Wintersweet (Chimonanthus praecox) toxicity in four goats

CASE HISTORY: A one-year-old female goat presented with acute onset of recumbency, seizures and vocalisation approximately 5 hours after being given access to branch trimmings from a neighbour's garden. The plant from which the pruned branches came was subsequently identified as wintersweet (Chimonanthus praecox). Three other goats kept in the same paddock displayed similar clinical signs over a period of 4 hours following the initial presentation.

CLINICAL FINDINGS: All four goats were ataxic, displayed tetanic seizures and were in lateral recumbency; they had dilated pupils and were hyperaesthetic, with elevated heart and respiratory rates. After symptomatic treatment, including sedation with diazepam, one of the three goats continued to deteriorate and was subjected to euthanasia. The remaining three goats recovered over 1–14 days with nursing care and physiotherapy.

DIAGNOSIS: Toxicity due to ingestion of wintersweet, which contains the alkaloid calycanthine.

CLINICAL RELEVANCE: Calycanthine is a central nervous system toxin, causing convulsions. Wintersweet shrubs are present in many New Zealand gardens. Practitioners should be aware that the seeds and flowers, and possibly the leaves, of this plant are highly toxic with signs of toxicity including ataxia, hyperaesthesia and seizures.     

Osseous lesions resembling vaccine-site sar comas in two cats

Extract

Lytic lesions with microscopic features similar to those of vaccine-site sarcomas were diagnosed in the distal femur of two young neutered male cats, one a 20-month-old Birman and the other an 18-month-old domestic short-hair (DSH). Radiographically, there was extensive destruction of trabecular and cortical bone in the metaphysis and/or epiphysis of the distal femur. The DSH cat also had angular deformity of the distal femur due to asymmetrical involvement of the physis. Histologically, the lesions in both cats consisted of dense, interwoven bundles of fibrous connective tissue, amongst which there were variable numbers of plump malignant mesenchymal cells, often with very large, hyperchromatic nuclei and irregularly shaped nucleoli. Several focal aggregates of small lymphocytes were present in both tumours. Although neither cat had apparently been vaccinated in the hindlimb it is possible that the tumours had been triggered by injection of some other irritant material.     

Expression of Genes in the Canine Pre‐implantation Uterus and Embryo: Implications for an Active Role of the Embryo Before and During Invasion

The aim of the present study was to assess genes expressed in maternal uterine tissue and pre‐implantation embryos which are presumably involved in maternal recognition and establishment of canine pregnancy. For this purpose, 10 pregnant bitches were ovariohysterectomized between days 10 and 12 after mating. Four non‐pregnant bitches served as controls. Early pregnancy was verified by flushing the uterine horns with PBS solution. The collected embryos (n = 60) were stored deep‐frozen (?80°C). Uterine tissue was excised, snaps frozen in liquid nitrogen and homogenized using TRI Reagent. All embryos from one litter were thawed together and also homogenized in TRI Reagent. RT‐PCR was performed to prove mRNA expression of progesterone receptor, key enzymes of the prostaglandin synthesis pathway, selected growth factors, cytokines, immune cell receptors, major histocompatibility complex (MHC) and matrix‐metalloproteinases (MMP). Only pregnant uteri revealed the presence of mRNA for interferon (IFN)‐γ, IL‐4 and CD‐8, which resembles the milieu in humans and other mammalians. Similarly, in day 10 embryos, mRNA for transforming growth factor‐β, insulin‐like growth factor‐1,‐2, hepatocyte growth factor, leukaemia inhibitor factor, tumour necrosis factor‐α, interleukin‐1β,‐6,‐8, cyclooxygenase‐2, CD4⁺ cells, and MMP‐2 and ‐9 were detected, but not MHC‐I or ‐II. We therefore suppose that the canine embryo, like its human counterpart, actively initiates measures to prevent attacks from the maternal immune system to prepare its own adhesion, nidation, growth and further development.     

Efficiency of uterine fluid cytology in the diagnosis of subclinical endometritis in the water buffalo (Bubalus bubalis)

This study compared endometrial cytology vis‐a‐vis uterine fluid cytology for assessment of uterine health in clinically normal and subclinical endometritis (SE)‐affected buffaloes. Uterine fluid samples and endometrial samples were collected from the buffaloes (n = 38) at oestrus using blue sheath and cytobrush, respectively. The smears were stained with Field stain for 3 minutes, and a minimum of 400 cells were counted in each smear for determination of the percentage of polymorphonuclear (PMN) leucocyte. The incidence of subclinical endometritis, based on the cytobrush cytology, was 23.08%. The correlation between cytobrush cytology with uterine fluid cytology was positive and significant (r = .37; p = .02). The ratio of PMN leucocyte in cytobrush cytology to uterine fluid cytology was 1:2.4. ROC analysis revealed that the threshold value of 6.16% PMN leucocyte in uterine fluid cytology showed a diagnostic sensitivity and specificity of 100% in differentiating normal from SE‐affected buffaloes. In conclusion, collection of uterine fluid was easier compared to collection of endometrial samples using cytobrush and the percentage of PMN leucocyte in uterine fluid cytology can be used as a tool for diagnosis of subclinical endometritis in buffaloes.     

Photorefractive materials for nonvolatile volume holographic data storage

Optically gated recording and nonvolatile readout in a digital volume holographic data storage system that uses a pair of mutually incoherent light sources during recording and only one for readout were demonstrated recently. This approach used stoichiometric lithium niobate, which after post-growth processing gave rise to an at least two orders of magnitude improvement in sensitivity over the best materials reported previously. It is also shown that by adding certain dopants (iron and manganese) to near-stoichiometric lithium niobate, the dark storage time and gating efficiency can be increased compared with previous work. The underlying physical mechanisms of gated recording and the effectiveness of the gating process responsible for this manifold improved performance are discussed, and bipolarons and small polarons are identified as the responsible photorefractive species.     

