Morphometric Examination of the Equine Adult and Foal Lung

To understand the mechanisms of airway inflammation associated with equine diseases such as Rhodococcus equi infection, we must identify baseline “normal” structural characteristics of the horse lung. To develop a detailed understanding of the morphology of the horse lung, we adapted and applied stereological methods to the lungs from healthy adult horses (N = 4) and 1‐day (N = 5) and 30‐day (N = 5) old foals. The left lung was fixed in situ by intrabronchial instillation of glutaraldehyde/paraformaldehyde fixative at 25 cm H₂O column and sampled using a fractionator design followed by embedding in glycol methacrylate. The lung was characterized into parenchyma and non‐parenchyma, where median parenchymal density was 81.0% in 1‐day‐old foals, 84.4% in 30‐day‐old foals and 93.7% in adult lungs. The median volume density of alveolar airspace per lung was 45.9% in 1‐day‐old, 55.5% in 30‐day and 66.9% in adult horse lungs. The median alveolar surface area increased with age, from 205.3 m², 258.2 m², and 629.9 m² in 1‐day‐old foals, 30‐day‐old foals, and adults, respectively. While the median alveolar surface density decreased with age, the mean linear intercept (mean free distance within acinar airspaces) increased with age. Alveolar surface area was greater than endothelial surface area within each lung. The ratio between alveolar and endothelial surface density remains unchanged with age. The median endothelium surface area was 106.2 m² in 1‐day, 147.5 m² in 30‐day, and 430 m² in adult lungs. The data suggest the foal lung is functionally developed and postnatal lung development and remodelling is driven by alveolar expansion paralleled with angiogenesis. Anat Rec, 297:1950–1962, 2014. © 2014 Wiley Periodicals, Inc.     

Specific recognition of influenza virus polymerase protein (PB1) by a murine cytotoxic T-cell clone

Cytotoxic T-cell clones were raised in CBA mice that recognised both A/X31 and A/JAP/305/1957 influenza virus. Here, we describe one CTL clone that recognises target cells infected with a recombinant vaccinia virus expressing influenza PB1.     

Calmodulin antagonist trifluoperazine inhibits polyamine biosynthesis and liver regeneration

Polyamines are essential for cell growth and differentiation. Trifluoperazine (TFP) is a potent, competitive inhibitor of the calcium-calmodulin complex. TFP, when given to rats after partial hepatectomy, causes a significant decrease in DNA synthesis. The purpose of this study was to examine the effects of TFP on polyamine biosynthesis and on liver regeneration after partial hepatectomy. TFP (60 mg/kg, bodyweight) or saline control was administered to 80 male Sprague-Dawley rats 2 h before, 2 h after, or at the time of hepatectomy. Polyamines (putrescine, spermidine and spermine) were measured at the time of hepatectomy, and at 6, 24, 48, and 72 h after hepatectomy. TFP, when it was administered either 2 h before or at time of hepatectomy, blocked increases in putrescine that are seen normally at 6 h after hepatectomy. When TFP was given at the time of partial hepatectomy, putrescine was increased at 24 h, and then returned to normal levels at 72 h. Spermidine was inhibited at 24 h, but not at 48 and 72 h. Spermine was not significantly altered at any time. The administration of TFP 2 h after hepatectomy did not significantly alter concentrations of polyamines. The weight of regenerating liver was decreased by TFP at 48 h (23 per cent) and 72 h (22 per cent) after hepatectomy. These findings provide evidence that the calcium-calmodulin complex is required for the synthesis of liver polyamines before liver regeneration can proceed.     

Corridors affect plants,animals, and their interactions in fragmented landscapes

Among the most popular strategies for maintaining populations of both plants and animals in fragmented landscapes is to connect isolated patches with thin strips of habitat, called corridors. Corridors are thought to increase the exchange of individuals between habitat patches, promoting genetic exchange and reducing population fluctuations. Empirical studies addressing the effects of corridors have either been small in scale or have ignored confounding effects of increased habitat area created by the presence of a corridor. These methodological difficulties, coupled with a paucity of studies examining the effects of corridors on plants and plant-animal interactions, have sparked debate over the purported value of corridors in conservation planning. We report results of a large-scale experiment that directly address this debate. In eight large-scale experimental landscapes that control for patch area and test alternative mechanisms of corridor function, we demonstrate that corridors not only increase the exchange of animals between patches, but also facilitate two key plant-animal interactions: pollination and seed dispersal. Our results show that the beneficial effects of corridors extend beyond the area they add, and suggest that increased plant and animal movement through corridors will have positive impacts on plant populations and community interactions in fragmented landscapes.