Search PubMed⌕ Search

Biomedical subjects

L Bell

Publications and source records attributed to L Bell.

At least 37 records · Page 2Linked to original sources
PubMed1995

Why the NHS should abandon the search for the universal outcome measure.

This paper considers the use of outcome measures in the British National Health Service (NHS). Measuring outcomes is a major conceptual and practical problem. Many different measures are currently available yet no consensus has been reached on which should be preferred over others, or about which should take priority when they conflict. Some currently used measures are described, the relationship between these measures and the measured activities are discussed, and fundamental problems with both the measures and their use are revealed. It is shown that however assiduous the search, the 'perfect' outcome measure will always remain elusive.

Commerce↗
PubMed1995

Progress in a Moscow children's burn unit: a joint Russian-American collaboration.

A joint Russian-American paediatric burn programme involving Childrens Hospital No. 9 in Moscow and Project HOPE in Millwood, Virginia emerged from the efforts of burn professionals from both countries in caring for a group of children seriously burned as a result of the train-pipeline catastrophe that occurred in June 1989 in the Ural Mountains. This paper describes the burn unit and its activities during the years 1985-93 and includes: (1) a general description of the physical and administrative structure of the unit; (2) the demography of burn admissions; (3) clinical activities; (4) a comparison of the clinical results of the years before the institution of the combined programme (1985-89) with those achieved during the first 4 years of the combined collaboration (1990-93). Among the important changes that have occurred since the onset of the combined programme are: (1) overall reduction in the crude burn mortality rate; (2) decrease in burn deaths in all burn size groups; (3) dramatic reduction in the length of stay of children with the deepest burns; (4) marked improvement in the take of skin grafts applied to burn wounds and an almost total elimination of complete skin graft failures.

Adolescent↗
PubMed1995

Anterior hippocampal volume reductions predict frontal lobe dysfunction in first episode schizophrenia.

This study examined relations of mesiotemporal lobe tissue volumes with neuropsychological (NP) functions in a sample of patients with first episode schizophrenia. Three contiguous compartments of the mesiotemporal lobe were measured on magnetic resonance images, comprising primarily amygdaloid, anterior hippocampal, and posterior hippocampal tissue volumes. NP measures were derived from a comprehensive battery. Decreased volume selectively in the anterior hippocampal formation was associated with lower scores on measures of executive and motor functions usually considered sensitive to the integrity of frontal lobe systems. Measures of other NP functions, and global intellectual ability, were not related to mesiotemporal volumes. The findings that morphologic abnormalities in the mesiotemporal lobe are associated with impairment of frontal lobe functions point to a defect in an integrated functional system that includes both frontal and mesiotemporal components. The findings are consistent with the hypothesis that neurodevelopmental defects affecting the morphology of the anterior hippocampal formation may be manifest later in life as impairments in fronto-limbic control. .

Acute Disease↗
PubMed1995

A randomized, controlled trial of the efficacy of a heparin and vancomycin solution in preventing central venous catheter infections in children.

OBJECTIVE: To determine whether adding vancomycin to central venous catheter (CVC) flush solution would significantly reduce the incidence of bacteremia attributable to luminal colonization with vancomycin-susceptible organisms. STUDY DESIGN: Fifty-five children with cancer and eight children given total parenteral nutrition by the surgery or nutrition support services were randomly assigned to receive a heparin CVC flush solution (n = 31) or a heparin-vancomycin CVC flush solution (n = 32). RESULTS: During 9158 catheter days, 6.5% of the patients in the heparin group and 15.6% of the patients in the heparin-vancomycin group had bacteremia attributable to luminal colonization with vancomycin-susceptible organisms (p = 0.43). The mean rates of bacteremia attributable to luminal colonization with vancomycin-susceptible organisms were 0.6/1000 catheter days in the heparin group and 1.4/1000 catheter days in the heparin-vancomycin group (p = 0.25). There was no significant difference between the groups when the time to the first episode of bacteremia attributable to luminal colonization with a vancomycin-susceptible organism was compared by means of Kaplan-Meier survival estimates. Streptococcus viridans infection was not attributable to luminal colonization. CONCLUSION: The addition of vancomycin to heparin CVC flush solution did not reduce bacteremia with vancomycin-susceptible organisms. Bacteremia with Streptococcus viridans was not related to the use of a CVC.

