SIGN-R1, a novel C-type lectin expressed by marginal zone macrophages in spleen,mediates uptake of the polysaccharide dextran

The marginal zone macrophages of the spleen are implicated in the clearance of polysaccharides, but underlying mechanisms need to be pinpointed. SIGN-R1 is one of five recently identified mouse genes that are homologous to human DC-SIGN and encode a single, external, C-terminal C-type lectin domain. We find that a polyclonal antibody to a specific SIGN-R1 peptide reacts primarily and strongly with a subset of macrophages in the marginal zone of spleen and lymph node medulla. In both sites, SIGN-R1 exists primarily in an aggregated form, resistant to dissociation into monomers upon boiling in SDS under reducing conditions. Upon transfection into three different cell lines, high-mol.-wt forms bearing SIGN-R1 are expressed, as well as reactivity with ER-TR9, a mAb previously described to react selectively with marginal zone macrophages. SIGN-R1-expressing macrophages preferentially sequester dextrans following i.v. injection. Likewise, when phagocytic cells are enriched from spleen and tested in culture, dextran is selectively endocytosed by a subset of very large SIGN-R1(+) cells representing approximately 5% of total released macrophages. Uptake of FITC-dextran by these macrophages in vivo and in vitro is blocked by ER-TR9 and polyclonal anti-SIGN-R1 antibodies. Following transfection with SIGN-R1, cell lines become competent to endocytose dextrans. The dextran localizes primarily to compartments lacking transferrin receptor and the LAMP-1 CD107a panlysosomal antigen. Therefore, SIGN-R1 mediates the uptake of dextran polysaccharides, and it is predominantly expressed in the macrophages of the splenic marginal zone and lymph node medulla.     

Estimating the relative frequency of leukodystrophies and recommendations for carrier screening in the era of next‐generation sequencing

Leukodystrophies are a heterogeneous group of heritable disorders characterized by abnormal brain white matter signal on magnetic resonance imaging (MRI) and primary involvement of the cellular components of myelin. Previous estimates suggest the incidence of leukodystrophies as a whole to be 1 in 7,000 individuals, however the frequency of specific diagnoses relative to others has not been described. Next generation sequencing approaches offer the opportunity to redefine our understanding of the relative frequency of different leukodystrophies. We assessed the relative frequency of all 30 leukodystrophies (associated with 55 genes) in more than 49,000 exomes. We identified a relatively high frequency of disorders previously thought of as very rare, including Aicardi Goutières Syndrome, TUBB4A‐related leukodystrophy, Peroxisomal biogenesis disorders, POLR3‐related Leukodystrophy, Vanishing White Matter, and Pelizaeus‐Merzbacher Disease. Despite the relative frequency of these conditions, carrier‐screening laboratories regularly test only 20 of the 55 leukodystrophy‐related genes, and do not test at all, or test only one or a few, genes for some of the higher frequency disorders. Relative frequency of leukodystrophies previously considered very rare suggests these disorders may benefit from expanded carrier screening.     

Heterotrimeric G proteins and the platelet-derived growth factor receptor-beta contribute to hypoxic proliferation of smooth muscle cells

Hypoxic proliferation of pulmonary arterial smooth muscle cells (PASMC) is mitogen dependent, but the signaling pathways mediating hypoxia-induced cell growth are not well understood. We investigated hypoxic proliferation in primary cultures from porcine pulmonary artery smooth muscle. The cells were grown in medium with or without platelet-derived growth factor (PDGF)-B, a potent smooth muscle cell mitogen. Hypoxia induced upregulation of PDGF receptor-beta expression, the primary receptor for PDGF-B. However, PDGF-B-mediated hypoxic enhancement of proliferation was abolished by pertussis toxin, indicating (1) involvement of heterotrimeric Galpha i proteins and (2) minimal effect of increased PDGF receptor expression in hypoxic enhancement of proliferation. We treated PASMC with labeled, nonhydrolyzable analogs of GTP to determine directly if GTP binding proteins were activated by hypoxia in PASMC. We show that hypoxia stimulates GTP incorporation in PASMC both in the presence and absence of PDGF-B. Serum-starved PASMC are able to increase their incorporation of GTP after only 10 min of hypoxia, and this response is not pertussis toxin sensitive. In serum-starved PASMC, we show that hypoxia stimulates incorporation of GTP into a 44-kD protein. The results show that heterotrimeric G proteins are involved in hypoxia-induced signaling in pulmonary vascular smooth muscle cells.     

Balloon sphincteroplasty in pediatric laparoscopic common bile duct exploration

The management of choledocholithiasis in children and teenagers is often a two-procedure process with laparoscopic cholecystectomy (LC) and either pre- or post-operative endoscopic retrograde cholangiopancreatography (ERCP). The addition of laparoscopic common bile duct exploration (LCBDE) during LC can provide definitive treatment for choledocholithiasis during a single anesthetic event. In an effort to minimize sedation and radiation exposure from fluoroscopy, we have employed dilating balloons via a transcystic approach to stretch the sphincter of Oddi with subsequent ductal flushing. We describe the technique of balloon sphincteroplasty as a straightforward adjunct within the pediatric surgeon's skill set to manage choledocholithiasis during LC and our clinical experience.     

