Optimization of an ovine antibody-secreting cell assay for detection of antigen-specific immunoglobulin production in peripheral blood leukocytes

Enumeration of antibody-secreting cells in peripheral blood by enzyme-linked immunospot (ELISPOT) has been used in human studies to detect antigen-specific antibody production at mucosal tissue sites. An alternative assay for detecting and quantitating antigen-specific antibody responses involves culturing circulating peripheral blood antibody-secreting cells and quantitating specific antibody production in culture supernatant by ELISA. In the present study, antigen-specific peripheral blood lymphocytes were isolated from subcutaneously immunized sheep and the parameters for maximizing in vitro antibody production by in vivo-induced antibody-secreting cells optimized for this species. Maximum antibody-secreting cell responses were observed in peripheral blood collected four days after antigen challenge. The addition of lipopolysaccharide and antisheep immunoglobulin had no effect on in vitro antibody secretion by blood antibody-secreting cells, while the effects of pokeweed mitogen were highly variable. However, the combination of anti-Ig and recombinant ovine interleukin-6 to peripheral blood lymphocyte cultures was found to markedly and consistently enhance specific antibody production. In unstimulated cultures, the optimal peripheral blood lymphocyte concentration for generating the greatest antibody responses was 5.0 x 107 cells per mL, but in cultures stimulated with recombinant ovine interleukin-6/antisheep immunoglobulin, the optimal cell concentration was lowered to approximately 1.0 x 107 cells per mL. In vitro, peak immunoglobulin production was usually achieved by day one in unstimulated cultures. In recombinant ovine interleukin-6/antisheep immunoglobulin-stimulated cultures, antibody levels were similar to unstimulated cultures by day one, however, the levels continued to rise during incubation to reach a maximum between days four and five of incubation. This optimized antibody-secreting cell culture assay is amenable for increasing the sensitivity and reducing the cell numbers required for quantitating antigen-specific antibody induction in large-scale immunization trials in sheep and other large animal species.     

Protocol of a prospective study on the diagnostic value of transcranial duplex scanning of the substantia nigra in patients with parkinsonian symptoms

Background  

Parkinson's disease (PD) is the second most common neurodegenerative disorder. As there is no definitive diagnostic test, its diagnosis is based on clinical criteria. Recently transcranial duplex scanning (TCD) of the substantia nigra in the brainstem has been proposed as an instrument to diagnose PD. We and others have found that TCD scanning of substantia nigra duplex is a relatively accurate diagnostic instrument in patients with parkinsonian symptoms. However, all studies on TCD so far have involved well-defined, later-stage PD patients, which will obviously lead to an overestimate of the diagnostic accuracy of TCD.     

Floristic variation and willow carr development within a southwest England wetland

Abstract. Woodland colonization on wetlands is considered to have a detrimental effect on their ecological value, even though detailed analysis of this process is lacking. This paper provides an evaluation of the ecological changes resulting from succession of poor fen (base‐poor mire) to willow wet woodland on Goss Moor NNR in Cornwall, UK. Different ages of willow carr were associated with eight understorey communities. During willow colonization, in the ground flora, there was a progressive decrease in poor fen species and an associated increase in woodland species, which appeared to be related to an increase in canopy cover and therefore shade. The most diverse community was found to be the most recent willow and was dominated by poor fen species. The oldest willow was the second most diverse and was associated with a reduction in poor fen species and an increase in woodland species. Architectural features were used successfully to assess the general condition and structure of willow. Tree height and DBH were identified as useful parameters to accurately assess willow age in the field. The implications of active intervention to remove willow in order to conserve the full range of communities within the hydrosere are discussed.     

Lucky rugose corals on crinoid stems: unusual examples of subepidermal epizoans from the Devonian of Morocco

Berkowski, B & Klug, C. 2011: Lucky rugose corals on crinoid stems: unusual examples of subepidermal epizoans from the Devonian of Morocco. Lethaia, Vol. 45, pp. 24–33. In the fossil record, evidence for true epizoans, i.e. living animals inhabiting other living host‐animals, is rather rare. A host reaction is usually needed to proof the syn vivo‐settling of the epizoan. Herein, we provide a first report of such an epizoan biocoenosis from various strata of the Early Devonian of Hamar Laghdad, the world‐renowned Moroccan mud‐mound locality. In this case, solitary rugose corals settled as larvae on crinoid stems, perhaps at a spot where the epidermis was missing for some reason (injury, disease). Both the crinoid and the coral began to grow around each other. By doing so, the affected crinoid columnals formed a swelling, where ultimately only an opening slightly larger than the coral orifice remained. We discuss both macroecological and small‐scale synecological aspects of this biocoenosis. The coral profited from its elevated home because it reached into more rapid currents providing the polyp with more food than at the densely populated seafloor, which was probably covered by a coral‐meadow around the mounds and hydrothermal vents. □Corals, crinoids, Early Devonian, epizoans, Morocco, Rugosa.     

Ultrastructural changes accompanying mitosporogenesis inEctocarpus parvus

The plurilocular zoosporangium of Ectocarpus parvus Saunders in initiated as a uniseriate branch from a vegetative cell. Subsequent anticlinal and periclinal divisions of the cells leads to enlargement of the sporangium and the formation of multiple locules. Each locule containes a single biflagellate zoospore. Ultrastructural changes accompanying these events include a reduction in the size of chromatophores, a reduction in the number of dictyosomes and the appearance of plasmalemmasomes in later stages. Enlargement of the mitochondria and a decrease in size of the nucleus occur in the final stages of zoospore formation. Comparison with the vegetative and sporogenous cells of other brown algae are made.     

Meta-analysis of the literature on diagnostic accuracy of SPECT in parkinsonian syndromes

Background  

Parkinson's disease (PD) is the second most common neurodegenerative disorder. One of the most widely used techniques to diagnose PD is a Single Photon Emission Computer Tomography (SPECT) scan to visualise the integrity of the dopaminergic pathways in the brain. Despite this there remains some discussion on the value of SPECT in the differential diagnosis of PD. We did a meta-analysis of all the existing literature on the diagnostic accuracy of both pre- and post-synaptic SPECT imaging in the differential diagnosis of PD.     

Above‐ and belowground linkages in Sphagnum peatland: climate warming affects plant‐microbial interactions

Peatlands contain approximately one third of all soil organic carbon (SOC). Warming can alter above‐ and belowground linkages that regulate soil organic carbon dynamics and C‐balance in peatlands. Here we examine the multiyear impact of in situ experimental warming on the microbial food web, vegetation, and their feedbacks with soil chemistry. We provide evidence of both positive and negative impacts of warming on specific microbial functional groups, leading to destabilization of the microbial food web. We observed a strong reduction (70%) in the biomass of top‐predators (testate amoebae) in warmed plots. Such a loss caused a shortening of microbial food chains, which in turn stimulated microbial activity, leading to slight increases in levels of nutrients and labile C in water. We further show that warming altered the regulatory role of Sphagnum‐polyphenols on microbial community structure with a potential inhibition of top predators. In addition, warming caused a decrease in Sphagnum cover and an increase in vascular plant cover. Using structural equation modelling, we show that changes in the microbial food web affected the relationships between plants, soil water chemistry, and microbial communities. These results suggest that warming will destabilize C and nutrient recycling of peatlands via changes in above‐ and belowground linkages, and therefore, the microbial food web associated with mosses will feedback positively to global warming by destabilizing the carbon cycle. This study confirms that microbial food webs thus constitute a key element in the functioning of peatland ecosystems. Their study can help understand how mosses, as ecosystem engineers, tightly regulate biogeochemical cycling and climate feedback in peatlands