51
|
Sheth N, Mistry N, Chen Y, Yang C. SU-E-T-428: Class Solution for Prostate High Dose Rate Brachytherapy with Inverse Planning Simulated Annealing. Med Phys 2012; 39:3803. [DOI: 10.1118/1.4735517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
52
|
Zhang H, Diwanji T, Mistry N, Lu W, D'Souza W. TU-E-BRA-10: Personalized Utility Function for Radiotherapy Based on Pulmonary Ventilation of Locally Advanced Lung Cancer Patients. Med Phys 2012; 39:3913. [PMID: 28518671 DOI: 10.1118/1.4735970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To develop tailor-made utility functions based on each patient's pulmonary function distribution so that personalized organ-function-based treatment plan is obtained for locally advanced lung cancer patients. METHODS Five locally advanced lung cancer patients were retrospectively evaluated in the study. Fractional regional ventilation was obtained by performing subtraction of spatially matched and corrected 4DCT images. Histogram of the fraction ventilation values was generated for each patient. The cumulative distribution function (CDF), which represented an inverse relationship with the desired dose to each voxel for function preservation, showed potential as personalized utility function. In order to spare the majority of the volume with pulmonary function, a more aggressive utility function was defined as a piece-wise linear function based on the most frequent fractional ventilation value (peak of the histogram). This utility function was used in the objective function during treatment planning. Conventional objectives and constraints were maintained during the planning process. RESULTS Both conventional plan and personalized functional plan were classified as satisfactory plans by physician based on conventional dose and dose-volume metrics. However, functional plan successfully spared high ventilation volume based on each patient's unique condition. When spatial function information was included to collect function dose/dose-volume metrics, significant reduction of fV20, fV30 and mean lung dose was achieved by function-based personalized plan with p-value < 0.01. CONCLUSIONS Organ-function-based radiotherapy has been presented to incorporate patient's pulmonary function in hopes of reducing the risk of complications. Current methods utilize the function information in the same fashion across patients. We took one step further to not only incorporate heterogeneous pulmonary function during treatment planning but also generate personalized utility function based on the function distribution of each patient. AAPM Research Seed Funding Initiative.
Collapse
|
53
|
Mistry N, Dixon J, Tallantyre E, Tench C, Abdel-Fahim R, Jaspan T, Morgan P, Morris P, Evangelou N. A Single 7 Tesla MRI Brain Scan Predicts Multiple Sclerosis in Cases with Initial Diagnostic Uncertainty (S10.004). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.s10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
54
|
Mistry N, Rockley TJ, Reynolds T, Hopkins C. Development and validation of a symptom questionnaire for recording outcomes in adult lacrimal surgery. Rhinology 2012; 49:538-45. [PMID: 22125784 DOI: 10.4193/rhino11.042] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND A symptom-based questionnaire (the `Lac-Q` questionnaire) for adult patients undergoing lacrimal drainage surgery was developed. The questionnaire yields a numerical score that can be used to assess severity of symptoms. METHODOLOGY In this study, the questionnaire was evaluated in 17 consecutive patients undergoing 22 dacryocystorhinostomy (DCR) procedures. The questionnaire was administered pre- and postoperatively. The pathology encountered at operation was recorded. The success of surgery was judged by patient satisfaction, endoscopic evaluation of DCR stomal patency, and objective lacrimal drainage testing using the functional endoscopic dye test (FEDT). In a further group of 12 pre-operative cases, the questionnaire was repeated after 4-6 weeks but before surgery, to assess test-retest reliability in the absence of clinical change. RESULTS The Lac-Q questionnaire was based on two broad categories of eye-specific scores and social impact scores. A numerical score, the `Lac-Q` score, was generated pre- and postoperatively. When compared to pre-operative scores, the reduction in Lac-Q scores postoperatively was significant. Postoperative scores also correlated well with objective lacrimal drainage testing using the FEDT. Analysis of symptom scores shows that the questionnaire was reliable with regard to content validity, internal consistency, test-retest reliability, and responsiveness to clinical change. CONCLUSIONS We conclude that the Lac-Q questionnaire is a useful clinical tool to evaluate outcomes after adult lacrimal surgery.
