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Keshavarzi Z, Ashekar A, Vatanchian M, Abbaspour A, Bibak B, Behnamfar M, Barzegar S, Shakeri F. The effect of woody endocarpium of walnut alcoholic extract on acetic acid-induced ulcerative colitis in rats. BRAZ J PHARM SCI 2022. [DOI: 10.1590/s2175-97902022e19520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Zakieh Keshavarzi
- North Khorasan University of Medical Sciences, Iran; North Khorasan University of Medical Sciences, Iran
| | | | | | | | - Bahram Bibak
- North Khorasan University of Medical Sciences, Iran; North Khorasan University of Medical Sciences, Iran
| | | | | | - Farzaneh Shakeri
- North Khorasan University of Medical Sciences, Iran; North Khorasan University of Medical Sciences, Iran
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2
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Barzegar S, Asri Kojabad A, Manafi Shabestari R, Barati M, Rezvany MR, Safa M, Amani A, Pourfathollah A, Abbaspour A, Rahgoshay M, Hashemi J, Mohammadi Najafabadi M, Zaker F. Use of antioxidant nanoparticles to reduce oxidative stress in blood storage. Biotechnol Appl Biochem 2021; 69:1712-1722. [PMID: 34415072 DOI: 10.1002/bab.2240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 08/02/2021] [Indexed: 11/09/2022]
Abstract
Oxidative damage by free radicals has a negative effect on blood quality during storage. Antioxidant nanoparticles can prevent oxidative stress. We use SOD-CAT-Alb-PEG-PLGA- nanoparticles to reduce the effects of oxidative stress in blood storage. Electrospray was employed to prepare nanoparticles. Nanoparticles entered the test bags and were kept for 35 days from the time of donation under standard conditions. On target days, experiments were performed on the samples taken. The examination included blood smear, red blood cells count, hemoglobin, hematocrit, K, Fe, glutathione peroxidase, glutathion reductase, glucose-6-phosphate dehydrogenase, prooxidant-antioxidant balance, malondialdehyde, and flow cytometric assay for phosphatidylserine. The repeated measures analysis was performed on samples every week. Morphological changes were less in the test group compared to the control. The quantitative hemolysis profile test showed significant changes in the test and control groups (p < 0.05) in consecutive weeks except for K and Fe. Oxidative stress parameters too showed a significant change during the target days of the examination (p < 0.05). Also, the phosphatidylserine expression was increased in control groups more than test in consecutive weeks (p < 0.05). It seems that the use of antioxidant nanoparticles improves the quality of stored red blood cells and can prevent posttransfusion complications and blood loss by reducing oxidative stress.
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Affiliation(s)
- Saeid Barzegar
- Department of Pathobiology and laboratory sciences, School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran.,Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Amir Asri Kojabad
- Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Rima Manafi Shabestari
- Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Mehdi Barati
- Department of Immunology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Reza Rezvany
- Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran.,Pediatric Growth and Development Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran.,Department of Oncology-Pathology, Immune and Gene Therapy Lab, Cancer Center Karolinska, Karolinska University Hospital Solna and Karolinska Institute, Stockholm, Sweden
| | - Majid Safa
- Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Amir Amani
- Department of Biotechnology, School of Medicine, School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Aliakbar Pourfathollah
- Department of Immunology, School of Medicine, Tarbiat Modares University, Iranian Blood Transfusion Research Center, Tehran, Iran
| | - Alireza Abbaspour
- Department of Pathobiology and laboratory sciences, School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Mahsa Rahgoshay
- Department of Hematology, School of Allied Medical Sciences, Kerman University of Medical Sciences, Kerman, Iran
| | - Javad Hashemi
- Department of Pathobiology and laboratory sciences, School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | | | - Farhad Zaker
- Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
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Barzegar S, Rezvani MR, Safa M, Amani A, Abbaspour A, Pourfathollah A, Hashemi J, Zaker F. Dose-dependent efficacy of antioxidant nanoparticles on red blood cells storage. J Educ Health Promot 2021; 10:256. [PMID: 34485553 PMCID: PMC8395988 DOI: 10.4103/jehp.jehp_1638_20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 12/27/2020] [Indexed: 05/05/2023]
Abstract
BACKGROUND Transfusion of healthy red blood cells (RBCs) after storage is important. One of the storage lesions on blood bags is oxidative stress. One way to prevent increased oxidative stress is to use antioxidant nanoparticles (NPs). Superoxide dismutase (SOD) and catalase (CAT) play an important role in antioxidant defense on RBC. poly lactic-co-glycolic acid (PLGA) is a nontoxic biodegradable polymer that is approved by the Food and Drug Administration for drug delivery. This study aimed to assess dose-dependent efficacy of SOD-CAT-polyethylene glycol -PLGA on RBCs storage. MATERIALS AND METHODS Using a descriptive study, during 1 month, twenty donors from Bojnourd Blood Donation Center were selected. NPs with different concentrations were injected into the satellite bags after directing blood to them. On target days, experiments were performed on the samples taken. Electrospray was employed to prepare SOD-CAT-PLGA NPs. Twenty packed RBCs were isolated from the whole blood bags by the mechanical method, and certain amount of product was transferred to the satellite bags. On days 1, 7, 14, 21, 28, and 35, bags were sampled. Malondialdehyde (MDA), prooxidant-antioxidant balance (PAB), and Annexin V were performed on the samples taken. The repeated measures analysis with the help of SPSS software version 20 was performed on samples. RESULTS MDA increased in both groups. The maximum increase in test group was seen in concentration 12 mg (MDA Day 14, test [1.93 ± 0.3], [P MDA < 0.001]). Maximum increase in PAB was seen in concentration 12 mg (from 444 ± 1.7 to 563 ± 2.5) (P PAB = 0.000). Furthermore, PS expression increased in the concentration of 12 mg greater than other concentration in consecutive (from 5.00 ± 0.8 to 22.26 ± 1.7, [P < 0.001]). CONCLUSION Evaluation of dose dependency showed that different concentrations of antioxidant NPs affect RBC. This effect can be changed oxidative stress and apoptosis. Using both changes to evaluate functional and toxicity can be helpful.
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Affiliation(s)
- Saeid Barzegar
- Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Rezvani
- Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
- Pediatric Growth and Development Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran
- Department of Oncology-Pathology, Immune and Gene Therapy Lab, Cancer Center Karolinska, Karolinska University Hospital Solna and Karolinska Institute, Stockholm, Sweden
| | - Majid Safa
- Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Amir Amani
- Department of Biotechnology , School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Alireza Abbaspour
- Department of Pathobiology and Laboratory Sciences, School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Aliakbar Pourfathollah
- Department of Immunology, School of Medicine, Iranian Blood Transfusion Research Center, Tarbiat Modares University, Tehran, Iran
| | - Javad Hashemi
- Department of Pathobiology and Laboratory Sciences, School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Farhad Zaker
- Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
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Sedaghat M, Barzegar S, Niknam AR. Quasi-phase-matched laser wakefield acceleration of electrons in an axially density-modulated plasma channel. Sci Rep 2021; 11:15207. [PMID: 34312453 PMCID: PMC8313720 DOI: 10.1038/s41598-021-94751-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 07/15/2021] [Indexed: 11/20/2022] Open
Abstract
Quasi-phase matching in corrugated plasma channels has been proposed as a way to overcome the dephasing limitation in laser wakefield accelerators. In this study, the phase-lock dynamics of a relatively long electron bunch injected in an axially-modulated plasma waveguide is investigated by performing particle simulations. The main objective here is to obtain a better understanding of how the transverse and longitudinal components of the wakefield as well as the initial properties of the beam affect its evolution and qualities. The results indicate that the modulation of the electron beam generates trains of electron microbunches. It is shown that increasing the initial energy of the electron beam leads to a reduction in its final energy spread and produces a more collimated electron bunch. For larger bunch diameters, the final emittance of the electron beam increases due to the stronger experienced transverse forces and the larger diameter itself. Increasing the laser power improves the maximum energy gain of the electron beam. However, the stronger generated focusing and defocusing fields degrade the collimation of the bunch.
