Virtual intubation training at a remote military site.

To provide medical support to the far forward battlefield, training in advanced medical technologies is essential for military healthcare providers. To meet this challenge, the use of modern video communication technologies and novel medical devices can be implemented. This study demonstrates the combined use of modern video conferencing technology and video laryngoscopy equipment in the virtual laryngoscopy training of deployed military medical personnel.

Extracellular matrix proteins modulate asthmatic airway smooth muscle cell proliferation via an autocrine mechanism.

BACKGROUND: Airway remodeling is a key feature of persistent asthma and includes alterations in the extracellular matrix protein profile around the airway smooth muscle (ASM) and hyperplasia of the ASM. We have previously shown that nonasthmatic ASM cells in culture produce a range of extracellular matrix protein proteins and that asthmatic ASM cells proliferate faster than cells from nonasthmatic patients. OBJECTIVE: In this study, we compared the profile of extracellular matrix proteins produced by nonasthmatic and asthmatic ASM cells. We also examined the influence of these extracellular matrix protein proteins and conditioned medium derived from nonasthmatic or asthmatic ASM cells on the proliferation of nonasthmatic and asthmatic ASM cells. METHODS: Extracellular matrix proteins were measured by ELISA; proliferation of ASM cells was measured by tritiated thymidine incorporation. RESULTS: Production of perlecan and collagen I by the cells from asthmatic patients were significantly increased. In contrast, laminin alpha1 and collagen IV were decreased. Chondroitin sulfate was detectable only in the cells from nonasthmatic patients. Compared with nonasthmatic extracellular matrix proteins, proteins from asthmatic cells enhanced ASM cell proliferation. Conditioned medium from asthmatic ASM cells did not induce greater proliferation compared with conditioned medium from nonasthmatic cells. CONCLUSIONS: The data show that the profile of extracellular matrix protein components is altered in asthmatic cells and that this altered profile and not soluble mediators secreted from the ASM cells has the potential to influence the proliferation of these cells. These changes are likely to contribute to the airway wall remodeling that occurs in asthma.

Effects of base material, plasma proteins and FGF2 on endothelial cell adhesion and growth.

Blood-contacting materials rapidly acquire a coating of plasma proteins which can lead to local platelet activation and thrombus formation. This phenomenon seriously limits the usefulness of small diameter synthetic vascular grafts. One solution to this problem is to pre-seed or encourage in situ colonisation of the material with endothelial cells to maintain a non-thrombogenic surface. We have investigated the effect of contact with plasma and serum on the subsequent ability of human endothelial cells to adhere to model hydrophobic and hydrophylic plastic surfaces, and the effect of surface bound fibroblast growth factor 2 (FGF2) on endothelial cell proliferation. Cell adhesion was mainly dependent on adsorbed fibrinogen or vitronectin, depending on the polymer surface, and correlated with antibody binding to these molecules rather than quantitative surface concentrations. Cell proliferation was directly correlated with surface bound FGF2. Surface binding of the latter was controlled both by the chemical nature of the polymer surface and by the presence of FGF-binding molecules adsorbed on the surface. FGF2 bound specifically to surface-adsorbed fibrinogen, fibronectin and vitronectin as well as to pre-coated heparan sulphate proteoglycan, perlecan. Binding was significantly inhibited by plasma and serum which contained high levels of FGF2 binding proteins. To be effective in supporting endothelialisation of vascular grafts in vivo, surface-bound FGF2 would need to be protected from surface dissociation into the circulating blood.

Secondary prevention following myocardial infarction: evidence from an audit in South Wales that the National Service Framework for coronary heart disease does not address all the issues.