Adolescent↗
PubMed1995

Involving patients in the provision of community care: a change in philosophy.

The National Health Service (NHS) has many different kinds of professionals and managers working underneath its large umbrella: non-clinical managers administer the work of health-care professionals, who in turn are concerned with the management of patients' treatments. Delivery of health-care services involves the managers and professionals working together to achieve a service that is good for, and acceptable to, patients. A change in the philosophy of the NHS is indicated by the growing acceptance, by both managers and professionals, of the necessity to elicit the views of patients (i.e. the expectations and perceptions of service users) and to incorporate these views into the planning and implementation of services. Discusses one such attempt to elicit the perceptions of service users, and reports on the preliminary findings of a patient-centred audit which has been undertaken in Southend Community Care Services NHS Trust. Discusses the effects that the audit has had on the chiropody services in Southend, for both non-clinical managers and health-care professionals, in order to highlight the usefulness of the approach.

Community Health Services↗
PubMed1994

Steel factor affects SCL expression during normal erythroid differentiation.

Steel factor is one of the growth factors that controls the proliferation and differentiation of hematopoietic cells and SCL, also known as Tcl-5 or Tal-1, is a transcription factor involved in erythropoiesis. In this report, we studied the role of SCL in the proliferation of human peripheral blood burst-forming unit-erythroid (BFU-E) and the effects of Steel factor on SCL expression in proliferating erythroid cells. BFU-E-derived colonies increase progressively in size, as determined by cell number, from day 7 to day 14 of culture, with the greatest increase in colony size (10-fold expansion) occurring between day 7 and day 10. SCL protein levels in BFU-E-derived cells were highest in day 7 cells and decreased progressively from day 7 to day 14 of culture, suggesting an association of SCL with erythroid proliferation. In contrast, SCL mRNA levels did not decrease significantly between day 7 and day 14 cells, suggesting that posttranscriptional mechanisms are largely responsible for the decrease in SCL protein observed. The role of SCL in Steel factor-induced erythroid proliferation was then examined. In BFU-E-derived colonies cultured with Steel factor, colony size was significantly increased compared to control. In day 7 and day 10 erythroid precursors cultured with Steel factor, SCL protein was increased significantly compared to control. The increase in SCL protein levels in early erythroid precursors stimulated with Steel factor suggests one mechanism through which Steel factor may enhance normal erythroid proliferation. SCL mRNA levels assessed by Northern blot in day 7 cells did not increase significantly in response to Steel factor stimulation, suggesting that posttranscriptional mechanisms may also be important in the increase in SCL protein observed in response to Steel.

Base Sequence↗
PubMed1994

Who is the NHS for?

The immediate, common sense answer to the question, "Who is the NHS for?" would obviously be, "The patients who use it". This may well be the fundamental purpose of the NHS, yet it would appear that differing views of how this is to be achieved contribute to a misreading between stakeholders of each others' remit. The different positions taken by the two most important NHS stakeholders, the professional clinicians and the administrative managers, affect their definitions of, and therefore their attitudes to their own contribution to the purpose of the NHS. Suggests that before priorities in health care can be considered and discussed, let along be set, consensual agreement needs to be reached concerning the views of professional clinicians and managers of ways of achieving their vision of who the NHS is for.

Administrative Personnel↗
PubMed1993

Photoinhibition of smooth muscle cell migration: potential therapy for restenosis.

