Deleterious effects of plasma-derived cellular debris in a porcine model of hemorrhagic shock

BACKGROUND

Recent studies identify large quantities of inflammatory cellular debris within Fresh Frozen Plasma (FFP). As FFP is a mainstay of hemorrhagic shock resuscitation, we used a porcine model of hemorrhagic shock and ischemia/reperfusion to investigate the inflammatory potential of plasma-derived cellular debris administered during resuscitation.

METHODS

The porcine model of hemorrhagic shock included laparotomy with 35 % hemorrhage (Hem), 45 min of ischemia from supraceliac aortic occlusion with subsequent clamp release (IR), followed by protocolized resuscitation for 6 h. Cellular debris (Debris) was added to the resuscitation phase in three groups. The four groups consisted of Hem + IR (n = 4), Hem + IR + Debris (n = 3), Hem + Debris (n = 3), and IR + Debris (n = 3). A battery of laboratory, physiologic, cytokine, and outcome data were compared between groups.

RESULTS

As expected, the Hem + IR group showed severe time dependent decrements in organ function and physiologic parameters. All animals that included both IR and Debris (Hem + IR + Debris or IR + Debris) died prior to the six-hour end point, while all animals in the Hem + IR and Hem + Debris survived. Cytokines measured at 30-60 min after initiation of resuscitation revealed significant differences in IL-18 and IL-1β between all groups.

CONCLUSIONS

Ischemia and reperfusion appear to prime the immune system to the deleterious effects of plasma-derived cellular debris. In the presence of ischemia and reperfusion, this model showed the equivalency of 100 % lethality when resuscitation included quantities of cellular debris at levels routinely administered to trauma patients during transfusion of FFP. A deeper understanding of the immunobiology of FFP-derived cellular debris is critical to optimize resuscitation for hemorrhagic shock.

Alteration of mitochondrial function and insulin sensitivity in primary mouse skeletal muscle cells isolated from transgenic and knockout mice: role of ogg1

Recent evidence has linked mitochondrial dysfunction and DNA damage, increased oxidative stress in skeletal muscle, and insulin resistance (IR). The purpose of this study was to determine the role of the DNA repair enzyme, human 8-oxoguanine DNA glycosylase/apurinic/apyrimidinic lyase (hOGG1), on palmitate-induced mitochondrial dysfunction and IR in primary cultures of skeletal muscle derived from hind limb of ogg1(-/-) knockout mice and transgenic mice, which overexpress human (hOGG1) in mitochondria (transgenic [Tg]/MTS-hOGG1). Following exposure to palmitate, we evaluated mitochondrial DNA (mtDNA) damage, mitochondrial function, production of mitochondrial reactive oxygen species (mtROS), mitochondrial mass, JNK activation, insulin signaling pathways, and glucose uptake. Palmitate-induced mtDNA damage, mtROS, mitochondrial dysfunction, and activation of JNK were all diminished, whereas ATP levels, mitochondrial mass, insulin-stimulated phosphorylation of Akt (Ser 473), and insulin sensitivity were increased in primary myotubes isolated from Tg/MTS-hOGG1 mice compared to myotubes isolated from either knockout or wild-type mice. In addition, both basal and maximal respiratory rates during mitochondrial oxidation on pyruvate showed a variable response, with some animals displaying an increased respiration in muscle fibers isolated from the transgenic mice. Our results support the model that DNA repair enzyme OGG1 plays a pivotal role in repairing mtDNA damage, and consequently, in mtROS production and regulating downstream events leading to IR in skeletal muscle.

Development of novel O-polysaccharide based glycoconjugates for immunization against glanders

Burkholderia mallei the etiologic agent of glanders, causes severe disease in humans and animals and is a potential agent of biological warfare and terrorism. Diagnosis and treatment of glanders can be challenging, and in the absence of chemotherapeutic intervention, acute human disease is invariably fatal. At present, there are no human or veterinary vaccines available for immunization against disease. One of the goals of our research, therefore, is to identify and characterize protective antigens expressed by B. mallei and use them to develop efficacious glanders vaccine candidates. Previous studies have demonstrated that the O-polysaccharide (OPS) expressed by B. mallei is both a virulence factor and a protective antigen. Recently, we demonstrated that Burkholderia thailandensis, a closely related but non-pathogenic species, can be genetically manipulated to express OPS antigens that are recognized by B. mallei OPS-specific monoclonal antibodies (mAbs). As a result, these antigens have become important components of the various OPS-based subunit vaccines that we are currently developing in our laboratory. In this study, we describe a method for isolating B. mallei-like OPS antigens from B. thailandensis oacA mutants. Utilizing these purified OPS antigens, we also describe a simple procedure for coupling the polysaccharides to protein carriers such as cationized bovine serum albumin, diphtheria toxin mutant CRM197 and cholera toxin B subunit. Additionally, we demonstrate that high titer IgG responses against purified B. mallei LPS can be generated by immunizing mice with the resulting constructs. Collectively, these approaches provide a rational starting point for the development of novel OPS-based glycoconjugates for immunization against glanders.

