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1.
BMJ Support Palliat Care ; 9(4): e26, 2019 Dec.
Article in English | MEDLINE | ID: mdl-26850118

ABSTRACT

OBJECTIVE: To evaluate 'Gold Line', a 24/7, nurse-led telephone and video-consultation support service for patients thought to be in the last year of life in Bradford, Airedale, Wharfedale and Craven. METHOD: Data on the time and nature of all calls between 1 April 2014 and 30 March 2015 were obtained from the patient Electronic Records. Interviews with 13 participants captured patients and carers perspectives. RESULTS: To date, 3291 patients have been referred to the Gold Line. During the study period, 42% of registered patients had a non-cancer diagnosis and 45.2% of service users were not known to Specialist Palliative Care services. The median time on the caseload was 49 days (range 1-504 days). 4533 telephone calls and 573 video consultations were made involving 1813 individuals. 39% of the 5106 contacts were resolved by the Gold Line team without referral to other services. 69% of calls were made outside normal working hours. Interviews with patients and carers reported experiences of support and reassurance from the Gold Line and the importance of practical advice was emphasised. Current data (year to October 2015) show that 98.5% of calls (4500/4568) resulted in patients remaining in their place of residence. CONCLUSIONS: A nurse led, 24/7 telephone and video consultation service can provide valuable support for patients identified to be in the last year of life and for their carers. The line enabled them to feel supported and remain in their place of residence, hence reducing the pressure for avoidable hospital admissions and use of other services. Providing this service may encourage healthcare professionals to identify more patients approaching the last year of life, widening support offered to this group of patients beyond those known to specialist palliative care services.


Subject(s)
Home Care Services/statistics & numerical data , Palliative Care/methods , Practice Patterns, Nurses'/statistics & numerical data , Telemedicine/methods , Terminal Care/methods , Adult , Aged , Aged, 80 and over , Caregivers/psychology , Female , Friends , Humans , Male , Middle Aged , Patient Acceptance of Health Care/psychology , Referral and Consultation/statistics & numerical data , Telephone
2.
Opt Express ; 25(21): 25546-25565, 2017 Oct 16.
Article in English | MEDLINE | ID: mdl-29041221

ABSTRACT

In an attempt to develop a streamlined astrophotonic instrument, we demonstrate the realization of an all-photonic device capable of both multimode to single mode conversion and spectral dispersion on an 8-m class telescope with efficient coupling. The device was a monolithic photonic spectrograph which combined an integrated photonic lantern and an efficient arrayed waveguide grating device. During on-sky testing, we discovered a previously unreported type of noise that made spectral extraction and calibration extremely difficult. The source of the noise was traced to a wavelength-dependent loss mechanism between the feed fiber's multimode near-field pattern and the modal acceptance profile of the integrated photonic lantern. Extensive modeling of the photonic components replicates the wavelength-dependent loss, and demonstrates an identical effect on the final spectral output. We outline that this could be mitigated by directly injecting into the integrated photonic lantern.

3.
Opt Express ; 25(15): 17753-17766, 2017 Jul 24.
Article in English | MEDLINE | ID: mdl-28789267

ABSTRACT

We demonstrate for the first time an efficient, photonic-based astronomical spectrograph on the 8-m Subaru Telescope. An extreme adaptive optics system is combined with pupil apodiziation optics to efficiently inject light directly into a single-mode fiber, which feeds a compact cross-dispersed spectrograph based on array waveguide grating technology. The instrument currently offers a throughput of 5% from sky-to-detector which we outline could easily be upgraded to ∼ 13% (assuming a coupling efficiency of 50%). The isolated spectrograph throughput from the single-mode fiber to detector was 42% at 1550 nm. The coupling efficiency into the single-mode fiber was limited by the achievable Strehl ratio on a given night. A coupling efficiency of 47% has been achieved with ∼ 60% Strehl ratio on-sky to date. Improvements to the adaptive optics system will enable 90% Strehl ratio and a coupling of up to 67% eventually. This work demonstrates that the unique combination of advanced technologies enables the realization of a compact and highly efficient spectrograph, setting a precedent for future instrument design on very-large and extremely-large telescopes.

