The cost of animal research.

The US biomedical research community has long debated how to bill different types of animal research costs. Specifically, which aspects of animal research should be charged as direct costs, and which should be charged as indirect (or facilities and administrative) costs? In this paper, the author describes why the community has yet to clearly define what constitutes indirect costs. He then suggests how researchers, administrators and government officials can categorize different aspects of animal research as direct or indirect costs.

Fecal corticoid metabolites in aged male and female rats after husbandry-related disturbances in the colony room.

We applied novel noninvasive fecal steroid measures to characterize aged rats' responses to a series of common animal room disturbances, including a direct comparison of male and female immunoreactive corticosterone metabolites in feces. The fecal measure provides a unique method to measure the physiologic responses of laboratory animals to altered husbandry procedures. This assay is noninvasive and, because rodents produce fecal pellets throughout the day, long-term monitoring can be conducted to capture abnormal levels associated with alterations in husbandry procedures. Over a 3-h period, 10 male and 10 female Fischer 344 rats (age, 82 wk) were exposed to a series of events that can occur in a colony housing room (keys jingling, cage lids opening, alteration of the light cycle). Fecal samples were collected at timed intervals on the day before and several days after the exposure, extracted, and analyzed for fecal corticoid metabolites by use of a commercial enzyme immunoassay. Fecal metabolites in these aged rats were elevated 3- to 5-fold above baseline levels approximately 20 h after exposure to the experimental events. Overall, we detected more immunoreactive fecal corticoid metabolites in feces from male rats than female rats, even though female rats normally secrete greater amounts of glucocorticoids into circulation. Our results indicate that this assay can be used to identify marked elevations in corticoid metabolite levels after alterations in laboratory husbandry procedures. We discuss the implications of these findings for animal researchers and those involved in animal husbandry.

Characterization of immune responses during regression of rabbit oral papillomavirus infections.

Rabbit oral papillomavirus (ROPV) is a mucosatropic papillomavirus that causes small benign discrete papillomas within the oral cavity of domestic rabbits. The goal of this study was to characterize the immune cell infiltrate over the course of regression of oral papillomas. ROPV-infected oral tissues were harvested at various time points after infection and analyzed by immunohistochemistry for papilloma morphology, viral capsid proteins, and associated immune infiltrates. The results of this study indicated that the L1 and L2 viral capsid proteins were lost rapidly at a time that coincided with an inflammatory response from the rabbit. This inflammatory response began with a rapid rise in numbers of CD11c+ cells at early regression. CD11c+ cells continued to increase in frequency through mid-regression and remained the most-represented cell through late regression. The initial rise in CD11c+ cells was followed by an infiltrate containing increased numbers of activated T cells, including CD4+ and CD25+ cells, during mid-regression. Mid-regression coincided spatially with a loss of viral capsid stain, suggesting that immune cells or cytokines or both were playing a key role in clearance of the papillomas. CD8+ cells increased at the lowest rate and were at low levels in the papilloma epidermis even at mid-regression. All cell types decreased by late regression. CD11c+ and major histocompatibility class II+ cells were the last populations of cells to decrease in number.

Surfactant protein A and B genetic variants predispose to idiopathic pulmonary fibrosis.

Derangement in pulmonary surfactant or its components and alveolar collapse are common findings in idiopathic pulmonary fibrosis (IPF). Surfactant proteins play important roles in innate host defense and normal function of the lung. We examined associations between IPF and genetic polymorphic variants of surfactant proteins, SP-A1, SP-A2, SP-B, SP-C, and SP-D. One SP-A1 (6A(4)) allele and single nucleotide polymorphisms (SNPs) that characterize the 6A(4) allele, and one SP-B (B1580_C) were found with higher frequency ( P

Mucosally-derived HPV-40 can infect both human genital foreskin and cutaneous hand skin tissues grafted into athymic mice.

