107 research outputs found

    SLT-VEGF Reduces Lung Metastases, Decreases Tumor Recurrence, and Improves Survival in an Orthotopic Melanoma Model

    Get PDF
    SLT-VEGF is a recombinant cytotoxin comprised of Shiga-like toxin (SLT) subunit A fused to human vascular endothelial growth factor (VEGF). It is highly cytotoxic to tumor endothelial cells overexpressing VEGF receptor-2 (VEGFR-2/KDR/Flk1) and inhibits the growth of primary tumors in subcutaneous models of breast and prostate cancer and inhibits metastatic dissemination in orthotopic models of pancreatic cancer. We examined the efficacy of SLT-VEGF in limiting tumor growth and metastasis in an orthotopic melanoma model, using NCR athymic nude mice inoculated with highly metastatic Line IV Cl 1 cultured human melanoma cells. Twice weekly injections of SLT-VEGF were started when tumors became palpable at one week after intradermal injection of 1 × 106 cells/mouse. Despite selective depletion of VEGFR-2 overexpressing endothelial cells from the tumor vasculature, SLT-VEGF treatment did not affect tumor growth. However, after primary tumors were removed, continued SLT-VEGF treatment led to fewer tumor recurrences (p = 0.007), reduced the incidence of lung metastasis (p = 0.038), and improved survival (p = 0.002). These results suggest that SLT-VEGF is effective at the very early stages of tumor development, when selective killing of VEGFR-2 overexpressing endothelial cells can still prevent further progression. We hypothesize that SLT-VEGF could be a promising adjuvant therapy to inhibit or prevent outgrowth of metastatic foci after excision of aggressive primary melanoma lesions

    Targeted scVEGF/(177)Lu radiopharmaceutical inhibits growth of metastases and can be effectively combined with chemotherapy

    Get PDF
    BACKGROUND: scVEGF/(177)Lu is a novel radiopharmaceutical targeted by recombinant single-chain (sc) derivative of vascular endothelial growth factor (VEGF) that binds to and is internalized by vascular endothelial growth factor receptors (VEGFR). scVEGF/(177)Lu potential as adjuvant and neoadjuvant anti-angiogenic therapy was assessed in metastatic and orthotopic mouse models of triple-negative breast cancer. METHODS: Metastatic lesions in Balb/c mice were established by intracardiac injection of luciferase-expressing 4T1luc mouse breast carcinoma cells. Mice with metastatic lesions received single intravenous (i.v.) injection of well-tolerated dose of scVEGF/(177)Lu (7.4 MBq/mouse) at day 8 after 4T1luc cell injection. Primary orthotopic breast tumors in immunodeficient mice were established by injecting luciferase-expressing MDA231luc human breast carcinoma cells into mammary fat pad. Tumor-bearing mice were treated with single injections of scVEGF/(177)Lu (7.4 MBq/mouse, i.v), or liposomal doxorubicin (Doxil, 1 mg doxorubicin per kg, i.v.), or with a combination of Doxil and scVEGF/(177)Lu given at the same doses, but two hours apart. Cold scVEGF-targeting conjugate was included in controls and in Doxil alone group. The effects of treatments were defined by bioluminescent imaging (BLI), computed tomography (CT), computed microtomography (microCT), measurements of primary tumor growth, and immunohistochemical analysis. RESULTS: In metastatic model, adjuvant treatment with scVEGF/(177)Lu decreased overall metastatic burden and improved survival. In orthotopic primary tumor model, a combination of Doxil and scVEGF/(177)Lu was more efficient in tumor growth inhibition than each treatment alone. scVEGF/(177)Lu treatment decreased immunostaining for VEGFR-1, VEGFR-2, and pro-tumorigenic M2-type macrophage marker CD206. CONCLUSIONS: Selective targeting of VEGFR with well-tolerated doses of scVEGF/(177)Lu is effective in metastatic and primary breast cancer models and can be combined with chemotherapy. As high level of VEGFR expression is a common feature in a variety of cancers, targeted delivery of (177)Lu for specific receptor-mediated uptake warrants further exploration

    The ARV roll out and the disability grant: a South African dilemma?

