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Sample records for high-normal plasma fibrinogen

  1. Evaluation of a rapid method of determination of plasma fibrinogen.

    PubMed

    Thomson, G W; McSherry, B J; Valli, V E

    1974-07-01

    An evaluation was made of a rapid semiautomated method of determining fibrinogen levels in bovine plasma. This method, the fibrometer method of Morse, Panek and Menga (8), is based on the principle that when thrombin is added to suitably diluted plasma the time of clotting is linearly related to the fibrinogen concentration. A standard curve prepared using bovine plasma had an r value of .9987 and analysis of variance showed there was no significant deviation from regression. A comparison of the fibrometer method and the biuret method of Ware, Guest and Seegers done on 158 bovine plasma samples showed good correlation between the two methods. It was concluded that the fibrometer method does measure bovine fibrinogen and has considerable merit for use in clinical diseases of cattle. PMID:4277474

  2. Prognostic Impact of Pretreatment Plasma Fibrinogen in Patients with Locally Advanced Oral and Oropharyngeal Cancer

    PubMed Central

    Holzinger, Daniel; Danilovic, Ivan; Seemann, Rudolf; Kornek, Gabriela; Engelmann, Johannes; Pillerstorff, Robert; Holawe, Simone; Psyrri, Amanda; Erovic, Boban M.; Farwell, Gregory; Perisanidis, Christos

    2016-01-01

    Background We aimed to determine the prognostic significance of pretreatment plasma fibrinigen in patients with oral and oropharyngeal squamous cell carcinoma (OOSCC). Methods A cohort of 183 patients with locally advanced OOSCC receiving preoperative chemoradiotherapy was retrospectively examined. Using ROC curve analysis, a pretreatment plasma fibrinogen cutoff value of 447mg/dL was determined. The primary endpoints were overall survival and recurrence-free survival. A secondary endpoint was to determine whether pretreatment plasma fibrinogen could predict treatment response to neoadjuvant chemoradiotherapy. Cox regression models and Kaplan–Meier curves were used for survival analyses. Results Seventy-one patients had an elevated pretreatment plasma fibrinogen (fibrinogen >447mg/dL). Patients with high fibrinogen showed significantly higher pathologic stages after neoadjuvant treatment than those with low fibrinogen (p = 0.037). In univariate analysis, elevated fibrinogen was associated with poor overall survival (p = 0.005) and recurrence-free survival (p = 0.008) Multivariate analysis revealed that elevated fibrinogen remained an independent risk factor for death (hazard ratio 1.78, 95% CI 1.09–2.90, p = 0.021) and relapse (hazard ratio 1.78, 95% CI 1.11–2.86, p = 0.016). Conclusion Elevated pretreatment plasma fibrinogen is associated with lack of response to neoadjuvant chemoradiotherapy and reduced OS and RFS in patients with OOSCC. Thus, plasma fibrinogen may emerge as a novel prognostic indicator and a potential therapeutic target in OOSCC. PMID:27362659

  3. Nutritional status influences plasma fibrinogen concentration: evidence from the THUSA survey.

    PubMed

    James, S; Vorster, H H; Venter, C S; Kruger, H S; Nell, T A; Veldman, F J; Ubbink, J B

    2000-06-01

    Nutritional status and risk factors for chronic diseases, including plasma fibrinogen and its determinants, of Africans in the Northwest Province of South Africa, have been studied in a cross-sectional survey. A representative sample of 1854 "apparently healthy" African men and women volunteers aged 15 years and older was recruited from 37 randomly selected sites throughout the Province and stratified for level of urbanisation. Information was collected using validated and culture-sensitive questionnaires. Fasting blood samples were drawn, and all measurements were done with standardised methodology using appropriate equipment, procedures, and controls. Fibrinogen concentration was measured in citrated plasma with the method of Clauss, using the ACL200 automated system and the international fibrinogen standard. The results revealed a population with a high mean plasma fibrinogen (3.17+/-1.10 g/L for HIV-negative men and 3. 64+/-1.12 g/L for HIV-negative women). Factors known to influence plasma fibrinogen, such as age, gender, smoking habit, and physical activity, were also observed in this population. Young rural men and women had the lowest fibrinogen level. Nasal snuff taking and HIV infection did not influence fibrinogen concentration. Multivariate analyses revealed that lower plasma fibrinogen was associated with low to normal body mass index in women, and with dietary intakes compatible with prudent dietary guidelines in men and women (low intakes of animal protein; trans fatty acids and higher intakes of plant protein; dietary fibre, vitamin E, and iron, and a high dietary P/S ratio). Subjects in the higher quartiles of plasma fibrinogen had significantly lower iron, vitamin E, and vitamin B6 (women) status. Increases in fibrinogen were associated with significant increases in serum lipids. Both under- and overnutrition seem to be associated with high plasma fibrinogen. It is concluded that overall nutritional status, possibly in addition to specific

  4. Utility of plasma fibrinogen in the differential diagnosis of thyrotoxicosis

    PubMed Central

    Ma, Jie; Liu, Rui; Wu, Di; Miao, Wei; Chen, Qian; Li, Yushu; Guan, Haixia

    2015-01-01

    Background: A study had reported that a low TSH level is associated with elevated plasma fibrinogen (FIB) levels. Our purpose was to investigate the role of FIB in the differential diagnosis of thyrotoxicosis. Methods: The data of 104 patients with primary thyrotoxicosis at the First Hospital of China Medical University from July 2010 to March 2011 were analyzed and divided into three groups: 45 cases of subacute thyroiditis, 50 cases of Graves’ disease, and 9 cases of toxic multinodular goiter. The patients with subacute thyroiditis were followed up before and after the treatment. FIB levels of the three groups were compared. Results: There was no significant difference in serum TSH, FT3 and FT4 between the patients with three different causes of thyrotoxicosis (P > 0.05). The proportion of hyperfibrinogenemia in patients with subacute thyroiditis was 98%. The FIB levels of patients with subacute thyroiditis were significantly higher than those with Graves’ disease and toxic multinodular goiter (P < 0.05). Levels of ESR show a similar tendency. The FIB levels returned to normal with the remission of subacute thyroiditis. Conclusions: Elevated plasma fibrinogen is a common manifestation of the active phase of subacute thyroiditis. A FIB test can be used for the differential diagnosis of thyrotoxicosis. We can anticipate the outcome of subacute thyroiditis through the dynamic changes of FIB. PMID:25785116

  5. Association between Plasma Fibrinogen Levels and Mortality in Acute-on-Chronic Hepatitis B Liver Failure

    PubMed Central

    Shao, Zhexin; Zhao, Ying; Feng, Limin; Feng, Guofang; Zhang, Juanwen; Zhang, Jie

    2015-01-01

    Acute-on-chronic liver failure (AoCLF) is the most common type of liver failure and is associated with high mortality. Fibrinogen is critical in maintaining primary and secondary hemostasis. Therefore, we prospectively analyzed the association between fibrinogen and outcomes in AoCLF patients. Plasma fibrinogen was measured in 169 AoCLF, 173 chronic hepatitis B (CHB), and 171 healthy patients using a coagulation method. The predictive ability of fibrinogen for 3-month mortality in AoCLF patients was assessed using receiver operating characteristic (ROC) curve and multivariable logistic regression analyses. Plasma fibrinogen was significantly lower in nonsurvivor AoCLF patients compared with survivor AoCLF, CHB, and control patients. The sensitivity, specificity, and area under the ROC curve of 1/fibrinogen predicting mortality in AoCLF patients were 66.7%, 72.5%, and 0.746 (95% confidence interval (CI): 0.672–0.820, P < 0.001), and the fibrinogen cutoff value was 0.90 g/L. On multivariate logistic regression analysis, low fibrinogen was an independent factor predicting mortality (odds ratio: 0.304; 95% CI: 0.094–0.983; P = 0.047). Nonsurvivor AoCLF patients had significantly decreased fibrinogen levels, suggesting that low plasma fibrinogen may be a useful predictor of poor prognosis in AoCLF patients. PMID:25960593

  6. Protein adsorption to polyethylene glycol modified liposomes from fibrinogen solution and from plasma.

    PubMed

    Price, M E; Cornelius, R M; Brash, J L

    2001-06-01

    Unmodified and polyethylene glycol (PEG) modified neutral and negatively charged liposomes were prepared by freeze-thaw and extrusion followed by chromatographic purification. The effects of PEG molecular weight (PEG 550, 2000, 5000), PEG loading (0-15 mol%), and liposome surface charge on fibrinogen adsorption were quantified using radiolabeling techniques. All adsorption isotherms increased monotonically over the concentration range 0-3 mg/ml and adsorption levels were low. Negatively charged liposomes adsorbed significantly more fibrinogen than neutral liposomes. PEG modification had no effect on fibrinogen adsorption to neutral liposomes. An inverse relationship was found between PEG loading of negatively charged liposomes and fibrinogen adsorption. PEGs of all three molecular weights at a loading of 5 mol% reduced fibrinogen adsorption to negatively charged liposomes. Protein adsorption from diluted plasma (10% normal strength) to four different liposome types (neutral, PEG-neutral, negatively charged, and PEG-negatively charged) was investigated using gel electrophoresis and immunoblotting. The profiles of adsorbed proteins were similar on all four liposome types, but distinctly different from the profile of plasma itself, indicating a partitioning effect of the lipid surfaces. alpha2-macroglobulin and fibronectin were significantly enriched on the liposomes whereas albumin, transferrin, and fibrinogen were depleted compared to plasma. Apolipoprotein AI was a major component of the adsorbed protein layers. The blot of complement protein C3 adsorbed on the liposomes suggested that the complement system was activated. PMID:11406096

  7. Adsorption Studies with AFM of Human Plasma Fibrinogen on Silicon Surfaces

    NASA Astrophysics Data System (ADS)

    Gause, Sheena; Kong, Wendy; Rowe

    2007-11-01

    Fibrinogen (FGN) plays an important role in the clotting of blood. Human plasma fibrinogen (HPF) is a protein that readily adsorbs on biomaterial surfaces. The purpose of this experiment was to use the Atomic Force Microscope to study the adsorption of HPF molecules or FGN onto several silicon surfaces with different orientations and resistivities. The size of the FGN molecules found to be somewhat different of Si(111), (100) and (110) were compared to the size of the FGN molecules in solution (45 nm in length, the end dynodes measures to be 6.5 nm in diameter, and the middle dynode measures to be 5 nm in diameter. For this study, the CPR (Thermo-microscope) Atomic Force Microscope (AFM) was used to observe the amount of fibrinogen molecules adsorbed by Si (111) with a resistance of .0281-.0261 φ cm, Si (111) with a resistance of 1 φ cm, Si (100), and Si (110) surfaces. In finding any single fibrinogen molecules, the appropriate image scans and measurements were taken. After collection and analysis of the data, it was found from AFM that the fibrinogen molecules found on Si (110) mostly resembled fibrinogen molecules found in solution. The other images showed that the fibrinogen molecules adsorbed on Silicon substrates is significantly greater (˜10-20 %) than those in solution.

  8. Interactions between segmented polyurethane surfaces and the plasma protein fibrinogen.

    PubMed

    Stupp, S I; Kauffman, J W; Carr, S H

    1977-03-01

    Surfaces of a segmented polyurethane were varied by casting on poly(ethylene terephthalate) (PET) and glass substrates, and were characterized through infrared-attenuated total-reflection spectroscopy (ATR). Surfaces cast on glass substrates showed a higher content of polyether segments, whereas those cast on PET contained a higher relative concentration of aromatic segments. Adsorption, and possible conformational changes of fibrinogen, were found to be more substantial on polymer surfaces having a higher content of polyether segments. It is concluded that the relatively good blood compatibility of segmented polyurethanes is partly due to the presence of peptide-like bonds on aromatic segments. PMID:140169

  9. Clinical and Prognostic Significance of Preoperative Plasma Fibrinogen Levels in Patients with Operable Breast Cancer

    PubMed Central

    Lu, Xiaofei; Liu, Haixia; Li, Xiangyi; Ma, Rong

    2016-01-01

    Purpose Elevated plasma fibrinogen levels are associated with tumor progression and poor outcomes in different cancer patients. The objective of this study was to investigate the clinical and prognostic value of preoperative plasma fibrinogen levels in patients with operable breast cancer. Methods Two hundred and twenty-three patients diagnosed with breast cancer were retrospectively evaluated in this study. Plasma fibrinogen levels were examined before treatment and analyzed along with patient clinicopathological parameters, disease-free survival (DFS) and overall survival(OS). Both univariate and multivariate analyses were performed to identify the clinicopathological parameters associated with DFS and OS. Results Elevated preoperative plasma fibrinogen levels were directly associated with age of diagnose (≤47 vs. >47, p<0.001), menopause (yes vs. no, p<0.001), tumor size (T1&T2 vs.T3&T4, p = 0.033), tumor stage (Ⅰvs.Ⅱvs.Ⅲ, p = 0.034) and lymph node involvement (N = 0 vs. 1≤N≤3 vs. N≥4, p<0.001), but not with histological grade, molecular type and other Immunohistochemical parameters(ER, PR, HER2 and Ki-67). In a univariate survival analysis, tumor stage, tumor size, lymph node involvement (p<0.001/ p<0.001)and plasma fibrinogen (p<0.001/ p<0.001) levels were associated with disease-free and overall survival, but just lymph nodes involvement (p<0.001, hazard ratio [HR] = 2.9, 95% confidence interval [CI] = 1.6–5.3/ p = 0.006, HR = 3.2, 95% CI = 1.4–7.3) and plasma fibrinogen levels (p = 0.006, HR = 3.4, 95% CI = 1.4–8.3/ p = 0.002, HR = 10.1, 95% CI = 2.3–44.6) were associated with disease-free and overall survival in a multivariate survival analysis, respectively. Conclusions This study demonstrates that elevated preoperative plasma fibrinogen levels are associated with breast cancer progression and are independently associated with a poor prognosis in patients with operable breast cancer. PMID:26799214

  10. Evaluation of a rapid method of determination of plasma fibrinogen in swine.

    PubMed

    Fontaine, M; McSherry, B J; Valli, V E

    1977-04-01

    An evaluation was made of a rapid semiautomated method for determining fibrinogen level in swine plasma. This method, referred to as thrombin time method or fibrometer method, is based on the principle that when thrombin is added to suitably diluted plasma, the time of clotting is linearly related to the fibrinogen concentration. The linear regression model for the standard curve prepared using swine plasma had an r value of 0.998. A comparison between the fibrometer and the Grannis methods done on 189 swine plasma samples showed good correlation between these two mehtods (r value 0.847). It was concluded that although the fibrometer method may not be as precise as the Grannis method, it would still be acceptable for clinical use in swine. PMID:861838

  11. Relationship between Physical Activity and Plasma Fibrinogen Concentrations in Adults without Chronic Diseases

    PubMed Central

    Gomez-Marcos, Manuel A.; Recio-Rodríguez, José I.; Patino-Alonso, Maria C.; Martinez-Vizcaino, Vicente; Martin-Borras, Carme; de-la-Cal-dela-Fuente, Aventina; Sauras-Llera, Ines; Sanchez-Perez, Alvaro; Agudo-Conde, Cristina; García-Ortiz, Luis

    2014-01-01

    Objective To analyze the relationship between regular physical activity, as assessed by accelerometer and 7-day physical activity recall (PAR), and plasma fibrinogen concentrations. Methods A cross-sectional study in a previously established cohort of healthy subjects was performed. This study analyzed 1284 subjects who were included in the EVIDENT study (mean age 55.0±13.6 years; 60.90% women). Fibrinogen concentrations were measured in blood plasma. Physical activity was assessed with a 7-day PAR (metabolic equivalents (METs)/hour/week) and GT3X ActiGraph accelerometer (counts/minute) for 7 days. Results Physical exercise, which was evaluated with both an accelerometer (Median: 237.28 counts/minute) and 7-day PAR (Median: 8 METs/hour/week). Physical activity was negatively correlated with plasma fibrinogen concentrations, which was evaluated by counts/min (r = −0.100; p<0.001) and METs/hour/week (r = −0.162; p<0.001). In a multiple linear regression analysis, fibrinogen concentrations of the subjects who performed more physical activity (third tertile of count/minute and METs/hour/week) respect to subjects who performed less (first tertile), maintained statistical significance after adjustments for age and others confounders (β = −0.03; p = 0.046 and β = −0.06; p<0.001, respectively). Conclusions Physical activity, as assessed by accelerometer and 7-day PAR, was negatively associated with plasma fibrinogen concentrations. This relation is maintained in subjects who performed more exercise even after adjusting for age and other confounders. PMID:24498413

  12. Can Plasma Fibrinogen Levels Predict Bleeding After Coronary Artery Bypass Grafting?

    PubMed Central

    Jalali, Alireza; Ghiasi, Mohammadsaeid; Aghaei, Aghdas; Khaleghparast, Shiva; Ghanbari, Behrooz; Bakhshandeh, Hooman

    2014-01-01

    Background: Fibrinogen is the main biomarker for bleeding. To prevent excessive postoperative bleeding, it would be useful to identify high-risk patients before coronary artery bypass grafting (CABG). Objectives: In order to predicating bleeding after CABG, we sought to determine whether preoperative fibrinogen concentration was associated with the amount of bleeding following CABG. Patients and Methods: A total of 144 patients (mean age = 61.50 ± 9.42 years; 65.7% men), undergoing elective and isolated CABG, were included in this case-series study. The same anesthesia technique and medicines were selected for all the patients. In the ICU, the patients were assessed in terms of bleeding at 12 and 24 hours post-operation, amount of contingent blood products received, and relevant tests. Statistical tests were subsequently conducted to analyze the correlation between preoperative fibrinogen concentration and the amount of post-CABG bleeding. Results: The mean ± standard deviation of bleeding at 12 and 24 hours post-operation was 285.37 ± 280.27 and 499.31 ± 355.57 mL, respectively. The results showed that postoperative bleeding was associated with different factors whereas pre-anesthesia fibrinogen was not correlated with bleeding at 12 (P = 0.856) and 24 hours (P = 0.936) post-operation. There were correlations between the extra-corporal circulation time and bleeding at 12 hours post-operation (ρ = 0.231, P = 0.007) and bleeding at 24 hours post-operation (ρ = 0.218, P = 0.013). Conclusions: Preoperative assessment of plasma fibrinogen levels failed to predict post-CABG bleeding. PMID:25478546

  13. Fibrinogen Brescia

    PubMed Central

    Brennan, Stephen O.; Wyatt, Jane; Medicina, Daniela; Callea, Francesco; George, Peter M.

    2000-01-01

    The proposita suffered from liver cirrhosis and biopsy showed type 1 membrane-bound fiberglass inclusions. The hepatic inclusion bodies were weakly periodic acid-Schiff diastase-positive, and on immunoperoxidase staining reacted specifically with anti-fibrinogen antisera. Coagulation investigations revealed low functional and antigenic fibrinogen together with a prolonged thrombin time of 37 seconds (normal, 17 to 22 seconds) suggestive of a hypodysfibrinogenemia. DNA sequencing of all three fibrinogen genes showed a single heterozygous mutation of GGG (Gly)→CGG (Arg) at codon 284 of the γ-chain gene. However, examination of purified fibrinogen chains by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, reverse-phase high-performance liquid chromatography, ion-exchange high-performance liquid chromatography, and isoelectric focusing, failed to show any evidence of the mutant γBr chain in plasma fibrinogen. This finding was substantiated by electrospray ionization mass spectrometry, which showed only a normal γ (and Bβ) chain mass, but a large increase in the portion of their disialo isoforms. We speculate that misfolding of the variant protein causes hepatic retention and the subsequent hypofibrinogenemia, and that the functional defect (dysfibrinogenemia) results from hypersialylation of otherwise normal Bβ and γ chains consequent to the liver cirrhosis. These conclusions were supported by studies on six other family members with hypofibrinogenemia, and essentially normal clotting times, who were heterozygous for the γ284 Gly→Arg mutation. PMID:10880389

  14. Preoperative Plasma Fibrinogen Level Represents an Independent Prognostic Factor in a Chinese Cohort of Patients with Upper Tract Urothelial Carcinoma

    PubMed Central

    Jin, Jie; Zhou, Li-Qun; He, Zhi-Song; Shen, Cheng; He, Qun; Li, Jun; Liu, Li-Bo; Wang, Cong; Chen, Xiao-Yu; Fan, Yu; Hu, Shuai; Zhang, Lei; Yu, Wei; Han, Wen-Ke

    2016-01-01

    Background Increased plasma fibrinogen is thought to contribute to tumor progression and metastasis. The association of plasma fibrinogen with clinicopathological characteristics, and the optimal cutoff with an ideal predictive value has not been fully determined in patients with upper tract urothelial carcinoma (UTUC). We aimed to investigate the clinical significance of this parameter in a Chinese cohort of patients with UTUC. Methods A retrospective study was conducted to analyze the clinical data of 184 operable UTUC patients in a Chinese cohort with a high incidence of chronic kidney disease (CKD). An optimal cutoff was set for further analysis according to validated web-based software. The associations of plasma fibrinogen with clinicopathological characteristics and survival were assessed. Multivariate analyses were performed to determine the independent prognostic factors. Results Elevated plasma fibrinogen was significantly associated with tumor necrosis, lymph node involvement, and a higher preoperative CKD stage, pathological tumor stage and grade (all P < 0.05). Kaplan-Meier analysis showed that plasma fibrinogen ≥ 3.54 g/L predicted a poorer overall and cancer-specific survival than < 3.54 g/L (P < 0.001 for both). Multivariate analyses revealed that elevated preoperative plasma fibrinogen was an independent negative prognostic factor for overall survival (HR = 2.026; 95% CI: 1.226–3.349; P = 0.006) and cancer-specific survival (HR = 1.886; 95% CI: 1.019–3.490; P = 0.043). Conclusions Increased plasma fibrinogen was an independent prognostic risk factor for poor outcomes in UTUC. This parameter may serve as an effective biomarker with easy accessibility for evaluating prognosis for patients with UTUC. PMID:26930207

  15. The plasma protein fibrinogen stabilizes clusters of red blood cells in microcapillary flows

    PubMed Central

    Brust, M.; Aouane, O.; Thiébaud, M.; Flormann, D.; Verdier, C.; Kaestner, L.; Laschke, M. W.; Selmi, H.; Benyoussef, A.; Podgorski, T.; Coupier, G.; Misbah, C.; Wagner, C.

    2014-01-01

    The supply of oxygen and nutrients and the disposal of metabolic waste in the organs depend strongly on how blood, especially red blood cells, flow through the microvascular network. Macromolecular plasma proteins such as fibrinogen cause red blood cells to form large aggregates, called rouleaux, which are usually assumed to be disaggregated in the circulation due to the shear forces present in bulk flow. This leads to the assumption that rouleaux formation is only relevant in the venule network and in arterioles at low shear rates or stasis. Thanks to an excellent agreement between combined experimental and numerical approaches, we show that despite the large shear rates present in microcapillaries, the presence of either fibrinogen or the synthetic polymer dextran leads to an enhanced formation of robust clusters of red blood cells, even at haematocrits as low as 1%. Robust aggregates are shown to exist in microcapillaries even for fibrinogen concentrations within the healthy physiological range. These persistent aggregates should strongly affect cell distribution and blood perfusion in the microvasculature, with putative implications for blood disorders even within apparently asymptomatic subjects. PMID:24614613

  16. The plasma protein fibrinogen stabilizes clusters of red blood cells in microcapillary flows

    NASA Astrophysics Data System (ADS)

    Brust, M.; Aouane, O.; Thiébaud, M.; Flormann, D.; Verdier, C.; Kaestner, L.; Laschke, M. W.; Selmi, H.; Benyoussef, A.; Podgorski, T.; Coupier, G.; Misbah, C.; Wagner, C.

    2014-03-01

    The supply of oxygen and nutrients and the disposal of metabolic waste in the organs depend strongly on how blood, especially red blood cells, flow through the microvascular network. Macromolecular plasma proteins such as fibrinogen cause red blood cells to form large aggregates, called rouleaux, which are usually assumed to be disaggregated in the circulation due to the shear forces present in bulk flow. This leads to the assumption that rouleaux formation is only relevant in the venule network and in arterioles at low shear rates or stasis. Thanks to an excellent agreement between combined experimental and numerical approaches, we show that despite the large shear rates present in microcapillaries, the presence of either fibrinogen or the synthetic polymer dextran leads to an enhanced formation of robust clusters of red blood cells, even at haematocrits as low as 1%. Robust aggregates are shown to exist in microcapillaries even for fibrinogen concentrations within the healthy physiological range. These persistent aggregates should strongly affect cell distribution and blood perfusion in the microvasculature, with putative implications for blood disorders even within apparently asymptomatic subjects.

  17. The plasma protein fibrinogen stabilizes clusters of red blood cells in microcapillary flows.

    PubMed

    Brust, M; Aouane, O; Thiébaud, M; Flormann, D; Verdier, C; Kaestner, L; Laschke, M W; Selmi, H; Benyoussef, A; Podgorski, T; Coupier, G; Misbah, C; Wagner, C

    2014-01-01

    The supply of oxygen and nutrients and the disposal of metabolic waste in the organs depend strongly on how blood, especially red blood cells, flow through the microvascular network. Macromolecular plasma proteins such as fibrinogen cause red blood cells to form large aggregates, called rouleaux, which are usually assumed to be disaggregated in the circulation due to the shear forces present in bulk flow. This leads to the assumption that rouleaux formation is only relevant in the venule network and in arterioles at low shear rates or stasis. Thanks to an excellent agreement between combined experimental and numerical approaches, we show that despite the large shear rates present in microcapillaries, the presence of either fibrinogen or the synthetic polymer dextran leads to an enhanced formation of robust clusters of red blood cells, even at haematocrits as low as 1%. Robust aggregates are shown to exist in microcapillaries even for fibrinogen concentrations within the healthy physiological range. These persistent aggregates should strongly affect cell distribution and blood perfusion in the microvasculature, with putative implications for blood disorders even within apparently asymptomatic subjects. PMID:24614613

  18. Plasma fibrinogen is associated with cognitive decline and risk for dementia in patients with mild cognitive impairment.

    PubMed

    Xu, G; Zhang, H; Zhang, S; Fan, X; Liu, X

    2008-07-01

    This study was aimed to investigate the relationship between plasma fibrinogen level and risk for cognitive decline and dementia in patients with mild cognitive impairment (MCI). Elderly patients with suspected cognitive impairment were screened and evaluated periodically. One hundred and eighty-five patients who met the criteria for MCI were enrolled. Blood coagulation functions and plasma fibrinogen levels were measured at baseline. Hyperfibrinogenaemia was defined as plasma fibrinogen > or =3.0 g/l. Global cognitive function was assessed serially with Mini-Mental State Examination (MMSE). The enrolled patients were followed for 2 years to observe if dementia was developed. There were 185 patients diagnosed as MCI, of which 17 (9.2%) deceased, 15 (8.1%) lost to follow-up, and 68 (36.8%) developed dementia during follow-up. Mean of MMSE score of the enrolled patients declined significantly during follow-up (22.0 +/- 3.0 vs. 18.1 +/- 5.8, p < 0.001). Patients with hyperfibrinogenaemia at baseline had greater MMSE decrement during follow-up than patients with normal fibrinogen level (-5.4 +/- 5.4 vs. -3.5 +/- 4.5, p < 0.05). Linear regression indicated that plasma fibrinogen level was associated with cognitive decline (R = 0.17, p < 0.05). Patients with hyperfibrinogenaemia had an increased risk for dementia and vascular dementia compared with patients with normal level of plasma fibrinogen (log rank test, p < 0.05). There was a trend that hyperfibrinogenaemia also increased risk for dementia of Alzheimer's type (p = 0.061). It can be concluded that plasma fibrinogen level may be associated with cognitive decline, and hyperfibrinogenaemia may increase risk for dementia in patients with MCI. PMID:17916180

  19. Reduced plasma fibrinogen, serum peroxides, lipids, and apolipoproteins after a 3-week vegetarian diet.

    PubMed

    Høstmark, A T; Lystad, E; Vellar, O D; Hovi, K; Berg, J E

    1993-01-01

    The influence of a 3-week vegetarian diet and fasting on serum concentration of peroxides, lipids, apolipoproteins, and plasma fibrinogen was studied in ten middle-aged fibromyalgia/fibrositis patients (eight women, two men). Mean serum peroxide concentration (estimated as thiobarbituric acid reacting substances) was reduced from 3.60 +/- 0.14 to 2.82 +/- 0.15 umol/l (p = 0.01) and plasma fibrinogen from 3.33 +/- 0.25 to 2.74 +/- 0.15 g/l (p = 0.02). Serum total cholesterol fell from 6.61 +/- 0.50 to 4.83 +/- 0.35 mmol/l (p < 0.0001), apolipoprotein B from 1.77 +/- 0.14 to 1.31 +/- 0.11 g/l (p < 0.0001), and apolipoprotein A from 1.41 +/- 0.09 to 1.23 +/- 0.05 g/l (p = 0.03). High density lipoprotein cholesterol concentration also decreased somewhat (from 1.26 +/- 0.09 to 1.07 +/- 0.04 mmol/l, p = 0.03) An atherogenic index, reflecting the balance between low and high density lipoproteins, was reduced by 31% (from 5.74 +/- 0.79 to 3.97 +/- 0.60, p = 0.02). The results suggest that vegetarian diet/fasting may have a beneficial influence on the concentration of serum peroxides and plasma fibrinogen concentration, and on the serum level of several lipoprotein-related coronary risk factors. PMID:8464845

  20. Label-Free Quantitative Immunoassay of Fibrinogen in Alzheimer Disease Patient Plasma Using Fiber Optical Surface Plasmon Resonance

    NASA Astrophysics Data System (ADS)

    Kim, Jisoo; Kim, SeJin; Nguyen, Tan Tai; Lee, Renee; Li, Tiehua; Yun, Changhyun; Ham, Youngeun; An, Seong Soo A.; Ju, Heongkyu

    2016-05-01

    We present a real-time quantitative immunoassay to detect fibrinogen in the blood plasma of Alzheimer's disease patients using multimode fiber optical sensors in which surface plasmon resonance (SPR) was employed. Nanometer-thick bimetals including silver and aluminum were coated onto the core surface of the clad-free part (5 cm long) of the fiber for SPR excitation at the He-Ne laser wavelength of 632.8 nm. The histidine-tagged peptide was then coated on the metal surface to immobilize the fibrinogen antibody for the selective capture of fibrinogen among the proteins in the patient blood plasma. The SPR fiber optical sensor enabled quantitative detection of concentrations of fibrinogen from the different human patient blood at a detection limit of ˜20 ng/ml. We also observed a correlation in the fibrinogen concentration measurement between enzyme-linked immunosorbent assay and our SPR fiber-based sensors. This suggests that the presented SPR fiber-based sensors that do not rely on the use of labels such as fluorophores can be used for a real-time quantitative assay of a specific protein such as fibrinogen in a human blood that is known to contain many other kinds of proteins together.

  1. Interaction of platelets, fibrinogen and endothelial cells with plasma deposited PEO-like films

    NASA Astrophysics Data System (ADS)

    Yang, Zhilu; Wang, Jin; Li, Xin; Tu, Qiufen; Sun, Hong; Huang, Nan

    2012-02-01

    For blood-contacting biomedical implants like retrievable vena cava filters, surface-based diagnostic devices or in vivo sensors, limiting thrombosis and cell adhesion is paramount, due to a decrease even failure in performance. Plasma deposited PEO-like films were investigated as surface modifications. In this work, mixed gas composed of tetraethylene glycol dimethyl ether (tetraglyme) vapor and oxygen was used as precursor. It was revealed that plasma polymerization under high ratio of oxygen/tetraglyme led to deposition of the films that had high content of ether groups. This kind of PEO-like films had good stability in phosphate buffer solution. In vitro hemocompatibility and endothelial cell (EC) adhesion revealed low platelet adhesion, platelet activation, fibrinogen adhesion, EC adhesion and proliferation on such plasma deposited PEO-like films. This made it a potential candidate for the applications in anti-fouling surfaces of blood-contacting biomedical devices.

  2. Nattokinase decreases plasma levels of fibrinogen, factor VII, and factor VIII in human subjects.

    PubMed

    Hsia, Chien-Hsun; Shen, Ming-Ching; Lin, Jen-Shiou; Wen, Yao-Ke; Hwang, Kai-Lin; Cham, Thau-Ming; Yang, Nae-Cherng

    2009-03-01

    Nattokinase, a serine proteinase from Bacillus subtilis, is considered to be one of the most active functional ingredients found in natto. In this study, we hypothesized that nattokinase could reduce certain factors of blood clotting and lipids that are associated with an increase risk for cardiovascular disease (CVD). Thus, an open-label, self-controlled clinical trial was conducted on subjects of the following groups: healthy volunteers (Healthy Group), patients with cardiovascular risk factors (Cardiovascular Group), and patients undergoing dialysis (Dialysis Group). All subjects ingested 2 capsules of nattokinase (2000 fibrinolysis units per capsule) daily orally for 2 months. The laboratory measurements were performed on the screening visit and, subsequently, regularly after the initiation of the study. The intent-to-treat analysis was performed on all 45 enrolled subjects. By use of mixed model analysis, a significant time effect, but not group effect, was observed in the change from baseline of fibrinogen (P = .003), factor VII (P < .001), and factor VIII (P < .001), suggesting that the plasma levels of the 3 coagulation factors continuously declined during intake; also, the extents of decrease were similar between groups. After 2 months of administration, fibrinogen, factor VII, and factor VIII decreased 9%, 14%, and 17%, respectively, for the Healthy Group; 7%, 13%, and 19%, respectively, for the Cardiovascular Group; and 10%, 7%, and 19%, respectively, for the Dialysis Group, whereas blood lipids were unaffected by nattokinase. No significant changes of uric acid or notable adverse events were observed in any of the subjects. In summary, this study showed that oral administration of nattokinase could be considered as a CVD nutraceutical by decreasing plasma levels of fibrinogen, factor VII, and factor VIII. PMID:19358933

  3. The significance of fibrinogen derivatives in plasma in human renal failure.

    PubMed

    Lane, D A; Ireland, H; Knight, I; Wolff, S; Kyle, P; Curtis, J R

    1984-02-01

    The concentrations in plasma of fibrinogen derivatives fibrinopeptide A (FPA), beta 15-42 antigen and fragment E (FgE) antigen have been determined in patients with renal failure and compared to the concentrations of the platelet release products, beta-thromboglobulin (beta TG) and platelet factor 4 (PF4). In 'partial renal failure' (51Cr-EDTA clearance rate 4-60 ml/min) FPA, beta 15-42 antigen, FgE antigen and beta TG levels were significantly raised above a normal laboratory control group. These levels were further raised in a group of patients whose disease required regular maintenance haemodialysis (51Cr-EDTA clearance rate less than 4 ml/min). PF4 levels were not significantly raised in either group. A statistical analysis of all patient results revealed that FPA, beta 15-42 antigen and FgE antigen levels all correlated with beta TG levels but not with PF4 levels. It is known that beta TG is catabolized by the kidney but PF4 is not and that elevated beta TG levels in renal failure are caused by impaired elimination rather than increased production. These results suggest that the plasma levels of these three fibrinogen derivatives are elevated in renal disease at least in part by decreased elimination rather than by increased thrombin and plasmin activities alone. PMID:6229269

  4. Estimation of plasma fibrinogen degradation products in oral submucous fibrosis: A clinico-pathological study

    PubMed Central

    Reshma, V. J; Anwar, A Shihab; Mufeed, Abdulla; Roshni, A

    2015-01-01

    Background: Oral submucous fibrosis (OSF) is a disease of the oral mucosa characterized by excessive accumulation of subepithelial collagen, thereby resulting in severe limitation of mouth opening. In OSF, in response to inflammation, the body produces more fibrinogen and its degradation products. The plasma fibrinogen degradation products (FDP) have been reported to be early indicators of fibrin deposition. The present study was intended to ascertain the role of FDP in OSF. Materials and Methods: A total of 40 subjects were included in the study. The subjects for the present study were selected from the Department of Oral Medicine and Radiology. The subjects were divided into two groups. The study group comprised 24 subjects diagnosed clinically and histopathologically as OSF and were further divided into three clinical and histological stages of OSF. The control group comprised 16 age- and gender-matched healthy individuals. Five milliliters of venous blood was drawn from the antecubital fossa of all the participants. The blood samples were centrifuged at 1000 rpm for 5 min to separate plasma, and the plasma FDP levels were assessed. Results and Conclusion: There was a significant difference in the plasma FDP levels between the study group and the control group. There was a significant linear increase of plasma FDP levels with an increase in severity of the clinical stage of OSF. Comparison with the histopathological grades of OSF also showed an increase in FDP levels with higher grades of OSF and there was a good correlation between the clinical staging and the histopathological grading of OSF. PMID:26312231

  5. Fibrinogen and ceruloplasmin in plasma and milk from dairy cows with subclinical and clinical mastitis.

    PubMed

    Tabrizi, A Davasaz; Batavani, R A; Rezaei, S Asri; Ahmadi, M

    2008-02-15

    The potential using of Acute Phase Proteins (APPs) in the assessment of mammary gland health was studied by examining the levels of Fibrinogen (Fb) and Ceruloplasmin (Cp) in plasma and milk from dairy cows with different grades of mastitis. Plasma samples were taken from jugular vein and milk samples were collected from quarters of cows with subclinical and clinical mastitis, as well as healthy controls. California Mastitis Test (CMT) were performed on each udder quarter of cows for detection of CMT2+ and CMT3+ quarters. CMT (0) and culture negative cases were considered healthy cows. Clinical mastitis, was graded as mild (clots in milk) or moderate (clots in milk and visible signs of inflammation in the mammary gland/s). The concentrations of Fb in the plasma of the cows with subclinical and clinical mastitis were higher than in the plasma of the healthy cows (p<0.01). There was no significant difference in plasma concentration of Cp between healthy and subclinical groups (p>0.05), but differences between clinical and healthy groups were significant (p<0.05). The concentrations of Fb and Cp in the milk of the cows with subclinical and clinical mastitis were higher than in the milk of the healthy cows (p<0.01). The results indicated that measurement of Fb in plasma and milk and Cp only in milk might be suitable for early diagnosis of mastitis in dairy cows. PMID:18817128

  6. Fibrinogen gene regulation.

    PubMed

    Fish, Richard J; Neerman-Arbez, Marguerite

    2012-09-01

    The Aα, Bβ and γ polypeptide chains of fibrinogen are encoded by a three gene cluster on human chromosome four. The fibrinogen genes (FGB-FGA-FGG) are expressed almost exclusively in hepatocytes where their output is coordinated to ensure a sufficient mRNA pool for each chain and maintain an abundant plasma fibrinogen protein level. Fibrinogen gene expression is controlled by the activity of proximal promoters which contain binding sites for hepatocyte transcription factors, including proteins which influence fibrinogen transcription in response to acute-phase inflammatory stimuli. The fibrinogen gene cluster also contains cis regulatory elements; enhancer sequences with liver activities identified by sequence conservation and functional genomics. While the transcriptional control of this gene cluster is fascinating biology, the medical impetus to understand fibrinogen gene regulation stems from the association of cardiovascular disease risk with high level circulating fibrinogen. In the general population this level varies from about 1.5 to 3.5 g/l. This variation between individuals is influenced by genotype, suggesting there are genetic variants contributing to fibrinogen levels which reside in fibrinogen regulatory loci. A complete picture of how fibrinogen genes are regulated will therefore point towards novel sources of regulatory variants. In this review we discuss regulation of the fibrinogen genes from proximal promoters and enhancers, the influence of acute-phase stimulation, post-transcriptional regulation by miRNAs and functional regulatory variants identified in genetic studies. Finally, we discuss the fibrinogen locus in light of recent advances in understanding chromosomal architecture and suggest future directions for researching the mechanisms that control fibrinogen expression. PMID:22836683

  7. Plasma Fibrinogen Is a Natural Deterrent to Amyloid β–Induced Platelet Activation and Neuronal Toxicity

    PubMed Central

    Sonkar, Vijay K; Kulkarni, Paresh P; Chaurasia, Susheel N; Dash, Ayusman; Jauhari, Abhishek; Parmar, Devendra; Yadav, Sanjay; Dash, Debabrata

    2016-01-01

    Alzheimer’s disease (AD) is a devastating neurodegenerative disorder, characterized by extensive loss of neurons and deposition of amyloid β (Aβ) in the form of extracellular plaques. Aβ is considered to have a critical role in synaptic loss and neuronal death underlying cognitive decline. Platelets contribute to 95% of circulating amyloid precursor protein that releases Aβ into circulation. We have recently demonstrated that the Aβ active fragment containing amino acid sequence 25–35 (Aβ25–35) is highly thrombogenic in nature and elicits strong aggregation of washed human platelets in a RhoA-dependent manner. In this study, we evaluated the influence of fibrinogen on Aβ-induced platelet activation. Intriguingly, Aβ failed to induce aggregation of platelets suspended in plasma but not in buffer. Fibrinogen brought about dose-dependent decline in aggregatory response of washed human platelets elicited by Aβ25–35, which could be reversed by increasing doses of Aβ. Fibrinogen also attenuated Aβ-induced platelet responses such as secretion, clot retraction, rise in cytosolic Ca+2 and reactive oxygen species. Fibrinogen prevented intracellular accumulation of full-length Aβ peptide (Aβ42) in platelets as well as neuronal cells. We conclude that fibrinogen serves as a physiological check against the adverse effects of Aβ by preventing its interaction with cells. PMID:27262026

  8. Influence of fibrinogen degradation products on thrombin time, activated partial thromboplastin time and prothrombin time of canine plasma.

    PubMed

    Mischke, R; Wolling, H

    2000-01-01

    To investigate how thrombin time, activated partial thromboplastin time (APTT) and prothrombin time are influenced by fibrinogen degradation products (FDP), different concentrations (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8 and 1.0 mg/ml) of the purified FDP X, Y, D and E were added to the plasma of healthy dogs. If fragment Y was added to the plasma a considerable inhibitory effect could be demonstrated for all three test systems. A significant prolongation (p < 0.05) was found for concentrations of > or =0.1 mg/ml (thrombin time, APTT) and > or =0.2 mg/ml (prothrombin time). With FDP Y concentrations from >0.185 mg/ml (prothrombin time) to >0.24 mg/ml (APTT) coagulation time was prolonged beyond the respective reference range. As regards the other fragments, a comparable inhibitory effect could only be shown for fragment X added to the thrombin time test system. This effect can most probably be explained by the competition of the FDP X and fibrinogen for the fibrinogen binding sites of thrombin, rather than by a fibrin polymerization disorder. The results demonstrate that for plasma with normal fibrinogen concentration the group tests are only prolonged beyond the reference range at FDP concentrations very rarely found in spontaneous hyperfibrinolysis. PMID:11014962

  9. Associations of plasma fibrinogen levels with established cardiovascular disease risk factors, inflammatory markers, and other characteristics: individual participant meta-analysis of 154,211 adults in 31 prospective studies: the fibrinogen studies collaboration.

    PubMed

    Kaptoge, S; White, I R; Thompson, S G; Wood, A M; Lewington, S; Lowe, G D O; Danesh, J

    2007-10-15

    Long-term increases in plasma fibrinogen levels of 1 g/liter are associated with an approximate doubling of risk of major cardiovascular disease outcomes, but causality remains uncertain. To quantify cross-sectional associations of fibrinogen levels with established risk factors and other characteristics, the investigators combined individual data on 154,211 apparently healthy adults from 31 prospective studies conducted between 1967 and 2003, using a linear mixed model that included random effects at the cohort level. Fibrinogen levels increased with age and showed continuous, approximately linear relations with several risk markers and slightly curvilinear associations with log triglycerides, albumin, and tobacco and alcohol consumption. Female sex, Black ethnicity, lower socioeconomic status, and alcohol abstinence were each associated with modestly higher fibrinogen levels. Approximately one third of the variation in fibrinogen levels was explained by cohort, age, and sex. An additional 7% was explained by established risk factors (notably, positive associations with smoking and body mass index and an inverse association with high density lipoprotein cholesterol), and a further 10% was explained by inflammatory markers (notably, a positive association with C-reactive protein). The association with body mass index was twice as strong in women as in men, whereas the association with smoking was much stronger in men. These findings substantially advance understanding of the correlates and possible determinants of fibrinogen levels. PMID:17785713

  10. The effects of genotype and infant weight on adult plasma levels of fibrinogen, factor VII, and LDL cholesterol are additive.

    PubMed Central

    Henry, J A; Bolla, M; Osmond, C; Fall, C; Barker, D J; Humphries, S E

    1997-01-01

    High circulating levels of cholesterol, particularly low density lipoprotein (LDL) cholesterol and the clotting factors fibrinogen and factor VII, are associated with increased risk of myocardial infarction. Variations in the plasma levels of these factors are determined in part by polymorphisms in the genes concerned and also by weight at 1 year (infant weight). We have looked at the possibility of interactions between these genetic factors and infant weight in a sample of 290 men and 192 women from Hertfordshire using the beta-fibrinogen G/A-455, factor VII R353Q, and ApoE polymorphisms. The rare allele frequencies of the three polymorphisms were 0.19 for beta-fibrinogen, 0.10 for factor VII, and 0.07 and 0.13 for the 2 and 4 alleles of ApoE, and these frequencies were not different in subjects of different infant weight. In this sample, the polymorphisms showed the expected effects on plasma levels of fibrinogen, factor VII, and LDL cholesterol. The A-455 allele was associated with higher fibrinogen levels but the effect was only statistically significant in women (p = 0.003). The R353 allele was associated with higher factor VII activity in both men and women (p < 0.0001 for both). The ApoE2 allele was associated with lower levels of LDL cholesterol (p = 0.03 in men, p = 0.006 in women), while the ApoE4 allele was associated with higher levels (p < 0.001 in men, not significant in women). In this sample of men and women the effect of low infant weight was only associated with significant effects on fibrinogen and LDL cholesterol in the group of men (p = 0.005 and p = 0.008 respectively). Compared with the E3E3 subjects, the LDL lowering effect of the E2 allele and the raising effect of the E4 allele was greater in those with low infant weight compared with those with high infant weight (low v high infant weight for E2: 12.7% v 9.4%; for E4 12.7% v 8.5%). Although in this sample the interactive effect did not reach statistical significance, the additive effect

  11. Relation between admission plasma fibrinogen levels and mortality in Chinese patients with coronary artery disease

    PubMed Central

    Peng, Yong; Wang, Hua; Li, Yi-ming; Huang, Bao-tao; Huang, Fang-yang; Xia, Tian-li; Chai, Hua; Wang, Peng-ju; Liu, Wei; Zhang, Chen; Chen, Mao; Huang, De-jia

    2016-01-01

    Fibrinogen (Fib) was considered to be a potential risk factor for the prognosis of patients with coronary artery disease (CAD), but there was lack of the evidence from Chinese contemporary population. 3020 consecutive patients with CAD confirmed by coronary angiography were enrolled and were grouped into 2 categories by the optimal Fib cut-off value (3.17 g/L) for all-cause mortality prediction. The end points were all-cause mortality and cardiac mortality. Cumulative survival curves showed that the risk of all-cause mortality was significantly higher in patients with Fib ≥3.17 g/L compared to those with Fib <3.17 g/L (mortality rate, 11.5% vs. 5.7%, p < 0.001); and cardiovascular mortality obtained results similar to those mentioned above (cardiac mortality rate, 5.9% vs. 3.6%, p = 0.002). Subgroup analysis showed that elevated Fib levels were predictive for the risk of all-cause mortality in the subgroups according to age, medical history, and diagnosis. COX multivariate regression analysis showed that plasma Fib levels remained independently associated with all-cause mortality after adjustment for multiple cardiovascular risk factors (all-cause mortality, HR 2.01, CI 1.51–2.68, p < 0.001). This study has found that Fib levels were independently associated with the mortality risk in Chinese CAD patients. PMID:27456064

  12. Comparison of different methods to measure fibrinogen concentration in canine plasma with respect to their sensitivity towards the fibrinogen degradation products X, Y and D.