OBJECTIVES: To assess local uptake of treatments for secondary prevention of myocardial infarction and compare with targets in the National Service Framework (NSF) for coronary heart disease. DESIGN: Retrospective audit of case notes with follow up questionnaire at 1 year. SETTING: Teaching hospital and community. PARTICIPANTS: 100 patients alive in December 1998 who had been admitted with an acute myocardial infarction between October 1997 and October 1998. MAIN OUTCOME MEASURES: Local use of aspirin, beta blockers, ACE inhibitors, and statins. RESULTS: Unless contraindicated, discharge aspirin use was 100%, beta blocker use 84%, statin prescription and/or provision of dietetic advice 66% and ACE inhibitors where any heart failure was found was 97%. 1-2 years later total cholesterol remained greater than 5.0 mmol/l in 25% of patients, 24% had stopped beta blockers, and ACE inhibitors remained at a low dose in half of those surveyed. CONCLUSIONS: The NSF for coronary heart disease states that by April 2002 80-90% of patients should be prescribed appropriate secondary prevention. This had nearly been achieved at hospital discharge in 1999. However, follow up indicated problems in ongoing care with cholesterol targets not always being achieved, beta blockers often being stopped, and ACE inhibitors frequently remaining at low doses. Gaining maximum benefit from treatment depends on these secondary targets also being achieved. In these aspects of secondary prevention the NSF represents only an initial step towards effective prevention of coronary heart disease; perhaps the most difficult and expensive steps are yet to be fully realised.

New insights into heparin binding to vitronectin: studies with monoclonal antibodies.

Vitronectin is a plasma glycoprotein that binds to a variety of ligands. There is considerable debate regarding the dependency of these binding interactions upon the conformational status of vitronectin, the role of multimerization and how the binding of different ligands can change vitronectin's conformational state. We have developed a method of capturing vitronectin directly from fresh plasma using solid-phase monoclonal antibodies. Various biotin-labelled secondary monoclonal antibodies were used to quantify the bound vitronectin and to measure its degree of denaturation. Using these tools we demonstrated that one monoclonal antibody partially denatured vitronectin without direct multimerization. Treatment of vitronectin in plasma with soluble heparin produced a similar degree of denaturation. These results led to a proposed adaptation of the unfolding/refolding pathways for chemically denatured vitronectin originally presented by Zhuang and co-workers in 1996 [Zhuang, Blackburn and Peterson (1996) J. Biol. Chem. 271, 14323-14332 and Zhuang, Li, Williams, Wagner, Seiffert and Peterson (1996) J. Biol. Chem. 271, 14333-14343]. The adapted version allows for the production of a more stable partially unfolded intermediate, resulting from the binding of particular ligands. We also demonstrated that the avidity of heparin binding to vitronectin is governed by both the conformational state of the monomer and multimerization of the molecule.

Rate of endothelial expansion is controlled by cell:cell adhesion.

Procedures used to alleviate blood vessel occlusion result in varying degrees of damage to the vascular wall and endothelial denudation. The presence of intact, functioning endothelium is thought to be important in controlling smooth muscle cell growth, and limiting the intimal thickening which results from damage to the vessel wall. Recovery of the endothelium is commonly slow and incomplete, due in part to endothelial lateral cell:cell adhesion, which limits cell migration and proliferation. We have investigated the effect of fibroblast growth factor 2 and vascular/endothelial growth factor on the relationship between the temporal distribution of the junctional adhesion proteins, platelet/endothelial cell adhesion molecule, vascular/endothelial cadherin and plakoglobin, and cellular migration and proliferation in an in vitro model of endothelial expansion. We found that whereas cell:cell junctions were initially disturbed to similar extents by single applications of the growth factors, outward cell migration and proliferation rates were inversely correlated with the speed at which cell:cell junctions were re-established. This occurred very rapidly with vascular/endothelial growth factor treatment and more slowly with fibroblast growth factor-2, resulting in more extensive outward migration and proliferation in response to the latter. Platelet/endothelial cell adhesion molecule and vascular/endothelial cadherin appeared to be associated with cell:cell junctional control of migration and proliferation, while plakoglobin did not contribute. It was concluded that the rate of endothelial expansion in response to growth factors, is limited by the rate of re-association of junctional complexes following initial disruption.