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Affiliation(s)
- M Sedaghat
- Laser and Plasma Research Institute, Shahid Beheshti University, 1983969411, Tehran, Iran
| | - S Barzegar
- Laser and Plasma Research Institute, Shahid Beheshti University, 1983969411, Tehran, Iran
| | - A R Niknam
- Laser and Plasma Research Institute, Shahid Beheshti University, 1983969411, Tehran, Iran.
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Amani A, Shamloo A, Barzegar S, Forouzandehmehr M. Effect of Material and Population on the Delivery of Nanoparticles to an Atherosclerotic Plaque: A Patient-specific In Silico Study. Langmuir 2021; 37:1551-1562. [PMID: 33465311 DOI: 10.1021/acs.langmuir.0c03158] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Coronary artery disease (CAD) is the prevalent reason of mortality all around the world. Targeting CAD, specifically atherosclerosis, with controlled delivery of micro and nanoparticles, as drug carriers, is a very proficient approach. In this work, a patient-specific and realistic model of an atherosclerotic plaque in the left anterior descending (LAD) artery was created by image-processing of CT-scan images and implementing a finite-element mesh. Next, a fluid-solid interaction simulation considering the physiological boundary conditions was conducted. By considering the simulated force fields and particle-particle interactions, the correlation between injected particles at each cardiac cycle and the surface density of adhered particles over the atherosclerotic plaque (SDP) were examined. For large particles (800 and 1000 nm) the amount of SDP on the plaque increased significantly when the number of the injected particles became higher. However, by increasing the number of the injected particles, for the larger particles (800 and 1000 nm) the increase in SDP was about 50% greater than that of the smaller ones (400 and 600 nm). Furthermore, for constant number of particles, depending on their size, different trends in SDP were observed. Subsequently, the distribution and adhesion of metal-based nanoparticles including SiO2, Fe3O4, NiO2, silver and gold with different properties were simulated. The injection of metal particles with medium density among the considered particles resulted in the highest SDP. Remarkably, the affinity, the geometrical features, and the biophysical factors involved in the adhesion outweighed the effect of difference in the density of particles on the SDP. Finally, the consideration of the lift force in the simulations significantly reduced the SDP and consistently decreased the particle residence time in the studied domain.
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Affiliation(s)
- Ali Amani
- School of Mechanical Engineering, Sharif University of Technology, Tehran 11155-9567, Iran
| | - Amir Shamloo
- School of Mechanical Engineering, Sharif University of Technology, Tehran 11155-9567, Iran
| | - Saeid Barzegar
- School of Mechanical Engineering, Sharif University of Technology, Tehran 11155-9567, Iran
| | - Mohamadamin Forouzandehmehr
- School of Mechanical Engineering, Sharif University of Technology, Tehran 11155-9567, Iran
- Faculty of Medicine and Health Technology, Tampere University, Tampere, FI-33520, Finland
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6
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Barzegar S, Wu SB, Noblet J, Choct M, Swick RA. Energy efficiency and net energy prediction of feed in laying hens. Poult Sci 2020; 98:5746-5758. [PMID: 31347669 DOI: 10.3382/ps/pez362] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 06/25/2019] [Indexed: 11/20/2022] Open
Abstract
Using accurate nutrient values for ingredients is of vital importance for efficient diet formulation. The net energy (NE) system accounts for the real available amount of feedstuff energy for body maintenance and production as it considers energy dissipated as heat increment. The NE content of diets for pigs and broilers has been estimated from their nutrient contents. However, such estimates have not been made specifically for laying hens. This study reports the development of equations to predict NE for laying hens based on the chemical composition of 16 different diets meeting minimum nutrient specifications but varying in nutrient composition. Heat production and energy metabolism were measured in layers ranging from 32 to 62 weeks of age in closed-circuit calorimetry chambers with 8 replicates per diet in a randomized design. Each replicate consisted of a chamber with 3 layers that were adapted for 4 D to diets and chambers prior to measurement. The measurements included feed intake, metabolizable energy (ME) content, nitrogen balance, egg production, gas exchange, heat production, energy efficiency, and energy partition for a 3-D period. The average AME/GE and NE/AME ratios of the 16 diets were 77 and 74%, respectively. The latter ratio increased with energy efficiency (EE) content and decreased with CP content of diets. The results indicate that diet NE content can be predicted from AME, CP, and EE contents and the NE/AME ratio varied positively with EE and negatively with CP. A validation experiment with 2 diets fed to layers in calorimetry chambers confirmed the estimation from NE prediction equations. In conclusion, NE of diets can be predicted in laying hens from equations based on AME and CP and EE contents in laying hens being similar to those reported in broilers.
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Affiliation(s)
- S Barzegar
- School of Environmental and Rural Science, University of New England, Armidale NSW 2351, Australia
| | - S-B Wu
- School of Environmental and Rural Science, University of New England, Armidale NSW 2351, Australia
| | - J Noblet
- INRA, UMR1348 Pegase, F-35590 Saint Gilles, France
| | - M Choct
- School of Environmental and Rural Science, University of New England, Armidale NSW 2351, Australia.,Poultry Cooperative Research Centre, University of New England, Armidale NSW 2351, Australia
| | - R A Swick
- School of Environmental and Rural Science, University of New England, Armidale NSW 2351, Australia
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7
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Miller GJ, Bauer KA, Barzegar S, Foley AJ, Mitchell JP, Cooper JA, Rosenberg RD. The Effects of Quality and Timing of Venepuncture on Markers of Blood Coagulation in Healthy Middle-aged Men. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1653729] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryEffects of the quality and the time of venepuncture on factor VII coagulant activity (VIIC) and the concentrations of fibrinogen, prothrombin fragment 1 + 2 (F1 + 2) and fibrinopeptide A (FPA) were sought in 2665 men, of whom 2334 were re-examined after about one year. Venepunctures were categorised as satisfactory, not fully satisfactory or unsatisfactory according to pre-defined criteria. Neither the quality nor timing of the venepuncture influenced VIICor fibrinogen concentration. However, at baseline and re-examination F1 + 2and FPA were increased on average by about 9% and 45% respectively when venepunctures were not fully satisfactory, and by about 11% and 100% when unsatisfactory. Plasma collected after 1500 h had slightly but significantly lower levels of F1 + 2and FPA than samples taken earlier, possibly due to circadian rhythm. The results emphasise the need for careful surveillance of the venepuncture procedure and the value of FPA when using F1+ 2as a marker of risk of thrombosis.