5.
Ann Vasc Surg ; 29(4): 838.e11-5, 2015.
Article in English | MEDLINE | ID: mdl-25681637

ABSTRACT

Acquired coarctation of the thoracic aorta is a rare phenomenon in adults. The etiology is often idiopathic, but severe stenosis can develop from prior surgery, blunt thoracic aortic injuries, or severe atherosclerotic/atheroembolic disease. Common symptomatic presentations include refractory upper extremity hypertension and new-onset congestive heart failure. We present the case of a 52-year-old man who developed acquired thoracic aortic coarctation 30 years after a blunt trauma and deceleration injuries to the aorta requiring open surgical aortic repair. He presented with poorly controlled hypertension and new-onset heart failure and was treated surgically with endovascular repair.


Subject(s)
Aorta, Thoracic/surgery , Blood Vessel Prosthesis Implantation , Endovascular Procedures , Heart Failure/etiology , Thoracic Injuries/surgery , Vascular System Injuries/surgery , Wounds, Nonpenetrating/surgery , Accidents, Traffic , Aorta, Thoracic/diagnostic imaging , Aorta, Thoracic/injuries , Aortography/methods , Constriction, Pathologic , Heart Failure/diagnosis , Humans , Male , Middle Aged , Thoracic Injuries/diagnosis , Thoracic Injuries/etiology , Time Factors , Tomography, X-Ray Computed , Treatment Outcome , Vascular System Injuries/diagnosis , Vascular System Injuries/etiology , Wounds, Nonpenetrating/diagnosis , Wounds, Nonpenetrating/etiology
6.
Int J Surg Case Rep ; 7C: 89-92, 2015.
Article in English | MEDLINE | ID: mdl-25598402

ABSTRACT

INTRODUCTION: Renal angiomyolipoma (AML) is a benign mesenchymal tumour of the kidney with a tendency of aneurysm formation at risk of rupturing. Due to increased maternal circulation and hormonal influences, rupture risk is greater in pregnancy, often leading to a vascular emergency and premature delivery or termination. PRESENTATION OF CASE: A 24-weeks pregnant woman (45 years old, G6P1) presented with haematuria and flank pain. CT showed AML with acute haemorrhage. The patient became haemodynamically unstable and underwent urgent embolisation and follow-on total radical nephrectomy with the foetus being left in-utero. This involved a multidisciplinary team (urologist, vascular surgeon, interventional radiologist and obstetrician). The procedure was uncomplicated and the pregnancy went to term with a healthy girl delivered at 38 weeks. DISCUSSION: The incidence of AML is 0.13% in the general population. 21 reports of haemorrhaging AML in pregnancy have been published in the last 35 years. Mean gestational age was 29.6 weeks. Eight were treated conservatively to term, one underwent exploratory laparotomy with evacuation of haematoma only, five were embolised, and seven were managed with nephrectomy. Of the nephrectomy subgroup, one was preceded by vaginal delivery and five underwent concurrent caesarean section (one with pre-op embolisation). There were two associated foetal deaths. CONCLUSION: This case demonstrates that with a multidisciplinary approach, it is possible to successfully leave a foetus undelivered whilst performing a radical nephrectomy for a large bleeding AML in a woman carrying a late second trimester pregnancy.

7.
Breast Cancer Res Treat ; 112(3): 453-9, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18193353

ABSTRACT

BACKGROUND: HER2 gene amplification and/or protein overexpression in breast cancer is associated with a poor prognosis and predicts response to anti-HER2 therapy. We examine the natural history of breast cancers in relationship to increased HER2 copy numbers in a large population-based study. PATIENTS AND METHODS: HER2 status was measured by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) in approximately 1,400 breast cancer cases with greater than 15 years of follow-up. Protein expression was evaluated with two different commercially-available antibodies. RESULTS: We looked for subgroups of breast cancer with different clinical outcomes, based on HER2 FISH amplification ratio. The current HER2 ratio cut point for classifying HER2 positive and negative cases is 2.2. However, we found an increased risk of disease-specific death associated with FISH ratios of >1.5. An 'intermediate' group of cases with HER2 ratios between 1.5 and 2.2 was found to have a significantly better outcome than the conventional 'amplified' group (HER2 ratio >2.2) but a significantly worse outcome than groups with FISH ratios less than 1.5. CONCLUSION: Breast cancers with increased HER2 copy numbers (low level HER2 amplification), below the currently accepted positive threshold ratio of 2.2, showed a distinct, intermediate outcome when compared to HER2 unamplified tumors and tumors with HER2 ratios greater than 2.2. These findings suggest that a new cut point to determine HER2 positivity, at a ratio of 1.5 (well below the current recommended cut point of 2.2), should be evaluated.


