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Biomedical subjects

J Bentley

Publications and source records attributed to J Bentley.

At least 19 recordsLinked to original sources
PubMed2001

Glucose transport regulation by p210 Bcr-Abl in a chronic myeloid leukaemia model.

The regulation of nutrient transport by both cytokines and oncogenes has been linked to haemopoietic cell survival. In this study, we found that activation of Bcr--Abl protein tyrosine kinase was associated with the stimulation of glucose transport in the multipotent haemopoietic cell line FDCP-mix, a cell model for chronic-phase chronic myeloid leukaemia (CML). Bcr--Abl upregulation of glucose transport was mediated by phosphatidylinositol-3-kinase. The observation that Bcr--Abl can regulate glucose transport in a CML cell model raises the possibility that glucose transport regulation may have a role to play in the aberrant survival of stem cells in the chronic phase of CML.

Biological Transport↗
PubMed2001

Pulmonary arterial dilation by inhaled NO: arterial diameter, NO concentration relationship.

The objective of this study was to determine the nitric oxide (NO) concentration and vessel diameter dependence of the pulmonary arterial dilation induced by inhaled NO. Isolated dog lung lobes were situated between a microfocal X-ray source and X-ray detector and perfused with either blood or plasma. Boluses of radiopaque contrast medium were injected into the lobar artery under control conditions, when the pulmonary arteries were constricted by infusion of serotonin and when the serotonin infusion was accompanied by inhalation of from 30 to 960 parts/million NO. Arterial diameter measurements were obtained from X-ray images of vessels having control diameters in the 300- to 3,400-microm range. Serotonin constricted the vessels throughout the size range studied, with an average decrease in diameter of approximately 20%. The fractional reversal of the serotonin-induced constriction by inhaled NO was directly proportional to inhaled NO concentration, inversely proportional to vessel size, and greater with plasma than with blood perfusion in vessels as large as 3 mm in diameter. The latter indicates that intravascular hemoglobin affected the bronchoalveolar-to-arterial luminal NO concentration gradient in fairly large pulmonary arteries. The data provide information regarding pulmonary arterial smooth muscle accessibility to intrapulmonary gas that should be useful as part of the database for modeling the communication between intrapulmonary gas and pulmonary arterial smooth muscle cells in future studies.

Administration, Inhalation↗
PubMed2001

Promoting patient partnership in wound care.

Involving patients in their care is a key component of the NHS plan and clinical governance (Department of Health, 1999a). Involvement is enhanced through nurse-patient relationships which are based on partnership in which the patient's viewpoint is given equal weight to that of the practitioner. In the management of wounds, this may be complex due to conflict between clinically effective treatment and a patient's wish. High quality care relies on a holistic assessment of the patient and a negotiated care plan which is implemented and evaluated in order to judge the effectiveness of care.

Aged↗
PubMed2001

Preventing unnecessary suffering: an audit of a leg ulcer clinic.

Unnecessary patient suffering and increased costs in leg ulcer care were reported in an Effective Health Care bulletin (NHS Centre for Reviews and Dissemination (NHSCRD), 1997). Follow-up assessment of patients with a history of venous ulceration has beneficial effects for patients' quality of life, and for effective and efficient management of resources for community nurses. This article describes the process of implementing evidence-based practice in a leg ulcer clinic in South London within existing resources, which resulted in the successful prevention of leg ulcer recurrence.

Chronic Disease↗
PubMed2001

Assess, negotiate, treat: community prescribing for chronic wounds.

The cost of prescribing wound-care products in general practice in 1999 exceeded 95 million (Department of Health (DoH), 1999a). However, there is a lack of randomized controlled trials to assess the effectiveness of wound-care products (National Prescribing Centre, 1999a) and there is evidence that non-effective treatments are being prescribed (DoH, 1999a). Use of the prescribing pyramid, as taught during nurse prescribing courses, may help community nurses justify their decisions and assess their wound-care practices. Wounds commonly encountered in the community include pressure sores, leg ulcers, fungating wounds and cavity wounds. The ideal choice of product is one that allows moist wound healing, is cost effective, clinically effective and acceptable to the patient.

Bandages↗
PubMed2001

Defined conundrum.

