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result(s) for
"Stepanova, Victoria"
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Central and Eastern European Migrants in the United Kingdom: A Scoping Review of the Reasons for Utilisation of Transnational Healthcare
by
Poppleton, Aaron
,
Ponsford, Ruth
,
Stepanova, Victoria
in
Academic staff
,
Alternative approaches
,
Archives & records
2024
Background An estimated 2.2 million people from Central and Eastern Europe (CEE) live in the United Kingdom. It has been documented that CEE migrants underutilise health services in the United Kingdom and, as an alternative, seek healthcare in their home country. However, reasons for seeking healthcare abroad are not always clear. This review aims to identify the reasons for the uptake of transnational healthcare among CEE migrants resident in the United Kingdom. Methods Informed by discussions with community members, medical stakeholders and academics, a systematic scoping review was undertaken following the nine‐stage Joanna Briggs Institute framework for scoping reviews. A search strategy with MeSH terms, where relevant, was used and adapted in five academic databases, two grey literature databases and Google Scholar. Included records encompassed four concepts: migration, CEE nationalities, UK nations and healthcare utilisation, which were written in English and published between May 2004 and 2022. Data from the literature were coded, grouped and organised into themes. Results A total of 16 publications fulfilled the inclusion criteria. There is evidence that some CEE migrants exclusively use healthcare services in the United Kingdom. However, many CEE migrants utilise healthcare both in the United Kingdom and their country of origin. Four themes were identified from the literature as to why migrants travelled to their country of origin for healthcare: cultural expectations of medical services, distrust in the UK NHS, barriers and transnational ties. Conclusion Push factors led CEE migrants to seek healthcare in their country of origin, facilitated by ongoing transnational ties. CEE migrants frequently combine visits to their country of origin with medical appointments. Utilising healthcare in their country of origin as opposed to the United Kingdom can result in fragmented and incomplete records of medications, medical tests and surgeries and risk of unnecessary treatments and complications. This review highlights the need for more targeted health outreach with CEE groups within the United Kingdom, as well as the need for further research on the impact of national events, for example, COVID‐19 and Brexit, on transnational healthcare‐seeking behaviours. Patient or Public Contribution The concept for this scoping review was informed by discussions with community members, medical professionals and academics, who identified it as a current issue. The results of this scoping review were discussed with healthcare stakeholders.
Journal Article
Functional NMDA receptors are expressed by human pulmonary artery smooth muscle cells
2021
N-methyl-
d
-aspartate (NMDA) receptors are widely expressed in the central nervous system. However, their presence and function at extraneuronal sites is less well characterized. In the present study, we examined the expression of NMDA receptor subunit mRNA and protein in human pulmonary artery (HPA) by quantitative polymerase chain reaction (PCR), immunohistochemistry and immunoblotting. We demonstrate that both GluN1 and GluN2 subunit mRNAs are expressed in HPA. In addition, GluN1 and GluN2 (A–D) subunit proteins are expressed by human pulmonary artery smooth muscle cells (HPASMCs) in vitro and in vivo. These subunits localize on the surface of HPASMCs and form functional ion channels as evidenced by whole-cell patch-clamp electrophysiology and reduced phenylephrine-induced contractile responsiveness of human pulmonary artery by the NMDA receptor antagonist MK801 under hypoxic condition. HPASMCs also express high levels of serine racemase and vesicular glutamate transporter 1, suggesting a potential source of endogenous agonists for NMDA receptor activation. Our findings show HPASMCs express functional NMDA receptors in line with their effect on pulmonary vasoconstriction, and thereby suggest a novel therapeutic target for pharmacological modulations in settings associated with pulmonary vascular dysfunction.
Journal Article
Urokinase Gene Transfer Augments Angiogenesis in Ischemic Skeletal and Myocardial Muscle
by
Traktuev, Dmitry O
,
Stepanova, Victoria V
,
Parfyonova, Yelena V
in
Angiogenesis
,
Animals
,
Blood vessels
2007
Urokinase plasminogen activator (uPA) is required for both endogenous and vascular endothelial growth factor (VEGF)–augmented angiogenesis in normal tissues, leading us to hypothesize that uPA augmentation by gene transfer might promote angiogenesis in ischemic tissues. Overexpression of uPA was studied in rat myocardial infarction (MI) and mouse hind limb ischemia models and compared with VEGF overexpression effects. Animals were divided into control and three experimental groups (n = 6), receiving intramuscular injections of plasmids as follows: (i) control (empty vector or expressing β‐galactosidase); (ii) uPA; (iii) VEGF165; (iv) a 1:1 mixture of uPA and VEGF165. The capillary densities in both ischemic models were greater (P < 0.05) in tissues treated with uPA, VEGF, or a combination of both than in controls. Infarct size was reduced in hearts from uPA and VEGF experimental groups compared with controls (P < 0.05). Local overexpression of uPA induced a marked increase in the number of macrophages and myofibroblasts present within infarcts. Hind limb blood flow was greater in all experimental groups by day 10 (P < 0.05). Overall, the effects of uPA and VEGF were uniformly comparable. Additional analysis revealed association of local edema with VEGF but not with uPA treatment. This study established that uPA gene therapy effectively induces functionally significant angiogenesis in models of acute MI and hind limb ischemia.
