Establishment and characterisation of ovine blood monocyte-derived cell lines

Studies of the important functions in host defense assured by macrophages, both as functional elements and as potential targets for intracellular pathogens, are often inhibited by the lack of a source of large numbers of uniform, well-characterised cells. To address this lack for ovine studies, we have established cell lines from spontaneously-proliferating adherent mononuclear cells from sheep blood. Eight such lines which have been continuously cultured for over 400 passages have phagocytic activities and cytochemical characteristics indicating that they retain the nature of mononuclear phagocytes. They display typical functional membrane proteins such as CD14, Fc receptors and MHC class II. Such cells can facilitate in vitro studies of pathogen-monocyte interactions and can furnish copious amounts of cells for transfer experiments.     

Rectal prolapse associated with a healed pelvic fracture in a pregnant free-ranging African black rhinoceros (Diceros bicornis). Part 2: surgery and necropsy

The oedematous and traumatised protruding section of the rectal tissue of an adult free-ranging female African black rhinoceros (Diceros bicornis) was surgically amputated. Immediately before completion of surgery, the rhinoceros died of anaesthetic-related cardiac arrest. At necropsy a deformed pelvis and sacrum associated with a healed fracture of the left ileal wing were noted. New bone formation in and around the left ventral sacral foramina may have resulted in neuropathy of particularly the 3rd and 4th left ventral sacral nerves, which (in the horse) supply the majority of the nerve fibres innervating the caudal rectum and anus. The cause of the injury is not known, although back injuries, presumably sustained during mating by bulls, have been recorded in white rhinoceros. An encounter with elephants could also have been responsible for the injury in this case.     

The effect of frog pressure and downward vertical load on hoof wall weight-bearing and third phalanx displacement in the horse--an in vitro study

A shoe was designed to combine the advantages of a reverse shoe and an adjustable heart bar shoe in the treatment of chronic laminitis. This reverse even frog pressure (REFP) shoe applies pressure uniformly over a large area of the frog solar surface. Pressure is applied vertically upward parallel to the solar surface of the frog and can be increased or decreased as required. Five clinically healthy horses were humanely euthanased and their dismembered forelimbs used in an in vitro study. Frog pressure was measured by strain gauges applied to the ground surface of the carrying tab portion of the shoe. A linear variable distance transducer (LVDT) was inserted into a hole drilled in the dorsal hoof wall. The LVDT measured movement of the third phalanx (P3) in a dorsopalmar plane relative to the dorsal hoof wall. The vertical component of hoof wall compression was measured by means of unidirectional strain gauges attached to the toe, quarter and heel of the medial hoof wall of each specimen. The entire limb was mounted vertically in a tensile testing machine and submitted to vertical downward compressive forces of 0 to 2,500 N at a rate of 5 cm/minute. The effects of increasing frog pressure on hoof wall weight-bearing and third phalanx movement within the hoof were determined. Each specimen was tested with the shoe under the following conditions: zero frog pressure; frog pressure used to treat clinical cases of chronic laminitis (7 N-cm); frog pressure clinically painful to the horse as determined prior to euthanasia; frog pressure just alleviating this pain. The specimens were also tested after shoe removal. Total weight-bearing on the hoof wall at zero frog pressure was used as the basis for comparison. Pain-causing and pain-alleviating frog pressures decreased total weight-bearing on the hoof wall (P < 0.05). Frog pressure of 7 N-cm had no statistically significant effect on hoof wall weight-bearing although there was a trend for it to decrease as load increased. Before loading, the pain-causing and pain-alleviating frog pressures resulted in a palmar movement of P3 relative to the dorsal hoof wall compared to the position of P3 at zero frog pressure (P < 0.05). This difference remained statistically significant up to 1300 N load. At higher loads, the position of P3 did not differ significantly for the different frog pressures applied. It is concluded that increased frogpressure using the REFP shoe decreases total hoof wall weight-bearing and causes palmar movement of P3 at low weight-bearing loads. Without a shoe the toe and quarter hoof wall compression remained more constant and less in magnitude, than with a shoe.     

Pacific-Ciguatoxin-2 and Brevetoxin-1 Induce the Sensitization of Sensory Receptors Mediating Pain and Pruritus in Sensory Neurons

Ciguatera fish poisoning (CFP) and neurotoxic shellfish poisoning syndromes are induced by the consumption of seafood contaminated by ciguatoxins and brevetoxins. Both toxins cause sensory symptoms such as paresthesia, cold dysesthesia and painful disorders. An intense pruritus, which may become chronic, occurs also in CFP. No curative treatment is available and the pathophysiology is not fully elucidated. Here we conducted single-cell calcium video-imaging experiments in sensory neurons from newborn rats to study in vitro the ability of Pacific-ciguatoxin-2 (P-CTX-2) and brevetoxin-1 (PbTx-1) to sensitize receptors and ion channels, (i.e., to increase the percentage of responding cells and/or the response amplitude to their pharmacological agonists). In addition, we studied the neurotrophin release in sensory neurons co-cultured with keratinocytes after exposure to P-CTX-2. Our results show that P-CTX-2 induced the sensitization of TRPA1, TRPV4, PAR2, MrgprC, MrgprA and TTX-r NaV channels in sensory neurons. P-CTX-2 increased the release of nerve growth factor and brain-derived neurotrophic factor in the co-culture supernatant, suggesting that those neurotrophins could contribute to the sensitization of the aforementioned receptors and channels. Our results suggest the potential role of sensitization of sensory receptors/ion channels in the induction or persistence of sensory disturbances in CFP syndrome.     