Subject(s)
Genes, erbB-2 , Receptor, ErbB-2/genetics , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Cohort Studies , Female , Follow-Up Studies , Gene Amplification , Humans , Immunohistochemistry/methods , In Situ Hybridization, Fluorescence/methods , Multivariate Analysis , Prognosis , Proportional Hazards Models , Receptor, ErbB-2/biosynthesis , Receptor, ErbB-2/physiology , Receptors, Estrogen/metabolism , Treatment Outcome
8.
Vet Microbiol ; 128(3-4): 217-30, 2008 Apr 30.
Article in English | MEDLINE | ID: mdl-18055136

ABSTRACT

Fleece rot and dermatophilosis reduce health and production of sheep and predispose them to blow fly strike. This paper reviews aetiology, prevalence, pathogenesis, resistance, attempts to develop vaccines and prospects for new control strategies to these important skin diseases. Although the severity of fleece rot is associated with the abundance of Pseudomonas aeruginosa on skin, microbial ecology studies are providing new insights into the contribution of other bacteria to the disease. Wool traits and body conformation traits that predispose sheep to fleece rot and dermatophilosis are heritable and have been used as indirect selection criteria for resistance for many years. Selection against BoLA-DRB3-DQB class II haplotype in cattle can substantially reduce the prevalence of dermatophilosis and holds promise for identification of gene markers for resistance to these bacterial diseases in sheep. Immune responses in skin and systemic antibody responses to bacterial antigens are acquired through natural infection and contribute to resistance; however, prototype antibacterial vaccines have to date failed to provide protection against the diversity of isolates of Dermatophilus congolensis and Pseudomonas species present in the field. Opportunities for future control through breeding for resistance, vaccines and non-vaccine strategies for controlling the microbial ecology of fleece are discussed. In combination, control strategies need to reduce the risk of transmission, minimise exposure of animals to stressors that enhance the risk of infection, and enhance resistance though genetics or vaccines.


Subject(s)
Actinomycetales Infections/veterinary , Bacterial Vaccines , Dermatitis/veterinary , Pseudomonas Infections/veterinary , Sheep Diseases/microbiology , Wool/microbiology , Actinomycetales/immunology , Actinomycetales Infections/microbiology , Actinomycetales Infections/pathology , Actinomycetales Infections/prevention & control , Animals , Dermatitis/microbiology , Dermatitis/pathology , Dermatitis/prevention & control , Disease Susceptibility/immunology , Disease Susceptibility/veterinary , Genetic Predisposition to Disease , Immunity, Innate/genetics , Immunity, Innate/immunology , Pseudomonas Infections/microbiology , Pseudomonas Infections/pathology , Pseudomonas Infections/prevention & control , Pseudomonas aeruginosa/immunology , Sheep , Sheep Diseases/pathology , Sheep Diseases/prevention & control
9.
Ann Oncol ; 18(10): 1646-51, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17716984

