Research Methods in Life Sciences Commons^™

Arkansas Animal Science Department Report 2006, Zelpha B. Johnson, D. Wayne Kellogg

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Report Of The Working Group On Animal Distress In The Laboratory, Marilyn Brown, Larry Carbone, Kathleen Conlee, Marian Dawkins, Ian J. Duncan, David Fraser, Gilly Griffin, Victoria A. Hampshire, Lesley A. Lambert, Joy A. Mench, David Morton, Jon Richmond, Bernard E. Rollin, Andrew N. Rowan, Martin L. Stephens, Hanno Würbel

Laboratory Experiments Collection

Finding ways to minimize pain and distress in research animals is a continuing goal in the laboratory animal research field. Pain and distress, however, are not synonymous, and often measures that alleviate one do not affect the other. Here, the authors provide a summary of a meeting held in February 2004 that focused on distress in laboratory animals. They discuss the difficulties associated with defining ‘distress,’ propose methods to aid in recognizing and alleviating distressful conditions, and provide recommendations for animal research conduct and oversight that would minimize distress experienced by laboratory animals.

In Vitro Antimicrobial Efficacy Of Calcium Hydroxides In Root Dentin, Josef W. Lubisich

Loma Linda University Electronic Theses, Dissertations & Projects

Enterococcus faecalis is the most commonly isolated bacteria in failed root canal treatment. Endodontic intracanal medicaments are commonly tested using standardized bovine cylinders infected with bacteria. The literature is not clear on whether calcium hydroxides are able to remove E. faecalis from the dentinal tubules. One reason for this is that there are several varying forms of calcium hydroxide commonly used. The purpose of the present experiment was to determine whether four commonly used calcium hydroxide products were able to reduce E. faecalis from four incremental samples of dentin and to determine if there was a statistically significant difference between …

Sheep Updates 2006 - Part 3, Karen Venning, Andrew Thompson, Mike Hyder, Sue-Ellen Shaw, Kelly Hill, Ron Mctaggart, Gus Rose, Carolyn Kabore, Mandy Curnow, P. R. Kenyon, S. T. Morris, D. M. West, N. R. Perkins, G. L. Pinchbeck, Ralph Behrendt

Sheep Updates

This session covers six papers from different authors:

GRAZING

1. Making better use of clover, Karen Venning and Andrew Thompson, Department of Primary Industries, Victoria

2. Grazing systems demonstration to optimise pasture utilisation and stocking rate, Mike Hyder, Sue-Ellen Shaw, Kelly Hill and Ron McTaggart, Department of Agriculture and Food Western Australia.

3. Know your audience to increase their rate of practice change - Lifetime Wool as an example, Gus Rose, Department of Agriculture and Food Western Australia, Carolyn Kabore, Kazresearch

REPRODUCTION

4. Lifetime Wool - Ewe Management Guidlines, Mandy Curnow, Department of Agriculture and Food Western Australia

5. …

The Effect Of Calcium Hydroxide Pastes On Root Dentin Fracture Resistance, Kurt W. Sturz

Loma Linda University Electronic Theses, Dissertations & Projects

Calcium hydroxide is a common intracanal medicament used in the treatment of immature teeth that have been subjected to trauma or decay prior to root canal therapy. The effect of calcium hydroxide on immature root dentin is important. One area of concern is the effect that calcium hydroxide has on the fracture resistance of an immature tooth. It is the aim of this study to compare the effect of four different commercially available calcium hydroxide pastes on the fracture resistance of bovine teeth. Seventy-five freshly extracted, intact bovine incisors were prepared according to a modified Haapasalo and Orstavik technique. Each …

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 …

Animal Carcinogenicity Studies: Implications For The Reach System, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Experimentation Collection

The 2001 European Commission proposal for the Registration, Evaluation and Authorisation of Chemicals (REACH) aims to improve public and environmental health by assessing the toxicity of, and restricting exposure to, potentially toxic chemicals. The greatest benefits are expected to accrue from decreased cancer incidences. Hence the accurate identification of chemical carcinogens must be a top priority for the REACH system. Due to a paucity of human clinical data, the identification of potential human carcinogens has conventionally relied on animal tests. However, our survey of the US Environmental Protection Agency’s (EPA’s) toxic chemicals database revealed that, for a majority of the …

Animal Carcinogenicity Studies: 1. Poor Human Predictivity, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Experimentation Collection