Collapse
|
55
|
Mistry N, Dixon J, Tallantyre E, Jaspan T, Morgan P, Morris P, Evangelou N. 0930 A single 7T MRI brain scan accurately predicts eventual diagnosis of MS in cases with initial diagnostic uncertainty. J Neurol Psychiatry 2012. [DOI: 10.1136/jnnp-2011-301993.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
56
|
Mistry N, Beitnes JO, Halvorsen S, Abdelnoor M, Hoffmann P, Kjeldsen SE, Smith G, Aakhus S, Bjornerheim R. Assessment of left ventricular function in ST-elevation myocardial infarction by global longitudinal strain: a comparison with ejection fraction, infarct size, and wall motion score index measured by non-invasive imaging modalities. EUROPEAN JOURNAL OF ECHOCARDIOGRAPHY 2011; 12:678-83. [DOI: 10.1093/ejechocard/jer113] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
57
|
Mistry N, Hou J, Ballard R, Feigenberg S, DˈSouza W. WE-G-214-06: Pulmonary Ventilation and Perfusion Imaging Using 4DCT. Med Phys 2011. [DOI: 10.1118/1.3613427] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
58
|
Zhang H, Mistry N, DˈSouza W. SU-E-T-273: Beyond Utilizing Functional Imaging for Contours and Visualization, Towards Physiological Radiotherapy to Improve Patient Outcome. Med Phys 2011. [DOI: 10.1118/1.3612224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
59
|
Mistry N, Bleetman A, Roberts KJ. Chest decompression during the resuscitation of patients in prehospital traumatic cardiac arrest. Emerg Med J 2011; 26:738-40. [PMID: 19773501 DOI: 10.1136/emj.2008.065599] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Tension and bilateral pneumothorax can cause or contribute to death following trauma. A surgical incision (thoracostomy) or needle decompression through the chest wall rapidly treats these conditions. Resuscitation of patients in traumatic cardiac arrest focuses on treating common and reversible life-threatening conditions. A study was undertaken to observe the practice, findings and outcome of chest decompression when performed as part of the resuscitation strategy of these patients by air ambulance crews. METHODS Patients in prehospital traumatic cardiac arrest were identified over a 39-month period from an air ambulance database. The use of thoracostomy or needle decompression was identified together with indications, findings and outcome. Primary outcome was return of cardiac output by arrival at hospital. RESULTS 18 of 37 cases underwent chest decompression (17 thoracostomy, 1 needle decompression). Four patients had a return of cardiac output (3 tension pneumothorax, 1 bilateral pneumothorax). Six further cases were positive for intrathoracic injury. In 2 cases the injuries identified were incompatible with life and resuscitation efforts were consequently ceased. CONCLUSIONS Chest decompression in traumatic cardiac arrest identifies and treats a high proportion of potentially life-ending injuries and should be considered as part of the resuscitation effort of patients in traumatic cardiac arrest. In a proportion of patients, non-survivable injuries are identified which guide resuscitation efforts.
Collapse
|
60
|
Cooke MS, Evans MD, Mistry N, Lunec J. Role of dietary antioxidants in the prevention of in vivo oxidative DNA damage. Nutr Res Rev 2009; 15:19-42. [PMID: 19087397 DOI: 10.1079/nrr200132] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Epidemiological evidence consistently shows that diets high in fresh fruit and vegetables significantly lower cancer risk. Given the postulated role of oxidative DNA damage in carcinogenesis, the assumption has been made that it is the antioxidant properties of food constituents, such as vitamin C, E and carotenoids, which confer protection. However, epidemiological studies with specific antioxidants, either singly or in combination, have not, on the whole, supported this hypothesis. In contrast, studies examining the in vitro effect of antioxidants upon oxidative DNA damage have generally been supportive, in terms of preventing damage induction. The same, however, cannot be said for the in vivo intervention studies where overall the results have been equivocal. Nevertheless, recent work has suggested that some dietary antioxidants may confer protective properties through a novel mechanism, unrelated to their conventional free-radical scavenging abilities. Upregulation of antioxidant defence, xenobiotic metabolism, or DNA-repair genes may all limit cellular damage and hence promote maintenance of cell integrity. However, until further work has clarified whether dietary supplementation with antioxidants confers a reduced risk of cancer and the mechanism by which this effect is exerted, the recommendation for a diet rich in fruit and vegetables remains valid empirically.
