A5018197403- Ion channel regulation and function
- Nitric Oxide and Endothelin Effects
- Neuroscience and Neuropharmacology Research
- Receptor Mechanisms and Signaling
- Platelet Disorders and Treatments
- Cardiac Ischemia and Reperfusion
- Cell Adhesion Molecules Research
- Adenosine and Purinergic Signaling
- Ion Transport and Channel Regulation
- Cardiac electrophysiology and arrhythmias
- Phosphodiesterase function and regulation
- Cardiac and Coronary Surgery Techniques
- Peptidase Inhibition and Analysis
- Protein Interaction Studies and Fluorescence Analysis
- Neurobiology and Insect Physiology Research
- Mitochondrial Function and Pathology
- Neuropeptides and Animal Physiology
- Blood properties and coagulation
- Physiological and biochemical adaptations
- Pancreatic function and diabetes
- Neurological Complications and Syndromes
- Coagulation, Bradykinin, Polyphosphates, and Angioedema
- Monoclonal and Polyclonal Antibodies Research
- Exercise and Physiological Responses
- 3D Printing in Biomedical Research
University of Liverpool
2005-2023
GlaxoSmithKline (United Kingdom)
2008-2020
University of Hertfordshire
2012
Queen Elizabeth Hospital
1987-2008
Institute of Cell Biology and Neurobiology
2000
Istituto Superiore di Sanità
1996-1997
University of Birmingham
1983-1995
John Radcliffe Hospital
1993
University of Wales
1993
University of Oxford
1988-1992
By using an endothelial cell line (ECV304), derived from human umbilical vein and transfected with recombinant aequorin targeted to the mitochondrial matrix, we find that stimulation ATP evokes long lasting increases in Ca2+ ([Ca2+]m) largely depend on influx. In these cells, release of stored is inefficient at elevating [Ca2+]m. Consequently it appears ECV304 bulk cytosolic ([Ca2+]c) main determinant [Ca2+]m changes.In cells <4% mitochondria are within 700 nm endoplasmic reticulum as...
Nucleotide activation of P2 receptors is important in autocrine and paracrine regulation many tissues. In the epidermis, nucleotides are involved proliferation, differentiation, apoptosis. this study, we have used a combination luciferin-luciferase luminometry, pharmacological inhibitors, confocal microscopy to demonstrate that HaCaT keratinocytes release ATP into culture medium, there three mechanisms for nucleotide interconversion, resulting generation at cell surface. Addition ADP, GTP,...
Product ion spectra produced by collision-induced dissociation (CID) in tandem mass spectrometry experiments can differ markedly between instruments. There have been a number of attempts to standardise the production product spectra; however, consensus on most appropriate approach reproducible has yet be reached. We previously reported comparison different types instruments - triple quadrupole, two traps and Fourier transform cyclotron resonance spectrometer (Bristow AWT, Webb KS, Lubben AT,...
The efflux of chloride across the plasmalemma internodal cells Nitella translucens and Clwra australis has been measured under various conditions. It is large in dark, reduced by light removal ions from external solution. Typical values for a concentration 1� 3 mM solution are: light, 0�6 pmole cm-2 sec-t, rising dark to about 4�0 sec-1 several hours, finally steady at 2� 5 sec-i. concluded that these changes are produced permeability membrane ions. two species give very similar results
The Staphylococcus epidermidis slime-associated antigen (SAA) was purified and characterized. N-Acetyl-glucosamine accounted for 70% of the dry weight SAA, which immunolocalized on ruthenium red-positive material produced by slime-positive strains. A total 59% slime-producing S. clinical isolates expressed while phenotype slime- SAA+ never recovered.
Tension and intracellular free calcium concentration ([Ca 2+ ] i ) were measured simultaneously in single smooth muscle cells isolated from the anterior byssus retractor (ABRM) of Mytilus edulis that loaded with fluorescent Ca indicator fura-2. Electrical stimulation evoked a transient elevation [Ca associated "catch" contraction. During catch state, however, was effectively at its resting level unaffected by 5-hydroxytryptamine, which induced rapid relaxation catch. The results indicate...
TMB‐8 is widely regarded as an ‘intracellular calcium antagonist’, supposedly inhibiting the mobilisation of intracellular calcium. Rarely, however, have effects this compound on Ca 2+ movements been measured. We report here that not very effective in thrombin‐induced influx or internal release human platelets judged from fluorescent signal cytoplasmic quin2. Only approx. 40% inhibition was seen at 500 μm TMB‐8. Somewhat lower concentrations blocked secretory response to thrombin and also...
