The demography of trout lily (Erythronium americanum Ker.) in Nova Scotia

The age structures of both native and transplanted populations of the perennial herb, trout lily (Erythronium americanum), were analysed and found to have age-independent mortality rates. Cohort survival was greatest in populations growing on hardwood forested flood plains (60%), less in populations from gently sloping terraces with pit-and-mound microrelief (53%) and smallest (45%) for colonies on slopes steeper than 15°. The former habitat-type is the optimum for trout lily in Nova Scotia and in it the proportion of flowering bulbs can reach 35%. The second named habitat is widespread and characterised by fewer flowering bulbs (5–10%). In the latter habitat flowering bulbs are uniformly rare. Trout lily bulbs tend to be sterile until at least their eighth year. The high mortality rates of populations on steeply sloping, hardwood forested ground ensure minimal survival of bulbs beyond their sixth year. In the other two named habitats sufficient numbers of bulbs reach ages of 8 or 9 years for some to make the translation from the sterile to the flowering form. In all the habitats studied in Nova Scotia, propagation is typically by either runners or, less importantly, daughter bulbs, with the peak of activity in the bulbs third and fourth years. The plants of flood plains showed the greatest rates of vegetative propagation, by cohort, but many of the bulbs from colonies growing on steep slopes lacked runners or daughter bulbs. As all bulbs for the transplant experiments came from a single clone it can be concluded that trout lily plants in Nova Scotia have a sufficiently large genetic endowment for them to behave in the same manner as native populations of the species in the several habitats represented in the province.The figures were drafted in the cartography section of the University of Canterbury. The National Research Council of Canada supported the research with a series of grants.     

Survival of priceless cells: active and passive protection of embryonic stem cells against immune destruction

This review focuses on our current knowledge of the mechanisms employed by embryonic stem (ES) cells to avoid destruction by cell-mediated immune responses. Recently, ES cells have been found to shield themselves against cytotoxic effector cells by expressing CD95L and serine protease inhibitor SPI-6 mediating apoptosis of the cytotoxic cells and inactivation of granzyme B, respectively. These findings are discussed in view of their implications for using ES cell-derived transplants in regenerative medicine as well as for our understanding of early embryonic stages during invasion and implantation.     

Design,synthesis, and evaluation of 4,6-diaminonicotinamide derivatives as novel and potent immunomodulators targeting JAK3

In organ transplantation, T cell-mediated immune responses play a key role in the rejection of allografts. Janus kinase 3 (JAK3) is specifically expressed in hematopoietic cells and associated with regulation of T cell development via interleukin-2 signaling pathway. Here, we designed novel 4,6-diaminonicotinamide derivatives as immunomodulators targeting JAK3 for prevention of transplant rejection. Our optimization of C4- and C6-substituents and docking calculations to JAK3 protein confirmed that the 4,6-diaminonicotinamide scaffold resulted in potent inhibition of JAK3. We also investigated avoidance of human ether-a-go-go related gene (hERG) inhibitory activity. Selected compound 28 in combination with tacrolimus prevented allograft rejection in a rat heterotopic cardiac transplantation model.     

Effects of age, gender and time on receptor expression and anti-Aspergillus functions of human phagocytes

Phagocytes play a central role in immune defense. Their dysfunction predisposes to infections. This study determined the expression level of nine receptors involved in Aspergillus immune response as well as the values of phagocytosis and production of radical oxygen species after Aspergillus stimulation, in a healthy adult population.The expression values of the CD11b, CD11c, CD14, CD18, CD35, CD181, CD182, CD282 and CD284 receptors on peripheral human monocytes and granulocytes was established. A heterogenous expression of the CD282 on granulocytes was observed as CD181, CD182 and CD284 on monocytes. Similarly, we observed considerable variation in the expression of these receptors over time. Only CD282 on granulocytes varied with sex. No variation with age was observed. Adherence of Aspergillus conidia to phagocytes was dependent of individual, sex, age and time. A better characterization of these innate immunity parameters is necessary to develop in the future an immunologic surveillance strategy for transplant recipients.     

The Evolution of Quality Systems in Human Bone Banking: The U.S. Experience

This paper illustrates the evolutionary changes that have taken place in human bone banking in the United States since the 1970s to the present, with an emphasis on quality control systems. Specific examples of quality controls are outlined, along with their intended purposes. Particular importance is placed on the gradual change in emphasis from bacteriological concerns to viral concerns and quality control systems.     