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Affiliation(s)
- G J Miller
- The Medical Research Council Epidemiology and Medical Care Unit, London, UK
| | - K A Bauer
- The Molecular Medicine Unit, Beth Israel Hospital, Boston, MA, USA
| | - S Barzegar
- The Molecular Medicine Unit, Beth Israel Hospital, Boston, MA, USA
| | - A J Foley
- The Medical Research Council Epidemiology and Medical Care Unit, London, UK
| | - J P Mitchell
- The Medical Research Council Epidemiology and Medical Care Unit, London, UK
| | - J A Cooper
- The Medical Research Council Epidemiology and Medical Care Unit, London, UK
| | - R D Rosenberg
- The Molecular Medicine Unit, Beth Israel Hospital, Boston, MA, USA
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8
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Shahinfar J, Keshavarzi Z, Ahmadi M, Barzegar S, Asieh G, Abbaspour A. Serum Oxidative Stress Markers in Patients with Senile Cataract and Healthy Controls. J Coll Physicians Surg Pak 2018; 28:448-451. [PMID: 29848421 DOI: 10.29271/jcpsp.2018.06.448] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 04/05/2018] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To investigate the role of oxidative stress in patients with senile cataract. STUDY DESIGN Case-control study. PLACE AND DURATION OF STUDY North Khorasan University of Medical Sciences, Bojnurd, Iran, from 2014 to 2015. METHODOLOGY Non-randomised sampling was conducted on 74 patients with senile cataract and 79 healthy people. The oxidative stress level, glutathione peroxidase (GPx) and superoxide dismutase (SOD) enzymes were measured in serum. The results were analysed using SPSS software and followed by t-test analysis. P<0.05 was considered to be significant. RESULTS The median activity of GPx and SOD antioxidant enzymes in patients with cataract, was higher than healthy people (p=0.018 and p<0.0001, respectively). Peroxide-antioxidant (PAB) levels in patients with cataract was significantly higher than in healthy people (p<0.0001). CONCLUSION This study showed that despite the high level of oxidative stress in patients, the activity rate of GPx and SOD enzymes also increased.
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Affiliation(s)
- Javad Shahinfar
- Department of Anesthesia, School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Zakieh Keshavarzi
- Natural Products and Medicinal Plants Research Center, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Mojgan Ahmadi
- Department of Biology, Payamnoor University, Mashhad, Iran
| | - Saeid Barzegar
- Department of Biochemistry and Hematology, School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Garivani Asieh
- School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Alireza Abbaspour
- Department of Biochemistry, School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran
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Barzegar S, Zamani AA, Abbasi S, Vafaei Shooshtari R, Shirvani Farsani N. Temperature-Dependent Development Modeling of the Phorid Fly Megaselia halterata (Wood) (Diptera: Phoridae). Neotrop Entomol 2016; 45:507-517. [PMID: 27147228 DOI: 10.1007/s13744-016-0400-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 04/05/2016] [Indexed: 06/05/2023]
Abstract
The effect of temperature on the development of Megaselia halterata (Wood) (Diptera: Phoridae) on A15 variety of button mushroom in the stages of casing and spawn-running was investigated at eight constant temperatures (10, 12.5, 15, 18, 20, 22.5, 25, and 27°C) and developmental rates were modeled as a function of temperature. At 25 and 27°C, an average of 22.2 ± 0.14 and 20.0 ± 0.10 days was needed for M. halterata to complete its development from oviposition to adult eclosion in the stages of casing and spawn-running, respectively. The developmental times of males or females at various constant temperatures were significantly different. Among the linear models, the Ikemoto and Takai linear model in the absence of 12.5 and 25°C showed the best statistical goodness-of-fit and based on this model, the lower developmental threshold and the thermal constant were estimated as 10.4°C and 526.3 degree-days, respectively. Twelve nonlinear temperature-dependent models were examined to find the best model to describe the relationship between temperature and development rate of M. halterata. The Logan 10 nonlinear model provided the best estimation for T opt and T max and is strongly recommended for the description of temperature-dependent development of M. halterata.
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Affiliation(s)
- S Barzegar
- Dept of Plant Protection, College of Agriculture, Razi Univ, Kermanshah, Iran
| | - A A Zamani
- Dept of Plant Protection, College of Agriculture, Razi Univ, Kermanshah, Iran.
| | - S Abbasi
- Dept of Plant Protection, College of Agriculture, Razi Univ, Kermanshah, Iran
| | - R Vafaei Shooshtari
- Dept of Agricultural Entomology, College of Agriculture, Islamic Azad Univ, Arak Branch, Arak, Iran
| | - N Shirvani Farsani
- Dept of Plant Protection, College of Agriculture, Razi Univ, Kermanshah, Iran
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10
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Barkhordari A, Barzegar S, Hekmatimoghaddam H, Jebali A, Rahimi Moghadam S, Khanjani N. The toxic effects of silver nanoparticles on blood mononuclear cells. Int J Occup Environ Med 2014; 5:164-8. [PMID: 25027045 PMCID: PMC7767596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 04/19/2014] [Indexed: 11/03/2022]
Abstract
BACKGROUND Nanoparticles have become one of the leading technologies over the past two years. The extensive use of nanoparticles has raised great concern about their occupational fate and biological effects. With an increase in the production and use of nanomaterial, it is more likely to get exposed to them occupationally and environmentally. OBJECTIVE To assess the toxicity of silver nanoparticles on human mononuclear cells. METHODS In this in vitro experimental study, suspensions of blood mononuclear cells from 10 young healthy men were incubated with 10-nm silver nanoparticles in different concentrations (range: 1-500 μg/mL) for 6 and 24 hours by MTT assay. Positive and negative controls were used for comparison. RESULTS After 6 hours of exposure, 10.9% to 48.4% of the cells died. After 24 hours of exposure, the rate ranged from 56.8% to 86.3%. Regardless of the exposure time, the maximum cytotoxicity was observed at the concentration of 500 μg/mL of silver nanoparticles. By increasing the exposure time to 24 hours, the cytotoxicity of nanoparticles substantially increased at all concentrations. Cell death was significantly higher when compared to the controls (p<0.01). CONCLUSION Silver nanoparticles possess both time- and dose-dependent cytotoxicity and can thus be considered as very toxic for mononuclear cells.
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Affiliation(s)
| | | | - H Hekmatimoghaddam
- 2Department of Pathology, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - A Jebali
- 3Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - S Rahimi Moghadam
- 4Department of Occupational Health, Neyshabur University of Medical Sciences, Neyshabur, Iran
| | - N Khanjani
- 5Department of Epidemiology and Biostatistics, Faculty of Health, Kerman University of Medical Sciences, Kerman, Iran
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Pourjavadi A, Ebrahimi A, Barzegar S. Preparation and evaluation of bioactive and compatible starch based superabsorbent for oral drug delivery systems. J Drug Deliv Sci Technol 2013. [DOI: 10.1016/s1773-2247(13)50074-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Shahinfar J, Fekri M, Ghafoori GF, Barzegar S, Ravaei D, Parandin R, Hakim M, Abbaspour A. Prooxidant–antioxidant balance in patients with cardiovascular disease. Clin Biochem 2011. [DOI: 10.1016/j.clinbiochem.2011.08.798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Ensafi AA, Hemmateenejad B, Barzegar S. Non-extraction flow injection determination of cationic surfactants using eriochrome black-T. Spectrochim Acta A Mol Biomol Spectrosc 2009; 73:794-798. [PMID: 19410502 DOI: 10.1016/j.saa.2009.03.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2008] [Revised: 03/08/2009] [Accepted: 03/19/2009] [Indexed: 05/27/2023]
Abstract
A new, rapid, sensitive, non-extraction batch, and flow injection spectrophotometric method for the determination of cationic surfactants (CSs) such as cetyltrimethyl ammonium bromide (CTAB), tetra-n-butyl ammonium chloride (TBAC) and cetylpyridinium chloride (CPC) is proposed. The method is based on the interaction of cationic surfactants with eriochrome black-T to form an ion-association complex. This complex has strong absorbance at 708 nm. The effects of chemical parameters and FIA variables on the determination of cationic surfactants were studied in detail, especially for CTAB. Under optimum conditions, the two linear calibration ranges of the method are 3.0 x 10(-6) to 5.0 x 10(-3)mol L(-1) CTAB, CPB and DTAB for the batch spectrophotometric method and 2.0 x 10(-6) to 2.0 x 10(-4)mol L(-1) CTAB, CPB and TBC for the flow injection spectrophotometric method. The sample throughput was 35+/-5 samples h(-1) at room temperature. The relative standard deviations for 10 replicates of analysis of (2.0, 0.6 and 0.2)x10(-4)mol L(-1) CTAB were 1.2, 1.3, and 0.8%, respectively. In addition, the influence of potential interfering substances on the determination of cationic surfactants was studied. The proposed method is simple and rapid, using no toxic organic solvents. It was applied to the determination of trace CS in industrial wastewater with satisfactory results.