ABSTRACT

BACKGROUND: Dose-dense and dose-intensive regimens have improved the outcome of breast cancer in high-risk women with operable disease. PATIENTS AND METHODS: Sixty-three premenopausal women with Stage 2, 3 breast cancer and > or =4 positive axillary nodes were treated in three successive cohorts with 70 mg/m(2) of epirubicin, 500 mg/m(2) of 5-fluorouracil and G-CSF every 14 days for 12 cycles. Cyclophosphamide (C) was given at 700 mg/m(2), 900 mg/m(2), and 1100 mg/m(2) doses. Patients were evaluated for dose-limiting toxicities (DLTs) in the first four cycles, the primary endpoint of the trial. RESULTS: No DLTs were seen at C 700 mg/m(2); at C 900 mg/m(2) two of 16 patients experienced febrile neutropenia and poor performance status; at C 1100 mg/m(2), 1 of 31 patients experienced poor performance status. Over 6 months, febrile neutropenia, grade 4 thrombocytopenia, grade 3 anemia and severe fatigue were observed. Clinical congestive heart failure occurred in three patients over 4 years. CONCLUSION: A dose-intense and dose-dense regimen of cyclophosphamide, epirubicin and 5-fluorouracil was delivered with G-CSF without apparent increase in acute toxicity. Cyclophosphamide could be increased to more than twice the standard dose at the cost of more anemia and fatigue.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Adult , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Chemotherapy, Adjuvant , Cyclophosphamide/administration & dosage , Cyclophosphamide/adverse effects , Epirubicin/administration & dosage , Epirubicin/adverse effects , Female , Fluorouracil/administration & dosage , Fluorouracil/adverse effects , Granulocyte Colony-Stimulating Factor/administration & dosage , Granulocyte Colony-Stimulating Factor/adverse effects , Humans , Lymphatic Metastasis , Premenopause
10.
Ann Oncol ; 18(1): 45-51, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17030545

ABSTRACT

BACKGROUND: Letrozole after 5 years of adjuvant tamoxifen results in a significant reduction in risk of recurrence from estrogen receptor (ER) positive breast cancer. An individualized estimate of the risk of relapse and death after 5 years of tamoxifen could improve decisions regarding extended hormonal therapy. METHODS: The British Columbia Breast Cancer Outcomes database was used to identify women aged 45 years or older at the time of diagnosis with early-stage (I-IIIA) breast cancer who received tamoxifen and were disease free 5 years after diagnosis. Ten-year breast cancer event rates and mortality were calculated as well as annualized hazard rates of recurrence. RESULTS: A total of 1086 women were identified with a median age of 64 years and follow-up of 10.5 years. The relative risk (RR) of death was 3.1 (P=0.003) and for recurrence was 1.7 (P=0.037) for N1 (one to three positive nodes) versus N0 (zero nodes positive) disease. N2 (four to nine nodes positive) had a RR of 5.8 (P<0.001) for death and 3.0 (P=0.002) for recurrence. Low tumor grade and high ER level subgroups had a more favorable prognosis. Annual breast cancer risk between years 6 and 10 was, respectively, 2.2%, 3.5% and 7.6% for N0, N1 and N2 disease and 2.6% and 4.5% for T1 and T2 breast cancer. CONCLUSION: T and N stages predicted late relapse and death from breast cancer in a population-based cohort of postmenopausal women. Risk estimates reported herein may be used to optimize decision making regarding adjuvant therapy after 5 years of tamoxifen.


Subject(s)
Antineoplastic Agents, Hormonal/therapeutic use , Breast Neoplasms/mortality , Neoplasm Recurrence, Local/mortality , Neoplasms, Hormone-Dependent/mortality , Postmenopause , Tamoxifen/therapeutic use , Aged , Aged, 80 and over , Aromatase Inhibitors/therapeutic use , Breast Neoplasms/drug therapy , British Columbia , Carcinoma, Ductal, Breast/drug therapy , Carcinoma, Ductal, Breast/mortality , Carcinoma, Lobular/drug therapy , Carcinoma, Lobular/mortality , Chemotherapy, Adjuvant , Female , Humans , Letrozole , Middle Aged , Neoplasm Invasiveness , Neoplasm Staging , Neoplasms, Hormone-Dependent/drug therapy , Nitriles/therapeutic use , Prognosis , Risk Factors , Survival Rate , Triazoles/therapeutic use
11.
Ergonomics ; 49(12-13): 1370-94, 2006.
Article in English | MEDLINE | ID: mdl-17008261

ABSTRACT

There is an increasing prevalence for work to be analysed through naturalistic study, especially using ethnographically derived methods of enquiry and qualitative field research. The relatively unexplored domain of railway control (in comparison to signalling) in the UK is described in terms of features derived from observations and semi-structured interviews. In addition, task diagrams (a technique taken from the Applied Cognitive Task Analysis toolkit) are used to represent controllers' core elements of work, i.e. to manage events or incidents, and to identify the challenging steps in the process. The work features identified, the task diagrams, and the steps identified as challenging form a basis from which future ergonomics studies on railway controllers in the UK will be carried out.