Journal Article
Stat1 Nuclear Translocation by Nucleolin upon Monocyte Differentiation
by
Dietz, Rainer
,
Hinz, Michael
,
Tkachuk, Sergey
in
Active Transport, Cell Nucleus
,
Animals
,
Apoptosis
2009
Members of the signal transducer and activator of transcription (Stat) family of transcription factors traverse the nuclear membrane through a specialized structure, called the nuclear pore complex (NPC), which represents a selective filter for the import of proteins. Karyophilic molecules can bind directly to a subset of proteins of the NPC, collectively called nucleoporins. Alternatively, the transport is mediated via a carrier molecule belonging to the importin/karyopherin superfamily, which transmits the import into the nucleus through the NPC.
In this study, we provide evidence for an alternative Stat1 nuclear import mechanism, which is mediated by the shuttle protein nucleolin. We observed Stat1-nucleolin association, nuclear translocation and specific binding to the regulatory DNA element GAS. Using expression of nucleolin transgenes, we found that the nuclear localization signal (NLS) of nucleolin is responsible for Stat1 nuclear translocation. We show that this mechanism is utilized upon differentiation of myeloid cells and is specific for the differentiation step from monocytes to macrophages.
Our data add the nucleolin-Stat1 complex as a novel functional partner for the cell differentiation program, which is uniquely poised to regulate the transcription machinery via Stat1 and nuclear metabolism via nucleolin.
Journal Article
Halfdan Mahler: Architect and Defender of the World Health Organization “Health for All by 2000” Declaration of 1978
by
Stepanova, Victoria
,
Brown, Theodore M.
,
Fee, Elizabeth
in
AJPH History
,
Charisma
,
Congresses as Topic - history
2016
The adoption of the Declaration of Alma-Ata in September 1978 was one of the shining moments in public health history. Secretary-General Halfdan Mahler of the WHO was the charismatic driving force behind the declaration.
Journal Article
Urokinase Plasminogen Activator in Injured Adventitia Increases the Number of Myofibroblasts and Augments Early Proliferation
by
Ratner, Elizaveta I.
,
Tkachuk, Vsevolod A.
,
Plekhanova, Olga S.
in
Animals
,
Carotid Artery Injuries - pathology
,
Carotid Artery, Common - pathology
2006
Myofibroblasts are involved in vessel remodeling during the development of hypertension as well as after angioplasty and aortocoronary grafting, but the mechanisms of myofibroblastic phenotypic modulation are not fully elucidated. We assessed the role of urokinase plasminogen activator (uPA) and its proteolytic activity in myofibroblast differentiation and the early proliferation following mechanical injury of the rat carotid adventitia. The effects of perivascular application of recombinant uPA (r-uPA), proteolytically inactive r-uPA(H/Q) and uPA neutralizing antibody were evaluated 4 days after surgical injury to the adventitia. The phenotype of adventitial cells was assessed using anti-α-smooth muscle actin (α-SM actin) antibody, anti-SM heavy chain myosin, anti-high-molecular-weight caldesmon, anti-smoothelin and anti-ED-1 antibodies, proliferation by the expression of proliferating cell nuclear antigen, and the size of the adventitia by quantitative morphometry. Four days after injury, the intensive immunostaining for urokinase appeared in the rat carotid artery adventitia. At the same time, the frequency of α-SM actin-positive adventitial cells was 1.8 ± 1.1% in uninjured arteries and 25.2 ± 5.4% in injured arteries (p < 0.05), and the respective frequency of ED-1-positive cells 1.5 ± 1.1 and 25.0 ± 5.2%. The application of exogenous r-uPA doubled the numbers of α-SM actin-positive adventitial cells to 55.7 ± 6.8% (p < 0.05). ED-1-positive cells and proliferating cell nuclear antigen-positive cells as well as the size of the adventitia were also significantly increased after r-uPA compared with injury alone. In contrast, the proteolytically inactive r-uPA(H/Q) did not affect any parameters. The application of uPA neutralizing antibody attenuated the frequency of α-SM actin-positive cells to 12.6 ± 3.5% (p < 0.05), the frequency of ED-1-positive cells, and the numbers of adventitial cells. r-uPA stimulation of cultured human skin fibroblasts significantly increased the α-SM actin content in a concentration-dependent manner. In contrast, r-uPA(H/Q) did not induce changes in α-SM actin content. We conclude that uPA, which is upregulated in the injured adventitia, can augment adventitial cell accumulation, including myofibroblasts, and adventitia growth early after injury of the rat carotid artery adventitia by mechanisms involving proteolysis.