Collapse
|
61
|
|
62
|
Mistry N, Turner MR, Bogdanovic M, Nithi K, Cadoux-hudson T. A resistant case of spontaneous intracranial hypotension. Br J Neurosurg 2009; 22:705-8. [DOI: 10.1080/02688690802044068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
63
|
Mistry N, Foty R, Dell S, Stieb D, Parkin P. Determinants of Child Health: Children's Access to a Paediatrician. Paediatr Child Health 2009. [DOI: 10.1093/pch/14.suppl_a.24ab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
64
|
Misra A, Mistry N, Grimer R, Peart F. The management of soft tissue sarcoma. J Plast Reconstr Aesthet Surg 2008; 62:161-74. [PMID: 19036655 DOI: 10.1016/j.bjps.2008.08.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 07/14/2008] [Accepted: 08/12/2008] [Indexed: 11/19/2022]
Abstract
SUMMARY Soft tissue sarcomas are a rare group of mesenchymal tumours that display cardinal signs, which can raise suspicion to their diagnosis. Management in a sarcoma treatment centre by its multidisciplinary team has improved outcome. Good local disease control with limb salvage and adjuvant radiotherapy has considerably reduced the morbidity of previous limb amputation. By the early involvement of a plastic surgeon, tissue reconstruction is optimised and wound complications reduced. This article looks at the contemporary management of soft tissue sarcoma and, in particular, its relevance to the plastic surgeon today.
Collapse
|
65
|
Bansal RK, Mistry N, Kargathra V, Kosambi A, Lathiya P, Raval B. Unsupervised weight losing patterns by anorexic subjects: a cause for concern. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2008; 56:731-732. [PMID: 19086367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
|
66
|
Clingen PH, Wu JYH, Miller J, Mistry N, Chin F, Wynne P, Prise KM, Hartley JA. Histone H2AX phosphorylation as a molecular pharmacological marker for DNA interstrand crosslink cancer chemotherapy. Biochem Pharmacol 2008; 76:19-27. [PMID: 18508035 DOI: 10.1016/j.bcp.2008.03.025] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 03/27/2008] [Accepted: 03/28/2008] [Indexed: 11/25/2022]
Abstract
The aims of this study were to investigate mechanisms of action involved in H2AX phosphorylation by DNA interstrand crosslinking (ICL) agents and determine whether gammaH2AX could be a suitable pharmacological marker for identifying potential ICL cellular chemosensitivity. In normal human fibroblasts, after treatment with nitrogen mustard (HN2) or cisplatin, the peak gammaH2AX response was detected 2-3 h after the peak of DNA ICLs measured using the comet assay, a validated method for detecting ICLs in vitro or in clinical samples. Detection of gammaH2AX foci by immunofluorescence microscopy could be routinely detected with 6-10 times lower concentrations of both drugs compared to detection of ICLs using the comet assay. A major pathway for repairing DNA ICLs is the initial unhooking of the ICL by the ERCC1-XPF endonuclease followed by homologous recombination. HN2 or cisplatin-induced gammaH2AX foci persisted significantly longer in both, ERCC1 or XRCC3 (homologous recombination) defective Chinese hamster cells that are highly sensitive to cell killing by ICL agents compared to wild type or ionising radiation sensitive XRCC5 cells. An advantage of using gammaH2AX immunofluorescence over the comet assay is that it appears to detect ICL chemosensitivity in both ERCC1 and HR defective cells. With HN2 and cisplatin, gammaH2AX foci also persisted in chemosensitive human ovarian cancer cells (A2780) compared to chemoresistant (A2780cisR) cells. These results show that gammaH2AX can act as a highly sensitive and general marker of DNA damage induced by HN2 or cisplatin and shows promise for predicting potential cellular chemosensitivity to ICL agents.