Evidence from animal, autopsy, and atherectomy studies demonstrates that migration and proliferation of smooth muscle cells of medial origin result in neointima formation and decreased luminal cross-sectional area. The purpose of this study was to evaluate whether low energy light irradiation can inhibit smooth muscle cell migration and therefore potentially reduce the degree of neointima formation and the incidence of restenosis. The migration kinetics of bovine aortic smooth muscle cell monolayers were examined using a fence assay. The effect on smooth muscle cell migration of irradiation with monochromatic light at wave-lengths ranging from 400 to 700 nm was compared to the migration of cells irradiated with broadband white light or maintained in the dark. Wavelength specific photoinhibition of smooth muscle cell migration was observed; 594-600 nm light reproducibly inhibited migration by 12-29% (P < 0.05). Migration rate was significantly reduced following daily radiant exposures of 1.0 J/cm2 as well as following a single radiant exposure of 0.09 or 0.9 J/cm2. The decrease in migration was not associated with any change in cell proliferation or [3H] thymidine incorporation. We conclude that 594-600 nm light inhibits smooth muscle cell migration in vitro and may potentially be used in vivo to decrease fibrointimal thickening following arterial injury. This application of photoinhibition may be useful in retarding restenosis following angioplasty.

Animals↗
PubMed1993

Devising a multidisciplinary audit tool.

Discusses the audit processes in health care from the existing perspectives and argues the need to extend the current unidimensional approaches which include medical, clinical and managerial quality. Argues that one way of expanding these approaches is to develop an audit instrument based on the views of service users. The implementation of audit has been a process with regional variations, which have created centres of excellence and centres where there is very little happening. Considers elements that are involved in devising an audit tool which is based on customers' perceptions of service quality, and reports on an empirical study which is still in progress and which aims to develop a tool which is effective, efficient and based on patients' views.

Aged↗
PubMed1993

Fibronectin expression correlates with U937 cell adhesion to migrating bovine aortic endothelial cells in vitro.

A blood vessel's response to denudation injury will determine its final luminal diameter as well as its function. The synthesis, deposition, and remodeling of extracellular matrix components and migration by vascular endothelial cells are major factors in determining luminal diameter, cellular proliferative and migratory responses, and mononuclear cell adhesion at sites of injury. Previously, we have shown that after in vivo and in vitro denudation injury, endothelial cell migration is dramatically influenced by the amount of fibronectin synthesized and deposited by the responding endothelial cell population. The aim of this study was to elucidate the roles of fibronectin in modulating mononuclear cell adhesion to the endothelial cell population during in vitro migration. In this report we demonstrate that U937 cell binding to the migrating fronts of endothelial cell monolayers is modulated by the amount of fibronectin synthesized and deposited by the endothelial cells. Agents which increase fibronectin deposition, such as transforming growth factor-beta 1, elicit greater U937 cell adhesion. Manipulations that decrease fibronectin deposition, such as transfection and overexpression of pp60c-src proto-oncogene in endothelial cells, reduce U937 cell adhesion. These results suggest that changes in endothelial cell extracellular matrix synthesis and deposition modulate, in part, the adhesive properties of the vessel wall after injury. In turn, the intensity and duration of mononuclear cell adhesion at sites of vessel wall injury determines, in part, the vessel wall response.

Animals↗
PubMed1992

An endosomal-lysosomal pathway for degradation of amyloid precursor protein.

We previously reported evidence for a lysosomal degradative pathway for APP and C-terminal fragments thereof, based on Western and immunocytochemical analysis of drug-treated cells. Here, we verify the existence of a lysosomal degradative pathway for APP using pulse chase immunoprecipitation analysis of drug-treated cells and fibroblasts with and without a known lysosomal hydrolase targeting defect. The results are consistent with the hypothesis that part or all of the beta-protein domain of APP is normally degraded by lysosomes. A mechanism for beta-protein deposition based on this data is hypothesized.

Amyloid beta-Protein Precursor↗
PubMed1992

Modulation of vascular cell behavior by transforming growth factors beta.