Measurement of fetal biparietal diameter in owl monkeys (Aotus nancymaae)

Owl monkeys are New World primates frequently used in biomedical research. Despite the historical difficulty of breeding owl monkeys in captivity, several productive owl monkey breeding colonies exist currently. The animals in the colony we describe here are not timed-pregnant, and determination of gestational age is an important factor in prenatal care. Gestational age of human fetuses is often determined by using transabdominal measurements of fetal biparietal diameter. The purpose of this study was to correlate biparietal diameter measurements with gestational age in owl monkeys. We found that biparietal diameter can be used to accurately predict gestational age in owl monkeys.

Restasis for the treatment of 'dry eye' in Aotus nancymaae

BACKGROUND

This case report describes the treatment of three male owl monkeys (Aotus nancymaae) diagnosed with chronic dry eye with a topical cyclosporine product, Restasis, approved for use in humans. These owl monkeys had ocular disease resulting from procedures performed at a biotechnology company. They were moved to the Center for Neotropical Primate Research and Resources at University of South Alabama to be incorporated into the breeding colony.

MATERIALS AND METHODS

Schirmer tear testing was performed initially and during the course of treatment to monitor efficacy of twice daily administered Restasis. The goals of treatment were to reduce pain and/or distress and if possible to quantitatively increase tear production.

RESULTS AND DISCUSSION

All animals had improvements in conjunctival inflammation and had an increase in tear production.

Ultrasonographic monitoring of a spontaneous abortion in an owl monkey (Aotus nancymaae)

This case report describes the ultrasonographic findings during an idiopathic spontaneous abortion in an owl monkey. The female owl monkey presented for a transabdominal ultrasonogram to evaluate her pregnancy. This evaluation is a routine monitoring procedure in our owl monkey breeding colony. Although the fetus and placenta appeared normal at the initial scan, no fetal heartbeat could be detected. We followed the abortion with serial ultrasonographic scans and documented complete involution of the uterus post-abortion.

Ultrasound-guided follicular aspiration in squirrel monkeys

The objective of this study was to test whether ultrasound-guided oocyte retrieval is an effective mechanism for collecting oocytes in squirrel monkeys. Although ultrasound-guided follicular aspiration has been described in Old World primates, oocyte retrieval in New World primates is typically performed via laparoscopy or laparotomy. However, these procedures, especially the first, can be invasive. Ultrasound has been used for pregnancy monitoring in multiple species of primates including Saimiri spp. Transabdominal ultrasound as a diagnostic tool is non-invasive. Transabdominal ultrasound was utilized to visualize ovarian follicles during aspiration under light anesthesia. This procedure resulted in collection of a total of 29 oocytes from six animals with minimal post-procedural pain. Manipulated animals were returned to the social group the same day.

Ovarian stimulation of squirrel monkeys (Saimiri boliviensis boliviensis) using pregnant mare serum gonadotropin

The application of assisted reproductive technologies (ART) to nonhuman primates has created opportunities for improving reproductive management in breeding colonies, and for creation of new animal models by genetic modification. One impediment to the application of ART in Saimiri spp. has been the lack of an effective gonadotropin preparation for ovarian stimulation. Pregnant mare serum gonadotropin (PMSG) is inexpensive and readily available, but its repeated use in rhesus monkeys has been associated with induction of a refractory state. We have compared PMSG to recombinant human follicle stimulating hormone (rhFSH) for controlled ovarian stimulation in Bolivian squirrel monkeys. Groups of mature squirrel monkeys received rhFSH (75 IU daily) or PMSG (250 IU twice daily) by subcutaneous injection for 4 d during the breeding season (November to January) or nonbreeding season (March to September). Serum estradiol (E2) was measured daily. Follicular growth was monitored by abdominal ultrasound. During the breeding season, PMSG induced a higher E2 response than did rhFSH, with mean E2 levels being significantly higher within 3 d of stimulation. Superior follicular development in PMSG animals was confirmed by abdominal ultrasonography. During the nonbreeding season, PMSG elicited a similar increase in serum E2 levels despite the fact that basal serum E2 is typically low during the nonbreeding season. Repeated use of PMSG (< or = 3 cycles of administration) produced no attenuation of the E2 response. We conclude that PMSG is highly effective for repeated cycles of controlled ovulation stimulation in the squirrel monkey.