Human platelets were co-loaded with the fluorescent indicators BCECF and fura-2 to measure pHi [Ca2+]i incubated aspirin block cyclooxygenase. Either shape change aggregation or measured simultaneously in same stirred cuvette, at 37 degrees C. In Hepes-buffered saline containing 1 mM Ca2+, mean resting was 6.98 +/- 0.01 (SE, n = 59). Changes of up 0.35 units, imposed by additions NH4Cl, CO2 nigericin, produced no only insignificant changes [Ca2+]i. Sufficient thrombin raise over microM cause...
In acute leukaemia, low plasma fibronectin was seen at diagnosis and when the disease relapsed. This not directly related to tumour load, chemotherapy or neutropenia, but correlated well with episodes of intercurrent infection. severe infections, fell rapidly very levels, sometimes restored normal up 2 weeks later. Preliminary attempts replacement therapy were successful possible importance this is discussed.
We examined whether localized increases in cytosolic cGMP have distinct regulatory effects on the concentration of free Ca2+ ECV304 cells. Stimulation particulate guanylate cyclase by brain-type natriuretic peptide fura-2-loaded cells caused a profound potentiation ATP-stimulated and thapsigargin-stimulated rise Ca2+. This effect is mediated inhibition extrusion via plasma membrane Ca2+-ATPase pump. Furthermore, addition partial cation influx In contrast, elevation activation soluble induced...
The discovery and development of an efficient more sustainable manufacturing route to the anti-pneumocystic agent atovaquone (2-((1R,4R)-4-(4-chlorophenyl)cyclohexyl)-3-hydroxynaphthalene-1,4-dione) 1 is described. existing commercial delivers a poor yield product uses expensive reagents. new synthesis commences with readily available phthalic anhydride, which converted 1,4-isochromandione 5 then by reaction 4-(4-chlorophenyl)cyclohexanecarboxylic acid 3 using key bromination, Rosenmund...
In fura-2-loaded A10 vascular smooth-muscle cells, 1 nM-vasopressin and 200 nM-endothelin evoked a rapid transient rise in intracellular free Ca2+ concentration [(Ca2+]i), which was then followed by maintained elevation of [Ca2+]i. The [Ca2+]i only partially inhibited 5 microM-nifedipine, but completely abolished the presence mM-EGTA. When extracellular replaced with mM-Mn2+ (Mn2+ quenches fura-2 fluorescence), both endothelin vasopressin an Mn2+ quench fluorescence from intracellularly...
Precise control of the level protein expression in cells can yield quantitative and temporal information on role a given gene normal cellular physiology exposure to chemicals drugs. This is particularly relevant liver cells, which many proteins, such as phase I II drug-metabolizing enzymes, vary widely between species, among individual humans, xenobiotics. The most used regulatory system has been tet-on/off approach. Although second-generation tet-on transactivator was recently described, it...
U44069 Ionomycin Ca 2+ Shape change Platelet Platelet‐activating factor
Calcium is an important regulator of mitochondrial function. Since there can be tight coupling between inositol 1,4,5-trisphosphate-sensitive Ca2+ release and elevation calcium concentration, we have investigated whether a similar relationship exists the from ryanodine receptor Ca2+. Perfusion permeabilized A10 cells with 1,4,5-trisphosphate resulted in large transient to about 8 μm. The response was inhibited by heparin but not ryanodine. buffers excess 1 μm leads increases that are much...
The effects of siguazodan (SK&F 94836) a selective phosphodiesterase (PDE) inhibitor with inotropic and vasodilator activity, were studied on human platelets. Siguazodan selectively inhibited the major cyclic AMP‐hydrolysing PDE in platelet supernatants. enzyme has been variously termed GMP‐inhibited or PDE‐III. In platelet‐rich plasma (PRP), U46619‐induced aggregation more potently than that induced by ADP collagen. Treatment PRP aspirin had no effect potency siguazodan. washed...
We hypothesized that slime may mask bacterial molecules important in the attachment of Staphylococcus epidermidis to inanimate surfaces. In support this hypothesis, we found slime-negative strains attached significantly better fibrinogen or fibronectin than parent and exhibited greater surface hydrophobicity. Comparable results were obtained with 53 clinical isolates.