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Economics, Hospital↗
PubMed2000

Valence state mapping of cobalt and manganese using near-edge fine structures

The properties of transition metal oxides are related to the presence of elements with mixed valences. The spectroscopy analysis of the valence states is feasible experimentally, but a spatial mapping of valence states of transition metal elements is a challenge to existing microscopy techniques. In this paper, with the use of valence state information provided by the white lines and near-edge fine structures observed using the electron energy-loss spectroscopy (EELS) in a transmission electron microscope (TEM), a novel experimental approach is demonstrated to map the valence state distributions of Mn and Co using the ratio of white lines in the energy-filtered TEM. The valence state map is almost independent of specimen thickness in the thickness range adequate for quantitative EELS microanalysis. An optimum spatial resolution of approximately 2 nm has been achieved for a two-phase Co oxides.

Journal Article↗
PubMed2000

A health visitor for older people in an accident and emergency department.

Published studies indicate that older people have special needs on discharge from accident and emergency (A&E) departments that are not always fully met. The literature reflects that although a significant proportion of older people have a decrease in functional independence and an increased need for services following discharge from A&E, social and functional assessment by A&E staff can be inadequate, as can the arrangement of follow-up community services. As part of a wider study into the organization of care for older people in A&E, a health visitor for older people was funded to work part-time in the A&E department of a large NHS Trust. The health visitor identified potential clients through reviewing the A&E documentation of patients aged 75 years or over discharged directly from A&E. Telephone calls or home visits were used to follow up those individuals deemed to be vulnerable by the health visitor. Interventions included health education, referral to other agencies and patient or family counselling. None of the clients followed up by the health visitor (n = 212) had been referred by A&E to a specialist in gerontology, which suggests that these clients would otherwise not have received the potential benefit of specialist intervention. The pilot study described here highlights a number of practical issues in relation to the health visitor post for older people in A&E, including the importance of dedicated office space and access to a telephone. Data collected during the study, plus the positive evaluation of the role by a small group of A&E staff confirm the claims made in other studies (e.g. Runciman et al, 1996) that health visitors for older people may be of value in meeting the post-discharge needs of these people.

Accidental Falls↗
PubMed1998

The end of sharing?

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Cultural Diversity↗
PubMed1998

The 5-hydroxytryptamine6 receptor-selective radioligand [3H]Ro 63-0563 labels 5-hydroxytryptamine receptor binding sites in rat and porcine striatum.

Ro 63-0563 [4-amino-N-(2,6 bis-methylamino-pyridin-4-yl)-benzene sulfonamide] is a high affinity 5-hydroxytryptamine6 (HT6) receptor antagonist with more than 100-fold selectivity for the 5-HT6 receptor compared with 69 other receptors and binding sites. The present study describes the properties of [3H]Ro 63-0563, the first selective 5-HT6 receptor radioligand. Specific binding of [3H]Ro 63-0563 (nonspecific binding defined in the presence of 10 microM methiothepin) to recombinant rat and human 5-HT6 receptors was saturable, rapid, and reversible with equilibrium dissociation constants (Kd) of 6.8 nM and 4.96 nM, respectively. The pharmacological profile of the rat 5-HT6 receptor labeled with [3H]Ro 63-0563 (methiothepin > D-lysergic acid diethylamide > clozapine approximately Ro 63-0563 > lisuride > ergotamine approximately Ro 04-6790 > 5-HT > amitriptyline approximately metergoline approximately mianserin approximately ritanserin > methysergide > mesulergine) was similar to that obtained by using either [3H]D-lysergic acide diethylamide or [3H]5-HT as radioligand. In equilibrium binding studies with rat striatal membranes, [3H]Ro 63-0563 labeled a single binding site with Kd and Bmax values of 11. 7 nM and 175 fmol/mg protein, respectively. In porcine striatal membranes, [3H]Ro 63-0563 also labeled a single binding site with Kd and Bmax values of 8.0 nM and 130 fmol/mg protein, respectively. The affinities of 14 5-HT6 receptor ligands at this binding site were similar to those found for the recombinant rat and human 5-HT6 receptor, which suggested the presence of 5-HT6 receptors in porcine striatum.

Aminopyridines↗
PubMed1998

Memories of a WHO expert in midwifery.

Much of the health infrastructure we now take for granted is the result of determined efforts made in the 1960s and 1970s. The objective was relatively clear: to help build up strong national health systems. But to do that an uncommon amount of energy and imagination was needed.

Anecdotes as Topic↗
PubMed1997

The human KB multidrug-resistant cell line KB-C1 is hypersensitive to inhibitors of glycosylation.