Subject(s)
Cognition , Efficiency , Ergonomics , Railroads , User-Computer Interface , Data Collection , Humans , Interviews as Topic , Systems Analysis , Task Performance and Analysis , United Kingdom
12.
J Inorg Biochem ; 99(12): 2362-71, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16266750

ABSTRACT

Cadmium ions applied to either (outer or inner) surface of the isolated toad skin dose-dependently increased the short-circuit current (SCC), the potential difference (V) and the active sodium conductance (G(Na)) in the concentration range 0.07-0.50mM. Maximal stimulatory effect was over 30% with an EC(50) of about 0.1mM. The effect of the highest concentration used (0.75mM) decreased considerably, and when it was applied to the inner surface (10 experiments), induced between 30% and 40% inhibition of the electric parameters in four experiments. Pretreatment with amiloride inverted the stimulatory effect of externally applied Cd(2+), suggesting competitive action on the apical Na(+) channel. The effect of noradrenaline (NA) was increased after outer application of Cd(2+) and decreased after inner application of the metal: the latter effect might be due to cadmium inhibition of the activity of Na(+),K(+)-ATPase. On the other hand, pretreatment with amiloride was followed by partial although transient reversal of its effects by serosal Cd(2+), which might be explained by action of cadmium on cytoplasmic lysine residues concerned with Na(+) channel gating. The amiloride test showed that the increment of the electric parameters was due principally to stimulation of the driving potential for Na(+) (V-E(Na(+))) and that inhibition was accompanied by a reduction in the V-E(Na(+)) and by a significant decrease in skin resistance indicating possible disruption of membrane or cell integrity. These data are in favor of the possibility that externally applied Cd(2+) activates toad skin ion transport, partly by increasing apical sodium conductance and also by stimulating the V-E(Na(+)), and that internally applied Cd(2+), with easier access to membrane and cellular constituents, may inhibit the sodium pump.


Subject(s)
Cadmium/toxicity , Skin/drug effects , Skin/metabolism , Sodium/metabolism , Amiloride/pharmacology , Animals , Anura , Environmental Pollutants/toxicity , Female , In Vitro Techniques , Ion Transport/drug effects , Male , Membrane Potentials/drug effects , Norepinephrine/pharmacology , Sodium Channel Blockers/pharmacology
13.
J Neurosci ; 25(46): 10773-85, 2005 Nov 16.
Article in English | MEDLINE | ID: mdl-16291951

ABSTRACT

We performed genomic subtraction coupled to microarray-based gene expression profiling and identified the PDZ (postsynaptic density-95/Discs large/zona occludens-1)-binding kinase/T-LAK (lymphokine-activated killer T cell) cell originating protein kinase (PBK/TOPK) as a gene highly enriched in neural stem cell cultures. Previous studies have identified PBK/TOPK as a mitogen-activated protein kinase (MAPK) kinase that phosphorylated P38 MAPK but with no known expression or function in the nervous system. First, using a novel, bioinformatics-based approach to assess cross-correlation in large microarray datasets, we generated the hypothesis of a cell-cycle-related role for PBK/TOPK in neural cells. We then demonstrated that both PBK/TOPK and P38 are activated in a cell-cycle-dependent manner in neuronal progenitor cells in vitro, and inhibition of this pathway disrupts progenitor proliferation and self-renewal, a core feature of progenitors. In vivo, PBK/TOPK is expressed in rapidly proliferating cells in the adult subependymal zone (SEZ) and early postnatal cerebellar external granular layer. Using an approach based on transgenically targeted ablation and lineage tracing in mice, we show that PBK/TOPK-positive cells in the SEZ are GFAP negative but arise from GFAP-positive neural stem cells during adult neurogenesis. Furthermore, ablation of the adult stem cell population leads to concomitant loss of PBK/TOPK-positive cells in the SEZ. Together, these studies demonstrate that PBK/TOPK is a marker for transiently amplifying neural progenitors in the SEZ. Additionally, they suggest that PBK/TOPK plays an important role in these progenitors, and further implicates the P38 MAPK pathway in general, as an important regulator of progenitor proliferation and self-renewal.