    PubMed

    Mischke, R; Menzel, D; Wolling, H

    2000-01-01

    In this study, fibrinogen measurements according to the Clauss method, photometric method and Jacobsson method have been investigated to find out how they are influenced by adding in vitro the purified canine fibrinogen degradation products (FDP) X, Y and D. Test results according to the Clauss method were found to be underestimated if the fragments X, Y and D were added while measurements according to the Jacobsson method turned out to underestimate the real fibrinogen concentration if the FDP Y and D were added. The Clauss method was particularly sensitive towards FDP. Results were considerably underestimated even with a quantity as little as 0.05 g FDP Y or FDP D/g fibrinogen (p < 0.05). The photometric method was only affected by FDP X leading to false high results. If FDP X was added, fibrinogen values were also overestimated with the Jacobsson method. Our results demonstrate that the photometric method is the most accurate. PMID:11014963

  13. Evaluation of Plasma Fibrinogen Degradation Products and Total Serum Protein Concentration in Oral Submucous Fibrosis

    PubMed Central

    B.N.V.S., Satish; B., Maharudrappa; K.M., Prashant; Hugar, Deepa; Allad, Umesh; Prabhu, Prasanth S.

    2014-01-01

    Background: Oral submucous fibrosis (OSMF) is a potentially malignant disorder with a multifactorial etiology. Malnutrition is a major problem for the inhabitants of most countries where OSMF is prevalent. Recently, a new direction in the etiopathogenesis was provided by the identification of fibrinogen degradation products (FDP) in the plasma of OSMF patients. Aims and Objectives: To assess the role of FDP in the etiology of OSMF and to correlate with the nutritional status by evaluating the total serum protein level. The study also determines to evaluate the correlation between the levels of plasma FDP with respect to the staging and grading of OSMF. Correlation between the levels of Total Serum Protein (TSP) with respect to the staging and grading of OSMF was also evaluated. Materials and Methods: The study included 30 cases clinically and histopathologically diagnosed as oral submucous fibrosis. The FDP levels were assessed using both qualitative and semi quantitative method as supplied by ‘Tulip Diagnostics (P) Ltd. Total Serum Protein (TSP) estimation was done by Biuret method using Liquixx Protein kit by Erba, Manheim. Results: The study indicates that in qualitative assessment of FDP only 14 subjects showed the presence of FDP levels>200ng/ml. In semiquantitative assessment there is no significant association between varying clinical stages and histopathological grades and FDP levels. Total serum Protein level showed a marginal increase in all subjects. The study revealed a positive correlation between FDP and TSP in all OSMF subjects. Conclusion: A larger sample size which would be a better representation of the population and the use of different methods which have higher sensitivities and specificities to evaluate FDP level and detailed fractional analysis of protein along with immunoglobulin profiling would facilitate in attaining more conclusive results. PMID:24995245

  14. Removal Dynamics of Immunoglobulin and Fibrinogen by Conventional Plasma Exchange, Selective Plasma Exchange, and a Combination of the Two.

    PubMed

    Miyamoto, Satoko; Ohkubo, Atsushi; Seshima, Hiroshi; Maeda, Takuma; Itagaki, Ayako; Kurashima, Naoki; Iimori, Soichiro; Naito, Shotaro; Sohara, Eisei; Rai, Tatemitsu; Uchida, Shinichi; Okado, Tomokazu

    2016-08-01

    While plasma exchange (PE) can eliminate plasma proteins, including all immunoglobulin (Ig) and coagulation factors, selective plasma exchange (SePE) can retain fibrinogen (Fbg). Here, we investigated the removal dynamics of Ig and Fbg in 53 patients with immunological disorders by PE, SePE, and a combination of the two. When the mean processed plasma volume (PPV) was 0.9 plasma volume (PV), the mean percent reductions of Ig and Fbg by PE were both approximately 62%-65%. When the mean PPV was 1.1 PV, the mean percent reductions by SePE were 53.1% for IgG, 30.1% for IgA, 3.6% for IgM, and 19.0% for Fbg, respectively. In the three plasmapheresis sessions performed on alternate days, we classified treatments into three categories: PE group (PE-PE-PE, N = 2), SePE group (SePE-SePE-SePE, N = 14), and PE/SePE group (PE-SePE-SePE, N = 4). The mean percent reductions of IgG, IgA, IgM, and Fbg were 82.0%, 80.4%, 87.3%, and 80.9%, respectively, for the PE group; 76.4%, 57.7%, 43.3%, and 35.9%, respectively, for the PE/SePE group; and 75.4%, 50.6%, 3.2%, and 29.3%, respectively, for the SePE group. Plasmapheresis modalities can be combined according to clinical conditions, for instance, to achieve both the unspecific removal of pathogens by PE and retention of coagulation factors, such as Fbg, by SePE. PMID:27523073

  15. Plasma Fibrinogen in Type 2 Diabetic Patients with Metabolic Syndrome and its Relation with Ischemic Heart Disease (IHD) and Retinopathy

    PubMed Central

    Mahendra, J.V.; Anuradha, T.S.; Talikoti, Prashanth; Nagaraj, R.S.; Vishali, V.

    2015-01-01

    Introduction: Metabolic syndrome or Syndrome X is characterized by hyperlipidemia, increased blood pressure, abdominal obesity and hyperglycemia, which increases the risk of cardiovascular complications. In addition to these, it is also associated with nontraditional risk factor like C- reactive protein, Plasminogen activator and fibrinogen. Various studies have documented association of these nontraditional risk factor, in Type 2 diabetes mellitus. Thus patients with diabetes mellitus are higher risk of developing micro and macro vascular complications like ischemic heart disease (IHD) and diabetic retinopathy. Diabetic retinopathy is the leading cause of decreased visual acuity, which is associated with maculopathy and profierative complications of it. Chronic hyperglycemia and its associated nonenzymatic glycation play an important role in the development of microangiopathy. Aims and Objectives: To study the prevalence of the metabolic syndrome in type 2 diabetes mellitus. To study the plasma fibrinogen and its relationship with IHD and retinopathy in type 2 Diabetes mellitus patients with metabolic syndrome. Materials and Methods: Patients of type 2 diabetes Mellitus were recruited based on the inclusion and exclusion criteria. History of IHD and ECG evidence of ischemia was obtained. Retinopathy was diagnosed by direct opthalmoscopy. Fasting glucose, lipid profile and plasma fibrinogen were analyzed. Stastical analysis was carried by Chi square test and student‘t’ test. Results: The prevalence of metabolic syndrome in study population of 100 type 2 diabetic patients is 58% and is significantly associated with duration of the disease (p<0.001). Fifty eight patients have hyperfibrinogenemia and mean fibrinogen level is significantly high in diabetic patients with metabolic syndrome when compared to diabetic patients without metabolic syndrome (p<0.001). Diabetic patient with metabolic syndrome and hyperfibrinogenemia have higher prevalence of IHD and

  16. Plasma Fibrinogen as a Biomarker for Mortality and Hospitalized Exacerbations in People with COPD

    PubMed Central

    Mannino, David M; Tal-Singer, Ruth; Lomas, David A.; Vestbo, Jorgen; Graham Barr, R.; Tetzlaff, Kay; Lowings, Michael; Rennard, Stephen I.; Snyder, Jeffrey; Goldman, Mitchell; Martin, Ubaldo J.; Merrill, Deborah; Martin, Amber L.; Simeone, Jason C.; Fahrbach, Kyle; Murphy, Brian; Leidy, Nancy; Miller, Bruce

    2014-01-01

    Background In 2010 the COPD Foundation established the COPD Biomarkers Qualification Consortium (CBQC) as a partnership between the Foundation, the Food and Drug Administration (FDA), and the pharmaceutical industry to pool publicly-funded and industry data to develop innovative tools to facilitate the development and approval of new therapies for COPD. We present data from the initial project seeking regulatory qualification of fibrinogen as a biomarker for the stratification of COPD patients into clinical trials. Methods This analysis pooled data from 4 publicly-funded studies and 1 industry study into a common database resulting in 6376 individuals with spirometric evidence of COPD. We used a threshold of 350 mg/dL to determine high vs. low fibrinogen, and determined the subsequent risk of hospitalizations from exacerbations and death using Cox proportional hazards models. Results High fibrinogen levels at baseline were present in 2853 (44.7%) of individuals with COPD. High fibrinogen was associated with an increased risk of hospitalized COPD exacerbations within 12 months (hazard ratio [HR]: 1.64; 95% confidence interval [CI]: 1.39–1.93) among participants in the Atherosclerosis Risk in Communities Study (ARIC), the Cardiovascular Health Study (CHS), and the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study. High fibrinogen was associated with an increased risk of death within 36 months (HR: 1.94; 95% CI: 1.62–2.31) among all participants. Conclusions Fibrinogen levels ≥ 350 mg/dL identify COPD individuals at an increased risk of exacerbations and death and could be a useful biomarker for enriching clinical trials in the COPD population. PMID:25685850

  17. Risk of Future Diabetes in Japanese People with High-normal Fasting Plasma Glucose Levels: A 4-Year Follow-up Study.

    PubMed

    Watanabe, Yoh; Eto, Tanenao; Taniguchi, Shotaro; Terauchi, Yasuo

    2016-01-01

    Objective There is no definite consensus regarding the treatment and guidance for individuals with high-normal fasting plasma glucose levels (FPG;100-109 mg/dL). The present study aimed to determine the risk factors for future diabetes in Japanese people with high-normal FPG. Methods Retrospective cohort studies were conducted from 2008 to 2012, including 15,097 individuals who underwent medical examinations. First, the participants were divided into normal FPG (n=13,065) and high-normal FPG (n=2,032) groups to compare the diabetes incidence. Second, the high FPG group was divided into diabetes onset (n=133) and non-diabetes onset (n=1,899) groups to compare the baseline values. Third, to determine the risk factors for future diabetes in the high-normal FPG group, multivariate analyses were conducted. Results The cumulative incidence during the mean follow-up of 4 years was 94/13,065 (0.72%) and 133/2,032 (6.55%) in the normal FPG and high-normal FPG groups, respectively. Within the high-normal FPG group, the baseline body mass index, waist circumference, triglycerides, FPG, alanine aminotransferase (ALT), and gamma-glutamyl transferase were significantly higher and high-density lipoprotein cholesterol (HDL-C) was significantly lower in the diabetes onset group than in the non-diabetes onset group. Obesity, abdominal obesity, hypertriglyceridemia, low HDL-C, and high ALT were significant risk factors for diabetes according to a multivariate analysis. Conclusion The high-normal FPG group had a higher risk of diabetes than the normal FPG group, particularly when accompanied with obesity, abdominal obesity, hypertriglyceridemia, low HDL-C, and high ALT. Thus, this high risk group should receive appropriate guidance for lifestyle changes to avoid developing diabetes at an early stage. PMID:27580535

  18. Randomised clinical trial of an intensive intervention in the primary care setting of patients with high plasma fibrinogen in the primary prevention of cardiovascular disease

    PubMed Central

    2012-01-01

    Background We have studied the possible effects of an intensive lifestyle change program on plasma fibrinogen levels, in patients with no cardiovascular disease, with elevated levels of fibrinogen, normal cholesterol levels, and a moderate estimated risk of coronary heart disease (CHD) and we have also analysed whether the effect on fibrinogen is independent of the effect on lipids. Results This clinical trial was controlled, unblinded and randomized, with parallel groups, done in 13 Basic Health Areas (BHA) in l'Hospitalet de Llobregat (Barcelona) and Barcelona city. The study included 436 patients, aged between 35 and 75 years, with no cardiovascular disease, elevated levels of fibrinogen (> 300 mg/dl), cholesterol < 250 mg/dl, 218 of whom received a more intensive intervention consisting of advice on lifestyle and treatment. The follow-up frequency of the intervention group was every 2 months. The other 218 patients followed their standard care in the BHAs. Fibrinogen, plasma cholesterol and other clinical biochemistry parameters were assessed. The evaluation of the baseline characteristics of the patients showed that both groups were homogenous. Obesity and hypertension were the most prevalent risk factors. After 24 months of the study, statistically significant changes were seen between the adjusted means of the two groups, for the following parameters: fibrinogen, plasma cholesterol, systolic and diastolic blood pressure and body mass index. Conclusion Intensive intervention to achieve lifestyle changes has shown to be effective in reducing some of the estimated CHD factors. However, the effect of intensive intervention on plasma fibrinogen levels did not correlate with the variations in cholesterol. Trial Registration ClinicalTrials.gov: NCT01089530 PMID:22381072

  19. Influence of heparin on fibrinogen and D-dimer plasma levels in acute myocardial infarction treated with streptokinase.

    PubMed

    Salvioni, A; Marenzi, G C; Agostoni, P; Grazi, S; Guazzi, M D

    1994-05-01

    The purpose of this study was to investigate whether, to what extent, and through which mechanisms intravenous heparin, administered before and after streptokinase, affects the plasma levels of D-dimer and fibrinogen in myocardial infarction. Data concerning mortality and incidence of coronary recanalization in patients receiving heparin and thrombolytic therapy after acute myocardial infarction are controversial; furthermore, the mechanisms through which heparin acts in combination with thrombolytic therapy are unclear. Thirty-eight patients with acute myocardial infarction treated with streptokinase were considered. Nineteen of them received, immediately before the beginning of thrombolytic treatment, a bolus of heparin (100 U.kg-1 intravenously) and, 2 h later, intravenous heparin in doses raising the partial thromboplastin time to 2-2.5 times the normal value (Group 1); the remaining 19 did not receive anticoagulant treatment (Group 2). Multiple determinations of plasma D-dimer and fibrinogen levels were obtained in all patients before, and in the seven days following thrombolytic treatment. Six hours after streptokinase, fibrinogen decreased from 304 +/- 34 to 61 +/- 34 mg.dl-1 in Group 1 and from 312 +/- 29 to 38 +/- 21 mg.dl-1 in Group 2 (P < 0.02 versus Group 1). The same difference between groups persisted at the 12th and at the 18th hour. D-dimer values, from 0.5 +/- 0.1 microgram.dl-1 in Group 1 and 0.4 +/- 0.1 microgram.dl-1 in Group 2, increased at the 1st hour to 37.2 +/- 36.5 micrograms.dl-1 and 52.2 +/- 39.8 micrograms.dl-1, respectively. A peak value was reached in both groups at the 6th hour, which was followed by a slow decrease.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8056006

  20. Determining the effect of storage conditions on prothrombin time, activated partial thromboplastin time and fibrinogen concentration in rat plasma samples.

    PubMed

    Goyal, Vinod Kumar; Kakade, Somesh; Pandey, Santosh Kumar; Gothi, Anil Kalidas; Nirogi, Ramakrishna

    2015-10-01

    Coagulation parameters are usually included in clinical and preclinical safety studies to evaluate the effect of xenobiotics on the extrinsic or intrinsic pathways of coagulation. The analysis is generally performed at the time of terminal sacrifice where many activities are scheduled. Chances of delay in analysis are likely particularly when blood is collected for coagulation via the abdominal vena cava. This experiment was planned to assess the variations in coagulation parameters caused by delay in analysis as well as by storage conditions. Blood was collected from the posterior vena cava under isoflurane anesthesia, and the plasma was separated immediately. Coagulation parameters were evaluated at 0, 6, 24 and 48 h from the plasma stored at room temperature, as well as plasma stored under refrigerated and freezing conditions. Stability of the analytes in blood was also evaluated under refrigerated conditions for 6 h. All parameters were analyzed using a semi-automated coagulometer. Prothrombin time (PT) was stable under all three storage conditions for up to 6 h. Although statistically significant differences were observed for activated partial thromboplastin time (APTT) at room and refrigeration temperatures for up to 6 h, the difference was clinically non-relevant. Fibrinogen was found to be the most stable parameter that showed consistency in results even up to 48 h under all three storage conditions. Plasma for PT can be stored and analyzed without any significant changes for up to 6 h from the actual blood collection, while fibrinogen level testing can be extended for up to 48 h after collection under any storage condition. For reliable APTT results, plasma samples should be run immediately after collection. PMID:26206586

  1. Variations in C-reactive protein, plasma free radicals and fibrinogen values in patients with osteoarthritis treated with Pycnogenol.

    PubMed

    Belcaro, G; Cesarone, M R; Errichi, S; Zulli, C; Errichi, B M; Vinciguerra, G; Ledda, A; Di Renzo, A; Stuard, S; Dugall, M; Pellegrini, L; Gizzi, G; Ippolito, E; Ricci, A; Cacchio, M; Cipollone, G; Ruffini, I; Fano, F; Hosoi, M; Rohdewald, P

    2008-01-01

    In a previous, double-blind, placebo-controlled study we evaluated the efficacy of a 3-month treatment with Pycnogenol for 156 patients with osteoarthritis of the knee. Pycnogenol significantly decreased joint pain and improved joint function as evaluated using the WOMAC score and walking performance of patients on a treadmill. In this study, we further investigated the anti-inflammatory and antioxidant activity of Pycnogenol in a subset of the osteoarthritis patients presenting with elevated C-reactive protein (CRP) and plasma-free radicals. Elevated CRP levels have been suggested to be associated with disease progression in osteoarthritis. In our study, 29 subjects of the Pycnogenol group and 26 patients in the placebo group showed CRP levels higher than 3 mg/l at baseline. Comparison of blood specimens drawn at baseline and after 3-month treatment showed that Pycnogenol significantly decreased plasma free radicals to 70.1% of baseline values. Plasma CRP levels decreased from baseline 3.9 mg/l to 1.1 mg/l in the Pycnogenol group whereas the control group had initial values of 3.9 mg/l which decreased to 3.6 mg/l. The CRP decrease in the Pycnogenol was statistical significant as compared to the control group (P < 0.05). Fibrinogen levels were found to be lowered to 62.8% of initial values (P < 0.05) in response to Pycnogenol. No significant changes for plasma free radicals, CRP and fibrinogen were found in the placebo-treated group. The decrease of systemic inflammatory markers suggests that Pycnogenol may exert anti-inflammatory activity in osteoarthritic joints and patients did not present with other ailments or infections. The nature of the anti-inflammatory effects of Pycnogenol with regard to CRP warrants further investigation. PMID:19017467

  2. Rare and low-frequency variants and their association with plasma levels of fibrinogen, FVII, FVIII, and vWF.

    PubMed

    Huffman, Jennifer E; de Vries, Paul S; Morrison, Alanna C; Sabater-Lleal, Maria; Kacprowski, Tim; Auer, Paul L; Brody, Jennifer A; Chasman, Daniel I; Chen, Ming-Huei; Guo, Xiuqing; Lin, Li-An; Marioni, Riccardo E; Müller-Nurasyid, Martina; Yanek, Lisa R; Pankratz, Nathan; Grove, Megan L; de Maat, Moniek P M; Cushman, Mary; Wiggins, Kerri L; Qi, Lihong; Sennblad, Bengt; Harris, Sarah E; Polasek, Ozren; Riess, Helene; Rivadeneira, Fernando; Rose, Lynda M; Goel, Anuj; Taylor, Kent D; Teumer, Alexander; Uitterlinden, André G; Vaidya, Dhananjay; Yao, Jie; Tang, Weihong; Levy, Daniel; Waldenberger, Melanie; Becker, Diane M; Folsom, Aaron R; Giulianini, Franco; Greinacher, Andreas; Hofman, Albert; Huang, Chiang-Ching; Kooperberg, Charles; Silveira, Angela; Starr, John M; Strauch, Konstantin; Strawbridge, Rona J; Wright, Alan F; McKnight, Barbara; Franco, Oscar H; Zakai, Neil; Mathias, Rasika A; Psaty, Bruce M; Ridker, Paul M; Tofler, Geoffrey H; Völker, Uwe; Watkins, Hugh; Fornage, Myriam; Hamsten, Anders; Deary, Ian J; Boerwinkle, Eric; Koenig, Wolfgang; Rotter, Jerome I; Hayward, Caroline; Dehghan, Abbas; Reiner, Alex P; O'Donnell, Christopher J; Smith, Nicholas L

    2015-09-10

    Fibrinogen, coagulation factor VII (FVII), and factor VIII (FVIII) and its carrier von Willebrand factor (vWF) play key roles in hemostasis. Previously identified common variants explain only a small fraction of the trait heritabilities, and additional variations may be explained by associations with rarer variants with larger effects. The aim of this study was to identify low-frequency (minor allele frequency [MAF] ≥0.01 and <0.05) and rare (MAF <0.01) variants that influence plasma concentrations of these 4 hemostatic factors by meta-analyzing exome chip data from up to 76,000 participants of 4 ancestries. We identified 12 novel associations of low-frequency (n = 2) and rare (n = 10) variants across the fibrinogen, FVII, FVIII, and vWF traits that were independent of previously identified associations. Novel loci were found within previously reported genes and had effect sizes much larger than and independent of previously identified common variants. In addition, associations at KCNT1, HID1, and KATNB1 identified new candidate genes related to hemostasis for follow-up replication and functional genomic analysis. Newly identified low-frequency and rare-variant associations accounted for modest amounts of trait variance and therefore are unlikely to increase predicted trait heritability but provide new information for understanding individual variation in hemostasis pathways. PMID:26105150

  3. Rare and low-frequency variants and their association with plasma levels of fibrinogen, FVII, FVIII, and vWF

    PubMed Central

    Huffman, Jennifer E.; de Vries, Paul S.; Morrison, Alanna C.; Sabater-Lleal, Maria; Kacprowski, Tim; Auer, Paul L.; Brody, Jennifer A.; Chasman, Daniel I.; Chen, Ming-Huei; Guo, Xiuqing; Lin, Li-An; Marioni, Riccardo E.; Müller-Nurasyid, Martina; Yanek, Lisa R.; Pankratz, Nathan; Grove, Megan L.; de Maat, Moniek P. M.; Cushman, Mary; Wiggins, Kerri L.; Qi, Lihong; Sennblad, Bengt; Harris, Sarah E.; Polasek, Ozren; Riess, Helene; Rivadeneira, Fernando; Rose, Lynda M.; Goel, Anuj; Taylor, Kent D.; Teumer, Alexander; Uitterlinden, André G.; Vaidya, Dhananjay; Yao, Jie; Tang, Weihong; Levy, Daniel; Waldenberger, Melanie; Becker, Diane M.; Folsom, Aaron R.; Giulianini, Franco; Greinacher, Andreas; Hofman, Albert; Huang, Chiang-Ching; Kooperberg, Charles; Silveira, Angela; Starr, John M.; Strauch, Konstantin; Strawbridge, Rona J.; Wright, Alan F.; McKnight, Barbara; Franco, Oscar H.; Zakai, Neil; Mathias, Rasika A.; Psaty, Bruce M.; Ridker, Paul M.; Tofler, Geoffrey H.; Völker, Uwe; Watkins, Hugh; Fornage, Myriam; Hamsten, Anders; Deary, Ian J.; Boerwinkle, Eric; Koenig, Wolfgang; Rotter, Jerome I.; Hayward, Caroline; Dehghan, Abbas; Reiner, Alex P.; O’Donnell, Christopher J.

    2015-01-01

    Fibrinogen, coagulation factor VII (FVII), and factor VIII (FVIII) and its carrier von Willebrand factor (vWF) play key roles in hemostasis. Previously identified common variants explain only a small fraction of the trait heritabilities, and additional variations may be explained by associations with rarer variants with larger effects. The aim of this study was to identify low-frequency (minor allele frequency [MAF] ≥0.01 and <0.05) and rare (MAF <0.01) variants that influence plasma concentrations of these 4 hemostatic factors by meta-analyzing exome chip data from up to 76 000 participants of 4 ancestries. We identified 12 novel associations of low-frequency (n = 2) and rare (n = 10) variants across the fibrinogen, FVII, FVIII, and vWF traits that were independent of previously identified associations. Novel loci were found within previously reported genes and had effect sizes much larger than and independent of previously identified common variants. In addition, associations at KCNT1, HID1, and KATNB1 identified new candidate genes related to hemostasis for follow-up replication and functional genomic analysis. Newly identified low-frequency and rare-variant associations accounted for modest amounts of trait variance and therefore are unlikely to increase predicted trait heritability but provide new information for understanding individual variation in hemostasis pathways. PMID:26105150

  4. High normalized beta plasmas exceeding the ideal stability limit and projected RWM active stabilization performance using newly installed feedback sensors in KSTAR

    NASA Astrophysics Data System (ADS)

    Park, Y. S.; Sabbagh, S. A.; Berkery, J. W.; Bialek, J. M.; Yoon, S. W.; Jeon, Y. M.; Bak, J. G.; Ko, W. H.; Hahn, S. H.; Bae, C.; Bae, Y. S.; in, Y. K.; Kim, J.; Lee, S. G.; Kwak, J. G.; Oh, Y. K.; Park, H. K.; Choi, M. J.; Yun, G. S.

    2015-11-01

    H-mode plasma operation of KSTAR has been expanded to significantly surpass the ideal MHD no-wall beta limit by achieving normalized beta up to 4.3 while reducing plasma internal inductance to near 0.7 exceeding the computed n = 1 ideal no-wall limit by a factor of 1.6. These high normalized beta values have been achieved in discharges having BT in the range 0.9-1.1 T after the plasma reached flattop current of 0.35-0.4 MA, with the highest neutral beam heating power of 4 MW. A significant conclusion of the analysis of these plasmas is that low- n global kink/ballooning or RWMs were not detected, and therefore were not the cause of the plasma termination. Advances from the 2015 run campaign aiming to achieve prolonged pulse duration at maximum normalized beta and to subsequently investigate the MHD stability of these plasmas will be reported. As KSTAR H-mode operation can now routinely surpass the ideal no-wall stability limit, n = 1 RWM active control is planned for the device. RWM active feedback using a newly installed set of poloidal magnetic field sensors mounted on the passive stabilizer plates and designed for optimal performance is analyzed using the VALEN-3D code. The advantages of the new sensors over other device sensors for RWM active control are discussed. Supported by U.S. DOE grant DE-FG02-99ER54524.

  5. No Evidence for Genome-Wide Interactions on Plasma Fibrinogen by Smoking, Alcohol Consumption and Body Mass Index: Results from Meta-Analyses of 80,607 Subjects

    PubMed Central

    Chu, Audrey Y.; Trompet, Stella; Lopez, Lorna M.; Fornage, Myriam; Teumer, Alexander; Tang, Weihong; Rudnicka, Alicja R.; Mälarstig, Anders; Hottenga, Jouke-Jan; Kavousi, Maryam; Lahti, Jari; Tanaka, Toshiko; Hayward, Caroline; Huffman, Jennifer E.; Morange, Pierre-Emmanuel; Rose, Lynda M.; Basu, Saonli; Rumley, Ann; Stott, David J.; Buckley, Brendan M.; de Craen, Anton J. M.; Sanna, Serena; Masala, Marco; Biffar, Reiner; Homuth, Georg; Silveira, Angela; Sennblad, Bengt; Goel, Anuj; Watkins, Hugh; Müller-Nurasyid, Martina; Rückerl, Regina; Taylor, Kent; Chen, Ming-Huei; de Geus, Eco J. C.; Hofman, Albert; Witteman, Jacqueline C. M.; de Maat, Moniek P. M.; Palotie, Aarno; Davies, Gail; Siscovick, David S.; Kolcic, Ivana; Wild, Sarah H.; Song, Jaejoon; McArdle, Wendy L.; Ford, Ian; Sattar, Naveed; Schlessinger, David; Grotevendt, Anne; Franzosi, Maria Grazia; Illig, Thomas; Waldenberger, Melanie; Lumley, Thomas; Tofler, Geoffrey H.; Willemsen, Gonneke; Uitterlinden, André G.; Rivadeneira, Fernando; Räikkönen, Katri; Chasman, Daniel I.; Folsom, Aaron R.; Lowe, Gordon D.; Westendorp, Rudi G. J.; Slagboom, P. Eline; Cucca, Francesco; Wallaschofski, Henri; Strawbridge, Rona J.; Seedorf, Udo; Koenig, Wolfgang; Bis, Joshua C.; Mukamal, Kenneth J.; van Dongen, Jenny; Widen, Elisabeth; Franco, Oscar H.; Starr, John M.; Liu, Kiang; Ferrucci, Luigi; Polasek, Ozren; Wilson, James F.; Oudot-Mellakh, Tiphaine; Campbell, Harry; Navarro, Pau; Bandinelli, Stefania; Eriksson, Johan; Boomsma, Dorret I.; Dehghan, Abbas; Clarke, Robert; Hamsten, Anders; Boerwinkle, Eric; Jukema, J. Wouter; Naitza, Silvia; Ridker, Paul M.; Völzke, Henry; Deary, Ian J.; Reiner, Alexander P.; Trégouët, David-Alexandre; O'Donnell, Christopher J.; Strachan, David P.; Peters, Annette; Smith, Nicholas L.

    2014-01-01

    Plasma fibrinogen is an acute phase protein playing an important role in the blood coagulation cascade having strong associations with smoking, alcohol consumption and body mass index (BMI). Genome-wide association studies (GWAS) have identified a variety of gene regions associated with elevated plasma fibrinogen concentrations. However, little is yet known about how associations between environmental factors and fibrinogen might be modified by genetic variation. Therefore, we conducted large-scale meta-analyses of genome-wide interaction studies to identify possible interactions of genetic variants and smoking status, alcohol consumption or BMI on fibrinogen concentration. The present study included 80,607 subjects of European ancestry from 22 studies. Genome-wide interaction analyses were performed separately in each study for about 2.6 million single nucleotide polymorphisms (SNPs) across the 22 autosomal chromosomes. For each SNP and risk factor, we performed a linear regression under an additive genetic model including an interaction term between SNP and risk factor. Interaction estimates were meta-analysed using a fixed-effects model. No genome-wide significant interaction with smoking status, alcohol consumption or BMI was observed in the meta-analyses. The most suggestive interaction was found for smoking and rs10519203, located in the LOC123688 region on chromosome 15, with a p value of 6.2×10−8. This large genome-wide interaction study including 80,607 participants found no strong evidence of interaction between genetic variants and smoking status, alcohol consumption or BMI on fibrinogen concentrations. Further studies are needed to yield deeper insight in the interplay between environmental factors and gene variants on the regulation of fibrinogen concentrations. PMID:25551457

  6. Haem-assisted dityrosine-cross-linking of fibrinogen under non-thermal plasma exposure: one important mechanism of facilitated blood coagulation.

    PubMed

    Ke, Zhigang; Huang, Qing

    2016-01-01

    Although blood coagulation facilitated by non-thermal plasma has been reported several years ago, the insight to the involved mechanisms is still rather limited. In this work, we report our discovery of a new mechanism for the haem-promoted blood-coagulation caused by non-thermal plasma treatment. The reason for the haem role is due to that its oxidized form, namely, hematin, can promote the dityrosine cross-linking of fibrinogen, the most important coagulation protein, to form a membrane-like layer on the surface of the treated blood with plasma exposure. Both haem and non-thermal-plasma generated hydrogen peroxide are requisite for the cross-linking process. We confirmed that fibrinogen can coordinate with the haem iron to form a protein-haem complex which shows pseudo-peroxidase activity, and in the presence of hydrogen peroxide, the complex can induce the dityrosine formation between fibrinogen molecules, leading to the fibrin network necessary for the blood coagulation. Understanding of such an underlying mechanism can be useful to guide more efficient application of non-thermal plasma in the management of hemostasis, thrombosis and etc. PMID:27229173

  7. Haem-assisted dityrosine-cross-linking of fibrinogen under non-thermal plasma exposure: one important mechanism of facilitated blood coagulation

    PubMed Central

    Ke, Zhigang; Huang, Qing

    2016-01-01

    Although blood coagulation facilitated by non-thermal plasma has been reported several years ago, the insight to the involved mechanisms is still rather limited. In this work, we report our discovery of a new mechanism for the haem-promoted blood-coagulation caused by non-thermal plasma treatment. The reason for the haem role is due to that its oxidized form, namely, hematin, can promote the dityrosine cross-linking of fibrinogen, the most important coagulation protein, to form a membrane-like layer on the surface of the treated blood with plasma exposure. Both haem and non-thermal-plasma generated hydrogen peroxide are requisite for the cross-linking process. We confirmed that fibrinogen can coordinate with the haem iron to form a protein-haem complex which shows pseudo-peroxidase activity, and in the presence of hydrogen peroxide, the complex can induce the dityrosine formation between fibrinogen molecules, leading to the fibrin network necessary for the blood coagulation. Understanding of such an underlying mechanism can be useful to guide more efficient application of non-thermal plasma in the management of hemostasis, thrombosis and etc. PMID:27229173

  8. The recombinant LIC10508 is a plasma fibronectin, plasminogen, fibrinogen and C4BP-binding protein of Leptospira interrogans.

    PubMed

    Siqueira, Gabriela H; Teixeira, Aline F; Fernandes, Luis G; de Souza, Gisele O; Kirchgatter, Karin; Romero, Eliete C; Vasconcellos, Silvio A; Vieira, Monica L; Nascimento, Ana Lucia T O

    2016-03-01

    Leptospirosis is a zoonosis caused by pathogenic Leptospira spp. In this study, we report that the recombinant proteins LIC10507, LIC10508 and LIC10509 are recognized by confirmed leptospirosis serum samples at both phases of the disease. The recombinant rLIC10508 and rLIC10507 are plasminogen (PLG)-binding proteins, capable of generating plasmin in the presence of a PLG activator. The proteins bind to PLG in a dose-dependent and saturable manner, fulfilling host-ligand interaction. Furthermore, rLIC10508 interacts with fibrinogen (Fg), plasma fibronectin and C4b binding protein (C4BP). The binding of rLIC10508 to Fg decreases the fibrin clotting in a thrombin-catalyzed reaction. The incubation with 4 μM of protein promoted 40% inhibition upon clotting formation. C4BP bound to rLIC10508 retained its cofactor activity for factor I promoting the cleavage of C4b protein, which may reduce the membrane attack complex formation. Although these proteins have high amino acid sequence similarity, rLIC10508 is the most talented of the three, a behavior that might be explained by its unique putative 3D structure, whereas structures of rLIC10507 and rLIC10509 are very similar. Plasmin generation (rLIC10507 and rLIC10508), together with decreasing fibrin clot formation (rLIC10508) and impairment of the complement system (rLIC10508) may help the bacteria to overcome host defense, facilitating the infection process. PMID:26657108

  9. Plasma Fibrinogen Qualification as a Drug Development Tool in Chronic Obstructive Pulmonary Disease. Perspective of the Chronic Obstructive Pulmonary Disease Biomarker Qualification Consortium.

    PubMed

    Miller, Bruce E; Tal-Singer, Ruth; Rennard, Stephen I; Furtwaengler, Armin; Leidy, Nancy; Lowings, Michael; Martin, Ubaldo J; Martin, Thomas R; Merrill, Debora D; Snyder, Jeffrey; Walsh, John; Mannino, David M

    2016-03-15

    The COPD Foundation Biomarker Qualification Consortium (CBQC) is a unique public-private partnership established in 2010 between the COPD Foundation, the pharmaceutical industry, and academic chronic obstructive pulmonary disease (COPD) experts with advisors from the U.S. NHLBI and the Food and Drug Administration (FDA). This was a direct response to the 2009 publication of a guidance on qualification of drug development tools by the FDA. Although data were believed to be available from publicly funded and industry-funded studies that could support qualification of several tools, the necessary data resided in disparate databases. The initial intent of the CBQC was to integrate these data and submit a dossier for the qualification. This led to the FDA qualification of plasma fibrinogen as a prognostic or enrichment biomarker for all-cause mortality and COPD exacerbations in July 2015. It is the first biomarker drug development tool qualified for use in COPD under the FDA's drug development tool qualification program. This perspective summarizes the FDA's qualification process, the formation of the CBQC, and the effort that led to a successful outcome for plasma fibrinogen and discusses implications for future biomarker qualification efforts. PMID:26745765

  10. Fibrinogen reduction and coagulation in cardiac surgery: an investigational study.

    PubMed

    Gielen, Chantal L I; Grimbergen, Jos; Klautz, Robert J M; Koopman, Jaap; Quax, Paul H A

    2015-09-01

    Fibrinogen as precursor of fibrin plays an essential role in clot formation. There are three main mechanisms associated with a reduction in fibrinogen concentration during cardiac surgery: hemodilution, consumption, and degradation. Moreover, early fibrinogen degradation products (FgDPs) can interfere with normal fibrin formation of intact fibrinogen. The aim of this study was to determine the relative contributions of hemodilution, consumption, and degradation to fibrinogen loss in cardiac surgery and to evaluate the effects fibrinogen degradation products on blood clot formation in vitro. First, fibrin and fibrinogen concentrations, their degradation products, hematocrit, and albumin concentrations were compared in 10 patients before and after isolated coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass. Second, ex-vivo fibrinogen supplementation experiments were performed. Finally, the effects of purified FgDPs on clotting time and clot firmness were established in vitro in whole blood by ROTEM. Fibrinogen plasma concentration decreased 30% during surgery. This drop appears to be mainly caused by hemodilution, as both hematocrit and albumin levels decreased and no relevant increase in D-dimer levels and FgDPs was observed. Furthermore, the coagulation profile normalized after addition of purified fibrinogen. Early FgDPs demonstrated a significant impact on in-vitro whole blood clotting. Although early FgDPs have a pronounced effect on blood clot formation in vitro and therefore may induce or enhance in vivo coagulopathy, the drop of fibrinogen concentration seen after CABG surgery (using tranexamic acid) is primarily caused by hemodilution. PMID:26083991

  11. Antiadhesive effect of fibrinogen: a safeguard for thrombus stability

    PubMed Central

    Lishko, Valeryi K.; Burke, Timothy; Ugarova, Tatiana

    2007-01-01

    The recruitment of phagocytic leukocytes to sites of vessel wall injury plays an important role in thrombus dissolution by proteases elaborated on their adhesion. However, leukocyte adhesion to the fibrin clot can be detrimental at the early stages of wound healing when hemostatic plug integrity is critical for preventing blood loss. Adhesion of circulating leukocytes to the insoluble fibrin(ogen) matrix is mediated by integrins and occurs in the presence of a high concentration of plasma fibrinogen. In this study, the possibility that soluble fibrinogen could protect fibrin from excessive adhesion of leukocytes was examined. Fibrinogen was a potent inhibitor of adhesion of U937 monocytoid cells and neutrophils to fibrin gel and immobilized fibrin(ogen). An investigation of the mechanism by which soluble fibrinogen exerts its influence on leukocyte adhesion indicated that it did not block integrins but rather associated with the fibrin(ogen) substrate. Consequently, leukocytes that engage fibrinogen molecules loosely bound to the surface of fibrin(ogen) matrix are not able to consolidate their grip on the substrate; subsequently, cells detach. This conclusion is based on the evidence obtained in adhesion studies using various cells and performed under static and flow conditions. These findings reveal a new role of fibrinogen in integrin-mediated leukocyte adhesion and suggest that this mechanism may protect the thrombus from premature dissolution. PMID:16849640

  12. Association Between γ′ Fibrinogen Levels and Inflammation

    PubMed Central

    Alexander, Kristine S.; Madden, Theresa E.; Farrell, David H.

    2014-01-01

    Summary The γ′ fibrinogen isoform produces clots that are stiffer and more resistant to breakdown than the more common fibrinogen isoform, γA. Increased levels of γ′ fibrinogen are associated with several forms of cardiovascular disease. The purpose of this cross-sectional study is to investigate the relationship between γ′ fibrinogen, an emerging risk factor for cardiovascular disease, and inflammatory markers in subjects with a chronic inflammatory state. The 284 subjects for this study came from the Periodontitis and Vascular Events study, and γ′ fibrinogen and total fibrinogen in plasma were measured by ELISA. Information on patient demographics and health status, as well as levels of C-reactive protein, an inflammatory marker, have previously been collected for this study. The mean (SE) γ′ fibrinogen level in the subjects was 0.622 (0.017) mg/ml. Levels of γ′ fibrinogen were correlated with C-reactive protein (p = 0.006), with a one unit increase in C-reactive protein associated with a 1.9% increase in γ′ fibrinogen, after adjustment for potential confounders. Total fibrinogen was not correlated with γ′ fibrinogen in these subjects. The number of dental sites with evidence of tissue inflammation was also significantly associated with γ′ fibrinogen levels. These results provide an important step in the evolution of γ′ fibrinogen not only as a general risk factor for cardiovascular disease, but as a potentially useful biomarker for assessing a patient's inflammatory state and associated cardiovascular disease risk. PMID:21174007

  13. Iron modulates the alpha chain of fibrinogen.

    PubMed

    Nielsen, Vance G; Jacobsen, Wayne K

    2016-04-01

    Iron-bound fibrinogen has been noted to accelerate plasmatic coagulation in patients with divergent conditions involving upregulation of heme oxygenase activity, including hemodialysis, Alzheimer's disease, sickle cell anemia, and chronic migraine. Our goal was to determine if a site of iron-fibrinogen interaction was on the alpha chain. Using thrombelastography, we compared the coagulation kinetic profiles of plasma exposed to 0-10 µM ferric chloride after activation of coagulation with thrombin generated by contact activation of plasma with the plastic sample cup or by exposure to 1 µg/ml of Calloselasma rhodostoma venom (rich in ancrod activity), which causes coagulation via polymerization of alpha chain monomers. Venom mediated coagulation always occurred before thrombin activated thrombus formation, and ferric chloride always diminished the time of onset of coagulation and increased the velocity of clot growth. Iron enhances plasmatic coagulation kinetics by modulating the alpha chain of fibrinogen. PMID:26782808

  14. Conformational changes of fibrinogen in dispersed carbon nanotubes

    PubMed Central

    Park, Sung Jean; Khang, Dongwoo

    2012-01-01

    The conformational changes of plasma protein structures in response to carbon nanotubes are critical for determining the nanotoxicity and blood coagulation effects of carbon nanotubes. In this study, we identified that the functional intensity of carboxyl groups on carbon nanotubes, which correspond to the water dispersity or hydrophilicity of carbon nanotubes, can induce conformational changes in the fibrinogen domains. Also, elevation of carbon nanotube density can alter the secondary structures (ie, helices and beta sheets) of fibrinogen. Furthermore, fibrinogen that had been in contact with the nanoparticle material demonstrated a different pattern of heat denaturation compared with free fibrinogen as a result of a variation in hydrophilicity and concentration of carbon nanotubes. Considering the importance of interactions between carbon nanotubes and plasma proteins in the drug delivery system, this study elucidated the correlation between nanoscale physiochemical material properties of carbon nanotubes and associated structural changes in fibrinogen. PMID:22915854

  15. Variations on Fibrinogen-Erythrocyte Interactions during Cell Aging

    PubMed Central

    Carvalho, Filomena A.; de Oliveira, Sofia; Freitas, Teresa; Gonçalves, Sónia; Santos, Nuno C.

    2011-01-01

    Erythrocyte hyperaggregation, a cardiovascular risk factor, is considered to be caused by an increase in plasma adhesion proteins, particularly fibrinogen. We have recently reported a specific binding between fibrinogen and an erythrocyte integrin receptor with a β3 or β3-like subunit. In this study we evaluate the influence of erythrocyte aging on the fibrinogen binding. By atomic force microscopy-based force spectroscopy measurements we found that increasing erythrocyte age, there is a decrease of the binding to fibrinogen by decreasing the frequency of its occurrence but not its force. This observation is reinforced by zeta-potential and fluorescence spectroscopy measurements. We conclude that upon erythrocyte aging the number of fibrinogen molecules bound to each cell decreases significantly, due to the progressive impairment of the specific fibrinogen-erythrocyte receptor interaction. Knowing that younger erythrocytes bind more to fibrinogen, we could presume that this population is the main contributor to the cardiovascular diseases associated with increased fibrinogen content in blood, which could disturb the blood flow. Our data also show that the sialic acids exposed on the erythrocyte membrane contribute for the interaction with fibrinogen, possibly by facilitating its binding to the erythrocyte membrane receptor. PMID:21464904

  16. Indications and Risks of Fibrinogen in Surgery and Trauma.

    PubMed

    Spahn, Donat R; Spahn, Gabriela H; Stein, Philipp

    2016-03-01

    Fibrinogen has a central role in coagulation. Following trauma and perioperatively, low fibrinogen levels have been found to be risk factors for exaggerated bleeding, transfusion needs, and adverse outcome. Conversely, treatment with exogenous fibrinogen in critically bleeding patients with low fibrinogen levels has been shown to decrease transfusion needs. Because following trauma and in many perioperative situations fibrinogen is the first coagulation "element" to become critically low, it appears reasonable to target fibrinogen in clinical coagulation algorithms aiming at early specific and goal-directed treatment. A low fibrinogen can be a low plasma concentration or a low functional fibrinogen as assessed by point-of-care techniques such as thromboelastography (TEG) or thromboelastometry (ROTEM). This review summarizes the evidence base for perioperative algorithm-based fibrinogen administration, including the exact thresholds for fibrinogen administration used in the different algorithms. Algorithm-based individualized goal-directed use of fibrinogen resulted in highly significant reduction in transfusion needs, adverse outcomes, in certain studies even mortality, and where investigated reduced costs, with high safety levels at the same time. Best evidence exists in cardiac surgery, followed by trauma, postpartum hemorrhage, and liver transplantation. The introduction of these concepts is highly demanding and requires a tremendous educational effort to familiarize all health care workers with the necessary knowledge and the skills of how to run TEG/ROTEM tests. Future research is needed to compare the efficacy, safety, and costs of different algorithms. This, however, should not prevent us from introducing these expedient point-of-care-based algorithms clinically today. PMID:26716503

  17. Structural analysis of fibrinogen synthesized by cultured chicken hepatocytes in the presence or absence of dexamethasone.

