Successful liver-directed gene delivery by ERCP-guided hydrodynamic injection (with videos).

BACKGROUND AND AIMS: A simple, safe, targeted, and efficient in vivo DNA delivery system is necessary for clinical-grade liver-targeted gene therapy in humans. Intravascular hydrodynamic gene delivery has been investigated in large animal models, but translation to humans has been hampered by its technical challenges, invasiveness, and potential for significant cardiovascular adverse events. We posited that intrabiliary delivery of DNA plasmids via ERCP-guided hydrodynamic injection could overcome these obstacles. METHODS: Twelve pigs (40-50 kg) were divided into 3 groups (4 per group) and survived 21, 30, or 60 days. ERCP was performed by inflating a balloon catheter in the common hepatic duct and creating a closed space between it and the liver parenchyma. Last, a solution composed of plasmid/sleeping beauty (SB) mix was injected under pressure through the catheter into the closed space. Swine were killed at the 3 different time points and liver tissue harvested. Plasmid DNA expression and functional translated protein expression were assessed. RESULTS: ERCP-guided hydrodynamic delivery of naked plasmid DNA facilitated by pCytomegalovirus-Sleep Beauty (pCMV-SB) transposons was technically feasible and devoid of cardiovascular and local adverse events in all 12 pigs. Furthermore, plasmid DNA (both single and combination) was successfully transferred into swine hepatocytes in all 12 pigs. Additionally, stable integration of the DNA constructs in hepatocyte genomic DNA was reliably noted at all 3 time points. In the 4 swine that were kept alive to 60 days, successful genomic integration and subsequent protein expression was observed in the targeted liver tissue. CONCLUSIONS: ERCP-guided hydrodynamic delivery of gene therapy may usher in the next chapter in gene therapy with the potential to impact a variety of single-gene, complex genetic, and epigenetic liver diseases. It also raises the possibility that other nucleic acid therapeutics (microRNA, lncRNA, siRNA, shRNA) could similarly be delivered.

Atresia Ani with Imperforate Anus in a Common Marmoset (Callithrix jacchus).

In November 2015, an 83-d-old juvenile male common marmoset (Callithrix jacchus) in good body condition was found dead in his family cage with no previous premonitory signs. Necropsy revealed a gas-distended abdomen, feces-distended large bowel, and a full-thickness distal colonic perforation resulting in fecal peritonitis. The distal colon ended in a blind pouch at 7 mm prior to the expected anal opening, consistent with atresia ani. Here we present this case, briefly discuss the human and veterinary literature regarding correction of anorectal malformations, and highlight the importance of identifying such devastating congenital defects in breeding colonies while limiting the disruption and handling of seemingly healthy, young NHP raised in a complex social setting.

Comparison of Direct and Indirect Methods of Measuring Arterial Blood Pressure in Healthy Male Rhesus Macaques (Macaca mulatta).

Blood pressure is a critical parameter for evaluating cardiovascular health, assessing effects of drugs and procedures, monitoring physiologic status during anesthesia, and making clinical decisions. The placement of an arterial catheter is the most direct and accurate method for measuring blood pressure; however, this approach is invasive and of limited use during brief sedated examinations. The objective of this study was to determine which method of indirect blood pressure monitoring was most accurate compared with measurement by direct arterial catheterization. In addition, we sought to determine the relative accuracy of each indirect method (compared with direct arterial measurement) at a given body location and to assess whether the accuracy of each indirect method was dependent on body location. We compared direct blood pressure measurements by means of catheterization of the saphenous artery with oscillometric and ultrasonic Doppler flow detection measurements at 3 body locations (forearm, distal leg, and tail base) in 16 anesthetized, male rhesus macaques. The results indicate that oscillometry at the forearm is the best indirect method and location for accurately and consistently measuring blood pressure in healthy male rhesus macaques.

Evaluation of an in vivo model for ventricular shunt infection: a pilot study using a novel antimicrobial-loaded polymer.

OBJECTIVE: Ventricular shunt infection remains an issue leading to high patient morbidity and cost, warranting further investigation. The authors sought to create an animal model of shunt infection that could be used to evaluate possible catheter modifications and innovations. METHODS: Three dogs underwent bilateral ventricular catheter implantation and inoculation with methicillin-sensitive Staphylococcus aureus (S. aureus). In 2 experimental animals, the catheters were modified with a polymer containing chemical "pockets" loaded with vancomycin. In 1 control animal, the catheters were polymer coated but without antibiotics. Animals were monitored for 9 to 11 days, after which the shunts were explanted. MRI was performed after shunt implantation and prior to catheter harvest. The catheters were sonicated prior to microbiological culture and also evaluated by electron microscopy. The animals' brains were evaluated for histopathology. RESULTS: All animals underwent successful catheter implantation. The animals developed superficial wound infections, but no neurological deficits. Imaging demonstrated ventriculitis and cerebral edema. Harvested catheters from the control animal demonstrated > 104 colony-forming units (CFUs) of S. aureus. In the first experimental animal, one shunt demonstrated > 104 CFUs of S. aureus, but the other demonstrated no growth. In the second experimental animal, one catheter demonstrated no growth, and the other grew trace S. aureus. Brain histopathology revealed acute inflammation and ventriculitis in all animals, which was more severe in the control. CONCLUSIONS: The authors evaluated an animal model of ventricular shunting and reliably induced features of shunt infection that could be microbiologically quantified. With this model, investigation of pathophysiological and imaging correlates of infection and potentially beneficial shunt catheter modifications is possible.

Effects of medicated diet to eradicate Helicobacter spp. on growth, pathology, and infection status in Rag1-/- and nude mice.

The use of a commercial 4-drug diet has been shown to eradicate Helicobacter spp. from immunocompetent mice and those with innate immunodeficiencies. However the efficacy of this diet has not been confirmed in mice with altered adaptive immunity. We hypothesized that an 8-wk treatment with medicated diet would eradicate H. hepaticus and H. typhlonius from young naturally infected nude and Rag1 mice lacking functional T cells (Foxn1(nu)) or T and B cells (B6.129S7-Rag1(tm1Mom)/J), respectively. We evaluated helicobacter status, body weight, and gross and histologic changes between medicated and control diet in groups of infected and uninfected mice throughout treatment and at 8 wk after treatment completion. Initial infection status was confirmed by fecal PCR at weaning and 3 wk later, with study initiation in 7-wk-old mice. PCR testing demonstrated that independent of strain and sex, all treated mice tested negative for Helicobacter spp. after 4 wk of treatment and remained negative for the duration of the study. Irrespective of infection status, nude and Rag1 mice fed 8 wk of medicated diet gained less weight than did their untreated controls. Both strains normalized body weight while on control diet for the 8 wk after treatment. Mice fed medicated diet developed severe gastroesophageal hyperkeratosis, suggestive of reduced feed consumption, and enlarged ceca. These conditions improved or resolved after the return to control diet. This report is the first to demonstrate the efficacy and physical effects of providing medicated diet for the eradication of Helicobacter spp. from mice with adaptive immune deficiencies.