Journal Article
A chimeric platelet-targeted urokinase prodrug selectively blocks new thrombus formation
by
Fuentes, Rudy E.
,
Lambert, Michele P.
,
Aster, Richard H.
in
Animals
,
Biomedical research
,
Blood clot
2016
The use of fibrinolytic agents to prevent new thrombus formation is limited by an increased risk of bleeding due to lysis of hemostatic clots that prevent hemorrhage in damaged blood vessels. We sought to develop an agent that provides thromboprophylaxis without carrying a significant risk of causing systemic fibrinolysis or disrupting hemostatic clots. We previously showed that platelet (PLT) α granule-delivered urokinase plasminogen activator (uPA) is highly effective in preventing thrombosis, while being associated with little systemic fibrinolysis or bleeding. Here, we generated a chimeric prodrug composed of a single-chain version of the variable region of an anti-αIIbβ3 mAb fused to a thrombin-activatable, low-molecular-weight pro-uPA (PLT/uPA-T). PLT/uPA-T recognizes human αIIbβ3 on both quiescent and activated platelets and is enzymatically activated specifically by thrombin. We found that this prodrug binds tightly to human platelets even after gel filtration, has a prolonged half-life in mice transgenic for human αIIb compared with that of uPA-T, and prevents clot formation in a microfluidic system. Importantly, in two murine injury models, PLT/uPA-T did not lyse preexisting clots, even when administration was delayed by as little as 10 minutes, while it concurrently prevented the development of nascent thrombi. Thus, PLT/uPA-T represents the prototype of a platelet-targeted thromboprophylactic agent that selectively targets nascent over preexisting thrombi.
Journal Article
A chimeric platelet-targeted urokinase prodrug selectively blocks new thrombus formation
by
Muzykantov, Vladimir R
,
Cines, Douglas B
,
Stepanova, Victoria
in
Blood clot
,
Health aspects
,
Methods
2016
The use of fibrinolytic agents to prevent new thrombus formation is limited by an increased risk of bleeding due to lysis of hemostatic clots that prevent hemorrhage in damaged blood vessels. We sought to develop an agent that provides Thrombo prophylaxis without carrying a significant risk of causing systemic fibrinolysis or disrupting hemostatic clots. We previously showed that platelet (PLT) α granule-delivered urokinase plasminogen activator (uPA) is highly effective in preventing thrombosis, while being associated with little systemic fibrinolysis or bleeding. Here, we generated a chimeric prodrug composed of a single-chain version of the variable region of an anti-αIIbβ3 mAb fused to a thrombin-activatable, low-molecular-weight pro-uPA (PLT/uPA-T). PLT/uPA-T recognizes human αIIbβ3 on both quiescent and activated platelets and is enzymatically activated specifically by thrombin. We found that this prodrug binds tightly to human platelets even after gel filtration, has a prolonged half-life in mice transgenic for human aIIb compared with that of uPA-T, and prevents clot formation in a microfluidic system. Importantly, in two murine injury models, PLT/uPA-T did not lyse preexisting clots, even when administration was delayed by as little as 10 minutes, while it concurrently prevented the development of nascent thrombi. Thus, PLT/uPA-T represents the prototype of a platelet-targeted thromboprophylactic agent that selectively targets nascent over preexisting thrombi.
Journal Article
Urokinase Induces Matrix Metalloproteinase-9/Gelatinase B Expression in THP-1 Monocytes via ERK1/2 and Cytosolic Phospholipase A2 Activation and Eicosanoid Production
by
Plakida, Karina
,
Elizarova, Eugenia
,
Vorotnikov, Alexander
in
Adenovirus
,
Cell Line
,
Cell Movement - physiology
2006
Objective: Urokinase-type plasminogen activator (uPA) regulates cell migration and invasion by pericellular proteolysis and signal transduction events. We characterized the mechanisms by which uPA regulates matrix metalloproteinase-9 (MMP9) function in THP-1 monocytes. Methods and Results: In THP-1 monocytes, MMP9 production induced by urokinase was completely inhibited by the ERK1/2 inhibitor, PD98059, but not by the p38 mitogen-activated protein kinase inhibitor, SB202190. A dominant negative MEK1 adenovirus also blocked MMP9 expression. The effect of urokinase was completely suppressed by genistein and by herbimycin A indicating that tyrosine kinase(s) are required for MMP9 production. Bisindolylmaleimide, a protein kinase C (PKC) inhibitor, did not decrease MMP9 expression suggesting that PKC activation is not required. Key roles for cytosolic phospholipase A 2 (PLA2) and eicosanoid production were shown by complete inhibition with methyl arachidonyl fluorophosphonate (an inhibitor of cytosolic PLA2), and indomethacin (a cyclooxygenase inhibitor), with no effect of monoalide, a secretory PLA2 inhibitor. uPA stimulated phosphorylation of cytosolic PLA2. Conclusions: Induction of MMP9 by uPA in THP-1 monocytes is via a pathway involving MEK1-ERK1/2-mediated activation of cytosolic PLA2 and eicosanoid generation. These data suggest important roles for eicosanoids in monocyte migration induced by uPA and MMP9.