Subject(s)
Cell Proliferation , MAP Kinase Signaling System/physiology , Neurons/cytology , Neurons/enzymology , Protein Serine-Threonine Kinases/physiology , Stem Cells/cytology , Stem Cells/enzymology , Animals , Cattle , Cells, Cultured , Chickens , Dogs , Humans , Mice , Mice, Transgenic , Mitogen-Activated Protein Kinase Kinases , Oncorhynchus mykiss , Pan troglodytes , Protein Serine-Threonine Kinases/biosynthesis , Protein Serine-Threonine Kinases/genetics , Rats , Tetraodontiformes , Xenopus laevis , Zebrafish , p38 Mitogen-Activated Protein Kinases/physiology
14.
J Hered ; 96(5): 494-501, 2005.
Article in English | MEDLINE | ID: mdl-16135704

ABSTRACT

Sequence variation present within the mitochondrial genome was used to investigate genetic diversity within sheep breeds from Asia and Europe. Comparison of 2027 bp of sequence from 121 animals revealed 44 phylogenetically informative nucleotide positions and a single insertion/deletion. A total of 57 haplotypes were observed which formed two distinct clades. Type A haplotypes were found in breeds from Asia (India, Indonesia, Mongolia, and Tibet), while type B haplotypes were observed at the highest frequency in breeds sourced from Europe (nine breeds from Austria, Aland, Finland, Spain, and northwestern Russia). The distribution of haplotypes indicates sheep appear to have the weakest population structure and the highest rate of intercontinental dispersal of any domestic animal reported to date. Only 2.7% of the sequence variation observed was partitioned between continents, which is lower than both goat (approximately 10%) and cattle (approximately 50%). Diagnostic restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) tests which distinguish type A and B haplotypes were used to test an additional 223 animals from 17 breeds of European and Asian origin. A mixture of the two lineages was found in every breed except Suffolk and the Indian Garole, indicating introgression has played a major part during breed development and subsequent selection.


Subject(s)
Genetic Variation , Genetics, Population , Phylogeny , Sheep/genetics , Animals , Asia , Base Sequence , Cluster Analysis , DNA, Mitochondrial/genetics , Europe , Haplotypes/genetics , Molecular Sequence Data , Polymorphism, Single Nucleotide/genetics , Sequence Analysis, DNA
15.
J Inorg Biochem ; 99(3): 764-70, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15708797

ABSTRACT

The structural effects of titanium citrate on the human erythrocyte membrane were studied through its interaction with intact erythrocytes and isolated unsealed human erythrocyte membranes (IUM). The studies were carried out by scanning electron microscopy and fluorescence spectroscopy, respectively. Titanium citrate induced shape changes in erythrocytes, which were damaged and ruptured leaving empty and retracted membranes. Fluorescence spectroscopy measurements in IUM indicated a disordering effect at both the polar head group and the acyl chain packing arrangements of the membrane phospholipid bilayer. Titanium citrate also interacted with molecular models of the erythrocyte membrane consisting in bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representing classes of phospholipids located in the outer and inner monolayers of the erythrocyte membrane, respectively. X-ray diffraction indicated that titanium citrate induced structural perturbation of the polar head group and of the hydrophobic acyl regions of DMPC, while the effects on DMPE bilayers were negligible. This conclusion is supported by fluorescence spectroscopy measurements on DMPC large unilamellar vesicles. All these findings indicate that the structural perturbations induced by titanium to human erythrocytes can be extended to other cells, thereby affecting their functions.


