the early hard tissue formed in experimental pulp exposures capped with calcium hydroxide, mineral trioxide aggregate (MTA) or bone morphogenetic protein-7 (BMP-7) using dentin sialoprotein (DSP) as a marker. The pulps of eighty-five maxillary first, second and third molar teeth from twenty male rats were experimentally exposed. The exposed pulps were capped with calcium hydroxide followed by restoration with amalgam (n = 20), with MTA alone as a pulp capping agent and final restoration (n = 20) or with BMP-7 followed by restoration with MTA (n = 20). Ten teeth with Class …

Possibilities For Refinement And Reduction: Future Improvements Within Regulatory Testing, Martin L. Stephens, Kathleen Conlee, Gina Alvino, Andrew N. Rowan

Experimentation Collection

Approaches and challenges to refining and reducing animal use in regulatory testing are reviewed. Regulatory testing accounts for the majority of animals reported in the most painful and/or distressful categories in the United States and Canada. Refinements in testing, including the use of humane endpoints, are of increasing concern. Traditional approaches to reduction (e.g., improving experimental design) are being supplemented with complementary approaches, such as the use of tier testing to eliminate some chemicals prior to in vivo testing. Technological advances in telemetry and noninvasive techniques will help decrease either the demand for animals in testing or animal suffering. Further …

Effects Of A Serine 364 To Proline Mutation Of The Connexin43 Protein In Transgenic Mice, Chia-Ling Nhan-Chang

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]

Effects Of Liposome-Encapsulated Tnf-Alpha And Radiation Against Colon Cancer, Dong Won Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Previous studies have shown that tumor necrosis factor-α (TNF-α) can augment the antitumor effects of radiation, inhibiting tumor progression to a greater extent than either modality alone. However, nonspecific toxicities associated with TNF-α have limited its use as an adjuvant. This limitation is potentially resolved with the encapsulation of TNF-α in sterically stabilized, PEGylated liposomes (STEALTH®). Thus, the overall hypothesis of the research was that the combination of radiation with STEALTH® liposome encapsulated TNF-α (SL-TNF-α) will have greater efficacy and fewer dose-limiting side effects in the LS174T human colorectal tumor xenograft model compared to the combination of free TNF-α and …

The Effect Of Chronic Hypoxia On Cardiac Function In The Fetal Ovine Heart, Rodney David Rodrigo

Loma Linda University Electronic Theses, Dissertations & Projects

It has been shown that long-term high altitude hypoxia during pregnancy was associated with a decrease in cardiac contractility in fetal sheep. Given that hypoxia caused apoptotic cell death in fetal and neonatal rat cardiomyocytes, the present study tested the hypothesis that chronic hypoxia during pregnancy increases apoptosis in the fetal sheep heart. Pregnant (d 30) sheep were divided between normoxic control and chronically hypoxic (maintained at high altitude, 3,820 m, PaO₂: 60 Torr for 110 days) groups. Hearts were isolated from near-term (d 140) fetal sheep, and samples from all four chambers, right and left atria, and …