We have previously shown that the hypersensitivity of KB MDR cells to 2-deoxy-D-glucose is associated with diminished plasma membrane GLUT-1 levels compared with parental, non-MDR cells. Here we report that MDR cells are hypersensitive to the N-linked glycosylation inhibitor tunicamycin, which induces partial inhibition of GLUT-1 glycosylation and diminishes GLUT-1-mediated transport. The effect of tunicamycin, which also enhances the hypersensitivity of MDR cells to 2-deoxy-D-glucose, could not be attributed to alterations in P-glycoprotein activity. The use of agents that act synergistically to diminish the level and activity of GLUT-1 in MDR cells may be of clinical potential.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Relationships between bacterial drug resistance pumps and other transport proteins.

We have used three reference sequences representative of bacterial drug resistance pumps and sugar transport proteins to collect the 91 most closely related sequences from a composite, nonredundant protein sequence database. Having eliminated certain very close relatives, the remainder were subjected to analysis and alignment by using two different similarity matrices: one of these was a matrix based on structural conservation of amino acid residues in proteins of known conformation and the other was based on the more familiar mutational matrix. Unrooted similarity trees for these proteins were constructed for each matrix and compared. A systematic analysis of the differences between these trees was undertaken and the sequences were analyzed for the presence or absence of certain sequence motifs. The results show that the clades created by the two methods are broadly comparable but that there are some clusters of sequences that are significantly different. Further analysis confirmed that (1) the sequences collected by this objective method are all known or putative 12-helix (in some cases reported as 14-helix) transmembrane proteins, (2) there is evidence for few cases of an origin based on gene duplication, (3) the bacterial drug resistance pumps are distributed in more than one clade and cannot be regarded as a definitive subset of these proteins, and that (4) the diversity is such that there is no evidence of a single ancestral protein. The possible extension of the methods to other cases of divergent protein sequences is discussed.

Amino Acid Sequence↗
PubMed1996

Child-related services in general accident and emergency departments.

A survey undertaken by the British Paediatric Association (BPA) in 1985 highlighted deficits in the services and facilities provided by accident and emergency (A & E) departments for children. Following this survey several documents were published by professional and voluntary organizations advising on the care of children in such departments. The current study, conducted as part of a larger project, involved the distribution of questionnaires (by post) to the nursing managers of a total of 193 general A & E departments in England, Scotland and Wales. The overall response rate of 87% was very encouraging. This article explores the nurse managers' perceptions of the personnel required to meet the needs of children in A & E. It looks especially at the role of Registered Sick Children's Nurses (RSCNs). The findings suggest that the need for RSCNs is not always accepted. RSCNs seem to be employed in some departments as a token presence. Factors seen by nurse managers as limiting their recruitment are discussed. According to the responses given, the role of the RSCNs currently employed in A & E, varies considerably. The findings give some insight into the degree to which current staffing for children in A & E meet the guidelines published by professional and voluntary bodies.

Accidents↗
PubMed1996

2-deoxy-D-glucose toxicity and transport in human multidrug-resistant KB carcinoma cell lines.

It is shown that a series of colchicine-selected multidrug-resistant (MDR) human KB carcinoma cell lines displayed increasing 2-deoxy-D-glucose collateral sensitivity, which correlated with increasing multidrug resistance. The relative resistance of MDR cell lines to 2-deoxy-D-glucose was reduced to 0.73 (KB-8-5), 0.3 (KB-8-5-11) and 0.2 (KB-C1) when compared with parental KB-3-1 (1.0). 2-Deoxy-D-glucose accumulation was found to be reduced in the MDR cell lines in a manner that correlated with 2-deoxy-D-glucose collateral sensitivity. At 30 min 2-deoxy-D-glucose accumulation was reduced to 0.61 (KB-8-5), 0.41 (KB-8-5-11) and 0.22 (KB-C1) relative to KB-3-1 uptake (1.0). The efflux of 2-deoxy-D-glucose was not significantly different between resistant and sensitive cell lines. Analysis of 2-deoxy-D-glucose uptake kinetics, by initial rate measurements, showed alterations in K(t) and J(max) for MDR when compared with KB-3-l cells. The levels of GLUT-1 facilitative transporter were found to be reduced significantly in the MDR cell lines in total cell homogenate and plasma membrane fractions by using Western blot analysis. Changes in the plasma membrane level of GLUT-1 correlated with 2-deoxy-D-glucose toxicity and uptake for MDR cell lines, where relative GLUT-i levels were reduced to 0.71 (KB-8-5), 0.43 (KB-8-5-1 1) and 0.27 (KB-Cl) relative to KB-31(1.0). It is concluded that the response of human KB MDR cells to 2-deoxy-D-glucose involved alterations in the level and activity of the facilitative glucose transporter, GLUT-1, in a manner that is associated with the degree of multidrug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