Evidence for new sources of NOX in the lower atmosphere

Laboratory studies show that the reaction of short-lived O2(B3Sigmau) molecules (lifetime approximately 10 picoseconds) with N2 and the photodissociation of the N2:O2 dimer produce NOx in the stratosphere at a rate comparable to the oxidation of N2O by O(1D). This finding implies the existence of unidentified NOX sinks in the stratosphere. The NO2 observed in this experiment is isotopically heavy with a large 15N/14N enhancement. However, photodissociation of this NO2 unexpectedly produced NO molecules with a low 15N/14N ratio. The diurnal odd-nitrogen cycle in the stratosphere will be marked by a complex isotope signature that will be imprinted on the halogen and HOX catalytic cycles.     

The 18O/16O and 17O/16O ratios in atmospheric nitrous oxide: A mass-independent anomaly

Measurements of the oxygen isotope ratios (18O/16O and 17O/16O) in atmospheric nitrous oxide (N2O) from La Jolla, Pasadena, and the White Mountain Research Station (elevation, 3801 meters) in California and the White Sands Missile Range in New Mexico show that N2O has a mass-independent composition. These data suggest the presence of a previously undefined atmospheric process. The La Jolla samples can be explained by a mixing between an atmospherically derived source of mass-independent N2O and biologically derived mass-dependent N2O. Possible origins of the mass-independent anomaly in N2O are discussed.     

The effect of selenium supplementation on immunity, and the establishment of an experimental Haemonchus contortus infection, in weaner Merino sheep fed a low selenium diet

SUMMARY: Immunity in 12 weaner Merino sheep fed a low selenium (Se) diet (low Se sheep) was compared with that in 10 matching sheep fed the same diet but each given an intraruminal Se pellet (high Se sheep), while the sheep were housed in individual, sheltered pens. All sheep were challenged with killed Brucella abortus cells (days 0 and 28), rabbit red blood cells (days 0, 7 and 28) and corynebaclerium pseudotuberculosis toxoid (days 0 and 28), and serum antibody titres were measured weekly for 8 weeks from day 0. The sheep were then experimentally infected with Haemonchus conforfus, and slaughtered 8 weeks later. The mean antibody titre to B. abortus, measured by 4 different tests, was significantly higher in the high Se sheep on occasions during the primary immune response phase (Rose Bengal test - day 21 (p < 0.05), day 28 (p < 0.025); complement fixation - day 7 (p < 0.05); enzyme-llnked immunosorbent assay - day 14 (p < 0.01); serum agglutination - no differences), but not during the secondary phase. The mean antibody titre to rabbit red blood cells, measured by haemagglutination test, was marginally higher in the high Se sheep on day 49 (p = 0.049). The mean antibody titre to C. pseudotuberculois, measured by enzyme-linked immunosorbent assay, was not significantly different between the groups at any time during the trial. In addition, the mean invitro responsiveness of peripheral blood lymphocytes to stimulation with phytohaemagglutinin in the high Se sheep was significantly greater than that in 10 sheep from the low Se group on day 22 (p < 0.01), but not day 50. However, there were no significant differences in the mean number of sheep in which the infection with H. contortus established, time to first shedding of eggs in faeces, abomasal worm burdens at necropsy, or inflammatory response in the abomasal mucosa in the sheep in each group. The results showed that the low Se sheep produced strong overall immune responses that were largely comparable to those in the high Se sheep.     

Real-time quantitative PCR assays for quantification of L1781 ACCase inhibitor resistance allele in leaf and seed pools of Lolium populations

The I1781L amino acid substitution in the target ACCase enzyme causes broad resistance to ACCase inhibitor herbicides in several monocotyledenous weeds of agronomic importance. This mutation results from a substitution of an adenine (A) residue by either a thymine (T) or cytosine (C) at position 5341 in Alopecurus myosuroides Huds and at an equivalent position in Lolium species, Avena fatua L. and Setaria viridis (L.) Beauv. Two different procedures, the PCR-based allele-specific assay (ASA) and the derived cleaved amplified polymorphic sequence (dCAPS) method, have previously been described for detecting this mutation. These methods are, however, only amenable to low sample throughput and are used in the analysis of single plants. Here, an alternative high-throughput ARMS/Scorpion real-time quantitative PCR (Q-PCR) method for measuring levels of the I1781L mutation in pools of leaf and seed samples of Lolium populations is presented. The limit of detection for C and T mutant alleles in a background of wild-type A is 0.02 and 0.0003% respectively. In this study, DNA from batches of 24 leaf segments measuring 0.5 cm from different plants or 1000 seeds could be conveniently extracted and accurately analysed. As part of assay validation, the comparative analysis of five geographically distinct Lolium populations with dCAPS and Q-PCR procedures demonstrated the accuracy of the latter method, and the three possible II1781, IL1781 and LL1781 ACCase genotypes being distributed as predicted by the Hardy-Weinberg principle. Given the dominance of the L1781 over the I1781 allele at recommended field rates for most ACCase inhibitors, the frequency of herbicide survivors in the field owing only to the presence of the I1781L mutation is thus predicted to be 2pq + q(2), where p and q are the frequencies of the I1781 and L1781 alleles as determined by Q-PCR. The Q-PCR assay established allows detection of very low levels of the L1781 ACCase mutation before resistance would normally be discernible in the field. Therefore, it offers the opportunity to tackle resistance at its very onset, potentially avoiding implementation of complicated and often costly weed management practices.