Prostanoid stimulation of anion secretion in guinea-pig gastric and ileal mucosa is mediated by different receptors.

1. The receptors that mediate stimulation of anion secretion by prostanoids in isolated preparations of guinea-pig gastric and ileal mucosa have been compared by use of selective prostanoid agonists and antagonists. 2. In gastric mucosa, the relative potency of agonists suggested that the control of anion secretion in this tissue was complex and may be mediated by EP2, EP3, and TP receptors. A role for TP receptors was confirmed with the TP-selective antagonist AH23848 which inhibited short circuit current responses to the TP receptor agonist U-46619 with a pA2 value of 8.44 but was without effect on responses to prostaglandin E2 (PGE2) or the EP selective agonist, sulprostone. 3. In ileal mucosa, the relative potency of agonists differed from that observed in gastric mucosa and was consistent with the view that anion secretion in this region of intestine was controlled by DP and EP2 receptors. 4. These studies suggest that anion secretion in gastric and ileal mucosa is controlled by different prostanoid receptor subtypes and so provide important information for the design of prostanoids which may protect gastric mucosa and that are free from side effects such as diarrhoea.     

A novel 37-Kd adhesive membrane protein from cloned murine bone marrow stromal cells and cloned murine hematopoietic progenitor cells

The adhesion of hematopoietic progenitor cells to bone marrow stromal cells is critical to hematopoiesis and involves multiple effector molecules. Stromal cell molecules that participate in this interaction were sought by analyzing the detergent-soluble membrane proteins of GBI/6 stromal cells that could be adsorbed by intact FDCP-1 progenitor cells. A single-chain protein from GBI/6 cells having an apparent molecular weight of 37 Kd was selectively adsorbed by FDCP-1 cells. This protein, designated p37, could be surface-radiolabeled and thus appeared to be exposed on the cell membrane. An apparently identical 37- Kd protein was expressed by three stromal cell lines, by Swiss 3T3 fibroblastic cells, and by FDCP-1 and FDCP-2 progenitor cells. p37 was selectively adsorbed from membrane lysates by a variety of murine hematopoietic cells, including erythrocytes, but not by human erythrocytes. Binding of p37 to cells was calcium-dependent, and was not affected by inhibitors of the hematopoietic homing receptor or the cell-binding or heparin-binding functions of fibronectin. It is proposed that p37 may be a novel adhesive molecule expressed on the surface of a variety of hematopoietic cells that could participate in both homotypic and heterotypic interactions of stromal and progenitor cells.     

How do clinicians learn to request permission for autopsies?

A postal survey of 434 clinicians at four local hospitals was undertaken in order to identify the methods by which clinicians learn how to request permission for hospital autopsies and to assess the preferred techniques and timing of relevant communication skills training. The majority of 128 responding clinicians had learnt through personal experience with some assistance from senior colleagues and peers. Few clinicians appeared to have learnt through formal training. The preferred methods for the provision of communication skills training were training in small groups (such as seminars or tutorials) and observation of clinicians at work. The most desirable time for the provision of this training was considered to be between the beginning of the final undergraduate year and the end of the pre-registration house officer year. The communication skills training provided within medical education is in need of improvement. More emphasis should be given to clinical-task- or situation-specific applications such as requesting permission for autopsies.