Subject(s)
Citric Acid/pharmacology , Erythrocyte Membrane/drug effects , Lipid Bilayers/chemistry , Acylation , Citric Acid/chemistry , Citric Acid/metabolism , Dimyristoylphosphatidylcholine/chemistry , Dose-Response Relationship, Drug , Erythrocyte Membrane/chemistry , Erythrocyte Membrane/ultrastructure , Humans , Microscopy, Electron, Scanning , Phosphatidylethanolamines/chemistry , Spectrometry, Fluorescence , X-Ray Diffraction
16.
J Inorg Biochem ; 98(6): 1061-6, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15149816

ABSTRACT

The structural effects of cadmium on cell membranes were studied through the interaction of Cd(2+) ions with human erythrocytes and their isolated unsealed membranes (IUM). Studies were carried out by scanning electron microscopy and fluorescence spectroscopy, respectively. Cd(2+) induced shape changes in erythrocytes, which took the form of echinocytes. According to the bilayer couple hypothesis, this result meant that Cd(2+) ions located in the outer monolayer of the erythrocyte membrane. Fluorescence spectroscopy measurements in IUM indicated a disordering effect at both the polar headgroup and the acyl chain packing arrangements of the membrane phospholipid bilayer. Cd(2+) ions also interacted with molecular models of the erythrocyte membrane consisting in bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representing classes of phospholipids located in the outer and inner monolayers the erythrocyte membrane, respectively. X-ray diffraction indicated that Cd(2+) ions induced structural perturbation of the polar headgroup and of the hydrophobic acyl regions of DMPC, while the effects of cadmium on DMPE bilayers were much milder. This conclusion is supported by fluorescence spectroscopy measurements on DMPC large unilamellar vesicles (LUV). All these findings point to the important role of phospholipid bilayers in the interaction of cadmium on cell membranes.


Subject(s)
Cadmium Compounds/chemistry , Erythrocyte Membrane/chemistry , Lipid Bilayers/chemistry , Models, Chemical , Erythrocyte Membrane/ultrastructure , Humans , Microscopy, Electron, Scanning , Phospholipids/chemistry
17.
Food Chem Toxicol ; 42(6): 925-33, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15110101

ABSTRACT

No useful biological function for aluminum has been found. To the contrary, it might play an important role in several pathologies, which could be related to its interactions with cell membranes. On the other hand, fluoride is a normal component of body fluids, soft tissues, bones and teeth. Its sodium salt is frequently added to drinking water to prevent dental caries. However, large doses cause severe pathological alterations. In view of the toxicity of Al(3+) and F(-) ions, it was thought of interest to explore the damaging effects that AlF(3) might induce in cell membranes. With this aim, it was incubated with human erythrocytes, which were examined by phase contrast and scanning electron microscopy, and molecular models of biomembranes. The latter consisted of large unilamellar vesicles (LUV) of dimyristoylphosphatidylcholine (DMPC) and bilayers of DMPC and dimyristoylphosphatidylethanolamine (DMPE) which were studied by fluorescence spectroscopy and X-ray diffraction, respectively. In order to understand the effects of AlF(3) on ion transport (principally sodium and chloride) we used the isolated toad skin to which electrophysiological measurements were applied. It was found that AlF(3) altered the shape of erythrocytes inducing the formation of echinocytes. This effect was explained by X-ray diffraction which revealed that AlF(3) perturbed the structure of DMPC, class of lipids located in the outer monolayer of the erythrocyte membrane. This result was confirmed by fluorescence spectroscopy on DMPC LUV. The biphasic (stimulatory followed by inhibitory) effects on the isolated skin suggested changes in apical Cl(-) secretion and moderate ATPase inactivation.


Subject(s)
Aluminum Compounds/toxicity , Cell Membrane/drug effects , Fluorides/toxicity , Adult , Cell Culture Techniques , Cell Membrane/physiology , Electrophysiology , Erythrocytes/drug effects , Erythrocytes/physiology , Humans , Male , Models, Molecular , Spectrometry, Fluorescence , X-Ray Diffraction
18.
J Inorg Biochem ; 97(3): 308-13, 2003 Nov 01.
Article in English | MEDLINE | ID: mdl-14511893

ABSTRACT

Lead has no biological function; however, low, and particularly, high levels of exposure have a number of negative consequences for human health. Despite the number of reports about lead toxicity, very little information has been obtained regarding its effects on cell membranes. For this reason, the structural effects of lead on the human erythrocyte membranes were investigated. This aim was attained by making lead ions interact with intact erythrocytes, isolated unsealed erythrocyte membranes (IUM) and molecular models. The latter consisted of bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representing phospholipid classes located in the outer and inner monolayers of the human erythrocyte membrane. The results, obtained by electron microscopy, fluorescence spectroscopy and X-ray diffraction, indicated that (a) lead particles adhered to the external and internal surfaces of the human erythrocyte membrane; (b) lead ions disturbed the lamellar organization of IUM and DMPC large unilamellar vesicles (LUV) and (c) induced considerable molecular disorder in both lipid multilayers, the effects being much more pronounced in DMPC.