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Affiliation(s)
- Ali A Ensafi
- Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
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Furie KL, Rosenberg R, Thompson JL, Bauer K, Mohr JP, Rosner B, Sciacca R, Barzegar S, Thornell B, Costigan T, Kistler JP. Thrombin generation in non-cardioembolic stroke subtypes: The Hemostatic System Activation Study. Neurology 2004; 63:777-84. [PMID: 15365123 DOI: 10.1212/01.wnl.0000137032.20456.df] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The association between hemostatic activation, stroke mechanism, and outcome is poorly defined. The Hemostatic System Activation Study (HAS) investigators measured serial levels of prothrombin fragment F1.2, a marker of thrombin generation, in patients enrolled in the Warfarin Aspirin Recurrent Stroke Study (WARSS). METHODS HAS enrolled 631 of the 2,206 patients in WARSS. Strokes were subtyped according to inferred mechanism. Plasma was collected for F1.2 at randomization (within 30 days of stroke), 3 months, 12 months, and 18 months. The 3 to 6 month samples in aspirin-treated patients were used for the primary analysis. RESULTS The authors analyzed 3 to 6 month samples on 320 patients. Higher F1.2 levels were associated with older age, female sex, and hypertension. There was no difference between mean F1.2 levels in 56 cryptogenic (0.9 +/- 0.32 nmol/L) and 114 non-cryptogenic (1.13 +/- 0.74 nmol/L) patients or across specific stroke subtypes. There was an 8.8%/year (p = 0.006) increase in mean F1.2 levels. There was a trend toward higher risk of recurrent stroke or death as F1.2 levels increased in aspirin (RR: 1.30, 95% CI: 0.57 to 2.94, p = 0.53) and warfarin treated patients (RR: 1.68, 95% CI: 0.48 to 5.94, p = 0.42). F1.2 levels were reduced on average 70% in warfarin-treated patients in a dose-dependent fashion. CONCLUSION F1.2 levels did not appear to differ by stroke subtype, suggesting that factors other than underlying stroke pathophysiology influence thrombin generation in the post-acute stroke period. F1.2 levels were suppressed by warfarin in a dose-dependent fashion. Additional research is needed to determine the predictive value of F1.2 after stroke.
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Affiliation(s)
- K L Furie
- V.B.K. 802, Stroke Service, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA.
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15
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Furie K, Thompson JLP, Bauer KA, Rosenberg R, Mohr JP, Rosner B, Sciacca R, Thornell BJ, Kelly PJ, Barzegar S, Lu Y, Kistler JP. Thrombin generation after ischemic stroke: the hemostatic system activation study (HAS). J Thromb Haemost 2003. [DOI: 10.1111/j.1538-7836.2003.tb04170.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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16
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Friederich PW, Levi M, Bauer KA, Vlasuk GP, Rote WE, Breederveld D, Keller T, Spataro M, Barzegar S, Büller HR. Ability of recombinant factor VIIa to generate thrombin during inhibition of tissue factor in human subjects. Circulation 2001; 103:2555-9. [PMID: 11382723 DOI: 10.1161/01.cir.103.21.2555] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND In view of the central role of the tissue factor-factor VIIa pathway in the initiation of blood coagulation, novel therapeutic strategies aimed at inhibiting this catalytic complex are currently being evaluated. A limitation of this new class of anticoagulants may be the lack of an appropriate strategy to reverse the effect if a bleeding event occurs. The aim of this study was to investigate the in vivo potential of recombinant factor VIIa (rVIIa) to induce thrombin generation in healthy subjects pretreated with recombinant nematode anticoagulant protein c2, a specific inhibitor of the tissue factor-factor VIIa complex, in a double-blind randomized crossover study. METHODS AND RESULTS Administration of nematode anticoagulant protein c2 (3.5 microgram/kg) caused a prolongation of the prothrombin time from 13.7+/-0.6 to 16.9+/-1.2 seconds. The subsequent injection of rVIIa (90 microgram/kg) resulted in an immediate and complete correction of the prothrombin time and a marked generation of thrombin, reflected by increased levels of prothrombin activation fragment F1+2 and thrombin-antithrombin complexes from 0.75+/-0.64 to 3.29+/-6.3 nmol/L and from 2.4+/-0.6 to 10.7+/-3.9 microgram/mL, respectively. Factor X and IX activation peptides showed a 3.5-fold and a 3.8-fold increase, respectively, after the administration of rVIIa in the presence of nematode anticoagulant protein c2. CONCLUSIONS During treatment with an inhibitor of the tissue factor-factor VIIa complex, the infusion of rVIIa resulted in thrombin generation. Our results indicate that rVIIa may be a good candidate as an antidote for inhibitors of tissue factor.
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Affiliation(s)
- P W Friederich
- Department of Vascular Medicine and Internal Medicine, Academic Medical Center, University of Amsterdam, Netherlands
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17
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Cooper JA, Miller GJ, Bauer KA, Morrissey JH, Meade TW, Howarth DJ, Barzegar S, Mitchell JP, Rosenberg RD. Comparison of novel hemostatic factors and conventional risk factors for prediction of coronary heart disease. Circulation 2000; 102:2816-22. [PMID: 11104738 DOI: 10.1161/01.cir.102.23.2816] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND This study sought to assess whether novel markers of hemostatic activity are predictive of coronary heart disease (CHD) and improve risk assessment. METHODS AND RESULTS Conventional CHD risk factors, the activation peptides of factor IX and factor X, factor VII activity and antigen, activated factor XII, prothrombin fragment 1+2, fibrinopeptide A, and fibrinogen were measured in 1153 men aged 50 to 61 years who were free of myocardial infarction at recruitment. Activated factor VII (VIIa) was measured in 829 men. During 7.8 years of follow-up, 104 had a CHD event. Baseline status was related to outcome by logistic regression by using a modified nested case-control design. Screening performance was judged from receiver operating characteristic curves. A high activated factor XII was associated with increased CHD risk, but low levels were not protective. Plasma VIIa and factor X activation peptide were independently and inversely related to risk. Plasma factor IX activation peptide and fibrinogen were positively associated with risk, but the relations were no longer statistically significant after adjustment for other factors, including VIIa and apoA-I. Other hemostatic markers were not associated with CHD risk. CONCLUSIONS Hemostatic status did not add significant predictive power to that provided by conventional CHD risk factors yet was able to substitute effectively for these factors.