Technique of Porcine Liver Procurement and Orthotopic Transplantation using an Active Porto-Caval Shunt

The success of liver transplantation has resulted in a dramatic organ shortage. Each year, a considerable number of patients on the liver transplantation waiting list die without receiving an organ transplant or are delisted due to disease progression. Even after a successful transplantation, rejection and side effects of immunosuppression remain major concerns for graft survival and patient morbidity. Experimental animal research has been essential to the success of liver transplantation and still plays a pivotal role in the development of clinical transplantation practice. In particular, the porcine orthotopic liver transplantation model (OLTx) is optimal for clinically oriented research for its close resemblance to human size, anatomy, and physiology. Decompression of intestinal congestion during the anhepatic phase of porcine OLTx is important to guarantee reliable animal survival. The use of an active porto-caval-jugular shunt achieves excellent intestinal decompression. The system can be used for short-term as well as long-term survival experiments. The following protocol contains all technical information for a stable and reproducible liver transplantation model in pigs including post-operative animal care.     

Lipid and fatty acid biomarkers as proxies for environmental contamination in caged mussels Mytilus galloprovincialis

Mussels (Mytilus galloprovincialis) were transplanted from a reference site (Syracuse harbour) to an impacted site (Augusta Bay) from January to July 2013 to assess the biochemical response of caged mussels to high trace element and polycyclic aromatic hydrocarbon (PAH) contamination, using lipid and fatty acid (FA) biomarkers. Sediment and mussels were analysed to assess contaminant bioavailability in the study sites and bioaccumulation in mussel tissue. Trace elements (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, Zn) and PAHs were significantly higher in mussels from Augusta than in those from Syracuse, mirroring the different environmental contamination. The biological impact quotient (BIQs), which indicates the potential biological impact of mussel-accumulated contaminants, reflected the highest contaminant concentrations found in Augusta and their temporal trend, which increased from the start of the experiment to 3–4 months after transplanting, followed by a decrease, as indication of mussel detoxification processes. Lower condition index (CI) and phospholipids (PL), as well as higher total (TL) and neutral lipids (NL) in mussels from Augusta, indicated the occurrence of a physiological and biochemical stress response to pollutant exposure and accumulation. Differences in FA composition, especially polyunsaturated (PUFA), essential (EFA) and non-methylene interrupted dienoic (NMID) FAs between the study sites revealed the occurrence of stress-induced lipid peroxidation, followed by compensatory/adaptive processes in Augusta mussels. The marked increase in bacterial biomarkers, mainly cyclopropyl (CY) FAs, reflecting the greater bioaccumulation of chemicals in the Augusta mussels, may be the result of bacterial infections or symbiosis with bacteria involved in detoxification processes.     

Determining effects of suspended sediment on condition of a suspension feeding bivalve (Atrina zelandica): results of a survey, a laboratory experiment and a field transplant experiment

The horse mussel Atrina zelandica (Gray) is a large, suspension feeding pinnid bivalve, common in coastal and estuarine areas of northern New Zealand. As a suspension feeder, Atrina is likely to be influenced by suspended sediment loads. We conducted a laboratory experiment to determine the effect of short-term elevations in turbidity levels, such as those commonly recorded during storms, on the physiological condition and clearance rates of Atrina. We also conducted a field survey and a 3-month transplant experiment at multiple sites along a gradient of increasing suspended sediment load in a New Zealand estuary. Laboratory clearance rates of Atrina declined above a threshold suspended sediment concentration, and Atrina physiological condition at the end of this experiment was lower in high cf. low turbidity treatments. Decreases in Atrina condition were detected after exposure to elevated levels for only 3 days. The field survey and transplant experiment provided empirical evidence of a strong, negative effect of increasing suspended sediment flux on the physiological condition of Atrina. We suggest that relationships between the physiological condition of suspension feeders and sediment settling flux could provide a link between sediment inputs, which commonly occur as a result of catchment runoff during rainfall events, and the ecological health of estuarine and shallow coastal areas. Our study also demonstrated that Atrina have a natural distribution limit controlled by suspended sediment load. Thus, there is potential for larger-scale functional and structural effects on benthic communities in estuarine and coastal areas with high rates of sedimentation.     

移植视网膜NOS阳性神经元的发育

目的 观察不同年龄组段大鼠正常视网膜及移植视网膜内NOS阳性神经元的发育情况及其定位分布。方法 实验分正常视网膜发育组和移植视网膜发育组,应用还原型烟酰胺腺嘌呤二核苷酸磷酸（NADPH）组织化学方法显示。结果 1、NOS阳性神经元最早出现于生后第五天（P5）,P18时阳性神经元数目达到最高峰,2、移植视网膜具有正常视网膜的各层结构和相似的生长规律,NOS阳性神经元在生后第4天移植视网膜（TP4）中出现,TP12数量达到高峰值,TP22后降至正常成年鼠水平。结论 根据NOS阳性神经元的定位,分布,推测其为无长突细胞,移位无长突细胞及节细胞。