Sex-related differences in the progressive retinal degeneration of the rd10 mouse.

The retinal degeneration 10 (rd10) mouse is a model of autosomal recessive retinitis pigmentosa (RP), a disease that causes blindness through the progressive loss of photoreceptors. This study shows evidence of sex-related differences in RP onset and progression in rd10 retinas. The disease onset was considerably earlier in the female rd10 mice than in the male rd10 mice, as evidenced by a loss of PDE6ß proteins and rod-dominated electroretinogram (ERG) responses at an early age. Single photopic flash and flicker ERG responses and immunolabeling of opsin molecules were analyzed in both genders to assess the sex differences in the degeneration of cones in the RP retinas. The averaged amplitudes of cone-mediated ERG responses obtained from the females were significantly smaller than the amplitudes of the responses from the age-matched males in the late stages of the RP, suggesting that cones might degenerate faster in the female retinas as the disease progressed. The rapid degeneration of cones caused a more substantial decrease in the ERG responses derived from the On-pathway than the Off-pathway in the females. In addition, the male rd10 mice had heavier body weights than their female counterparts aged between postnatal (P)18 and P50 days. In summary, female rd10 mice were more susceptible to retinal degeneration, suggesting that the female sex might be a risk factor for RP. The results have important implications for future studies exploring potential sex-related differences in RP development and progression in the clinic.

Ensuring due process in the IACUC and animal welfare setting: considerations in developing noncompliance policies and procedures for institutional animal care and use committees and institutional officials.

Every institution that is involved in research with animals is expected to have in place policies and procedures for the management of allegations of noncompliance with the Animal Welfare Act and the U.S. Public Health Service Policy on the Humane Care and Use of Laboratory Animals. We present here a model set of recommendations for institutional animal care and use committees and institutional officials to ensure appropriate consideration of allegations of noncompliance with federal Animal Welfare Act regulations that carry a significant risk or specific threat to animal welfare. This guidance has 3 overarching aims: 1) protecting the welfare of research animals; 2) according fair treatment and due process to an individual accused of noncompliance; and 3) ensuring compliance with federal regulations. Through this guidance, the present work seeks to advance the cause of scientific integrity, animal welfare, and the public trust while recognizing and supporting the critical importance of animal research for the betterment of the health of both humans and animals.-Hansen, B. C., Gografe, S., Pritt, S., Jen, K.-L. C., McWhirter, C. A., Barman, S. M., Comuzzie, A., Greene, M., McNulty, J. A., Michele, D. E., Moaddab, N., Nelson, R. J., Norris, K., Uray, K. D., Banks, R., Westlund, K. N., Yates, B. J., Silverman, J., Hansen, K. D., Redman, B. Ensuring due process in the IACUC and animal welfare setting: considerations in developing noncompliance policies and procedures for institutional animal care and use committees and institutional officials.

Novel pathologic findings associated with urinary retention in a mouse model of mucopolysaccharidosis type IIIB.

Mucopolysaccharidosis type IIIB (MPS IIIB; Sanfilippo syndrome type B) is a metabolic disorder with devastating clinical characteristics starting in early childhood and leading to premature death. A knockout mouse strain was developed that models this disease. Mice of the strain B6.129S6- Naglu(tm1Efn)/J are invaluable for investigating pathogenesis and possible treatment modalities. However, the mouse strain also exhibits some objectionable phenotypic features. One such feature, urinary retention, not only is atypical of human MPS IIIB but often leads to early termination of experiments due to animal welfare concerns. The aim of this study was to investigate abnormalities associated with the urinary retention. Necropsies were performed on 9-mo-old mice; urinalysis, hematology and blood chemistry parameters were evaluated, and urogenital specimens were microscopically examined. Histopathologic examinations of urinary tract specimens proved illuminating regarding pathology in the urinary tract. A large mononuclear cell infiltrate was discovered in mutant mice of both sexes, more pronounced in females compared with male mice. The infiltrate comprises of large rounded or polygonal cells with generous variably vacuolated, granular eosinophilic cytoplasm and small round vesicular nuclei. These cells were present throughout and expand the interstitium of the lower urinary tract. Either this results in extrinsic compression of the lumen of the urethra, eventually leading to obstructive uropathy, bladder hyperdistension, and urinary retention or possibly interferes with the neurogenic component of micturition needs to be further investigated. The novel finding of an unexpected mononuclear cell infiltrate in the urinary tract in the knockout mice B6.129S6- Naglu(tm1Efn)/J is reported.