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Affiliation(s)
- J A Cooper
- Medical Research Council, Epidemiology and Medical Care Unit, Wolfson Institute of Preventive Medicine, London, UK
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18
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Minnema MC, Peters RJ, de Winter R, Lubbers YP, Barzegar S, Bauer KA, Rosenberg RD, Hack CE, ten Cate H. Activation of clotting factors XI and IX in patients with acute myocardial infarction. Arterioscler Thromb Vasc Biol 2000; 20:2489-93. [PMID: 11073857 DOI: 10.1161/01.atv.20.11.2489] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In acute coronary events, plaque rupture and the subsequent formation of the catalytic tissue factor-factor VIIa complex is considered to initiate coagulation. It is unknown whether clotting factors XI and IX are activated in acute coronary events. Therefore, we prospectively investigated the activation of clotting factors XI and IX as well as activation of the contact system and the common pathway in 50 patients with acute myocardial infarction (AMI), in 50 patients with unstable angina pectoris (UAP), and in 50 patients with stable angina pectoris (SAP). Factor XIa-C1 inhibitor complexes, which reflect acute activation of factor XI, were detected in 24% of the patients with AMI, 8% of the patients with UAP, and 4% of the patients with SAP (P<0.05), whereas factor XIa-alpha(1)-antitrypsin complexes, which reflect chronic activation, were observed equally in all 3 study groups. Factor IX peptide levels were significantly higher in the patients with AMI and UAP compared with the patients with SAP (P<0.01). No differences regarding markers of the common pathway were demonstrated. Fibrinopeptide A levels were elevated in patients with AMI compared with patients with UAP and those with SAP (P<0.01). Factor XIIa- or kallikrein-C1 inhibitor complexes were not increased. In conclusion, this is the first demonstration of the activation of clotting factors XI and IX in patients with acute coronary syndromes. Because these clotting factors are considered to be important for continuous thrombin generation and clot stability, their activation might have clinical and therapeutic consequences.
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Affiliation(s)
- M C Minnema
- Department of Vascular Medicine, Academic Medical Center, Amsterdam, the Netherlands.
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19
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Bauer KA, Humphries S, Smillie B, Li L, Cooper JA, Barzegar S, Rosenberg RD, Miller GJ. Prothrombin activation is increased among asymptomatic carriers of the prothrombin G20210A and factor V Arg506Gln mutations. Thromb Haemost 2000; 84:396-400. [PMID: 11019961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The risk of venous thrombosis is increased in individuals who carry specific genetic abnormalities in blood coagulation proteins. Among Caucasians, the prothrombin G20210A and factor V Arg506Gln (FV R506Q) mutations are the most prevalent defects identified to date. We evaluated their influence on markers of coagulation activation among participants in the Second Northwick Park Heart Study, which recruited healthy men (aged 50-61 years) from nine general medical practices in England and Wales. They were free of clinical vascular disease and malignancy at the time of recruitment. Genotypes for the two mutations were analyzed using microplate array diagonal gel electrophoresis, and coagulation markers (factor XIIa; activation peptides of factor IX, factor X, and prothrombin; fibrinopeptide A) were measured by immunoassay. Factor VII coagulant activity and factor VIIa levels were determined by a functional clotting assay. Among 1548 men genotyped for both mutations, 28 (1.8%) and 52 (3.4%) were heterozygous for prothrombin G202 IOA and FV R506Q, respectively. The only coagulation marker that was significantly associated with the two mutations was prothrombin activation fragment FI+2 [mean +/- SD, 0.88 +/- 0.32 nmol/L in men with prothrombin G20210A (p = 0.002) and 0.89 +/- 0.30 in men with FV R506Q (p = 0.0001) versus 0.72 +/- 0.24 among non-carriers for either mutationl. This data provides conclusive evidence that heterozygosity for the prothrombin G20210A as well as the FV R506Q mutations in the general population leads to an increased rate of prothrombin activation in vivo.
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Affiliation(s)
- K A Bauer
- Department of Medicine, Beth Israel Deaconess Medical Center and Boston VA Healthcare System, Harvard Medical School, Boston, MA 02115, USA.
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20
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Miller GJ, Bauer KA, Barzegar S, Cooper JA, Rosenberg RD. Increased activation of the haemostatic system in men at high risk of fatal coronary heart disease. Thromb Haemost 1996; 75:767-71. [PMID: 8725721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The haemostatic system was examined in 2951 men aged 50 to 61 years, clinically free of cardiovascular disease, who were ranked according to a risk score for fatal coronary heart disease (CHD). Risk was judged from their serum cholesterol concentration, systolic blood pressure, body mass index and smoking habit. The status of the factor VII-tissue factor pathway was estimated from the plasma levels of factor VII coagulant activity, factor VII antigen and activated factor VII. Activation of factor IX was assessed from the plasma concentration of factor IX activation peptide. Activity within the common pathway was measured as the plasma concentrations of prothrombin fragment 1 + 2 and fibrinopeptide A. All 6 markers of haemostatic status were positively and statistically significantly associated with risk, providing further evidence for a hypercoagulable state in men at high risk for fatal CHD. Plasma fibrinogen and serum triglyceride concentrations were also graded positively with risk.
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Affiliation(s)
- G J Miller
- Medical Research Council Epidemiology, Medical College of St Bartholomew's Hospital, London, UK
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21
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ten Cate H, Biemond BJ, Levi M, Wuillemin WA, Bauer KA, Barzegar S, Buller HR, Hack CE, ten Cate JW, Rosenberg RD. Factor XIa induced activation of the intrinsic cascade in vivo. Thromb Haemost 1996; 75:445-9. [PMID: 8701405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Coagulation factor XI is a glycoprotein of the contact factor system. Its deficiency is associated with a highly variable bleeding tendency, thus a role in relation to hemostasis appears to exist. However, the importance of factor XI for stimulating intrinsic coagulation in vivo has not yet been determined. To study the procoagulant effects of human factor XIa in vivo, we infused the purified enzyme into normal chimpanzees (100 micrograms) in the absence or presence of the thrombin inhibitor rec-hirudin (1.0 mg/kg loading dose plus 0.3 mg/kg body wt continuous infusion). Factor XIa elicited an immediate activation of factors IX, X, and prothrombin, as measured by their respective activation fragments. However, whereas the activation of factors IX and X was immediate and shortlasting, (peak increments of 6- and 1.4-fold of baseline at 5 minutes after injection), the conversion of prothrombin gradually increased, reaching a summit of 6-fold baseline values after 60 min, and remaining elevated during the course of the experiments. Thrombin-antithrombin complexes also remained elevated during the study period. In the presence of hirudin, the initial activation of factors IX, X, and prothrombin was unchanged, however the further increment in prothrombin fragment F1 + 2 was markedly inhibited. These results demonstrate that factor XIa is a potential agonist of the intrinsic cascade in vivo, which activity is enhanced in the presence of thrombin.
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Affiliation(s)
- H ten Cate
- Dept. of Internal Medicine, Slotervaartziekenhuis, Amsterdam, The Netherlands
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22
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Miller GJ, Bauer KA, Barzegar S, Foley AJ, Mitchell JP, Cooper JA, Rosenberg RD. The effects of quality and timing of venepuncture on markers of blood coagulation in healthy middle-aged men. Thromb Haemost 1995; 73:82-6. [PMID: 7740501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Effects of the quality and the time of venepuncture on factor VII coagulant activity (VIIc) and the concentrations of fibrinogen, prothrombin fragment 1 + 2 (F1 + 2) and fibrinopeptide A (FPA) were sought in 2665 men, of whom 2334 were re-examined after about one year. Venepunctures were categorised as satisfactory, not fully satisfactory or unsatisfactory according to pre-defined criteria. Neither the quality nor timing of the venepuncture influenced VIIc or fibrinogen concentration. However, at baseline and re-examination F1 + 2 and FPA were increased on average by about 9% and 45% respectively when venepunctures were not fully satisfactory, and by about 11% and 100% when unsatisfactory. Plasma collected after 1500 h had slightly but significantly lower levels of F1 + 2 and FPA than samples taken earlier, possibly due to circadian rhythm. The results emphasise the need for careful surveillance of the venepuncture procedure and the value of FPA when using F1 + 2 as a marker of risk of thrombosis.
