John N. Norton

Cell-Cell Interactions and the Regulation of Testis Function

Regulatory interactions have been shown to occur between all the testicular cell types considered. The paracrine factors mediating these interactions generally influence either cellular growth or differentiation. The regulation of cellular growth is essential in the developing testis and is required for the maintenance of spermatogenesis in the adult testis. The rapid rate of germinal cell proliferation and the continuous but slowed growth of the peritubular cells and Leydig cells requires the presence of specific growth factors in the adult. Therefore, cell-cell interactions have evolved that involve growth factors such as IGF, TGF-alpha, TGF-beta and NGF. Other growth factors such as FGF or less characterized components like the seminiferous growth factor (SGF) also may be involved in the paracrine regulation of testis cell growth. An alternate cellular parameter to cell growth to consider is the regulation of cellular function and differentiation. A number of endocrine agents and locally produced paracrine factors have been shown to control and maintain testis cell function and differentiation. Cell-cell interactions mediated by factors such as androgens, POMC peptides, and PModS are all primarily directed at the regulation of cellular differentiation. Therefore, the agents which mediate cell-cell interactions in the testis can generally be categorized into factors that regulate cell growth or those which influence cellular differentiation. The specific cell-cell interactions identified will likely be the first of a large number of cellular interactions yet to be investigated. Although a number of potentially important cell-cell interactions have been identified, future research will require the elucidation of the in vivo physiological significance of these interactions. The existence of different cell types and potential cell-cell interactions in a tissue implies that the actions of an endocrine agent on a tissue will not simply involve a single hormone and single cell. The endocrine regulation of testis function will have effects on cell-cell interactions and be affected by local cell-cell interactions. The ability of LH to influence Leydig cell androgen production promotes a cascade of interactions mediated through several cell types to maintain the process of spermatogenesis. FSH actions on Sertoli cells also promote cell-cell interactions that influence germinal cell development, peritubular myoid cell differentiation and Leydig cell function. Therefore, elucidation of the endocrine regulation of testis function requires an understanding of the local cell-cell interactions in the testis.

Ocular biocompatibility testing of intraocular lenses: a 1 year study in pseudophakic rabbit eyes.

PURPOSE To evaluate the appropriate duration for conducting ocular biocompatibility studies with an intraocular lens (IOL) in the pseudophakic rabbit model. SETTING Alcon Laboratories, Inc., Fort Worth, Texas, USA. METHODS A single-piece biconvex poly(methyl methacrylate) (PMMA) IOL was implanted in the capsular bag of 18 eyes of New Zealand white rabbits; 8 eyes received sham surgeries. Rabbits were monitored clinically and then sacrificed 6 or 12 months after surgery for histopathological examination of ocular tissues. RESULTS Biomicroscopic examination revealed mild ocular changes in all surgical eyes during the first 3 months postoperatively. After that, there was a high incidence of posterior synechias, flare, and posterior capsule opacification (PCO) in eyes with PMMA IOLs. Posterior synechias and flare scores remained mild to moderate throughout the study, whereas PCO severity increased over time. Similar findings were observed in sham eyes. In addition, several eyes with PMMA IOLs developed IOL dislocation, hyphema, iris bombe, and a fibrous membrane covering the IOL. No discernible differences in biomicroscopic scores were observed in eyes at 6 or 12 months. Intraocular pressures and morphology of the corneal endothelium were normal in both groups. Results from histopathological analysis of the ocular tissues were consistent with observations from the biomicroscopic examinations. CONCLUSION The results suggest that IOL implantation studies in the pseudophakic rabbit eye should be conducted for 3 or fewer months. Regulatory guidelines requiring longer ocular implantation studies should be revised to reflect the inherently rapid and extensive ocular response in the rabbit model.

The cost of self-imposed regulatory burden in animal research

U.S. federal regulations and standards governing the care and use of research animals enacted in the mid‐ to late 1980s, while having positive effects on the welfare and quality of the animals, have resulted in dramatic increases in overall research costs. In addition to the expenses of housing and caring for animals according to the standards, establishing the requisite internal compliance bureaucracies has markedly driven up costs, in both institutional monetary expenditures and lost research effort. However, many institutions are increasing these costs even further through additional self‐imposed regulatory burden, typically characterized by overly complex compliance organizations and unnecessary policies and procedures. We discuss the sources of this self‐imposed burden and recommend strategies for avoiding it while preserving an appropriate focus on animal well‐being and research success.—Thulin, J. D., Bradfield, J. F., Bergdall, V. K., Conour, L. A., Grady, A. W., Hickman, D. L., Norton, J. N., Wallace, J. M. The cost of self‐imposed regulatory burden in animal research. FASEB J. 28, 3297–3300 (2014). www.fasebj.org

In vitro oral mucosa irritation testing with human cell cultures.