    PubMed

    Amrani, D L; Plant, P W; Pindyck, J; Mosesson, M W; Grieninger, G

    1983-03-30

    Hepatocyte monolayers, derived from chick embryos and cultured in chemically defined medium without hormones, synthesize and secrete fibrinogen that resembles chicken plasma fibrinogen immunochemically and structurally. Addition of a synthetic glucocorticoid, dexamethasone, to the cultured cells resulted in an appreciable and relatively selective increase in fibrinogen synthesis. Autoradiography of fibrinogen that had been metabolically labelled with [35S]methionine and then subjected to SDS-polyacrylamide gel electrophoresis, unreduced or under disulfide-reducing conditions, revealed that only dimeric forms of fibrinogen, containing undegraded A alpha, B beta, and gamma chains, were secreted under stimulated and unstimulated culture conditions. PMID:6830818

  18. Functional evaluation of an inherited abnormal fibrinogen: fibrinogen “Baltimore”

    PubMed Central

    Beck, Eugene A.; Shainoff, John R.; Vogel, Alfred; Jackson, Dudley P.

    1971-01-01

    The rate of clotting and the rate of development and degree of turbidity after addition of thrombin to plasma or purified fibrinogen from a patient with fibrinogen Baltimore was delayed when compared with normal, especially in the presence of low concentrations of thrombin. Optimal coagulation and development of translucent, rather than opaque, clots occurred at a lower pH with the abnormal fibrinogen than with normal. Development of turbidity during clotting of the abnormal plasma or fibrinogen was less than normal at each pH tested, but was maximal in both at approximately pH 6.4. The physical quality of clots formed from fibrinogen Baltimore was abnormal, as demonstrated by a decreased amplitude on thromboelastography. The morphologic appearance of fibrin strands formed from fibrinogen Baltimore by thrombin at pH 7.4 was abnormal when examined by phase contrast or electron microscopy, but those formed by thrombin at pH 6.4 or by thrombin and calcium chloride were similar to, though less compact, than normal fibrin. The periodicity of fibrin formed from fibrinogen Baltimore was similar to normal and was 231-233 Å. A study of the release of the fibrinopeptides from the patient's fibrinogen and its chromatographic subfractions verified the existence of both a normally behaving and a defective form of fibrinogen in the patient's plasma. The defective form differed from normal in three functionally different ways: (a) the rate of release of fibrinopeptides A and AP was slower than normal; (b) no visible clot formation accompanied either partial or complete release of the fibrinopeptides from the defective form in 0.3 M NaCl at pH 7.4; and (c) the defective component possessed a high proportion of phosphorylated, relative to nonphosphorylated, fibrinopeptide A, while the coagulable component contained very little of the phosphorylated peptide (AP). The high phosphate content of the defective component did not appear to be the cause of the abnormality, but may be the

  19. Fibrinogen induces endothelial cell permeability

    PubMed Central

    Tyagi, Neetu; Roberts, Andrew M.; Dean, William L.; Tyagi, Suresh C.

    2010-01-01

    Many cardiovascular and cerebrovascular disorders are accompanied by an increased blood content of fibrinogen (Fg), a high molecular weight plasma adhesion protein. Fg is a biomarker of inflammation and its degradation products have been associated with microvascular leakage. We tested the hypothesis that at pathologically high levels, Fg increases endothelial cell (EC) permeability through extracellular signal regulated kinase (ERK) signaling and by inducing F-actin formation. In cultured ECs, Fg binding to intercellular adhesion molecule-1 and to α5β1 integrin, caused phosphorylation of ERK. Subsequently, F-actin formation increased and coincided with formation of gaps between ECs, which corresponded with increased permeability of ECs to albumin. Our data suggest that formation of F-actin and gaps may be the mechanism for increased albumin leakage through the EC monolayer. The present study indicates that elevated un-degraded Fg may be a factor causing microvascular permeability that typically accompanies cardiovascular and cerebrovascular disorders. PMID:17849175

  20. Ultrastructural and biochemical analysis of fibrinogen receptors on activated thrombocytes

    SciTech Connect

    O'Toole, E.T.

    1989-01-01

    The present studies have been concerned with the role of fibrinogen and its receptor, GP IIb/IIIa, during the activation and early aggregation of pigeon thrombocytes. Thrombocytes were surface labeled with {sup 125}I then separated on SDS-PAGE. Analysis by gel autoradiography revealed major bands at MW 145 kd and 98 kd, which corresponded to human GPIIb and GPIIIa. Immunologic similarity of the pigeon and human receptor components was established by dot blot analysis using polyclonal antibodies directed against human GPIIb and GPIIIa. Pigeon fibrinogen, isolated by plasma precipitation with PEG-1000 and purified over Sepharose 4B, was used to study receptor-ligand interaction. Separation of pigeon fibrinogen on SDS-PAGE resulted in three peptides having apparent MW of 62kd, 55kd, and 47kd which are comparable to human fibrinogen. Further similarity of human and pigeon fibrinogen was verified by immonodiffusion against an antibody specific for the human protein. The role of fibrinogen and its receptor in thrombocyte function was established by turbidimetric aggregation using thrombin as an agonist under conditions requiring Ca++ and fibrinogen.

  1. Analysis of the safety and pharmacodynamics of human fibrinogen concentrate in animals

    SciTech Connect

    Beyerle, Andrea; Nolte, Marc W.; Solomon, Cristina; Herzog, Eva; Dickneite, Gerhard

    2014-10-01

    Fibrinogen, a soluble 340 kDa plasma glycoprotein, is critical in achieving and maintaining hemostasis. Reduced fibrinogen levels are associated with an increased risk of bleeding and recent research has investigated the efficacy of fibrinogen concentrate for controlling perioperative bleeding. European guidelines on the management of perioperative bleeding recommend the use of fibrinogen concentrate if significant bleeding is accompanied by plasma fibrinogen levels less than 1.5–2.0 g/l. Plasma-derived human fibrinogen concentrate has been available for therapeutic use since 1956. The overall aim of the comprehensive series of non-clinical investigations presented was to evaluate i) the pharmacodynamic and pharmacokinetic characteristics and ii) the safety and tolerability profile of human fibrinogen concentrate Haemocomplettan P® (RiaSTAP®). Pharmacodynamic characteristics were assessed in rabbits, pharmacokinetic parameters were determined in rabbits and rats and a safety pharmacology study was performed in beagle dogs. Additional toxicology tests included: single-dose toxicity tests in mice and rats; local tolerance tests in rabbits; and neoantigenicity tests in rabbits and guinea pigs following the introduction of pasteurization in the manufacturing process. Human fibrinogen concentrate was shown to be pharmacodynamically active in rabbits and dogs and well tolerated, with no adverse events and no influence on circulation, respiration or hematological parameters in rabbits, mice, rats and dogs. In these non-clinical investigations, human fibrinogen concentrate showed a good safety profile. This data adds to the safety information available to date, strengthening the current body of knowledge regarding this hemostatic agent. - Highlights: • A comprehensive series of pre-clinical investigations of human fibrinogen concentrate. • Human fibrinogen concentrate was shown to be pharmacodynamically active. • Human fibrinogen concentrate was well tolerated

  2. Aronia melanocarpa as a protector against nitration of fibrinogen.

    PubMed

    Bijak, Michał; Saluk, Joanna; Antosik, Adam; Ponczek, Michał B; Żbikowska, Halina M; Borowiecka, Marta; Nowak, Paweł

    2013-04-01

    Fibrinogen (Fg) also known as coagulation factor I represents about 4% of the total human plasma proteins. The main function of Fg is its involvement in last phase of blood coagulation cascade, when thrombin-induced conversion of dissolved plasma fibrinogen into an insoluble fibrin clot occurs. The reaction of fibrinogen with peroxynitrite causes both structural modifications and changes of the biological properties of this plasma glycoprotein. Recently, there is an increased interest in the screening of natural products present in fruits, vegetables and herbs for their possible antioxidative activities. Therefore, the aim of our study was to estimate the effect of extract from berries of Aronia melanocarpa against nitrative and oxidative damage induced by peroxynitrite. The extract from A. melanocarpa (0.5-50 μg/ml) added to Fg 10 min before peroxynitrite (100 μM) significantly inhibited both the formation of the high molecular weight protein aggregates and nitration of Fg molecule. The extract also abolished peroxynitrite-induced inhibition of fibrinogen polymerization (by 95% at 50 μg/ml). The obtained results indicate that natural extract from berries of A. melanocarpa has protective effects against peroxynitrite-induced nitrative damage of plasma fibrinogen, and therefore may contribute in the prevention of peroxynitrite-related cardiovascular or inflammatory diseases. PMID:23357800

  3. Preliminary studies of the effects of a Peruvian snake Bothrops pictus (jergon of the coast) venom upon fibrinogen.

    PubMed

    Olascoaga, M E; Zavaleta, A; Marsh, N A

    1988-01-01

    Bothrops pictus (jergon of the coast) venom has a coagulant effect in vitro on both canine fibrinogen and on human and canine plasma, with a greater affinity for canine plasma. In vivo a single dose of venom produced partial defibrinogenation in conscious dogs, plasma fibrinogen being reduced to about 60% of control values after 6 hr. PMID:3188056

  4. Rapid measurement of fibrinogen concentration in whole blood using a steel ball coagulometer

    PubMed Central

    Schlimp, Christoph J.; Khadem, Anna; Klotz, Anton; Solomon, Cristina; Hochleitner, Gerald; Ponschab, Martin; Redl, Heinz; Schöchl, Herbert

    2015-01-01

    BACKGROUND Fibrinogen plays a key role in hemostasis and is the first coagulation factor to reach critical levels in bleeding patients. Current European guidelines on the management of traumatic or perioperative bleeding recommend fibrinogen supplementation at specific threshold levels. Whole blood viscoelastic tests provide fast evaluation of fibrin deficits. Fast measurement of plasma fibrinogen concentration is not yet available. We investigated a method to rapidly determine whole blood fibrinogen concentration using standard Clauss assays and a steel ball coagulometer and provide an estimate of the “plasma-equivalent” fibrinogen concentration within minutes by adjustment of the measured whole blood fibrinogen concentration with a quickly measureable hemoglobin-derived hematocrit. METHODS The feasibility of this approach was tested with a Clauss assay using multiple porcine fresh blood samples obtained during in vivo bleeding, hemodilution, and after treatment with hemostatic therapy. Two different Clauss assays were then tested using multiple human volunteers’ blood samples diluted in vitro and supplemented with fibrinogen concentrate. Comparative measurements with fibrin-based thromboelastometry tests were performed. RESULTS Regression and Bland-Altman analyses of derived “plasma-equivalent” fibrinogen and measured plasma fibrinogen concentration was excellent in porcine and human blood samples, especially in the ranges relevant to traumatic or perioperative bleeding. CONCLUSION Fast whole blood fibrinogen measurements could be considered as an alternative to plasma fibrinogen measurement for acute bleeding management in trauma and perioperative care settings. Further studies are needed to prove this concept and determine the turnaround times for its clinical application in emergency departments and operating theaters. PMID:25742256

  5. Extraction, radioiodination, and in vivo catabolism of equine fibrinogen

    SciTech Connect

    Coyne, C.P.; Hornof, W.J.; Kelly, A.B.; O'Brien, T.R.; DeNardo, S.J.

    1985-12-01

    Equine fibrinogen was isolated and aliquots were stored frozen at -70 C before radiolabeling with 125I (half-life = 60.2 days; gamma = 35 keV, using monochloroiodine reagent. Radioiodination efficiencies were 49% to 53%, resulting in a labeled product with 98% protein-bound activity and 91% clottable radioactivity. In 6 equine in vivo investigations, plasma half-lives of 125I-labeled fibrinogen were from 4.1 to 5.2 days, corresponding to a mean daily plasma elimination rate of approximately 15%.

  6. Fibrinogen and cellular adherability on differently treated titanium as implants

    NASA Astrophysics Data System (ADS)

    Fojt, Lukáš; Klapetek, Petr; Strašák, Luděk; Vetterl, Vladimír

    2012-02-01

    Adsorption of human plasma fibrinogen, osteoblasts, and fibroblasts on differently treated titanium samples as implants were examined in this study. Titanium samples were mechanically polished, chemically etched (with and without surface material loss), and grinded. The main goal of this study is to find the best surface treatment of titanium for its possible use as implants. Atomic force microscopy was used to evaluate the adsorption of human plasma fibrinogen onto the titanium samples. Cell counting was used to determine the adherability of osteoblasts and fibroblasts on the titanium samples. Our preliminary results show that the etched titanium surface with surface material loss is the best surface treatment used in our experiments.

  7. Hormonal regulation of fibrinogen synthesis in cultured hepatocytes.

    PubMed

    Grieninger, G; Plant, P W; Liang, T J; Kalb, R G; Amrani, D; Mosesson, M W; Hertzberg, K M; Pindyck, J

    1983-06-27

    Most of what was originally known of the effects of hormones on fibrinogen synthesis was based, as noted above, on experiments involving surgical removal of endocrine glands. Some caution should be exercised when using such in vivo experiments to derive the hormonal requirements of fibrinogen synthesis, however, since multiple hormonal alterations often occur in these animals. The development of a variety of ex vivo systems has allowed investigators to more carefully control the hepatocellular environment. The work of several laboratories, including our own, has now made it clear that hormones and other agents directly stimulate hepatocellular synthesis of fibrinogen. From the studies summarized here, using chick embryo hepatocytes as a model, several generalizations emerge: Fibrinogen synthesis may be considered to be a "constitutive" liver function, since hepatocytes cultured without serum, hormones or other macromolecular supplements synthesize this protein at a basal rate for several days. Addition of certain hormones (e.g. T3, dexamethasone, insulin), individually and in physiological concentrations, elicits an increase in fibrinogen production, varying with each agent in onset, dose, minimum exposure required and accompanying effects on the synthesis of other plasma proteins. Glucocorticoids and thyroid hormones are similar in the selectivity of their stimulation (neither affects albumin or transferrin synthesis) but differ in that thyroid hormones need to be present for just a short "triggering" period. The stimulation of fibrinogen synthesis by insulin occurs only following prolonged exposure to concentrations 10-times higher than the very low doses to which albumin synthesis responds rapidly. PMID:6307104

  8. Fibrinogen stability under surfactant interaction.

    PubMed

    Hassan, Natalia; Barbosa, Leandro R S; Itri, Rosangela; Ruso, Juan M

    2011-10-01

    Differential scanning calorimetry (DSC), circular dichroism (CD), difference spectroscopy (UV-vis), Raman spectroscopy, and small-angle X-ray scattering (SAXS) measurements have been performed in the present work to provide a quantitatively comprehensive physicochemical description of the complexation between bovine fibrinogen and the sodium perfluorooctanoate, sodium octanoate, and sodium dodecanoate in glycine buffer (pH 8.5). It has been found that sodium octanoate and dodecanoate act as fibrinogen destabilizer. Meanwhile, sodium perfluorooctanoate acts as a structure stabilizer at low molar concentration and as a destabilizer at high molar concentration. Fibrinogen's secondary structure is affected by all three studied surfactants (decrease in α-helix and an increase in β-sheet content) to a different extent. DSC and UV-vis revealed the existence of intermediate states in the thermal unfolding process of fibrinogen. In addition, SAXS data analysis showed that pure fibrinogen adopts a paired-dimer structure in solution. Such a structure is unaltered by sodium octanoate and perfluoroctanoate. However, interaction of sodium dodecanoate with the fibrinogen affects the protein conformation leading to a complex formation. Taken together, all results evidence that both surfactant hydrophobicity and tail length mediate the fibrinogen stability upon interaction. PMID:21722913

  9. Thrombin and fibrinogen γ' impact clot structure by marked effects on intrafibrillar structure and protofibril packing.

    PubMed

    Domingues, Marco M; Macrae, Fraser L; Duval, Cédric; McPherson, Helen R; Bridge, Katherine I; Ajjan, Ramzi A; Ridger, Victoria C; Connell, Simon D; Philippou, Helen; Ariëns, Robert A S

    2016-01-28

    Previous studies have shown effects of thrombin and fibrinogen γ' on clot structure. However, structural information was obtained using electron microscopy, which requires sample dehydration. Our aim was to investigate the role of thrombin and fibrinogen γ' in modulating fibrin structure under fully hydrated conditions. Fibrin fibers were studied using turbidimetry, atomic force microscopy, electron microscopy, and magnetic tweezers in purified and plasma solutions. Increased thrombin induced a pronounced decrease in average protofibril content per fiber, with a relatively minor decrease in fiber size, leading to the formation of less compact fiber structures. Atomic force microscopy under fully hydrated conditions confirmed that fiber diameter was only marginally decreased. Decreased protofibril content of the fibers produced by high thrombin resulted in weakened clot architecture as analyzed by magnetic tweezers in purified systems and by thromboelastometry in plasma and whole blood. Fibers produced with fibrinogen γ' showed reduced protofibril packing over a range of thrombin concentrations. High-magnification electron microscopy demonstrated reduced protofibril packing in γ' fibers and unraveling of fibers into separate protofibrils. Decreased protofibril packing was confirmed in plasma for high thrombin concentrations and fibrinogen-deficient plasma reconstituted with γ' fibrinogen. These findings demonstrate that, in fully hydrated conditions, thrombin and fibrinogen γ' have dramatic effects on protofibril content and that protein density within fibers correlates with strength of the fibrin network. We conclude that regulation of protofibril content of fibers is an important mechanism by which thrombin and fibrinogen γ' modulate fibrin clot structure and strength. PMID:26608329

  10. Rapid extraction, radioiodination, and in vivo catabolism of 125I-labeled fibrinogen in the horse

    SciTech Connect

    Coyne, C.P.; Hornof, W.J.; Kelly, A.B.; O'Brien, T.R.; DeNardo, S.J.

    1985-12-01

    Two methods were analyzed for the rapid extraction of equine fibrinogen from fresh plasma, using ammonium sulfate-sodium phosphate buffer. Fibrinogen from each of these 2 methods was then radiolabeled with 125I (half-life = 60.2 days, gamma = 35 keV), using monochloroiodine reagent. Mean protein-bound activity was 98.5% and mean clottable radioactivity was 94.1%. Radiolabeled fibrinogen administered IV to 15 horses had an overall mean (+/- SD) plasma half-life of 4.95 +/- 0.44 days.

  11. Identification of gene-gene and gene-environment interactions within the fibrinogen gene cluster for fibrinogen levels in three ethnically diverse populations.

    PubMed

    Jeff, Janina M; Brown-Gentry, Kristin; Crawford, Dana C

    2015-01-01

    Elevated levels of plasma fibrinogen are associated with clot formation in the absence of inflammation or injury and is a biomarker for arterial clotting, the leading cause of cardiovascular disease. Fibrinogen levels are heritable with >50% attributed to genetic factors, however little is known about possible genetic modifiers that might explain the missing heritability. The fibrinogen gene cluster is comprised of three genes (FGA, FGB, and FGG) that make up the fibrinogen polypeptide essential for fibrinogen production in the blood. Given the known interaction with these genes, we tested 25 variants in the fibrinogen gene cluster for gene x gene and gene x environment interactions in 620 non-Hispanic blacks, 1,385 non-Hispanic whites, and 664 Mexican Americans from a cross-sectional dataset enriched with environmental data, the Third National Health and Nutrition Examination Survey (NHANES III). Using a multiplicative approach, we added cross product terms (gene x gene or gene x environment) to a linear regression model and declared significance at p < 0.05. We identified 19 unique gene x gene and 13 unique gene x environment interactions that impact fibrinogen levels in at least one population at p < 0.05. Over 90% of the gene x gene interactions identified include a variant in the rate-limiting gene, FGB that is essential for the formation of the fibrinogen polypeptide. We also detected gene x environment interactions with fibrinogen variants and sex, smoking, and body mass index. These findings highlight the potential for the discovery of genetic modifiers for complex phenotypes in multiple populations and give a better understanding of the interaction between genes and/or the environment for fibrinogen levels. The need for more powerful and robust methods to identify genetic modifiers is still warranted. PMID:25592583

  12. IDENTIFICATION OF GENE-GENE AND GENE-ENVIRONMENT INTERACTIONS WITHIN THE FIBRINOGEN GENE CLUSTER FOR FIBRINOGEN LEVELS IN THREE ETHNICALLY DIVERSE POPULATIONS

    PubMed Central

    Jeff, Janina M.; Brown-Gentry, Kristin; Crawford, Dana C.

    2014-01-01

    Elevated levels of plasma fibrinogen are associated with clot formation in the absence of inflammation or injury and is a biomarker for arterial clotting, the leading cause of cardiovascular disease. Fibrinogen levels are heritable with >50% attributed to genetic factors, however little is known about possible genetic modifiers that might explain the missing heritability. The fibrinogen gene cluster is comprised of three genes (FGA, FGB, and FGG) that make up the fibrinogen polypeptide essential for fibrinogen production in the blood. Given the known interaction with these genes, we tested 25 variants in the fibrinogen gene cluster for gene × gene and gene × environment interactions in 620 non-Hispanic blacks, 1,385 non-Hispanic whites, and 664 Mexican Americans from a cross-sectional dataset enriched with environmental data, the Third National Health and Nutrition Examination Survey (NHANES III). Using a multiplicative approach, we added cross product terms (gene × gene or gene × environment) to a linear regression model and declared significance at p < 0.05. We identified 19 unique gene × gene and 13 unique gene × environment interactions that impact fibrinogen levels in at least one population at p <0.05. Over 90% of the gene × gene interactions identified include a variant in the rate-limiting gene, FGB that is essential for the formation of the fibrinogen polypeptide. We also detected gene × environment interactions with fibrinogen variants and sex, smoking, and body mass index. These findings highlight the potential for the discovery of genetic modifiers for complex phenotypes in multiple populations and give a better understanding of the interaction between genes and/or the environment for fibrinogen levels. The need for more powerful and robust methods to identify genetic modifiers is still warranted. PMID:25592583

  13. Fibrinogen synthesis in serum-free hepatocyte cultures: Stimulation by glucocorticoids

    PubMed Central

    Grieninger, Gerd; Hertzberg, Kathe M.; Pindyck, Johanna

    1978-01-01

    Fibrinogen synthesis was investigated in cultures of chicken embryo hepatocytes initiated and maintained in chemically defined, serum-free medium. 11-Hydroxy glucocorticoids caused a 3-fold stimulation of fibrinogen synthesis. Half-maximal stimulation was achieved with 1 nM corticosterone or hydrocortisone, as compared with only 0.1 nM dexamethasone. Increased fibrinogen production in the presence of these glucocorticoids was characterized by a 4-hr delay in onset, a sensitivity to actinomycin D, and a requirement for the continuous presence of the steroid. Crossed immunoelectrophoresis permitted analysis of the simultaneous effects of glucocorticoids on the synthesis of more than 20 plasma proteins secreted in culture. The absence of an effect on the synthesis of most of these proteins was in sharp contrast to the 3-fold increase in fibrinogen production. Sera from a variety of animals also stimulated an increase in fibrinogen synthesis that was similar in degree but less specific than that due to glucocorticoids and that partially masked the response of the cells to the steroid hormones. The presence of an anticoagulant in the medium was found to be necessary for detection of the fibrinogen secreted in culture. Although insulin was routinely included in the chemically defined medium, the cells synthesized fibrinogen and responded to glucocorticoids in the absence of hormonal supplementation of the medium. These findings are consistent with the thesis that variations in glucocorticoid levels contribute to the regulation of fibrinogen production in the intact animal. Images PMID:281699

  14. Fibrinogen synthesis in serum-free hepatocyte cultures: stimulation by glucocorticoids.

    PubMed

    Grieninger, G; Hertzberg, K M; Pindyck, J

    1978-11-01

    Fibrinogen synthesis was investigated in cultures of chicken embryo hepatocytes initiated and maintained in chemically defined, serum-free medium. 11-Hydroxy glucocorticoids caused a 3-fold stimulation of fibrinogen synthesis. Half-maximal stimulation was achieved with 1 nM corticosterone or hydrocortisone, as compared with only 0.1 nM dexamethasone. Increased fibrinogen production in the presence of these glucocorticoids was characterized by a 4-hr delay in onset, a sensitivity to actinomycin D, and a requirement for the continuous presence of the steroid. Crossed immunoelectrophoresis permitted analysis of the simultaneous effects of glucocorticoids on the synthesis of more than 20 plasma proteins secreted in culture. The absence of an effect on the synthesis of most of these proteins was in sharp contrast to the 3-fold increase in fibrinogen production. Sera from a variety of animals also stimulated an increase in fibrinogen synthesis that was similar in degree but less specific than that due to glucocorticoids and that partially masked the response of the cells to the steroid hormones. The presence of an anticoagulant in the medium was found to be necessary for detection of the fibrinogen secreted in culture. Although insulin was routinely included in the chemically defined medium, the cells synthesized fibrinogen and responded to glucocorticoids in the absence of hormonal supplementation of the medium. These findings are consistent with the thesis that variations in glucocorticoid levels contribute to the regulation of fibrinogen production in the intact animal. PMID:281699

  15. Influence of matrix metalloproteinase-12 on fibrinogen level.

    PubMed

    Motterle, Anna; Xiao, Qingzhong; Kiechl, Stefan; Pender, Sylvia L F; Morris, Gareth E; Willeit, Johann; Caulfield, Mark J; Ye, Shu

    2012-02-01

    In vitro studies have shown that matrix metalloproteinase-12 (MMP12) can degrade fibrinogen, a clotting factor whose level predicts risk of advanced atherosclerosis and myocardial infarction. In this study, we found that mean plasma fibrinogen level was approximately 10-fold higher in MMP12 knockout mice than wildtype mice (p=0.0006). Differential allelic expression analysis of human MMP12 gene polymorphism rs17368582 in human vascular tissues showed an allele-specific effect on MMP12 expression, with one allele (T) having 1.6 fold higher expression level than the other allele (C) (p=0.0006). In a population cohort, we found that individuals homozygous for the MMP12 low expression allele had higher plasma fibrinogen levels (2.95 mg/mL compared with 2.61 mg/mL in other individuals, p=0.029) and increased risk of advanced atherosclerosis [odds ratio 6.3 (95% CI 1.9-20.8), p=0.003] and myocardial infarction [hazard ratio 5.6 (95% CI 1.7-18.3), p=0.005]. In summary, our study in mouse and humans provides in vivo evidence of an effect of MMP12 on fibrinogen level. PMID:22119538

  16. Venous ulceration, fibrinogen and fibrinolysis.

    PubMed Central

    Leach, R. D.

    1984-01-01

    The effect of long and short-term venous hypertension upon lymph fibrinogen concentrations was studied in an attempt to explain the peri-capillary deposition of fibrin reported in patients with post-phlebitic syndromes. The clearance of radioactive fibrinogen/thrombin clots from the subcutaneous tissues of rats and human volunteers was also studied. Both long- and short-term venous hypertension were found to increase fibrinogen transport across the interstitial space by more than 600%. Not only was there evidence of fibrinolytic activity in the lymph but after long-term venous hypertension alpha 2 antiplasmin activity was also detectable. Skin biopsies from the venous hypertensive ankles showed deposition of interstitial fibrin. The clearance of radioactive fibrinogen/thrombin clots from the subcutaneous tissues of the rat was found to be delayed if the rats were given epsilon amino caproic acid but it could not be increased with stanozolol. In human subjects it was found that patients with lipodermatosclerosis had delayed clot clearance and retarded blood fibrinolytic activity when compared with normal volunteers and patients with uncomplicated varicose veins. The principle cause why tall men are more subject to ulcers than short men, Dr Young conceived to be then length of the column of blood in their veins; which by its pressure, renders the legs less able to recover when hurt by any violence. Images Fig. 1 Fig. 2 Fig. 5 PMID:6742738

  17. Changes in the fibrinogen-fibrin system following a 20-hour exposure of rabbits to a magnetic field

    NASA Technical Reports Server (NTRS)

    Matskevichene, V. B.; Vitenson, T. M.

    1974-01-01

    Prolonged exposure of animals to a constant magnetic field resulted in a sharp increase in the amount of fibrinogen. The addition of EACA to the plasma of experimental rabbits as well as protamine sulfate caused an additional increase in the amount of fibrinogen. A 20-hour exposure was accompanied by phenomena of paralysis of the pelvic limbs and death of some of the animals.

  18. Fibrinogen-Induced Streptococcus mutans Biofilm Formation and Adherence to Endothelial Cells

    PubMed Central

    Lombardo Bedran, Telma Blanca; Azelmat, Jabrane; Palomari Spolidorio, Denise

    2013-01-01

    Streptococcus mutans, the predominant bacterial species associated with dental caries, can enter the bloodstream and cause infective endocarditis. The aim of this study was to investigate S. mutans biofilm formation and adherence to endothelial cells induced by human fibrinogen. The putative mechanism by which biofilm formation is induced as well as the impact of fibrinogen on S. mutans resistance to penicillin was also evaluated. Bovine plasma dose dependently induced biofilm formation by S. mutans. Of the various plasma proteins tested, only fibrinogen promoted the formation of biofilm in a dose-dependent manner. Scanning electron microscopy observations revealed the presence of complex aggregates of bacterial cells firmly attached to the polystyrene support. S. mutans in biofilms induced by the presence of fibrinogen was markedly resistant to the bactericidal effect of penicillin. Fibrinogen also significantly increased the adherence of S. mutans to endothelial cells. Neither S. mutans cells nor culture supernatants converted fibrinogen into fibrin. However, fibrinogen is specifically bound to the cell surface of S. mutans and may act as a bridging molecule to mediate biofilm formation. In conclusion, our study identified a new mechanism promoting S. mutans biofilm formation and adherence to endothelial cells which may contribute to infective endocarditis. PMID:24222906

  19. Quantitative Determination of Fibrinogen of Patients with Coronary Heart Diseases through Piezoelectric Agglutination Sensor

    PubMed Central

    Chen, Qinghai; Hua, Xing; Fu, Weiling; Liu, Dongbo; Chen, Ming; Cai, Guoru

    2010-01-01

    Fibrinogen can transform fibrin through an agglutination reaction, finally forming fibrin polymer with grid structure. The density and viscosity of the reaction system changes drastically during the course of agglutination. In this research, we apply an independently-developed piezoelectric agglutination sensor to detect the fibrinogen agglutination reaction in patients with coronary heart diseases. The terminal judgment method of determining plasma agglutination reaction through piezoelectric agglutination sensor was established. In addition, the standard curve between plasma agglutination time and fibrinogen concentration was established to determinate fibrinogen content quantitatively. The results indicate the close correlation between the STAGO paramagnetic particle method and the method of piezoelectric agglutination sensor for the detection of Fibrinogen. The correlation coefficient was 0.91 (γ = 0.91). The determination can be completed within 10 minutes. The fibrinogen concentration in the coronary heart disease group was significantly higher than that of the healthy control group (P < 0.05). The results reveal that high fibrinogen concentration is closely correlated to the incurrence, development and prognosis of coronary heart diseases. Compared with other traditional methods, the method of piezoelectric agglutination sensor has some merits such as operation convenience, small size, low cost, quick detecting, good precision and the common reacting agents with paramagnetic particle method. PMID:22294917

  20. Impact of Preemptive Fibrinogen Concentrate on Transfusion Requirements in Liver Transplantation: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial.

    PubMed

    Sabate, A; Gutierrez, R; Beltran, J; Mellado, P; Blasi, A; Acosta, F; Costa, M; Reyes, R; Torres, F

    2016-08-01

    We hypothesized that preemptive fibrinogen administration to obtain an initial plasma level of 2.9 g/L would reduce transfusion requirements in liver transplantation. A randomized, multicenter, hemoglobin-stratified, double-blind, fibrinogen-versus-saline-controlled trial was conducted. The primary end point was the percentage of patients requiring red blood cells. We evaluated 51 patients allocated to fibrinogen and 48 allocated to saline; the primary end point was assessed using data for 92 patients because the electronic record forms were offline for three patients in the fibrinogen group and four in the saline group. We injected a median of 3.54 g fibrinogen preemptively in the fibrinogen group. Nine patients in the saline group (20.9%) required fibrinogen at graft reperfusion (compared with one patient [2.1%] in the fibrinogen group; p = 0.005). Blood was transfused to 52.9% (95% confidence interval [CI] 42.5-63.3%) in the fibrinogen group and 42.74% (95% CI 28.3-57.2%) in the saline group (p = 0.217). Relative risk for blood transfusion was 0.80 (95% CI 0.57-1.13). Thrombotic events occurred in one patient (2.1%) and five patients (11.4%) in the fibrinogen and saline groups, respectively. Seven patients (14.6%) in the fibrinogen group and nine (20.3%) in the saline group required reoperation. Preemptive administration of fibrinogen concentrate did not influence transfusion requirements. PMID:26880105

  1. Optimized Preparation Method of Platelet-Concentrated Plasma and Noncoagulating Platelet-Derived Factor Concentrates: Maximization of Platelet Concentration and Removal of Fibrinogen

    PubMed Central

    Araki, Jun; Jona, Masahiro; Eto, Hitomi; Aoi, Noriyuki; Kato, Harunosuke; Suga, Hirotaka; Doi, Kentaro; Yatomi, Yutaka

    2012-01-01

    Abstract Platelet-rich plasma (PRP) has been clinically used as an easily prepared growth factor cocktail that can promote wound healing, angiogenesis, and tissue remodeling. However, the therapeutic effects of PRP are still controversial, due partly to the lack of optimized and standardized preparation protocols. We used whole blood (WB) samples to optimize the preparation protocols for PRP, white blood cell-containing (W-PRP), platelet-concentrated plasma (PCP), and noncoagulating platelet-derived factor concentrate (PFC). PRP and W-PRP were most efficiently collected by 10 min centrifugation in a 15-mL conical tube at 230–270 g and 70 g, respectively. To prepare PCP, platelets were precipitated by centrifugation of PRP at >2300 g, 90% of supernatant plasma was removed, and the platelets were resuspended. For preparation of noncoagulating PFC, the supernatant was replaced with one-tenth volume of saline, followed by platelet activation with thrombin. Platelet (before activation) and platelet-derived growth factor (PDGF)-BB (after activation) concentrations in PCP were approximately 20 times greater than those in WB, whereas PFC contained a 20-times greater concentration of platelets before platelet activation and a 50-times greater concentration of PDGF-BB without formation of a fibrin gel after platelet activation than WB. Surprisingly, total PDGF-BB content in the PFC was twice that of activated WB, which suggested that a substantial portion of the PDGF-BB became trapped in the fibrin glue, and replacement of plasma with saline is crucial for maximization of platelet-derived factors. As an anticoagulant, ethylene di-amine tetra-acetic acid disodium inhibited platelet aggregation more efficiently than acid citrate dextrose solution, resulting in higher nonaggregated platelet yield and final PDGF-BB content. These results increase our understanding of how to optimize and standardize preparation of platelet-derived factors at maximum concentrations. PMID

  2. Adsorption and functionality of fibrinogen on triblock copolymer-coated surfaces

    NASA Astrophysics Data System (ADS)

    O'Connor, Stephen Moss

    To assess the influence of the surface microenvironment on the adsorption and biologic activity of fibrinogen, a series of poly(ethylene oxide)/poly(propylene oxide) triblock copolymers were adsorbed to solid, hydrophobic polystyrene-divinylbenzene beads. The copolymers, which were of the form PEOsb{b}PPOsb{a}PEOsb{b}, varied in their hydrophile/lipophile balances (HLB) due only to differences in their PEO chain length (5 to 129 EO units) as the hydrophobic PPO core segment was of fixed length (56 or 69 PO units). The surface coverage of copolymers was determined first and after exposing the beads to fibrinogen or to human plasma, the total amount of protein adsorbed to their surface was measured. The functionality of fibrinogen bound to copolymer-modified beads was assessed in terms of fibrin clot formation and by the adherence of macrophages (THP-1 tumor cells). Enzymatic processing was used to probe the surface orientation of fibrinogen. The copolymers appear to adsorb in an expanded fashion, a conclusion supported by surface pressure-area isotherms of the copolymers spread at the air-water interface. As compared to copolymer-free surfaces, protein adsorption decreases by up to 90% as the PEO chain length of the copolymers increases. The copolymer coatings appear to lower fibrinogen adsorption by limiting the available surface area. On surfaces coated with the hydrophobic versions of the copolymers, the biologic assays demonstrate that fibrinogen is as reactive/coagulable as for surfaces with saturated coverages of fibrin despite that these copolymer-coated surfaces have 60% less fibrinogen adsorbed to them. When adsorbed at the same low surface concentration in the absence of copolymer, fibrinogen is not active. Enzymatic processing of bound fibrinogen suggests that the presence of the copolymers promote the adsorption of the protein in end-on fashion. It is proposed here, that when adsorbed end-on, fibrinogen is functional because its reactive sites are

  3. Fibrinogen and red blood cells in venous thrombosis

    PubMed Central

    Aleman, Maria M.; Walton, Bethany L.; Byrnes, James R.; Wolberg, Alisa S.

    2014-01-01

    Deep vein thrombosis and pulmonary embolism, collectively termed venous thromboembolism (VTE), affect over 1 million Americans each year. VTE is triggered by inflammation and blood stasis leading to the formation of thrombi rich in fibrin and red blood cells (RBCs). However, little is known about mechanisms regulating fibrin and RBC incorporation into venous thrombi, or how these components mediate thrombus size or resolution. Both elevated circulating fibrinogen (hyperfibrinogenemia) and abnormal fibrin(ogen) structure and function, including increased fibrin network density and resistance to fibrinolysis, have been observed in plasmas from patients with VTE. Abnormalities in RBC number and/or function have also been associated with VTE risk. RBC contributions to VTE are thought to stem from their effects on blood viscosity and margination of platelets to the vessel wall. More recent studies suggest RBCs also express phosphatidylserine, support thrombin generation, and decrease fibrinolysis. RBC interactions with fibrin(ogen) and cells, including platelets and endothelial cells, may also promote thrombus formation. The contributions of fibrin(ogen) and RBCs to the pathophysiology of VTE warrants further investigation. PMID:24759140

  4. FbsA-Driven Fibrinogen Polymerization: A Bacterial ``Deceiving Strategy''

    NASA Astrophysics Data System (ADS)

    Pierno, Matteo; Maravigna, Laura; Piazza, Roberto; Visai, Livia; Speziale, Pietro

    2006-01-01

    We show that FbsA, a cell wall protein of the bacterium Streptococcus agalactiae, promotes large-scale aggregation of human plasma fibrinogen, leading to the formation of a semiflexible polymerlike network. This extensive aggregation process takes place not only in solution, but also on FbsA-functionalized colloidal particles, and leads to the formation of a thick layer on the bacterial cell wall itself, which becomes an efficient mask against phagocytosis.

  5. How to Assess Fibrinogen Levels and Fibrin Clot Properties in Clinical Practice?

    PubMed

    Undas, Anetta

    2016-06-01

    Fibrin formed from fibrinogen is the main component of thrombi. Clot structure is characterized by fiber thickness and pore size, which differs within a given clot and between individuals. Plasma clot architecture is largely determined by the quantity and quality of fibrinogen. Plasma fibrinogen concentrations are most commonly measured in citrated plasma using the Clauss method. However, several factors, including instrument type and reagent, may affect results. Other approaches to express the ability of fibrinogen to clot involve prothrombin time-derived or clottable protein assays, while fibrinogen antigen levels in clinical settings are measured using immunological or precipitation assays. Fibrin clot permeability (reflected by the Darcy constant, K s) being proportional to a buffer volume percolating through a clot under a given hydrostatic pressure is now the most commonly used measure of clot structure. Low K s values indicating tightly packed fibrin structure have been shown to be associated with venous and arterial thrombotic complications, while high K s might contribute to bleeding disorders. The measurement of K s, however, is not standardized and validated. This review summarizes the current knowledge on practical aspects of the measurement of fibrinogen levels and K s in patients. PMID:27071050

  6. Mice expressing a mutant form of fibrinogen that cannot support fibrin formation exhibit compromised antimicrobial host defense

    PubMed Central

    Prasad, Joni M.; Gorkun, Oleg V.; Raghu, Harini; Thornton, Sherry; Mullins, Eric S.; Palumbo, Joseph S.; Ko, Ya-Ping; Höök, Magnus; David, Tovo; Coughlin, Shaun R.; Degen, Jay L.

    2015-01-01

    Fibrin(ogen) is central to hemostasis and thrombosis and also contributes to multiple physiologic and pathologic processes beyond coagulation. However, the precise contribution of soluble fibrinogen vs insoluble fibrin matrices to vascular integrity, tissue repair, inflammation, and disease has been undefined and unapproachable. To establish the means to distinguish fibrinogen- and fibrin-dependent processes in vivo, FibAEK mice were generated that carry normal levels of circulating fibrinogen but lack the capacity for fibrin polymer formation due to a germ-line mutation in the Aα chain thrombin cleavage site. Homozygous FibAEK mice developed to term and exhibited postnatal survival superior to that of fibrinogen-deficient mice. Unlike fibrinogen-deficient mice, platelet-rich plasma from FibAEK mice supported normal platelet aggregation in vitro, highlighting that fibrinogenAEK retains the functional capacity to support interactions with platelets. Thrombin failed to release fibrinopeptide-A from fibrinogenAEK and failed to induce polymer formation with FibAEK plasma or purified fibrinogenAEK in 37°C mixtures regardless of incubation time. FibAEK mice displayed both an absence of fibrin polymer formation following liver injury, as assessed by electron microscopy, and a failure to generate stable occlusive thrombi following FeCl3 injury of carotid arteries. FibAEK mice exhibited a profound impediment in Staphylococcus aureus clearance following intraperitoneal infection similar to fibrinogen-deficient mice, yet FibAEK mice displayed a significant infection dose-dependent survival advantage over fibrinogen-deficient mice following peritonitis challenge. Collectively, these findings establish for the first time that fibrin polymer is the molecular form critical for antimicrobial mechanisms while simultaneously highlighting biologically meaningful contributions and functions of the soluble molecule. PMID:26228483

  7. Mice expressing a mutant form of fibrinogen that cannot support fibrin formation exhibit compromised antimicrobial host defense.

    PubMed

    Prasad, Joni M; Gorkun, Oleg V; Raghu, Harini; Thornton, Sherry; Mullins, Eric S; Palumbo, Joseph S; Ko, Ya-Ping; Höök, Magnus; David, Tovo; Coughlin, Shaun R; Degen, Jay L; Flick, Matthew J

    2015-10-22

    Fibrin(ogen) is central to hemostasis and thrombosis and also contributes to multiple physiologic and pathologic processes beyond coagulation. However, the precise contribution of soluble fibrinogen vs insoluble fibrin matrices to vascular integrity, tissue repair, inflammation, and disease has been undefined and unapproachable. To establish the means to distinguish fibrinogen- and fibrin-dependent processes in vivo, Fib(AEK) mice were generated that carry normal levels of circulating fibrinogen but lack the capacity for fibrin polymer formation due to a germ-line mutation in the Aα chain thrombin cleavage site. Homozygous Fib(AEK) mice developed to term and exhibited postnatal survival superior to that of fibrinogen-deficient mice. Unlike fibrinogen-deficient mice, platelet-rich plasma from Fib(AEK) mice supported normal platelet aggregation in vitro, highlighting that fibrinogen(AEK) retains the functional capacity to support interactions with platelets. Thrombin failed to release fibrinopeptide-A from fibrinogen(AEK) and failed to induce polymer formation with Fib(AEK) plasma or purified fibrinogen(AEK) in 37°C mixtures regardless of incubation time. Fib(AEK) mice displayed both an absence of fibrin polymer formation following liver injury, as assessed by electron microscopy, and a failure to generate stable occlusive thrombi following FeCl3 injury of carotid arteries. Fib(AEK) mice exhibited a profound impediment in Staphylococcus aureus clearance following intraperitoneal infection similar to fibrinogen-deficient mice, yet Fib(AEK) mice displayed a significant infection dose-dependent survival advantage over fibrinogen-deficient mice following peritonitis challenge. Collectively, these findings establish for the first time that fibrin polymer is the molecular form critical for antimicrobial mechanisms while simultaneously highlighting biologically meaningful contributions and functions of the soluble molecule. PMID:26228483

  8. Fibrinogen and catheter-directed thrombolysis.

    PubMed

    Ross, Reagan L; Beck, Adam W

    2014-12-01

    Fibrinogen is a complex glycoprotein that is known to play a significant role in the process of thrombus formation and evolution, and has been linked to the pathophysiology of atherosclerosis. Given the importance of fibrinogen in these processes, it has been evaluated as a biomarker for atherosclerotic disease and as a marker during treatment for venous and arterial thrombosis. Here we describe the expansive role that fibrinogen plays in human physiology. PMID:26073829

  9. Association of Fibrinogen with Severity of Stable Coronary Artery Disease in Patients with Type 2 Diabetic Mellitus

    PubMed Central

    Hong, Li-Feng; Li, Xiao-Lin; Luo, Song-Hui; Guo, Yuan-Lin; Zhu, Cheng-Gang; Qing, Ping; Wu, Na-Qiong; Li, Jian-Jun

    2014-01-01

    Background. Some studies have suggested a relation of plasma fibrinogen to the severity of coronary artery disease (CAD). However, whether plasma fibrinogen can predict the presence and severity of CAD in patients with diabetes mellitus has not been determined. Methods. A total of consecutive 373 diabetic patients with typical angina pectoris who received coronary angiography were enrolled and classified into three groups by tertiles of Gensini score (GS, low group <8; intermediate group 8~28; high group >28). The relationship between fibrinogen and GS was evaluated. Results. There were correlations of fibrinogen with hemoglobin A1c, C-reactive protein, and GS (r = 0.17, r = 0.52, and r = 0.21, resp.; all P < 0.001). Area under the receivers operating characteristic curve of fibrinogen was 0.62 (95% CI 0.56–0.68, P < 0.001) for predicting a high GS. Multivariate analysis suggested that plasma fibrinogen was an independent predictor of a high GS for diabetic patients (OR = 1.40, 95% CI 1.04–1.88, and P = 0.026) after adjusting for traditional risk factors of CAD. Conclusions. The present data indicated that plasma fibrinogen, a readily measurable systematic inflammatory marker, appeared to be an independent predictor for the severity of CAD in diabetic patients. PMID:24803720

  10. Association of serum calcium concentrations with fibrinogen and homocysteine in nondiabetic Korean subjects

    PubMed Central

    Cho, Hyun Sun; Lee, Sung Won; Shin, Juyoung; Moon, Sung Dae; Han, Je Ho; Cha, Bong Yun; Kim, Eun Sook

    2016-01-01

    Abstract Considerable evidence shows that increased serum calcium levels are associated with metabolic disorders, cardiovascular disease, and increased mortality. This study investigated whether serum calcium, within a normal range, is significantly associated with serum fibrinogen and homocysteine, markers of increased cardiovascular disease risk in nondiabetic Korean subjects. A cross-sectional analysis was performed on 1096 subjects (mean age, 55.1 ± 11.1 years; 36.1% women) undergoing a general health checkup. Serum biochemistry was analyzed including serum albumin-corrected calcium (Cac), insulin resistance (IR, using homeostasis model assessment [HOMA]), fibrinogen, and homocysteine. Compared with patients within the lowest Cac quartile, those with higher Cac levels had increased fibrinogen and homocysteine levels as well as an increased proportion of smoking, dyslipidemia, and HOMA-IR. Correlation analyses revealed linear relationships for Cac with fibrinogen and homocysteine in both genders. After adjustment for confounding factors, serum Cac was significantly associated with high fibrinogen (odds ratio [OR] for the highest vs the lowest quartile = 1.76, 95% confidence interval [CI] = 1.09–2.83, P = 0.02) and homocysteine (OR = 1.83, 95% CI = 1.07–3.11, P = 0.027). Multivariate regression models showed that Cac was linearly associated with fibrinogen (standardized β = 0.14, P < 0.001) and homocysteine (standardized β = 0.07, P = 0.009). High normal calcium concentrations were independently associated with increased levels of fibrinogen and homocysteine. Further investigation is needed to validate whether slightly increased calcium levels within the normal range indicate a higher risk of cardiovascular disease. PMID:27310988

  11. Fibrinogen Degradation Products and Periodontitis: Deciphering the Connection

    PubMed Central

    2015-01-01

    Introduction Fibrinogen degradation products (e.g. D-dimer) arise from digested fibrin clots and fibrinogen. Elevated concentrations accompany activation of coagulation and fibrinolysis and indicate chronic inflammatory diseases. D-Dimer tests are a quick, noninvasive method to rule out abnormal clotting. Periodontitis strongly affects the haemostatic system and evokes a procoagulant state. Correlation of chronic periodontitis with early indicators of disease (biomarkers) might be useful. Aim The aim of the study was to examine whether the plasma D-dimer concentration reflects the progression of chronic periodontitis and the beneficial effect of periodontal therapy. Materials and Methods Forty randomly selected subjects were divided into four groups, Group I: 10 healthy subjects, Group II: 10 with mild periodontitis, Group III: 10 with moderate periodontitis, Group IV: 10 with severe periodontitis. After thorough dental and periodontal examination, 3 mL of venous blood was collected for measurement of fibrinogen degradation products. Results The patients with moderate and chronic periodontitis exhibited high concentrations of D-dimer (mean value 434.98–535.52 mcg/mL), whereas subjects with mild or no periodontitis exhibited values of 329.78–211.29 mcg/mL. Concentrations of D-dimer were significantly reduced after therapy of all classes of periodontitis. Conclusion Periodontal treatment can reduce amount of D-dimer in the plasma. A higher than normal concentration is observed in chronic periodontitis. PMID:26816985

  12. A comparison of the fibrinogen receptor distribution on adherent platelets using both soluble fibrinogen and fibrinogen immobilized on gold beads.

