IntroductionLiver-directed gene transfer using adeno-associated virus (AAV) vectors has the potential to serve as therapy for several inherited hematologic diseases. One such disease is the bleeding disorder hemophilia B, caused by a deficiency in coagulation factor IX (FIX). Currently, there are 2 clinical trials for hemophilia B that use liver-directed AAV-mediated gene transfer of the F9 gene (www. clinicaltrials.gov; identifiers NCT00515710 and NCT00979238). One of these trials reported transient efficacious circulating FIX levels (ϳ 10%) with the use of the vector AAV2-hFIX16. 1 Although AAV vectors are predominantly nonintegrating, with most of the transgene expression from stable episomes, 2 it has been shown through direct sequencing that integration can occur. 3,4 When integration takes place, there is a preference for integrating in regions where DNA breaks occur. These can be regions of endonuclease cleavage, 5 active transcription, 6-8 cytosine-phosphateguanosine (CpG) islands, 7,8 and palindromes. 9 All of these studies describing AAV vector genome integration identified vector integration sites through plasmid rescue of vectors containing bacterial origins of replication (ori). 4 Amplification of these plasmids in bacterial culture allows for sequencing of the integration junction between vector and host genome. Because of the bacterial selection involved in this method, bias may occur against recovering integrants whose size or sequence negatively affect bacterial growth, resulting in incomplete mapping of the full spectrum of integrants.Vector genome integration has been associated with adverse events; integrating ␥-retroviral vectors were implicated in the clonal expansion of transduced cells in 3 clinical studies, 2 for X-linked severe combined immunodeficiency 10,11 and the other for chronic granulomatous disease. 12,13 Although AAV vectors integrate at a much lower frequency than retroviral vectors, low-level AAV vector integration in transduced cells may still be a concern. A compelling argument supporting low genotoxic risk of AAV vectors comes from long-term follow-up of liver-directed AAVmediated gene transfer in canine and murine models. Of 77 dogs receiving AAV vector at doses up to 3.4 ϫ 10 12 vector genomes(vg)/kg and followed for Յ 10 years, none developed liver tumors as assayed by ultrasound, computed tomographic (CT) scan, and magnetic resonance imaging (MRI) 14,15 (K.A.H., V.R.A., and Timothy C. Nichols, unpublished data, October 15, 2010). Similarly, Ͼ 300 mice receiving AAV vectors with a therapeutic transgene at doses up to 4 ϫ 10 13 vg/kg and followed Յ 14 months have not shown a difference in tumor incidence compared with control mice. 16,17 However, a study by one group reported an increase in tumor incidence that was attributed to AAV vectors. 18 These investigators reported that administration of an AAV serotype 2 (AAV2) vector encoding ␤-glucuronidase in neonatal mice resulted in a significant increase in incidence of hepatocellular carcinoma (HCC), a tumor commonly fou...

A hairpin pyrrole-imidazole polyamide (1) targeted to the androgen receptor consensus half-site was found to exert antitumor effects against prostate cancer xenografts. A previous animal study showed that 1, which has a chiral amine at the α-position of the γ-aminobutyric acid turn (γ-turn), did not exhibit toxicity at doses less than 10 mg/kg. In the same study, a polyamide with an acetamide at the β-position of the γ-turn resulted in animal morbidity at 2.3 mg/kg. To identify structural motifs that cause animal toxicity, we synthesized polyamides 1–4 with variations at the α- and β-positions in the γ-turn. Weight loss, histopathology, and serum chemistry were analyzed in mice post-treatment. While serum concentration was similar for all four polyamides after injection, dose-limiting liver toxicity was only observed for three polyamides. Polyamide 3, with an α-acetamide, caused no significant evidence of rodent toxicity and retains activity against LNCaP xenografts.

