新生溶血病患儿红细胞上致敏抗体对Rh 血型检测的影响

目的:探讨新生溶血病患儿红细胞致敏抗体对其Rh血型鉴定的影响。方法:采用抗球蛋白法、盐水法、微柱凝胶法(Rh血型测定型)、凝聚胺法和抗血清微柱凝胶法(Ig G型)五种方法对近三年来我院收集的163例新生溶血病患儿红细胞进行Rh血型检测,对五种检测结果不一致的患儿红细胞进行0.2 M 2-巯基乙醇抗体放散,比较放散后五种方法检测结果并验证其准确性。结果:29例直接抗体试验阳性患儿的五种Rh血型检测结果不一致,经0.2 M 2-巯基乙醇抗体放散后检测结果均一致。Rh血型准确性验证表明,红细胞放散测定的Rh血型完全符合临床现象。结论:患儿红细胞的致敏抗体达一定数量后,会影响抗球蛋白法、盐水法、微柱凝胶法(Rh血型测定型)、凝聚胺法和抗血清微柱凝胶法(Ig G型)对Rh血型鉴定,0.2M 2-巯基乙醇抗体放散法是一种正确鉴定新生儿Rh血型的简单可行的方法。     

Cuffing‐based photoacoustic flowmetry in humans in the optical diffusive regime

Measuring blood flow speed in the optical diffusive regime in humans has been a long standing challenge for photoacoustic tomography. In this work, we proposed a cuffing‐based method to quantify blood flow speed in humans with a handheld photoacoustic probe. By cuffing and releasing the blood vessel, we can measure the blood flow speed downstream. In phantom experiments, we demonstrated that the minimum and maximum measurable flow speeds were 0.035 mm/s and 42 mm/s, respectively. In human experiments, flow speeds were measured in three different blood vessels: a radial artery in the right forearm, a radial artery in the index finger of the right hand, and a radial vein in the right forearm. Taking advantage of the handheld probe, our method can potentially be used to monitor blood flow speed in the clinic and at the bedside.

     

Community dynamics of nematodes after Larsen ice‐shelf collapse in the eastern Antarctic Peninsula

Free‐living marine nematode communities of the Larsen B embayment at the eastern Antarctic Peninsula were investigated to provide insights on their response and colonization rate after large‐scale ice‐shelf collapse. This study compares published data on the post‐collapse situation from 2007 with new material from 2011, focusing on two locations in the embayment that showed highly divergent communities in 2007 and that are characterized by a difference in timing of ice‐shelf breakup. Data from 2007 exposed a more diverse community at outer station B.South, dominated by the genus Microlaimus. On the contrary, station B.West in the inner part of Larsen B was poor in both numbers of individuals and genera, with dominance of a single Halomonhystera species. Re‐assessment of the situation in 2011 showed that communities at both stations diverged even more, due to a drastic increase in Halomonhystera at B.West compared to relatively little change at B.South. On a broader geographical scale, it seems that B.South gradually starts resembling other Antarctic shelf communities, although the absence of the genus Sabatieria and the high abundance of Microlaimus still set it apart nine years after the main Larsen B collapse. In contrast, thriving of Halomonhystera at B.West further separates its community from other Antarctic shelf areas.     

Temporal variation in selection on male and female traits in wild tree crickets

Understanding temporal variation in selection in natural populations is necessary to accurately estimate rates of divergence and macroevolutionary processes. Temporal variation in the strength and direction of selection on sex‐specific traits can also explain stasis in male and female phenotype and sexual dimorphism. I investigated changes in strength and form of viability selection (via predation by wasps) in a natural population of male and female tree crickets over 4 years. I found that although the source of viability stayed the same, viability selection affected males and females differently, and the strength, direction and form of selection varied considerably from year to year. In general, males experienced significant linear selection and significant selection differentials more frequently than females, and different male traits experienced significant linear selection each year. This yearly variation resulted in overall weak but significant convex selection on a composite male trait that mostly represented leg size and wing width. Significant selection on female phenotype was uncommon, but when it was detected, it was invariably nonlinear. Significant concave selection on traits representing female body size was observed in some years, as the largest and smallest females were preyed on less (the largest may have been too heavy for flying wasps to carry). Viability selection was significantly different between males and females in 2 of 4 years. Although viability selection via predation has the potential to drive phenotypic change and sexual dimorphism, temporal variation in selection may maintain stasis.     

Assessing in vivo dynamics of multiple quality attributes from a therapeutic IgG4 monoclonal antibody circulating in cynomolgus monkey

Characterization of biopharmaceutical proteins and assessment and understanding of the critical quality attributes (CQAs) is a significant part of biopharmaceutical product development and is routinely performed in vitro. In contrast, systematic analysis of the quality attributes in vivo is not as widespread, although metabolism and clearance of multiple variants of therapeutic proteins administered to non-human primates and human subjects may have a different impact on safety, efficacy and exposure. The major hurdles of such studies are usually sample availability and technical capability. In this study, we used affinity purification coupled with liquid chromatography and mass spectrometric analysis of the digested protein for consistent and simultaneous detection of the full amino acid sequence of a therapeutic IgG4 monoclonal antibody, MAB1. This methodology allowed us to assess in vivo changes of all sequence-related modifications and quality attributes of MAB1 over the duration of a preclinical pharmacokinetic study in cynomolgus monkeys.     

Feeder-free Derivation of Melanocytes from Human Pluripotent Stem Cells

Human pluripotent stem cells (hPSCs) represent a platform to study human development in vitro under both normal and disease conditions. Researchers can direct the differentiation of hPSCs into the cell type of interest by manipulating the culture conditions to recapitulate signals seen during development. One such cell type is the melanocyte, a pigment-producing cell of neural crest (NC) origin responsible for protecting the skin against UV irradiation. This protocol presents an extension of a currently available in vitro Neural Crest differentiation protocol from hPSCs to further differentiate NC into fully pigmented melanocytes. Melanocyte precursors can be enriched from the Neural Crest protocol via a timed exposure to activators of WNT, BMP, and EDN3 signaling under dual-SMAD-inhibition conditions. The resultant melanocyte precursors are then purified and matured into fully pigmented melanocytes by culture in a selective medium. The resultant melanocytes are fully pigmented and stain appropriately for proteins characteristic of mature melanocytes.     

Behavioral and functional strategies during tool use tasks in bonobos

Different primate species have developed extensive capacities for grasping and manipulating objects. However, the manual abilities of primates remain poorly known from a dynamic point of view. The aim of the present study was to quantify the functional and behavioral strategies used by captive bonobos (Pan paniscus) during tool use tasks. The study was conducted on eight captive bonobos which we observed during two tool use tasks: food extraction from a large piece of wood and food recovery from a maze. We focused on grasping postures, in‐hand movements, the sequences of grasp postures used that have not been studied in bonobos, and the kind of tools selected. Bonobos used a great variety of grasping postures during both tool use tasks. They were capable of in‐hand movement, demonstrated complex sequences of contacts, and showed more dynamic manipulation during the maze task than during the extraction task. They arrived on the location of the task with the tool already modified and used different kinds of tools according to the task. We also observed individual manual strategies. Bonobos were thus able to develop in‐hand movements similar to humans and chimpanzees, demonstrated dynamic manipulation, and they responded to task constraints by selecting and modifying tools appropriately, usually before they started the tasks. These results show the necessity to quantify object manipulation in different species to better understand their real manual specificities, which is essential to reconstruct the evolution of primate manual abilities.