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Prior to the antiretroviral (ARV) drug roll out in 2004, people living with HIV (PLHIV) in South Africa received disability grants when they were defined as "AIDS-sick". In the absence of available and effective medication, a diagnosis of AIDS portended disability. The disability grant is a critical component of South Africa's social security system, and plays an important role in addressing poverty among PLHIV. Given the prevalence of unemployment and poverty, disability grants ensure access to essential resources, like food, for PLHIV. Following the ARV roll out in South Africa, PLHIV experienced improved health that, in turn, affected their grant eligibility. Our aim is to explore whether PLHIV reduced or stopped treatment to remain eligible for the disability grant from the perspectives of both PLHIV and their doctors.</p> <p>Methods</p> <p>A mixed-methods design with concurrent triangulation was applied. We conducted: (1) in-depth semi-structured interviews with 29 PLHIV; (2) in-depth semi-structured interviews with eight medical doctors working in the public sector throughout the Cape Peninsula; (3) three focus group discussions with programme managers, stakeholders and community workers; and (4) a panel survey of 216 PLHIV receiving ARVs.</p> <p>Results</p> <p>Unemployment and poverty were the primary concerns for PLHIV and the disability grant was viewed as a temporary way out of this vicious cycle. Although loss of the disability grant significantly affected the well-being of PLHIV, they did not discontinue ARVs. However, in a number of subtle ways, PLHIV "tipped the scales" to lower the CD4 count without stopping ARVs completely. Grant criteria were deemed ad hoc, and doctors struggled to balance economic and physical welfare when assessing eligibility.</p> <p>Conclusions</p> <p>It is crucial to provide sustainable economic support in conjunction with ARVs in order to make "positive living" a reality for PLHIV. A chronic illness grant, a basic income grant or an unemployment grant could provide viable alternatives when the PLHIV are no longer eligible for a disability grant.</p

    Imaging VEGF receptor expression to identify accelerated atherosclerosis

    Get PDF
    Background: The biology of the vulnerable plaque includes increased inflammation and rapid growth of vasa vasorum, processes that are associated with enhanced vascular endothelial growth factor (VEGF)/ imaging receptors for VEGF (VEGFR) signaling and are accelerated in diabetes. This study was designed to test the hypothesis that VEGFRs in atherosclerotic plaques with a SPECT tracer scVEGF-PEG-DOTA/99mTc (scV/Tc) can identify accelerated atherosclerosis in diabetes. Methods: Male apolipoprotein E null (ApoE−/−) mice (6 weeks of age) were made diabetic (n = 10) or left as non-diabetic (n = 13). At 26 to 28 weeks of age, 5 non-diabetic mice were injected with functionally inactivated scV/Tc (in-scV/Tc) that does not bind to VEGF receptors, while 8 non-diabetic and 10 diabetic mice were injected with scV/Tc. After blood pool clearance, at 3 to 4 h post-injection, mice were injected with CT contrast agent and underwent SPECT/CT imaging. From the scans, regions of interest (ROI) were drawn on serial transverse sections comprising the proximal aorta and the percentage of injected dose (%ID) in ROIs was calculated. At the completion of imaging, mice were euthanized, proximal aorta explanted for gamma well counting to determine the percentage of injected dose per gram (%ID/g) uptake and immunohistochemical characterization. Results: The uptake of scV/Tc in the proximal aorta, calculated from SPECT/CT co-registered scans as %ID, was significantly higher in the diabetic mice (0.036  ± 0.017%ID) compared to non-diabetic mice (0.017  ± 0.005%ID; P  < 0.01), as was uptake measured as %ID/g in harvested aorta, 1.81  ± 0.50%ID/g in the diabetic group vs. 0.98  ± 0.25%ID/g in the non-diabetic group (P  < 0.01). The nonspecific uptake of in-scV/Tc in proximal aorta was significantly lower than the uptake of functionally active scV/Tc. Immunostaining of the atherosclerotic lesions showed higher expression of VEGFR-1 and VEGFR-2 in the diabetic mice. Conclusion: These initial results suggest that imaging VEGFR with scV/Tc shows promise as a non-invasive approach to identify accelerated atherosclerosis

    Features of Marfan syndrome not listed in the Ghent nosology : the dark side of the disease

    Get PDF
    Introduction: The revised Ghent nosology presents the classical features of Marfan syndrome. However, behind its familiar face, Marfan syndrome hides less well-known features. Areas covered: The German Marfan Organization listed unusual symptoms and clinical experts reviewed the literature on clinical features of Marfan syndrome not listed in the Ghent nosology. Thereby we identified the following features: (1) bicuspid aortic valve, mitral valve prolapse, pulmonary valve prolapse, tricuspid valve prolapse, (2) heart failure and cardiomyopathy, (3) supraventricular arrhythmia, ventricular arrhythmia, and abnormal repolarization, (4) spontaneous coronary artery dissection, anomalous coronary arteries, and atherosclerotic coronary artery disease, tortuosity-, aneurysm-, and dissection of large and medium-sized arteries, (5) restrictive lung disease, parenchymal lung disease, and airway disorders, (6) obstructive- and central sleep apnea, (7) liver and kidney cysts, biliary tract disease, diaphragmatic hernia, and adiposity, (8) premature labor, and urinary incontinence, (9) myopathy, reduced bone mineral density, and craniofacial manifestations, (10) atrophic scars, (11) caries, and craniomandibular dysfunction, (12) headache from migraine and spontaneous cerebrospinal fluid leakage, (13) cognitive dysfunction, schizophrenia, depression, fatigue, and pain, (14) and activated fibrinolysis, thrombin, platelets, acquired von Willebrand disease, and platelet dysfunction. Expert commentary: Future research, nosologies, and guidelines may consider less well-known features of Marfan syndrome