Subject(s)
Erythrocyte Membrane/drug effects , Lead/toxicity , Erythrocyte Membrane/ultrastructure , Fluorescence , Humans , Liposomes/chemistry , Liposomes/metabolism , Male , Models, Molecular , Phospholipids/metabolism , X-Ray Diffraction
19.
J Sci Med Sport ; 6(1): 71-5, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12801212

ABSTRACT

One hundred tennis players were recruited from the professional men's tennis tour to investigate the correlation between hip internal rotation deficits and low back pain (LBP), as well as shoulder internal rotation deficits and shoulder pain. A statistically significant correlation was observed between dominant shoulder internal rotation deficits and shoulder pain. Also observed was a statistically significant correlation between lead hip internal rotation deficits and lumbar extension deficits with LBP. We conclude that due to repetitive demands on the dominant shoulder and repetitive pivoting at the lead hip, the cycle of microtrauma and scar formation leads to capsular contracture and subsequent reduction in internal range of motion. It is likely that the limitation in lumbar extension in the symptomatic group is not only due to decreased flexibility from an increased load on the spine, but also due to a protective mechanism to prevent further exacerbation of the LBP. Physical conditioning that includes shoulder as well as hip internal rotation stretching programs should therefore be essential aspects in the treatment of tennis players with shoulder pain and LBP respectively.


Subject(s)
Hip Joint/physiopathology , Low Back Pain/physiopathology , Shoulder Joint/physiopathology , Shoulder Pain/physiopathology , Tennis/physiology , Adolescent , Adult , Humans , Male , Range of Motion, Articular
20.
Ann Oncol ; 14(4): 543-8, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12649098

ABSTRACT

BACKGROUND: ZD0473 is a new generation platinum compound with activity against a wide range of human tumor cell lines and xenografts, including carboplatin- and cisplatin-resistant lines. A phase II study of ZD0473 in advanced breast cancer was initiated by the National Cancer Institute of Canada Clinical Trials Group. PATIENTS AND METHODS: Women with metastatic breast cancer, measurable disease, an Eastern Cooperative Oncology Group performance status of up to two, and a maximum of one prior cytotoxic agent for recurrent disease were enrolled and treated at 120 mg/m(2) every 3 weeks. After 13 patients were enrolled, the dose was increased to 150 mg/m(2) on the basis of emergent data from studies ongoing at the time. RESULTS: Thirty-three women were evaluable for toxicity and 26 patients for response. Toxicity was mainly hematological with grade 3/4 thrombocytopenia in 12 of 20 patients (60%) treated at 150 mg/m(2) and grade 3 thrombocytopenia in three of 13 patients (23%) at 120 mg/m(2). Grade 3/4 neutropenia occurred in 15 patients (75%) at 150 mg/m(2) and two patients (10%) at 120 mg/m(2). Non-hematological toxicities were generally mild or moderate. There was one partial response seen for a response rate of 3.8% (95% confidence interval 0.1% to 19.5%) and stable disease in 15 patients. CONCLUSION: ZD0473 has minor activity as a single agent in metastatic breast cancer. Combinations with other drugs including docetaxel are ongoing and may be of interest.


Subject(s)
Breast Neoplasms/drug therapy , Organoplatinum Compounds/pharmacology , Adult , Aged , Breast Neoplasms/pathology , Disease Progression , Female , Humans , Infusions, Intravenous , Middle Aged , Neoplasm Metastasis , Neutropenia/chemically induced , Organoplatinum Compounds/administration & dosage , Organoplatinum Compounds/adverse effects , Treatment Outcome
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