Adenovirus-mediated gene therapy to liver grafts: successful gene transfer by donor pretreatment

BACKGROUND: We have previously shown excellent adenoviral (Ad) gene transfection to transplanted liver grafts with the clamp technique (CT) where viral vector was delivered ex vivo and trapped in cold preserved liver grafts. In this study, we adopted a new gene therapy approach to achieve early transgene expression by donor pretreatment with viral vector and compared the efficacy of these two methods by using Ad vector encoding enhanced green fluorescent protein (AdEGFP) marker gene. METHODS: AdEGFP (1 x 10(9)plaque forming units) was delivered to the liver grafts by: (1) single intravenous injection to donor Lewis rats 48 hours before harvesting, (2) ex vivo cold infusion into the harvested liver with CT, or (3) a combination of both methods. Liver grafts were stored in University of Wisconsin solution at 4 degrees C for 18 hours and then orthotopically transplanted into syngeneic recipients, and the expression of EGFP was studied. RESULTS: With intravenous pretreatment of donor liver grafts, EGFP-expressing cells were detected as early as 3 hours after transplant, and moderate expression was seen by 12 hours. In contrast, EGFP was not detected until 12 to 24 hours after transplant with CT. High levels of EGFP-producing cells were seen with each technique at 7 days ( approximately 30% transfection efficiency). A combination of both methods did not enhance infectivity. Liver preservation injury was comparable between groups. CONCLUSIONS: Gene transfer by donor pretreatment with AdEGFP induces early and efficient gene transduction to liver grafts compared with back-table delivery with CT. This method is simple and provides early transgene expression in liver grafts that potentially could be used to deliver genes to decrease preservation injury or rejection.     

Video-fluoroscopic study of swallowing in children with neurodevelopmental disorders

BACKGROUND: Children with neurodevelopmental disorders can have feeding problems. Malnutrition and recurrent aspiration pneumonia can increase the risk of morbidity and mortality. Video-fluoroscopic study of swallowing (VFSS) is essential in understanding the pathological mechanisms involved during swallowing. METHODS: The aim of the present study was to assess the role of VFSS in assessment and management of four children with various neurodevelopmental disorders in a multidisciplinary feeding team. We describe the team approach, with the participation of child neurologist, radiologist with the rehabilitation team including the speech therapist, occupational therapist and dietician, in the assessment and plan of management. RESULTS: Video-fluoroscopic study of swallowing had been useful in assessing the type of swallowing problems with treatment goals targeted to the basic underlying pathophysiological mechanism. CONCLUSION: A child neurologist should be involved in the multidisciplinary oromotor rehabilitation program for neurologically impaired children with feeding problems.     

Cholinesterase inhibition by potato glycoalkaloids slows mivacurium metabolism

BACKGROUND: The duration of action for many pharmaceutical agents is dependent on their breakdown by endogenous hydrolytic enzymes. Dietary factors that interact with these enzyme systems may alter drug efficacy and time course. Cholinesterases such as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) hydrolyze and inactivate several anesthetic drugs, including cocaine, heroin, esmolol, local ester anesthetics, and neuromuscular blocking drugs. Natural glycoalkaloid toxins produced by plants of the family Solanaceae, which includes potatoes and tomatoes, inhibit both AChE and BuChE. Here the authors assess the extent to which two solanaceous glycoalkaloids (SGAs), alpha-solanine and alpha-chaconine, can alter the effects of neuromuscular blocking drugs and cholinesterase inhibitors in vivo and in vitro. METHODS: Inhibition of purified human AChE and BuChE by SGAs, neuromuscular blocking drugs, and cholinesterase inhibitors was assessed by an in vitro colorimetric cholinesterase assay. In vivo experiments were carried out using anesthetized rabbits to test whether SGAs affect recovery from mivacurium-induced paralysis. RESULTS: SGAs inhibited human BuChE at concentrations similar to those found in serum of individuals who have eaten a standard serving of potatoes. Coapplication of SGAs (30-100 nm) with neuromuscular blocking drugs and cholinesterase inhibitors produced additive cholinesterase inhibition. SGA administration to anesthetized rabbits inhibited serum cholinesterase activity and mivacurium hydrolysis. In addition, SGA prolonged the time needed for recovery from mivacurium-induced paralysis (149 +/- 12% of control; n = 12). CONCLUSIONS: These findings support the hypothesis that inhibition of endogenous enzyme systems by dietary factors can influence anesthetic drug metabolism and duration of action. Diet may contribute to the wide variation in recovery time from neuromuscular blockade seen in normal, healthy individuals.     

Domestic dog health worsens with socio-economic deprivation of their home communities

Dogs play an important role in infectious disease transmission as reservoir hosts of many zoonotic and wildlife pathogens. Nevertheless, unlike wildlife species involved in the life cycle of pathogens, whose health status might be a direct reflection of their fitness and competitive abilities, dog health condition could be sensitive to socio-economic factors impacting the well-being of their owners. Here, we compare several dog health indicators in three rural communities of Panama with different degrees of socio-economic deprivation. From a total of 78 individuals, we collected blood and fecal samples, and assessed their body condition. With the blood samples, we performed routine hematologic evaluation (complete blood counts) and measured cytokine levels (Interferon-γ and Interleukin-10) through enzyme-linked immunosorbent assays. With the fecal samples we diagnosed helminthiases. Dogs were also serologically tested for exposure to Trypanosoma cruzi and canine distemper virus, and molecular tests were done to assess T. cruzi infection status. We found significant differences between dog health measurements, pathogen prevalence, parasite richness, and economic status of the human communities where the dogs lived. We found dogs that were less healthy, more likely to be infected with zoonotic pathogens, and more likely to be seropositive to canine distemper virus in the communities with lower economic status. This study concludes that isolated communities of lower economic status in Panama may have less healthy dogs that could become major reservoirs in the transmission of diseases to humans and sympatric wildlife.