Experimental micromechanical characterisation of wood cell walls

The properties of wood and wood-based materials are strongly dependent on the properties of the fibres, that is, the cell wall properties. It is thus highly important to be able to mechanically characterise cell walls in order to understand structure–property relationships. This article gives a brief overview of the state of the art in experimental techniques to characterise the mechanical properties of wood at both the level of the single cell and that of the cell wall. Challenges, opportunities, drawbacks and limitations of single fibre tensile tests and nanoindentation are discussed with respect to the wood material properties.     

Bordetella bronchiseptica experimental model development in pigs and efficacy evaluation of a single intramuscular injection of gamithromycin (Zactran® for Swine) against Bordetella bronchiseptica-associated respiratory disease in experimentally infected piglets

In the Bordetella bronchiseptica infection model development study, twenty-eight piglets were inoculated with B. bronchiseptica strain of either canine (10⁹ CFU/ml) or swine (10⁸ and 10⁹ CFU/ml) origin; swine origin strain at 10⁹ CFU/ml was chosen for the efficacy assessment study due to higher incidence and severity of gross and histopathological lesions compared with other strains. To assess efficacy of gamithromycin against B. bronchiseptica, forty piglets were experimentally inoculated on Day 0 and clinical signs were scored as per severity. Animals were then treated either with gamithromycin or saline on Day 3. The Global Clinical Scores in gamithromycin-treated group were consistently lower than the saline-treated control group from Day 4 onwards and were 0 and 40 in the gamithromycin-treated and saline-treated control groups, respectively, on Day 6. Severity and frequency of gross and histopathological observations were significantly lower in gamithromycin-treated animals compared with saline-treated controls. The efficacy of Zactran® for Swine at the label dose for the treatment of B. bronchiseptica–associated respiratory disease was demonstrated based on the faster reduction in clinical signs as early as 1 day post-gamithromycin treatment and based on the significant difference in the severity of macroscopic and microscopic lung lesions 10 days post-gamithromycin treatment.     

Cytological description of testicular cell populations in sexually mature cats with normal spermatogenesis

In cats, assessment of the testicular function is mainly based on sperm evaluation. Whatever the technique used, the volume of collected sperm is often small, which may lead to technical difficulties to achieve the semen evaluation in routine practice. Fine-needle aspiration (FNA) biopsy of the testicular parenchyma is one of the other methods used to assess testicular function. The aim of this study was to explore the relevance of FNA in the assessment of testicular cells in sexually mature cats. Eighteen cats over one year of age were recruited among animals presented for surgical neutering. Semen was collected by electroejaculation before it was evaluated. FNA biopsies of the testicles were taken using a 21-gauge needle. After castration, histological analysis of the testes was performed. Semen evaluation and histological analysis showed no anomalies, which confirmed normal spermatogenesis in all the cats and allowed a proper interpretation of the cytological findings. The cells identified through cytological examination were spermatogonia (1.99 ± 0.17%), primary spermatocytes (10.49 ± 0.74%), round spermatids (34.80 ± 1.57%), elongated spermatids (23.59 ± 2.02%), spermatozoa (21.56 ± 1.86%), Sertoli cells (7.53 ± 1.23%) and Leydig cells (0.04 ± 0.03%). However, spermatocytes II were not identified. This is due to the low proportions of these cells, related to their very short lifespan. Likewise, the very low number of Leydig cells observed is probably due to the damage caused during the aspiration stage. This study showed that fine-needle aspiration is an efficient method to describe cytologically normal testicular populations, a cornerstone for future research aimed to study abnormal spermatogenesis and to correlate it to cytological proportion of germ cells.     

Contribution of cacao agroforestry versus mono-cropping systems for enhanced sustainability. A review with a focus on yield

The demand for cocoa has increased over the past years following the growth of cocoa-based products linked to the rise in living standard in highly populated countries. Cacao industry is therefore currently facing the dilemma of producing more cacao while ensuring its sustainability. Cacao monocrops and agroforestry systems (AFS) are two contrasting ways to produce cocoa, yet their impact on yields, contribution to farmer livelihood, cocoa quality remains understudied. Therefore, we reviewed existing literature comparing (1) monocrop cacao farming systems with (2) simple or (3) complex AFS. We found 19 comparisons of the cocoa yields in monocrops and simple AFS and 20 comparisons of monocrop and complex AFS. Three main research findings derive from this work. First, in about one third of cases, cacao trees yield more (or equally) in AFS than in monocrops. However, when considering only simple AFS, cacao trees yield more or equal to cacao monocrop in 52% of the cases. Second, cocoa AFS yields an average of 14% less than cacao monocrop. Yet, on average simple AFS yielded 2% less than cacao monocrops. Finally, there are too little elements to draw conclusions about the nexus between cocoa quality and cacao tree cultivation system.

     

Optical pumping and vibrational cooling of molecules

The methods producing cold molecules from cold atoms tend to leave molecular ensembles with substantial residual internal energy. For instance, cesium molecules initially formed via photoassociation of cold cesium atoms are in several vibrational levels nu of the electronic ground state. We applied a broadband femtosecond laser that redistributes the vibrational population in the ground state via a few electronic excitation/spontaneous emission cycles. The laser pulses are shaped to remove the excitation frequency band of the nu = 0 level, preventing re-excitation from that state. We observed a fast and efficient accumulation ( approximately 70% of the initially detected molecules) in the lowest vibrational level, nu = 0, of the singlet electronic state. The validity of this incoherent depopulation pumping method is very general and opens exciting prospects for laser cooling and manipulation of molecules.