    PubMed

    Estry, D W; Mattson, J C; Mahoney, G J; Oesterle, J R

    1991-04-01

    The distribution of fibrinogen receptors was determined on the surface of adherent platelets using both direct labeling with the ligand fibrinogen which was immobilized on gold particles (Fg-Au) and indirect immunogold (Ig-Au) labeling of bound soluble fibrinogen identified with a rabbit polyclonal anti-fibrinogen antibody. Two distinctly different patterns of labeling were obtained and appeared to depend on whether solid phase fibrinogen (Fg-Au) or soluble phase released fibrinogen were bound to the membrane receptor. The membrane-bound Fg-Au reorganized in patterns that closely mimicked the organization of the underlying cytoskeleton. In approximately 18% of the adherent platelets, Fg-Au was seen in channels or vesicle-like structures lying deep to the platelet surface suggesting internalization into the open canalicular system and/or endocytosis. The labeling pattern obtained when identifying the location of membrane-bound soluble released fibrinogen by Ig-Au was diffuse and lacked the organizational patterns characteristic of Fg-Au. Unlike the Fg-Au probe, early dendritic platelets were heavily labeled by the soluble phase fibrinogen using the Ig-Au technique. Although the label covered the entire exposed platelet membrane in fully spread platelets, labeling over the peripheral web was more dense than that over the intermediate or granulomere zone. The diffuse organization and heavier peripheral distributional pattern of the glycoprotein IIb-IIIa (GP IIb-IIIa) receptor in fixed, adherent platelets, was also seen with the GP IIb-IIIa receptor-specific antibody AP-2. The binding of both the Fg-Au and Ig-Au were inhibited using the tetrapeptide Arg-Gly-Asp-Ser (RGDS) (93% and 98% inhibition, respectively), AP-2 (98% and 97%, respectively) and platelets from patients with Glanzmann's thrombasthenia (GT) (99% and 98%, respectively). The data presented provides the first report that receptor reorganization, following binding of fibrinogen, appears to be related to

  13. Fibrinogen and rhegmatogenous retinal detachment: a pilot prospective study

    PubMed Central

    Theocharis, IP

    2010-01-01

    Purpose: To examine the correlation, if any, between fibrinogen plasma levels (FPL) and the clinical features of rhegmatogenous retinal detachment (RRD). Methods: FPL were measured preoperatively in 33 patients with primary RRD. Patient characteristics and detachment features such as the numbers of breaks and the extent of the detachment were recorded; Results: No statistically significant correlation was found between FPL and the number of breaks. A statistically significant correlation was found between FPL and the extent of the RRD, even if the influence of the number of breaks was excluded. Conclusions: FPL correlate with retinal detachment extent, which implicates an acute inflammatory response to detachment traumatic phenomenon or a role of the fibrinogen molecule in retinal adhesiveness. PMID:20186280

  14. Neprilysin Inhibits Coagulation through Proteolytic Inactivation of Fibrinogen.

    PubMed

    Burrell, Matthew; Henderson, Simon J; Ravnefjord, Anna; Schweikart, Fritz; Fowler, Susan B; Witt, Susanne; Hansson, Kenny M; Webster, Carl I

    2016-01-01

    Neprilysin (NEP) is an endogenous protease that degrades a wide range of peptides including amyloid beta (Aβ), the main pathological component of Alzheimer's disease (AD). We have engineered NEP as a potential therapeutic for AD but found in pre-clinical safety testing that this variant increased prothrombin time (PT) and activated partial thromboplastin time (APTT). The objective of the current study was to investigate the effect of wild type NEP and the engineered variant on coagulation and define the mechanism by which this effect is mediated. PT and APTT were measured in cynomolgus monkeys and rats dosed with a human serum albumin fusion with an engineered variant of NEP (HSA-NEPv) as well as in control plasma spiked with wild type or variant enzyme. The coagulation factor targeted by NEP was determined using in vitro prothrombinase, calibrated automated thrombogram (CAT) and fibrin formation assays as well as N-terminal sequencing of fibrinogen treated with the enzyme. We demonstrate that HSA-NEP wild type and HSA-NEPv unexpectedly impaired coagulation, increasing PT and APTT in plasma samples and abolishing fibrin formation from fibrinogen. This effect was mediated through cleavage of the N-termini of the Aα- and Bβ-chains of fibrinogen thereby significantly impairing initiation of fibrin formation by thrombin. Fibrinogen has therefore been identified for the first time as a substrate for NEP wild type suggesting that the enzyme may have a role in regulating fibrin formation. Reductions in NEP levels observed in AD and cerebral amyloid angiopathy may contribute to neurovascular degeneration observed in these conditions. PMID:27437944

  15. Neprilysin Inhibits Coagulation through Proteolytic Inactivation of Fibrinogen

    PubMed Central

    Burrell, Matthew; Henderson, Simon J.; Ravnefjord, Anna; Schweikart, Fritz; Fowler, Susan B.; Witt, Susanne; Hansson, Kenny M.; Webster, Carl I.

    2016-01-01

    Neprilysin (NEP) is an endogenous protease that degrades a wide range of peptides including amyloid beta (Aβ), the main pathological component of Alzheimer’s disease (AD). We have engineered NEP as a potential therapeutic for AD but found in pre-clinical safety testing that this variant increased prothrombin time (PT) and activated partial thromboplastin time (APTT). The objective of the current study was to investigate the effect of wild type NEP and the engineered variant on coagulation and define the mechanism by which this effect is mediated. PT and APTT were measured in cynomolgus monkeys and rats dosed with a human serum albumin fusion with an engineered variant of NEP (HSA-NEPv) as well as in control plasma spiked with wild type or variant enzyme. The coagulation factor targeted by NEP was determined using in vitro prothrombinase, calibrated automated thrombogram (CAT) and fibrin formation assays as well as N-terminal sequencing of fibrinogen treated with the enzyme. We demonstrate that HSA-NEP wild type and HSA-NEPv unexpectedly impaired coagulation, increasing PT and APTT in plasma samples and abolishing fibrin formation from fibrinogen. This effect was mediated through cleavage of the N-termini of the Aα- and Bβ-chains of fibrinogen thereby significantly impairing initiation of fibrin formation by thrombin. Fibrinogen has therefore been identified for the first time as a substrate for NEP wild type suggesting that the enzyme may have a role in regulating fibrin formation. Reductions in NEP levels observed in AD and cerebral amyloid angiopathy may contribute to neurovascular degeneration observed in these conditions. PMID:27437944

  16. Over 50 Years of Fibrinogen Concentrate.

    PubMed

    Costa-Filho, Rubens; Hochleitner, Gerald; Wendt, Michael; Teruya, Alexandre; Spahn, Donat R

    2016-03-01

    March 2013 represented the 50th anniversary of the first license granted for a fibrinogen concentrate. In this review, we look at the history of bleeding management that led to the development of fibrinogen concentrate, discuss its current use, and consider future developments for this product. PMID:26294722

  17. Over 50 Years of Fibrinogen Concentrate

    PubMed Central

    Hochleitner, Gerald; Wendt, Michael; Teruya, Alexandre; Spahn, Donat R.

    2015-01-01

    March 2013 represented the 50th anniversary of the first license granted for a fibrinogen concentrate. In this review, we look at the history of bleeding management that led to the development of fibrinogen concentrate, discuss its current use, and consider future developments for this product. PMID:26294722

  18. Fibrinogen

    MedlinePlus

    ... or secondary Hemophilia A Hemophilia B Placenta abruption - definition Update Date 1/27/2015 Updated by: Yi- ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  19. Platelet Glycoproteins and Fibrinogen in Recovery from Idiopathic Sudden Hearing Loss

    PubMed Central

    Gorzelniak, Kerstin; Bremer, Alexis; Rudack, Claudia; Walter, Michael

    2014-01-01

    Background The pathomechanism and location of idiopathic sudden sensorineural hearing loss (ISSHL) is unclear. In a previous case-control study, we found elevated fibrinogen concentrations and a higher prevalence of T allele carriers of the glycoprotein (Gp) Ia C807T polymorphism in ISSHL patients. Methodology 127 patients with ISSHL (mean age 53.3 years, 48.8% females), who underwent a standard therapy with high dose steroids, pentoxifyllin and sterofundine over 8 days were included. We examined the influence of GpIa genotype and fibrinogen (BclI-, A312-, HaeIII-) genotype and fibrinogen plasma levels on hearing recovery after 8 weeks (change from baseline: 0 dB  =  no recovery, >0 to 10 dB = moderate recovery, >10 dB = good recovery). In a subsample of 59 patients with ISSHL, we further studied the association of platelet glycoprotein GpIa, Ib and IIIa densities on hearing recovery as well as the possible effect-modification of platelet glycoproteins on hearing recovery by plasma fibrinogen. Results In univariate analysis, neither the GpIa genotype nor fibrinogen genotype (all p>0.1) but lower fibrinogen levels (p = 0.029), less vertigo (p = 0.002) and lower GpIIIa receptor density (p = 0.037, n = 59) were associated with hearing recovery. In multivariate analysis, fibrinogen significantly modified the effect of GPIa receptor density on good hearing recovery (effect-modification on multiplicative scale OR = 0.45 (95% confidence interval (0.21–0.94)), p = 0.03). GPIb receptor density below the mean was associated with a 2-fold increase in good hearing recovery both in patients with fibrinogen levels above (p = 0.04) as well as in patients with fibrinogen levels below the mean (p = 0.06). There was no indication for an effect-modification (p = 0.97). Conclusions The findings suggest a vascular/rheological origin of ISSHL with unique features of thrombosis in the inner ear artery that may include complex

  20. The development of radioimmunoassays for fibrinogen degradation products: fragments D and E.

    PubMed

    Gordon, Y B; Martin, M J; Landon, J; Chard, T

    1975-01-01

    Fibrinogen degradation products, fragment D (FgD) and fragment E (FgE) have been measured in human serum by specific radioimmunoassays. In addition, the appearance of a neoantigenic determinant on FgD, revealed when fibrinogen is degraded by plasmin has been utilized to develop a specific radioimmunoassay for FgD in plasma (FgDneo). The reagents and conditions used in each assay are described in detail. The mean specific activity was 144 muCi/mug for 125I-labelled FgE and 82 muCi/mug for 125I-labelled FgD. Separation of antibody bound and free antigen was achieved using second antibody. The detection limits of the FgE, FgD and FgDneo assays were 0.8, 1.0 and 6.2 ng/ml respectively. The specificity of each assay with respect to fibrinogen and its degradation fragments has been assessed. Fibrinogen and fragment X cross-reacted markedly in both the FgE and FgD assays, whereas the cross-reaction of fibrinogen was abolished in the FgDneo assay, while the cross-reaction of fragment X was 10%, indicating gradual emergence of the neoantigenic site during digestion of fibriogen. The sensitivity, precision, and specificity of the radioimmunoassay systems described have major advantages over the existing procedures for the measurement of fibrinogen degradation products. PMID:1201195

  1. Tumor response and survival in patients with advanced non-small-cell lung cancer: the predictive value of chemotherapy-induced changes in fibrinogen

    PubMed Central

    2012-01-01

    Background Hyperfibrinogenemia is a common problem associated with various carcinomas, and is accompanied by hypercoagulablity. In advanced non-small-cell lung cancer (NSCLC) it remains unclear whether or not chemotherapy-induced changes in fibrinogen level relate to chemotherapeutic response and prognosis. The purposes of this study were to: 1) analyze the association between chemotherapy-induced changes in plasma fibrinogen level and the chemotherapeutic response after the first two courses of standard first-line platinum-based chemotherapy; and 2) evaluate the prognostic significance of the basal plasma fibrinogen level in patients with advanced NSCLC. Methods In this retrospective study, the data from 160 patients with advanced NSCLC were collected. The association between the changes in fibrinogen and the response to chemotherapy, or between the pre-and post-chemotherapy fibrinogen levels and patient clinical characteristics, were analyzed using SPSS software. In addition, the prognostic value of pre-chemotherapy fibrinogen levels was assessed. Results The median pre-chemotherapy plasma fibrinogen level was 4.4 g/L. Pre-chemotherapy plasma fibrinogen levels correlated significantly with gender (p = 0.041). Post-chemotherapy plasma fibrinogen levels correlated with gender (p = 0.023), age (p = 0.018), ECOG (p = 0.002) and tumor response (p = 0.049). Plasma fibrinogen levels markedly decreased after chemotherapy in 98 (61.25 %) patients with pre-chemotherapy hyperfibrinogenemia (p = 0.008); and in this population there was a significant link between the decrease in fibrinogen level, and initial partial response (PR; p = 0.017) and stable disease (SD; p = 0.031). Univariate and multivariate analysis revealed that higher levels of fibrinogen (≥4.4 g/L) and ECOG 1 were positively associated with shorter overall survival (OS). CEA and CA125 also decreased significantly (p =0.015, p =0.000) in DCR group after chemotherapy. Conclusions This study showed that the

  2. Recovery of fibrinogen concentrate after intraosseous application is equivalent to the intravenous route in a porcine model of hemodilution

    PubMed Central

    Schlimp, Christoph J.; Solomon, Cristina; Keibl, Claudia; Zipperle, Johannes; Nürnberger, Sylvia; Öhlinger, Wolfgang; Redl, Heinz; Schöchl, Herbert

    2014-01-01

    BACKGROUND Fibrinogen concentrate is increasingly considered as a hemostatic agent for trauma patients experiencing bleeding. Placing a venous access is sometimes challenging during severe hemorrhage. Intraosseous access may be considered instead. Studies of intraosseous infusion of coagulation factor concentrates are limited. We investigated in vivo recovery following intraosseous administration of fibrinogen concentrate and compared the results with intravenous administration. METHODS This study was performed on 12 pigs (mean [SD] body weight, 34.1 [2.8] kg). Following controlled blood loss (35 mL/kg) and fluid replacement with balanced crystalloid solution, intraosseous (n = 6) administration of fibrinogen concentrate (80 mg per kilogram of bodyweight) in the proximal tibia was compared with intravenous (n = 6) administration of the same dose (fibrinogen infusion time approximately 5 minutes in both groups). The following laboratory parameters were assessed: blood cell count, prothrombin time index, activated partial thromboplastin time, and plasma fibrinogen concentration (Clauss assay). Coagulation status was also assessed by thromboelastometry. RESULTS All tested laboratory parameters were comparable between the intraosseous and intravenous groups at baseline, hemodilution, and 30 minutes after fibrinogen concentrate administration. In vivo recovery of fibrinogen was also similar in the two groups (89% [23%] and 91% [22%], respectively). There were no significant between-group differences in any of the thromboelastometric parameters. Histologic examination indicated no adverse effects on the tissue surrounding the intraosseous administration site. CONCLUSION This study suggests that intraosseous administration of fibrinogen concentrate results in a recovery of fibrinogen similar to that of intravenous administration. The intraosseous route of fibrinogen concentrate could be a valuable alternative in situations where intravenous access is not feasible or would

  3. The fibrinogen γA/γ’ isoform does not promote acute arterial thrombosis in mice

    PubMed Central

    Walton, Bethany L; Getz, Todd M; Bergmeier, Wolfgang; Lin, Feng-Chang; de Willige, Shirley Uitte; Wolberg, Alisa S

    2014-01-01

    Background Elevated plasma fibrinogen associates with arterial thrombosis in humans and promotes thrombosis in mice by increasing fibrin formation and thrombus fibrin content. Fibrinogen is composed of six polypeptide chains: (Aα, Bβ, and γ)2. Alternative splicing of the γ chain leads to a dominant form (γA/γA) and a minor species (γA/γ’). Epidemiologic studies have detected elevated γA/γ’ fibrinogen in patients with arterial thrombosis, suggesting this isoform promotes thrombosis. However, in vitro data show that γA/γ’ is anticoagulant due to its ability to sequester thrombin, and suggest its expression is upregulated in response to inflammatory processes. Objective To determine whether γA/γ’ fibrinogen is prothrombotic in vivo. Methods We separated γA/γA and γA/γ’ fibrinogen from human plasma-purified fibrinogen and determined effects on in vitro plasma clot formation, and in vivo thrombus formation and circulating thrombin-antithrombin complexes in mice. Results and Conclusions Both γA/γA and γA/γ’ fibrinogen were cleaved by murine and human thrombin and were incorporated into murine and human clots. When γA/γA or γA/γ’ was spiked into plasma, γA/γA increased the fibrin formation rate to a greater extent than γA/γ’. In mice, compared to controls, γA/γA infusion shortened the time to carotid artery occlusion, whereas γA/γ’ infusion did not. Additionally, γA/γ’ infusion led to lower levels of plasma thrombin-antithrombin complexes following arterial injury, whereas γA/γA infusion did not. These data suggest that γA/γ’ binds thrombin in vivo, and decreases prothrombotic activity. Together, these findings indicate that elevated levels of γA/γA fibrinogen promote arterial thrombosis in vivo, whereas γA/γ’ does not. PMID:24916154

  4. Energetics of thrombin-fibrinogen interaction.

    PubMed

    Hopfner, K P; Di Cera, E

    1992-11-24

    The kinetic mechanism of thrombin-fibrinogen interaction has been elucidated by steady-state measurements of synthetic substrate hydrolysis by human alpha-thrombin in the presence of human fibrinogen used as a competitive inhibitor and sucrose used as a viscogenic agent. Sucrose greatly affects the FKm for thrombin-fibrinogen interaction, without altering the intrinsic properties of the system. Under conditions of pH 7.5 and 0.1 M NaCl, fibrinogen behaves like a sticky substrate for thrombin, with acylation being comparable to dissociation in the temperature range 20-37 degrees C. In the same temperature range, deacylation is much faster than acylation. The van't Hoff enthalpy of binding for thrombin-fibrinogen interaction is -24 +/- 3 kcal/mol and the entropy is -55 +/- 11 cal mol-1 deg-1. A chemical compensation effect is present in the binding of fibrinogen and synthetic amide substrates to thrombin, with the delta H and delta G values being linked through a linear relationship. PMID:1445891

  5. Mechanisms of fibrinogen-induced microvascular dysfunction during cardiovascular disease

    PubMed Central

    Lominadze, D.; Dean, W. L.; Tyagi, S. C.; Roberts, A. M.

    2009-01-01

    Fibrinogen (Fg) is a high molecular weight plasma adhesion protein and a biomarker of inflammation. Many cardiovascular and cerebrovascular disorders are accompanied by increased blood content of Fg. Increased levels of Fg result in changes in blood rheological properties such as increases in plasma viscosity, erythrocyte aggregation, platelet thrombogenesis, alterations in vascular reactivity and compromises in endothelial layer integrity. These alterations exacerbate the complications in peripheral blood circulation during cardiovascular diseases such as hypertension, diabetes and stroke. In addition to affecting blood viscosity by altering plasma viscosity and erythrocyte aggregation, growing experimental evidence suggests that Fg alters vascular reactivity and impairs endothelial cell layer integrity by binding to its endothelial cell membrane receptors and activating signalling mechanisms. The purpose of this review is to discuss experimental data, which demonstrate the effects of Fg causing vascular dysfunction and to offer possible mechanisms for these effects, which could exacerbate microcirculatory complications during cardiovascular diseases accompanied by increased Fg content. PMID:19723026

  6. Reduced Transfusion During OLT by POC Coagulation Management and TEG Functional Fibrinogen: A Retrospective Observational Study

    PubMed Central

    De Pietri, Lesley; Ragusa, Francesca; Deleuterio, Annalisa; Begliomini, Bruno; Serra, Valentina

    2016-01-01

    Background Patients undergoing orthotopic liver transplantation are at high risk of bleeding complications. Several Authors have shown that thromboelastography (TEG)-based coagulation management and the administration of fibrinogen concentrate reduce the need for blood transfusion. Methods We conducted a single-center, retrospective cohort observational study (Modena Polyclinic, Italy) on 386 consecutive patients undergoing liver transplantation. We assessed the impact on resource consumption and patient survival after the introduction of a new TEG-based transfusion algorithm, requiring also the introduction of the fibrinogen functional thromboelastography test and a maximum amplitude of functional fibrinogen thromboelastography transfusion cutoff (7 mm) to direct in administering fibrinogen (2012-2014, n = 118) compared with a purely TEG-based algorithm previously used (2005-2011, n = 268). Results After 2012, there was a significant decrease in the use of homologous blood (1502 ± 1376 vs 794 ± 717 mL, P < 0.001), fresh frozen plasma (537 ± 798 vs 98 ± 375 mL, P < 0.001), and platelets (158 ± 280 vs 75 ± 148 mL, P < 0.005), whereas the use of fibrinogen increased (0.1 ± 0.5 vs 1.4 ± 1.8 g, P < 0.001). There were no significant differences in 30-day and 6-month survival between the 2 groups. Conclusions The implementation of a new coagulation management method featuring the addition of the fibrinogen functional thromboelastography test to the TEG test according to an algorithm which provides for the administration of fibrinogen has helped in reducing the need for transfusion in patients undergoing liver transplantation with no impact on their survival. PMID:27500243

  7. Retinoids stimulate fibrinogen production both in vitro (hepatocytes) and in vivo. Induction requires activation of the retinoid X receptor.

    PubMed

    Nicodeme, E; Nicaud, M; Issandou, M

    1995-10-01

    The in vitro effects of retinoids on fibrinogen synthesis were investigated in HepG2 cells and primary human hepatocytes. In vivo effects were studied in the rat. In HepG2 cells, maximal stimulation (twofold) of fibrinogen secretion was obtained when cells were incubated in the presence of 1 mumol/L all-trans retinoic acid (T-RA) for 24 hours. A comparable increase was observed for both de novo fibrinogen synthesis and fibrinogen beta chain mRNA level. In primary cultures of human hepatocytes, treatment with 1 mumol/L T-RA for 72 hours also gave a twofold increase in fibrinogen production. Furthermore, rats treated for 6 days with 100 mg.kg-1.d-1 T-RA presented increased fibrinogen plasma levels (110%). A selective retinoic X receptor (RXR) agonist, 4-[1-3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)-ethenyl]benzoi c acid (3-methyl TTNEB), as well as 9-cis retinoic acid, a natural RXR ligand, mimicked the effects of T-RA on fibrinogen synthesis in vitro at lower concentrations. In contrast, a selective retinoic A receptor alpha (RAR alpha) agonist was a poor activator. The ED50 of the different retinoids on fibrinogen secretion by HepG2 cells was 25 nmol/L for T-RA, 4 nmol/L for 9-cis retinoic acid, 11 nmol/L for the synthetic RXR agonist, and > 500 nmol/L for the RAR alpha agonist. However, incubation of HepG2 cells with RXR agonist together with RAR alpha agonist resulted in a further increase in fibrinogen production. The secretion of two other acute-phase proteins, alpha-antichymotrypsin and caeruloplasmin, was also stimulated by retinoids in HepG2 cells but by a different regulatory mechanism.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7583541

  8. Spatially selective surface platforms for binding fibrinogen prepared by particle lithography with organosilanes

    PubMed Central

    Englade-Franklin, Lauren E.; Saner, ChaMarra K.; Garno, Jayne C.

    2013-01-01

    We introduce an approach based on particle lithography to prepare spatially selective surface platforms of organosilanes that are suitable for nanoscale studies of protein binding. Particle lithography was applied for patterning fibrinogen, a plasma protein that has a major role in the clotting cascade for blood coagulation and wound healing. Surface nanopatterns of mercaptosilanes were designed as sites for the attachment of fibrinogen within a protein-resistant matrix of 2-[methoxy(polyethyleneoxy)propyl] trichlorosilane (PEG-silane). Preparing site-selective surfaces was problematic in our studies, because of the self-reactive properties of PEG-organosilanes. Certain organosilanes presenting hydroxyl head groups will cross react to form mixed surface multi-layers. We developed a clever strategy with particle lithography using masks of silica mesospheres to protect small, discrete regions of the surface from cross reactions. Images acquired with atomic force microscopy (AFM) disclose that fibrinogen attached primarily to the surface areas presenting thiol head groups, which were surrounded by PEG-silane. The activity for binding anti-fibrinogen was further evaluated using ex situ AFM studies, confirming that after immobilization the fibrinogen nanopatterns retained capacity for binding immunoglobulin G. Studies with AFM provide advantages of achieving nanoscale resolution for detecting surface changes during steps of biochemical surface reactions, without requiring chemical modification of proteins or fluorescent labels. PMID:24427541

  9. Fibrinogen-induced perivascular microglial clustering is required for the development of axonal damage in neuroinflammation

    PubMed Central

    Davalos, Dimitrios; Kyu Ryu, Jae; Merlini, Mario; Baeten, Kim M.; Le Moan, Natacha; Petersen, Mark A.; Deerinck, Thomas J.; Smirnoff, Dimitri S.; Bedard, Catherine; Hakozaki, Hiroyuki; Gonias Murray, Sara; Ling, Jennie B.; Lassmann, Hans; Degen, Jay L.; Ellisman, Mark H.; Akassoglou, Katerina

    2012-01-01

    Blood-brain barrier disruption, microglial activation and neurodegeneration are hallmarks of multiple sclerosis. However, the initial triggers that activate innate immune responses and their role in axonal damage remain unknown. Here we show that the blood protein fibrinogen induces rapid microglial responses toward the vasculature and is required for axonal damage in neuroinflammation. Using in vivo two-photon microscopy, we demonstrate that microglia form perivascular clusters before myelin loss or paralysis onset and that, of the plasma proteins, fibrinogen specifically induces rapid and sustained microglial responses in vivo. Fibrinogen leakage correlates with areas of axonal damage and induces reactive oxygen species release in microglia. Blocking fibrin formation with anticoagulant treatment or genetically eliminating the fibrinogen binding motif recognized by the microglial integrin receptor CD11b/CD18 inhibits perivascular microglial clustering and axonal damage. Thus, early and progressive perivascular microglial clustering triggered by fibrinogen leakage upon blood-brain barrier disruption contributes to axonal damage in neuroinflammatory disease. PMID:23187627

  10. Importance of fibrinogen in dilutional coagulopathy after neurosurgical procedures: A descriptive study

    PubMed Central

    Nair, Shalini; Nair, Bijesh Ravindran; Vidyasagar, Ajay; Joseph, Mathew

    2016-01-01

    Background and Aims: The routine management of coagulopathy during surgery involves assessing haemoglobin, prothrombin time (PT), activated partial thromboplastin time (aPTT) and platelets. Correction of these parameters involves administration of blood, fresh frozen plasma and platelet concentrates. The study was aimed at identifying the most common coagulation abnormality during neurosurgical procedures and the treatment of dilutional coagulopathy with blood components. Methods: During 2 years period, all adult patients undergoing neurosurgical procedures who were transfused two or more units of red cells were prospectively evaluated for the presence of a coagulopathy. PT, aPTT, platelet count and fibrinogen levels were estimated before starting a component therapy. Results: After assessing PT, aPTT, platelet count and fibrinogen levels following two or more blood transfusions, thirty patients were found to have at least one abnormal parameter that required administration of a blood product. The most common abnormality was a low fibrinogen level, seen in 26 patients; this was the only abnormality in three patients. No patient was found to have an abnormal PT or aPTT without either the fibrinogen concentration or platelet count or both being low. Conclusion: Low fibrinogen concentration was the most common coagulation abnormality found after blood transfusions for neurosurgical procedures. PMID:27601735

  11. The association between fibrinogen reactivity to mental stress and high-sensitivity cardiac troponin T in healthy adults

    PubMed Central

    Lazzarino, Antonio Ivan; Hamer, Mark; Gaze, David; Collinson, Paul; Rumley, Ann; Lowe, Gordon; Steptoe, Andrew

    2015-01-01

    Summary Background Plasma fibrinogen is considered as a positive mediator between mental stress and cardiovascular disease because it is an acute-phase protein released in response to mental stress and a coagulation factor. However those three factors have never been studied together within a single integrated framework, using cardiac troponin T as a marker of cardiovascular risk. Methods 491 disease-free men and women aged 53–76 were tested for fibrinogen levels before, immediately after, and following recovery from standardized mental stress tasks. We measured plasma cardiac troponin T using a high-sensitivity assay (HS-CTnT) and coronary calcification using electron-beam dual-source computed tomography. Results The average fibrinogen concentration increased by 5.1% (s.d. = 7.3) in response to stress and then tended to return to baseline values. People with higher baseline fibrinogen values had smaller increases (blunted responses) following the stress task (P = 0.001), and people with higher stress responses showed better recovery (P < 0.001). In unadjusted analyses, higher baseline fibrinogen was associated with higher chances of having detectable HS-CTnT (P = 0.072) but, conversely, higher fibrinogen response was associated with lower chances of having detectable HS-CTnT (P = 0.007). The adjustment for clinical, inflammatory, and haemostatic factors, as well as for coronary calcification eliminated the effect of baseline fibrinogen, whereas the negative association between fibrinogen response and HS-CTnT remained robust: the odds of detectable HS-CTnT halved for each 10% increase in fibrinogen concentration due to stress (OR = 0.49, P = 0.007, 95% CI = 0.30–0.82). Conclusions Greater fibrinogen responses to mental stress are associated with lower likelihood of detectable high-sensitivity troponin T plasma concentration. A more dynamic fibrinogen response appears to be advantageous for cardiovascular health. PMID:26010862

  12. A Multi-Ethnic Meta-Analysis of Genome-Wide Association Studies in Over 100,000 Subjects Identifies 23 Fibrinogen-Associated Loci but no Strong Evidence of a Causal Association between Circulating Fibrinogen and Cardiovascular Disease

    PubMed Central

    Sabater-Lleal, Maria; Huang, Jie; Chasman, Daniel; Naitza, Silvia; Dehghan, Abbas; Johnson, Andrew D; Teumer, Alexander; Reiner, Alex P; Folkersen, Lasse; Basu, Saonli; Rudnicka, Alicja R; Trompet, Stella; Mälarstig, Anders; Baumert, Jens; Bis, Joshua C.; Guo, Xiuqing; Hottenga, Jouke J; Shin, So-Youn; Lopez, Lorna M; Lahti, Jari; Tanaka, Toshiko; Yanek, Lisa R; Oudot-Mellakh, Tiphaine; Wilson, James F; Navarro, Pau; Huffman, Jennifer E; Zemunik, Tatijana; Redline, Susan; Mehra, Reena; Pulanic, Drazen; Rudan, Igor; Wright, Alan F; Kolcic, Ivana; Polasek, Ozren; Wild, Sarah H; Campbell, Harry; Curb, J David; Wallace, Robert; Liu, Simin; Eaton, Charles B.; Becker, Diane M.; Becker, Lewis C.; Bandinelli, Stefania; Räikkönen, Katri; Widen, Elisabeth; Palotie, Aarno; Fornage, Myriam; Green, David; Gross, Myron; Davies, Gail; Harris, Sarah E; Liewald, David C; Starr, John M; Williams, Frances M.K.; Grant, P.J.; Spector, Timothy D.; Strawbridge, Rona J; Silveira, Angela; Sennblad, Bengt; Rivadeneira, Fernando; Uitterlinden, Andre G; Franco, Oscar H; Hofman, Albert; van Dongen, Jenny; Willemsen, G; Boomsma, Dorret I; Yao, Jie; Jenny, Nancy Swords; Haritunians, Talin; McKnight, Barbara; Lumley, Thomas; Taylor, Kent D; Rotter, Jerome I; Psaty, Bruce M; Peters, Annette; Gieger, Christian; Illig, Thomas; Grotevendt, Anne; Homuth, Georg; Völzke, Henry; Kocher, Thomas; Goel, Anuj; Franzosi, Maria Grazia; Seedorf, Udo; Clarke, Robert; Steri, Maristella; Tarasov, Kirill V; Sanna, Serena; Schlessinger, David; Stott, David J; Sattar, Naveed; Buckley, Brendan M; Rumley, Ann; Lowe, Gordon D; McArdle, Wendy L; Chen, Ming-Huei; Tofler, Geoffrey H; Song, Jaejoon; Boerwinkle, Eric; Folsom, Aaron R.; Rose, Lynda M.; Franco-Cereceda, Anders; Teichert, Martina; Ikram, M Arfan; Mosley, Thomas H; Bevan, Steve; Dichgans, Martin; Rothwell, Peter M.; Sudlow, Cathie L M; Hopewell, Jemma C.; Chambers, John C.; Saleheen, Danish; Kooner, Jaspal S.; Danesh, John; Nelson, Christopher P; Erdmann, Jeanette; Reilly, Muredach P.; Kathiresan, Sekar; Schunkert, Heribert; Morange, Pierre-Emmanuel; Ferrucci, Luigi; Eriksson, Johan G; Jacobs, David; Deary, Ian J; Soranzo, Nicole; Witteman, Jacqueline CM; de Geus, Eco JC; Tracy, Russell P.; Hayward, Caroline; Koenig, Wolfgang; Cucca, Francesco; Jukema, J Wouter; Eriksson, Per; Seshadri, Sudha; Markus, Hugh S.; Watkins, Hugh; Samani, Nilesh J; Wallaschofski, Henri; Smith, Nicholas L.; Tregouet, David; Ridker, Paul M.; Tang, Weihong; Strachan, David P.; Hamsten, Anders; O’Donnell, Christopher J.

    2013-01-01

    Background Estimates of the heritability of plasma fibrinogen concentration, an established predictor of cardiovascular disease (CVD), range from 34 to 50%. Genetic variants so far identified by genome-wide association (GWA) studies only explain a small proportion (< 2%) of its variation. Methods and Results We conducted a meta-analysis of 28 GWA studies, including more than 90,000 subjects of European ancestry, the first GWA meta-analysis of fibrinogen levels in 7 African Americans studies totaling 8,289 samples, and a GWA study in Hispanic-Americans totaling 1,366 samples. Evaluation for association of SNPs with clinical outcomes included a total of 40,695 cases and 85,582 controls for coronary artery disease (CAD), 4,752 cases and 24,030 controls for stroke, and 3,208 cases and 46,167 controls for venous thromboembolism (VTE). Overall, we identified 24 genome-wide significant (P<5×10−8) independent signals in 23 loci, including 15 novel associations, together accounting for 3.7% of plasma fibrinogen variation. Gene-set enrichment analysis highlighted key roles in fibrinogen regulation for the three structural fibrinogen genes and pathways related to inflammation, adipocytokines and thyrotrophin-releasing hormone signaling. Whereas lead SNPs in a few loci were significantly associated with CAD, the combined effect of all 24 fibrinogen-associated lead SNPs was not significant for CAD, stroke or VTE. Conclusion We identify 23 robustly associated fibrinogen loci, 15 of which are new. Clinical outcome analysis of these loci does not support a causal relationship between circulating levels of fibrinogen and CAD, stroke or VTE. PMID:23969696

  13. Histamine release and fibrinogen adsorption mediate acute inflammatory responses to biomaterial implants in humans

    PubMed Central

    Zdolsek, Johann; Eaton, John W; Tang, Liping

    2007-01-01

    Background Medical implants often fail as a result of so-called foreign body reactions during which inflammatory cells are recruited to implant surfaces. Despite the clinical importance of this phenomenon, the mechanisms involved in these reactions to biomedical implants in humans are not well understood. The results from animal studies suggest that both fibrinogen adsorption to the implant surface and histamine release by local mast cells are involved in biomaterial-mediated acute inflammatory responses. The purpose of this study was to test this hypothesis in humans. Methods Thirteen male medical student volunteers (Caucasian, 21–30 years of age) were employed for this study. To assess the importance of fibrinogen adsorption, six volunteers were implanted with polyethylene teraphthalate disks pre-coated with their own (fibrinogen-containing) plasma or (fibrinogen-free) serum. To evaluate the importance of histamine, seven volunteers were implanted with uncoated disks with or without prior oral administration of histamine receptor antagonists. The acute inflammatory response was estimated 24 hours later by measuring the activities of implant-associated phagocyte-specific enzymes. Results Plasma coated implants accumulated significantly more phagocytes than did serum coated implants and the recruited cells were predominantly macrophage/monocytes. Administration of both H1 and H2 histamine receptor antagonists greatly reduced the recruitment of macrophages/monocytes and neutrophils on implant surfaces. Conclusion In humans – as in rodents – biomaterial-mediated inflammatory responses involve at least two crucial events: histamine-mediated phagocyte recruitment and phagocyte accumulation on implant surfaces engendered by spontaneously adsorbed host fibrinogen. Based on these results, we conclude that reducing fibrinogen:surface interactions should enhance biocompatibility and that administration of histamine receptor antagonists prior to, and shortly after

  14. Nitric oxide releasing material adsorbs more fibrinogen.

    PubMed

    Lantvit, Sarah M; Barrett, Brittany J; Reynolds, Melissa M

    2013-11-01

    One mechanism of the failure of blood-contacting devices is clotting. Nitric oxide (NO) releasing materials are seen as a viable solution to the mediation of surface clotting by preventing platelet activation; however, NO's involvement in preventing clot formation extends beyond controlling platelet function. In this study, we evaluate NO's effect on factor XII (fibrinogen) adsorption and activation, which causes the initiation of the intrinsic arm of the coagulation cascade. This is done by utilizing a model plasticized poly(vinyl) chloride (PVC), N-diazeniumdiolate system and looking at the adsorption of fibrinogen, an important clotting protein, to these surfaces. The materials have been prepared in such a way to eliminate changes in surface properties between the control (plasticized PVC) and composite (NO-releasing) materials. This allows us to isolate NO release and determine the effect on the adsorption of fibrinogen, to the material surface. Surprisingly, it was found that an NO releasing material with a surface flux of 17.4 ± 0.5 × 10(-10) mol NO cm(-2) min(-1) showed a significant increase in the amount of fibrinogen adsorbed to the material surface compared to one with a flux of 13.0 ± 1.6 × 10(-10) mol NO cm(-2) min(-1) and the control (2334 ± 496, 226 ± 99, and 103 ±31% fibrinogen adsorbed of control, respectively). This study suggests that NO's role in controlling clotting is extended beyond platelet activation. PMID:23554300

  15. Stimulation of fibrinogen synthesis in cultured rat hepatocytes by fibrinogen degradation product fragment D.

    PubMed Central

    LaDuca, F M; Tinsley, L A; Dang, C V; Bell, W R

    1989-01-01

    The direct stimulation of fibrinogen biosynthesis by fibrinogen degradation produces (FDPs) was studied in rat hepatocyte cultures. Pure rat FDP fragment D (FDP-D) (Mr 90,000) and FDP fragment E (FDP-E) (Mr 40,000) and mixtures of the two (FDP-DE) were added to rat hepatocytes cultured in serum-free hormonally defined medium. Hydrocortisone (20 microM) significantly increased synthesis of fibrinogen, as determined by incorporation of [35S]methionine. FDP-D and FDP-E did not increase fibrinogen synthesis in the presence of hydrocortisone. However, hepatocytes cultured without hydrocortisone displayed increased fibrinogen synthesis (2.0- to 2.8-fold) with FDP-D (2.6-6.7 microM) but not with FDP-E (5.7 microM). At these FDP concentrations the synthesis of albumin, haptoglobin, and transferrin was not increased. FDP-D-induced fibrinogen synthesis was inhibited (greater than 90%) by actinomycin D and cycloheximide, indicating that the increase in [35S]methionine incorporation was from de novo protein synthesis. The role of FDP-D was further substantiated by showing that FDP-D, but not FDP-E, bound to the hepatocytes. These data indicate that FDP-D, but not FDP-E, directly and specifically stimulates fibrinogen synthesis in rat hepatocytes; this stimulation does not require any additional serum or protein cofactors. Images PMID:2813424

  16. THE CONVERSION OF FIBRINOGEN TO FIBRIN

    PubMed Central

    Shulman, Sidney; Katz, Sidney; Ferry, John D.

    1953-01-01

    1. Fibrin clots prepared in the absence of calcium can be dissolved in solutions of lithium chloride and bromide and sodium bromide and iodide, as well as of guanidine hydrochloride and urea. These salts do not denature fibrinogen under the same conditions of concentration, temperature, and time. Sedimentation experiments on the fibrin solutions show in each case a single sharp peak with a sedimentation constant close to that of fibrinogen. 2. At lower concentrations, these salts inhibit the clotting of fibrinogen by thrombin, but in the case of lithium bromide and sodium iodide, at least, allow an intermediate polymer to accumulate whose sedimentation constant is close to that of the polymer observed in systems inhibited by hexamethylene glycol or urea. PMID:13069679

  17. Clotting of mammalian fibrinogens by papain: a re-examination.

    PubMed

    Doolittle, Russell F

    2014-10-28

    Papain has long been known to cause the gelation of mammalian fibrinogens. It has also been reported that papain-fibrin is insoluble in dispersing solvents like strong urea or sodium bromide solutions, similar to what is observed with thrombin-generated clots in the presence of factor XIIIa and calcium. In those old studies, both the gelation and subsequent clot stabilization were attributed to papain, although the possibility that the second step might be due to contaminating factor XIII in fibrinogen preparations was considered. I have revisited this problem in light of knowledge acquired over the past half-century about thiol proteases like papain, which mostly cleave peptide bonds, and transglutaminases like factor XIIIa that catalyze the formation of ε-lysyl-γ-glutamyl cross-links. Recombinant fibrinogen, inherently free of factor XIII and other plasma proteins, formed a stable gel when treated with papain alone. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the intermolecular cross-linking in papain-fibrin leads to γ-chain dimers, trimers, and tetramers, just as is the case with thrombin-factor XIIIa-stabilized fibrin. Mass spectrometry of bands excised from gels showed that the cross-linked material is quite different from what occurs with factor XIIIa, however. With papain, the cross-linking occurs between γ chains in neighboring protofibrils becoming covalently linked in a "head-to-tail" fashion by a transpeptidation reaction involving the α-amino group of γ-Tyr1 and a papain cleavage site at γ-Gly403 near the carboxy terminus, rather than by the (reciprocal) "tail-to-tail" manner that occurs with factor XIIIa and that depends on cross-links between γ-Lys406 and γ-Gln398. PMID:25283163

  18. Role of fibrinogen in acute ischemic kidney injury.

    PubMed

    Sörensen-Zender, I; Rong, S; Susnik, N; Lange, J; Gueler, F; Degen, J L; Melk, A; Haller, H; Schmitt, R

    2013-09-01

    Renal ischemia-reperfusion (I/R) is associated with activation of the coagulation system and accumulation of blood clotting factors in the kidney. The aim of the present study was to examine the functional impact of fibrinogen on renal inflammation, damage, and repair in the context of I/R injury. In this study, we found that I/R was associated with a significant increase in the renal deposition of circulating fibrinogen. In parallel, I/R stress induced the de novo expression of fibrinogen in tubular epithelial cells, as reflected by RT-PCR, immunofluorescence, and in situ hybridization. In vitro, fibrinogen expression was induced by oncostatin M and hyper-IL-6 in primary tubular epithelial cells, and fibrinogen-containing medium had an inhibitory effect on tubular epithelial cell adhesion and migration. Fibrinogen(+/-) mice showed similar survival as wild-type mice but better preservation in early postischemic renal function. In fibrinogen(-/-) mice, renal function and survival were significantly worse than in fibrinogen(+/-) mice. Renal transplant experiments revealed reduced expression of tubular damage markers and attenuated proinflammatory cytokine expression but increased inflammatory cell infiltrates and transforming growth factor-β expression in fibrinogen(-/-) isografts. These data point to heterogeneous effects of fibrinogen in renal I/R injury. While a complete lack of fibrinogen may be detrimental, partial reduction of fibrinogen in heterozygous mice can improve renal function and overall outcome. PMID:23804451

  19. Sensitive Immunoassays of Nitrated Fibrinogen in Human Biofluids

    SciTech Connect

    Tang, Zhiwen; Wu, Hong; Du, Dan; Wang, Jun; Wang, Hua; Qian, Weijun; Bigelow, Diana J.; Pounds, Joel G.; Smith, Richard D.; Lin, Yuehe

    2010-05-05

    Three new sandwich immunoassays for detection of nitrated biomarker have been established with potential applications in biomedical studies and clinical practice. In this study, nitrated human fibrinogen, a potential oxidative stress biomarker for several pathologies, was chosen as the target. To improve the sensitivity and overcome the interference caused by the complexity of human biofluids, we developed three sandwich strategies using various combinations of primary antibody and secondary antibody. All three strategies demonstrated high sensitivity and selectivity towards nitrated forms of fibrinogen in buffer, but their performances were dramatically reduced when tested with human plasma and serum samples. Systematically optimizations were carried out to investigate the effects of numerous factors, including sampling, coating, blocking, and immunoreactions. Our final optimization results indicate that two of these strategies retain sufficient sensitivity and selectivity for use as assays in human physiological samples. Specifically, detection limits reached the pM level and the linear response ranges were up to nM level with a correlation coefficient > 0.99. To our best knowledge, this is the first example of using an electrochemical immunoassay for a nitrated biomarker in a physiological fluid. This novel approach provides a rapid, sensitive, selective, cost efficient and robust bioassay for detection of oxidative stress in pathology and for clinical applications. Moreover, the sandwich strategies developed in this paper can be readily used to establish effective methods targeting other nitration biomarkers.

