Management of equine skull fractures using fixation with polydioxanone sutures

Ten horses presented with severe distortion of the facial contour, crepitus on palpation and mild to moderate epistaxis. Individual horses also showed ocular damage, ptosis, severe dyspnoea and movement of the facial bones concurrent with respiration. The fracture fragments were exposed using a large curvilinear incision and elevated using a retractor, periosteal elevator, chisel or Steinmann pin. The fracture fragments were unstable following reduction and fixation was necessary. Stabilisation was achieved with polydioxanone sutures placed through holes drilled in opposing sides of the fracture lines. Polydioxanone sutures provided good stability and had better handling properties than wire. There was good apposition of fracture edges and minimal complications. Use of polydioxanone sutures can also avoid the expense and complexity of plate fixation in selected cases, and should be considered as an alternative to fixation with stainless steel wire in any facial fracture that adjoins stable bone.     

Effect of Dimethyl Sulfoxide on Cell Cycle Synchronization of Goldfish Caudal Fin Derived Fibroblasts Cells

Several studies have previously been conducted regarding cell cycle synchronization in mammalian somatic cells. However, limited work has been performed on the control of cell cycle stages in the somatic cells of fish. The aim of this study was to determine the cell cycle arresting effects of several dimethyl sulfoxide (DMSO) concentrations for different times on different cell cycle stages of goldfish caudal fin‐derived fibroblasts. Results demonstrated that the cycling cells or control group (68.29%) yields significantly higher (p < 0.05) arrest in G0/G1 phase compared with the group treated for 24 h with different concentrations (0.5%, 1.0% or 1.5%) of DMSO (64.88%, 65.70%, 64.22% respectively). The cell cycle synchronization in the treatment of cells with 1.0% DMSO at 48 h (81.14%) was significantly higher than that in the groups treated for 24 h (76.82%) and the control group (77.90%). Observations showed that treatment of DMSO resulted in an increase in the proportion of cells at G0/G1 phase for 48 h of culture. However, high levels of apoptotic cells can be detected after 48 h of culture treated with 1% concentration of DMSO.     

Individual and socially learned preferences for biserrula (Biserrula pelecinus L.) in sheep

This study examined how sheep develop a learned aversion to the annual legume biserrula (Biserrula pelecinus L.). Merino sheep were grazed on paddocks sown with either (i) biserrula, (ii) biserrula + ryegrass (Lolium rigidum Gaud.), (iii) crimson clover (Trifolium incarnatum L.), (iv) crimson clover + ryegrass or (v) ryegrass, for 4 weeks. Relative preference (Chesson–Manly selection index) was determined by offering randomly ordered monoculture plots of the three forage species. The groups of sheep were then combined into a single group and grazed a paddock containing a monoculture sward of each plant type for 5 d. Relative preference of sheep was tested again after the completion of the combined grazing. The experiment was repeated at three stages of plant phenology: vegetative, reproductive and senesced. Relative preference for biserrula was lower in sheep that had grazed the paddock sown with only biserrula compared with sheep that grazed a combination of biserrula + ryegrass, at both the vegetative (α; −0·11 vs. 0·32) and reproductive (α; 0·18 vs. 0·63) stages. At each stage of phenology, when groups were combined and grazed together, preference for biserrula became uniform. This supported the hypothesis that sheep develop an aversion to biserrula when they graze a pasture containing biserrula. However, we concluded that the familiarity of sheep with biserrula did not result in low relative preference; rather, the aversion was more likely a response to the high proportion of this plant in their diet. Social facilitation may have enabled sheep to overcome rapidly the food aversion.     

