Objectives to direct the training of emergency medicine residents on off-service rotations: Emergency medical services

Emergency Medical Services are an area of special interest in emergency medicine. Many emergency physicians are called upon to direct, train, or manage emergency medical services. Residents training in emergency medicine have a need for a defined curriculum in emergency medical services. Residency training should provide a basic foundation in EMS including on- and off-line medical control, medicolegal aspects, communications, disaster management, and EMS history, structure, and function. The resident must gain experience through on-scene observation, EMT/Paramedic education, medical direction, and quality assurance activities. This paper is one in a continuing series of goals and objectives to direct resident training in off-service rotations. Specific resources, learning objectives, and experiences are suggested.     

The inhibition of platelet aggregation of metastatic H-ras-transformed 10T1/2 fibroblasts with castanospermine, an N-linked glycoprotein processing inhibitor.

A series of T24-H-ras-transformed 10T1/2 fibroblasts with varying metastatic potential was tested for the ability to aggregate platelets. Results indicate that although platelet activation was always detected in the highly metastatic cells, some non-metastatic cells also have the ability to cause platelet aggregation, suggesting that this is a necessary but not sufficient characteristic of the metastatic phenotype. Apyrase, an ADP scavenger, effectively inhibited platelet aggregation by metastatic cells, however, there was no significant increase in ADP secretion or relation to the ability of the tumor cells to activate platelets. Hirudin, a thrombin inhibitor, did not affect aggregation, suggesting that the pathway of activation is thrombin-independent. The glycoprotein processing inhibitor, castanospermine, which reduces glycosidase I activity and metastatic capability, inhibited the ability of metastatic cells to cause platelet aggregation. However, another inhibitor of oligosaccharide processing, swainsonine, which inhibits mannosidase II activity and does not reduce metastasis, had no effect on platelet aggregation. These results show that the integrity of N-linked oligosaccharide structure of glycoproteins is an important feature of the ability of ras-transformed fibroblasts to activate platelets.     

Membrane attack complex of complement in Henoch-Schönlein purpura skin and nephritis

Summary The present study using direct immunofluorescence with monoclonal antibodies to C5b-9 complex-related antigens was undertaken to determine whether complement activation in Henoch-Schönlein purpura (HSP) causes assembly of the membrane attack complex of complement (MAC) in skin and nephritis lesions. The deposition of C5, C6, C7, C8, C9, and C5b-9 neoantigens was noted in the vascular walls of papillary dermis and/or subpapillary dermal plexus of the vessels in 11 out of 15 patients with HSP. Their presence in vessel walls indicates complement activation which leads to terminal complement activation. There were small deposits of S protein at the same sites in three of the 11 skin specimens. Thus, the majority of C5b-9 demonstrated in HSP skin was the cytolytically active C5b-9 complex, MAC. Granular deposits of C5b-9 related antigens without S protein were also found in the capillary walls and mesangium of the glomeruli of two out of four specimens from patients with HSP nephritis; in the other two S protein was colocalized with the deposition of C5b-9. The results of the present study indicate that complement activation leading to generation of MAC may possibly be involved in the pathogenesis of vascular injury in a significantly large number of skin lesions and of HSP nephritis.     

Nodular form of intra-abdominal panniculitis: sonographic features

Sonography of a patient with acute upper abdominal pain demonstrated an encapsulated hyperechoic mass which indented the stomach. Fine-needle biopsy produced atypical cells; the diagnosis of nodular intra-abdominal panniculitis was made at surgery. Sonography probably has a role in the detection and follow-up of this benign lesion.     

Short term responses to soft contact lens corrections for presbyopia

Eleven subjects were each fitted with five different soft contact lens corrections for presbyopia. The correction types were distance contact lenses with lookover spectacles, concentric bifocals, monovi-sion, modified monovision and progressive bifocal contact lenses. Subjects were asked to rate each contact lens correction in terms of distance, intermediate, near and peripheral vision, confidence when walking and climbing stairs, eye-hand co-ordination, performance on work tasks, vision difficulties in bright and dim ambient illumination and the correction most preferred for daily wear. There were few significant differences between ratings for the different corrections. Monovision, modified monovision and the concentric bifocal corrections were the preferred options for daily wear.     

Acute reversible reduction of PGI2 platelet receptors after iloprost infusion in man

Platelet sensitivity to PGI2 and platelet PGI2 receptors were investigated in eight subjects with peripheral artery disease (stage IV according to Fontaine) treated for 14 consecutive days with six hour iv infusion of Iloprost (Schering, FRG) 2 ng/Kg/min. Platelet studies were performed on the 1st, the 2nd, the 7th and the 14th day of therapy, immediately before infusion (between 8.00 and 9.00 a.m.), at the end and 6 and 18 hours (the following morning) after the end of the infusion. Platelet sensitivity to PGI2 was assessed by determining the PGI2 inhibitory dose 50(ID 50) on platelet aggregation induced by 5 μM ADP. PGI2 platelet receptors were investigated by a direct radioligand binding assay.