  20. The influence of glucocorticoid on the fibrinogen messenger RNA content of rat liver in vivo and in hepatocyte suspension culture.

    PubMed Central

    Princen, H M; Moshage, H J; de Haard, H J; van Gemert, P J; Yap, S H

    1984-01-01

    The plasma concentration of fibrinogen, one of the major acute-phase proteins produced by the liver, increases during the acute-phase response as a result of enhanced synthesis in liver. Since adrenal-cortical hormones have been thought to have a key role in the regulation of the fibrinogen synthesis, fibrinogen-polypeptide mRNA sequences were determined in the present study, by using a specific complementary-DNA probe, in RNA fractions obtained from rat hepatocytes exposed to glucocorticoids in vitro (hepatocyte suspension cultures) and in vivo. Maximal induction of the fibrinogen-polypeptide mRNA (to 400% of the control value) was found in vitro at 0.1 microM-dexamethasone after 9 h of incubation. The same magnitude of induction was obtained with 20 microM-cortisol or 60 microM-corticosterone. In contrast with the findings in vitro, no induction of the fibrinogen-polypeptide mRNA was observed in the liver at various times after injection of different doses of glucocorticoids into rats. These results suggest that more complex regulatory mechanisms are involved and that glucocorticoids are not the sole regulatory factors in vivo in the enhanced synthesis of fibrinogen during the acute-phase response. PMID:6547834

  1. Influence of fibrinogen and haematocrit on erythrocyte sedimentation kinetics.

    PubMed

    Holley, L; Woodland, N; Hung, W T; Cordatos, K; Reuben, A

    1999-01-01

    This study investigates the influence of haematocrit, fibrinogen concentration and fibrinogen availability (amount of fibrinogen per red blood cell) on erythrocyte sedimentation. The Westergren technique was applied to blood samples from 36 subjects and to their blood manipulated to haematocrits of 10, 20, 30 and 40%. Readings were taken every 10 minutes for 300 minutes. Previous studies indicate that erythrocyte sedimentation occurs in three phases. In this study, we show that haematocrit has little influence on either the rate of fall of particles in the first phase (m1) or the duration of the first phase. This is also true for fibrinogen availability and for fibrinogen concentration at low haematocrits. At high haematocrits m1 increases with fibrinogen concentration. The rate of fall of rouleaux during phase 2 (m2) and ESR60 both decrease exponentially with haematocrit and increase linearly with fibrinogen concentration. While m2 is more closely correlated to fibrinogen availability than to fibrinogen concentration or to haematocrit, this is not the case for ESR60. Thus haematocrit, fibrinogen concentration and fibrinogen availability are more important to the velocity of sedimentation in the second phase than to the sedimenting velocity during phase 1 or to the duration of phase 1. PMID:10690265

  2. Effect of stress hormones on the expression of fibrinogen-binding receptors in platelets.

    PubMed

    Lam, Nicole Y-L; Rainer, Timothy H; Ng, Margaret H-L; Leung, Yonna; Cocks, Robert A

    2002-12-01

    Acute coagulopathy is a common clinical complication after trauma, and contributes to posttraumatic multiple organ failure. The phenomenon may be due to the effect of stress hormones on platelet adhesion molecule expression after trauma. Catecholamine levels correlate with injury severity scores and changes of L-selectin expression on leucocytes, whilst adrenaline (ADR) (epinephrine) alone also activates platelets. This study thus investigates the effects of ADR and noradrenaline (NOR) (norepinephrine) on platelets, at doses similar to those found in the plasma of normal and trauma subjects. Blood was taken from 19 healthy subjects and placed in tubes containing sodium citrate. Anti-platelet-bound fibrinogen monoclonal antibody was used to identify the activated platelets while anti-CD41 was used to identify platelets with and without activation. Five increasing concentrations of ADR and NOR (1, 3, 5, 10, 30 nmol/l) as well as one negative control (0.9% normal saline) and one positive control (10 micromol/l adenosine diphosphate/ADP) were prepared for the stimulation. A whole blood protocol was used in order to minimize any activation artefacts, which might be created by centrifugation. The percentage of platelets expressing fibrinogen receptors increased significantly with ADR and NOR even at the lowest dose (1 nmol/l) and continued to increase in a dose-dependent manner. Although the effect of ADR was greater than NOR in stimulating platelets to express fibrinogen receptors, the average number of fibrinogen receptors on each platelet was constant. ADR and NOR activated platelets to express fibrinogen receptors at doses that are similar to those found in the plasma of trauma patients. PMID:12458065

  3. Interaction of fibrinogen and albumin with titanium dioxide nanoparticles of different crystalline phases

    NASA Astrophysics Data System (ADS)

    Marucco, Arianna; Fenoglio, Ivana; Turci, Francesco; Fubini, Bice

    2013-04-01

    TiO2 nanoparticles (NPs) are contained in different kinds of industrial products including paints, self-cleaning glasses, sunscreens. TiO2 is also employed in photocatalysis and it has been proposed for waste water treatment. Micrometric TiO2 is generally considered a safe material, while there is concern on the possible health effects of nanometric titania. Due to their small size NPs may migrate within the human body possibly entering in the blood stream. Therefore studies on the interaction of NPs with plasma proteins are needed. In fact, the interaction with proteins is believed to ultimately influences the NPs biological fate. Fibrinogen and albumin are two of the most abundant plasma proteins. They are involved in several important physiological functions. Furthermore, fibrinogen is known to trigger platelet adhesion and inflammation. For these reasons the study of the interaction between these protein and nanoparticles is an important step toward the understanding of the behavior of NPs in the body. In this study we investigated the interaction of albumin and fibrinogen with TiO2 nanoparticles of different crystal phases (rutile and anatase) using an integrated set of techniques. The amount of adsorbed fibrinogen and albumin for each TiO2 surface was investigated by using the bicinchoninic acid assay (BCA). The variation of the surface charge of the NP-protein conjugates respect to the naked NPs was used to indirectly estimate both surface coverage and reversibility of the adsorption upon dilution. Surface charge was monitored by measuring the ζ potential with a conventional electrophoretic light scattering (ELS) system. The extent of protein deformation was evaluated by Raman Spectroscopy. We found that both proteins adsorb irreversibly against electrostatic repulsion, likely undergoing conformational changes or selective orientation upon adsorption. The size of primary particles and the particles aggregation rather than the crystal phase modulate the

  4. Single-molecule surface studies of fibrinogen and DNA on semiconductors

    NASA Astrophysics Data System (ADS)

    Kong, Xianhua

    Understanding of protein adsorption onto non-biological substrates is of fundamental interest in science, but also has great potential technological applications in medical devices and biosensors. This study explores the non-specific interaction, at the single molecule level, of a blood protein and DNA with semiconductor surfaces through the use of a custom built, non rastering electron emission microscope and a scanning probe microscope. The specifics and history of electron emission are described as well as the equipment used in this study. The protein examined in this study is human plasma fibrinogen, which plays an important role in haemostatis and thrombosis, and deoxyribonucleic acid (DNA) is also studied. A novel technique for determining the photothreshold of biomolecules on single molecule level is developed and applied to fibrinogen molecules adsorbed on oxidized silicon surfaces, using photo-electron emission microscopy (PEEM). Three theoretical models are employed and compared to analyze the experimental photothreshold data. The non-specific adsorption of human plasma fibrinogen on oxidized p- and n- type silicon (100) surfaces is investigated to characterize both hydrophobic interactions and electrostatic forces. The experimental results indicate that hydrophobic interactions are one of the driving forces for protein adsorption and the electrostatic interactions also play a role in the height of the fibrinogen molecules adsorbed on the surface. PEEM images establish a photo threshold of 5.0 +/- 0.2 eV for fibrinogen on both n-type and p-type Si (100) surfaces. We suggest that the photothreshold results from surface state associated Fermi level (EF) pinning and there exists negative charge transfer from the adsorbed fibrinogen onto the p-type silicon substrates, while on n-type silicon substrates negative charge is transferred in the opposite direction. The adsorption of deoxyribonucleic acid (DNA) on mica and silicon is studied in liquid and ambient

  5. Immunological Identification of Fibrinogen in Dual-Component Protein Films by AFM Imaging

    PubMed Central

    Soman, Pranav; Rice, Zachary; Siedlecki, Christopher A.

    2009-01-01

    The success of long-term blood-contacting implanted devices is largely dependent upon the interaction of the blood components with the device biomaterial surface. The ability to study these interactions has been hindered by a lack of methods to measure single-molecule interactions in complex multi-protein environments similar to the environment found in-vivo. In this paper, we demonstrate the use of atomic force microscopy (AFM) in conjunction with gold nanolabels to detect the protein fibrinogen under aqueous conditions without the topographical clues usually necessary for high resolution visualization. BSA was patterned onto both muscovite mica and plasma-treated polydimethylsiloxane (PDMS) substrates and these test substrates were subsequently backfilled with fibrinogen to yield a featureless protein layer. The fibrinogen in this dual protein layer was detected using high resolution AFM imaging following infusion of anti-fibrinogen conjugated with nanogold particles. This AFM immuno-detection technique will potentially be applicable to complex multi-component protein films adsorbed on clinically-relevant polymers used in medical devices. PMID:18294855

  6. Fibrinogen is degraded and internalized during incubation with neutrophils, and fibrinogen products localize to electron lucent vesicles.

    PubMed Central

    Kirsch, Richard; Jaffer, Mohamed A; Woodburne, Vivienne E; Sewell, Trevor; Kelly, Sharon L; Kirsch, Ralph E; Shephard, Enid G

    2002-01-01

    A biologically relevant relationship exists between neutrophils and coagulation processes. Several studies have focused on the ability of neutrophil proteases (both intracellular and membrane-associated) to degrade fibrinogen. The present study investigates the events following the interaction of activated neutrophils with soluble fibrinogen. During incubation of PMA-stimulated neutrophils with fibrinogen at 37 degrees C, fibrinogenolysis occurred, and degraded fibrinogen became associated with the neutrophil. Immunoelectron microscopy identified these fibrinogen products to be located within electron lucent vesicles, and not on the surface of the cell, suggesting that they are internalized. Although a specific interaction between fibrinogen and the neutrophil membrane might assist uptake, in the presence of physiological concentrations of fibrinogen, internalization occurred largely via a non-specific pinocytic process. Studies at low temperature revealed that both intact and degraded forms of fibrinogen can associate with neutrophils. The fibrinogen products detected intracellularly in experiments performed at 37 degrees C might represent uptake of degraded as well as intact forms of fibrinogen, the latter being rapidly degraded intracellularly. This route of fibrinogenolysis contributes minimally to the overall extent of the degradation process, the majority occurring extracellularly. Neutrophils thus possess a proteolytic mechanism for preventing accumulation of surface ligand, perhaps allowing them to evade the immunomodulatory effects of such ligands during inflammation. PMID:12023883

  7. Cleavage of fibrinogen by the human neutrophil neutral peptide-generating protease.

    PubMed Central

    Wintroub, B U; Coblyn, J S; Kaempfer, C E; Austen, K F

    1980-01-01

    The human neutrophil peptide-generating protease, which generates a low molecular weight vasoactive peptide from a plasma protein substrate, is directly fibrinolytic and cleaves human fibrinogen in a manner distinct from plasmin. Fibrinogen was reduced from 340,000 Mr to derivatives of 270,000-325,000 Mr during interaction with the protease at enzyme-to-substrate ratios of 0.3 or 1.0 microgram/1.0 mg. The 310,000-325,000 Mr cleavage fragments exhibited prolonged thrombin-induced clotting activity but were able to be coagulated, whereas the 270,000-290,000 Mr fragments were not able to be coagulated. Anticoagulants were not generated at either enzyme dose. As analyzed by sodium dodecyl sulfate/polyacrylamide gel electrophoresis in 4-30% gradient gels and 10% gels stained for protein and carbohydrate, the diminution to 310,000-325,000 Mr and the prolongation of thrombin-induced clotting time resulted from cleavage of the fibrinogen A alpha chain. The further decrease in size to 270,000-290,000 Mr was associated with B beta-chain and gamma-chain cleavage and an inability to form gamma-gamma dimers. The neutral peptide-generating protease, a distinct human neutrophil neutral protease with fibrinolytic and fibrinogenolytic activities comparable to those of plasmin on a weight basis, cleaves fibrinogen in a manner that is distinct from the action of plasmin, leukocyte elastase, and leukocyte granule extracts. It may be that the concerted action of this neutrophil protease to generate a vasoactive peptide and to digest fibrinogen and fibrin facilitates neutrophil movement through vascular and extravascular sites. Images PMID:7001479

  8. Regulation of fibrinogen synthesis by plasmin-derived fragments of fibrinogen and fibrin: an indirect feedback pathway.

    PubMed Central

    Ritchie, D G; Levy, B A; Adams, M A; Fuller, G M

    1982-01-01

    The effect of plasmin-derived fibrinogen fragments on the biosynthesis of fibrinogen was investigated in cultured monolayers of rat hepatocytes. Incubating the cells with several concentrations of either fibrinogen or fibrin fragment D or E had no effect on the synthesis and secretion of fibrinogen by these cells. However, if the fragments were incubated with isolated peripheral blood leukocytes, they caused these cells to secrete a factor that when added to the hepatocytes caused an increase in fibrinogen synthesis 4- to 6-fold over controls. Moreover, the hepatocyte-stimulating factor also affected the production of several other proteins produced by the hepatocyte. These results demonstrate that both fragments D and E can stimulate hepatic fibrinogen synthesis via an indirect leukocyte-mediated pathway. Images PMID:6461860

  9. Post-translational oxidative modification of fibrinogen is associated with coagulopathy after traumatic injury.

    PubMed

    White, Nathan J; Wang, Yi; Fu, Xiaoyun; Cardenas, Jessica C; Martin, Erika J; Brophy, Donald F; Wade, Charles E; Wang, Xu; St John, Alexander E; Lim, Esther B; Stern, Susan A; Ward, Kevin R; López, José A; Chung, Dominic

    2016-07-01

    Victims of trauma often develop impaired blood clot formation (coagulopathy) that contributes to bleeding and mortality. Fibrin polymerization is one critical component of clot formation that can be impacted by post-translational oxidative modifications of fibrinogen after exposure to oxidants. In vitro evidence suggests that Aα-C domain methionine sulfoxide formation, in particular, can induce conformational changes that prevent lateral aggregation of fibrin protofibrils during polymerization. We used mass spectrometry of plasma from trauma patients to find that fibrinogen Aα-C domain methionine sulfoxide content was selectively-increased in patients with coagulopathy vs. those without coagulopathy. This evidence supports a novel linkage between oxidative stress, coagulopathy, and bleeding after injury. PMID:27105953

  10. 21 CFR 864.7340 - Fibrinogen determination system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Fibrinogen determination system. 864.7340 Section 864.7340 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7340 Fibrinogen determination system. (a) Identification....

  11. 21 CFR 864.7340 - Fibrinogen determination system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fibrinogen determination system. 864.7340 Section 864.7340 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7340 Fibrinogen determination system. (a) Identification....

  12. Fibrinogen adsorption onto 316L stainless steel, Nitinol and titanium

    NASA Astrophysics Data System (ADS)

    Bai, Zhijun; Filiaggi, M. J.; Dahn, J. R.

    2009-03-01

    Fibrinogen adsorption onto mechanically polished biomedical grade 316L stainless steel (316LSS), nickel titanium alloy (Nitinol) and commercially pure titanium (CpTi) surfaces were studied by measurements of adsorption isotherms and adsorption kinetics using an ex-situ wavelength dispersive spectroscopy technique (WDS). Surface composition, roughness and wettability of these materials were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and water contact angle (WCA) measurements. Adsorption isotherm results showed that surface protein concentration on these materials increased with increasing concentration of fibrinogen in phosphate buffer solution. The fibrinogen adsorption isotherms were modeled by both the monolayer Langmuir isotherm and the multilayer Brunauer-Emmett-Teller (BET) isotherm. The results strongly suggest that fibrinogen forms multilayer structures on these materials when the concentration in solution is high. Complementary measurements on the absorbed fibrinogen films by spectroscopic ellipsometry (SE) support this view.

  13. Monitoring the effects of fibrinogen concentration on blood coagulation using quartz crystal microbalance (QCM) and its comparison with thromboelastography

    NASA Astrophysics Data System (ADS)

    Lakshmanan, Ramji S.; Efremov, Vitaly; Cullen, Sinéad; Byrne, Barry; Killard, Anthony J.

    2013-05-01

    Fibrinogen has been identified as a major risk factor in cardiovascular disorders. Fibrinogen (340 kDa) is a soluble dimeric glycoprotein found in plasma and is a major component of the coagulation cascade. It has been identified as a major risk factor in cardiovascular disorders. The time taken for its conversion to fibrin is usually used as an "endpoint" in most clot-based assays, without any information on dynamic changes in physical properties or kinetics of a forming clot. A global coagulation profile as measured by Thromboelastography® (TEG®) provides information on both the time and kinetics of changes in physical property of the forming clot. In this work, Quartz crystal microbalance (QCM), which is a piezoelectric resonator has been used to study coagulation of plasma and compared with TEG. The changes in resonant frequency (Δf) and half width at half maximum (HWHM or ΔΓ) were used to evaluate effect of fibrinogen concentration. It has been shown that TEG is less sensitive to low concentrations of fibrinogen and dilution while QCM is able to monitor clot formation in both the circumstances.

  14. Protein adsorption on low temperature isotropic carbon. III. Isotherms, competitivity, desorption and exchange of human albumin and fibrinogen.

    PubMed

    Feng, L; Andrade, J D

    1994-04-01

    In this paper we consider the adsorption of albumin and fibrinogen on low temperature isotropic carbon (LTIC). A subsequent paper considers the adsorption of other plasma proteins [Feng L, Andrade JD, Colloids and Surfaces (in press)]. Carbon fragments and silica plates were used as adsorbents. Adsorption was carried out by incubating the adsorbents in solutions of 125I-labelled and unlabelled proteins (single component system), or with buffer-diluted human plasma (multicomponent system). Adsorbed proteins then underwent displacement by buffer, by single protein solutions or by dilute plasma. Results show that the LTIC substrate adsorbs a large amount of proteins before saturation, which may be due to multilayer adsorption. LTIC also irreversibly holds adsorbed proteins against the exchange agents used; little adsorbed proteins can be displaced, even after a very short adsorption time. There is no preferential adsorption for either albumin or fibrinogen on LTIC from their binary solutions, suggesting that both proteins have high affinities for the surface. Such strong interactions between LTIC and proteins are not attributed to electrostatic interactions. On the other hand, protein adsorption on the silica surface is selective and reversible, with a much higher affinity for fibrinogen than albumin and an even higher affinity for some other plasma proteins. The paper also discusses the effect of sequential protein addition to a solution on the surface concentration and suppression of adsorption of both proteins in the presence of other plasma proteins. A very important conclusion is that the LTIC surface is very active towards proteins adsorption. PMID:8061122

  15. A meta-analysis of 120 246 individuals identifies 18 new loci for fibrinogen concentration.

    PubMed

    de Vries, Paul S; Chasman, Daniel I; Sabater-Lleal, Maria; Chen, Ming-Huei; Huffman, Jennifer E; Steri, Maristella; Tang, Weihong; Teumer, Alexander; Marioni, Riccardo E; Grossmann, Vera; Hottenga, Jouke J; Trompet, Stella; Müller-Nurasyid, Martina; Zhao, Jing Hua; Brody, Jennifer A; Kleber, Marcus E; Guo, Xiuqing; Wang, Jie Jin; Auer, Paul L; Attia, John R; Yanek, Lisa R; Ahluwalia, Tarunveer S; Lahti, Jari; Venturini, Cristina; Tanaka, Toshiko; Bielak, Lawrence F; Joshi, Peter K; Rocanin-Arjo, Ares; Kolcic, Ivana; Navarro, Pau; Rose, Lynda M; Oldmeadow, Christopher; Riess, Helene; Mazur, Johanna; Basu, Saonli; Goel, Anuj; Yang, Qiong; Ghanbari, Mohsen; Willemsen, Gonneke; Rumley, Ann; Fiorillo, Edoardo; de Craen, Anton J M; Grotevendt, Anne; Scott, Robert; Taylor, Kent D; Delgado, Graciela E; Yao, Jie; Kifley, Annette; Kooperberg, Charles; Qayyum, Rehan; Lopez, Lorna M; Berentzen, Tina L; Räikkönen, Katri; Mangino, Massimo; Bandinelli, Stefania; Peyser, Patricia A; Wild, Sarah; Trégouët, David-Alexandre; Wright, Alan F; Marten, Jonathan; Zemunik, Tatijana; Morrison, Alanna C; Sennblad, Bengt; Tofler, Geoffrey; de Maat, Moniek P M; de Geus, Eco J C; Lowe, Gordon D; Zoledziewska, Magdalena; Sattar, Naveed; Binder, Harald; Völker, Uwe; Waldenberger, Melanie; Khaw, Kay-Tee; Mcknight, Barbara; Huang, Jie; Jenny, Nancy S; Holliday, Elizabeth G; Qi, Lihong; Mcevoy, Mark G; Becker, Diane M; Starr, John M; Sarin, Antti-Pekka; Hysi, Pirro G; Hernandez, Dena G; Jhun, Min A; Campbell, Harry; Hamsten, Anders; Rivadeneira, Fernando; Mcardle, Wendy L; Slagboom, P Eline; Zeller, Tanja; Koenig, Wolfgang; Psaty, Bruce M; Haritunians, Talin; Liu, Jingmin; Palotie, Aarno; Uitterlinden, André G; Stott, David J; Hofman, Albert; Franco, Oscar H; Polasek, Ozren; Rudan, Igor; Morange, Pierre-Emmanuel; Wilson, James F; Kardia, Sharon L R; Ferrucci, Luigi; Spector, Tim D; Eriksson, Johan G; Hansen, Torben; Deary, Ian J; Becker, Lewis C; Scott, Rodney J; Mitchell, Paul; März, Winfried; Wareham, Nick J; Peters, Annette; Greinacher, Andreas; Wild, Philipp S; Jukema, J Wouter; Boomsma, Dorret I; Hayward, Caroline; Cucca, Francesco; Tracy, Russell; Watkins, Hugh; Reiner, Alex P; Folsom, Aaron R; Ridker, Paul M; O'Donnell, Christopher J; Smith, Nicholas L; Strachan, David P; Dehghan, Abbas

    2016-01-15

    Genome-wide association studies have previously identified 23 genetic loci associated with circulating fibrinogen concentration. These studies used HapMap imputation and did not examine the X-chromosome. 1000 Genomes imputation provides better coverage of uncommon variants, and includes indels. We conducted a genome-wide association analysis of 34 studies imputed to the 1000 Genomes Project reference panel and including ∼120 000 participants of European ancestry (95 806 participants with data on the X-chromosome). Approximately 10.7 million single-nucleotide polymorphisms and 1.2 million indels were examined. We identified 41 genome-wide significant fibrinogen loci; of which, 18 were newly identified. There were no genome-wide significant signals on the X-chromosome. The lead variants of five significant loci were indels. We further identified six additional independent signals, including three rare variants, at two previously characterized loci: FGB and IRF1. Together the 41 loci explain 3% of the variance in plasma fibrinogen concentration. PMID:26561523

  16. Can the Viscoelastic Parameter α-Angle Distinguish Fibrinogen from Platelet Deficiency and Guide Fibrinogen Supplementation?

    PubMed

    Solomon, Cristina; Schöchl, Herbert; Ranucci, Marco; Schlimp, Christoph J

    2015-08-01

    Viscoelastic tests such as thrombelastography (TEG, Haemoscope Inc., Niles, IL) and thromboelastometry (ROTEM, Tem International GmbH, Munich, Germany), performed in whole blood, are increasingly used at the point-of-care to characterize coagulopathic states and guide hemostatic therapy. An algorithm, based on a mono-analysis (kaolin-activated assay) approach, was proposed in the TEG patent (issued in 2004) where the α-angle and the maximum amplitude parameters are used to guide fibrinogen supplementation and platelet administration, respectively. Although multiple assays for both the TEG and ROTEM devices are now available, algorithms based on TEG mono-analysis are still used in many institutions. In light of more recent findings, we discuss here the limitations and inaccuracies of the mono-analysis approach. Research shows that both α-angle and maximum amplitude parameters reflect the combined contribution of fibrinogen and platelets to clot strength. Therefore, although TEG mono-analysis is useful for identifying a coagulopathic state, it cannot be used to discriminate between fibrin/fibrinogen and/or platelet deficits, respectively. Conversely, the use of viscoelastic methods where 2 assays can be run simultaneously, one with platelet inhibitors and one without, can effectively allow for the identification of specific coagulopathic states, such as insufficient fibrin formation or an insufficient contribution of platelets to clot strength. Such information is critical for making the appropriate choice of hemostatic therapy. PMID:26197367

  17. Thromboembolic events in patients with severe inherited fibrinogen deficiency.

    PubMed

    Rottenstreich, Amihai; Lask, Avigal; Schliamser, Lilliana; Zivelin, Ariella; Seligsohn, Uri; Kalish, Yosef

    2016-08-01

    Inherited afibrinogenemia and hypofibrinogenemia are rare bleeding disorders characterized by markedly reduced levels of fibrinogen in blood. Thrombotic complications in these disorders have been rarely described. We performed a multicenter retrospective study and reviewed the occurrence of thrombotic complications among patients with inherited fibrinogen deficiency. Cases were identified during a review of medical records of all patients with inherited fibrinogen deficiency followed at three different university hospitals in Israel. Nine patients were included in this study: five were afibrinogenemic and four hypofibrinogenemic. There were seven thrombotic events, mostly venous, that occurred in four out of nine patients (44 %). All thrombotic events occurred in afibrinogenemic patients. Mean age at the time of thrombosis was 45 (range 28-61) years. Thrombophilic evaluation performed was negative in all cases. At the time of thrombosis in five out of seven (71.4 %) events, fibrinogen replacement therapy was concurrently given. Therapeutic approach was different among patients ranging from supportive therapy alone, antiplatelet agents and anticoagulant therapy with the concurrent administration of fibrinogen replacement therapy. This study discloses a high rate of thrombosis in patients with afibrinogenemia. Events were both venous and arterial and may be recurrent. Management is highly problematic due to the precarious balance between bleeding and thrombotic risk in these patients. Fibrinogen replacement therapy should be cautiously used in these patients as most thrombotic events followed the administration of fibrinogen replacement therapy. Larger cohorts are warranted to better characterize the best management strategy in these paradoxical events. PMID:26712130

  18. Higher Fibrinogen Level is Independently Linked with the Presence and Severity of New-Onset Coronary Atherosclerosis among Han Chinese Population

    PubMed Central

    Zhang, Yan; Zhu, Cheng-Gang; Guo, Yuan-Lin; Xu, Rui-Xia; Li, Sha; Dong, Qian; Li, Jian-Jun

    2014-01-01

    Background Fibrinogen is a coagulation/inflammatory biomarker strongly associated with atherogenesis. However, no data is currently available regarding the association of fibrinogen level with the presence and severity of new-onset coronary atherosclerosis assessed by Gensini score (GS), particularly in Han Chinese with a large sample size. Methods and Results We studied 2288 consecutive, new-onset subjects undergoing coronary angiography with angina-like chest pain. Clinical and laboratory data were collected. Coronary stenotic lesions were considered to be the incidence of coronary atherosclerosis. The severity of coronary stenosis was determined by the GS system. Data indicated that patients with high GS had significantly elevated fibrinogen level (p<0.001). The prevalence and severity of coronary atherosclerosis were dramatically increased according to fibrinogen tertiles. Spearman correlation analysis revealed a positive association between fibrinogen level and GS (r = 0.138, p<0.001). Multivariate logistic regression analysis demonstrated that plasma fibrinogen level was independently associated with high GS (OR = 1.275, 95% CI 1.082–1.502, p = 0.004) after adjusting for potential confounders. Moreover, fibrinogen level was also independently related to the presence of coronary atherosclerosis (fibrinogen tertile 2: OR = 1.192, 95% CI 0.889–1.598, p = 0.241; tertile 3: OR = 2.003, 95% CI 1.383–2.903, p <0.001) and high GS (fibrinogen tertile 2: OR = 1.079, 95% CI 0.833–1.397, p = 0.565; tertile 3: OR = 1.524, 95% CI 1.155–2.011, p = 0.003) in a dose-dependent manner. Receiver-operating characteristic curve analysis showed that the best fibrinogen cut-off value for predicting the severity of coronary stenosis was 3.21 g/L. Conclusions Higher fibrinogen level is independently linked with the presence and severity of new-onset coronary atherosclerosis in Han Chinese population. PMID:25426943

  19. The FIB-PPH trial: fibrinogen concentrate as initial treatment for postpartum haemorrhage: study protocol for a randomised controlled trial

    PubMed Central

    2012-01-01

    Background Postpartum haemorrhage (PPH) remains a leading cause of maternal mortality worldwide. In Denmark 2% of parturients receive blood transfusion. During the course of bleeding fibrinogen (coagulation factor I) may be depleted and fall to critically low levels, impairing haemostasis and thus worsening the ongoing bleeding. A plasma level of fibrinogen below 2 g/L in the early phase of postpartum haemorrhage is associated with subsequent development of severe haemorrhage. Use of fibrinogen concentrate allows high-dose substitution without the need for blood type crossmatch. So far no publications of randomised controlled trials involving acutely bleeding patients in the obstetrical setting have been published. This trial aims to investigate if early treatment with fibrinogen concentrate reduces the need for blood transfusion in women suffering severe PPH. Methods/Design In this randomised placebo-controlled double-blind multicentre trial, parturients with primary PPH are eligible following vaginal delivery in case of: manual removal of placenta (blood loss ≥ 500 ml) or manual exploration of the uterus after the birth of placenta (blood loss ≥ 1000 ml). Caesarean sections are also eligible in case of perioperative blood loss ≥ 1000 ml. The exclusion criteria are known inherited haemostatic deficiencies, prepartum treatment with antithrombotics, pre-pregnancy weight <45 kg or refusal to receive blood transfusion. Following informed consent, patients are randomly allocated to either early treatment with 2 g fibrinogen concentrate or 100 ml isotonic saline (placebo). Haemostatic monitoring with standard laboratory coagulation tests and thromboelastography (TEG, functional fibrinogen and Rapid TEG) is performed during the initial 24 hours. Primary outcome is the need for blood transfusion. To investigate a 33% reduction in the need for blood transfusion, a total of 245 patients will be included. Four university-affiliated public

  20. Homocysteine influences blood clot properties alone and in combination with total fibrinogen but not with fibrinogen γ' in Africans.

    PubMed

    Nienaber-Rousseau, Cornelie; de Lange, Zelda; Pieters, Marlien

    2015-06-01

    Simultaneously increased fibrinogen and homocysteine (Hcy) in blood are believed to elevate the risk of cardiovascular disease mortality. However, the pathophysiological mechanisms involved are unknown. We sought to determine whether Hcy or its genetic determinants influence blood clot properties alone or in combination with fibrinogen. In addition, we investigated, for the first time, the gamma prime (γ') isoform of fibrinogen with Hcy in relation to clot architecture and lysis. Single-nucleotide polymorphisms, Hcy and hemostatic variables, including clot lysis, determined with a global fibrinolytic assay [giving lag time, slope, maximum absorbance and clot lysis time (CLT)], were measured in 1867 healthy black South Africans and cross-sectionally analyzed. Increasing Hcy did not affect fiber cross-sectional area (maximum absorbance). However, it decreased the time needed to initiate the coagulation cascade and for fibrin fibers to grow (lag time), it increased the tempo of lateral aggregation (slope) and reduced CLT. None of the single-nucleotide polymorphisms measured had effects on clot properties. Combined effects were observed between Hcy and total fibrinogen in predicting CLT. Fibrinogen γ', which affected markers of the fibrinolytic assay, did not have conjoint effects with Hcy. We believe that there is value in recognizing the combined effects of Hcy and fibrinogen, but not its γ' isoform in relation to clot structure and lysis. The enhanced fibrinolysis rate observed in patients with low fibrinogen and high Hcy may have adverse consequences for health if it disturbs hemostasis and results in a bleeding tendency. PMID:25688462

  1. The S. aureus polysaccharide capsule and Efb-dependent fibrinogen shield act in concert to protect against phagocytosis

    PubMed Central

    Kuipers, Annemarie; Stapels, Daphne A. C.; Weerwind, Lleroy T.; Ko, Ya-Ping; Ruyken, Maartje; Lee, Jean C.; van Kessel, Kok P.M.; Rooijakkers, Suzan H. M.

    2016-01-01

    Staphylococcus aureus has developed many mechanisms to escape from human immune responses. In order to resist phagocytic clearance, S. aureus expresses a polysaccharide capsule, which effectively masks the bacterial surface and surface-associated proteins, such as opsonins, from recognition by phagocytic cells. Additionally, secretion of the Extracellular fibrinogen binding protein (Efb) potently blocks phagocytic uptake of the pathogen. Efb creates a fibrinogen shield surrounding the bacteria by simultaneously binding complement C3b and fibrinogen at the bacterial surface. By means of neutrophil phagocytosis assays with fluorescently labeled encapsulated serotype 5 (CP5) and serotype 8 (CP8) strains we now compare the immune-modulating function of these shielding mechanisms. Our data indicate that, in highly encapsulated S. aureus strains, the polysaccharide capsule is able to prevent phagocytic uptake at plasma concentrations <10%, but loses its protective ability at higher concentrations of plasma. Interestingly, Efb shows a strong inhibitory effect on both capsule-negative as well as encapsulated strains at all tested plasma concentrations. Furthermore our results suggest that both shielding mechanisms can exist simultaneously and collaborate to provide optimal protection against phagocytosis at a broad range of plasma concentrations. Since opsonizing antibodies will be shielded from recognition by either mechanism, incorporating both capsular polysaccharides and Efb in future vaccines could be of great importance. PMID:27112346

  2. Expression of four mutant fibrinogen gammaC domains in Pichia pastoris confirms them as causes of hypofibrinogenaemia.

    PubMed

    Sheen, Campbell R; Dear, Amy; Brennan, Stephen O

    2010-10-01

    Mutations in the fibrinogen gene cluster can cause low plasma fibrinogen concentrations, known as hypofibrinogenaemia. It is important to verify whether a detected sequence variant in this cluster is deleterious or benign and this can be accomplished using protein expression systems. In this study, four mutations in the fibrinogen gammaC domain that had previously been described in patients with hypofibrinogenaemia were introduced into a gammaC construct and expressed in a Pichia pastoris yeast system to investigate their effects on protein stability and secretion. These experiments showed that the fibrinogen Middlemore (N230D), Dorfen (A289V), Mannheim II (H307Y), and Muncie (T371I) mutations were not secreted, supporting their causative role in hypofibrinogenaemia. Overexpression of the N230D, A289V and H307Y mutants revealed that the majority of the synthesised protein was retained in the endoplasmic reticulum, with only a minor proportion reaching the trans-Golgi network. Regardless, none of this protein was secreted which confirms that the four mutations investigated are indeed responsible for hypofibrinogenaemia. PMID:20580674

  3. Human fibrinogen adsorption on positively charged latex particles.

    PubMed

    Zeliszewska, Paulina; Bratek-Skicki, Anna; Adamczyk, Zbigniew; Cieśla, Michał

    2014-09-23

    Fibrinogen (Fb) adsorption on positively charged latex particles (average diameter of 800 nm) was studied using the microelectrophoretic and the concentration depletion methods based on AFM imaging. Monolayers on latex were adsorbed from diluted bulk solutions at pH 7.4 and an ionic strength in the range of 10(-3) to 0.15 M where fibrinogen molecules exhibited an average negative charge. The electrophoretic mobility of the latex after controlled fibrinogen adsorption was systematically measured. A monotonic decrease in the electrophoretic mobility of fibrinogen-covered latex was observed for all ionic strengths. The results of these experiments were interpreted according to the three-dimensional electrokinetic model. It was also determined using the concentration depletion method that fibrinogen adsorption was irreversible and the maximum coverage was equal to 0.6 mg m(-2) for ionic strength 10(-3) M and 1.3 mg m(-2) for ionic strength 0.15 M. The increase of the maximum coverage was confirmed by theoretical modeling based on the random sequential adsorption approach. Paradoxically, the maximum coverage of fibrinogen on positively charged latex particles was more than two times lower than the maximum coverage obtained for negative latex particles (3.2 mg m(-2)) at pH 7.4 and ionic strength of 0.15 M. This was interpreted as a result of the side-on adsorption of fibrinogen molecules with their negatively charged core attached to the positively charged latex surface. The stability and acid base properties of fibrinogen monolayers on latex were also determined in pH cycling experiments where it was observed that there were no irreversible conformational changes in the fibrinogen monolayers. Additionally, the zeta potential of monolayers was more positive than the zeta potential of fibrinogen in the bulk, which proves a heterogeneous charge distribution. These experimental data reveal a new, side-on adsorption mechanism of fibrinogen on positively charged surfaces and

  4. Targeting the coagulation factor fibrinogen for arthritis therapy.

    PubMed

    Raghu, Harini; Flick, Matthew J

    2011-09-01

    Fibrinogen is a provisional matrix protein of the coagulation system that following proteolytic cleavage by the protease thrombin polymerizes to form fibrin, the structural basis of the blood clot. Fibrin polymer formation at sites of vessel injury is critical to normal hemostasis. However, fibrin deposition within damaged tissues is also a common pathological feature of inflammatory diseases, including rheumatoid arthritis. Fibrin deposition has been readily detected along articular surfaces, within inflamed hyperplastic synovial tissue, and as a component of insoluble "rice bodies" within the synovial fluid of arthritic joints. Recent data has suggested that fibrin deposition within inflamed tissues is not simply a reflection of a disease process but rather actively contributes to disease pathogenesis. One mechanism that has been demonstrated to directly link fibrin(ogen) to the regulation of inflammation is the ability of fibrin(ogen) to serve as a ligand for cell-surface receptors, particularly integrins. Indeed, engagement of fibrin(ogen) by the leukocyte integrin receptor αMβ2 appears to be a common and fundamental event driving local inflammation. Recent studies have demonstrated that eliminating fibrin(ogen)-αMβ2 interactions can significantly limit the progression of multiple inflammatory diseases, including arthritis, without compromising the ability of fibrinogen to function in coagulation. These exciting findings have opened the door to new opportunities for targeting fibrinogen as an inflammatory mediator while leaving intact its hemostatic properties. PMID:21401516

  5. Fibrinogen degradation by two neutral granulocyte proteinases. Influence of calcium on the generation of fibrinogen degradation products with anticlotting properties.

    PubMed

    Bingenhkeimer, C; Gramse, M; Egbring, R; Havemann, K

    1981-07-01

    Degradation of human fibrinogen by elastase-like proteinase, chymotrypsin-like proteinase and plasmin, was done in the presence and absence of calcium ions, respectively. The resulting fibrinogen degradation products were tested for their coagulant and anti-coagulant properties. The results show that 1. fibrinogenolysis is delayed in the presence of calcium ions. Higher enzyme concentrations are required to get unclottable split products when calcium ions are present. 2. The fibrinogen fragments obtained in the presence of calcium are different in their molecular weights and anticoagulant activities compared to those obtained in the absence of calcium ions. This effect of calcium is most striking during fibrinogen cleavage by chymotrypsin-like proteinase. Elastase and plasmin-induced fibrinogenolysis was substantially influenced by calcium only at a late degradation stage. PMID:6456216

  6. Acetylation and glycation of fibrinogen in vitro occur at specific lysine residues in a concentration dependent manner: A mass spectrometric and isotope labeling study

    SciTech Connect

    Svensson, Jan; Bergman, Ann-Charlotte; Adamson, Ulf; Blombaeck, Margareta; Wallen, Hakan; Joerneskog, Gun

    2012-05-04

    Highlights: Black-Right-Pointing-Pointer Fibrinogen was incubated in vitro with glucose or aspirin. Black-Right-Pointing-Pointer Acetylations and glycations were found at twelve lysine sites by mass spectrometry. Black-Right-Pointing-Pointer The labeling by aspirin and glucose occurred dose-dependently. Black-Right-Pointing-Pointer No competition between glucose and aspirin for binding to fibrinogen was found. -- Abstract: Aspirin may exert part of its antithrombotic effects through platelet-independent mechanisms. Diabetes is a condition in which the beneficial effects of aspirin are less prominent or absent - a phenomenon called 'aspirin resistance'. We investigated whether acetylation and glycation occur at specific sites in fibrinogen and if competition between glucose and aspirin in binding to fibrinogen occurs. Our hypothesis was that such competition might be one explanation to 'aspirin resistance' in diabetes. After incubation of fibrinogen in vitro with aspirin (0.8 mM, 24 h) or glucose (100 mM, 5-10 days), we found 12 modified sites with mass spectrometric techniques. Acetylations in the {alpha}-chain: {alpha}K191, {alpha}K208, {alpha}K224, {alpha}K429, {alpha}K457, {alpha}K539, {alpha}K562, in the {beta}-chain: {beta}K233, and in the {gamma}-chain: {gamma}K170 and {gamma}K273. Glycations were found at {beta}K133 and {gamma}K75, alternatively {gamma}K85. Notably, the lysine 539 is a site involved in FXIII-mediated cross-linking of fibrin. With isotope labeling in vitro, using [{sup 14}C-acetyl]salicylic acid and [{sup 14}C]glucose, a labeling of 0.013-0.084 and 0.12-0.5 mol of acetylated and glycated adduct/mol fibrinogen, respectively, was found for clinically (12.9-100 {mu}M aspirin) and physiologically (2-8 mM glucose) relevant plasma concentrations. No competition between acetylation and glycation could be demonstrated. Thus, fibrinogen is acetylated at several lysine residues, some of which are involved in the cross-linking of fibrinogen. This may

  7. The – 148 C/T fibrinogen gene polymorphism and fibrinogen levels in ischaemic stroke: a case–control study

    PubMed Central

    van Goor, M P J; Gomez-Garcia, E; Leebeek, F; Brouwers, G; Koudstaal, P; Dippel, D

    2005-01-01

    Design: A case–control study of patients with first ever ischaemic stroke, confirmed by computed tomography. Methods: Venous blood samples were collected for fibrinogen and routine coagulation tests one week after the stroke, and after three months in about half the patients. Population controls were age and sex matched. –148 C/T fibrinogen polymorphism was determined by polymerase chain reaction followed by digestion with restriction enzymes HindIII/AluI. Results: There were 124 patients and 125 controls, mean age 56 years (range 18 to 75); 34 patients (27%) and 41 controls (33%) were heterozygous for –148 C/T fibrinogen polymorphism; six patients (5%) and five controls (4%) had the T/T genotype. The odds ratio of ischaemic stroke associated with CC homozygotes v T carriers was 0.8 (95% confidence interval, 0.5 to 1.4). Relative risk for ischaemic stroke associated with fibrinogen levels in the highest quartile was 3.9 (1.9 to 8.4) at one week, decreasing to 1.4 (0.6 to 3.3) at three months. Conclusions: –148 C/T fibrinogen gene polymorphism was not a strong risk factor for ischaemic stroke. High fibrinogen levels early after acute stroke probably represent an acute phase response. PMID:15608011

  8. Fibrinogen concentrate as first-line therapy in aortic surgery reduces transfusion requirements in patients with platelet counts over or under 100×109/L

    PubMed Central

    Solomon, Cristina; Rahe-Meyer, Niels

    2015-01-01

    Background Administration of fibrinogen concentrate, targeting improved maximum clot firmness (MCF) of the thromboelastometric fibrin-based clot quality test (FIBTEM) is effective as first-line haemostatic therapy in aortic surgery. We performed a post-hoc analysis of data from a randomised, placebo-controlled trial of fibrinogen concentrate, to investigate whether fibrinogen concentrate reduced transfusion requirements for patients with platelet counts over or under 100×109/L. Material and methods Aortic surgery patients with coagulopathic bleeding after cardiopulmonary bypass were randomised to receive either fibrinogen concentrate (n=29) or placebo (n=32). Platelet count was measured upon removal of the aortic clamp, and coagulation and haematology parameters were measured peri-operatively. Transfusion of allogeneic blood components was recorded and compared between groups. Results After cardiopulmonary bypass, haemostatic and coagulation parameters worsened in all groups; plasma fibrinogen level (determined by the Clauss method) decreased by 43–58%, platelet count by 53–64%, FIBTEM maximum clot firmness (MCF) by 38–49%, FIBTEM maximum clot elasticity (MCE) by 43–54%, extrinsically activated test (EXTEM) MCF by 11–22%, EXTEM MCE by 25–41% and the platelet component of the clot by 23–39%. Treatment with fibrinogen concentrate (mean dose 7–9 g in the 4 groups) significantly reduced post-operative allogeneic blood component transfusion requirements when compared to placebo both for patients with a platelet count ≥100×109/L and for patients with a platelet count <100×109/L. Discussion FIBTEM-guided administration of fibrinogen concentrate reduced transfusion requirements when used as a first-line haemostatic therapy during aortic surgery in patients with platelet counts over or under 100×109/L. PMID:25369608

  9. Hypodysfibrinogenaemia due to production of mutant fibrinogen alpha-chains lacking fibrinopeptide A and polymerisation knob ‘A’

    PubMed Central

    Vorjohann, Silja; Fish, Richard J.; Biron-Andreani, Christine; Nagaswami, Chandrasekaran; Weisel, John W.; Boulot, Pierre; Reyftmann, Lionel; de Moerloose, Philippe; Neerman-Arbez, Marguerite

    2011-01-01

    Summary Inherited disorders of fibrinogen are rare and affect either the quantity (hypofibrinogenaemia and afibrinogenaemia) or the quality of the circulating fibrinogen (dysfibrinogenaemia) or both (hypodysfibrinogenaemia). Extensive allelic heterogeneity has been found for all these disorders: in congenital afibrinogenaemia for example more than 40 mutations, the majority in FGA, have been identified in homozygosity or in compound heterozygosity. Numerous mutations have also been identified in patients with hypofibrinogenaemia, many of these patients are in fact heterozygous carriers of afibrinogenaemia mutations. Despite the number of genetic analyses performed, the study of additional patients still allows the identification of novel mutations. Here we describe the characterization of a novel FGA intron 2 donor splice-site mutation (Fibrinogen Montpellier II) identified in three siblings with hypodysfibrinogenaemia. Functional analysis of RNA produced by the mutant minigene in COS-7 cells revealed that the mutation led to the in-frame skipping of exon 2. Western blot analysis of COS-7 cells expressing an exon 2 deleted FGA cDNA revealed that an alpha-chain lacking exon 2, which codes in particular for fibrinopeptide A and polymerisation knob ‘A’, has the potential to be assembled into a hexamer and secreted. Analysis of precipitated fibrinogen from patient plasma showed that the defect leads to the presence in the circulation of alpha-chains lacking knob ‘A’ which is essential for the early stages of fibrin polymerisation. Fibrin made from purified patient fibrinogen clotted with thrombin displayed thinner fibers with frequent ends and large pores. PMID:20806111

  10. Hepatic Fibrinogen Storage Disease in a Patient with Hypofibrinogenemia: Report of a Case with a Missense Mutation of the FGA Gene.

