Osteopetrosis in a neonatal donkey

Osteopetrosis is a rare disorder characterised by a defect in osteoclastic bone resorption. This report describes osteopetrosis in a neonatal donkey that suffered a displaced tibial fracture. Radiographic examination identified generalised reduction in medullary cavity size, thickened mid‐diaphyseal cortices and conical metaphyseal bone extending toward the mid‐diaphysis of long bones. Postmortem examination identified additional fractures and brittle bones. Histologically, osteoclasts were absent in multiple bone sections. Diaphyseal cortices consisted of concentric bone lamellae with marrow tissue infiltration. Large wedges of secondary spongiosa extended from the metaphyseal growth plate. Clinical and histopathological features were similar to an osteoclast‐deficient, autosomal recessive form of osteopetrosis in humans.     

Endometrial Explant Culture to Study the Response of Equine Endometrium to Insemination

Mating‐induced endometritis (MIE) is ubiquitous in the horse after natural mating and artificial insemination with frozen/thawed semen causing the most aggressive response. The majority of mares eliminate MIE 24–48 h after insemination. An endometrial explant culture was tested as a potential in vitro exemplar for sperm‐induced MIE. Endometrial prostaglandin F_2α (PGF_2α) secretion and expression of interleukin‐8 (IL‐8) were used as markers of inflammation. Endometrial explants were cultured from uteri collected from follicular phase mares. Explants were challenged with 1 or 10 × 10⁶ sperm/ml frozen/thawed semen, chilled semen, washed sperm or seminal plasma. Medium was collected 24 and 72 h after challenge and assayed for PGF_2α by radioimmunoassay. Treatment of endometrial explants with frozen/thawed, chilled semen or washed sperm did not change the secretion of PGF_2α compared with untreated controls. However, 24 h after challenge cultured explants expressed IL‐8. The in vitro endometrial explant system did not represent the in vivo response to semen when PGF_2α was used as a marker of inflammation, yet the use of gene expression as an inflammatory marker warrants further investigation.     

施用活性硅降低重金属移动性的研究

该研究通过一系列的土柱实验研究土壤中硅和重金属的反应机制。土柱实验在可溶性镉、铜、镍和铅酸盐的情况下,用各种活性硅（硅藻土,沸石,无定形二氧化硅,浓缩单硅酸）处理灰森林土。所有富硅物质都用电子显微镜测试分析过。富硅物质对土壤中重金属的钝化试验结果表明：硅藻土和浓缩单硅酸比沸石和无定形二氧化硅更能降低重金属的移动性。重金属移动性的降低是由土壤溶液中单硅酸和重金属的反应,以及富硅物质表面对重金属的吸附实现的。重金属在土壤中移动的强度与自身种类有关。施用富硅物质可明显降低镉和镍的移动性,对铜和铅的效果不明显。     

Urinary catheterisation of female dogs: a comparison between three techniques for catheter placement

The objective of this study was to describe a new technique for urinary catheterisation of female dogs using a novel catheterisation device (NCD) and to compare the time taken to place a catheter using this technique with traditional techniques. A secondary objective was to survey participants on which of the techniques they preferred. Female canine cadavers of varying sizes were utilised and veterinary students who had not previously placed a urinary catheter were enrolled. Each participant performed three catheterisation techniques, Visual with speculum (SPEC), Blind Palpation (BP) and catheterisation with NCD on three sizes of dog. Time required using each technique was compared using Kaplan–Meier plots and mixed models Cox Proportional Hazards regression. Median times to catheterisation were 300 s (IQR 261–417 s) with the SPEC method, 420 s (IQR 253–545 s) with the NCD method and 725 s (574–1032s) with the BP method. Both SPEC and NCD methods were significantly faster compared to the BP method, with Hazard Ratios of 3.66 (95% CI 1.94–6.91, P < 0.001) and 3.57 (95% CI 1.87–6.81, P < 0.001), respectively. Six of nine participants found the NCD the easiest technique, 5/9 of the participants found the palpation technique most difficult and 4/9 found the speculum technique most difficult. BP appears to be the technique of least preference and increased time requirement. The novel urinary catheterisation device may provide a simpler method of visualisation of the urethral papilla and may provide a more sterile way of placing the catheter, although further investigation is needed to confirm this.     

Recent advances in photoelectric aerosol measurements

After recalling briefly the optical properties of aerosols, we describe the principle and the working conditions of photoelectric apparatus for aerosol measurements. Two size distribution analyzers are presented: the first one is based on a classical detection principle, the minimum detectable radius being 0.2 µm, and the maximum concentration 3 × 10⁴ particles cm^?3; the second one is based on a photon counting technique, with which particles of radius between 0.03 and 0.2 µm can be measured at maximum number concentration of 2 × 10⁶ particles cm^?3. We describe then two Condensation Nuclei Counters (CNC) with continuous flux; in these types of apparatus, the vapor of a liquid is condensed on Aitken nuclei using a Peltier effect device. They are thereby rendered visible and counted using a classical photoelectric method. One apparatus works under normal conditions of pressure and temperature, while the other one works under stratospheric conditions, i.e., at low pressure and temperature. The concentration range is still between 10 and 10⁶ nuclei cm^?3 and the minimum concentration is 0.1 particle cm^?3 in the case of the stratospheric counter. The four devices work on individual particles; their characteristics are compared to those of commercially available apparatus and their advantages discussed.     