Maternal transplantation of human umbilical cord blood cells provides prenatal therapy in Sanfilippo type B mouse model.

Numerous data support passage of maternal cells into the fetus during pregnancy in both human and animal models. However, functional benefits of maternal microchimerism in utero are unknown. The current study attempted to take advantage of this route for prenatal delivery of alpha-N-acetylglucosaminidase (Naglu) enzyme into the enzyme-deficient mouse model of Sanfilippo syndrome type B (MPS III B). Enzymatically sufficient mononuclear cells from human umbilical cord blood (MNC hUCB) were intravenously administered into heterozygote females modeling MPS III B on the 5th day of pregnancy during blastocyst implantation. The major findings were 1) administered MNC hUCB cells transmigrated and diffused into the embryos (E12.5); 2) some transmigrated cells expressed CD34 and CD117 antigens; 3) transmigrated cells were found in both the maternal and embryonic parts of placentas; 4) transmigrated cells corrected Naglu enzyme activity in all embryos; 5) administered MNC hUCB cells were extensively distributed in the organs and the blood of heterozygote mothers at one week after transplantation. Results indicate that prenatal delivery of Naglu enzyme by MNC hUCB cell administration into mothers of enzyme-deficient embryos is possible and may present a significant opportunity for new biotechnologies to treat many inherited disorders.

Deep subconjunctival injection of gentamicin for the treatment of bacterial conjunctivitis in macaques (Macaca mulatta and Macaca fascicularis).

Infectious conjunctivitis occurs in a number of domestic and laboratory animal species and is usually treated topically with eye drops or eye ointments, which must be administered several times a day and sometimes for a prolonged period of time. In aggressive nonhuman primates or other large laboratory animal species, this may require the use of anesthesia or physical restraint before each treatment, which can be stressful to the animals and demanding for personnel. The authors describe a technique for administering deep subconjunctival injections of an antibiotic to laboratory macaques for the treatment of conjunctivitis. Three cases of recurrent conjunctivitis in macaques that responded poorly to other treatment approaches were effectively treated using this technique. This approach is recommended for the treatment of conjunctivitis in macaques and other large animal species.

Mouse model of Sanfilippo syndrome type B: relation of phenotypic features to background strain.

Sanfilippo syndrome type B or mucopolysaccharidosis type III B (MPS IIIB) is a lysosomal storage disorder that is inherited in autosomal recessive manner. It is characterized by systemic heparan sulfate accumulation in lysosomes due to deficiency of the enzyme alpha-N-acetylglucosaminidase (Naglu). Devastating clinical abnormalities with severe central nervous system involvement and somatic disease lead to premature death. A mouse model of Sanfilippo syndrome type B was created by targeted disruption of the gene encoding Naglu, providing a powerful tool for understanding pathogenesis and developing novel therapeutic strategies. However, the JAX GEMM Strain B6.129S6-Naglutm1Efn mouse, although showing biochemical similarities to humans with Sanfilippo syndrome, exhibits aging and behavioral differences. We observed idiosyncrasies, such as skeletal dysmorphism, hydrocephalus, ocular abnormalities, organomegaly, growth retardation, and anomalies of the integument, in our breeding colony of Naglu mutant mice and determined that several of them were at least partially related to the background strain C57BL/6. These background strain abnormalities, therefore, potentially mimic or overlap signs of the induced syndrome in our mice. Our observations may prove useful in studies of Naglu mutant mice. The necessity for distinguishing background anomalies from signs of the modeled disease is apparent.

A unique application to the IACUC for studies of wild animals in or from natural settings.

