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Biomedical subjects

J Furness

Publications and source records attributed to J Furness.

At least 19 recordsLinked to original sources

Randomized comparative trial between percutaneous longlines and peripheral cannulae in the delivery of neonatal parenteral nutrition.

UNLABELLED: Percutaneously inserted central venous catheters (CVCs) are frequently used for parenteral nutrition (PN) in neonates. Catheter-related sepsis (CRS) is the most commonly reported complication. The aim of this study was to compare sepsis rates between neonates receiving PN by CVC and by peripheral cannula. Neonates were randomized to receive PN either by CVC or by peripheral cannula. Primary outcomes were sepsis rates and efficacy of PN delivery. Interim analysis (49 neonates) revealed no difference in sepsis rates (CVC group 46%, cannula group 40%, p = 0.57). There was a significant discrepancy in PN delivered (median deficit 3.2% in the CVC group, 10.3% in the cannula group, p=0.0014). After consideration of these findings the study was terminated. CONCLUSION: Because the trial was stopped early, small but clinically important differences in the rates of sepsis may have been missed. Neonates in the cannula group accrued significant deficits of PN owing to a lack of venous access. This may contribute to undernutrition in neonates. CVC can be advocated for PN administration, in that sepsis appears to be no higher than when using cannulae and delivery of nutrition is significantly better.

Catheterization↗

The technological edge.

An advanced 3D digital imaging system has been developed under the MedLINK programme that offers improved detection of breast cancer.

Breast Neoplasms↗

The technological edge.

A MedLINK project has developed a novel coating for needles that provides maximum ultrasound signal contrast, thus improving their visibility and aiding their accurate placement durning interventional procedures.

Biopsy, Needle↗

Metalloproteinase expression in normal and malignant oral keratinocytes: stimulation of MMP-2 and -9 by scatter factor.

Matrix metalloproteinases (MMPs) are Zn2+ dependent proteases produced by a variety of cell types. They have a fundamental role in tissue remodelling, tumour invasion and metastasis. Scatter factor (SF), secreted by fibroblasts, has a paracrine action on epithelial cells and binds the trans-membrane c-met receptor inducing loss of adhesion, cell motility and invasiveness in vitro. The purpose of this study was to test if SF can regulate the production of MMPs by epithelial cells. Supernatants from oral squamous cell carcinoma-derived cells (H375 and H376), a human keratinocyte line (UP), and primary cultures of oral mucosal keratinocytes, grown in the presence or absence of SF, were analysed using 0.1% gelatin zymography. MMPs were characterised by comparison with human recombinant enzymes and by the use of specific inhibitors. Oral mucosal keratinocytes, UP, and H357 cells expressed MMP-2 and MMP-9, whilst H376 cells only expressed MMP-2. SF increased the expression of MMP-9 in UP and MMP-2 in H376 supernatants. Both MMP-2 and MMP-9 activity were increased in H357 and normal keratinocyte supernatants. This could be blocked using a human recombinant anti-SF antibody. In all epithelial lines tested, c-Met, the cell surface receptor for SF, could be detected. The results indicate that SF stimulates MMP expression in UP, H376, H357, and normal oral mucosal cells and points to a role for SF in the regulation of oral keratinocyte behaviour in wound healing and neoplasia.

Analysis of Variance↗

Mechanisms of binding of cutaneous lymphocyte-associated antigen-positive and alphaebeta7-positive lymphocytes to oral and skin keratinocytes.

Intraepithelial lymphocytes (IEL) utilize the integrin alphaebeta7 on their surface to bind to E-cadherin on epithelial cells in the gut and breast. In oral mucosa and skin IEL express alphaebeta7 and the cutaneous lymphocyte-associated antigen (CLA) but the mechanisms of adhesion of these subsets to keratinocytes are unknown. Levels of alphaebeta7 and CLA were up-regulated on peripheral blood lymphocytes (PBL) by transforming growth factor-beta (TGF-beta) and interleukin-12 (IL-12), respectively, and both groups of lymphocytes adhered onto oral and skin keratinocytes. Adhesion of IL-12-activated PBL was totally abolished by anti-lymphocyte-associated function antigen type 1 (anti-LFA-1) antibodies but was unaffected by anti-alphaebeta7 antibodies indicating that adhesion of the CLA-positive subset is mediated via LFA-1 interaction with intercellular adhesion molecule-1 (ICAM-1). Adhesion of TGF-beta-activated PBL to E-cadherin-positive oral and skin keratinocytes was partially inhibited by anti-alphaebeta7 antibodies but was unaffected by the blocking antibody E4.6 against E-cadherin which detects the binding site for alphaebeta7-positive lymphocytes in breast and gut epithelium. TGF-beta-activated PBL also bound to an E-cadherin-negative oral keratinocyte cell line and adhesion was inhibited by anti-alphaebeta7 antibodies. These results strongly suggest that in oral epithelium and epidermis alphaebeta7-positive lymphocytes do not bind to E-cadherin and there may be a novel second ligand for the alphaebeta7 integrin.

Animals↗

Activation of the FGF receptor underlies neurite outgrowth stimulated by L1, N-CAM, and N-cadherin.