Synergistic heterozygosity in mice with inherited enzyme deficiencies of mitochondrial fatty acid beta-oxidation

We have used mice with inborn errors of mitochondrial fatty acid beta-oxidation to test the concept of synergistic heterozygosity. We postulated that clinical disease can result from heterozygous mutations in more than one gene in single or related metabolic pathways. Mice with combinations of mutations in mitochondrial fatty acid beta-oxidation genes were cold challenged to test their ability to maintain normal body temperature, a sensitive indicator of overall beta-oxidation function. This included mice of the following genotypes: triple heterozygosity for mutations in very-long-chain acyl CoA dehydrogenase, long-chain acyl CoA dehydrogenase, and short-chain acyl CoA dehydrogenase genes (VLCAD+/-//LCAD+/-//SCAD+/-); double heterozygosity for mutations in VLCAD and LCAD genes (VLCAD+/-//LCAD+/-); double heterozygosity for mutations in LCAD and SCAD genes (LCAD+/-//SCAD+/-); single heterozygous mice (VLCAD+/-, LCAD+/-, SCAD+/-) and wild-type. We found that approximately 33% of mice with any of the combined mutant genotypes tested became hypothermic during a cold challenge. All wild-type and single heterozygous mice maintained normal body temperature throughout a cold challenge. Despite development of hypothermia in some double heterozygous mice, blood glucose concentrations remained normal. Biochemical screening by acylcarnitine and fatty acid analyses demonstrated results that varied by genotype. Thus, physiologic reduction of the beta-oxidation pathway, characterized as cold intolerance, occurred in mice with double or triple heterozygosity; however, the derangement was milder than in mice homozygous for any of these mutations. These results substantiate the concept of synergistic heterozygosity and illustrate the potential complexity involved in diagnosis and characterization of inborn errors of fatty acid metabolism in humans.

Influence of dietary fatty acid chain-length on metabolic tolerance in mouse models of inherited defects in mitochondrial fatty acid beta-oxidation

Fasting-induced metabolic disease of all inherited deficiencies of the acyl-CoA dehydrogenases is characterized by hypoglycemia, hypoketonemia, and organic aciduria. Mice with these enzyme deficiencies are cold intolerant. To evaluate the potential role that dietary fatty acid chain-length has on a patient's ability to compensate during a metabolic challenge, we fed long-chain acyl CoA dehydrogenase (LCAD) deficient and short-chain acyl CoA dehydrogenase (SCAD) deficient mice a diet rich in medium-chain triglycerides (MCT) or long-chain triglycerides (LCT). To elucidate the importance of maintaining adequate serum glucose concentrations on compensation mechanisms during metabolic challenge, we treated LCAD-/- mice with a solution of 12.5% glucose or saline prior to fasting and a cold-challenge. We found that feeding SCAD deficient mice the LCT diet from weaning increased survival from 40 to 94% during metabolic challenge of cold tolerance. In contrast, there was no benefit to feeding the MCT diet at weaning to LCAD-/- mice; however, there was significant benefit when LCAD-/- mice were fed the MCT diet from the beginning of gestation. Survival during cold-challenge increased from 50 to 93%. In the LCAD-/- mice treated with glucose, despite maintaining serum glucose concentrations at normal or higher concentrations, the LCAD-/- mice were still unable to compensate during metabolic challenge. These results indicate the important influences dietary fatty acids may have by providing enhanced metabolic tolerance in patients with inborn errors of fatty acid oxidation. Furthermore, these studies demonstrate that there may be crucial variables involved in the treatment of these patients, including the patient's specific enzyme deficiency, the quantity and chain-length of dietary fat, which may provide positive effects, as well as the time in development when it was administered.