Slurry-application implement tine modification of soil hydraulic properties under different soil water content conditions for silt–clay loam soils

Tillage action associated with liquid slurry application systems/management practices can modify soil infiltration properties. The degree or nature of such modification will depend largely on the type of tillage implement used, and the soil conditions at time of tillage activity. The specific objective of this study is to evaluate differences in soil infiltration properties, as measured using pressure infiltrometers and Guelph permeameters, resulting from the immediate tine action of two commonly used slurry application tillage implements (Kongskilde Vibro-Flex (S-tine) and the AerWay SSD (rolling aerator-type tine)) over a variety of silt–clay loam soil water content conditions. The results indicated that there were consistent negative correlations between field saturated hydraulic conductivity and soil water content for all tine-disturbed and undisturbed soil treatments. For Kongskilde, field-saturated hydraulic conductivity was, on average, lower in tine-influenced furrow bottoms, relative to those measured in undisturbed conditions at similar depths for most water content conditions. Generally, the Kongskilde tine-action reduced macropore-based infiltration in the bottom of the furrow for most soil conditions, albeit, this effect was most pronounced at the higher soil water contents. For AerWay, the tine-disturbed soils had generally higher field saturated hydraulic conductivities than undisturbed soil treatments over the observed water content range. This effect was manifested to a greater degree at higher, relative to lower observed water contents.     

Importance of oil overlay for production of porcine embryos in vitro

Technologies to edit the zygote genome have revolutionized biomedical research not only for the creation of animal models for the study of human disease but also for the generation of functional human cells and tissues through interspecies blastocyst complementation technology. The pig is the ideal species for these purposes due to its great similarity in anatomy and physiology to humans. Emerging biotechnologies require the use of oocytes and/or embryos of good quality, which might be obtained using in vitro production (IVP) techniques. However, the current porcine embryo IVP systems are still suboptimal and result in low monospermic fertilization and blastocyst formation rates and poor embryo quality. During recent years, intensive investigations have been performed to evaluate the influence of specific compounds on gametes and embryos and to avoid the use of undefined supplements (serum and serum derivate) in the incubation media. However, little consideration has been given to the use of the mineral oil (MO) to overlay incubation droplets, which, albeit being a routine component of the IVP systems, is a totally undefined and thus problematic product for the safety of gametes and embryos. In this review, we provide an overview on the advantages and disadvantages of using MO to cover the incubation media. We also review one important concern in IVP laboratories: the use of oils containing undetected contamination. Finally, we discuss the effects of different types of oils on the in vitro embryo production outcomes and the transfer of compounds from oil into the culture media.     

Photosynthetic responses and N allocation in Douglas-fir needles following a brief pulse of nutrients

The temporal distribution of soil nutrients is heterogeneous, and thus the uptake, storage and later remobilization of brief nutrient pulses may be critical for growth in nutrient-limited habitats. We investigated the response of photosynthesis and the major nitrogen (N) fractions in needles of 2-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings to a 15-day nutrient pulse (containing 250 ppm N). The nutrient pulse (N pulse) was imposed in late July, toward the end of the seedlings' third growing season, and subsequent changes in photosynthesis and needle N fractions were examined over the following 3 months. Needles are sites of photosynthesis and putative storage organs. Thus we tested two hypotheses: (1) N from the N pulse is quickly synthesized from soluble non-protein N into soluble proteins, especially Rubisco, and (2) the N pulse increases photosynthetic rates and thus growth. We also examined an alternative hypothesis that Rubisco functions also as a storage protein, in which case we would predict increases in amount of Rubisco in response to the N pulse without concomitant increases in photosynthesis. Soluble non-protein N was the most dynamic N pool and may have constituted a temporary storage reservoir; however, the quantitative significance of soluble non-protein N is questionable because this pool was at most only 7% of total N. Concentrations of Rubisco were unaffected by the N-pulse treatment and there was little evidence that Rubisco served as a storage protein. Nutrient-pulse seedlings added twice as much dry mass as controls during the 3 months post-treatment (Warren et al. 2003a). Over the same period, the maximum rate of light-saturated photosynthesis (A(max)) declined to low rates in control seedlings, whereas A(max) increased in N-pulse seedlings. Nevertheless, treatment and temporal trends in N and Rubisco content per unit area were poorly related to A(max), and it seems likely that photosynthesis was limited by additional factors, perhaps thylakoid proteins or an inadequate supply of other nutrients.     

Therapeutic Ultrasound as a Potential Male Dog Contraceptive: Determination of the Most Effective Application Protocol

Ultrasound is one of the most promising forms of non‐invasive contraception and has been studied in several animal models. The objective of the current investigation was to determine the most practical and effective application protocol for dog sterilization. A total of 100 dogs were divided into five equal groups. Group A received 5‐min applications three times performed at 48‐hr intervals and covering the entire testicular area at frequency of 1 MHz; Group B received 5‐min applications three times performed at 48‐hr intervals over the dorso‐cranial area of the testis at frequency of 3 MHz; Group C received three sequential 5‐min applications (at 5‐min intervals between applications) covering the entire testicular area at frequency of 1 MHz; Group D received 15‐min applications two times performed at 48‐hr intervals and covering the entire testicular area at frequency of 1 MHz. The experimental groups' ultrasound had an intensity of 1.5W/cm². The Control Group had the same procedure as Group A, but with the transducer switched‐off. Dogs were surgically castrated 40 days following the treatment for histological examination. Azoospermia, testicular volume reduction and apparently irreversible testicular damage were achieved by Group A. No effects were noticed in the other groups. Testosterone levels remained within physiological range with all application protocols. A regimen of three applications of ultrasound at 1 MHz, and 1.5 W/cm², lasting 5 min with an interval of 48 h was effective as permanent sterilization in the dog without hormonal impact.