Cell contact-dependent neurite outgrowth stimulated by CAMs requires activation of a second messenger pathway that requires the function of a tyrosine kinase upstream from calcium influx into neurons. In the present study, we present evidence that implicates activation of the fibroblast growth factor receptor (FGFR) in the pathway underlying neurite outgrowth stimulated by L1, N-CAM, and N-cadherin. We have identified a CAM homology domain in the FGF family of receptors and show that antibodies which bind to this domain specifically inhibit neurite outgrowth stimulated by the above CAMs. We also show that synthetic peptides derived from this domain can differentially and specifically inhibit neurite outgrowth stimulated by L1, N-CAM, and N-cadherin. In addition, a soluble L1-Fc chimera is shown to stimulate an increase in phosphotyrosine on the same set of neuronal proteins that are phosphorylated following activation of the FGFR with basic FGF.

Amino Acid Sequence↗

Neurite outgrowth stimulated by the tyrosine kinase inhibitor herbimycin A requires activation of tyrosine kinases and protein kinase C.

Activation of tyrosine kinases is established as an important mechanism for controlling growth cone motility and neurite outgrowth. We have tested the effects of a range of tyrosine kinase inhibitors on neurite outgrowth from postnatal day 4 cerebellar granule cells cultured over confluent monolayers of 3T3 fibroblasts. The only agent that had any effect was herbimycin A, which stimulated neurite outgrowth. The response is shown to be attributable to a direct effect of this tyrosine kinase inhibitor on neurones. The neurite outgrowth response to herbimycin A was inhibited by two other tyrosine kinase inhibitors, which on their own did not affect neurite outgrowth. The data suggest that the response to herbimycin A reflects either a direct or indirect activation of one or more protein tyrosine kinases. Independent signalling events down-stream from tyrosine kinase activation underlying the neurite outgrowth response to herbimycin A include increased activity of protein kinase C and calcium influx into neurones through both N- and L-type calcium channels.

Animals↗

Characterisation of the second messenger pathway underlying neurite outgrowth stimulated by FGF.

Cerebellar neurons, cultured on monolayers of 3T3 fibroblasts or on a polylysine/laminin-coated substratum, responded to recombinant basic FGF by extending longer neurites. The response was biphasic reaching a maximum at 5 ng/ml FGF, but desensitising at 100-200 ng/ml FGF. The response to FGF could be inhibited by a tyrosine kinase inhibitor (the erbstatin analogue), by a diacylglycerol lipase inhibitor (RHC-80267) and by a combination of N- and L-type calcium channel antagonists or other agents that negate the effects of calcium influx into neurons. The response to FGF could be fully mimicked by arachidonic acid added directly to the cultures, or generated via activation of phospholipase A2 with melittin. The response to melittin, but not to FGF or arachidonic acid, was inhibited by 4-bromophenacyl bromide, a phospholipase A2 inhibitor. The response to arachidonic acid was also biphasic and high concentrations of this agent could cross-desensitise the FGF response and vice versa. The response to arachidonic acid could be fully inhibited by the agents that block or negate the effects of calcium influx into neurons, but was not inhibited by the tyrosine kinase or diacylglycerol lipase inhibitors. These data suggest that FGF stimulates neurite outgrowth by activating a cascade that involves activation of phospholipase C gamma to produce diacylglycerol, conversion of diacylglycerol to arachidonic acid by diacylglycerol lipase and the activation of voltage-gated calcium channels by arachidonic acid.

3T3 Cells↗

The peace dividend. Part I.

As companies traditionally involved in manufacturing for the aerospace and defence sectors come to terms with shrinking markets, their need to diversify into new markets is apparent. The potential for crossover from the aerospace to medical sectors is striking, if not ironic, and the technology that helped produce weapons of destruction is now being put to good use improving the quality of life. This potential will be examined in two articles, the first concentrating on the use of titanium.

Ceramics↗

Use of the neural cell adhesion molecule VASE exon by neurons is associated with a specific down-regulation of neural cell adhesion molecule-dependent neurite outgrowth in the developing cerebellum and hippocampus.

The development of the CNS is associated with an increasing use of the 30-bp variable alternative, spliced exon (VASE) in neural cell adhesion molecule (NCAM). We have assessed the relative usage of VASE by reverse transcriptase-linked polymerase chain reaction in the developing cerebellum and hippocampus at times when neurons isolated from these tissues can respond to substrate-associated NCAM by increased axonal growth and also at later developmental stages, when they are no longer responsive to substrate-associated NCAM. Neurons isolated from the developing cerebellum at postnatal day 6 respond to NCAM with increased neurite growth. NCAM transcripts from these cells were found to have negligible levels of VASE usage. In contrast, neurons that are isolated at later stages of development (postnatal days 8, 10, and 11) and do not respond to NCAM were found to synthesise a much higher proportion of NCAM transcripts containing VASE. In the hippocampus, embryonic day 18 neurons, which are responsive to NCAM, express low levels of VASE, whereas postnatal days 4 and 5 neurons, which are not responsive to NCAM, have a greater proportion of transcripts containing VASE. Thus, the level of NCAM VASE exon usage by neurons appears to be a good indicator of the ability of these cells to respond to non-VASE-containing NCAM (expressed in a cellular substratum) by increased neurite outgrowth.

Alternative Splicing↗

A general review of bite-mark evidence.

Bite-mark evidence has been used as an aid in the identification of criminals in many instances. The author, a forensic odontologist in Liverpool, England, during his lifetime, personally investigated the cases presented which include instances of rape and battery. It is shown how perpetrators of violent injuries were detected from bite marks on the victim or the perpetrator, or on foodstuffs found at the scene of the crime, when the marks were compared to dental impressions taken subsequently.

Battered Child Syndrome↗