PGI2 ID 50 after the infusion was significantly higher than that at baseline(p<0.01) and six hours later the baseline sensitivity was restored. After the six hour Iloprost iv infusion a significant reduction in the number of high affinity PGI2 platelet receptor (HAR) was observed (p<0.005) without any change in their affinity for the ligand. Six hours after the end of the infusion the number of the HAR was still significantly reduced (p<0.05). The following morning the receptor number of HAR was restored. The baseline values of PGI2 HAR, when reassessed after seven and fourteen days of treatment, were not significantly different from those recorded on the first day of therapy. These data indicate that the reduction of platelet PGI2 sensitivity following short-term Iloprost infusion is rapidly reversible and is related to a contemporary down-regulation of PGI2 platelet receptors. However the observed decrease of the number of PGI2 receptors, in the absence of any changes in affinity for the ligand, seems unable to explain the reduced biological effects so that the existence of other post-binding alterations could be postulated.     

Prostaglandin synthesis in bovine coronary endothelial cells: comparison with other commonly studied endothelial cells

Comparison of arachidonic acid metabolism by bovine coronary artery endothelial cells, bovine aortic endothelial cells and human umbilical endothelial cells indicated potentially important differences in relative amounts of the different prostaglandins produced. Bovine coronary endothelial cells converted ¹⁴C-arachidonic acid to radioactive 6-keto PGF₁ (the stable metabolite of PGI₂) and to a lesser extent PGE₂. Bovine aortic cells synthesized 6-keto PGF₁ and 6,15-diketo PGF₁ as the major products. PGE₂, 6-keto PGE₁, PGE₂, and PGD₂ were minor metabolites. By comparison, endothelia cells isolated from human umbilical artery or vein formed mainly 6-keto PGF₁ and substantial amounts of PGF₂, PGE₂ and PGD₂. Basal concentrations of 6-keto PGF₁ were two-fold higher in bovine coronary cells than in bovine aortic endothelial cells, but seven-fold less than in endothelial cells cultured from human umbilical vessels. Histamine, bradykinin and thrombin stimulated PGI₂ synthesis in both coronary endothelial cells and human umbilical cells, but only bradykinin stimulated PGI₂ synthesis in bovine aortic cells. This comparative study indicates that endothelial cells vary in the metabolites of arachidonic acid that they produce depending upon the vascular origin of the cells. Also, endothelial cells from different vascular beds respond differently to specific vasoactive agents.     

Erythema multiforme-like and purpuric eruption due to contact allergy to proflavine

Book reviewed in this article:
The Science of Hair Care (Dermatology Series, vol. 7). Ed.: Charles Zviak.
Contact Dermatitis , 3rd edition. Fisher A A.     

Liver tumor promoting ability of corn oil gavage in B6C3F1 male mice

In chronic carcinogenic bioassays, chemicals being tested with low water solubility have been administered via corn oil gavage. The present study examined the effect of chronic corn oil gavage on hepatic tumor formation in the B6C3F1 male mouse. Mice were initiated with diethylnitrosamine (DENA) either at 15 days of age with a single i.p. injection (5 μg/gbw) (protocol 1) or at 4 weeks of age via the drinking water (15 mg/l) for a duration of 3 weeks (protocol 2). At weaning (protocol 1) or 8 weeks of age (protocol 2) initiated and untreated mice were administered either corn oil at a dose of 0.15 ml via gavage (once a day, 5 days/wk) or saline (0.15 ml via gavage, once a day 5 days/wk). All mice were killed at 28 weeks of age and hepatic lesions were quantitated. Only mice exposed to DENA demonstrated hepatic tumors. Mice treated with DENA (at 15 days of age) and corn oil gavage exhibited a significant decrease in the number of hepatic adenomas compared with DENA (at 15 days of age) only treated mice. No difference was noted in the number of hepatic adenomas between mice treated with DENA (at 4 wks of age) and corn oil gavage and mice exposed to DENA (at 4 wks of age) only.     

Emergency department analgesia without narcotics for adults with acute sickle cell pain crisis: Case reports and review of crisis management

Vaso-occlusive crises are one of the most debilitating features of sickle cell disease. There appears to be no standardization of care for adults with pain crisis, and some commonly utilized regimens, such as those employing intramuscular meperidine, are pharmacologically unsound. Parenteral narcotic use may be associated with respiratory compromise acutely and with dependence over the long term, but nonopioid preparations are often unsatisfactory in relieving pain. We have recently enjoyed success with a combination of a parenteral nonsteroidal anti-inflammatory medication and an oral tricyclic antidepressant. We report four representative cases and review the salient points of the management of pain crisis in adult patients in the emergency department.