Collapse
|
67
|
Mistry N, Hayter C, Poldre P, Henry M, Gardner S. 180 The impact of the Ivan H. Smith Memorial Studentship Program on career entry into radiation oncology. Radiother Oncol 2005. [DOI: 10.1016/s0167-8140(05)80341-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
68
|
Abstract
We describe the management of 40 cases of ectopic pregnancy and some of the difficulties encountered by trainees in using a laparoscopic approach.
Collapse
|
69
|
Danko I, Cronin-Hennessy D, Park C, Park W, Thayer J, Thorndike E, Coan T, Gao Y, Liu F, Stroynowski R, Artuso M, Boulahouache C, Blusk S, Dambasuren E, Dorjkhaidav O, Mountain R, Muramatsu H, Nandakumar R, Skwarnicki T, Stone S, Wang J, Mahmood A, Csorna S, Bonvicini G, Cinabro D, Dubrovin M, Bornheim A, Lipeles E, Pappas S, Shapiro A, Sun W, Weinstein A, Briere R, Chen G, Ferguson T, Tatishvili G, Vogel H, Watkins M, Adam N, Alexander J, Berkelman K, Boisvert V, Cassel D, Duboscq J, Ecklund K, Ehrlich R, Galik R, Gibbons L, Gittelman B, Gray S, Hartill D, Heltsley B, Hsu L, Jones C, Kandaswamy J, Kreinick D, Kuznetsov V, Magerkurth A, Mahlke-Krüger H, Meyer T, Mistry N, Patterson J, Pedlar T, Peterson D, Pivarski J, Richichi S, Riley D, Sadoff A, Schwarthoff H, Shepherd M, Thayer J, Urner D, Wilksen T, Warburton A, Weinberger M, Athar S, Avery P, Breva-Newell L, Potlia V, Stoeck H, Yelton J, Eisenstein B, Gollin G, Karliner I, Lowrey N, Plager C, Sedlack C, Selen M, Thaler J, Williams J, Edwards K, Besson D, Gao K, Gong D, Kubota Y, Li S, Poling R, Scott A, Smith A, Stepaniak C, Urheim J, Metreveli Z, Seth K, Tomaradze A, Zweber P, Ernst J, Arms K, Eckhart E, Gan K, Gwon C, Severini H, Skubic P, Dytman S, Mueller J, Nam S, Savinov V, Huang G, Miller D, Pavlunin V, Sanghi B, Shibata E, Shipsey I. Measurement of the decay rate of Ξc0→pK-K-π+ relative to Ξc0→Ξ-π+. Int J Clin Exp Med 2004. [DOI: 10.1103/physrevd.69.052004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
70
|
Mistry N, Cranmer SL, Yuan Y, Mangin P, Dopheide SM, Harper I, Giuliano S, Dunstan DE, Lanza F, Salem HH, Jackson SP. Cytoskeletal regulation of the platelet glycoprotein Ib/V/IX-von willebrand factor interaction. Blood 2000; 96:3480-9. [PMID: 11071645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
Shear-induced binding of von Willebrand factor (vWf) to the platelet glycoprotein (GP) Ib/V/IX complex plays a key role in initiating platelet adhesion and aggregation at sites of vascular injury. This study demonstrated that pretreating human platelets with inhibitors of actin polymerization, cytochalasin D or latrunculin B, dramatically enhances platelet aggregation induced by vWf. The effects of these inhibitors were specific to the vWf-GPIbalpha interaction because they enhanced vWf-induced aggregation of Glanzmann thrombasthenic platelets and Chinese hamster ovary (CHO) cells transfected with GPIb/V/IX. Moreover, cytochalasin D enhanced the extent of platelet aggregation induced by high shear stress (5000 s(-1)) and also lowered the shear threshold required to induce aggregation from 3000 s(-1) to as low as 500 s(-1). Studies of CHO cells expressing GPIbalpha cytoplasmic tail truncation mutants that failed to bind actin-binding protein-280 (deletion of residues 569-610 or 535-568) demonstrated that the linkage between GPIb and actin-binding protein-280 was not required for vWf-induced actin polymerization, but was critical for the enhancing effects of cytochalasin D on vWf-induced cell aggregation. Taken together, these studies suggest a fundamentally important role for the cytoskeleton in regulating the adhesive function of GPIb/V/IX.