The format of an application to the Institutional Animal Care and Use Committee (IACUC) frequently is designed to obtain detailed information from medical faculty proposing studies involving a precisely determined number of a few well-characterized species in a controlled laboratory setting. Unfortunately, these application formats typically are less than ideal for marine and field biologists attempting to propose studies of large populations of diverse organisms in a comparatively uncontrolled environment and somewhat unpredictable setting. Traditional IACUC applications rarely address topics of field capture, restraint, marking, animal care in the field, and release of animals back into the environment. Yet the IACUC at institutions that receive federal funds for research involving vertebrate animals is obligated by federal policy to ensure that field studies adhere to the same basic tenets of humane animal care, use, and treatment that guide traditional laboratory animal studies. The University of South Florida IACUC established written policies and developed a specialized application to the IACUC that specifically requests from biologists the relevant details of their proposed field research involving vertebrate animals. These new policies and application format have improved understanding and communication of field biological studies and have helped ensure accountability of vertebrate animal use in the field.

Successful management of long-term general anesthesia in rabbits used as an animal model of human disease.

The rabbit represents a popular animal model for basic science research, but projects requiring anesthesia and endotracheal intubation represent a technical challenge because of the difficulty in accessing the animal's airway and sensitivity to common anesthetic agents. We hypothesized that transoral intubation under direct visualization with guidewire assistance would improve airway access success and reduce perioperative mortality in the rabbit. Of the 39 New Zealand White rabbits that had passive inhalation anesthesia and were intubated using wire-guided assistance under direct laryngeal visualization, 33 were intubated using a flexible wire after the rigid guide had resulted in airway injury in three of the first six rabbits. Animals were then maintained under general anesthesia during a 4- to 5-h procedure. At the completion of the procedure, animals were recovered from anesthesia and extubated. All 39 animals were successfully intubated, mostly on the first attempt. There were two animal deaths, both in the first six animals; one death was a direct result of laryngeal injury from the rigid wire guide initially used. One additional animal in the first six had pulmonary difficulty after an airway injury but recovered and was successfully used in the experiment. Two animals developed gastric distention during anesthesia, which was alleviated with placement of an orogastric tube without adverse sequelae. No animals developed problems with oxygenation during the experiment, but over half (52.8%) had end-tidal CO2 (ETCO2) above 45 mmHg at least once during the surgery, and 13 rabbits were above this level for longer than 1 h. An average of 18 min elapsed between withdrawal of anesthesia and the time when spontaneous respirations and chewing movements returned. Animals then could be safely extubated. There was no correlation between high perioperative ETCO2 and time to recovery from anesthesia (P = 0.18, r = 0.23).

USE OF FUSED CIRCULATIONS TO INVESTIGATE THE ROLE OF APOLIPOPROTEIN E AS AMYLOID CATALYST AND PERIPHERAL SINK IN ALZHEIMER'S DISEASE.

Apolipoprotein E (apoE) synthesized in liver and brain plays a key role in both cholesterol transport and Alzheimer's disease (AD): apoE-knockout mice develop hypercholesterolemia and atherosclerosis and cannot support AD amyloid deposition. The ApoE4 allele is the strongest genetic risk factor for late-onset AD, and apoE4 protein preferentially catalyzes amyloid-beta (Aß) peptide fibrillization in vitro and amyloid plaque deposition in vivo. Circulating apoE may also have the potential to draw Aß from the brain and reduce amyloid deposition. We used parabiosis to determine how circulating apoE impacts brain amyloid deposition and blood cholesterol levels in transgenic mice carrying AD-promoting APP and PS1 human transgenes-either with or without the endogenous mouse apoE gene. ApoE transferred through the joined circulations from WT to parabiosed APP+/+,PS1+/-,apoE-KO mice prevented hypercholesterolemia and reduced already low brain amyloid deposition. The findings indicate that apoE synthesis in the brain itself is necessary for amyloid accumulation. Furthermore, plasma apoE can both normalize cholesterol levels in apoE-KO mice and act as a peripheral sink to induce net efflux of Aß peptide from the brain. The therapeutic implication is that inhibiting Alzheimer's disease neuropathology may be accomplished by either reducing apoE in the brain or increasing apoE in the blood.