Dietary phytoestrogens increase metabolic resistance (cold tolerance) in long-chain acyl-CoA dehydrogenase-deficient mice

We evaluated the role of dietary phytoestrogens (PE) in the disease phenotype of cold intolerance that characterizes long-chain acyl-CoA dehydrogenase-deficient (LCAD-/-) mice, a model of inborn errors of mitochondrial fatty acid beta-oxidation. Male LCAD-/- mice were fed a standard diet containing endogenous PE, a PE-free diet, or a PE-free diet that was supplemented with genistein (250 microg/g diet). The standard diet did not restore complete cold tolerance, but it provided more resistance (P = 0.004) to cold challenge than the PE-free diet. There was a nonsignificant difference (P < 0.07) between LCAD-/- mice fed the genistein-supplemented diet and those fed the PE-free diet. There were no differences in end-point serum glucose concentrations among the 3 groups. Serum FFA were decreased in LCAD-/- mice fed the standard diet compared with those fed the PE-free diet (P = 0.005) and the diet supplemented with genistein (P < 0.001). Serum triglyceride concentrations were greater (P < 0.05) only in LCAD-/- mice fed the genistein-supplemented diet than those fed the standard diet. These results demonstrate the beneficial effects of dietary PE on metabolic tolerance in LCAD-/- mice. Furthermore, they suggest changes that could improve pediatric formula constituents, especially with regard to management of children with inborn errors of fatty acid oxidation.

Mouse models for disorders of mitochondrial fatty acid beta-oxidation

Mitochondrial beta-oxidation of fatty acids is vital for energy production in periods of fasting and other metabolic stress. Human patients have been identified with inherited disorders of mitochondrial beta-oxidation of fatty acids with enzyme deficiencies identified at many of the steps in this pathway. Although these patients exhibit a range of disease processes, Reye-like illness (hypoketotic-hypoglycemia, hyperammonemia and fatty liver) and cardiomyopathy are common findings. There have been several mouse models developed to aid in the study of these disease conditions. The characterized mouse models include inherited deficiencies of very long-chain acyl-CoA dehydrogenase, long-chain acyl-CoA dehydrogenase, short-chain acyl-CoA dehydrogenase, mitochondrial trifunctional protein-alpha, and medium-/short-chain hydroxyacyl-CoA dehydrogenase. Mouse mutants developed, but presently incompletely characterized as models, include carnitine palmitoyltransferase-1a and medium-chain acyl-CoA dehydrogenase deficiencies. In general, the mouse models of disorders of mitochondrial fatty acid beta-oxidation have shown clinical signs that include Reye-like syndrome and cardiomyopathy, and many are cold intolerant. It is expected that these mouse models will provide vital contributions in understanding the mechanisms of disease pathogenesis of fatty acid oxidation disorders and the development of appropriate treatments and supportive care.

Influence of bovine ampullary and isthmic oviductal fluid on sperm-egg binding and fertilization in vitro

The objective of this study was to determine the effects of oviductal fluid on sperm binding and fertilization in vitro when either bovine oocytes or both spermatozoa and oocytes are incubated in fluid from different regions of the oviduct and at different stages of the oestrous cycle. Oocytes, or oocytes and spermatozoa, were incubated in nonluteal and luteal oviductal fluid obtained from the whole, isthmic or ampullary oviduct of dairy cows. Gametes were washed and coincubated in fertilization medium for 18 h, and then observed for sperm binding and penetration. More spermatozoa bound to oocytes that were preincubated in nonluteal oviductal fluid than to those that were incubated in luteal oviductal fluid; however, there were no differences in fertilization rates between the two treatments. More spermatozoa bound to oocytes incubated in isthmic than in ampullary oviductal fluid. However, if both gametes were incubated in oviductal fluid before their coincubation, binding was higher when both gametes were incubated in ampullary oviductal fluid. By reducing the time of coincubation of spermatozoa with the oocytes, differences in fertilization rates were seen among the various oviductal fluid treatments. At 14 and 16 h of coincubation, more oocytes were fertilized if spermatozoa were preincubated in isthmic oviductal fluid and oocytes were preincubated in ampullary oviductal fluid than if both gametes were incubated in whole or ampullary oviductal fluid. Because both sperm binding to the zona pellucida and fertilization rates were greater in treatments in which gametes were exposed to regional oviductal fluid than when they were incubated in whole oviductal fluid, it is concluded that oviductal fluid from different regions of the bovine oviduct may play different roles in facilitating fertilization.