Collapse
|
71
|
Lunec J, Herbert KE, Dickinson L, Evans M, Mistry N, Mistry P, Chauhan D, Capper G, Zheng Q. Development of a quality control material for the measurement of 8-oxo-7,8-dihydro-2'-deoxyguanosine, an in vivo marker of oxidative stress, and comparison of results from different laboratories. Free Radic Res 2000; 33 Suppl:S27-31. [PMID: 11191272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The measurement of 8-oxo-7,8-dihydro-2'-deoxyguanosine is an increasingly popular marker of in vivo oxidative damage to DNA. A random-sequence 21-mer oligonucleotide 5'-TCA GXC GTA CGT GAT CTC AGT-3' in which X was 8-oxo-guanine (8-oxo-G) was purified and accurate determination of the oxidised base was confirmed by a 32P-end labelling strategy. The lyophilised material was analysed for its absolute content of 8-oxo-dG by several major laboratories in Europe and one in Japan. Most laboratories using HPLC-ECD underestimated, while GC-MS-SIM overestimated the level of the lesion. HPLC-ECD measured the target value with greatest accuracy. The results also suggest that none of the procedures can accurately quantitate levels of 1 in 10(6) 8-oxo-(d)G in DNA.
Collapse
|
72
|
Cooke MS, Mistry N, Ladapo A, Herbert KE, Lunec J. Immunochemical quantitation of UV-induced oxidative and dimeric DNA damage to human keratinocytes. Free Radic Res 2000; 33:369-81. [PMID: 11022846 DOI: 10.1080/10715760000300911] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
There is growing evidence to suggest that solar radiation-induced, oxidative DNA damage may play an important role in skin carcinogenesis. Numerous methods have been developed to sensitively quantitate 8-oxo-2'deoxyguanosine (8-oxodG), a recognised biomarker of oxidative DNA damage. Immunoassays may represent a means by which the limitations of many techniques, principally derived from DNA extraction and sample workup, may be overcome. We report the evaluation of probes to thymine dimers and oxidative damage in UV-irradiated cells and the DNA derived therefrom. Thymine dimers were most readily recognised, irrespective of whether in situ in cells or in extracted DNA. However, using antibody-based detection the more subtle oxidative modifications required extraction and, in the case of 8-oxodG, denaturation of the DNA prior to successful recognition. In contrast, a recently described novel probe for 8-oxodG detection showed strong recognition in cells, although appearing unsuitable for use with extracted DNA. The probes were subsequently applied to examine the relative induction of lesions in cells following UV irradiation. Guanine-glyoxal lesions predominated over thymine dimers subsequent to UVB irradiation, whereas whilst oxidative lesions increased significantly following UVA irradiation, no induction of thymine dimers was seen. These data support the emerging importance of oxidative DNA damage in UV-induced carcinogenesis.