Effect of testicular tissue lysate on developmental competence of porcine oocytes matured and fertilized in vitro

The objective of the present study was to investigate the effect of testicular tissue lysate (TTL) on developmental competence of germinal vesicle (GV) stage porcine oocytes. Two types of TTL were prepared through repeated freeze–thaw in liquid nitrogen, one from whole testicular tissue (wTTL) and other from either of four different sections of testes, namely just beneath the tunica albuginea (TA), from the transitional area between the seminiferous cord/tubules and the mediastinum testis (TR) and from the intermediate area (parenchymal tissue origin) and CE (cauda epididymis origin). The whole or section‐wise TTL treatments were given for 44 hr during in vitro maturation (IVM). Oocyte maturation was done in either of the two media, namely defined (high‐performance basic medium for porcine oocyte maturation, commercially available) and serum containing (TCM199). After maturation, oocytes were co‐incubated with fresh spermatozoa for 6 hr and then transferred to embryo culture media. Treatment of GV stage oocytes with wTTL (1 mg/ml) increased the cleavage and morula percentage rate (69.23 ± 6.23 and 48.15 ± 6.77, respectively) than that of their control (58.33 ± 8.08 and 32.54 ± 5.53, respectively) in defined media, and in serum‐containing media, cleavage and morula percentage rate were almost equal in both treatment (54.56 ± 7.79 and 34.70 ± 6.78, respectively) and control (59.52 ± 8.21 and 38.52 ± 6.54, respectively). However, effect of wTTL was not significant. In case of section‐wise TTL supplements, TR section significantly (p < .01) improved cleavage and morula rate (58.43 ± 7.98 and 36.14 ± 6.89, respectively) followed by TA. In conclusion, present study indicates that IVM, in vitro fertilization and in vitro culture of embryo are improved in the presence of TTL, particularly its TR section. Further study is expected to reveal the principal components of TTL which may prove useful for IVM.     

Shearing during pregnancy--review of a policy to increase birthweight and survival of lambs in New Zealand pastoral farming systems

Over the past decade, lambing percentages have risen in conjunction with a rise in the percentage of multiple lambs born. Multiple-born lambs are smaller than their singleton counterparts and are particularly susceptible to starvation-exposure. Any technique that can increase the birthweight or thermoregulatory capability, or both, of otherwise lightweight lambs has the potential to substantially increase survival of multiple-born lambs. In the United Kingdom under housed conditions, shearing during pregnancy has been shown to increase both the birthweight and thermoregulatory capability of newborn lambs. However, shearing during pregnancy under pastoral conditions has failed to consistently affect the newborn lamb's thermoregulatory capability. In contrast, under New Zealand's pastoral conditions shearing during pregnancy has been found to increase birthweight, but results have been inconsistent in both magnitude and birth-rank specificity. Increase in feed intake by the dam, types of shearing comb used and changes in gestation length do not explain the variation observed. When studies involving shearing during pregnancy are collated it becomes apparent that there are two criteria that must be met to achieve a birthweight response. Firstly, the dam must have the potential to respond and secondly, the dam must have the means to respond. Any increase in lamb survival through shearing during pregnancy would be predominantly through an increase in birthweight of otherwise lightweight lambs. However, in the few studies conducted to date, an increase in birthweight has not resulted in a statistically significant increase in survival. For an increase in birthweight to have a positive effect on lamb survival, lambs must be otherwise destined to be born within a birthweight range in which survival rate is below optimum (<4.0 kg), and the increase in birthweight observed must move a significant proportion of otherwise lightweight lambs into a higher range of survival rate.     

Signalling Events and Associated Pathways Related to the Mammalian Sperm Capacitation

Capacitation is a biological phenomenon occurring prior to fertilization and is a multiple event process. Many physiological and biochemical changes takes place during the process; these changes are related to lipid composition of membrane, intracellular modulation of ion concentration, protein phosphorylation, sperm movement and membrane permeability. These events occur when the sperm is exposed to the new environment of ion concentration in the female reproductive tract. Ions such as bicarbonate and calcium facilitate capacitation by activating adenylyl cyclase, thus initiating protein kinase A (PKA) signalling cascade. Extracellular‐regulated kinase pathway is activated by ligand binding to the membrane receptors and intracellular activation by reactive oxygen species (ROS). Activation of these pathways leads to the phosphorylation of different proteins, which is associated with events such as capacitation, hyperactivation and acrosome reaction that are essential for successful fertilization. Extensive studies were carried out on protein phosphorylation in relation to capacitation, but its role still remains ambiguous.