Skin Fold Advancement Flaps for Closing Large Sternal and Inguinal Wounds in Cats and Dogs

Skin fold advancement flaps can be created from the elbow and flank folds to close large wounds in the pectoral and inguinal regions of cats and dogs, respectively. The attachments of the laterally facing (outer) and medially facing (inner) layers of the skin fold to the adjacent limb are divided to produce a U-shaped pedicle graft attached to the trunk. This mobilizes skin that can be advanced over large wounds involving the ventral chest or abdomen, or both. The use of skin fold advancement flaps enables direct closure of large skin defects without undue tension and without compromising the mobility of the adjacent limb.     

Association of a xylem-limited bacterium with Sumatra disease of cloves in Indonesia

Sumatra disease is highly destructive in most clove-growing areas of Sumatra and in western parts of Java. Symptoms of leaf-fall and twig die-back, starting in the upper branches, and often associated with wilting, lead to tree death in 6–18 months. Normally, only seedlings and young trees survive. Symptoms are usually more severe and disease spread is more rapid at higher elevations. Patterns of jump-spread suggest that the disease agent is carried via an airborne pathway, possibly by insect vectors. Small, Gram-negative, non-motile, rod-shaped bacteria are consistently associated with the disease. Initial attempts to culture the bacteria in vitro did not succeed. The bacteria are confined within xylem vessels and are found throughout diseased trees. Greyish-brown streaks are present in wood of heavily infected tissues which release a bacterial ooze from cut surfaces; in such tissues many of the vessels are occluded by bacteria embedded in a gelatinous matrix. At the time of first above-ground symptoms, bacteria are already well established in roots and the trunk base, from where they appear to spread upwards in newly formed wood into the crown of the tree. Symptoms are thought to result from root dysfunction and mechanical blockage of the vascular system. All known clove varieties appear equally susceptible.     

Towards Ethically Improved Animal Experimentation in the Study of Animal Reproduction

The ethics of animal-based research is a continuing area of debate, but ethical research protocols do not prevent scientific progress. In this paper, we argue that our current knowledge of the factors that affect reproductive processes provides researchers with a solid foundation upon which they can conduct more ethical research and simultaneously produce data of higher quality. We support this argument by showing how a deep understanding of the genetics, nutrition and temperament of our experimental animals can improve compliance with two of the '3 Rs', reduction and refinement, simply by offering better control over the variance in our experimental model. The outcome is a better experimental design, on both ethical and scientific grounds.     

Investigation of in vitro measurable sperm attributes and their influence on electroejaculated bull semen with a fixed‐time artificial insemination protocol in Australian Bos indicus cattle

Increasing use of fixed‐time artificial insemination (FTAI) in beef cattle production has presented an opportunity for the use of fresh or chilled semen as an alternative to standard cryopreserved semen. The objective of this study was to examine in vitro sperm function and pregnancy rate of electroejaculated semen, chilled and stored for 48 hr, compared to conventionally cryopreserved semen with an optimized FTAI protocol in Brahman cattle. Semen from three Brahman bulls was collected, and aliquots were extended in either chilled (at 5°C) or frozen (LN₂) in a Tris‐egg yolk extender base with 2.4% or 7.0% glycerol, respectively. Semen samples were assessed 48 hr after collection or post‐thaw and warming, for sperm motility, in vitro sperm function and fertilizing ability, and used in a FTAI programme. The overall pregnancy rates was significantly different (p < .01) after FTAI with frozen (n = 173; 53.2%) and chilled semen (n = 174; 31.6%). In contrast, the in vitro sperm assessment showed that the chilled semen had significantly faster motility (p < .05), a higher proportion of progressively motile spermatozoa (p < .05), with significantly higher proportions of acrosome intact, viable spermatozoa (p < .01). This study showed that reasonable pregnancy rates in Brahman cattle can be achieved using FTAI with chilled semen collected using electroejaculation and stored for up to 48 hr. However, improvements in semen extenders are required in consideration of semen collection method to improve the longevity of sperm fertilizing ability to significantly increase FTAI output using chilled storage of bull semen.     

OSTEOCLASTS: ORGANIZATION IN CHICK EMBRYO BONE

A multinucleated endosteum was observed in the long bones of chick embryos aged 14 to 17 days. The endosteum appears to be responsible for extensive bone resorption; the bulk of the diaphyseal bone is almost completely replaced during this particular 3-day interval. Eventually, the endosteum appears to be transformed into numerous individual osteoclasts. Both the endosteum and the osteoclasts are found almost entirely on the medial surfaces of the innermost bone spicules and they seem to destroy collagen by extracellular proteolysis.