蘡Ao中分离的多酚化合物

目的分离鉴定蘡Ao地上部分的化学成分。方法通过硅胶柱色谱，Sephadex LH-20及制备HPLC方法分离，对其进行理化常数和光谱分析确定结构。结果自蘡Ao地上部分分离得到11个多酚化合物，均属首次分离。结论化合物1为新化合物，经鉴定其结构为3，5-二甲氧基-4-羟基苯丙醇-9-氧-β-D-吡喃葡萄糖苷。     

Infant brain imaging using magnetoencephalography: Challenges,solutions, and best practices

The excellent temporal resolution and advanced spatial resolution of magnetoencephalography (MEG) makes it an excellent tool to study the neural dynamics underlying cognitive processes in the developing brain. Nonetheless, a number of challenges exist when using MEG to image infant populations. There is a persistent belief that collecting MEG data with infants presents a number of limitations and challenges that are difficult to overcome. Due to this notion, many researchers either avoid conducting infant MEG research or believe that, in order to collect high‐quality data, they must impose limiting restrictions on the infant or the experimental paradigm. In this article, we discuss the various challenges unique to imaging awake infants and young children with MEG, and share general best‐practice guidelines and recommendations for data collection, acquisition, preprocessing, and analysis. The current article is focused on methodology that allows investigators to test the sensory, perceptual, and cognitive capacities of awake and moving infants. We believe that such methodology opens the pathway for using MEG to provide mechanistic explanations for the complex behavior observed in awake, sentient, and dynamically interacting infants, thus addressing core topics in developmental cognitive neuroscience.     

The development and testing of an algorithm for diagnosis of active labour in primiparous women

OBJECTIVES: to describe the development and testing of an algorithm for diagnosis of active labour in primiparous women. DESIGN: qualitative and quantitative methods were used. A literature review was first conducted to identify the key cues for inclusion in the algorithm. Focus groups of midwives were then conducted to assess content validity, finally a vignette study assessed the inter-rater reliability of the algorithm. SETTING: midwives from two study sites were invited to participate. Data were collected during 2002 and 2003. PARTICIPANTS: midwives from the first site took part in the focus groups (n=13), completed vignettes (n=19), or both. Midwives from the second site then completed vignettes (n=17). FINDINGS: an algorithm, developed from the key informational cues reported in the literature, was validated in relation to content validity by the findings from the focus groups. Inter-rater reliability was tested using vignettes of admission case histories and was found to be moderate in the first test (K=0.45). However, after modifying the algorithm the kappa score was 0.86, indicating a high level of agreement. KEY CONCLUSIONS: diagnosis of labour may be straightforward on paper but is frequently problematic in practice. This may be because the diagnosis of labour is made in a high pressured environment where conflicting pressures of workload, limited resources and emotional pressures add to the complexity of the judgement. IMPLICATIONS FOR PRACTICE: we offer a valid and reliable decision-support tool as an aid for diagnosis of labour. The evaluation of the implementation of this tool is under way and will determine whether it is effective in reducing unnecessary admissions and improving clinical outcomes for women.     

HPV and HPV Vaccines: The Knowledge Levels, Opinions, and Behavior of Parents

To measure parent knowledge levels and opinions related to the human papillomavirus (HPV) and the two vaccines used to prevent it. To measure parent behavior in terms of whether or not to have their children vaccinated. Between June 19, 2012, and August 24, 2012, questionnaires were distributed to parents while waiting for their child to see their pediatrician at a local group practice. The survey was reviewed for face validity by College of Pharmacy social science and clinical faculty members, and an earlier version of it had been used successfully in a published study of biomedical students’ knowledge of and attitudes toward the HPV vaccine. 129 usable surveys were obtained. 48.1 % of subjects said they learned about the HPV vaccines from the media, while 47.3 % identified health care practitioner(s) as a source of knowledge. The mean score on a 20-item knowledge test regarding the infection and vaccines was 36 % (range 0–80 %). Opinions on the subject varied widely. For example, 22.4 % of subjects agreed that schools should require that students be vaccinated before enrolling, while 3.2 % agreed that vaccination causes patients to become sexually active. Subjects reported vaccination status for 253 children (mean age 13) as follows: 33 % vaccinated; 28 % not vaccinated but will be; 11 % will never be vaccinated; and 28 % not decided. These results are somewhat encouraging, because many parents are hearing about the vaccines from their providers. Although not an equally valid source, the media are also raising awareness. Based on the knowledge and opinion results of this study, there is a need for pharmacists and other providers to educate their patients about the vaccines and the virus and to converse with them regarding the moral and psychological implications of vaccination. Still, it is encouraging that these subjects had or plan to have over half (61 %) of their children vaccinated.     

The Possible Role of Source Misattributions in the Creation of False Beliefs Among Preschoolers

In this article the authors examine one possible factor in the creation of false beliefs among preschool-aged children, namely, source misattributions. The authors present the results from an ongoing program of research which suggest that source misattributions could be a mechanism underlying children's false beliefs about having experienced fictitious events. Findings from this program of research indicate that, although all children are susceptible to making source misattributions, very young children may be disproportionately vulnerable to these kinds of errors. This vulnerability leads younger preschoolers, on occasion, to claim that they remember actually experiencing events that they only thought about or were suggested by others. These results are discussed in the context of the ongoing debate over the veracity and durability of delayed reports of early memories, repressed memories, dissociative states, and the validity risks posed by therapeutic techniques that entail repeated visually guided imagery inductions.