Initial experience and safety in the treatment of chronic total occlusions with fiberoptic guidance technology: optical coherent reflectometry.

Percutaneous treatment of chronic total coronary occlusions has been limited by procedural complications such as vessel injury or perforation. Optimizing visualization in the vessel with optical coherent reflectometry and a forward-looking fiberoptic guidance technology may improve the safety and efficacy of percutaneous treatment of these lesions.

Human endothelial cells grow poorly on vitronectin: role of PAI-1.

The cell adhesive protein vitronectin is a common component of interstitial extracellular matrix and circulates in plasma. It competes effectively with other plasma proteins to adsorb to certain biomaterial surfaces, and is likely to represent an important cell adhesion mediator on the luminal surface of vascular grafts. It is also found associated with certain vascular pathologies. We have shown previously that human endothelial cells grow poorly on a vitronectin surface compared with other extracellular matrix molecules. In this paper we show that endothelial cells seeded on vitronectin and fibronectin produced substantially different profiles of extracellular matrix molecules. The most outstanding difference was in the amount of matrix-localised plasminogen activator-inhibitor-1 which was high on vitronectin and negligible on fibronectin. This was correlated with a small but significant inhibition of cell adhesion to vitronectin compared with fibronectin, and very significant interference with dissociation of cell: extracellular matrix contacts, resulting either from direct inhibition of the proteolytic activity of urokinase, or from interference with urokinase-receptor signaling and consequent focal adhesion turnover. Such interference would inhibit cell proliferation by disabling the cells from loosening their matrix contacts in order to proceed through mitosis. This would seriously compromise endothelial recovery in cases of damage to the vascular wall and placement of stents or grafts, where the presence of surface-adsorbed vitronectin is likely to modulate the tissue response.

Intracoronary autologous blood to seal a coronary perforation.

BACKGROUND: Coronary artery perforation is a rare but serious complication of percutaneous coronary interventions. CASE REPORT: We report on the treatment of a coronary perforation during percutaneous transluminal coronary angioplasty (PTCA) of the left anterior descending (LAD) coronary artery in a patient suffering from post infarction angina complicated by cardiogenic shock. The perforation was treated successfully with intracoronary administration of the patient's own blood. CONCLUSION: This new technique may be used as adjunctive therapy to prolonged balloon inflation, coronary stenting, coronary microcoil and gelfoam embolization in the treatment of severe and hemodynamically compromising perforations.

Specific affinity depletion of cell adhesion molecules and growth factors from serum.

Serum is a common component of most in vitro cell culture media, particularly of primary cells. Studies of cellular responses to particular adhesion molecules or growth factors are often confounded by the presence of these molecules in the serum supplement. We describe a combined affinity protocol for removing vitronectin and fibronectin from serum. This protocol can also be used to purify these molecules. We also describe the removal of growth-promoting elements using heparin-Sepharose. As vitronectin and fibronectin each bind to heparin, these molecules are removed first and the heparin-Sepharose depletion occurs last in the sequence. This protocol provides a detailed step-by-step guide to achieve quantitative depletion of serum in an optimised format, with additional information on pitfalls and problems. It should be of use to people who wish to accurately determine the relationship between cells, extracellular matrix molecules and growth factors.

The production of extracellular matrix proteins by human passively sensitized airway smooth-muscle cells in culture: the effect of beclomethasone.