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Affiliation(s)
- G J Miller
- Medical Research Council Epidemiology and Medical Care Unit, London, UK
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23
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Mannucci PM, Bauer KA, Santagostino E, Faioni E, Barzegar S, Coppola R, Rosenberg RD. Activation of the coagulation cascade after infusion of a factor XI concentrate in congenitally deficient patients. Blood 1994; 84:1314-9. [PMID: 8049446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Virally inactivated, high-purity factor XI concentrates are available for treatment of patients with factor XI deficiency. However, preliminary experience indicates that some preparations may be thrombogenic. We evaluated whether a highly purified concentrate produced signs of activation of the coagulation cascade in two patients with severe factor XI deficiency infused before and after surgery. Signs of heightened enzymatic activity of the common pathway of coagulation (elevated plasma levels of prothrombin fragment 1 + 2 and fibrinopeptide A) developed in the early post-infusion period, accompanied by more delayed signs of fibrin formation with secondary hyperfibrinolysis (elevated D-dimer and plasmin-antiplasmin complex). These changes occurred in both patients, but were more severe in the older patient with breast cancer when she underwent surgery, being accompanied by fibrinogen and platelet consumption. There were no concomitant signs of heightened activity of the factor VII-tissue factor mechanism on the factor Xase complex (plasma levels of activated factor VII and of factor IX and X activation peptides did not increase). The observed changes in biochemical markers of coagulation activation indicate that concentrate infusions increased thrombin generation and activity and that such changes were magnified by malignancy and surgery. Because some factor XI concentrates may be thrombogenic, they should be used with caution, especially in patients with other risk factors for thrombosis.
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Affiliation(s)
- P M Mannucci
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Institute of Internal Medicine, IRCCS Maggiore Hospital, Milano, Italy
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24
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Kistler JP, Singer DE, Millenson MM, Bauer KA, Gress DR, Barzegar S, Hughes RA, Sheehan MA, Maraventano SW, Oertel LB. Effect of low-intensity warfarin anticoagulation on level of activity of the hemostatic system in patients with atrial fibrillation. BAATAF Investigators. Stroke 1993; 24:1360-5. [PMID: 8362431 DOI: 10.1161/01.str.24.9.1360] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND PURPOSE The Boston Area Anticoagulation Trial for Atrial Fibrillation (BAATAF) demonstrated that low-intensity warfarin anticoagulation can, with safety, sharply reduce the rate of stroke in patients with nonvalvular atrial fibrillation. The beneficial effect of warfarin was presumably related to a decrease in clot formation in the cardiac atria and subsequent embolization. METHODS To assess the effect of warfarin therapy on in vivo clotting in patients in the BAATAF, we measured the plasma level of prothrombin activation fragment F1+2. One sample was obtained from 125 patients from the BAATAF; 62 were taking warfarin and 63 were not taking warfarin (control group). RESULTS The warfarin group had a 71% lower mean F1+2 level than the control group (mean F1+2 of 1.57 nmol/L in the control group compared with a mean of 0.46 nmol/L in the warfarin group; P < .001). F1+2 levels were higher in older subjects but were consistently lower in the warfarin group at all ages. Fifty-two percent of patients in the control group were taking chronic aspirin therapy at the time their F1+2 level was measured. Control patients taking aspirin had F1+2 levels very similar to control patients not taking aspirin (mean of 1.52 nmol/L for control patients on aspirin compared with 1.64 nmol/L for control patients off aspirin; P > .1). CONCLUSIONS We conclude that prothrombin activation was significantly suppressed in vivo by warfarin but not aspirin among patients in the BAATAF. These findings correlate with the marked reduction in ischemic stroke noted among patients in the warfarin treatment group observed in the BAATAF.
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Affiliation(s)
- J P Kistler
- Neurology/Stroke Service, Massachusetts General Hospital, Boston 02114
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25
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ten Cate H, Bauer KA, Levi M, Edgington TS, Sublett RD, Barzegar S, Kass BL, Rosenberg RD. The activation of factor X and prothrombin by recombinant factor VIIa in vivo is mediated by tissue factor. J Clin Invest 1993; 92:1207-12. [PMID: 8376580 PMCID: PMC288259 DOI: 10.1172/jci116691] [Citation(s) in RCA: 152] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The human coagulation system continuously generates very small quantities of Factor Xa and thrombin. Current evidence suggests that basal level activation of the hemostatic mechanism occurs via Factor VIIa-dependent activation of Factor X, but direct proof has not been available for the participation of tissue factor in this pathway. To examine this issue, we infused relatively high concentrations of recombinant Factor VIIa (approximately 50 micrograms/kg body wt) into normal chimpanzees and observed significant increases in the plasma levels of Factor IX activation peptide, Factor X activation peptide, and prothrombin activation fragment F1+2. Metabolic turnover studies with radiolabeled Factor IX activation peptide, Factor X activation peptide, and F1+2 indicate that elevated levels of the activation peptides are due to accelerated conversion of the three coagulation system zymogens into serine proteases. The administration of a potent monoclonal antibody to tissue factor, which immediately neutralizes function of the Factor VIIa-tissue factor complex in vitro, abolishes the activation of Factor X and prothrombin mediated by the infused recombinant protein, and also suppresses basal level activation of Factor IX and Factor X. The above results suggest that recombinant Factor VIIa functions as a prohemostatic agent by interacting with endogenous tissue factor sites, but definitive proof will require studies in hemophilic animals using relevant hemostatic endpoints.
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Affiliation(s)
- H ten Cate
- Department of Internal Medicine, Slotervaart Hospital, Amsterdam, The Netherlands
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26
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Caine YG, Bauer KA, Barzegar S, ten Cate H, Sacks FM, Walsh BW, Schiff I, Rosenberg RD. Coagulation activation following estrogen administration to postmenopausal women. Thromb Haemost 1992; 68:392-5. [PMID: 1333098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We investigated coagulation system activation following estrogen treatment in 29 healthy postmenopausal women. Study participants received conjugated estrogens at 0.625 and 1.25 mg per day, and placebo for 3-month periods in a randomized crossover protocol. Blood samples were obtained on two consecutive days at the end of each treatment period for immunoassays of F1+2 and fibrinopeptide A (FPA), markers of factor Xa action on prothrombin and thrombin action on fibrinogen in vivo, respectively. Treatment with estrogens at a dose of 0.625 or 1.25 mg resulted in significant increases in mean F1+2 levels of 40 and 98%, respectively, and in mean FPA levels of 37 and 71%, respectively. The measurements of F1+2 were significantly higher in women receiving 1.25 mg of estrogen than 0.625 mg. We also observed significant declines in the levels of antithrombin III and total protein S antigen. Immunologic levels of protein C increased modestly at only the 1.25 mg estrogen dose level. These data indicate that low doses of oral estrogens (< or = 1.25 mg per day) frequently increase the amount of thrombin generated in vivo. Our observations may help to explain the increased thrombotic risk that has been observed with higher doses of this medication (> or = 2.5 mg).
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Affiliation(s)
- Y G Caine
- Department of Medicine, Beth Israel Hospital, Boston, MA
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27
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Wilkes HC, Meade TW, Barzegar S, Foley AJ, Hughes LO, Bauer KA, Rosenberg RD, Miller GJ. Gemfibrozil reduces plasma prothrombin fragment F1 + 2 concentration, a marker of coagulability, in patients with coronary heart disease. Thromb Haemost 1992; 67:503-6. [PMID: 1519208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effects of gemfibrozil on several indices of haemostatic activity were explored in male patients with coronary heart disease (CHD). Sixty-three of 71 patients completed a crossover study in which gemfibrozil 1,200 mg/day and matching placebo were each taken in randomised order for 2 months in a double-blind manner, separated by a 2-month washout period. Serum cholesterol decreased by an average (95% confidence interval) of 12 (9 to 15)% and non-fasting triglyceride concentration by 43 (34 to 51)% during active treatment. Plasma prothrombin fragment F1 + 2 concentration, a marker of the in vivo rate of generation of thrombin, was 25 (12 to 37)% lower on average while on gemfibrozil than during the placebo phase. Factor VII coagulant activity (VIIc) and antigen concentration, and fibrinopeptide A concentration were not influenced by gemfibrozil in the group overall. However, the VIIc response appeared to be dependent upon the untreated cholesterol level. Hypercholesterolaemic men (cholesterol greater than 6.5 mmol/l) experienced a significant reduction in VIIc averaging 6% of standard during active therapy. Other effects of gemfibrozil were a 5 (2 to 9)% increase in plasma fibrinogen by a gravimetric method, an 11 (8 to 13)% increase in platelet count, and a 6 (2 to 10)% reduction in white cell count. The reduced incidence of CHD following gemfibrozil therapy in hyperlipidaemic patients may arise in part through a reduction in procoagulant activity and thus the risk of an occlusive coronary thrombosis.