    COVID-19 vaccination in patients receiving allergen immunotherapy (AIT) or biologicals:EAACI recommendations

    Get PDF
    Immune modulation is a key therapeutic approach for allergic diseases, asthma and autoimmunity. It can be achieved in an antigen-specific manner via allergen immunotherapy (AIT) or in an endotype-driven approach using biologicals that target the major pathways of the type 2 (T2) immune response: immunoglobulin (Ig)E, interleukin (IL)-5 and IL-4/IL-13 or non-type 2 response: anti-cytokine antibodies and B-cell depletion via anti-CD20. Coronavirus disease 2019 (COVID-19) vaccination provides an excellent opportunity to tackle the global pandemics and is currently being applied in an accelerated rhythm worldwide. The vaccine exerts its effects through immune modulation, induces and amplifies the response against the severe acute respiratory syndrome coronavirus (SARS-CoV-2). Thus, as there may be a discernible interference between these treatment modalities, recommendations on how they should be applied in sequence are expected. The European Academy of Allergy and Clinical Immunology (EAACI) assembled an expert panel under its Research and Outreach Committee (ROC). This expert panel evaluated the evidence and have formulated recommendations on the administration of COVID-19 vaccine in patients with allergic diseases and asthma receiving AIT or biologicals. The panel also formulated recommendations for COVID-19 vaccine in association with biologicals targeting the type 1 or type 3 immune response. In formulating recommendations, the panel evaluated the mechanisms of COVID-19 infection, of COVID-19 vaccine, of AIT and of biologicals and considered the data published for other anti-infectious vaccines administered concurrently with AIT or biologicals

    ENDOR Spectroscopy and DFT Calculations: Evidence for the Hydrogen-Bond Network Within α2 in the PCET of E. coli Ribonucleotide Reductase

    Get PDF
    Escherichia coli class I ribonucleotide reductase (RNR) catalyzes the conversion of nucleotides to deoxynucleotides and is composed of two subunits: α2 and β2. β2 contains a stable di-iron tyrosyl radical (Y[subscript 122]•) cofactor required to generate a thiyl radical (C[subscript 439]•) in α2 over a distance of 35 Å, which in turn initiates the chemistry of the reduction process. The radical transfer process is proposed to occur by proton-coupled electron transfer (PCET) via a specific pathway: Y[subscript 122] ⇆ W[subscript 48][?] ⇆ Y[subscript 356] in β2, across the subunit interface to Y[subscript 731] ⇆ Y[subscript 730] ⇆ C[subscript 439] in α2. Within α2 a colinear PCET model has been proposed. To obtain evidence for this model, 3-amino tyrosine (NH2Y) replaced Y[subscript 730] in α2, and this mutant was incubated with β2, cytidine 5′-diphosphate, and adenosine 5′-triphosphate to generate a NH2Y730• in D2O. [[superscript 2]H]-Electron–nuclear double resonance (ENDOR) spectra at 94 GHz of this intermediate were obtained, and together with DFT models of α2 and quantum chemical calculations allowed assignment of the prominent ENDOR features to two hydrogen bonds likely associated with C[subscript 439] and Y[subscript 731]. A third proton was assigned to a water molecule in close proximity (2.2 Å O–H···O distance) to residue 730. The calculations also suggest that the unusual g-values measured for NH[subscript 2]Y[subscript 730]• are consistent with the combined effect of the hydrogen bonds to Cys[subscript 439] and Tyr[subscript 731], both nearly perpendicular to the ring plane of NH[subscript 2]Y[subscript 730]. The results provide the first experimental evidence for the hydrogen-bond network between the pathway residues in α2 of the active RNR complex, for which no structural data are available.National Institutes of Health (U.S.) (NIH GM29595

    2019 ESC/EAS guidelines for the management of dyslipidaemias : Lipid modification to reduce cardiovascular risk

    Get PDF
    Correction: Volume: 292 Pages: 160-162 DOI: 10.1016/j.atherosclerosis.2019.11.020 Published: JAN 2020Peer reviewe

    ECMO for COVID-19 patients in Europe and Israel

    Get PDF
    Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients
    corecore