The vascular cell responses to the type 1, 2, and 3 isoforms of transforming growth factor-beta (TGF-beta 1, TGF-beta 2, TGF-beta 3) were studied using bovine aortic endothelial (BAECs) and smooth muscle cells (BASMC3) as well as rat epididymal fat pad microvascular endothelia (RFCs). Three distinct bioassays indicated that TGF-beta elicits results that do not differ significantly from those of the TGF-beta 1 isoform in all three cell populations. These assays are: inhibition of proliferation, cell migration, and neovascularization. By contrast the cellular responses to TGF-beta 1 and TGF-beta 3 differed from those to TGF-beta 2. Three distinct receptor assays revealed the presence of type I and type II TGF-beta 1 cell surface binding proteins on BAECs, BASMCs, and RFCs. Experimentation to decipher cell surface binding by the different isoforms revealed that iodinated TGF-beta 1 bound to the surface of all three vascular cell types can be competed off in similar fashion by either TGF-beta 1 or TGF-beta 3; however, competition with TGF-beta 2 produced unique binding profiles dependent on the cell type examined. The ratios of type I to type II TGF-beta receptors in these three vascular cell types vary from 1:1 in BAECs to 1.5:1 in RFCs to 3:1 in BASMCs and can be correlated with the differences noted in cellular responses to TGF-beta 1 and TGF-beta 2 in proliferation, migration, and in vitro angiogenic assays.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Autocrine angiotensin system regulation of bovine aortic endothelial cell migration and plasminogen activator involves modulation of proto-oncogene pp60c-src expression.

Rapid endothelial cell migration and inhibition of thrombosis are critical for the resolution of denudation injuries to the vessel wall. Inhibition of the endothelial cell autocrine angiotensin system, with either the angiotensin-converting enzyme inhibitor lisinopril or the angiotensin II receptor antagonist sar1, ile8-angiotensin II, leads to increased endothelial cell migration and urokinase-like plasminogen activator (u-PA) activity (Bell, L., and J. A. Madri. 1990. Am. J. Pathol. 137:7-12). Inhibition of the autocrine angiotensin system with the converting-enzyme inhibitor or the receptor antagonist also leads to increased expression of the proto-oncogene c-src: pp60c-src mRNA increased 7-11-fold, c-src protein 3-fold, and c-src kinase activity 2-3-fold. Endothelial cell expression of c-src was constitutively elevated after stable infection with a retroviral vector containing the c-src coding sequence. Constitutively increased c-src kinase activity reconstituted the increases in migration and u-PA observed with angiotensin system interruption. Antisera to bovine u-PA blocked the increase in migration associated with increased c-src expression. These data suggest that increases in endothelial cell migration and plasminogen activator after angiotensin system inhibition are at least partially pp60c-src mediated. Elevated c-src expression with angiotensin system inhibition may act to enhance intimal wound closure and to reduce luminal thrombogenicity in vivo.

1-Sarcosine-8-Isoleucine Angiotensin II↗
PubMed1992

Cholesterol-lowering effects of calcium carbonate in patients with mild to moderate hypercholesterolemia.

BACKGROUND: In recent years, several authors have noted that oral calcium treatment was associated with a reduction in serum cholesterol level. METHODS: Calcium carbonate was examined for its ability to lower serum cholesterol levels in hypercholesterolemic patients. Fifty-six patients with mild to moderate hypercholesterolemia were examined in this randomized, double-blind, placebo-controlled crossover study. Patients were treated with a low-fat, low-cholesterol diet targeted at the American Heart Association Step-1 diet for 8 weeks before and while receiving placebo or calcium carbonate (9.98 mmol [400 mg] of elemental calcium) three times daily with meals for 6 weeks. Patients were then crossed over to the alternate treatment for an additional 6-week period. RESULTS: Compared with placebo, calcium carbonate achieved a 4.4% reduction in the low-density lipoprotein cholesterol level, and a 4.1% increase in the high-density lipoprotein cholesterol level. The ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol significantly decreased by 6.5% with calcium carbonate treatment. Calcium carbonate treatment did not significantly affect blood pressure or serum levels of triglycerides, lipoprotein Apo B, or calcium. Relative urinary saturation ratios of calcium oxalate levels were unchanged during calcium carbonate therapy. Compliance with diet and treatment was excellent and no significant adverse effects were noted. CONCLUSIONS: Thus, calcium carbonate was a modestly effective and well-tolerated adjunct to diet in the management of mild to moderate hypercholesterolemia in this clinical study.