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Affiliation(s)
- H C Wilkes
- MRC Epidemiology and Medical Care Unit, Northwick Park Hospital, Harrow, UK
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28
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Millenson MM, Bauer KA, Kistler JP, Barzegar S, Tulin L, Rosenberg RD. Monitoring "mini-intensity" anticoagulation with warfarin: comparison of the prothrombin time using a sensitive thromboplastin with prothrombin fragment F1+2 levels. Blood 1992; 79:2034-8. [PMID: 1562730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Treatment with warfarin using a target International Normalized Ratio (INR) range of 1.7 to 2.5 is efficacious for many clinical indications, but the minimal intensity of anticoagulation required for antithrombotic protection has yet to be determined. To evaluate whether patients could be reliably monitored with a less intense regimen, we anticoagulated patients with warfarin for several months using a target INR range of 1.3 to 1.6 as determined by prothrombin time (PT) using a sensitive thromboplastin (Dade IS, International Sensitivity Index [ISI] = 1.3). Plasma measurements of F1+2, a marker of factor Xa action on prothrombin in vivo, were also obtained to determine the suppressive effect of warfarin on hemostatic system activity. Overall, 20 of 21 patients with a history of cerebrovascular events (mean age, 61 years) could be reliably regulated with warfarin in the target INR range. F1+2 levels were significantly suppressed from baseline in all patients, with a mean reduction of 49% (range, 28% to 78%). We found a significant relationship between the extent of suppression of prothrombin activation levels and the baseline measurements. A mean reduction of 65% was observed for those patients with baseline F1+2 greater than or equal to 1.5 nmol/L, but only 38% for baseline F1+2 less than or equal to 0.5 nmol/L. Overall, 68% of plasma samples obtained during stable anticoagulation were within the target INR range. PTs were also determined on all plasma samples with two thromboplastins of lower sensitivity (C+, ISI = 2.09; and automated simplastin, ISI = 2.10). Only 47% and 35% of PT determinations, respectively, were within the target range with these reagents. We conclude that prothrombin activation can be significantly suppressed in vivo with use of warfarin in an INR range of 1.3 to 1.6. This level of anticoagulation can be reliably achieved by monitoring PTs with a thromboplastin of high sensitivity.
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Affiliation(s)
- M M Millenson
- Department of Medicine, Beth Israel Hospital, Boston, MA 02215
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Bauer KA, Mannucci PM, Gringeri A, Tradati F, Barzegar S, Kass BL, ten Cate H, Kestin AS, Brettler DB, Rosenberg RD. Factor IXa-factor VIIIa-cell surface complex does not contribute to the basal activation of the coagulation mechanism in vivo. Blood 1992; 79:2039-47. [PMID: 1562731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We have infused recombinant factor VIIa into patients with hereditary factor VII deficiency with marked reductions in plasma concentrations of factor IX activation peptide (FIXP), factor X activation peptide (FXP), and prothrombin activation fragment F1+2. These investigations show substantial elevations in these markers of coagulation activation and thereby demonstrate that the factor VII-tissue factor pathway is largely responsible for the activation of factor IX as well as factor X in the basal state (ie, the absence of thrombosis or provocative stimuli). We have administered a monoclonal antibody purified factor IX concentrate to individuals with hemophilia B. These studies show an increase in the plasma levels of FIXP that were initially greatly decreased, but no change in FXP or F1+2. We have also infused highly purified factor VIII concentrate into patients with hemophilia A. The data demonstrate no significant changes in the plasma concentrations of FXP and F1+2. The above observations indicate that factor IXa generated by the factor VII-tissue factor pathway is unable to activate factor X under basal conditions. Based upon the above findings, we outline a model of blood coagulation system function under basal conditions, and suggest a process by which the generation of factor Xa and thrombin might be accelerated during normal hemostasis and in the setting of thrombotic disorders.
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Affiliation(s)
- K A Bauer
- Department of Medicine, Beth Israel Hospital, Boston, MA 02215
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Mannucci PM, Bauer KA, Gringeri A, Barzegar S, Santagostino E, Tradati FC, Rosenberg RD. No activation of the common pathway of the coagulation cascade after a highly purified factor IX concentrate. Br J Haematol 1991; 79:606-11. [PMID: 1772782 DOI: 10.1111/j.1365-2141.1991.tb08088.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Purer factor IX concentrates, containing very little or no factor II or X, have been developed in an attempt to avoid the thromboembolic complications that occur with prothrombin complex concentrates (PCC), which also contain factors II and X and variable amounts of factor VII. To evaluate ex vivo the thrombogenic potential of one of these purer concentrates, we studied whether large single doses produced signs of activation of the coagulation cascade in patients with haemophilia B, and compared the results with those obtained after infusion of a PCC. Seven patients were infused with 50 IU/kg of factor IX concentrate and seven additional patients were subsequently infused with 100 IU/kg of the same concentrate. After the infusions, factor IX levels rose in proportion to the administered dose while the concentrations of factor II and factor X did not rise at all. At both doses of concentrate, we did not observe significant post-infusion increments in the levels of the factor X activation peptide (a measure of the activity of the factor VIIa-tissue factor complex and/or the factor IXa-VIIIa-activated surface complex), prothrombin fragment 1 + 2 (a measure of factor Xa activity), and fibrinopeptide A (a measure of thrombin activity). We also infused 10 patients with a PCC (50 IU/kg). After the infusions, significant rises in the concentrations of the factor X activation peptide and prothrombin fragment were observed. Therefore, it appears that the infusion of a PCC to patients with haemophilia B can augment factor X activation and subsequently thrombin generation in vivo and that this process can be abrogated by the administration of more pure factor IX concentrate.
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Affiliation(s)
- P M Mannucci
- Bianchi Bonomi Hemophilia and Thrombosis Center, University of Milan, Italy
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Abstract
The levels of prothrombin fragment F1 + 2 were measured by a double antibody radioimmunoassay in blood samples collected into different anticoagulant solutions. We evaluated healthy males between the ages of 42 and 77, asymptomatic patients with hereditary deficiencies of protein C or protein S, and persons receiving tumor necrosis factor infusions. The results in specimens collected in an anticoagulant containing ACD, EDTA, adenosine, and 25 U/ml of heparin (a) were highly correlated with those collected in an anticoagulant containing a synthetic thrombin inhibitor, EDTA, and aprotinin (b). However, in asymptomatic patients with congenital antithrombin III deficiency, we found that the plasma levels of F1 + 2 in blood collected in anticoagulant (a) were usually substantially higher than those collected in anticoagulant (b). We determined that this phenomenon was not attributable to the venipuncture procedure itself, but rather appears to be due to the action of low concentrations of heparin in the presence of reduced blood levels of antithrombin III. Our data show that the previously documented elevations in plasma F1 + 2 levels in patients with congenital antithrombin III deficiency appear to be caused by the above in vitro anticoagulant effect, and that this population does not exhibit evidence of a prethrombotic state as defined by the F1 + 2 assay.