    PubMed

    Lee, Michael J; Venick, Robert; Bhuta, Sunita; Li, Xinmin; Wang, Hanlin L

    2015-11-01

    We report a 9-year-old patient with abnormal liver tests found incidentally during routine bloodwork as part of a preoperative evaluation for excision of a benign cyst. A liver biopsy demonstrated hepatocytes to have pale and expanded cytoplasm that contained multiple vague globular eosinophilic inclusions. Electron microscopy showed fingerprint-like structures in the dilated cisternae of the rough endoplasmic reticulum, characteristic of fibrinogen. Whole exome sequencing identified a heterozygous missense mutation at codon 35 of the fibrinogen α (FGA) gene. No mutation was identified in the β or γ chains. His plasma fibrinogen levels were found to be decreased to 85 mg/dL (normal range 215-464). His family history was pertinent for his mother and maternal grandfather with hypofibrinogenemia. He had not had any significant bleeding episodes except for minor bruising over the shins. This case illustrates a rare etiology of storage disease that causes abnormal liver function tests. PMID:26676819

  11. Prognostic significance of preoperative fibrinogen in patients with colon cancer

    PubMed Central

    Sun, Zhen-Qiang; Han, Xiao-Na; Wang, Hai-Jiang; Tang, Yong; Zhao, Ze-Liang; Qu, Yan-Li; Xu, Rui-Wei; Liu, Yan-Yan; Yu, Xian-Bo

    2014-01-01

    AIM: To investigate the prognostic significance of preoperative fibrinogen levels in colon cancer patients. METHODS: A total of 255 colon cancer patients treated at the Affiliated Tumor Hospital of Xinjiang Medical University from June 1st 2005 to June 1st 2008 were enrolled in the study. All patients received radical surgery as their primary treatment method. Preoperative fibrinogen was detected by the Clauss method, and all patients were followed up after surgery. Preoperative fibrinogen measurements were correlated with a number of clinicopathological parameters using the Student t test and analysis of variance. Survival analyses were performed by the Kaplan-Meier method and Cox regression modeling to measure 5-year disease-free survival (DFS) and overall survival (OS). RESULTS: The mean preoperative fibrinogen concentration of all colon cancer patients was 3.17 ± 0.88 g/L. Statistically significant differences were found between preoperative fibrinogen levels and the clinicopathological parameters of age, smoking status, tumor size, tumor location, tumor-node-metastasis (TNM) stage, modified Glasgow prognostic scores (mGPS), white blood cell (WBC) count, neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and carcinoembryonic antigen (CEA) levels. Univariate survival analysis showed that TNM stage, tumor cell differentiation grade, vascular invasion, mGPS score, preoperative fibrinogen, WBC, NLR, PLR and CEA all correlated with both OS and DFS. Alpha-fetoprotein (AFP) and body mass index correlated only with OS. Kaplan-Meier analysis revealed that both OS and DFS of the total cohort, as well as of the stage II and III patients, were higher in the hypofibrinogen group compared to the hyperfibrinogen group (all P < 0.05). In contrast, there was no significant difference between OS and DFS in stage I patients with low or high fibrinogen levels. Cox regression analysis indicated preoperative fibrinogen levels, TNM stage, mGPS score, CEA, and

  12. Recombinant human fibrinogen and sulfation of the. gamma. prime chain

    SciTech Connect

    Farrell, D.H.; Huang, S.; Chung, D.W.; Davie, E.W. ); Mulvihill, E.R. )

    1991-10-01

    Human fibrinogen and the homodimeric {gamma}{prime}-chain-containing variant have been expressed in BHK cells using cDNAs coding for the {alpha},{beta}, and {gamma} (or {gamma}{prime}) chains. The fibrinogens were secreted at levels greater than 4 {mu}g (mg of total cell protein){sup {minus}1}day{sup {minus}1} and were biologically active in clotting assays. Recombinant fibrinogen containing the {gamma}' chain incorporated {sup 35}SO{sub 4} into its chains during biosynthesis, while no incorporation occurred in the protein containing the {gamma} chain. The identity of the sulfated {gamma}{prime} chain was verified by its ability to form dimers during clotting. In addition, carboxypeptidase {Upsilon} digestion of the recombinant fibrinogen containing the {gamma}{prime} chain released 96% of the {sup 35}S label from the sulfated chain, and the radioactive material was identified as tyrosine O-sulfate. These results clarify previous findings of the sulfation of tyrosine in human fibrinogen.

  13. "Fibrinogen Tokyo II". An abnormal fibrinogen with an impaired polymerization site on the aligned DD domain of fibrin molecules.

    PubMed Central

    Matsuda, M; Baba, M; Morimoto, K; Nakamikawa, C

    1983-01-01

    A hereditary dysfibrinogenemia associated with defective aggregation of fibrin monomers was found in a 39-yr-old female and in the members of her immediate family, who had all been asymptomatic. The abnormality was probably due to an impaired polymerization site exposed in the DD domain of two adjacent fibrin molecules, because plasmic fragment DD derived from the propositus' cross-linked fibrin bound far less tightly to insolubilized normal fragment E than that from the normal one. Its complementary polymerization site in the E domain of fibrin, which was exposed by thrombin cleavage, and the polymerization site in the D domain of fibrinogen, which was available without activation by thrombin, were both found to be normal. More anodal migration of the abnormal fragment DD than the normal one, as shown by immunoelectrophoresis, seemed to support our concept that the mutation most likely resides in the D domain of the abnormal fibrinogen molecule at or near a region closely related to the polymerization site that is exposed when two fibrin molecules are linearly aligned. The work of others on the polymerization of normal fibrin with different techniques yielded results consistent with our conclusions. We tentatively designate this type of abnormal fibrinogen "fibrinogen Tokyo II," but its possible identity with other abnormalities of fibrinogen reported heretofore is not excluded. Images FIGURE 1 FIGURE 5 FIGURE 7 PMID:6886002

  14. The proteolytic action of Arvin on human fibrinogen

    PubMed Central

    Ewart, M. R.; Hatton, M. W. C.; Basford, J. M.; Dodgson, K. S.

    1970-01-01

    1. Human fibrinogen was subjected to proteolysis by enzyme preparations (clinical Arvin and IRC-50 Arvin) from the venom of Agkistrodon rhodostoma. 2. IRC-50 Arvin releases three peptides from fibrinogen, and these were identified as fibrinopeptides AP, AY and A. 3. The less purified `clinical' Arvin releases, in addition to fibrinopeptides AP, AY and A, small amounts of two heptapeptides derived from fibrinopeptides AP and A, probably because it contains another enzyme as well as Arvin. 4. No fibrinopeptide B is released by either Arvin preparation. 5. Thus, although Arvin is known to differ from `reptilase' from Bothrops jararaca in that it does not activate the enzyme that cross-links fibrin (fibrin-stabilizing factor), it is identical with reptilase with respect to the peptides that it liberates from fibrinogen. PMID:5529716

  15. Biosynthesis, assembly and secretion of fibrinogen in cultured rat hepatocytes.

    PubMed Central

    Hirose, S; Oda, K; Ikehara, Y

    1988-01-01

    The biosynthesis, assembly and secretion of fibrinogen were investigated in cultured rat hepatocytes which were incubated with [35S]methionine. When initial rates of the synthesis of three fibrinogen subunits were compared, the A alpha-subunit was found to be synthesized significantly slower than the B beta- and gamma-subunits. Pulse-chase experiments revealed that the secreted fibrinogen contained different proportions of the newly synthesized subunits, depending upon the chase times. Radioactivity in the A alpha subunit, which initially had the highest level of the three, was rapidly decreased in parallel with the chase time. The gamma-subunit had an increasing amount of the radioactivity in the secreted molecule during the chase periods, whereas that in the B beta-subunit was gradually decreased at the later stages of chase. Analysis of intracellular components of fibrinogen confirmed that the nascent A alpha-subunit was most rapidly exhausted, and the gamma-subunit occupied the largest proportion among the non-assembled subunits at later stages of chase. Taken together, these results suggest that the synthesis of A alpha-subunit, which has the lowest rate, could be the rate-limiting step in the production and secretion of fibrinogen in cultured rat hepatocytes, in contrast with what has been proposed for human and rabbit fibrinogen, namely that the synthesis of B beta-subunit is the rate-limiting step. The results also indicate that there is a large intracellular pool of gamma-subunit. Images Fig. 2. Fig. 3. PMID:3401211

  16. Effects of Fibrinogen on RBC Aggregation and Rouleux Formation

    NASA Astrophysics Data System (ADS)

    Fedosov, Dmitry; Pan, Wenxiao; Caswell, Bruce; Gompper, Gerhard; Karniadakis, George

    2010-11-01

    We employ dissipative particle dynamics (DPD) to study human blood rheology. Specifically, using a multi-scale (MS-RBC) and low-dimensional model (LD-RBC) for modeling red blood cells (RBCs), we study the role of fibrinogen inter-cellular forces in the formation of rouleaux structures at low shear rates. In particular, both models verify that RBC aggregation into rouleaux determines non-Newtonian response and they also predict a non-zero yield stress whose value depends on the fibrinogen concentration.

  17. Bacteroides gingivalis and Bacteroides intermedius recognize different sites on human fibrinogen

    SciTech Connect

    Lantz, M.S.; Allen, R.D.; Bounelis, P.; Switalski, L.M.; Hook, M. )

    1990-02-01

    Bacteroides (Porphyromonas) gingivalis and Bacteroides (Porphyromonas) intermedius have been implicated in the etiology of human periodontal diseases. These organisms are able to bind and degrade human fibrinogen, and these interactions may play a role in the pathogenesis of periodontal disease. In attempts to map the bacterial binding sites along the fibrinogen molecule, we have found that strains of B. gingivalis and B. intermedius, respectively, recognize spatially distant and distinct sites on the fibrinogen molecule. Isolated reduced and alkylated alpha-, beta-, and gamma-fibrinogen chains inhibited binding of 125I-fibrinogen to both Bacteroides species in a concentration-dependent manner. Plasmin fragments D and to some extent fragment E, however, produced a concentration-dependent inhibition of 125I-fibrinogen binding to B. intermedius strains but did not affect binding of 125I-fibrinogen to B. gingivalis strains. Radiolabeled fibrinogen chains and fragments were compared with 125I-fibrinogen with respect to specificity and reversibility of binding to bacteria. According to these criteria, gamma chain most closely resembled the native fibrinogen molecule in behavior toward B. gingivalis strains and fragments D most closely resembled fibrinogen in behavior toward B. intermedius strains. The ability of anti-human fibrinogen immunoglobulin G (IgG) to inhibit binding of 125I-fibrinogen to B. intermedius strains was greatly reduced by absorbing the IgG with fragments D. Absorbing the IgG with fragments D had no effect on the ability of the antibody to inhibit binding of 125I-fibrinogen to B. gingivalis strains. A purified staphylococcal fibrinogen-binding protein blocked binding of 125I-fibrinogen to B. intermedius strains but not to B. gingivalis strains.

  18. Influence of a constant magnetic field on the fibrinogen-fibrin system. [in blood coagulation process

    NASA Technical Reports Server (NTRS)

    Matskevichene, V. B.; Platonova, A. T.

    1974-01-01

    The effect of a constant magnetic field with a strength of 2500 oersteds on the fibrinogen-fibrin system was studied in the organism of healthy rabbits with exposure times of 1 and 5 hours. The results obtained indicate disruptions in the stage of conversion of fibrinogen to fibrin and an increase in the amount of fibrinogen.

  19. Extraction, radiolabeling, and in vivo catabolism of autologous-origin equine fibrinogen and platelets in the healthy and exercise-stressed horse

    SciTech Connect

    Coyne, C.P.

    1986-01-01

    Three separate techniques were evaluated for the extraction of autologous-origin fibrinogen from whole equine plasma. Rapid extraction of equine fibrinogen with ammonium sulfate-sodium phosphate buffer, in combination with saturated glycine buffer, provided the most practical means of obtaining a protein extract with the highest degree of biological activity and sufficiently high iodine-125 (/sup 125/I) radiolabeling efficiencies using monochloroiodine reagent (ICI). A technique was developed for the in vitro radiolabeling of equine platelets suspended in plasma. This entailed the use of the isotope, indium-111 (/sup 111/In), together with the lipophilic ligand, 2-(mercaptopyridine-N-oxide). This labeling technique achieved labeling efficiencies between 75% and 96%, and in vitro aggregability of /sup 111/In-merc radiolabeled platelets was comparable to that of unlabeled cell isolates. In the final phase of the investigation, autologous-origin /sup 125/I-labeled fibrinogen and /sup 111/In-labeled platelets were applied in a series of equine exercise physiology studies. Elimination of these two radiobiologicals was evaluated in the resting and exercise-stressed horse. Results from these investigations revealed no long-term influence of exercise conditioning on the in vivo kinetics of radiolabeled fibrinogen or platelets.

  20. Common variation in the C-terminal region of the fibrinogen beta-chain: effects on fibrin structure, fibrinolysis and clot rigidity.

    PubMed

    Ajjan, Ramzi; Lim, Bernard C B; Standeven, Kristina F; Harrand, Robert; Dolling, Sarah; Phoenix, Fladia; Greaves, Richard; Abou-Saleh, Radwa H; Connell, Simon; Smith, D Alastair M; Weisel, John W; Grant, Peter J; Ariëns, Robert A S

    2008-01-15

    Fibrinogen BbetaArg448Lys is a common polymorphism, positioned within the carboxyl terminus of the Bbeta-chain of the molecule. Studies suggest that it is associated with severity of coronary artery disease and development of stroke. The effects of the amino acid substitution on clot structure remains controversial, and the aim of this study was to investigate the effect(s) of this polymorphism on fibrin clot structure using recombinant techniques. Permeation, turbidity, and scanning electron microscopy showed that recombinant Lys448 fibrin had a significantly more compact structure, with thin fibers and small pores, compared with Arg448. Clot stiffness, measured by means of a novel method using magnetic tweezers, was significantly higher for the Lys448 compared with the Arg448 variant. Clots made from recombinant protein variants had similar lysis rates outside the plasma environment, but when added to fibrinogen-depleted plasma, the fibrinolysis rates for Lys448 were significantly slower compared with Arg448. This study demonstrates for the first time that clots made from recombinant BbetaLys448 fibrinogen are characterized by thin fibers and small pores, show increased stiffness, and appear more resistant to fibrinolysis. Fibrinogen BbetaArg448Lys is a primary example of common genetic variation with a significant phenotypic effect at the molecular level. PMID:17925485

  1. Fasting glucose levels within the high normal range predict cardiovascular outcome

    PubMed Central

    Shaye, Kivity; Amir, Tirosh; Shlomo, Segev; Yechezkel, Sidi

    2016-01-01

    Background Diabetes mellitus and impaired glucose metabolism are associated with increased risk for cardiovascular disease (CVD). However, it is still not clear whether glucose levels can predict CVD risk among patients without diabetes. The primary aim of this study is to assess whether normoglycemic fasting plasma glucose (FPG) is associated with increased risk of CVD outcomes in healthy patients. Methods We obtained blood measurements, data from physical examination, and medical and lifestyle information from 10,913 men and women who were evaluated in the Institute for Preventive Medicine of Sheba Medical Center. Enrolled were participants with FPG <100 mg/dL as well as 100 to 125 mg/dL, who were free of diagnosis of CVD. The participants were actively screened for coronary disease using a stress test. Primary end points were coronary heart disease or self-reported cerebral vascular disease. Results A total of 1,119 incident cases of CVD occurred during a mean follow-up of 4.3 years. Subjects with fasting glucose levels in the high normal range (95–99 mg/dL) had an increased CVD risk when compared with levels <80 mg/dL, (HR 1.53;CI 95% [1.22–1.91], P < .001). A multivariate model, adjusted for age, sex, family history of CVD, blood pressure, body mass index, smoking status, pharmacologic treatment, serum triglycerides, and high-density lipoprotein and low-density lipoprotein cholesterol levels, revealed an independent increased risk of CVD with rising FPG levels in the normal range. Conclusion Elevated CVD risk is strongly and independently associated with glucose levels within the normoglycemic range. Fasting plasma glucose may help in identifying apparently healthy persons with early metabolic abnormalities who are at increased risk for CVD before progression to prediabetes and overt diabetes mellitus. PMID:22795290

  2. Evaluation of Fibrinogen Self-assembly: Role of its alphaC Region

    SciTech Connect

    J Koo; M Rafailovich; L Medved; G Tsurupa; B Kudryk; y Liu; D Galanakis

    2011-12-31

    Background: Exposure of cryptic, functional sites on fibrinogen upon its adsorption to hydrophobic surfaces of biomaterials has been linked to an inflammatory response and fibrosis. Such adsorption also induces ordered fibrinogen aggregation which is poorly understood. Objective: To investigate hydrophobic surface-induced fibrinogen aggregation. Methods: Contact and lateral force scanning probe microscopy, yielding topography, image dimensions and fiber elastic modulus measurements were used along with transmission and scanning electron microscopy. Fibrinogen aggregation was induced under non-enzymatic conditions by adsorption on a trioctyl-surface monolayer (trioctylmethylamine) grafted onto silica clay plates. Results: A more than one molecule thick coating was generated by adsorption on the plate from 100 to 200 {mu}g mL{sup -1} fibrinogen solutions, and three-dimensional networks formed from 4 mg mL{sup -1} fibrinogen incubated with uncoated or fibrinogen-coated plates. Fibrils appeared laterally assembled into branching and overlapping fibers whose heights from the surface ranged from approximately 3 to 740 nm. The elastic modulus of fibrinogen fibers was 1.55 MPa. No fibrils formed when fibrinogen lacking {alpha}C-domains was used as a coating or was incubated with intact fibrinogen-coated plates, or when the latter plates were sequentially incubated with anti-A{alpha}529-539 mAb and intact fibrinogen. When an anti-A{alpha}241-476 mAb was used instead, fine, long fibers formed. Similarly, sequential incubations of fibrinogen-coated plates with recombinant {alpha}C-domain (A{alpha}392-610 fragment) or {alpha}C-connector (A{alpha}221-372 fragment) and fibrinogen resulted in distinctly fine fiber networks. Conclusions: Adsorption-induced fibrinogen self-assembly is initiated by a more than one molecule-thick surface layer and eventuates in three-dimensional networks whose formation requires fibrinogen with intact {alpha}C-domains.

  3. Fibrinogen blocks the autoactivation and thrombin-mediated activation of factor XI on dextran sulfate.

    PubMed Central

    Scott, C F; Colman, R W

    1992-01-01

    The intrinsic pathway of blood coagulation is activated when factor XIa, one of the three contact-system enzymes, is generated and then activates factor IX. Factor XI has been shown to be efficiently activated in vitro by surface-bound factor XIIa after factor XI is transported to the surface by its cofactor, high molecular weight kininogen (HK). However, individuals lacking any of the three contact-system proteins--namely, factor XII, prekallikrein, and HK--do not suffer from bleeding abnormalities. This mystery has led several investigators to search for an "alternate" activation pathway for factor XI. Recently, factor XI has been reported to be autoactivated on the soluble "surface" dextran sulfate, and thrombin was shown to accelerate the autoactivation. However, it was also reported that HK, the cofactor for factor XIIa-mediated activation of factor XI, actually diminishes the thrombin-catalyzed activation rate of factor XI. Nonetheless, it was suggested that thrombin was a more efficient activator than factor XIIa. In this report we investigated the effect of fibrinogen, the major coagulation protein in plasma, on the activation rate of factor XI. Fibrinogen, the preferred substrate for thrombin in plasma, virtually prevented autoactivation of factor XI as well as the thrombin-mediated activation of factor XI, while having no effect on factor XIIa-catalyzed activation. HK dramatically curtailed the autoactivation of factor XI in addition to the thrombin-mediated activation. These data indicate that factor XI would not be autoactivated in a plasma environment, and thrombin would, therefore, be unlikely to potentiate the activation. We believe that the "missing pathway" for factor XI activation remains an enigma that warrants further investigation. PMID:1454798

  4. Fibrinogen, an endogenous ligand of Toll-like receptor 4, activates monocytes in pre-eclamptic patients.

    PubMed

    Al-ofi, Ebtisam; Coffelt, Seth B; Anumba, Dilly O

    2014-06-01

    Pre-eclampsia (PE) remains the leading cause of pregnancy-associated mortality and morbidity, urging the need for a better understanding of its aetiology and pathophysiological progression. A key characteristic of PE is a systemic, exaggerated, inflammatory condition involving abnormal cytokine levels in serum, altered immune cell phenotype and Th1/Th2-type immunological imbalance. However, it is unknown how this heightened inflammatory condition manifests. We previously reported increased expression of the lipopolysaccharide receptor, Toll-like receptor 4 (TLR4), on monocytes from PE patients compared with normotensive, pregnant patients (NP). This upregulation of TLR4 on PE monocytes was accompanied by a hyper-responsiveness to bacterial TLR4 ligands. To determine whether non-microbial, endogenous TLR4 ligands also activate monocytes from PE patients, we investigated the expression of host-derived TLR4 ligands and the response of monocytes to these endogenous ligands. Plasma levels of fibrinogen - but not fibronectin or heparan sulphate - were higher in PE patients than in NP. Exposure to fibrinogen was associated with significantly increased production of inflammatory cytokines by monocytes from PE patients. Interestingly, this effect was not observed with NP monocytes. Our findings suggest that the fibrinogen-TLR4 axis might play an important role in the atypical activation of monocytes observed in PE patients that may contribute to the exaggerated inflammatory condition. PMID:24661950

  5. Four-Group Classification Based on Fibrinogen Level and Fibrin Polymerization Associated With Postoperative Bleeding in Cardiac Surgery.

    PubMed

    Kawashima, Shingo; Suzuki, Yuji; Sato, Tsunehisa; Kikura, Mutsuhito; Katoh, Takasumi; Sato, Shigehito

    2016-10-01

    Fibrinogen and fibrin formation have a key role in perioperative hemostasis. The aim of this study is to examine the association of postoperative hemostasis with a combined evaluation of the fibrinogen level and fibrin polymerization in cardiac surgery. We retrospectively classified 215 consecutive cardiac surgery patients into 4 groups (Fuji-san classification) that were divided by fibrinogen level <150 mg/dL (ie, hypofibrinogenemia) and fibrinogen thromboelastometry value at 10 minutes with rotational thromboelastometry <6 mm (ie, low fibrin polymerization) at the warming of cardiopulmonary bypass. Four groups resulted; group I, the acceptable range (n = 85); group II, only hypofibrinogenemia (<150 mg/dL, ≥6 mm, n = 63); group III, hypofibrinogenemia and low fibrin polymerization (<150 mg/dL, <6 mm, n = 60); and group IV, only low fibrin polymerization (≥150 mg/dL, <6 mm, n = 7). The risk of chest tube drainage volume greater than 500 mL within the first 24 hours after surgery (with group I as the reference) was increased in group II (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.5-7.4; P < .01) and group III (OR, 8.5; 95% CI, 3.5-21.7; P < .01), and the risk greater than 1000 mL (with group I as the reference) was increased in group III (OR, 4.0; 95% CI, 1.1-17.3; P = .03) and group IV (OR, 23.1; 95% CI, 3.2-201.0; P < .01). Intraoperative blood transfusions were decreased by 24.5%, after stratifying the starting amount of fresh frozen plasma by the 4-group classification in the recent consecutive 65 (30.2%) patients (P < .01). The 4-group classification is associated with postoperative bleeding and may improve the quality of perioperative blood transfusion in cardiac surgery. PMID:26207020

  6. Specific cell components of Bacteroides gingivalis mediate binding and degradation of human fibrinogen.

    PubMed Central

    Lantz, M S; Allen, R D; Vail, T A; Switalski, L M; Hook, M

    1991-01-01

    Bacteroides (Porphyromonas) gingivalis, which has been implicated as an etiologic agent in human periodontal diseases, has been shown to bind and degrade human fibrinogen. B. gingivalis strains bind fibrinogen reversibly and with high affinity and bind to a specific region of the fibrinogen molecule that appears to be located between the D and E domains (M. S. Lantz, R. D. Allen, P. Bounelis, L. M. Switalski, and M. Hook, J. Bacteriol. 172:716-726, 1990). We now report that human fibrinogen is bound and then degraded by specific B. gingivalis components that appear to be localized at the cell surface. Fibrinogen binding to bacterial cells occurred at 4, 22, and 37 degrees C. A functional fibrinogen-binding component (Mr, 150,000) was identified when sodium dodecyl sulfate-solubilized bacteria were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to nitrocellulose membranes, and probed with 125I-fibrinogen. Fibrinogen degradation did not occur at 4 degrees C but did occur at 22 and 37 degrees C. When bacteria and iodinated fibrinogen were incubated at 37 degrees C, two major fibrinogen fragments (Mr, 97,000 and 50,000) accumulated in incubation mixture supernatant fractions. Two major fibrinogen-degrading components (Mr, 120,000 and 150,000) have been identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in substrate-containing gels. Fibrinogen degradation by the Mr-120,000 and -150,000 proteases was enhanced by reducing agents, completely inhibited by N-alpha-p-tosyl-L-lysyl chloromethyl ketone, and partially inhibited by n-ethyl maleimide, suggesting that these enzymes are thiol-dependent proteases with trypsinlike substrate specificity. The fibrinogen-binding component could be separated from the fibrinogen-degrading components by selective solubilization of bacteria in sodium deoxycholate. Images PMID:1987144

  7. Time-dependent association between platelet-bound fibrinogen and the Triton X-100 insoluble cytoskeleton

    SciTech Connect

    Peerschke, E.I. )

    1991-02-01

    Previous studies indicated a correlation between the formation of EDTA-resistant (irreversible) platelet-fibrinogen interactions and platelet cytoskeleton formation. The present study explored the direct association of membrane-bound fibrinogen with the Triton X-100 insoluble cytoskeleton of aspirin-treated, gel-filtered platelets, activated but not aggregated with 20 mumol/L adenosine diphosphate (ADP) or 150 mU/mL human thrombin (THR) when bound fibrinogen had become resistant to dissociation by EDTA. Conversion of exogenous 125I-fibrinogen to fibrin was prevented by adding Gly-Pro-Arg and neutralizing THR with hirudin before initiating binding studies. After 60 minutes at 22 degrees C, the cytoskeleton of ADP-treated platelets contained 20% +/- 12% (mean +/- SD, n = 14) of membrane-bound 125I-fibrinogen, representing 10% to 50% of EDTA-resistant fibrinogen binding. The THR-activated cytoskeleton contained 45% +/- 15% of platelet bound fibrinogen, comprising 80% to 100% of EDTA-resistant fibrinogen binding. 125I-fibrinogen was not recovered with platelet cytoskeletons if binding was inhibited by the RGDS peptide, excess unlabeled fibrinogen, or disruption of the glycoprotein (GP) IIb-IIIa complex by EDTA-treatment. Both development of EDTA-resistant fibrinogen binding and fibrinogen association with the cytoskeleton were time dependent and reached maxima 45 to 60 minutes after fibrinogen binding to stimulated platelets. Although a larger cytoskeleton formed after platelet stimulation with thrombin as compared with ADP, no change in cytoskeleton composition was noted with development of EDTA-resistant fibrinogen binding.

  8. The reduced soluble fibrinogen-like protein 2 and regulatory T cells in acute coronary syndrome.

    PubMed

    Liu, Kun; Li, Ting; Huang, Shiyuan; Long, Rui; You, Ya; Liu, Jinping; Wang, Zhaohui

    2016-02-01

    Soluble fibrinogen-like protein 2, sfgl2, is the new effector of CD4(+)CD25(+)FOXP3(+) regulatory T cell (Treg) and exerts immunosuppressive activity. We design this study to investigate the possible role of sfgl2 in atherosclerosis. A total of 58 acute coronary syndrome (ACS) patients, together with 22 stable angina (SA) patients and 31 normal coronary artery (NCA) people were enrolled in our study. Serum level of sfgl2 and plasma level of Treg were respectively measured. In line with the change of Treg, serum level of sfgl2 in ACS (8.70 ng/mL) was significantly decreased (P = 0.003), compared with that in SA (11.86 ng/mL) and NCA (17.55 ng/mL). Both sfgl2 and Treg level were obviously decreased in ACS; Sfgl2 may play a protective role in atherosclerosis. PMID:26515143

  9. Influence of fibrinogen and C-RP on progression of peripheral arterial disease in type 2 diabetes: a preliminary report

    PubMed Central

    2013-01-01

    Background Limited studies have suggested that inflammatory biomarkers play a role in the initiation and progression of atherosclerosis in diabetic patients. This study assesses the effect of inflammatory biomarkers: fibrinogen and C-reactive protein (C-RP) on the progression of peripheral arterial disease (PAD) in type 2 diabetic (T2D) patients. Methods Sixty two patients with T2D and PAD (mean age 60.28 ± 27 years and diabetes duration of 8.58 ± 6.17 years) were enrolled in a cohort prospective study of 36 months. Ankle-brachial index (ABI) was measured in all patients at baseline and after 36 months. Multiple linear regression analysis was used to determine the predictivity of variables for fibrinogen, C-RP, plasma lipid fractions, fasting plasma glucose, Body Mass Index (BMI), duration of diabetes status and the age on changes in ABI value. Results Linear regression analysis defined F as a predictor for endpoint value of ABI (β = 0.469, p = 0.007). Value of C-RP determinates change of minimal value of ABI (β = 0.449, p = 0.037) and change of mean ABI per year (β = 0.442, p = 0.025). Conclusion Our data indicate that plasma determination of fibrinogen and C-RP might have a clinical implication in defining the process of progression of PAD in T2D population. PMID:23375154

  10. Surface characterization and AFM imaging of mixed fibrinogen-surfactant films.

    PubMed

    Hassan, Natalia; Maldonado-Valderrama, Julia; Gunning, A Patrick; Morris, Victor J; Ruso, Juan M

    2011-05-19

    This study describes the adsorption behavior of mixed protein/surfactant systems at the air-water interface: specifically fibrinogen and the fluorinated and hydrogenated surfactants (C(8)FONa, C(8)HONa, and C(12)HONa). Surface tension techniques and atomic force microscopy (AFM) have been combined to investigate the adsorption behavior of these mixed systems. Interfacial rheology showed that fibrinogen has a low dilatational modulus at the air-water interface when compared to other proteins, suggesting the formation of a weak surface network. Fluorinated and hydrogenated surfactants severely decreased the dilatational modulus of the adsorbed fibrinogen film at the air-water interface. These measurements suggest the progressive displacement of fibrinogen from the air-water interface by both types of surfactants. However, in the case of fibrinogen/fluorinated surfactant systems, surface tension and dilatational rheology measurements suggest the formation of complexes with improved surface activity. AFM imaging of fibrinogen in the presence and absence of surfactants provided new information on the structure of mixed surface films, and revealed new features of the interaction of fibrinogen with hydrogenated and fluorinated surfactants. These studies suggest complexes formed between fibrinogen and fluorinated surfactants which are more surface active than fibrinogen, while the absence of interaction between fibrinogen and hydrogenated surfactants (C(8)HONa and C(12)HONa) results in compaction of the surface layer. PMID:21491854

  11. Thyroid Levels in High-Normal Range May Be Linked to Cardiac Arrest

    MedlinePlus

    ... in High-Normal Range May Be Linked to Cardiac Arrest Study isn't cause for alarm, cardiologist says, ... Services, or federal policy. More Health News on: Cardiac Arrest Thyroid Tests Recent Health News Related MedlinePlus Health ...

  12. Linkage study of fibrinogen levels: the Strong Heart Family Study

    PubMed Central

    Best, Lyle G; North, Kari E; Li, Xia; Palmieri, Vittorio; Umans, Jason G; MacCluer, Jean; Laston, Sandy; Haack, Karin; Goring, Harald; Diego, Vincent P; Almasy, Laura; Lee, Elisa T; Tracy, Russell P; Cole, Shelley

    2008-01-01

    Background The pathogenesis of atherosclerosis involves both hemostatic and inflammatory mechanisms. Fibrinogen is associated with both risk of thrombosis and inflammation. A recent meta-analysis showed that risk of coronary heart disease may increase 1.8 fold for 1 g/L of increased fibrinogen, independent of traditional risk factors. It is known that fibrinogen levels may be influenced by demographic, environmental and genetic factors. Epidemiologic and candidate gene studies are available; but few genome-wide linkage studies have been conducted, particularly in minority populations. The Strong Heart Study has demonstrated an increased incidence of cardiovascular disease in the American Indian population, and therefore represents an important source for genetic-epidemiological investigations. Methods The Strong Heart Family Study enrolled over 3,600 American Indian participants in large, multi-generational families, ascertained from an ongoing population-based study in the same communities. Fibrinogen was determined using standard technique in a central laboratory and extensive additional phenotypic measures were obtained. Participants were genotyped for 382 short tandem repeat markers distributed throughout the genome; and results were analyzed using a variance decomposition method, as implemented in the SOLAR 2.0 program. Results Data from 3535 participants were included and after step-wise, linear regression analysis, two models were selected for investigation. Basic demographic adjustments constituted model 1, while model 2 considered waist circumference, diabetes mellitus and postmenopausal status as additional covariates. Five LOD scores between 1.82 and 3.02 were identified, with the maximally adjusted model showing the highest score on chromosome 7 at 28 cM. Genes for two key components of the inflammatory response, i.e. interleukin-6 and "signal transducer and activator of transcription 3" (STAT3), were identified within 2 and 8 Mb of this 1 LOD drop

  13. Effects of fibrinogens on phase transitions in lipid model membrane systems.

    PubMed

    Cunningham, B A; Küçük, O; Kwaan, H C; Westerman, M P; Tracy, D; Lis, L J

    1994-06-24

    An abnormal fibrinogen that caused aggregation of red blood cells (RBC) in a patient with gangrene was examined by real-time X-ray diffraction to determine its effects on dipalmitoylphosphatidylcholine (DPPC) and 1-palmitoyl-2-oleoylphosphatidylethanolamine (POPE) phase transitions. Similar studies were done with normal fibrinogen and results were compared. Both types of fibrinogen slightly increased the L alpha-->HII phase transition temperature and the HII phase parameters for POPE, while neither fibrinogen significantly affected the order-disordered acyl chain transitions in the lipid bilayer phase. However, fibrinogen differentially influenced the bilayer unit cell parameter of the gel and disordered bilayer and the gel state ripple phase. These results can be interpreted as indicating that fibrinogen has little effect on the balance of gel and disordered acyl chains in the lipid bilayer, but may influence membrane functions dependent on non-bilayer phases. PMID:7923477

  14. FDP-E induces adipocyte inflammation and suppresses insulin-stimulated glucose disposal: effect of inflammation and obesity on fibrinogen Bβ mRNA.

    PubMed

    Kang, Minsung; Vaughan, Roger A; Paton, Chad M

    2015-12-01

    Obesity is associated with increased fibrinogen production and fibrin formation, which produces fibrin degradation products (FDP-E and FDP-D). Fibrin and FDPs both contribute to inflammation, which would be expected to suppress glucose uptake and insulin signaling in adipose tissue, yet the effect of FDP-E and FDP-D on adipocyte function and glucose disposal is completely unknown. We tested the effects of FDPs on inflammation in 3T3-L1 adipocytes and primary macrophages and adipocyte glucose uptake in vitro. High-fat-fed mice increased hepatic fibrinogen mRNA expression ninefold over chow-fed mice, with concomitant increases in plasma fibrinogen protein levels. Obese mice also displayed increased fibrinogen content of epididymal fat pads. We treated cultured 3T3-L1 adipocytes and primary macrophages with FDP-E, FDP-D, or fibrinogen degradation products (FgnDP-E). FDP-D and FgnDP-E had no effect on inflammation or glucose uptake. Cytokine mRNA expression in RAW264.7 macrophage-like cells and 3T3-L1 adipocytes treated with FDP-E induced inflammation with maximal effects at 100 nM and 6 h. Insulin-stimulated 2-deoxy-d-[(3)H]glucose uptake was reduced by 71% in adipocytes treated with FDP-E. FDP-E, but not FDP-D or FgnDP-E, induces inflammation in macrophages and adipocytes and decreases glucose uptake in vitro. FDP-E may contribute toward obesity-associated acute inflammation and glucose intolerance, although its chronic role in obesity remains to be elucidated. PMID:26447203

  15. Effect of fibrinogen on blood coagulation detected by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Xu, Xiangqun; Teng, Xiangshuai

    2015-05-01

    Our previous work demonstrated that an optical coherence tomography (OCT) technique and the parameter 1/e light penetration depth (d1/e) were able to characterize the whole blood coagulation process in contrast to existing optical tests that are performed on plasma samples. To evaluate the feasibility of the technique for quantifying the effect of fibrinogen (Fbg) on blood coagulation, a dynamic study of d1/e of blood in various Fbg concentrations was performed in static state. Two groups of blood samples of hematocrit (HCT) in 35, 45, and 55% were reconstituted of red blood cells with: 1) treated plasma with its intrinsic Fbg removed and commercial Fbg added (0-8 g L-1) and 2) native plasma with commercial Fbg added (0-8 g L-1). The results revealed a typical behavior due to coagulation induced by calcium ions and the clotting time is Fbg concentration-dependent. The clotting time was decreased by the increasing amount of Fbg in both groups. Besides, the blood of lower HCT with various levels of Fbg took shorter time to coagulate than that of higher HCT. Consequently, the OCT method is a useful and promising tool for the detection of blood-coagulation processes induced with different Fbg levels.

  16. Potential basis for regulation of the coordinately expressed fibrinogen genes: homology in the 5' flanking regions.

    PubMed Central

    Fowlkes, D M; Mullis, N T; Comeau, C M; Crabtree, G R

    1984-01-01

    The three chains of fibrinogen are encoded by three separate genes whose transcription is coordinately regulated. The breakdown of fibrinogen during the acute-phase reaction leads to a simultaneous increase in alpha-, beta-, and gamma-fibrinogen mRNA in the liver. In a search for the basis of this coordinate increase in transcription, we have determined the sequences of the regions surrounding the points of transcriptional initiation of the three rat fibrinogen genes, 1490 nucleotides upstream and 730 nucleotides downstream. Two unique regions of homology have been found. One region consists of 15 nucleotides that have a common 6-nucleotide core lying between -116 and -160; the other is approximately equal to 100 nucleotides long and is in the -165 to -472 region. In this region, the beta- and gamma-fibrinogen genes are approximately equal to 65% homologous. alpha-Fibrinogen has somewhat less homology with both beta- and gamma-fibrinogen. In addition, the beta-fibrinogen gene has 22 nucleotides at position -480 that are homologous to sequences that have been noted to occur in glucocorticosteroid-regulated genes in a similar position. We feel that these areas of conserved sequences play a role in the regulation of the transcription of fibrinogen. The fibrinogen chains are synthesized as precursor peptides, and the amino-terminal portion, the so-called signal peptide, is removed during the translocation of the peptide chain across the endoplasmic reticulum. We have determined those sequences that encode the signal peptides. Homology in the amino acid sequence between the rat and human signal peptides varies between 52% for alpha-fibrinogen and 66% for beta-fibrinogen. This homology implies that there has been strong selective pressure on this portion of these genes. PMID:6232608

  17. Exposure of fibrinogen receptors in human platelets by surface proteolysis with elastase.

    PubMed Central

    Kornecki, E; Ehrlich, Y H; De Mars, D D; Lenox, R H

    1986-01-01

    Human platelets that were preincubated with porcine elastase aggregated spontaneously upon the addition of fibrinogen. Maximal aggregation to fibrinogen was observed with platelets pretreated with an elastase concentration of 111 micrograms/ml, and half-maximal aggregation occurred after treatment with 11 micrograms/ml elastase. Binding of radiolabeled fibrinogen to elastase-treated platelets was specific, saturable, and showed a single class of 48,400 +/- 9,697 fibrinogen-binding sites per platelet with a dissociation constant of 6.30 +/- 1.48 X 10(-7) M. ATP, apyrase, and the stimulators of platelet adenylate cyclase forskolin, prostaglandin E1, prostacyclin, and N6, 2'-O-dibutyryl cyclic AMP did not inhibit the fibrinogen-induced aggregation of elastase-treated platelets. EDTA completely blocked the initiation of aggregation and reversed the fibrinogen-induced aggregation of elastase-treated platelets. Monoclonal and polyclonal antibodies directed against glycoproteins (GP) IIb and IIIa completely blocked the fibrinogen-induced aggregation of elastase-treated platelets. Immunoprecipitates with these antibodies obtained from detergent extracts of surface-radiolabeled, intact, and elastase-treated platelets contained the glycoproteins IIb and IIIa. We conclude that surface proteolysis by low concentrations of elastase can expose fibrinogen-binding sites associated with GPIIb and GPIIIa on the platelet surface, resulting in spontaneous aggregation upon the addition of fibrinogen. These findings may be relevant to hemostatic changes observed in patients with increased levels of circulating elastase. Images PMID:3005363

  18. Biochemical and structural analysis of the interaction between β-amyloid and fibrinogen.

    PubMed

    Zamolodchikov, Daria; Berk-Rauch, Hanna E; Oren, Deena A; Stor, Daniel S; Singh, Pradeep K; Kawasaki, Masanori; Aso, Kazuyoshi; Strickland, Sidney; Ahn, Hyung Jin

    2016-08-25

    The majority of patients with Alzheimer disease (AD) suffer from impaired cerebral circulation. Accumulating evidence suggests that fibrinogen, the main protein component of blood clots, plays an important role in this circulatory dysfunction in AD. Fibrinogen interacts with β-amyloid (Aβ), forming plasmin-resistant abnormal blood clots, and increased fibrin deposition is found in the brains of AD patients and mouse models. In this study, we investigated the biochemical and structural details of the Aβ-fibrinogen interaction. We identified the central region of Aβ42 as the most critical region for the interaction, which can be inhibited by specific antibodies against the central region of Aβ and by naturally occurring p3 peptides, Aβ17-40 and Aβ17-42. X-ray crystallographic analysis revealed that Aβ42 binding to fragment D of fibrinogen induced a structural change in the C-terminal region of the fibrinogen β-chain (β384-393). Furthermore, we identified an additional Aβ-binding site within the αC region of fibrinogen. Aβ binding to this αC region blocked plasmin-mediated fibrin cleavage at this site, resulting in the generation of increased levels of a plasmin-resistant fibrin degradation fragment. Overall, our study elucidates the Aβ-fibrinogen interaction and clarifies the mechanism by which Aβ-fibrinogen binding delays fibrinolysis by plasmin. These results may facilitate the development of effective therapeutics against the Aβ-fibrinogen interaction to treat cerebrovascular abnormalities in AD. PMID:27389717

  19. Behaviour of 125I-fibrinogen and 131I-albumin in experimental galactosamine-induced hepatitis.

    PubMed Central

    Mahn, I; Merkel, H; Sattler, E L; Müller-Berghaus, G

    1977-01-01

    The turnover of 125I-labelled fibrinogen and 131I-labelled albumin was studied in the course of galactosamine-induced hepatitis in rabbits. In addition to galactosamine, some animals were treated with epsilon-aminocaproic acid (EACA) to inhibit the activation of the fibrinolytic system. The infusion of galactosamine and EACA caused generation of fibrin-rich microclots in the renal glomerular capillaries in seven out of 12 rabbits. Correspondingly, the incorporation of 125I-radioactivity into liver, spleen, and kidneys was pronounced in galactosamine- and EACA-treated rabbits compared with control animals treated with EACA. An acceleration of the 125I-fibrinogen elimination from the plasma was observed between eight and 12 hours after the start of the galactosamine infusion. The administration of heparin in addition to galactosamine and EACA prevented the occurrence of intravascular coagulation, but shortened the survival times of the animals because of bleeding into visceral organs. The elimination of 131I-albumin in plasma as well as the distribution of 131I-radioactivity in organs were similar in all the rabbits independent of the treatment with galactosamine, EACA, or heparin. The experiments indicate that, in addition to diminished synthesis of coagulation factors, disseminated intravascular coagulation is involved in galactosamine-induced hepatitis and contributes to the haemostatic disorder. PMID:873336

  20. Utilisation of Quartz Crystal Microbalance Sensors with Dissipation (QCM-D) for a Clauss Fibrinogen Assay in Comparison with Common Coagulation Reference Methods

    PubMed Central

    Oberfrank, Stephanie; Drechsel, Hartmut; Sinn, Stefan; Northoff, Hinnak; Gehring, Frank K.