The extracellular matrices of a variety of human and animal tissues have been utilized as scaffold materials for soft tissue applications including hernia repair, dermal grafts, and tendon, ligament, and cartilage reconstruction. While these biological scaffolds are expected to demonstrate superior tissue integration, there is very little evidence documenting the properties and behavior of these materials in vivo. This in vivo study investigated four biological scaffolds: two commercially available (a moderately crosslinked scaffold and a noncrosslinked scaffold) and two novel porcine diaphragm biological scaffolds (one with and one without the incorporation of gold nanoparticles). The scaffolds were implanted in a porcine model and evaluated over 1, 3, and 6 months. The moderately crosslinked scaffolds demonstrated the least cellular infiltration and evidence of fibrosis. The noncrosslinked scaffolds demonstrated the greatest cellular infiltration, but these scaffolds were delaminated and exhibited a rapid loss of integrity. The porcine diaphragm scaffolds with and without nanoparticles showed evidence of tissue remodeling and cellular infiltration, with no evidence of encapsulation. While there were no significant differences in the performance of the two novel scaffolds, the gold nanoparticle scaffold typically exhibited higher cellular infiltration. This study demonstrated the potential biocompatibility of a gold nanoparticle-tissue scaffold.

We report the identification, pathogenesis, and transmission of a novel polyomavirus in severe combined immunodeficient F344 rats with null Prkdc and interleukin 2 receptor gamma genes. Infected rats experienced weight loss, decreased fecundity, and mortality. Large basophilic intranuclear inclusions were observed in epithelium of the respiratory tract, salivary and lacrimal glands, uterus, and prostate gland. Unbiased viral metagenomic sequencing of lesioned tissues identified a novel polyomavirus, provisionally named Rattus norvegicus polyomavirus 2 (RatPyV2), which clustered with Washington University (WU) polyomavirus in the Wuki clade of the Betapolyomavirus genus. In situ hybridization analyses and quantitative polymerase chain reaction (PCR) results demonstrated viral nucleic acids in epithelium of respiratory, glandular, and reproductive tissues. Polyomaviral disease was reproduced in Foxn1 nude rats cohoused with infected rats or experimentally inoculated with virus. After development of RatPyV2-specific diagnostic assays, a survey of immune-competent rats from North American research institutions revealed detection of RatPyV2 in 7 of 1,000 fecal samples by PCR and anti-RatPyV2 antibodies in 480 of 1,500 serum samples. These findings suggest widespread infection in laboratory rat populations, which may have profound implications for established models of respiratory injury. Additionally, RatPyV2 infection studies may provide an important system to investigate the pathogenesis of WU polyomavirus diseases of man.

The purpose of this study was: aim 1) compare insulin and leucine serum responses after feeding a novel hydrolyzed whey protein (WPH)-based supplement versus a whey protein isolate (WPI) in rats during the post-absorptive state, and aim 2) to perform a thorough toxicological analysis on rats that consume different doses of the novel WPH-based supplement over a 30-day period. In male Wistar rats (~250 g, n = 40), serum insulin and leucine concentrations were quantified up to 120 min after one human equivalent dose of a WPI or the WPH-based supplement. In a second cohort of rats (~250 g, n = 20), we examined serum/blood and liver/kidney histopathological markers after 30 days of feeding low (1human equivalent dose), medium (3 doses) and high (6 doses) amounts of the WPH-based supplement. In aim 1, higher leucine levels existed at 15 min after WPH vs. WPI ingestion (p = 0.04) followed by higher insulin concentrations at 60 min (p = 0.002). In aim 2, liver and kidney histopathology/toxicology markers were not different 30 days after feeding with low, medium, high dose WPH-based supplementation or water only. There were no between-condition differences in body fat or lean mass or circulating clinical chemistry markers following the 30-day feeding intervention in aim 2. In comparison to WPI, acute ingestion of a novel WPH-based supplement resulted in a higher transient leucine response with a sequential increase in insulin. Furthermore, chronic ingestion of the tested whey protein hydrolysate supplement appears safe.