We have identified a gene that has a high level of mRNA expression in undifferentiated, multipotential hematopoietic cells (FDCP-Mix) and that downregulates both transcript and protein, as these cells are induced to differentiate into mature myeloid cells. Sequence analysis of this gene has identified it as a serine protease inhibitor EB22/3 (serpin 2A). Constitutive expression of serpin 2A in FDCP-Mix cells was associated with an increase in the clonogenic potential of the cells and with a delay in the appearance of fully mature cells in cultures undergoing granulocyte macrophage differentiation when compared with control cells. Serpin 2A was also found to be expressed in bone marrow-derived bipotent granulocyte macrophage progenitor cells (GM-colony forming cell [CFC]), but not in erythrocyte progenitor cells from day 15 fetal liver. Expression of serpin 2A also showed a marked up regulation during the activation of cytotoxic suppressor CD8+ T cells, with a clear lag between the appearance of transcript and detection of protein.

Amino Acid Sequence↗

PubMed1997

Access to emergency care under TennCare: do patients understand the system?

STUDY OBJECTIVE: To determine patient understanding of how to properly gain access to urgent and emergency medical care under TennCare, a government-mandated managed health care initiative designed to replace Medicaid in Tennessee. METHODS: We prospectively surveyed a convenience sample of ED patients at university hospital ED with an annual census of 50,000 during two periods (summer 1994 and summer 1995). In 1994, 250 TennCare patients were enrolled (part 1). In 1995, 199 were enrolled (part 2). RESULTS: Patients from seven different TennCare managed care organizations (MCOs) were interviewed. Thirty-eight percent of part 1 patients and 37% of part 2 patients did not have or did not know the names of their primary care physicians (PCPs). Fifty-eight percent of the part 1 patients who knew their PCPs' names had never visited them. This figure had decreased to 25% by the time part 2 patients were surveyed. Seventy-three percent of part 1 patients interviewed did not call their PCPs before coming to the ED. This figure had decreased to 48% by the time part 2 patients were interviewed. Thirty-two percent of part 1 patients were aware that they were supposed to contact the PCP before visiting the ED, whereas 94% of part 2 patients were aware of this requirement. Thirty-one percent of part 1 patients and 40% of part 2 patients who tried to contact their PCPs were unsuccessful, most often because of a delay on the part of PCPs in returning calls. Fifty-six percent of part 1 patients and 69% of part 2 patients did not know that they might be held responsible for the bill if an ED visit was not considered a true emergency and was not approved by the MCO. CONCLUSION: Improvements in communication of pertinent information must be implemented in managed care systems such as TennCare to better inform participants of the proper use of the system. MCOs will not reduce inappropriate use of the ED if patients are not aware of their responsibilities and do not know their PCPs or how to gain access to them. PCP responsiveness to patients must also be improved.

Adult↗

PubMed1997

Molecular heterogeneity of regulatory elements of the mouse GATA-1 gene.

The GATA-1 gene encodes a transcription factor expressed in early multipotent haemopoietic progenitors, in more mature cells of the erythroid, megakaryocytic and other lineages, but not in late myeloid precursors; its function is essential for the normal development of the erythroid and megakaryocytic system. To define regulatory elements of the mouse GATA-1 gene, we mapped DNaseI-hypersensitive sites in nuclei of erythroid and haemopoietic progenitor cells. Five sites were detected. The two upstream sites, site 1 and site 2, represent a new and a previously defined erythroid enhancer respectively. The site 1 enhancer activity depends both on a GATA-binding site (also footprinted in vivo) and on several sites capable of binding relatively ubiquitous factors. A DNA fragment encompassing site 1, placed upstream of a GATA-1 minimal promoter, is able to drive expression of a simian virus 40 (SV40) T-antigen in the yolk sac, but not bone-marrow cells, obtained from mice transgenic for this construct, allowing in vitro establishment of immortalized yolk-sac cells. A similar construct including site 2, instead of site 1, and previously shown to be able to immortalize adult marrow cells is not significantly active in yolk-sac cells. Sites 4 and 5, located in the first large intron, have no enhancer activity; they include a long array of potential Ets-binding sites. MnlI restriction sites, overlapping some of the Ets sites, are highly accessible, in intact nuclei, to MnlI. Although these sites are present in all GATA-1-expressing cells studied, they are the only strong sites detectable in FDCP-mix multipotent progenitor cells, most of which do not yet express GATA-1. The data indicate that appropriate GATA-1 regulation may require the co-operation of different regulatory elements acting at different stages of development and cell differentiation.

Animals↗

PubMed1997

Administration to humans of ORG 21465, a water soluble steroid i.v. anaesthetic agent.

Ten male volunteers received a 1-min i.v. infusion of a new water soluble steroid anaesthetic agent, ORG 21465. Individuals received doses ranging from 0.8 to 1.8 mg kg-1. All subjects experienced venous pain at the site of injection; those receiving 1.0 mg kg-1 or more became anaesthetized. There was no evidence of histamine release and apnoea did not occur. Excitatory phenomena were observed in all subjects and were dose related; no spikes were seen on the EEG. Pharmacokinetic analysis supported a three-compartment (non-weight-related) model with compartmental volumes V1, V2 and V3 of 4.31, 14.2 and 89.4 litre, respectively. Clearance from the central compartment V1 was 1.55 litre min-1. Inter-compartmental clearances Q1 and Q2 were 2.54 and 1.79 litre min-1. We found that ORG 21465 was an effective anaesthetic in humans. The relationship between sedation, anaesthesia and excitation requires further exploration.

Adult↗

PubMed1997

Computer-controlled infusion of ORG 21465, a water soluble steroid i.v. anaesthetic agent, into human volunteers.

ORG 21465 has been found to possess anaesthetic properties in humans and its pharmacokinetics are known. We performed this study to confirm the characteristics associated with its administration and to define its pharmacodynamic profile, in particular to explore the relationship between sedation, anaesthesia, excitation and plasma drug concentrations. A water soluble preparation of ORG 21465 was administered to six male volunteers as a series of three 15-min computer-controlled, pharmacokinetic model-driven infusions targeting three exponentially increasing plasma concentrations: 0.5, 1 and 2 micrograms ml-1. The clinical characteristics of the resultant sedation and anaesthesia were observed. Plasma concentrations of ORG 21465 were measured during and for 500 min after the infusions and the EEG recorded. A sigmoid e-max effect compartment pharmacodynamic model was fitted to the plasma concentrations and an EEG derivative (spectral edge frequency (SEF)). Anaesthesia with ORG 21465 was associated with involuntary movements in all subjects. A steady state concentration of 1180 ng ml-1 depressed SEF by 50%, the Hill factor describing the sigmoid nature of the concentration-response curve was 1.42 and the equilibration rate constant of the biophase was 0.112 min-1. Anaesthesia with ORG 21465 was found to be unsatisfactory because of involuntary movements and slow equilibration with the biophase.

Adult↗

PubMed1997