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Affiliation(s)
- K A Bauer
- Charles A. Dana Research Institute, Boston, MA
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Mannucci PM, Bauer KA, Gringeri A, Barzegar S, Bottasso B, Simoni L, Rosenberg RD. Thrombin generation is not increased in the blood of hemophilia B patients after the infusion of a purified factor IX concentrate. Blood 1990; 76:2540-5. [PMID: 2265248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Prothrombin complex concentrates (PCC), licensed for the treatment of hemophilia B, are known to carry a significant risk of thromboembolic complications. Although the reasons for thrombogenicity are not completely understood, several manufacturers have developed purified factor IX concentrates that contain negligible amounts of the other vitamin K-dependent factors. To evaluate whether or not the infusion of such a factor IX concentrate is followed by lesser activation of the hemostatic system than by the infusion of a PCC, we performed a series of coagulation assays on 11 hemophilia B patients before and after the administration of these two types of concentrate using a randomized cross-over design. The levels of prothrombin fragment F1 + 2, a sensitive measure of the in vivo cleavage of prothrombin by factor Xa, was significantly increased in plasma after PCC, but not after factor IX concentrate. Plasma fibrinopeptide A, a sensitive index of the enzymatic activity of thrombin on fibrinogen, also increased significantly after PCC but not after factor IX concentrate. The fragment B beta 15-42, a sensitive index of the enzymatic action of plasmin on fibrin II, did not change after either concentrate. There were also no differences in less sensitive coagulation measurements, such as plasma fibrinogen, antithrombin III, and fibrin monomers, nor in indices of platelet activation, such as beta-thromboglobulin and platelet factor 4. These findings show that the infusion of a purified factor IX concentrate can result in substantially less activation of the coagulation cascade than may be seen with PCC.
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Affiliation(s)
- P M Mannucci
- A. Bianchi Bonomi Hemophilia and Thrombosis Center, University of Milan, Italy
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Bauer KA, ten Cate H, Barzegar S, Spriggs DR, Sherman ML, Rosenberg RD. Tumor necrosis factor infusions have a procoagulant effect on the hemostatic mechanism of humans. Blood 1989; 74:165-72. [PMID: 2752108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Several investigators have reported that tumor necrosis factor (TNF) can alter the hemostatic properties of vascular endothelial cells in vitro. We have examined the in vivo effects on the hemostatic mechanism of recombinant human TNF administered as a continuous intravenous infusion to 23 cancer patients with active disease. A battery of sensitive and specific immunochemical techniques were used to monitor changes in blood coagulability. Serial determinations of F1 + 2, the protein C activation peptide (PCP), and fibrinopeptide A (FPA) were obtained prior to the initiation of the TNF infusions and at three and 24 hours after the start of therapy in 12 individuals who received greater than 3 x 10(5) U/m2/24h. The mean levels of F1 + 2, PCP, and FPA were significantly elevated at both time points as compared to the baseline values. The metabolic behavior of 125I-F1 + 2 in an animal model was not affected by infusions of the cytokine. We therefore conclude that the observed elevations in the concentration of this marker in humans receiving TNF result from hemostatic system hyperactivity. In 11 subjects infused with 1 x 10(5) to 2.4 x 10(5) U/m2/24 h of the cytokine, the mean levels of F1 + 2, PCP, and FPA were not significantly greater at 24 hours as compared with the baseline values, indicating that there is a threshold dose at which the cytokine can exert a biochemical effect on the coagulation system. Our studies demonstrate that TNF is able to provide a substantial net procoagulant stimulus to the hemostatic mechanism, and suggest that this cytokine may be a mediator of certain hypercoagulable states in humans.
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Affiliation(s)
- K A Bauer
- Charles A. Dana Research Institute, Beth Israel Hospital, Boston, MA 02215
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Conway EM, Bauer KA, Barzegar S, Rosenberg RD. Suppression of hemostatic system activation by oral anticoagulants in the blood of patients with thrombotic diatheses. J Clin Invest 1987; 80:1535-44. [PMID: 3680513 PMCID: PMC442421 DOI: 10.1172/jci113239] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
RIAs for hemostatic system activation were employed to study patients who were anticoagulated with warfarin. The mean prothrombin fragment F1 + 2 concentration in stably anticoagulated individuals without an inherited thrombotic diathesis (mean prothrombin time [PT] ratio [PT of patient/PT of normal plasma pool] = 1.74) was 0.231 nM as compared with a mean plasma F1 + 2 level of 1.68 nM for a nonanticoagulated control group (P less than 0.0001). The initiation of oral anticoagulants in two subjects who did not exhibit protein C deficiency led to a paradoxical increase in F1 + 2 levels during the first day of therapy. We have also shown that a relatively low intensity regimen of warfarin (PT ratio less than 1.2) may reduce elevated concentrations of F1 + 2 into the normal range in patients with a history of recurrent thromboembolism. The mean F1 + 2 level in antithrombin-deficient individuals on warfarin was significantly elevated (mean = 0.714 nM) as compared with that in anticoagulated subjects with protein C deficiency (mean = 0.205 nM) or in those without an inherited thrombotic disorder (P less than 0.01) at equivalent levels of intensity of oral anticoagulation. We therefore conclude that the effect of warfarin on hemostatic system activation is modulated by the endogenous heparan sulfate-antithrombin mechanism.
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Affiliation(s)
- E M Conway
- Charles A. Dana Research Institute, Boston, Massachusetts
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Dix D, Cohen P, Barzegar S. The incidence of female breast and genital cancer: analysis of the age-dependence. Anticancer Res 1983; 3:251-5. [PMID: 6881922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Worldwide age-incidence patterns for female breast and genital cancers were normalized for differences in frequency of tumor occurrence and compared. The percentage of total cancer incidence which occurred in elderly subjects differed between populations but was similar for cancer of the breast, ovary, and corpus uteri within a given population. In addition, cancers of the breast, ovary, and corpus uteri exhibited similar ranges of distribution about the worldwide median incidence at all age intervals and strong positive correlations between crude incidence rates in the populations studied. Despite these and other similarities, breast cancer exhibited a correlation between crude incidence rate and percentage of total incidence which occurred in elderly subjects which was not apparent in the genital cancers. We cannot exclude the possibility that this correlation is coincidental. However the possibility of identifying factors predisposing to or protecting against breast cancer is attractive. The results of this study suggest that such factors would apply to breast but not to genital tissue.
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Dix D, Cohen P, Barzegar S. Estimating biological variation in diagnostic tests. Clin Chem 1982; 28:1982. [PMID: 7127818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Dix D, Cohen P, Barzegar S, Striefler M. The oral glucose tolerance test: a comparison of the time points on the basis of limit values, normal dispersion, and reproducibility. Acta Diabetol Lat 1981; 18:21-6. [PMID: 7211087 DOI: 10.1007/bf02056102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Time points in the glucose tolerance test (GTT) are compared on the basis of limit values, dispersion within a reference population, and reproducibility. We suggest using the distance between a limit value and the median reference value as a measure of the magnitude of abnormality. The distance between 140 mg/100 ml and the median fasting plasma glucose value is chosen as a standard distance and limits for other points in the GTT are calculated to equal this standard distance of abnormality. We suggest that the probability of correctly interpreting an individual result is directly related to the reproducibility of the test and inversely related to the percentage of the total range of values which is dispersed among the normal population. The ratio of reproducibility to percentage normal dispersion is proposed as an index of the probability of correctly interpreting an individual result. According to this index, and probability of correct interpretation varies in order: fasting plasma glucose concentration greater than 3-h greater than 2-h greater than 0.5-h greater than 1-h plasma glucose concentration.
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