HPV-40 is a rare HPV type that has been detected only in genital mucosal tissues. This HPV type is very closely related to HPV-7, which has a predominantly cutaneous tissue tropism. We have shown, previously, that an isolate of HPV-40 (described here as HPV-40(Hershey) or HPV-40(H)) productively infected genital tissues. In this study, HPV-40(H) was tested for productive infection of cutaneous tissue. Fetal hand skin fragments were incubated with infectious HPV-40(H) and implanted subrenally into athymic mice. After 120 days, xenografts showed morphological changes consistent with HPV-40(H) infection and were HPV-40 DNA in situ positive and capsid antigen positive. The results demonstrated that hand skin can support HPV-40(H) infection thereby indicating that this viral type has the capacity to infect both genital mucosal and cutaneous tissues.

Naltrexone, an opioid antagonist, facilitates reepithelialization of the cornea in diabetic rat.

Ulcers and erosions of the corneal epithelium, as well as delays in resurfacing of the cornea after wounding, are major causes of ocular morbidity and visual loss in diabetes. To study whether intervention by the opioid antagonist naltrexone (NTX; 30 mg/kg, twice daily) can restore reepithelialization in diabetic cornea, we induced diabetes in rats by intravenous injection of 65 mg/kg streptozotocin. After confirmation of diabetes, 5-mm-diameter epithelial defects that did not include the limbus were created by mechanical scraping of the cornea. At 4 and 8 weeks, corneal reepithelialization was markedly subnormal, with delays ranging from 11% to 17-fold in the diabetic animals compared with control counterparts. Rats that were diabetic for 8 weeks also had a significant decrease in the incidence of complete wound closure. At 4 and 8 weeks, diabetic animals that were receiving NTX had an acceleration in reepithelialization compared with diabetic animals that were receiving vehicle and even surpassed controls. DNA synthesis in the corneal epithelium of diabetic rats was decreased up to 90% of control levels, and NTX exposure of diabetic subjects elevated the labeling index by up to eightfold from diabetic animals that were receiving vehicle. Opioid growth factor and opioid growth factor receptor distribution were comparable in diabetic and control animals. These results indicate a delay in reepithelialization that is dependent on the duration of diabetes and that intervention of endogenous opioid-receptor interfacing with an opioid antagonist can facilitate the process of wound healing.

Angiopoietin-1 and VEGF in vascular development and angiogenesis in hypoplastic lungs.

We hypothesized that exposure of murine fetuses to environmental toxins, such as nitrofen, during early embryogenesis alters vasculogenesis. To address our hypothesis, we assessed protein levels of endothelial cell-selective angiogenic factors: angiopoietin (ANG)-1, vascular endothelial growth factor (VEGF), and mediator of VEGF signaling, VEGF receptor-2 [fetal liver kinase (Flk)-1], a transmembrane receptor tyrosine kinase. VEGF and Flk-1 proteins were lower in hypoplastic lungs from pseudoglandular to alveolar stages than in normal lungs at equivalent developmental time points significant for induction of pulmonary vasculogenesis and angiogenesis. ANG-1 protein was higher in hypoplastic lungs than in normal lungs at all the developmental stages considered in this study, i.e., pseudoglandular, canalicular, saccular, and alveolar stages. We assessed exogenous VEGF-mediated endothelial cell response on extracellular signal-regulated kinase (ERK) 1/2, also referred to as p44/42 mitogen-activated protein kinase. Hypoplastic lungs had more elevated ERK 1/2 protein than normal developing lungs. Exposure to exogenous VEGF activated ERK 1/2 in normal developing lungs but not in hypoplastic lungs. Our results suggest that in hypoplastic lungs: 1) low VEGF signifies negative effects on vasculogenesis/angiogenesis and indicates altered endothelial-mesenchymal interactions; 2) increased ANG-1 protein may be required to maintain vessel integrity and quiescence; and 3) regulation of ERK 1/2 protein is affected in hypoplastic lungs. We speculate that extensive remodeling of blood vessels in hypoplastic lungs may occur to compensate for structurally and functionally defective vasculature.