High-level expression of the ER-MP58 antigen on mouse bone marrow hematopoietic progenitor cells marks commitment to the myeloid lineage

Studies on the early events in the differentiation of the nonspecific immune system require the identification and isolation of myeloid-committed progenitor cells. Using the monoclonal antibodies (mAb) ER-MP12 and ER-MP20, generated against immortalized macrophage precursors, we have shown previously that the earliest macrophage colony-stimulating factor (M-CSF)-responsive cells in the bone marrow have the ER-MP12(hi)20- phenotype. In addition, we found that the ER-MP12(hi)20- subset (comprising about 2% of total nucleated marrow) contains progenitor cells of all hematopoietic lineages. Aiming at the identification and purification of the myeloid progenitor cells within the ER-MP12(hi)20- subset, we used ER-MP58, a marker expressed at high level by all M-CSF-responsive bone marrow progenitors. With this marker the ER-MP12(hi)20- cell population could be divided into three subfractions: one with absent or low level ER-MP58 expression, one with intermediate, and one with high ER-MP58 expression. These subfractions were isolated by fluorescence-activated cell sorting and tested in vitro and in vivo for their differentiation capacities. In addition, the expression of ER-MP58 on stem cell subsets was examined in the cobblestone area-forming cell (CAFC) assay. Our data indicate that in the ERMP12(hi)20- subpopulation myeloid-committed progenitors are characterized by high-level expression of the ER-MP58 antigen, whereas cells with other or broader differentiation capacities have an ER-MP58 negative/low or intermediate phenotype. These myeloid-committed progenitors have no significant repopulating ability in vivo, in contrast to the ER-MP58 intermediate cells. Primitive CAFC-28/35, corresponding to cells providing long-term hematopoietic engraftment in vivo, also did not express the ER-MP58 Ag at a high level. Thus, cells committed to the myeloid lineage can be separated from progenitor cells with other differentiation capacities by means of multiparameter cell sorting using ER-MP58 in combination with ER-MP12 and ER-MP20

The effects of perceived parenting style on the propensity for illicit drug use: the importance of parental warmth and control

Introduction and Aims. Research in adolescents has shown that parental warmth and control are important factors in drug use. The present study focused upon investigating perceived parental warmth and control in a sample of post-adolescent ecstasy/polydrug users, and investigating their relationship to severity of drug use. Design and Methods. A total of 128 (65 male) ecstasy/polydrug users, 51 (17 male), cannabis-only users and 54 (13 male) non-users were recruited from a university population. All participants completed the parenting styles and drug use questionnaires. Results. Compared to non-users, a greater proportion of ecstasy/polydrug users characterised their parents’ style as neglectful. The modal style endorsed by non-users was authoritative. Those who rated their parents’ style as authoritative had significantly lower lifetime consumption and average dose of ecstasy relative to those describing their parents as neglectful. Again, relative to those describing their parents as neglectful, participants from authoritarian backgrounds had significantly smaller lifetime consumption of ecstasy and cocaine and significantly smaller average doses of cannabis, ecstasy and cocaine. Contrary to expectation, there was no significant association between perceived parental warmth and the severity of ecstasy use. Discussion and Conclusions. The present study is, to our knowledge, the first to quantify drug use, and relate it to perceived parental practices in a post-adolescent sample of ecstasy/polydrug users. The results provide further support for the relationship between perceived parental control and drug use

Finding the Meanings of College Drinking: An Analysis of Fraternity Drinking Stories

College drinking has traditionally been studied from a public health perspective that attempts to quantify behavior as a means toward description, explanation, and intervention. This article offers a critical and cultural approach to understanding the meanings and functions of high-risk drinking and the ways in which those meanings are reproduced within the culture. Data were collected via an ethnographic study of fraternity members at a large midwestern university to explore the communication of excessive drinking norms. Viewed from various narrative and structural theories, the study examines collected drinking stories as a source for analyzing the construction of meanings surrounding drunkenness for the fraternity subculture. Five themes emerged as functions of drunkenness for the culture. Implications for prevention are discussed

Engineering Small HOMO–LUMO Gaps in Polycyclic Aromatic Hydrocarbons with Topologically Protected States

Topological phases in laterally confined low-dimensional nanographenes have emerged as versatile design tools that can imbue otherwise unremarkable materials with exotic band structures ranging from topological semiconductors and quantum dots to intrinsically metallic bands. The periodic boundary conditions that define the topology of a given lattice have thus far prevented the translation of this technology to the quasi-zero-dimensional (0D) domain of small molecular structures. Here, we describe the synthesis of a polycyclic aromatic hydrocarbon (PAH) featuring two localized zero modes (ZMs) formed by the topological junction interface between a trivial and nontrivial phase within a single molecule. First-principles density functional theory calculations predict a strong hybridization between adjacent ZMs that gives rise to an exceptionally small HOMO–LUMO gap. Scanning tunneling microscopy and spectroscopy corroborate the molecular structure of 9/7/9-double quantum dots and reveal an experimental quasiparticle gap of 0.16 eV, corresponding to a carbon-based small molecule long-wavelength infrared (LWIR) absorber