Airway remodeling is a key feature of persistent asthma. Part of the remodeling process involves the laying down of extracellular matrix (ECM) proteins within the airways. In this study we compared the production of ECM proteins by human airway smooth-muscle (ASM) cells in culture after exposure to 10% serum from an asthmatic individual or 10% serum from a nonasthmatic individual with or without beclomethasone (0.01 to 100 nM). Enzyme-linked immunosorbent assays were done with antibodies to human fibronectin; perlecan; elastin; the laminin beta(1), gamma(1), beta(2), alpha(1) chains; thrombospondin; chondroitin sulfate; collagen types I, III, IV, and V; versican; and decorin. Serum from the asthmatic individual, when compared with that from the nonasthmatic individual, caused a significant increase in the production of fibronectin, perlecan, laminin gamma(1), and chondroitin sulfate. Beclomethasone caused a significant reduction in the number of cells exposed to serum from either the asthmatic or nonasthmatic individual, but did not reverse the increase in ECM protein induced by the former. These results suggest an interaction between the ASM and the allergic process that may alter components of the airway wall in asthma, and that corticosteroids may not prevent the fibrosis induced by resident cells within the airways.

Determinants of use rate of oral rehydration therapy for management of childhood diarrhoea in rural Bangladesh.

In rural Bangladesh, mothers were interviewed to identify factors that determine the use of oral rehydration therapy (ORT) for management of diarrhoea in children aged less than 5 years. The point prevalence of diarrhoea among 1,600 children was 11.6%, with 46% having acute watery diarrhoea. The overall ORT-use rate was 29%; only 17% of the cases used it adequately. Common reasons for not using ORS included misperception about diarrhoea and age of patients. Other reasons included incorrect assessments, severity, and difficulties with the administration of oral rehydration solutions. Promotion of ORT can be effected by improving the level of understanding of mothers with regard to assessment of severity, early initiation of treatment regardless of age, sex, type of diarrhoea, breast-feeding, and nutrition status.

Low density lipoproteins in human plasma make vascular smooth muscle cells resistant to growth inhibition by heparin.

OBJECTIVE: Vascular smooth muscle cell hyperplasia plays a role in atherosclerosis and restenosis. While heparin has shown promise as an inhibitor of smooth muscle cell proliferation in vitro and in some animal models, it has failed to reduce restenosis in clinical trials. We have previously shown that human smooth muscle cells grown in the presence of human serum are heparin resistant, whereas in the presence of bovine serum they are heparin sensitive. In this report, we demonstrate that the heparin resistance factor is present in human plasma as well as serum, and characterise it further. METHODS: Human vascular smooth muscle cells were cultured as explants from the media of redundant adult internal mammary or umbilical cord arteries. They were tested for sensitivity to heparin at 100 microg/ml in the growth medium, in the presence of foetal bovine serum, human-plasma-derived serum, human whole blood serum, or fractions derived from these. RESULTS: In the presence of foetal bovine serum, heparin inhibited cell proliferation, while human-plasma-derived or whole blood sera conveyed heparin resistance. This activity was contained within the fraction of plasma/serum which bound to heparin Sepharose, and the sub-fraction which was retained by a membrane filter of molecular weight cut off of 100000. All the heparin resistance in this latter fraction was supplied by lipoproteins. LDL prepared directly from human plasma conveyed similar heparin resistance to the lipoproteins from the above sub-fraction. CONCLUSION: LDL in human plasma/serum conveys resistance to the anti-proliferative effects of heparin upon vascular smooth muscle cells. This activity may interfere with potential therapeutic effects of heparin as an anti-restenosis agent.

B-Lynch suture for postpartum hemorrhage.

BACKGROUND: Postpartum hemorrhage is a major contributor to maternal morbidity and mortality. Numerous medical and surgical therapies have been used, but none has been uniformly successful. CASE: Two women with postpartum hemorrhage due to uterine atony after cesarean for twins are presented. Neither responded to medical management. In the first subject, O'Leary uterine artery ligation and utero-ovarian branch ligations were done without benefit. The B-Lynch suture immediately sustained correction of hemorrhage in both subjects. Magnetic resonance imaging and hysterosalpingogram after the first case showed no uterine defects. CONCLUSION: The B-Lynch suture might be a valuable addition to the surgical treatment of postpartum hemorrhage due to uterine atony.