Journal Article
Packaging of supplemented urokinase into naked alpha-granules of in vitro -grown megakaryocytes for targeted therapeutic delivery
2023
Our prior finding that uPA endogenously expressed and stored in the platelets of transgenic mice prevented thrombus formation without causing bleeding, prompted us to develop a potentially clinically relevant means of generating anti-thrombotic human platelets in vitro from CD34 + hematopoietic cell-derived megakaryocytes. CD34 + -megakaryocytes internalize and store in α-granules single-chain uPA (scuPA) and a uPA variant modified to be plasmin-resistant, but thrombin-activatable, (uPAT). Both uPAs co-localized with internalized factor V (FV), fibrinogen and plasminogen, low-density lipoprotein receptor-related protein 1 (LRP1), and interferon-induced transmembrane protein 3 (IFITM3), but not with endogenous von Willebrand factor (VWF). Endocytosis of uPA by CD34 + -\\megakaryocytes was mediated in part via LRP1 and αIIbβ3. scuPA-containing megakaryocytes degraded endocytosed intragranular FV, but not endogenous VWF, in the presence of internalized plasminogen, whereas uPAT-megakaryocytes did not significantly degrade either protein. We used a carotid-artery injury model in NOD-scid IL2rγnull (NSG) mice homozygous for VWF R1326H (a mutation switching binding VWF specificity from mouse to human glycoprotein IbmlIX) to test whether platelets derived from scuPA-MKs or uPAT-Mks would prevent thrombus formation. NSG/VWF R1326H mice exhibited a lower thrombotic burden after carotid artery injury compared to NSG mice unless infused with human platelets or MKs, whereas intravenous injection of either uPA-containing megakaryocytes into NSG/VWF R1326H generated sufficient uPA-containing human platelets to lyse nascent thrombi. These studies suggest the potential to deliver uPA or potentially other ectopic proteins within platelet α-granules from in vitro- generated megakaryocytes.Our prior finding that uPA endogenously expressed and stored in the platelets of transgenic mice prevented thrombus formation without causing bleeding, prompted us to develop a potentially clinically relevant means of generating anti-thrombotic human platelets in vitro from CD34 + hematopoietic cell-derived megakaryocytes. CD34 + -megakaryocytes internalize and store in α-granules single-chain uPA (scuPA) and a uPA variant modified to be plasmin-resistant, but thrombin-activatable, (uPAT). Both uPAs co-localized with internalized factor V (FV), fibrinogen and plasminogen, low-density lipoprotein receptor-related protein 1 (LRP1), and interferon-induced transmembrane protein 3 (IFITM3), but not with endogenous von Willebrand factor (VWF). Endocytosis of uPA by CD34 + -\\megakaryocytes was mediated in part via LRP1 and αIIbβ3. scuPA-containing megakaryocytes degraded endocytosed intragranular FV, but not endogenous VWF, in the presence of internalized plasminogen, whereas uPAT-megakaryocytes did not significantly degrade either protein. We used a carotid-artery injury model in NOD-scid IL2rγnull (NSG) mice homozygous for VWF R1326H (a mutation switching binding VWF specificity from mouse to human glycoprotein IbmlIX) to test whether platelets derived from scuPA-MKs or uPAT-Mks would prevent thrombus formation. NSG/VWF R1326H mice exhibited a lower thrombotic burden after carotid artery injury compared to NSG mice unless infused with human platelets or MKs, whereas intravenous injection of either uPA-containing megakaryocytes into NSG/VWF R1326H generated sufficient uPA-containing human platelets to lyse nascent thrombi. These studies suggest the potential to deliver uPA or potentially other ectopic proteins within platelet α-granules from in vitro- generated megakaryocytes.Unlike platelets, in vitro-grown megakaryocytes can store exogenous uPA in its α-granules.uPA uptake involves LRP1 and αIIbβ3 receptors and is functionally available from activated platelets.Key pointsUnlike platelets, in vitro-grown megakaryocytes can store exogenous uPA in its α-granules.uPA uptake involves LRP1 and αIIbβ3 receptors and is functionally available from activated platelets.
Journal Article