    2016-01-01

    The determination of fibrinogen levels is one of the most important coagulation measurements in medicine. It plays a crucial part in diagnostic and therapeutic decisions, often associated with time-critical conditions. The commonly used measurement is the Clauss fibrinogen assay (CFA) where plasma is activated by thrombin reagent and which is conducted by mechanical/turbidimetric devices. As quartz crystal microbalance sensors with dissipation (QCM-D) based devices have a small footprint, can be operated easily and allow measurements independently from sample transportation time, laboratory location, availability and opening hours, they offer a great opportunity to complement laboratory CFA measurements. Therefore, the objective of the work was to (1) transfer the CFA to the QCM-D method; (2) develop an easy, time- and cost-effective procedure and (3) compare the results with references. Different sensor coatings (donor’s own plasma; gold surface) and different QCM-D parameters (frequency signal shift; its calculated turning point; dissipation signal shift) were sampled. The results demonstrate the suitability for a QCM-D-based CFA in physiological fibrinogen ranges. Results were obtained in less than 1 min and in very good agreement with a standardized reference (Merlin coagulometer). The results provide a good basis for further investigation and pave the way to a possible application of QCM-D in clinical and non-clinical routine in the medical field. PMID:26927107

  1. Combined single cell AFM manipulation and TIRFM for probing the molecular stability of multilayer fibrinogen matrices

    PubMed Central

    Christenson, W.; Yermolenko, I.; Plochberger, B.; Camacho-Alanis, F.; Ros, A.; Ugarova, T.P.; Ros, R.

    2014-01-01

    Adsorption of fibrinogen on various surfaces produces a nanoscale multilayer matrix, which strongly reduces the adhesion of platelets and leukocytes with implications for hemostasis and blood compatibility of biomaterials. The nonadhesive properties of fibrinogen matrices are based on their extensibility, ensuing the inability to transduce strong mechanical forces via cellular integrins and resulting in weak intracellular signaling. In addition, reduced cell adhesion may arise from the weaker associations between fibrinogen molecules in the superficial layers of the matrix. Such reduced stability would allow integrins to pull fibrinogen molecules out of the matrix with comparable or smaller forces than required to break integrin–fibrinogen bonds. To examine this possibility, we developed a method based on the combination of total internal reflection fluorescence microscopy, single cell manipulation with an atomic force microscope and microcontact printing to study the transfer of fibrinogen molecules out of a matrix onto cells. We calculated the average fluorescence intensities per pixel for wild-type HEK 293 (HEK WT) and HEK 293 cells expressing leukocyte integrin Mac-1 (HEK Mac-1) before and after contact with multilayered matrices of fluorescently labeled fibrinogen. For contact times of 500 s, HEK Mac-1 cells show a median increase of 57% of the fluorescence intensity compared to 6% for HEKWT cells. The results suggest that the integrin Mac-1-fibrinogen interactions are stronger than the intermolecular fibrinogen interactions in the superficial layer of the matrix. The low mechanical stability of the multilayer fibrinogen surface may contribute to the reduced cell adhesive properties of fibrinogen-coated substrates. We anticipate that the described method can be applied to various cell types to examine their integrin-mediated adhesion to the extracellular matrices with a variable protein composition. PMID:24239757

  2. Relationship between fibrinopeptide A and fibrinogen/fibrin fragment E in thromboembolism, DIC and various non-thromboembolic diseases.

    PubMed

    Mombelli, G; Monotti, R; Haeberli, A; Straub, P W

    1987-08-01

    Increased fibrinopeptide A (FPA) levels have been reported in various non-thrombotic disorders, including cancer, acute myocardial infarction, liver cirrhosis and collagen vascular diseases. To investigate the significance of these findings, the present study combined the radioimmunoassay of FPA with that of fibrinogen/fibrin degradation fragment E (FgE) in the aforementioned disorders and compared the results with those observed in healthy subjects as well as in patients with thromboembolism and overt disseminated intravascular coagulation (DIC). Mean FPA and FgE in malignancy were 6.3 and 305 ng/ml, in myocardial infarction 5.6 and 98 ng/ml, in liver cirrhosis 2.7 and 132 ng/ml and in collagen vascular diseases 5.6 and 142 ng/ml. All these values were significantly higher than in healthy controls (mean FPA 1.6 ng/ml, mean FgE 49 ng/ml) but significantly lower than in thromboembolism (mean FPA 10.7 ng/ml, mean FgE 639 ng/ml). and DIC (mean FPA 22.0 ng/ml, mean FgE 1041 ng/ml). The overall correlation between FPA and FgE was highly significant. However, different disorders showed peculiar patterns in FPA, FgE and fibrinogen levels. In malignancy, a definite increase of FPA, FgE and plasma fibrinogen levels was observed. This finding probably indicates a compensated state of (intra- or extravascular) fibrin formation and lysis. Acute myocardial infarction was characterized by a high FPA to FgE ratio, which is interpreted to reflect acute thrombin generation and fibrin formation. FPA in cirrhosis was only marginally elevated with most single values within the normal range, indicating that intravascular coagulation was infrequent and unimportant in quantitative terms. PMID:3672428

  3. 21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Fibrinogen/fibrin degradation products assay. 864.7320 Section 864.7320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7320 Fibrinogen/fibrin degradation...

  4. 21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fibrinogen/fibrin degradation products assay. 864.7320 Section 864.7320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7320 Fibrinogen/fibrin degradation...

  5. C1q component of complement binds to fibrinogen and fibrin

    SciTech Connect

    Entwistle, R.A.; Furcht, L.T.

    1988-01-12

    The interaction of complement component C1q with fibrinogen and fibrin was studied by using a solid-phase direct binding assay. Scatchard analysis of radioiodinated fibrinogen binding to C1q indicated at least two high-affinity binding constants (Kd) calculated as 8.5 and 120 nM. In contrast, binding of radioiodinated fibrin to C1q showed only a single class of binding sites with a calculated Kd of 600 nM. Fibrinogen-C1q binding was shown to decrease as a function of increasing salt concentrations, indicating either the presence of charged amino acids in the binding sites or an ionic strength induced conformational dependency of the binding. In direct binding studies using isolated fragments of C1q, both the collagen-like domain of C1q and the globular domains of C1q were shown to bind fibrinogen, indicating at least one binding site for fibrinogen is located in each of the major domains of C1q. Addition of the thrombin-generated peptides of fibrinogen, fibrinopeptides A and B, enhanced C1q-fibrinogen binding, again indicating a complex binding interaction. These results indicate that C1q and fibrinogen are capable of high-affinity interactions that may serve to sequester these complexes in areas of tumors, immune complex deposition, or wounds.

  6. Binding of Efb from Staphylococcus aureus to fibrinogen blocks neutrophil adherence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In addition to its pivotal role in hemostasis, fibrinogen (Fg) and provisional fibrin matrices play important roles in inflammation and regulate innate immune responses by interacting with leukocytes. Efb (the extracellular fibrinogen-binding protein) is a secreted Staphylococcus aureus protein that...

  7. Development of Ga-67 labeled DFO-DAS-fibrinogen conjugate as a thrombus imaging agent.

    PubMed

    Yamaoka, S

    1987-01-01

    A cluster method developed for labeling large molecular proteins with radioactive metal was applied for 67Ga-labeled fibrinogen. A large number of deferoxamine (DFO) was introduced to human fibrinogen using dialdehyde strarch (DAS) as a spacer-functional polymer. The synthesized DFO-DAS-fibrinogen mentioned above was easily labeled with GaCl3 (67Ga) solution (2 mCi/5 mg). The basic investigations found that 67Ga-DFO-DAS-fibrinogen was applicable to the diagnosis of thrombus, and clinical trials were carried out under the physician-sponsored IND. In our further investigation, improvement of the 67Ga-DFO-DAS-fibrinogen reagent was attempted to obtain high specific radioactivity. This was accomplished with the more familiar 67Ga citrate. From the results of a series of experiments, 67Ga-DFO-DAS-fibrinogen of a new composition labeled using 67Ga citrate with high specific radioactivity (2 mCi/3 mg) was prepared, and both reagents were evaluated as thrombus imaging agents from the chemical and biological aspects. The labeling efficiency and clottability of both 67Ga-DFO-DAS-fibrinogen conjugates were satisfactorily high, more than 95% and 80%, respectively. The biodistribution in rats showed that both 67Ga-DFO-DAS-fibrinogen conjugates were essentially the same. These results suggest that there are no significant differences between reagents. At present, the improved reagents are being supplied for the second clinical trials under physician-sponsored IND. PMID:3438481

  8. A study on human serum albumin influence on glycation of fibrinogen

    SciTech Connect

    Kielmas, Martyna; Szewczuk, Zbigniew; Stefanowicz, Piotr

    2013-09-13

    Highlights: •The glycation of fibrinogen was investigated by isotopic labeling method. •The potential glycation sites in fibrinogen were identified. •Human serum albumin (HSA) inhibits the glycation of fibrinogen. •The effect of HSA on fibrinogen glycation is sequence-dependent. -- Abstract: Although in vivo glycation proceeds in complex mixture of proteins, previous studies did not take in consideration the influence of protein–protein interaction on Maillard reaction. The aim of our study was to test the influence of human serum albumin (HSA) on glycation of fibrinogen. The isotopic labeling using [{sup 13}C{sub 6}] glucose combined with LC-MS were applied as tool for identification possible glycation sites in fibrinogen and for evaluation the effect of HSA on the glycation level of selected amino acids in fibrinogen. The obtained data indicate that the addition of HSA protects the fibrinogen from glycation. The level of glycation in presence of HSA is reduced by 30–60% and depends on the location of glycated residue in sequence of protein.

  9. Fibrinogen adsorption mechanisms at the gold substrate revealed by QCM-D measurements and RSA modeling.

    PubMed

    Kubiak, Katarzyna; Adamczyk, Zbigniew; Cieśla, Michał

    2016-03-01

    Adsorption kinetics of fibrinogen at a gold substrate at various pHs was thoroughly studied using the QCM-D method. The experimental were interpreted in terms of theoretical calculations performed according to the random sequential adsorption model (RSA). In this way, the hydration functions and water factors of fibrinogen monolayers were quantitatively evaluated at various pHs. It was revealed that for the lower range of fibrinogen coverage the hydration function were considerably lower than previously obtained for the silica sensor [33]. The lower hydration of fibrinogen monolayers on the gold sensor was attributed to its higher roughness. However, for higher fibrinogen coverage the hydration functions for both sensors became identical exhibiting an universal behavior. By using the hydration functions, the fibrinogen adsorption/desorption runs derived from QCM-D measurements were converted to the Γd vs. the time relationships. This allowed to precisely determine the maximum coverage that varied between 1.6mgm(-2) at pH 3.5 and 4.5mgm(-2) at pH 7.4 (for ionic strength of 0.15M). These results agree with theoretical eRSA modeling and previous experimental data derived by using ellipsometry, OWLS and TIRF. Various fibrinogen adsorption mechanisms were revealed by exploiting the maximum coverage data. These results allow one to develop a method for preparing fibrinogen monolayers of well-controlled coverage and molecule orientation. PMID:26705826

  10. Introduction of an algorithm for ROTEM-guided fibrinogen concentrate administration in major obstetric haemorrhage.

    PubMed

    Mallaiah, S; Barclay, P; Harrod, I; Chevannes, C; Bhalla, A

    2015-02-01

    We compared blood component requirements during major obstetric haemorrhage, following the introduction of fibrinogen concentrate. A prospective study of transfusion requirements and patient outcomes was performed for 12 months to evaluate the major obstetric haemorrhage pathway using shock packs (Shock Pack phase). The study was repeated after the pathway was amended to include fibrinogen concentrate (Fibrinogen phase). The median (IQR [range]) number of blood components given was 8.0 (3.0-14.5 [0-32]) during the Shock Pack phase, and 3.0 (2.0-5.0 [0-26]) during the Fibrinogen phase (p = 0.0004). The median (IQR [range]) quantity of fibrinogen administered was significantly greater in the Shock Pack phase, 3.2 (0-7.1 [0-20.4]) g, than in the Fibrinogen phase, 0 (0-3.0 [0-12.4]) g, p = 0.0005. Four (9.5%) of 42 patients in the Shock Pack phase developed transfusion associated circulatory overload compared with none of 51 patients in the Fibrinogen phase (p = 0.038). Fibrinogen concentrate allows prompt correction of coagulation deficits associated with major obstetric haemorrhage, reducing the requirement for blood component therapy and the attendant risks of complications. PMID:25289791

  11. Tigecycline Treatment Causes a Decrease in Fibrinogen Levels

    PubMed Central

    Zhang, Qian; Zhou, Suming

    2014-01-01

    The objective of this study was to assess the impact of tigecycline treatment on coagulation parameters, specifically fibrinogen, in patients with severe infections. We examined 20 cases of tigecycline-treated patients with severe infections, including hospital-acquired pneumonia, complicated intra-abdominal infections, complicated skin and soft tissue infections, and bloodstream infections. We monitored the relative markers of coagulation and renal and liver function before, during, and after treatment. Fibrinogen (FIB) levels decreased significantly after the use of tigecycline and normalized after the cessation of treatment. FIB levels significantly decreased in the patients treated with the recommended dose or a higher treatment dose. The FIB levels decreased more in the higher-treatment-dose group. There was no difference in the decrease in FIB levels or the FIB level recovery by age. Prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT) were prolonged after tigecycline use. The TT decreased after the cessation of treatment, and the PT and APTT also decreased but not to a significant level. There was no change in platelet, alanine aminotransferase (ALT), or creatinine (Cr) levels associated with treatment. The use of tigecycline was associated with decreased FIB levels, which returned to normal after the cessation of treatment. A high-dose treatment group showed greater decreases in FIB levels than did patients treated with the recommended dose. The decline in FIB was not related to patient age. The use of tigecycline was associated with prolonged PT, APTT, and TT. PMID:25547356

  12. Bipartite mRNA for chicken alpha-fibrinogen potentially encodes an amino acid sequence homologous to beta- and gamma-fibrinogens.

    PubMed Central

    Weissbach, L; Grieninger, G

    1990-01-01

    Overlapping cDNAs derived from the chicken alpha-fibrinogen mRNA have been sequenced, beginning from within the coding region for the signal peptide of this subunit and terminating within the poly(A) extension. The predicted size of chicken alpha-fibrinogen is 54,187 daltons, which is the smallest of any alpha chain reported; the oligopeptide repeats that characterize the central regions of the other alpha subunits were conspicuously absent. A further unexpected finding was the presence on the mRNA of a separate, long open reading frame (752 nucleotides), beginning 312 nucleotides downstream from the alpha-fibrinogen coding sequence and containing intron-like features near its 5' end. The protein sequence predicted from this second open reading frame lacks an initiating methionine but is homologous to the C-terminal regions of all known beta- and gamma-fibrinogens as well as the C termini of two nonfibrinogen proteins: cytotactin (tenascin), an extracellular matrix protein, and pT49, a putative protein specific to cytotoxic T cells. The intron-like features of the second open reading frame immediately precede the region of common homology, and the beginnings of the corresponding homologous segments in the beta- and gamma-fibrinogen sequences are marked by aligned intron positions. Based on these findings, it is proposed that fibrinogen gene evolution included a fusion of two distinct ancestral genes. PMID:2367530

  13. Fibrinogen Is at the Interface of Host Defense and Pathogen Virulence in Staphylococcus aureus Infection.

    PubMed

    Ko, Ya-Ping; Flick, Matthew J

    2016-06-01

    Fibrinogen not only plays a pivotal role in hemostasis but also serves key roles in antimicrobial host defense. As a rapidly assembled provisional matrix protein, fibrin(ogen) can function as an early line of host protection by limiting bacterial growth, suppressing dissemination of microbes to distant sites, and mediating host bacterial killing. Fibrinogen-mediated host antimicrobial activity occurs predominantly through two general mechanisms, namely, fibrin matrices functioning as a protective barrier and fibrin(ogen) directly or indirectly driving host protective immune function. The potential of fibrin to limit bacterial infection and disease has been countered by numerous bacterial species evolving and maintaining virulence factors that engage hemostatic system components within vertebrate hosts. Bacterial factors have been isolated that simply bind fibrinogen or fibrin, promote fibrin polymer formation, or promote fibrin dissolution. Staphylococcus aureus is an opportunistic gram-positive bacterium, the causative agent of a wide range of human infectious diseases, and a prime example of a pathogen exquisitely sensitive to host fibrinogen. Indeed, current data suggest fibrinogen serves as a context-dependent determinant of host defense or pathogen virulence in Staphylococcus infection whose ultimate contribution is dictated by the expression of S. aureus virulence factors, the path of infection, and the tissue microenvironment. PMID:27056151

  14. The Primary Role of Fibrinogen-Related Proteins in Invertebrates Is Defense, Not Coagulation

    PubMed Central

    Hanington, Patrick C.; Zhang, Si-Ming

    2010-01-01

    In vertebrates, the conversion of fibrinogen into fibrin is an essential process that underlies the establishment of the supporting protein framework required for coagulation. In invertebrates, fibrinogen-domain-containing proteins play a role in the defense response generated against pathogens; however, they do not function in coagulation, suggesting that this role has been recently acquired. Molecules containing fibrinogen motifs have been identified in numerous invertebrate organisms, and most of these molecules known to date have been linked to defense. Moreover, recent genome projects of invertebrate animals have revealed surprisingly high numbers of fibrinogen-like loci in their genomes, suggesting important and perhaps diverse functions of fibrinogen-like proteins in invertebrates. The ancestral role of molecules containing fibrinogen-related domains (FReDs) with immunity is the focus of this review, with emphasis on specific FReDs called fibrinogen-related proteins (FREPs) identified from the schistosome-transmitting mollusc Biomphalaria glabrata. Herein, we outline the range of invertebrate organisms FREPs can be found in, and detail the roles these molecules play in defense and protection against infection. PMID:21063081

  15. Dissociation of bimolecular αIIbβ3-fibrinogen complex under a constant tensile force.

    PubMed

    Litvinov, Rustem I; Barsegov, Valeri; Schissler, Andrew J; Fisher, Andrew R; Bennett, Joel S; Weisel, John W; Shuman, Henry

    2011-01-01

    The regulated ability of integrin αIIbβ3 to bind fibrinogen plays a crucial role in platelet aggregation, adhesion, and hemostasis. Employing an optical-trap-based electronic force clamp, we studied the thermodynamics and kinetics of αIIbβ3-fibrinogen bond formation and dissociation under constant unbinding forces, mimicking the forces of physiologic blood shear on a thrombus. The distribution of bond lifetimes was bimodal, indicating that the αIIbβ3-fibrinogen complex exists in two bound states with different mechanical stability. The αIIbβ3 antagonist, abciximab, inhibited binding without affecting the unbinding kinetics, whereas Mn²(+) biased the αIIbβ3-fibrinogen complex to the strong bound state with reduced off-rate. The average bond lifetimes decreased exponentially with increasing pulling force from ∼5 pN to 50 pN, suggesting that in this force range the αIIbβ3-fibrinogen interactions are classical slip bonds. We found no evidence for catch bonds, which is consistent with the known lack of shear-enhanced platelet adhesion on fibrinogen-coated surfaces. Taken together, these data provide important quantitative and qualitative characteristics of αIIbβ3-fibrinogen binding and unbinding that underlie the dynamics of platelet adhesion and aggregation in blood flow. PMID:21190668

  16. Streptococcal M1 protein constructs a pathological host fibrinogen network

    PubMed Central

    Macheboeuf, Pauline; Buffalo, Cosmo; Fu, Chi-yu; Zinkernagel, Annelies S.; Cole, Jason N.; Johnson, John E.; Nizet, Victor; Ghosh, Partho

    2012-01-01

    M1 protein, a major virulence factor of the leading invasive strain of group A Streptococcus, is sufficient to induce toxic shock-like vascular leakage and tissue injury. These events are triggered by the formation of a complex between M1 and fibrinogen (Fg) that, unlike M1 or Fg alone, leads to neutrophil activation. Here we provide a structural explanation for the pathological properties of the M1-Fg complex. A conformationally dynamic coiled-coil dimer of M1 was found to organize four Fg molecules into a specific cross-like pattern. This pattern supported the construction of a supramolecular network that was required for neutrophil activation but was distinct from a fibrin clot. Disruption of this network into other supramolecular assemblies was not tolerated. These results have bearing on the pathophysiology of streptococcal toxic shock. PMID:21475196

  17. [Nerve anastomoses. Sutures or fibrinogenic glue? Preliminary results].

    PubMed

    Boedts, D; Bouckaert, J I

    1984-01-01

    A comparative animal experiment was set up between two nerve anastomosis techniques, one by sealing nerve ends with a fibrinogen-thrombine glue and the other by classical perineural suturing. It was concluded that glueing nerve ends, from the surgical-technical point of view is a better method than suturing. It is an easy, time-sparing method which allows excellent coaptation of the severed nerves with minimal iatrogenic trauma. On the long run however some questions remain. There is the problem of induced fibrosis by using high doses of aprotinine and factor XIII at the site of the nerve junctions and on the other hand the influence of fibrinolysis in traumatized tissues, with early decrease of tensile strength at the junctions before nerve healing. So glued nerve ends should be completely free of tension, protected against secondary shearing forces, and also immobilization of the region is required. PMID:6385609

  18. 5-fluorouracil loaded fibrinogen nanoparticles for cancer drug delivery applications.

    PubMed

    Rejinold, N Sanoj; Muthunarayanan, M; Chennazhi, K P; Nair, S V; Jayakumar, R

    2011-01-01

    In this study, 5-flurouracil loaded fibrinogen nanoparticles (5-FU-FNPs) were prepared by two step coacervation method using calcium chloride as cross-linker. The prepared nanoparticles were characterized using DLS, SEM, AFM, FT-IR, TG/DTA and XRD studies. Particle size of 5-FU-FNPs was found to be 150-200 nm. The loading efficiency (LE) and in vitro drug release was studied using UV spectrophotometer. The LE of FNPs was found to be ∼90%. The cytotoxicity studies showed 5-FU-FNPs were toxic to MCF7, PC3 and KB cells while they are comparatively non toxic to L929 cells. Cellular uptake of Rhodamine 123 conjugated 5-FU-FNPs was also studied. Cell uptake studies demonstrated that the nanoparticles are inside the cells. These results indicated that FNPs could be useful for cancer drug delivery. PMID:20951162

  19. Influence of Ficoll on urea induced denaturation of fibrinogen

    NASA Astrophysics Data System (ADS)

    Sankaranarayanan, Kamatchi; Meenakshisundaram, N.

    2016-03-01

    Ficoll is a neutral, highly branched polymer used as a molecular crowder in the study of proteins. Ficoll is also part of Ficoll-Paque used in biology laboratories to separate blood to its components (erythrocytes, leukocytes etc.,). Role of Ficoll in the urea induced denaturation of protein Fibrinogen (Fg) has been analyzed using fluorescence, circular dichroism, molecular docking and interfacial studies. Fluorescence studies show that Ficoll prevents quenching of Fg in the presence of urea. From the circular dichroism spectra, Fg shows conformational transition to random coil with urea of 6 M concentration. Ficoll helps to shift this denaturation concentration to 8 M and thus constraints by shielding Fg during the process. Molecular docking studies indicate that Ficoll interacts favorably with the protein than urea. The surface tension and shear viscosity analysis shows clearly that the protein is shielded by Ficoll.

  20. Fibrinogen-induced increased pial venular permeability in mice

    PubMed Central

    Muradashvili, Nino; Qipshidze, Natia; Munjal, Charu; Givvimani, Srikanth; Benton, Richard L; Roberts, Andrew M; Tyagi, Suresh C; Lominadze, David

    2012-01-01

    Elevated blood level of Fibrinogen (Fg) is commonly associated with vascular dysfunction. We tested the hypothesis that at pathologically high levels, Fg increases cerebrovascular permeability by activating matrix metalloproteinases (MMPs). Fibrinogen (4 mg/mL blood concentration) or equal volume of phosphate-buffered saline (PBS) was infused into male wild-type (WT; C57BL/6J) or MMP-9 gene knockout (MMP9−/−) mice. Pial venular leakage of fluorescein isothiocyanate-bovine serum albumin to Fg or PBS alone and to topically applied histamine (10−5 mol/L) were assessed. Intravital fluorescence microscopy and image analysis were used to assess cerebrovascular protein leakage. Pial venular macromolecular leakage increased more after Fg infusion than after infusion of PBS in both (WT and MMP9−/−) mice but was more pronounced in WT compared with MMP9−/− mice. Expression of vascular endothelial cadherin (VE-cadherin) was less and plasmalemmal vesicle-associated protein-1 (PV-1) was greater in Fg-infused than in PBS-infused both mice groups. However, in MMP9−/− mice, VE-cadherin expression was greater and PV-1 expression was less than in WT mice. These data indicate that at higher levels, Fg compromises microvascular integrity through activation of MMP-9 and downregulation of VE-cadherin and upregulation of PV-1. Our results suggest that elevated blood level of Fg could have a significant role in cerebrovascular dysfunction and remodeling. PMID:21989482

  1. Bacteriophage lysin mediates the binding of streptococcus mitis to human platelets through interaction with fibrinogen.

    PubMed

    Seo, Ho Seong; Xiong, Yan Q; Mitchell, Jennifer; Seepersaud, Ravin; Bayer, Arnold S; Sullam, Paul M

    2010-01-01

    The binding of bacteria to human platelets is a likely central mechanism in the pathogenesis of infective endocarditis. We have previously found that platelet binding by Streptococcus mitis SF100 is mediated by surface components encoded by a lysogenic bacteriophage, SM1. We now demonstrate that SM1-encoded lysin contributes to platelet binding via its direct interaction with fibrinogen. Far Western blotting of platelets revealed that fibrinogen was the major membrane-associated protein bound by lysin. Analysis of lysin binding with purified fibrinogen in vitro confirmed that these proteins could bind directly, and that this interaction was both saturable and inhibitable. Lysin bound both the Aalpha and Bbeta chains of fibrinogen, but not the gamma subunit. Binding of lysin to the Bbeta chain was further localized to a region within the fibrinogen D fragment. Disruption of the SF100 lysin gene resulted in an 83+/-3.1% reduction (mean +/- SD) in binding to immobilized fibrinogen by this mutant strain (PS1006). Preincubation of this isogenic mutant with purified lysin restored fibrinogen binding to wild type levels. When tested in a co-infection model of endocarditis, loss of lysin expression resulted in a significant reduction in virulence, as measured by achievable bacterial densities (CFU/g) within vegetations, kidneys, and spleens. These results indicate that bacteriophage-encoded lysin is a multifunctional protein, representing a new class of fibrinogen-binding proteins. Lysin appears to be cell wall-associated through its interaction with choline. Once on the bacterial surface, lysin can bind fibrinogen directly, which appears to be an important interaction for the pathogenesis of endocarditis. PMID:20714354

  2. [Effect of fibrinogen on corrosion behavior of stainless steel in artificial blood solution].

    PubMed

    Guo, L; Liang, C; Guo, H; Chen, W

    2001-12-01

    The effect of fibrinogen on corrosion behavior of SUS316L and SUS317L stainless steel in artificial blood PBS solution has been investigated with electrochemical technology. The results showed that the corrosion potential (Ec) of stainless steel shifted negatively, the passivated current (ip) became less and the pitting corrosion potential (Eb) shifted negatively with the existence of fibrinogen in PBS. These indicate that samples become more sensitive to corrosion under this circumstance. SEM pictures demonstrated that stainless steel adsorbed fibrinogen on its surface. PMID:11791309

  3. Fibrinogen-like protein 1, a hepatocyte derived protein is an acute phase reactant

    SciTech Connect

    Liu Zhilin; Ukomadu, Chinweike

    2008-01-25

    Fibrinogen-like protein 1 (FGL1) is a hepatocyte derived protein that is upregulated in regenerating rodent livers following partial hepatectomy. It has been implicated as a mitogen for liver cell proliferation. In this study, we show that recombinant human IL-6 induces FGL1 expression in Hep G2 cells in a pattern similar to those of acute phase reactants. Following induction of acute inflammation in rats by subcutaneous injection of turpentine oil, serum FGL1 levels are also enhanced. Although, a recent report suggests that FGL1 associates almost exclusively with the fibrin matrix, we report here that approximately 20% of the total plasma FGL1 remains free. The enhancement of FGL1 levels in vitro by IL-6 and its induction after turpentine oil injection suggest that it is an acute phase reactant. Its presence in bound and free forms in the blood also implies biological roles that extend beyond the proposed autocrine effect it has on hepatocytes during regeneration.

  4. Biocompatible and biodegradable fibrinogen microspheres for tumor-targeted doxorubicin delivery

    PubMed Central

    Joo, Jae Yeon; Park, Gil Yong; An, Seong Soo A

    2015-01-01

    In the development of effective drug delivery carriers, many researchers have focused on the usage of nontoxic and biocompatible materials and surface modification with targeting molecules for tumor-specific drug delivery. Fibrinogen (Fbg), an abundant glycoprotein in plasma, could be a potential candidate for developing drug carriers because of its biocompatibility and tumor-targeting property via arginine–glycine–aspartate (RGD) peptide sequences. Doxorubicin (DOX), a chemotherapeutic agent, was covalently conjugated to Fbg, and the microspheres were prepared. Acid-labile and non-cleavable linkers were used for the conjugation of DOX to Fbg, resulting in an acid-triggered drug release under a mild acidic condition and a slow-controlled drug release, respectively. In vitro cytotoxicity tests confirmed low cytotoxicity in normal cells and high antitumor effect toward cancer cells. In addition, it was discovered that a longer linker could make the binding of cells to Fbg drug carriers easier. Therefore, DOX–linker–Fbg microspheres could be a suitable drug carrier for safer and effective drug delivery. PMID:26366073

  5. Characterization of nanobodies binding human fibrinogen selected by E. coli display.

    PubMed

    Salema, Valencio; López-Guajardo, Ana; Gutierrez, Carlos; Mencía, Mario; Fernández, Luis Ángel

    2016-09-20

    Abnormal levels of fibrinogen (Fib) in blood plasma are associated with several pathological conditions and hence methods for its detection in blood and body fluids are essential. Nanobodies (Nbs) or (VHHs) are single domain antibodies derived from camelids with excellent biophysical and antigen-binding properties, showing great promise in diagnostics and therapy. In this work, we select and characterize high affinity Nbs binding human Fib employing an E. coli cell surface display system based on the fusion of an immune library of VHH domains with the β-domain of Intimin. Bacteria displaying high-affinity Nbs against Fib were selected using magnetic cell sorting (MACS). Specific binding of the selected clones to Fib was confirmed by flow cytometry of E. coli bacteria, as well as by enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) with the purified Nbs. E. coli display also provided an excellent estimation of the affinity of the selected Nbs by flow cytometry analysis under equilibrium conditions, with equilibrium constant (KD) values very similar to those obtained by SPR analysis. Finally, pairwise epitope-scouting studies revealed that the selected Nbs bound distinct epitopes on Fib. The selected Nbs are promising diagnostic tools for determination of human Fib levels. PMID:27485813

  6. A novel missense mutation in the FGB g. 3354 T>A (p. Y41N), Fibrinogen Caracas VIII

    PubMed Central

    Marchi, Rita; Rojas, Héctor; Meyer, Michael; Castillo, Oscar; De Sáez Ruiz, Arlette; Weisel, John W.

    2012-01-01

    Summary A novel dysfibrinogenemia with a replacement of Tyr by Asn at Bβ41 has been discovered (fibrinogen Caracas VIII). An asymptomatic 39 year-old male was diagnosed as having dysfibrinogenemia due to a mildly prolonged thrombin time (+ 5.8 sec); his fibrinogen concentration was in the low normal range, both by Clauss and gravimetric determination, 1.9 g/l and 2.1 g/l, respectively. The plasma polymerization process was slightly impaired, characterized by a mildly prolonged lag time and a slightly increased final turbidity. Permeation through the patients’ clots was dramatically increased, with the Darcy constant around 4 times greater than that of the control (22 ± 2 ×10−9 cm2 compared to 6 ± 0.5 ×10−9 cm2 in controls). The plasma fibrin structure of the patient, by scanning electron microscopy, featured a mesh composed of thick fibers (148 ± 50 nm vs. 120 ± 31 nm in controls, p<0.05) and larger pores than those of the control fibrin clot. The viscoelastic properties of the clot from the patient were also altered, as the storage modulus (G′, 310 ± 30) was much lower than in the control (831 ± 111) (p ≤ 0.005). The interaction of the fibrin clot with a monolayer of human microvascular endothelial cells, by confocal laser microscopy, revealed that the patients’ fibrin network had less interaction with the cells. These results demonstrate the significance of the amino terminal end of the β chain of fibrin in the polymerization process and its consequences on the clot organization on the surface of endothelial cells. PMID:21301788

  7. Preparation and biocompatibility of electrospun poly( L-lactide-co-ɛ-caprolactone)/fibrinogen blended nanofibrous scaffolds

    NASA Astrophysics Data System (ADS)

    Fang, Zhengdong; Fu, Weiguo; Dong, Zhihui; Zhang, Xiangman; Gao, Bin; Guo, Daqiao; He, Hongbing; Wang, Yuqi

    2011-02-01

    Electrospun blended nanofibrous scaffolds were fabricated from an synthetic biodegradable polymer (poly(L-lactide-co-ɛ-caprolactone): PLCL; 8% solution) and a natural protein (fibrinogen; 100 mg/ml solution) with different volume ratios. Results showed that the blended scaffolds consisted of nanoscale fibers with mean diameters ranging from 224 to 450 nm. The deposition of the fibrinogen amino groups on the surfaces of the blended scaffolds was confirmed by XPS. The hydrophilicity of the blended scaffolds were improved with the fibrinogen content increasing in the blended system. Cell viability assay and SEM results showed that human umbilical vein endothelial cells (HUVECs) had progressive growth and well spread morphology on the blended scaffolds. This study demonstrated that electrospun PLCL/fibrinogen blended scaffolds have potential application in tissue engineering.

  8. Phosphorylation in vitro of human fibrinogen with casein kinase TS and characterization of phosphorylated sites

    SciTech Connect

    Heldin, P.

    1987-09-01

    Human fibrinogen was phosphorylated by casein kinase TS. The (/sup 32/P)phosphate incorporated varied between 0.5 and 1 mol of phosphate per mole of fibrinogen. The phosphate was localized to Ser523 and Ser590 and serine and threonine residues between amino acids 259 and 268 in the A alpha-chain. In addition, Thr416 and Ser420 were phosphorylated in the gamma'-chain, which is a variant of the gamma-chain, constituting 7-10% of the gamma-chain population. The functional significance of casein kinase TS-induced phosphorylation of fibrinogen remains unknown; however, a slight but consistent increase of the turbidity in a gelation assay was observed for phosphorylated compared to unphosphorylated fibrinogen.

  9. Higher Fibrinogen Levels Predict Progression of Coronary Artery Calcification in Adults with Type 1 Diabetes

    PubMed Central

    Rodrigues, T.C.; Snell-Bergeon, J.K.; Maahs, D.M; Kinney, G.L.; Rewers, M.

    2010-01-01

    Aim To determine whether fibrinogen levels predict independently progression of coronary artery calcification (CAC) in adults with type 1 diabetes. Methods Data from a prospective cohort - the Coronary Artery Calcification in Type 1 Diabetes Study - were evaluated. Fibrinogen levels at baseline were separated into quartiles. CAC was measured twice and averaged at baseline and at follow-up 2.4 ± 0.4 years later. CAC progressors were defined as participants whose square-root transformed CAC volume increased by ≥ 2.53 or development mm of clinical coronary artery disease during the follow-up period. Results Fibrinogen levels were higher in progressors than in non-progressors (276 ± 61 mg/dl versus 259 ± 61 mg/dl, p = 0.0003). CAC progression, adjusted for known cardiovascular risk factors, increased in the highest quartile. Conclusions Higher fibrinogen levels predict CAC progression in type 1 diabetes subjects, independent of standard cardiovascular risk factors. PMID:20079495

  10. Gallium nitrate induces fibrinogen flocculation: an explanation for its hemostatic effect?

    PubMed

    Bauters, A; Holt, D J; Zerbib, P; Rogosnitzky, M

    2013-12-01

    A novel hemostatic effect of gallium nitrate has recently been discovered. Our aim was to perform a preliminary investigation into its mode of action. Thromboelastography® showed no effect on coagulation but pointed instead to changes in fibrinogen concentration. We measured functional fibrinogen in whole blood after addition of gallium nitrate and nitric acid. We found that gallium nitrate induces fibrinogen precipitation in whole blood to a significantly higher degree than solutions of nitric acid alone. This precipitate is not primarily pH driven, and appears to occur via flocculation. This behavior is in line with the generally observed ability of metals to induce fibrinogen precipitation. Further investigation is required into this novel phenomenon. PMID:23959335

  11. Free oscillation rheometry monitoring of haemodilution and hypothermia and correction with fibrinogen and factor XIII concentrates

    PubMed Central

    2013-01-01

    Background Haemodilution and hypothermia induce coagulopathy separately, but their combined effect on coagulation has not been widely studied. Fibrinogen concentrate can correct dilutional coagulopathy and has an additional effect when combined with factor XIII concentrate. However, their effect on dilutional coagulopathy concomitant with hypothermia has not been studied previously. Free oscillation rheometry – FOR (Reorox®) – is a novel viscoelastic haemostatic assay that has not been studied in this context before. Methods Blood from 10 healthy volunteers was diluted by 33% with hydroxyethyl starch or Ringer’s acetate solutions. Effects of fibrinogen added in vitro with and without factor XIII were studied at 33°C and 37°C. Coagulation velocity (coagulation time) and clot strength (elasticity) were assessed with FOR. Coagulation was initiated in vitro with thromboplastin alone, or thromboplastin plus a platelet inhibitor. Results Hydroxyethyl starch increased the coagulation time and decreased clot strength significantly more than Ringer’s acetate solution, both in the presence and absence of a platelet inhibitor. There was a significant interaction between haemodilution with hydroxyethyl starch and hypothermia, resulting in increased coagulation time. After addition of fibrinogen, coagulation time shortened and elasticity increased, with the exception of fibrinogen-dependent clot strength (i.e., elasticity in the presence of a platelet inhibitor) after hydroxyethyl starch haemodilution. Factor XIII had an additional effect with fibrinogen on fibrinogen-dependent clot strength in blood diluted with Ringer’s acetate solution. Hypothermia did not influence any of the coagulation factor effects. Conclusions Both haemodilution and mild hypothermia impaired coagulation. Coagulopathy was more pronounced after haemodilution with hydroxyethyl starch than with Ringer’s acetate. Addition of fibrinogen with factor XIII was unable to reverse hydroxyethyl

  12. Characterization of the fibrinogen binding domain of bacteriophage lysin from Streptococcus mitis.

    PubMed

    Seo, Ho Seong; Sullam, Paul M

    2011-09-01

    The binding of bacteria to human platelets is a likely central mechanism in the pathogenesis of infective endocarditis. Platelet binding by Streptococcus mitis SF100 is mediated in part by a lysin encoded by the lysogenic bacteriophage SM1. In addition to its role in the phage life cycle, lysin mediates the binding of S. mitis to human platelets via its interaction with fibrinogen on the platelet surface. To better define the region of lysin mediating fibrinogen binding, we tested a series of purified lysin truncation variants for their abilities to bind this protein. These studies revealed that the fibrinogen binding domain of lysin is contained within the region spanned by amino acid residues 102 to 198 (lysin(102-198)). This region has no sequence homology to other known fibrinogen binding proteins. Lysin(102-198) bound fibrinogen comparably to full-length lysin and with the same selectivity for the fibrinogen Aα and Bβ chains. Lysin(102-198) also inhibited the binding in vitro of S. mitis to human fibrinogen and platelets. When assessed by platelet aggregometry, the disruption of the lysin gene in SF100 resulted in a significantly longer time to the onset of aggregation of human platelets than that of the parent strain. The preincubation of platelets with purified lysin(102-198) also delayed the onset of aggregation by SF100. These results indicate that the binding of lysin to fibrinogen is mediated by a specific domain of the phage protein and that this interaction is important for both platelet binding and aggregation by S. mitis. PMID:21690235

  13. Evaluation of the viability of /sup 111/In-abeled DTPA coupled to fibrinogen

    SciTech Connect

    Layne, W.W.; Hnatowich, D.J.; Doherty, P.W.; Childs, R.L.; Lanteigne, D.; Ansell, J.

    1982-07-01

    In earlier work, DTPA has been covalently coupled to albumin via the cyclic anhydride of DTPA. Using fibrinogen, we have studied the effect of such coupling on protein viability by both an in vitro and an in vivo assay. Clotting time remained identical to that of the native protein whether the anhydride-to-protein molar ratio was 1:1 or 5:1. In vivo studies were done in dogs, with human fibrinogen labeled with /sup 125/I and /sup 111/In. Throughout 130 hr, blood clearances for the two tracers agreed whether with 1:1 or 5:1 coupling. In a dog model with a thrombogenic catheter, the clot-to-blood ratios for the two radiotracers agreed within experimental error. Finally, 1:1-coupled canine fibrinogen, labeled with /sup 111/In, was administered to dogs with a catheter in a jugular vein, and scintigrams at 24 hr clearly showed clotting along the length of the catheter. We conclude that fibrinogen, coupled to DTPA, retains its viability, behaving like radioiodinated fibrinogen in vivo, and /sup 111/In labeled fibrinogen looks promising as a clinical diagnostic agent.

  14. Electrospun fibrinogen: feasibility as a tissue engineering scaffold in a rat cell culture model.

    PubMed

    McManus, Michael C; Boland, Eugene D; Simpson, David G; Barnes, Catherine P; Bowlin, Gary L

    2007-05-01

    Fibrinogen has a well-established tissue engineering track record because of its ability to induce improved cellular interaction and scaffold remodeling compared to synthetic scaffolds. While the feasibility of electrospinning fibrinogen scaffolds of submicron diameter fibers and their mechanical properties have been demonstrated, in vitro cellular interaction has not yet been evaluated. The goal of this study was to demonstrate, based on cellular interaction and scaffold remodeling, that electrospun fibrinogen can be used successfully as a tissue engineering scaffold. Electrospun fibrinogen scaffolds were disinfected, seeded with neonatal rat cardiac fibroblasts, and cultured for 2, 7, and 14 days. Cultures were treated to regulate scaffold degradation by either supplementing serum-containing media with aprotinin or crosslinking the scaffolds with glutaraldehyde vapor. Biocompatibility was assessed through a WST-1 cell proliferation assay. Postculture scaffolds were evaluated by scanning electron microscopy and histology. Cell culture demonstrated that fibroblasts readily migrate into and remodel electrospun fibrinogen scaffolds with deposition of native collagen. Supplementation of culture media with different concentrations of aprotinin-modulated scaffold degradation in a predictable fashion, but glutaraldehyde vapor fixation was less reliable. Based on the observed cellular interactions, there is tremendous potential for electrospun fibrinogen as a tissue engineering scaffold. PMID:17120217

  15. Role of Serum Fibrinogen Levels in Patients with Rotator Cuff Tears

    PubMed Central

    Longo, Umile Giuseppe; Petrillo, Stefano; Berton, Alessandra; Spiezia, Filippo; Loppini, Mattia; Maffulli, Nicola; Denaro, Vincenzo

    2014-01-01

    Although rotator cuff (RC) tendinopathy is a frequent pathology of the shoulder, the real understanding of its aetiopathogenesis is still unclear. Several studies showed that RC tendinopathy is more frequent in patients with hyperglycemia, diabetes, obesity, or metabolic syndrome. This paper aims to evaluate the serum concentration of fibrinogen in patients with RC tears. Metabolic disorders have been related to high concentration of serum fibrinogen and the activity of fibrinogen has been proven to be crucial in the development of microvascular damage. Thus, it may produce progression of RC degeneration by reducing the vascular supply of tendons. We report the results of a cross-sectional frequency-matched case-control study comparing the serum concentration of fibrinogen of patients with RC tears with that of a control group of patients without history of RC tears who underwent arthroscopic meniscectomy. We choose to enrol in the control group patients with pathology of the lower limb with a likely mechanic, not metabolic, cause, different from tendon pathology. We found no statistically significant differences in serum concentration of fibrinogen when comparing patients with RC tears and patients who underwent arthroscopic meniscectomy (P = 0.5). Further studies are necessary to clarify the role of fibrinogen in RC disease. PMID:24817887

  16. Comparing the Effects of Lovastatin and Cornus Mas Fruit on Fibrinogen Level in Hypercholesterolemic Rabbits

    PubMed Central

    Asgary, Sedigheh; Rafieian-Kopaei, Mahmoud; Adelnia, Azadeh; Kazemi, Somayeh; Shamsi, Fatemeh

    2010-01-01

    BACKGROUND Atherosclerosis, which is a result of gradual deposition of lipids in the lower part of blood vessel endothelium, is the leading cause of mortality and morbidity around the world. It has been proved that some inflammatory blood markers such as fibrinogen can predict the risk for cardiovascular disease conditions, not only in cardiovascular patients, but also in those who do not have any manifestations of the atherosclerotic development. In this study, the effect of cornus mas l. was evaluated on fibrinogen of hypercholesterolemic rabbits and it was also compared with lovastatin drug. METHODS In this study, 25 New Zealand adult male rabbits were randomly divided into five groups of five. They were treated for 60 days by 5 different diets, namely basic, high cholesterol, regular plus 1 g/kgBW cornus mas L. powder, high cholesterol plus 1 g/kgBW cornus mas L. powder, and high cholesterol plus 10 mg/kgBW lovastatin. At the beginning and at the end of this period, blood samples were collected from the rabbits and their serum fibrinogen levels were measured. RESULTS Cornus mas L. powder and lovastatin significantly decreased fibrinogen levels in comparison with high cholesterol group (P < 0.05). Furthermore cornus mas L. powder could reduce the fibrinogen level more than lovastatin (P < 0.05). CONCLUSION The results indicated that consumption of cornus mas L. might be beneficial in atherosclerotic patients due to its reducing effects on fibrinogen. PMID:22577405

  17. The Internal Dynamics of Fibrinogen and Its Implications for Coagulation and Adsorption

    PubMed Central

    Köhler, Stephan; Schmid, Friederike; Settanni, Giovanni

    2015-01-01

    Fibrinogen is a serum multi-chain protein which, when activated, aggregates to form fibrin, one of the main components of a blood clot. Fibrinolysis controls blood clot dissolution through the action of the enzyme plasmin, which cleaves fibrin at specific locations. Although the main biochemical factors involved in fibrin formation and lysis have been identified, a clear mechanistic picture of how these processes take place is not available yet. This picture would be instrumental, for example, for the design of improved thrombolytic or anti-haemorrhagic strategies, as well as, materials with improved biocompatibility. Here, we present extensive molecular dynamics simulations of fibrinogen which reveal large bending motions centered at a hinge point in the coiled-coil regions of the molecule. This feature, likely conserved across vertebrates according to our analysis, suggests an explanation for the mechanism of exposure to lysis of the plasmin cleavage sites on fibrinogen coiled-coil region. It also explains the conformational variability of fibrinogen observed during its adsorption on inorganic surfaces and it is supposed to play a major role in the determination of the hydrodynamic properties of fibrinogen. In addition the simulations suggest how the dynamics of the D region of fibrinogen may contribute to the allosteric regulation of the blood coagulation cascade through a dynamic coupling between the a- and b-holes, important for fibrin polymerization, and the integrin binding site P1. PMID:26366880

  18. Control of Fibrinogen Assembly by Changing a Polarity of Surfaces

    NASA Astrophysics Data System (ADS)

    Koo, Jaseung; Liu, Ying; Snow, Sara; Rambhia, Pooja; Koga, Tadanori; Rafailovich, Miriam; Galanakis, Dennis

    2009-03-01

    Thrombogenesis causes various problems associated with an interruption in the blood flow (e.g., myocardial and cerebral infarction), and a hindrance to use of blood-contact vascular biomaterials (e.g., hemodialysis and cardiopulmonary bypass) with long-term patency since undesired adsorption of blood components occurs on vessels or biomaterials, such as surface-induced thrombosis. we showed that this clotting procedure can be occurred on hydrophobic polymeric surfaces without thrombin cleavage. However, the fibrinogen fibers were not formed on the polar surface such as spun-cast polymer film with pyridine and phenol groups. We also found that αC domains play an important role in initiation of polymerization on surface. Therefore, molecular association was inhibited on the polar surfaces due to confinement of αC chains on the surfaces. These findings were directly applied to stent surface modification. The commercial stent consist of Co-Cr alloy forms undesired fiber formation. However, PS-r-PVPh (13% phenol) coated stent surfaces completely prevent fiber formation.