Adult↗
PubMed1991

Role of pertussis toxin-sensitive guanosine triphosphate-binding proteins in the response of erythroblasts to erythropoietin.

Human progenitor-derived erythroblasts have been recently shown to respond to erythropoietin (Epo) with an increase in intracellular free calcium concentration [Cac]. To explore the role of guanosine triphosphate (GTP)-binding proteins in mediating the rise in [Cac], single day 10 erythroid burst forming unit (BFU-E)-derived erythroblasts loaded with Fura-2 were pretreated with pertussis toxin (PT), stimulated with Epo, and [Cac] measured over 18 minutes with fluorescence microscopy coupled to digital video imaging. The [Cac] increase in day 10 erythroblasts stimulated with Epo was blocked by pretreatment with PT in a dose-dependent manner but not by heat-inactivated PT. These observations provided strong evidence that a PT-sensitive GTP-binding protein is involved. To further characterize the GTP-binding protein, day 10 erythroblast membrane preparations were solubilized, electrophoresed, and immunoblotted with antibodies specific for the known PT-sensitive G-protein subunits: the three subtypes of Gia (1,2, and 3) and Goa, Gia1 or Gia3 and Gia2 were identified but no Goa was found. To examine the influence of Epo on adenylate cyclase activity, day 10 erythroblasts were initially treated with Epo, isolated membrane preparations made, and cyclic adenosine monophosphate (cAMP) production by adenylate cyclase in membrane preparations in the presence of theophylline measured. Epo did not inhibit but significantly stimulated adenylate cyclase activity. However, the mechanism of increase of [Cac] appears to be independent of adenylate cyclase stimulation because treatment of erythroblasts with the cell-permeant dibutyryl cAMP failed to increase [Cac]. In summary, pertussis toxin blocks the increase in [Cac] in erythroblasts after Epo stimulation suggesting that this response is mediated through a pertussis toxin-sensitive GTP-binding protein. Candidate PT-sensitive GTP-binding proteins identified on day 10 erythroblasts were Gia 1, 2, or 3, but not Goa.

Adenylate Cyclase Toxin↗
PubMed1991

Effects of soluble factors and extracellular matrix components on vascular cell behavior in vitro and in vivo: models of de-endothelialization and repair.

Vessel walls are comprised of several different cell populations residing in and on complex extracellular matrices. Each of the vascular cell types has diverse and sometimes unique functions and morphologies, and each has roles in repair processes following injury. Large vessel endothelial cells are known to respond to denudation injury by sheet migration and proliferation. This is in contrast to the migration through soft tissues with tube formation and subsequent lumen formation exhibited by microvascular endothelial cells in response to injury. Vascular smooth muscle cells of larger vessels respond to injury by migration from the arterial media into the intima, proliferation, and matrix biosynthesis, ultimately causing intimal thickening. Both these cell types exhibit "dysfunctional" phenotypes during their responses to injury. Microvascular cell responses to injury, while extremely variable, are less well documented. Specifically, responses to injury by microvascular endothelial vascular cells appear to be modulated, in part, by the composition and organization of the surrounding matrix as well as by the various soluble factors and cytokines found at sites of injury, suggesting that the extracellular matrix and soluble factors modulate each other's effects on local vascular cell populations following injury.

Animals↗
PubMed1991

Asynchronous development of the rat colon.

Mucosal ridge and fold formation, apoptosis and the occurrence of secondary lumina within the epithelium are morphological features associated with the development of the colon. These processes, however, do not occur synchronously in the various segments of the colon. In the caecum and ascending colon of the rat, fold formation, apoptosis and secondary lumina result in the development of villi by day 22 after conception, and by postnatal day 3 in the transverse colon. These villi persist in the rat colon until approximately postnatal day 10. The presence of colonic villi may be correlated with the increased food intake and fluid absorption during this early postnatal period. Villus formation does not take place in the developing descending colon.

Animals↗