BOOK REVIEW

Manual of Canine and Feline Wound Management and Reconstruction. Edited by Fowler D and Williams JM     

Serological characterisation of Haemophilus parasuis isolates from Australian pigs

A total of 31 isolates of Haemophilus parasuis obtained from Australian pigs were serotyped by the Kielstein-Rapp-Gabrielson scheme. The isolates were assigned to serovar 1 (1 isolate), serovar 2 (1 isolate), serovar 4 (4 isolates), serovar 5 (7 isolates), serovar 9 (2 isolates), serovar 10/7 (4 isolates), serovar 12 (1 isolate) and serovar 13 (6 isolates). The remaining 5 isolates could not be assigned to a serovar. Two different serovars (5 and 13) were detected in one herd. The only 2 isolates obtained from clinically normal pigs (from the same herd) were serovar 9. The common serovars were isolated from pigs with pneumonia as well as from pigs with conditions of the Glässer's disease type. The serological heterogeneity amongst Australian isolates of H parasuis has important implications for the use of vaccines to control Glässer's disease.     

Late Holocene climate and cultural changes in the southwestern United States

Columnar stalagmites in caves of the Guadalupe Mountains during the late Holocene record a 4000-year annually resolved climate history for the southwestern United States. Annual banding, hiatuses, and high-precision uranium-series dating show a present day-like climate from 4000 to 3000 years ago, following a drier middle Holocene. A distinctly wetter and cooler period from 3000 to 800 years ago was followed by a period of present day-like conditions, with the exception of a slightly wetter interval from 440 to 290 years before the present. The stalagmite record correlates well with the archaeological record of changes in cultural activities of indigenous people. Such climate change may help to explain evidence of dwelling abandonment and population redistribution.     

Effect of a novel solution for organ preservation on equine large colon in an isolated pulsatile perfusion system

REASONS FOR PERFORMING STUDY: Several therapeutic agents have been tested in models of ischaemia and reperfusion injury (IRI) in equine jejunum, with mixed results. This study was based on the use of an organ perfusion solution (OPS) designed to protect human allografts from IRI. HYPOTHESIS: A modified OPS can preserve the integrity of equine large colon during 12 h of isolated pulsatile perfusion, in the absence of oxygen and blood. METHODS: Segments of large colon were removed from anaesthetised horses, the contents removed and the mucosa rinsed with 0.9% saline. Experimental segments were perfused for 12 h with one litre modified OPS (n = 7) delivered by pulsatile flow through an extracorporeal circuit. Control segments (n = 4) were perfused on the same circuit with one litre of autologous blood. Vascular resistance, flow and pressure were measured serially, and aliquots of OPS and blood drawn hourly for routine biochemical analyses. Mucosal biopsies of the experimental and control segments were taken at 0, 6 and 12 h and in vivo mucosal tissue at 0 h for baseline comparison. All biopsies underwent histomorphometric analysis and immunohistochemical assessment of calprotectin activity. RESULTS: All colon segments were machine perfused without technical complications. Vascular and biochemical indices remained constant over 12 h in the OPS group, and were constant over 6 h in the control group, but deteriorated later. Mucosal integrity, expression of cyclooxygenases-1 and -2, and expression of mucosal calprotectin were unchanged in the OPS group compared with the baseline tissues, and mucosal integrity was superior to the control tissues. CONCLUSIONS: A modified OPS designed to target specific pathways of damage from IRI can preserve colonic mucosal integrity for 12 h in the absence of blood and oxygen.     

Detection of calprotectin and its correlation to the accumulation of neutrophils within equine large colon during ischaemia and reperfusion

REASON FOR PERFORMING STUDY: The cytosolic protein complex, calprotectin, is abundant in neutrophils and could be used to improve the ability to localise and assess neutrophil infiltration in the equine intestine during ischaemia and reperfusion (I/R), but further study is required. OBJECTIVES: To assess the number of calprotectin-containing cells by immunohistochemistry in correlation with direct counting and scoring of neutrophils in the equine colon during I/R. METHODS: One and 2 h ischaemia of the left dorsal colon were induced, followed by 30 min reperfusion under general anaesthesia or by 18 h reperfusion after anaesthetic recovery. Biopsies were processed for light microscopy and stained with H/E for detection of neutrophils. To identify calprotectin-containing cells, immunohistochemistry was performed on formalin-fixed tissues with the murine MAC 387 antibody and a biotin-free peroxidase staining procedure. The number of neutrophils within submucosal venules and the colonic mucosa were calculated and compared with the number of calprotectin-positive cells. RESULTS: The number of calprotectin-positive cells within submucosal venules and within the colonic mucosa correlated significantly with the accumulation of neutrophils within the corresponding tissue segments. Within the submucosal venules, both calprotectin-positive cells and H/E-stained neutrophils increased with duration of ischaemia and peaked after 30 min of reperfusion. After 18 h reperfusion the number of these cells declined within the vessels. After 2 h ischaemia, neutrophils started to migrate into the mucosa towards the epithelium, with a significant increase over time during reperfusion, and peak infiltration after 18 h reperfusion. CONCLUSIONS: Neutrophil infiltration into the colon after I/R is a time-dependent process, involving migration through the submucosa towards the epithelium.     

Age and evolution of the Grand Canyon revealed by U-Pb dating of water table-type speleothems

The age and evolution of the Grand Canyon have been subjects of great interest and debate since its discovery. We found that cave mammillaries (water table indicator speleothems) from nine sites in the Grand Canyon showed uranium-lead dating evidence for an old western Grand Canyon on the assumption that groundwater table decline rates are equivalent to incision rates. Samples in the western Grand Canyon yielded apparent water table decline rates of 55 to 123 meters per million years over the past 17 million years, in contrast to eastern Grand Canyon samples that yielded much faster rates (166 to 411 meters per million years). Chronology and inferred incision data indicate that the Grand Canyon evolved via headward erosion from west to east, together with late-stage ( approximately 3.7 million years ago) accelerated incision in the eastern block.     

Echinococcus granulosus in the Northern Territory,Australia: hydatid disease reported in beef cattle from the region

Hydatid disease in beef cattle has been reported to be widespread throughout Australia, but cattle bred and raised in the Northern Territory were previously believed to be free of the disease. Between 2010 and 2016, 1061 cattle from the Northern Territory were slaughtered at a New South Wales abattoir and inspected for hydatid disease. The proportion of cattle reported infected with hydatid disease was 3.5%. Individual cattle identification numbers indicated that the cattle included in the study had most likely remained within the Northern Territory from birth until immediately prior to slaughter, so were assumed to have become infected within the region. We suspect that the sylvatic cycle of Echinococcus granulosus transmission could be responsible for infection of cattle in this region.