Collapse
|
73
|
Carty JL, Bevan R, Waller H, Mistry N, Cooke M, Lunec J, Griffiths HR. The effects of vitamin C supplementation on protein oxidation in healthy volunteers. Biochem Biophys Res Commun 2000; 273:729-35. [PMID: 10873672 DOI: 10.1006/bbrc.2000.3014] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have investigated vitamin C supplementation effects on immunoglobulin oxidation (carbonyls) and total plasma protein sulfhydryls in healthy human volunteers. After receiving placebo, plasma ascorbate and oxidation markers were unchanged. Following 5 weeks supplementation with vitamin C (400 mg/day), plasma ascorbate increased but no significant effect on protein oxidation was observed. At 10 and 15 weeks supplementation, carbonyl levels were significantly reduced (P < 0.01) in subjects with low baseline ascorbate (29.51 +/- 5.3 microM) but not in those with normal baseline ascorbate (51.81 +/- 2.3 microM). To eliminate any effect from seasonal variation in dietary antioxidant intake, a second phase was undertaken. Subjects on vitamin C for 15 weeks were randomly assigned to receive either placebo or vitamin C. No difference in plasma sulfhydryl content was observed. Subjects withdrawn from supplementation showed an increase in immunoglobulin carbonyl content (P < 0.01). This demonstrates that dietary vitamin C supplementation can reduce certain types of oxidative protein damage in subjects with low basal antioxidant.
Collapse
|
74
|
Jackson SP, Mistry N, Yuan Y. Platelets and the injured vessel wall-- "rolling into action": focus on glycoprotein Ib/V/IX and the platelet cytoskeleton. Trends Cardiovasc Med 2000; 10:192-7. [PMID: 11282294 DOI: 10.1016/s1050-1738(00)00062-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Blood platelets play a key role in maintaining the integrity of the vascular system through their ability to arrest bleeding (haemostasis) and promote repair of injured blood vessels. Considerable progress has been made in the last few years in our understanding of the adhesion mechanisms utilized by platelets to adhere to sites of vascular injury. Studies have helped define the precise role of von Willebrand factor (vWf), and its platelet receptor, glycoprotein (GP) Ib/V/IX, in initiating platelet-vessel wall and platelet-platelet adhesion contacts. In addition to its adhesive role, recent studies have highlighted the importance of GPIb/V/IX in regulating the cytoskeleton of platelets. GPIb/V/IX not only maintains the normal cytoskeletal architecture of resting platelets but also induces cytoskeletal reorganization following engagement of vWf. Somewhat surprisingly, the physical link between GPIb/V/IX and the membrane skeleton does not appear necessary for GPIb/V/IX-induced cytoskeletal reorganization. In contrast, this linkage appears critical for GPIb/V/IX to maintain cell adhesion under high shear and also for the ability of the cytoskeleton to exert negative regulatory effects on the GPIb-vWf interaction. Thus a complex functional relationship appears to exist between GPIb/V/IX and the membrane skeleton that goes well beyond preserving the normal cytoskeletal architecture of resting platelets.
Collapse
|
75
|
Dekker LV, Leitges M, Altschuler G, Mistry N, McDermott A, Roes J, Segal AW. Protein kinase C-beta contributes to NADPH oxidase activation in neutrophils. Biochem J 2000; 347 Pt 1:285-9. [PMID: 10727429 PMCID: PMC1220958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
We have analysed the involvement of the beta isotype of the protein kinase C (PKC) family in the activation of NADPH oxidase in primary neutrophils. Using immunofluorescence and cell fractionation, PKC-beta is shown to be recruited to the plasma membrane upon stimulation with phorbol ester and to the phagosomal membrane upon phagocytosis of IgG-coated particles (Fcgamma-receptor stimulus). The time course of recruitment is similar to that of NADPH oxidase activation by these stimuli. The PKC-beta specific inhibitor 379196 inhibits the response to PMA as well as to IgG-coated bacteria. Partial inhibition occurs between 10 and 100 nM of inhibitor, the concentration at which PKC-beta, but not other PKC isotypes, is targeted. Neutrophils isolated from a mouse that lacks PKC-beta also showed an inhibition of NADPH oxidase activation by PMA and IgG-coated particles. The level of inhibition is comparable to that achieved with 379196 in human neutrophils. Thus the PKC-beta isotype mediates activation of NADPH oxidase by PMA and by stimulation of Fcgamma receptors in neutrophils.
Collapse
|