Cell cultures are a potentially useful model to predict in vivo oral mucosa irritation. To this end, oral mucosa organ equivalent cultures (OMOEC) and skin equivalent cultures (SEC), both derived from human tissue, were evaluated for their responsiveness to test dentifrices with graded degrees of irritation potential. OMOEC and SEC were treated with test dentifrices and responses were evaluated by histopathology, cell viability (MTT incorporation), and cytotoxicity [release of aspartate aminotransferase (AST)]. Cell viability in OMOEC and SEC was reduced in a dose- and time-dependent manner in response to the test dentifrices. Correspondingly, AST release was increased in a dose- and time-dependent manner in response to the test dentifrices. These results demonstrate that OMOEC and SEC systems respond linearly to graded degrees of irritation potential as represented by generic dentifrices. Such results in an in vitro model of oral mucosa irritation allow direct comparison of in vitro responses with those obtained in an in vivo model, thus providing the groundwork for a tiered approach to assessment of irritation potential of oral care products.

Diseases and Veterinary Care

Chinchillas have historically been raised for fur production and are docile pets. In the biomedical area, their use as a research model for the auditory system is well documented. Many of the veterinary care issues, whether from disease or trauma, are derived from either environmental or husbandry perturbations. Therefore in the modern vivarial setting, many of the conditions described in this chapter are non-existent or of a minimal impact on the health status of the chinchilla. However for completeness, a summary of the literature covering infectious diseases, metabolic and nutritional diseases, traumatic lesions, iatrogenic/management-related disorders, neoplastic diseases, and other miscellaneous conditions of chinchillas are presented. This review provides information on the etiology, clinical manifestations, pathology, diagnosis, prevention, and therapy of conditions affecting the health of chinchillas. Understanding of these conditions that may affect the health of chinchillas is important whether animals are housed in a controlled or less stringent environment.

Assessing the satisfaction and burden within an academic animal care and use program

Although animal research requires adherence to various regulations and standards, the manner in which compliance is maintained and the degree of additional constraints varies between institutions. Regulatory burden, particularly if institutionally imposed, has become a concern for institutions as increased regulatory expectations result in decreased resources available for research efforts. Faculty, research staff, and support staff engaged in animal research were surveyed to determine what institutional animal care and use committee (IACUC) processes were considered burdensome, the perceived value of some suggested modifications, and satisfaction with the IACUC administrative office and the animal resource unit. Although the results revealed overwhelming satisfaction with the IACUC administrative office and the animal resource unit, several IACUC processes were deemed burdensome, and therefore there would be value in modifying IACUC processes. When comparing the value of modifying IACUC processes, different groups within the animal care and use program (ACUP) tended to have different responses on many of the topics. This survey identified several perceived burdensome IACUC processes that would likely benefit individuals if modified. In today’s environment of shrinking budgets for biomedical research, minimizing regulatory burden—particularly unnecessary, self‐imposed burden—in the ACUP is particularly important to ensure that costs, time, and effort are appropriate to achieve animal welfare and quality of research endeavors.—Norton, J. N., Reynolds, R. P., Chan, C., Valdivia, R. H., Staats, H. F. Assessing the satisfaction and burden within an academic animal care and use program. FASEB J. 31, 3913–3921 (2017). www.fasebj.org—Norton, John N., Reynolds, Randall P., Chan, Cliburn, Valdivia, Raphael H., Staats, Herman F. Assessing the satisfaction and burden within an academic animal care and use program. FASEB J. 31, 3913–3921 (2017)

EVALUATION OF TWO RABBIT OCULAR IMPLANTATION MODELS USING POLYMETHYLMETHACRYLATE INTRAOCULAR LENSES

Polymethylmethacrylate (PMMA) is the standard intraocular lens (IOL) optic material based upon its long history of clinical use, stability and biocompatibility. Regulatory guidelines require IOLs that utilize novel lens material to be evaluated for biocompatibility in a long term (1 year) ocular implant study using an appropriate species and a reference IOL, e.g., PMMA. The purpose of this study was to evaluate the rabbit as a potential model for conducting long-term ocular implant studies that satisfy regulatory biocompatibility guidelines. In this study, lensectomy by phacoemulsification with implantation of PMMA IOLs in the capsular bag was performed on one group of rabbits, while a second group received only implantation of PMMA wafers (3 x 5 x 0.4mm) in the anterior chamber without lensectomy. Animals received ocular examinations at selected intervals during the study, e.g., slit-lamp biomicroscopy. Except for the expected postoperative inflammation, no signs of inflammation were observed in either rabbit model for up to approximately 3 months following implantation of the PMMA IOLs. However, after about 3 postoperative months rabbits with the PMMA IOLs in the capsular bag developed posterior synechiae, posterior capsular opacification (pearls and fibrosis), uveitis, and secondary cataracts. In some rabbits extrusion/displacement of the IOL haptics caused mechanical trauma to the iris with subsequent hyphema. In contrast, the rabbits that were implanted with the PMMA wafers in the anterior chamber did not display any signs of inflammation during a one year study period. Histopathology confirmed the presence of the ocular inflammation which was observed in the rabbits with the IOLs implanted in the capsular bag. These results demonstrate that studies using the rabbit to evaluate IOLs following lensectomy and capsular bag implantation should be limited to a shorter study duration of 6 months or less. In contrast, a longer study duration of up to one-year may be conducted in rabbits following implantation of IOL wafers into the anterior chamber. Fur-thermore, these studies demonstrate that the site of implantation and duration of study can influence results obtained in an ocular biocompatibility study.