The regulation of human exposure to potentially carcinogenic chemicals constitutes society’s most important use of animal carcinogenicity data. Environmental contaminants of greatest concern within the USA are listed in the Environmental Protection Agency’s (EPA’s) Integrated Risk Information System (IRIS) chemicals database. However, of the 160 IRIS chemicals lacking even limited human exposure data but possessing animal data that had received a human carcinogenicity assessment by 1 January 2004, we found that in most cases (58.1%; 93/160), the EPA considered animal carcinogenicity data inadequate to support a classification of probable human carcinogen or non-carcinogen. For the 128 chemicals with human or …

Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Experimentation Collection

Conventional animal carcinogenicity tests take around three years to design, conduct and interpret. Consequently, only a tiny fraction of the thousands of industrial chemicals currently in use have been tested for carcinogenicity. Despite the costs of hundreds of millions of dollars and millions of skilled personnel hours, as well as millions of animal lives, several investigations have revealed that animal carcinogenicity data lack human specificity (i.e. the ability to identify human non-carcinogens), which severely limits the human predictivity of the bioassay. This is due to the scientific inadequacies of many carcinogenicity bioassays, and numerous serious biological obstacles, which render profoundly …

Animal Carcinogenicity Studies: 2. Obstacles To Extrapolation Of Data To Humans, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Experimentation Collection

Due to limited human exposure data, risk classification and the consequent regulation of exposure to potential carcinogens has conventionally relied mainly upon animal tests. However, several investigations have revealed animal carcinogenicity data to be lacking in human predictivity. To investigate the reasons for this, we surveyed 160 chemicals possessing animal but not human exposure data within the US Environmental Protection Agency chemicals database, but which had received human carcinogenicity assessments by 1 January 2004. We discovered the use of a wide variety of species, with rodents predominating, and of a wide variety of routes of administration, and that there were …

The Class B Dealer: Down And Out?, Bernard Unti

Laboratory Experiments Collection

The supply of dogs and cats to laboratories by Class B animal dealers has been a contentious matter for decades. The subject engenders heated debate whenever it surfaces, most recently in September 2005 when Senator Daniel Akaka (D-HI) proposed an amendment to the FY 2006 agriculture funding bill to withhold federal monies to research institutions that purchase animals from Class B dealers.

Cancerous Contradictions: The Mis-Regulation Of Human Carcinogens Based On Animal Data, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Experimentation Collection

The regulation of human exposures to potential carcinogens constitutes society’s most important use of animal carcinogenicity data. However, for environmental contaminants of greatest U.S. concern, we found that in most cases (58.1%; 93/160) the U.S. Environmental Protection Agency (EPA) considered the animal data inadequate to support a classification of probable human carcinogen or noncarcinogen.

The World Health Organisation’s International Agency for Research on Cancer (IARC) is a leading international authority on carcinogenicity assessments. For chemicals lacking human exposure data (the great majority), IARC classifications of identical chemicals were significantly more conservative than EPA classifications (p

Stromal Haze, Myofibroblasts, And Surface Irregularity After Prk, Marcelo V. Netto, Rajiv R. Mohan, Sunilima Sinha, Ajay Sharma, William Dupps, Steven E. Wilson

Pharmacy Faculty Articles and Research

The aim of this study was to investigate the relationship between the level of stromal surface irregularity after photorefractive keratectomy (PRK) and myofibroblast generation along with the development of corneal haze.

Variable levels of stromal surface irregularity were generated in rabbit corneas by positioning a fine mesh screen in the path of excimer laser during ablation for a variable percentage of the terminal pulses of the treatment for myopia that does not otherwise generate significant opacity. Ninety-six rabbits were divided into eight groups[.]

Slit lamp analysis and haze grading were performed in all groups. Rabbits were sacrificed at 4 hr …

Effect Of Prophylactic And Therapeutic Mitomycin C On Corneal Apoptosis, Cellular Proliferation, Haze, And Long-Term Keratocyte Density In Rabbits, Marcelo V. Netto, Rajiv R. Mohan, Sunilima Sinha, Ajay Sharma, Pankaj C. Gupta, Steven E. Wilson

Pharmacy Faculty Articles and Research

PURPOSE—To determine the mechanism through which topical mitomycin C prevents and treats corneal haze after photorefractive keratectomy (PRK) and to examine the effects of dosage and duration of exposure.

METHODS—In 224 New Zealand rabbits, −9.0 diopter PRK with mitomycin C or balanced salt solution was performed. Haze level was graded at the slit-lamp. Rabbits were sacrificed at 4 hours, 24 hours, 4 weeks, or 6 months after surgery and immunohistochemistry was performed with TUNEL assay, Ki67 and α-SMA.

RESULTS—TUNEL-positive apoptotic cells marginally increased in all mitomycin C groups whereas Ki67-positive mitotic cells decreased significantly following mitomycin C application. A greater …