Applied Biosafety’s Special Issue on Animal Safety

There are safety issues associated with animals used in research. Four main professional groups are directly affected by the human-animal interaction in the research setting: scientists (from student to principal investigator), veterinarians (veterinarian and veterinary technician), ancillary personnel (facilities/maintenance, janitorial staff, Institutional Animal Care and Use Committee [IACUC] inspectors), and house staff (research staff and animal care takers). This special issue of Applied Biosafety about safety issues associated with handling laboratory animals focuses on addressing salient risks found in this setting. Selected subject matter experts discuss topics on institutional oversight, biosafety, use of chemicals, physical hazards, laboratory-acquired infections, use of genetically modified animals, and use of nanomaterials. Melissa Dyson et al discuss the importance of institutional oversight associated with laboratory animals, emphasizing the interactions of the IACUC with other institutional committees and its responsibility to ensure animal welfare. Scott Alderman et al discuss biological safety issues specifically related to handling laboratory animals. Vanessa Lee et al present a comprehensive roadmap to hazard analyses when using chemical substances in animals. Karen Byers discusses laboratory-acquired infections from the laboratory animal perspective. Closing this special issue, Howard and Murashov present unique guidance for use of nanomaterials in laboratory animals. This issue is complementary to one in the ILAR Journal that is currently in production. In observance of National Biosafety Month, these special issues bring attention to the complexity, breadth, and scope of safety issues encountered by professionals handling laboratory animals and biosafety professionals conducting risk assessments and accident investigations or providing training to personnel. We hope the reader finds the topics addressed here and in the ILAR Journal relevant in their daily decision-making process. Two professional and accreditation associations have been brought together to assemble these special issues, the AAALAC International and ABSA International. AAALAC promotes the responsible use of laboratory animals, and in this special issue it provides a global perspective on current occupation health and safety gaps found in programs across animal research programs. ABSA International promotes biological safety in the laboratory setting and here provides trends on current issues associated with biosafety such as the use of nanomaterials in laboratory animals. The mission of these two associations intersects at the point of handling the laboratory animal. Emerging technologies and pathogens create challenges for contemporary research programs, requiring that all those involved in the use of laboratory animals understand and mitigate potential risks. The authors would like to recognize Paul Tranchell, Chair of ABSA International’s Emerging Infectious Diseases Consortium, and Dr. James Swearengen, Global Director of AAALAC, for supporting the initiative of bringing AAALAC and ABSA International together through their written media to devote attention to animal safety.

Vibration in mice: A review of comparative effects and use in translational research

Sound pressure waves surround individuals in everyday life and are perceived by animals and humans primarily through sound or vibration. When sound pressure waves traverse through a solid medium, vibration will result. Vibration has long been considered an unwanted variable in animal research and may confound scientific endeavors using animals. Understanding the characteristics of vibration is required to determine whether effects in animals are likely to be therapeutic or result in adverse biological effects. The eighth edition of the “Guide for the Care and Use of Laboratory Animals” highlights the importance of considering vibration and its effects on animals in the research setting, but knowledge of the level of vibration for eliciting these effects was unknown. The literature provides information regarding therapeutic use of vibration in humans, but the range of conditions to be of therapeutic benefit is varied and without clarity. Understanding the characteristics of vibration (eg, frequency and magnitude) necessary to cause various effects will ultimately assist in the evaluation of this environmental factor and its role on a number of potential therapeutic regimens for use in humans. This paper will review the principles of vibration, sources within a research setting, comparative physiological effects in various species, and the relative potential use of vibration in the mouse as a translational research model.

The Planning, Design and Construction Process

Publisher Summary This chapter describes the design process from conceptual design through all phases of engineering and construction of new facilities. The chapter also describes various design issues and potential pitfalls. The major activities in the design of an animal facility can be summarized in eight steps, including, programming and planning/master planning, schematic design, design development, construction documents preparation, bidding and construction contract award, construction phase, commissioning, and validation. Planning for new or expanded facilities usually results from programmatic requirements. Forces impacting these requirements may be growth of existing programs and research staff, changes or additions to programs, etc. Schematic design begins after approval of a facility program and conceptual master plan. It is during this phase that the floor plans and elevations are worked out. Important operational decisions need to be made during the design development phase. During construction-documents-preparation phase, final drawings and specifications are prepared by design team. During construction phase, milestones are identified at the end of each design phase, where formal design presentations and reviews are conducted, and client representatives are given the opportunity to comment on the design and engineering plans prior to start of construction. A risk assessment is conducted to evaluate potential hazards to the security of a building as well as daily operations.