  19. Inhibition of thrombin generation in plasma by fibrin formation (Antithrombin I).

    PubMed

    de Bosch, N B; Mosesson, M W; Ruiz-Sáez, A; Echenagucia, M; Rodriguez-Lemoin, A

    2002-08-01

    The adsorption of thrombin to fibrin during clotting defines "Antithrombin I" activity. We confirmed that thrombin generation in afibrinogenemic or in Reptilase defibrinated normal plasma was higher than in normal plasma. Repletion of these fibrinogen-deficient plasmas with fibrinogen 1 (gamma A/gamma A), whose fibrin has two "low affinity" non-substrate thrombin binding sites, resulted in moderately reduced thrombin generation by 29-37%. Repletion with fibrinogen 2 (gamma'/gamma A), which in addition to low affinity thrombin-binding sites in fibrin, has a "high affinity" non-substrate thrombin binding site in the carboxy-terminal region of its gamma' chain, was even more effective and reduced thrombin generation by 57-67%. Adding peptides that compete for thrombin binding to fibrin [S-Hir53-64 (hirugen) or gamma'414-427] caused a transient delay in the onset of otherwise robust thrombin generation, indicating that fibrin formation is necessary for full expression of Antithrombin I activity. Considered together, 1) the increased thrombin generation in afibrinogenemic or fibrinogen-depleted normal plasma that is mitigated by fibrinogen replacement; 2) evidence that prothrombin activation is increased in afibrinogenemia and normalized by fibrinogen replacement; 3) the severe thrombophilia that is associated with defective thrombin-binding in dysfibrinogenemias Naples I and New York I, and 4) the association of afibrinogenemia or hypofibrinogenemia with venous or arterial thromboembolism, indicate that Antithrombin I (fibrin) modulates thromboembolic potential by inhibiting thrombin generation in blood. PMID:12195697

  20. Scanning probe microscopy for the analysis of composite Ti/hydrocarbon plasma polymer thin films

    NASA Astrophysics Data System (ADS)

    Choukourov, A.; Grinevich, A.; Slavinska, D.; Biederman, H.; Saito, N.; Takai, O.

    2008-03-01

    Composite Ti/hydrocarbon plasma polymer films with different Ti concentration were deposited on silicon by dc magnetron sputtering of titanium in an atmosphere of argon and hexane. As measured by Kelvin force microscopy and visco-elastic atomic force microscopy, respectively, surface potential and hardness increase with increasing Ti content. Adhesion force to silicon and to fibrinogen molecules was stronger for the Ti-rich films as evaluated from the AFM force-distance curves. Fibrinogen forms a very soft layer on these composites with part of the protein molecules embedded in the outermost region of the plasma polymer. An increase of the surface charge due to fibrinogen adsorption has been observed and attributed to positively charged αC domains of fibrinogen molecule.

  1. Hydroxyl density affects the interaction of fibrinogen with silica nanoparticles at physiological concentration.

    PubMed

    Marucco, Arianna; Turci, Francesco; O'Neill, Luke; Byrne, Hugh J; Fubini, Bice; Fenoglio, Ivana

    2014-04-01

    An increasing interest in the interaction between blood serum proteins and nanoparticles has emerged over the last years. In fact, this process plays a key role in the biological response to nanoparticles. The behavior of proteins at the biofluid/material interface is driven by the physico-chemical properties of the surface. However, much research is still needed to gain insight into the process at a molecular level. In this study, the effect of silanol density on the interaction of fibrinogen at physiological concentrations with silica nanoparticle/flat surfaces has been studied. Silica nanoparticles and silica wafers were modified and characterized to obtain a set of samples with different silanols density. The interaction with fibrinogen has been studied by evaluating the extent of coverage (bicinchoninic acid assay) and the irreversibility of adsorption (shift of the ζ potential). To clarify the molecular mechanism of fibrinogen/surface interactions, confocal micro-Raman spectroscopy (nanoparticles) and atomic force microscopy (wafers) were used. Finally the effect of fibrinogen on the agglomeration of nanoparticles has been evaluated by Flow Particle Image Analysis. The data reported here show that a minimal variation in the state of the silica surface modifies the adsorption behavior of fibrinogen, which appears mediated by a competition between protein/protein and protein/surface interactions. By comparing the data obtained on nanoparticles and silicon-supported silica layers, we found that hydrophilicity increases the tendency of fibrinogen molecules to interact with the surface rather than with other molecules, thus inhibiting fibrinogen self-assembly. This study contributes to the knowledge of the processes occurring at the surface/biological fluids interface, needed for the design of new biocompatible materials. PMID:24491335

  2. Feeding acutely stimulates fibrinogen synthesis in healthy young and elderly adults.

    PubMed

    Caso, Giuseppe; Mileva, Izolda; Kelly, Patricia; Ahn, Hongshik; Gelato, Marie C; McNurlan, Margaret A

    2009-11-01

    Fibrinogen is a positive acute-phase protein and its hepatic synthesis is enhanced following inflammation and injury. However, it is not clear whether fibrinogen synthesis is also responsive to oral nutrients and whether the response to a meal may be affected by age. Our aim in this study was to investigate the acute effect of oral feeding on fibrinogen synthesis in both young and elderly men and women. Fibrinogen synthesis was determined in 3 separate occasions from the incorporation of l[(2)H(5)]phenylalanine (43 mg/kg body weight) in 8 young (21-35 y) and 8 elderly (>60 y) participants following the ingestion of water (control), a complete liquid meal (15% protein, 30% fat, and 55% carbohydrate), or only the protein component of the meal. The ingestion of the complete meal enhanced fibrinogen fractional synthesis rates (FSR) by 17 +/- 6% in the young and by 38 +/- 10% in the elderly participants compared with the water meal (P < 0.02). A comparable stimulation of FSR occurred with only the protein component of the meal in both young (29 +/- 7%) and elderly participants (41 +/- 9%) compared with the water meal (P < 0.005). Similar results were obtained when fibrinogen synthesis was expressed as absolute synthesis rates (i.e. mg.kg(-1).d(-1)). The results demonstrate that fibrinogen synthesis is acutely stimulated after ingestion of a meal and that this effect can be reproduced by the protein component of the meal alone, both in young and elderly adults. PMID:19759246

  3. Quantitative evaluation of interaction force of fibrinogen at well-defined surfaces with various structures.

    PubMed

    Chen, Weixin; Inoue, Yuuki; Ishihara, Kazuhiko

    2014-01-01

    The effects of functional groups and structures at the surface of biomaterials on protein adsorption were examined using direct interaction force measurements. Three kinds of surface structures were evaluated: polymer brushes, self-assembled monolayers with low molecular weight compounds, and surfaces with conventional polymer coatings. These surfaces had various functional groups including phosphorylcholine (PC) group. The surface characterization demonstrated that surface wettability and flexibility depended on both the structure of the surface and the functional groups at the surface. The interactions of protein with these surfaces were evaluated by a force vs. distance curve using an atomic force microscope (AFM). We used fibrinogen as the protein, and the fibrinogen was immobilized on the surface of the AFM cantilever by a conventional technique. It was observed that the interaction force of fibrinogen was strongly related to surface hydrophobic nature and flexibility. That is, the interaction force increased with the increasing hydrophobic nature of the surface. The relationship between the amount of fibrinogen adsorbed on the surface and the interaction force showed good correlation in the range of fibrinogen adsorption from 0 to 250 ng/cm(2), that is, in a monolayered adsorption region. The interaction force decreased with increasing surface viscoelasticity. The most effective surface for preventing fibrinogen adsorption was the polymer brush surface with phosphorylcholine (PC) groups, that is, poly(2-methacryloyloxyethyl phosphorylcholine) brush. The interaction force of this sample was less than 0.1 nN and the amount of fibrinogen adsorbed on the surface was minimal. It was found that the evaluation of protein adsorption based on the interaction force measurement is useful for low-protein adsorption surfaces. It was demonstrated that an extremely hydrophilic and flexible surface could weaken the protein interactions at the surface, resulting in

  4. Feeding Acutely Stimulates Fibrinogen Synthesis in Healthy Young and Elderly Adults12

    PubMed Central

    Caso, Giuseppe; Mileva, Izolda; Kelly, Patricia; Ahn, Hongshik; Gelato, Marie C.; McNurlan, Margaret A.

    2009-01-01

    Fibrinogen is a positive acute-phase protein and its hepatic synthesis is enhanced following inflammation and injury. However, it is not clear whether fibrinogen synthesis is also responsive to oral nutrients and whether the response to a meal may be affected by age. Our aim in this study was to investigate the acute effect of oral feeding on fibrinogen synthesis in both young and elderly men and women. Fibrinogen synthesis was determined in 3 separate occasions from the incorporation of l[2H5]phenylalanine (43 mg/kg body weight) in 8 young (21–35 y) and 8 elderly (>60 y) participants following the ingestion of water (control), a complete liquid meal (15% protein, 30% fat, and 55% carbohydrate), or only the protein component of the meal. The ingestion of the complete meal enhanced fibrinogen fractional synthesis rates (FSR) by 17 ± 6% in the young and by 38 ± 10% in the elderly participants compared with the water meal (P < 0.02). A comparable stimulation of FSR occurred with only the protein component of the meal in both young (29 ± 7%) and elderly participants (41 ± 9%) compared with the water meal (P < 0.005). Similar results were obtained when fibrinogen synthesis was expressed as absolute synthesis rates (i.e. mg·kg−1·d−1). The results demonstrate that fibrinogen synthesis is acutely stimulated after ingestion of a meal and that this effect can be reproduced by the protein component of the meal alone, both in young and elderly adults. PMID:19759246

  5. Quantitation of platelet and fibrinogen-fibrin deposition on components of tissue valves (Ionescu-Shiley) in calves

    SciTech Connect

    Dewanjee, M.K.; Solis, E.; Lenker, J.; Tidwell, C.; Mackey, S.; Didisheim, P.; Kaye, M.P.

    1986-07-01

    With /sup 111/In-labeled platelets and /sup 125/I-labeled bovine fibrinogen, regional mapping of platelet and fibrinogen deposition on leaflets and sewing rings was obtained. Ten Holstein calves received 25-mm mitral valves (ISLM) and were killed 1, 14, and 30 days after implantation. Twenty-four hours before the calves were killed, 350 to 450 microCi of /sup 111/In-labeled platelets and 200 to 250 microCi of /sup 125/I-labeled bovine fibrinogen were administered intravenously. The components of the tissue valves, i.e., three leaflets and sewing rings, were separated. Each leaflet was cut into four sections: free edge, central zone, flexion zone, and attachment zone. From the radioactivity in blood, leaflet zones, sewing rings, area of leaflet zones, platelet count, and fibrinogen level in blood, the mean regional density of adherent platelets, fibrinogen-fibrin, and fibrinogen/platelet were calculated. The density of platelets and fibrinogen deposited on the components of the valves decreases with time postimplantation. The number of fibrinogen molecules per platelet is fivefold to 20-fold higher than that of the receptor concentration on platelets on leaflet zones, suggesting the heterogeneity of fibrinogen-fibrin in thrombus and components of the valve.

  6. Use of prothrombin complex concentrates and fibrinogen concentrates in the perioperative setting: a systematic review.

    PubMed

    Lin, David M; Murphy, Linda S; Tran, Minh-Ha

    2013-04-01

    The use of prothrombin complex concentrates (PCCs) and fibrinogen concentrates (FIBCs) to achieve hemostasis in the perioperative setting as alternatives to allogeneic blood products remains controversial. To examine the efficacy and safety of PCCs and FIBCs, we conducted a systematic review-in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement-to compare the use of these transfusion alternatives in bleeding surgical patients. We performed a literature search of English articles published between July 1997 and July 2012 in MEDLINE via PubMed, The Cochrane Library, and CINAHL. Five randomized trials and 15 nonrandomized studies with a comparator group were included in the final review. Studies were sorted into 1 of the following 3 clinical settings: cardiac surgery, non-cardiac surgery, and reversal of warfarin anticoagulation. Risk of bias was assessed using the Cochrane risk of bias tool. With the exception of 2 randomized controlled trials, the existing body of literature on the use of PCCs and FIBCs in the perioperative setting was assessed to have a high degree of methodological bias. Overall, prospective studies in the cardiac surgery grouping suggested that patients receiving FIBC and/or PCCs required less allogeneic blood transfusion and had less chest tube drainage. In studies of warfarin reversal, PCCs more rapidly corrected the International Normalized Ratio compared to plasma; however, in the setting of intracranial hemorrhage, functional outcomes were poor regardless of the reversal strategy. With regards to safety outcomes, reporting was not uniform and raises concerns of underreporting. Adequately powered, methodologically sound trials would be required for more definitive conclusions to be drawn about the efficacy of PCCs and FIBC over conventional blood components for the treatment of perioperative coagulopathy in bleeding patients. PMID:23462530

  7. In the rat, citrullinated autologous fibrinogen is immunogenic but the induced autoimmune response is not arthritogenic

    PubMed Central

    Duplan, V; Foulquier, C; Clavel, C; Al Badine, R; Serre, G; Saoudi, A; Sebbag, M

    2006-01-01

    Conversion of arginyl to citrullyl residues (citrullination) is essential for the formation of the epitopes recognized by rheumatoid arthritis (RA)-associated autoantibodies to citrullinated proteins (ACPA). ACPA are secreted by plasma cells of the rheumatoid synovial tissue where their major target, citrullinated fibrin, is abundant. Although numerous arguments suggest that ACPA play an important role in RA, their pathological relevance remains to be established. In the present study, we assessed the immunogenicity and arthritogenicity of complete Freund's adjuvant-emulsified autologous citrullinated (C-rFBG) or non-citrullinated (NC-rFBG) fibrinogen in Lewis (LEW) and Brown–Norway rats, which exhibit drastic differences in their susceptibility to induced autoimmune diseases. NC-rFBG induced no antibody response. In contrast, a single injection of C-rFBG induced an IgG response directed mainly to citrullinated determinants of rFBG. However, all rat strains remained devoid of clinical and histological signs of arthritis up to 3 months after C-rFBG inoculation. Next, in LEW rats, we tested whether autoimmunity to C-rFBG could aggravate acute ankle arthritis triggered by intra-articular injection of incomplete Freund's adjuvant (IFA). However, such arthritis evolved identically in the presence or absence of anti-C-rFBG autoantibodies. However, IFA-injected joints were devoid of citrullinated fibrin deposits. Therefore, citrullination allows breakdown of immunological tolerance but the autoimmune response developed is not spontaneously arthritogenic. Whether or not it can aggravate arthritis with citrullinated fibrin deposits remains to be evaluated. PMID:16907920

  8. Mineralization Potential of Electrospun PDO-Hydroxyapatite-Fibrinogen Blended Scaffolds

    PubMed Central

    Rodriguez, Isaac A.; Madurantakam, Parthasarathy A.; McCool, Jennifer M.; Sell, Scott A.; Yang, Hu; Moon, Peter C.; Bowlin, Gary L.

    2012-01-01

    The current bone autograft procedure for cleft palate repair presents several disadvantages such as limited availability, additional invasive surgery, and donor site morbidity. The present preliminary study evaluates the mineralization potential of electrospun polydioxanone:nano-hydroxyapatite : fibrinogen (PDO : nHA : Fg) blended scaffolds in different simulated body fluids (SBF). Scaffolds were fabricated by blending PDO : nHA : Fg in the following percent by weight ratios: 100 : 0 : 0, 50 : 25 : 25, 50 : 50 : 0, 50 : 0 : 50, 0 : 0 : 100, and 0 : 50 : 50. Samples were immersed in (conventional (c), revised (r), ionic (i), and modified (m)) SBF for 5 and 14 days to induce mineralization. Scaffolds were characterized before and after mineralization via scanning electron microscopy, Alizarin Red-based assay, and modified burnout test. The addition of Fg resulted in scaffolds with smaller fiber diameters. Fg containing scaffolds also induced sheet-like mineralization while individual fiber mineralization was noticed in its absence. Mineralized electrospun Fg scaffolds without PDO were not mechanically stable after 5 days in SBF, but had superior mineralization capabilities which produced a thick bone-like mineral (BLM) layer throughout the scaffolds. 50 : 50 : 0 scaffolds incubated in either r-SBF for 5 days or c-SBF for 14 days produced scaffolds with high mineral content and individual-mineralized fibers. These mineralized scaffolds were still porous and will be further optimized as an effective bone substitute in future studies. PMID:22956956

  9. Fibrinogen Substrate Recognition by Staphylocoagulase·(Pro)thrombin Complexes*

    PubMed Central

    Panizzi, Peter; Friedrich, Rainer; Fuentes-Prior, Pablo; Richter, Klaus; Bock, Paul E.; Bode, Wolfram

    2008-01-01

    Thrombin generation and fibrinogen (Fbg) clotting are the ultimate proteolytic reactions in the blood coagulation pathway. Staphylocoagulase (SC), a protein secreted by the human pathogen Staphylococcus aureus, activates prothrombin (ProT) without proteolysis. The SC·(pro)thrombin complex recognizes Fbg as a specific substrate, converting it directly into fibrin. The crystal structure of a fully active SC fragment containing residues 1–325 (SC-(1–325)) bound to human prethrombin 2 showed previously that SC inserts its Ile1-Val2 N terminus into the Ile16 pocket of prethrombin 2, inducing a functional active site in the cognate zymogen conformationally. Exosite I of α-thrombin, the Fbg recognition site, and proexosite I on ProT are blocked by domain 2 of SC-(1–325). In the present studies, active site-labeled fluorescent ProT analogs were used to quantitate Fbg binding to the SC-(1–325)·ProT complex. Fbg binding and cleavage are mediated by expression of a new Fbg-binding exosite on the SC-(1–325)·ProT complex, resulting in formation of an (SC-(1–325)·ProT)2·Fbg pentameric complex with a dissociation constant of 8–34 nM. In both crystal structures, the SC-(1–325)·(pre)thrombin complexes form dimers, with both pro-teinases/zymogens facing each other over a large U-shaped cleft, through which the Fbg substrate could thread. On this basis, a molecular model of the pentameric (SC-(1–325)·thrombin)2·Fbg encounter complex was generated, which explains the coagulant properties and efficient Fbg conversion. The results provide new insight into the mechanism that mediates high affinity Fbg binding and cleavage as a substrate of SC·(pro)thrombin complexes, a process that is central to the molecular pathology of S. aureus endocarditis. PMID:16230339

  10. Fibrinogen {alpha} genes: Conservation of bipartite transcripts and carboxy-terminal-extended {alpha} subunits in vertebrates

    SciTech Connect

    Fu, Y.; Cao, Y.; Hertzberg, K.M.; Grieninger, G.

    1995-11-01

    All three well-studied subunits of the clotting protein fibrinogen ({alpha}, {beta}, {gamma}) share N-terminal structural homologies, but until recently only the {beta} and {gamma} chains were recognized as having similar globular C-termini. With the discovery of an extra exon in the human fibrinogen {alpha} gene (exon VI), a minor form of the {alpha} subunit ({alpha}{sub E}) with an extended {beta}- and {gamma}-like C-terminus has been identified. In the present study, the polymerase chain reaction has been used to identify sequences that encode counterparts to {alpha}{sub E} in chicken, rabbit, rat, and baboon. The basic six-exon structure of the fibrinogen {alpha} genes is shown to be conserved among mammals and birds, as are the intron positions. Bipartite transcripts - still bearing an intron prior to the last exon - are found among the products of the various vertebrate fibrinogen {alpha} genes. The last exon represents the largest conserved segment of the gene and, in each species examined, encodes exactly 236 amino acids. The C-termini of these {alpha}{sub E} chains align without a single gap and are between 76 and 99% identical. Since the exon VI-encoded domain of {alpha}{sub E} is as well conserved as the corresponding regions of the {beta} and {gamma} chains, it follows that it is equally important and that {alpha}{sub E}-fibrinogen plays a vital, if as-yet unrecognized physiological role. 21 refs., 7 figs., 1 tab.

  11. Receptors for fibrinogen and aggregated beta 2-microglobulin detected in strains of group B streptococci.

    PubMed Central

    Schönbeck, C; Björck, L; Kronvall, G

    1981-01-01

    Binding of radiolabeled human fibrinogen and aggregated beta-microglobulin was measured in 60 strains of beta-hemolytic group B streptococci. Positive fibrinogen binding was detected in seven of the strains. Six of the group B strains showed an uptake of aggregated beta 2-microglobulin. Four individual strains carried both receptors, indicating a positive correlation between their occurrence. Inhibition studies showed that fibrinogen competed sterically with beta 2-microglobulin binding. Receptors for both proteins were trypsin sensitive. The presence of receptors did not correlate with the serological type of the 49 group B strains tested. However, all seven type II strains were negative. No uptake of fibrinogen was noted in any of 40 group D strains tested. Binding structures for fibrinogen and aggregated beta 2-microglobulin detected in group B streptococci were similar to receptors for the same proteins in group A, C, and G streptococci in terms of mutual correlation and steric interference of binding. The occasional occurrence of these receptors also in group B strains might reflect a common origin of some types of surface proteins in gram-positive cocci. PMID:6164650

  12. Blood coagulation protein fibrinogen promotes autoimmunity and demyelination via chemokine release and antigen presentation

    PubMed Central

    Ryu, Jae Kyu; Petersen, Mark A.; Murray, Sara G.; Baeten, Kim M.; Meyer-Franke, Anke; Chan, Justin P.; Vagena, Eirini; Bedard, Catherine; Machado, Michael R.; Coronado, Pamela E. Rios; Prod'homme, Thomas; Charo, Israel F.; Lassmann, Hans; Degen, Jay L.; Zamvil, Scott S.; Akassoglou, Katerina

    2015-01-01

    Autoimmunity and macrophage recruitment into the central nervous system (CNS) are critical determinants of neuroinflammatory diseases. However, the mechanisms that drive immunological responses targeted to the CNS remain largely unknown. Here we show that fibrinogen, a central blood coagulation protein deposited in the CNS after blood–brain barrier disruption, induces encephalitogenic adaptive immune responses and peripheral macrophage recruitment into the CNS leading to demyelination. Fibrinogen stimulates a unique transcriptional signature in CD11b+ antigen-presenting cells inducing the recruitment and local CNS activation of myelin antigen-specific Th1 cells. Fibrinogen depletion reduces Th1 cells in the multiple sclerosis model, experimental autoimmune encephalomyelitis. Major histocompatibility complex (MHC) II-dependent antigen presentation, CXCL10- and CCL2-mediated recruitment of T cells and macrophages, respectively, are required for fibrinogen-induced encephalomyelitis. Inhibition of the fibrinogen receptor CD11b/CD18 protects from all immune and neuropathologic effects. Our results show that the final product of the coagulation cascade is a key determinant of CNS autoimmunity. PMID:26353940

  13. Increased concentration of plasminogen activator inhibitor-1 and fibrinogen in individuals with metabolic syndrome.

    PubMed

    Palomo, Iván G; Gutiérrez, César L; Alarcón, Marcelo L; Jaramillo, Julio C; Segovia, Fabián M; Leiva, Elba M; Mujica, Verónica E; Icaza, Gloria N; Díaz, Nora S; Moore-Carrasco, Rodrigo

    2009-01-01

    Metabolic syndrome (MS) is closely linked to a generalized metabolic disorder referred to as insulin resistance. Disturbances in the hemostasis and fibrinolytic systems are a feature of MS. The aim of this study was to determine the concentration levels of fibrinogen and plasminogen activator inhibitor-1 (PAI-1) in a group of patients with MS with respect to a non-MS group, and to evaluate their possible relation with other risk factors in MS. The study was carried out in a total of 186 male and female non-smoking individuals aged 45-64 years, 93 with MS (ATP III criteria) and 93 without MS. Plasmatic levels of PAI-1 were measured by ELISA, and those of fibrinogen by the Claus method. The plasmatic levels of PAI-1 (men 49.2±19.8 vs. 35.0±12.2 ng/ml and women 42.0±19.7 vs. 31.6±14.6 ng/ml; p=0.0026) and fibrinogen (274.0±82.1 vs. 232.7±66.6 ng/ml; p=0.0002) were significantly higher in the MS group than in the non-MS group. PAI-1 was significantly associated with diastolic blood pressure, triglycerides and waist circumference. Fibrinogen was negatively associated with HDL-c. High plasmatic levels of PAI-1 and fibrinogen contribute to the cardiovascular risk that characterizes individuals with MS. PMID:21475821

  14. Identification of fibrinogen-binding proteins of Aspergillus fumigatus using proteomic approach.

    PubMed

    Upadhyay, Santosh Kumar; Gautam, Poonam; Pandit, Hrishikesh; Singh, Yogendra; Basir, Seemi Farhat; Madan, Taruna

    2012-03-01

    Aspergillus fumigatus, the main etiological agent for various forms of human aspergillosis, gets access to the respiratory system of human host by inhalation of airborne conidia. These conidia possibly adhere to extracellular matrix (ECM) proteins. Among the ECM proteins involved in adherence, fibrinogen is thought to be crucial. Here, we studied whether A. fumigatus three-week culture filtrate (3wcf) proteins promote binding of A. fumigatus to ECM proteins and promote fungal growth. We observed that incubation of ECM with 3wcf proteins led to dose- and time-dependent increase in adherence of conidia to the ECM. In order to identify the catalogue of fibrinogen-binding A. fumigatus proteins, we carried out fibrinogen affinity blotting using two-dimensional gel electrophoresed 3wcf proteins. A total of 15 fibrinogen-binding protein spots corresponding to 7 unique proteins were identified in 3wcf using matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF-TOF). Among these, 4 proteins, namely, beta-glucosidase, alpha-mannosidase, pectate lyase A and oryzin precursor were predicted to have cell wall or extracellular localization, whereas amidase family protein and two hypothetical proteins did not display the signal sequence. This study reports seven novel fibrinogen-binding proteins of A. fumigatus, some of which could be further explored for targeting the adhesion phenomenon as antifungal strategy. PMID:21870122

  15. Crystal structure of the tetrameric fibrinogen-like recognition domain of fibrinogen C domain containing 1 (FIBCD1) protein.

    PubMed

    Shrive, Annette K; Moeller, Jesper B; Burns, Ian; Paterson, Jenny M; Shaw, Amy J; Schlosser, Anders; Sorensen, Grith L; Greenhough, Trevor J; Holmskov, Uffe

    2014-01-31

    The high resolution crystal structures of a recombinant fragment of the C-terminal fibrinogen-like recognition domain of FIBCD1, a vertebrate receptor that binds chitin, have been determined. The overall tetrameric structure shows similarity in structure and aggregation to the horseshoe crab innate immune protein tachylectin 5A. The high affinity ligand N-acetylmannosamine (ManNAc) binds in the S1 site, predominantly via the acetyl group with the oxygen and acetamide nitrogen hydrogen-bonded to the protein and the methyl group inserted into a hydrophobic pocket. The binding of the ManNAc pyranose ring differs markedly between the two independent subunits, but in all structures the binding of the N-acetyl group is conserved. In the native structure, a crystal contact results in one of the independent protomers binding the first GlcNAc of the Asn(340) N-linked glycan on the other independent protomer. In the ligand-bound structure this GlcNAc is replaced by the higher affinity ligand ManNAc. In addition, a sulfate ion has been modeled into the electron density at a location similar to the S3 binding site in L-ficolin, whereas in the native structure an acetate ion has been placed in the S1 N-acetyl binding site, and a sulfate ion has been placed adjacent to this site. These ion binding sites are ideally placed to receive the N-acetyl and sulfate groups of sulfated GalNAc residues of glycosaminoglycans such as chondroitin and dermatan sulfate. Together, these structures give insight into important determinants of ligand selectivity, demonstrating versatility in recognition and binding while maintaining conservation in N-acetyl and calcium binding. PMID:24293368

  16. Leg scanning with radioisotope-labeled fibrinogen in patients undergoing hip surgery

    SciTech Connect

    LeMoine, J.R.; Moser, K.M.

    1980-05-01

    To establish whether radioisotope-labeled fibrinogen leg scanning is of value in the context of hip surgery, we propsectively studied 21 consectuvie patients undergoing either total hip replacement (14) or open repair of a hip fracture (seven) with leg scans, contrast phlebography, and ventilation and perfusion lung scans. We found that in eight patients (38%), venous thromboembolism developed postoperatively. Agreement between phlebographic and leg scanning results was excellent. In no patient as venous thrombosis limited to the thigh on the operated-on side, a vital consideration in application of fibrinogen leg scanning to this patient population. Two patients had lung scan changes indicative of embolism; both had thrombi extending into thigh veins. Leg scanning with radioisotope-labeled fibrinogen appears to be a useful method for monitoring patients undergoing hip surgery, if the upper three counting points on the operated-on side are excluded.

  17. Cleavage of fibrinogen by proteinases elicits allergic responses through Toll-like receptor 4.

    PubMed

    Millien, Valentine Ongeri; Lu, Wen; Shaw, Joanne; Yuan, Xiaoyi; Mak, Garbo; Roberts, Luz; Song, Li-Zhen; Knight, J Morgan; Creighton, Chad J; Luong, Amber; Kheradmand, Farrah; Corry, David B

    2013-08-16

    Proteinases and the innate immune receptor Toll-like receptor 4 (TLR4) are essential for expression of allergic inflammation and diseases such as asthma. A mechanism that links these inflammatory mediators is essential for explaining the fundamental basis of allergic disease but has been elusive. Here, we demonstrate that TLR4 is activated by airway proteinase activity to initiate both allergic airway disease and antifungal immunity. These outcomes were induced by proteinase cleavage of the clotting protein fibrinogen, yielding fibrinogen cleavage products that acted as TLR4 ligands on airway epithelial cells and macrophages. Thus, allergic airway inflammation represents an antifungal defensive strategy that is driven by fibrinogen cleavage and TLR4 activation. These findings clarify the molecular basis of allergic disease and suggest new therapeutic strategies. PMID:23950537

  18. Surface Induced Self-Assembly of Fibrinogen Fibers in the Absence of Thrombin

    NASA Astrophysics Data System (ADS)

    Koo, Jaseung; Rafailovich, Miriam; Galanakis, Dennis

    2009-03-01

    Wound healing is a complex process imitated by the formation of fibrin fibers that are involved in clot formation and fibroblast migration. Normally this process is triggered by thrombin cleavage of the E domain on the fibrinogen molecules, which allows them to spontaneously self-assemble into the fibers. Here we demonstrate that this process can also be initiated in the absence of thrombin. We show that by simply placing the proteins in contact with hydrocarbon functionalized clay surfaces, molecular reorientation occurs which allows fibers to form from the intact fibrinogen protein. Furthermore, using monoclonal antibodies, we determined which regions on the αC domains are involved in the formation of the new fibrinogen fibers. This allowed us to extend these findings to general hydrophobic surfaces, such as those presented by most hydrocarbon polymers. On the other hand, the carboxyl terminal part of the Aα chain, can interact with amine containing polymers, and suppress formation of the fibers.

  19. Social connectedness is associated with fibrinogen level in a human social network.

    PubMed

    Kim, David A; Benjamin, Emelia J; Fowler, James H; Christakis, Nicholas A

    2016-08-31

    Socially isolated individuals face elevated rates of illness and death. Conventional measures of social connectedness reflect an individual's perceived network and can be subject to bias and variation in reporting. In this study of a large human social network, we find that greater indegree, a sociocentric measure of friendship and familial ties identified by a subject's social connections rather than by the subject, predicts significantly lower concentrations of fibrinogen (a biomarker of inflammation and cardiac risk), after adjusting for demographics, education, medical history and known predictors of cardiac risk. The association between fibrinogen and social isolation, as measured by low indegree, is comparable to the effect of smoking, and greater than that of low education, a conventional measure of socioeconomic disadvantage. By contrast, outdegree, which reflects an individual's perceived connectedness, displays a significantly weaker association with fibrinogen concentrations. PMID:27559060

  20. KSTAR Equilibrium Operating Space and Projected Stabilization at High Normalized Beta

    SciTech Connect

    Park, Y. S.; Sabbagh, S. A.; Berkery, J.W.; Bialek, J.; Jeon, Y. M.; Hahn, S. H.; Eidietis, N. W.; Evans, T. E.; Yoon, S. W.; Ahn, Joonwook; Kim, J.; Yang, H. L.; You, K. I.; Soukhanovskii, V. A.; Bae, Y. S.; Chung, J. I.; Kwon, M.; Oh, Y. K.; Kim, W. C.; Kim, J. Y.; Lee, S. G.; Park, H.; Reimerdes, H.; Leuer, J. A.; Walker, M. L.

    2011-01-01

    Along with an expanded evaluation of the equilibrium operating space of the Korea Superconducting Tokamak Advanced Research, KSTAR, experimental equilibria of the most recent plasma discharges were reconstructed using the EFIT code. In near-circular plasmas created in 2009, equilibria reached a stored energy of 54 kJ with a maximum plasma current of 0.34 MA. Highly shaped plasmas with near double-null configuration in 2010 achieved H-mode with clear edge localized mode (ELM) activity, and transiently reached a stored energy of up to 257 kJ, elongation of 1.96 and normalized beta of 1.3. The plasma current reached 0.7 MA. Projecting active and passive stabilization of global MHD instabilities for operation above the ideal no-wall beta limit using the designed control hardware was also considered. Kinetic modification of the ideal MHD n = 1 stability criterion was computed by the MISK code on KSTAR theoretical equilibria with a plasma current of 2 MA, internal inductance of 0.7 and normalized beta of 4.0 with simple density, temperature and rotation profiles. The steep edge pressure gradient of this equilibrium resulted in the need for significant plasma toroidal rotation to allow thermal particle kinetic resonances to stabilize the resistive wall mode (RWM). The impact of various materials and electrical connections of the passive stabilizing plates on RWM growth rates was analysed, and copper plates reduced the RWM passive growth rate by a factor of 15 compared with stainless steel plates at a normalized beta of 4.4. Computations of active RWM control using the VALEN code showed that the n = 1 mode can be stabilized at normalized beta near the ideal wall limit via control fields produced by the midplane in-vessel control coils (IVCCs) with as low as 0.83kW control power using ideal control system assumptions. The ELM mitigation potential of the IVCC, examined by evaluating the vacuum island overlap created by resonant magnetic perturbations, was analysed using the

  1. FbsC, a Novel Fibrinogen-binding Protein, Promotes Streptococcus agalactiae-Host Cell Interactions*

    PubMed Central

    Buscetta, Marco; Papasergi, Salvatore; Firon, Arnaud; Pietrocola, Giampiero; Biondo, Carmelo; Mancuso, Giuseppe; Midiri, Angelina; Romeo, Letizia; Teti, Giuseppe; Speziale, Pietro; Trieu-Cuot, Patrick; Beninati, Concetta

    2014-01-01

    Streptococcus agalactiae (group B Streptococcus or GBS) is a common cause of invasive infections in newborn infants and adults. The ability of GBS to bind human fibrinogen is of crucial importance in promoting colonization and invasion of host barriers. We characterized here a novel fibrinogen-binding protein of GBS, designated FbsC (Gbs0791), which is encoded by the prototype GBS strain NEM316. FbsC, which bears two bacterial immunoglobulin-like tandem repeat domains and a C-terminal cell wall-anchoring motif (LPXTG), was found to be covalently linked to the cell wall by the housekeeping sortase A. Studies using recombinant FbsC indicated that it binds fibrinogen in a dose-dependent and saturable manner, and with moderate affinity. Expression of FbsC was detected in all clinical GBS isolates, except those belonging to the hypervirulent lineage ST17. Deletion of fbsC decreases NEM316 abilities to adhere to and invade human epithelial and endothelial cells, and to form biofilm in vitro. Notably, bacterial adhesion to fibrinogen and fibrinogen binding to bacterial cells were abolished following fbsC deletion in NEM316. Moreover, the virulence of the fbsC deletion mutant and its ability to colonize the brain were impaired in murine models of infection. Finally, immunization with recombinant FbsC significantly protected mice from lethal GBS challenge. In conclusion, FbsC is a novel fibrinogen-binding protein expressed by most GBS isolates that functions as a virulence factor by promoting invasion of epithelial and endothelial barriers. In addition, the protein has significant immunoprotective activity and may be a useful component of an anti-GBS vaccine. PMID:24904056

  2. An alternative pathway for fibrinolysis. I. The cleavage of fibrinogen by leukocyte proteases at physiologic pH.

    PubMed Central

    Plow, E F; Edgington, T S

    1975-01-01

    An alternative fibrinolytic system, active at physiological pH, is present in peripheral blood leukocytes. The fibrinolytic proteases localized predominantly in the leukocyte granules are capable of degrading both fibrinogen and fibrin, and plasmin activity does not contribute significantly to this proteolytic event. The specificity of the alternative fibrinolytic proteases for fibrinogen and the characteristics of the derivative cleavage fragments are clearly distinguishable from the classical plasmin system. The high molecular weight derivatives of fibrinogen, generated by the alternative system, under physiological conditions, are larger than the plasmin-generated X fragment, exhibit immunoelectrophoretic mobility comparable to native fibrinogen, and are not coagulable by thrombin. Analysis of the constituent polypeptide chains of the fragments reveals cleavage of the Aalpha, Bbeta, and gamma chains of fibrinogen. The lower molecular weight derivatives of fibrinogen, generated by the alternative system, are structurally distinct from previously described fibrinogen degradation products and exhibit potent anticoagulant activity. This anticoagulant activity can be attributed to interference with normal fibrin polymerization. The proteases of the alternative fibrinolytic systems are actively secreted by leukocytes when stimulated to undergo a nonlytic release reaction. These results provide direct evidence for a fibrinolytic system resident in leukocyte granules that is associated with the leukocyte release reaction and is capable of generating unique fibrinogen cleavage fragments. Images PMID:237938

  3. A comparative evaluation of assays for markers of activated coagulation and/or fibrinolysis: thrombin-antithrombin complex, D-dimer and fibrinogen/fibrin fragment E antigen.

    PubMed

    Boisclair, M D; Lane, D A; Wilde, J T; Ireland, H; Preston, F E; Ofosu, F A

    1990-04-01

    Measurements were made of levels of D-dimer in plasma and serum, thrombin-antithrombin complex (TAT) in plasma and fibrinogen/fibrin fragment E antigen (FgE) in serum in a normal healthy control group and in patients with a range of disorders associated with hypercoagulability. Levels were determined in 31 normal healthy controls, 30 patients with disseminated intravascular coagulation (DIC), 21 patients with deep venous thrombosis (DVT), 27 patients with myocardial infarction (MI), 26 patients with acute leukaemia and 56 patients with liver disease. Considering all subjects, significant correlations were established between the results of all assays. Notably high correlations (r greater than 0.9) were established between plasma and serum levels of D-dimer, between plasma levels of D-dimer and serum levels of FgE, and between serum levels of D-dimer and FgE. All assays showed very high discrimination (sensitivity) between the normal control group and patients with DIC (97-100%), but there were marked differences between the assays in sensitivity for DVT and MI. In general, the FgE assay was more sensitive than the D-dimer assay, whilst both the FgE and D-dimer assays were more sensitive than the TAT assay. The same trends were apparent in the capability of the assays to discriminate between the normal control group and patients with acute leukaemia and liver disease: disorders with an unknown prevalence of activation of coagulation/fibrinolysis. Our results indicated that measurements of fibrinogen/fibrin degradation products (FDPs) in serum were almost unaffected by artefacts. The data further suggested that the broad-spectrum FgE assay was better than the more specific D-dimer assay in detecting clinical hypercoagulability. Our study showed that, in the clinical conditions examined, FDPs were more effective markers of hypercoagulability than TAT. PMID:2189490

  4. Effect of Fibrinogen on Platelet Reactivity Measured by the VerifyNow P2Y12 Assay.

    PubMed

    Dobrovolsky, A B; Laguta, P S; Guskova, E V; Yarovaya, E B; Titaeva, E V; Storozhilova, A N; Panchenko, E P

    2016-05-01

    The VerifyNow assay is based upon the ability of activated platelets to cross-link beads coated with fibrinogen. However, fibrinogen is an abundant protein of blood, and therefore it may affect test results by competing with fibrinogen of beads for binding to platelets. To test this assumption, we assessed the influence of artificial alteration of fibrinogen level in blood samples obtained from donors (n = 9) and patients on clopidogrel therapy (n = 8) on the results of the VerifyNow P2Y12 assay. Fibrinogen level was altered by adding to blood samples 1/10 volume of fibrinogen solution (10.56 g/liter) or corresponding buffer. Relative to baseline, addition of buffer significantly increased platelet reactivity, whereas addition of fibrinogen decreased it. Analysis of the relationship between change in platelet reactivity values (dBase and dPRU) and change in fibrinogen concentration (dFg) revealed strong negative correlations: dBase = -63.3 × dFg - 27.1 (r = -0.924, p < 0.0005) and dPRU = -54.4 × dFg - 21.8 (r = -0.764, p < 0.0005). Thus, the results of our experiments suggest that: (i) blood fibrinogen strongly influences results of the VerifyNow P2Y12 assay, and (ii) correcting for fibrinogen effect may be needed to improve the accuracy of the test in the measuring of antiplatelet effect of clopidogrel therapy. PMID:27297894

  5. Oleic acid-induced lung injury in rabbits: effect of fibrinogen depletion with Arvin

    SciTech Connect

    Allard, M.F.; Doerschuk, C.M.; Brumwell, M.L.; Belzberg, A.; Hogg, J.C.

    1988-03-01

    The role of fibrinogen in the evolution of the increased permeability after oleic acid-induced lung injury was studied in New Zealand White rabbits. Animals depleted of fibrinogen by treatment with Malayan pit viper venom were compared with untreated rabbits immediately and at 1 and 24 h after injury. The increased permeability to albumin and elevated extravascular lung water (EVLW) associated with lung injury returned to control values by 24 h in untreated animals. Fibrinogen-depleted animals had a higher mortality (10/25 vs. 2/17, P less than 0.02) and showed a greater immediate increase in permeability to albumin that returned to control values at 1 and 24 h after injury, as well as trends toward elevated blood-free dry lung weight and larger increases in EVLW that persisted for 24 h. These findings indicate that fibrinogen-related proteins play an important role in controlling the microvascular injury that is produced by oleic acid. However, when these proteins are depleted, other mechanisms partially control the leak at later stages of the repair process.

  6. Group B Streptococcal Serine-Rich Repeat Proteins Promote Interaction With Fibrinogen and Vaginal Colonization

    PubMed Central

    Wang, Nai-Yu; Patras, Kathryn A.; Seo, Ho Seong; Cavaco, Courtney K.; Rösler, Berenice; Neely, Melody N.; Sullam, Paul M.; Doran, Kelly S.

    2014-01-01

    Group B streptococcus (GBS) can cause severe disease in susceptible hosts, including newborns, pregnant women, and the elderly. GBS serine-rich repeat (Srr) surface glycoproteins are important adhesins/invasins in multiple host tissues, including the vagina. However, exact molecular mechanisms contributing to their importance in colonization are unknown. We have recently determined that Srr proteins contain a fibrinogen-binding region (BR) and hypothesize that Srr-mediated fibrinogen binding may contribute to GBS cervicovaginal colonization. In this study, we observed that fibrinogen enhanced wild-type GBS attachment to cervical and vaginal epithelium, and that this was dependent on Srr1. Moreover, purified Srr1-BR peptide bound directly to host cells, and peptide administration in vivo reduced GBS recovery from the vaginal tract. Furthermore, a GBS mutant strain lacking only the Srr1 “latching” domain exhibited decreased adherence in vitro and decreased persistence in a mouse model of GBS vaginal colonization, suggesting the importance of Srr–fibrinogen interactions in the female reproductive tract. PMID:24620021

  7. Forced Unfolding of the Coiled-Coils of Fibrinogen by Single-Molecule AFM

    NASA Astrophysics Data System (ADS)

    Brown, Andre; Litvinov, Rustem; Discher, Dennis; Weisel, John

    2007-03-01

    A blood clot needs to have the right degree of stiffness and plasticity for hemostasis, but the origin of these mechanical properties is unknown. Here we report the first measurements using single molecule atomic force microscopy (AFM) to study the forced unfolding of fibrinogen to begin addressing this problem. To generate longer reproducible curves than are possible using monomer, factor XIIIa cross-linked, single chain fibrinogen oligomers were used. When extended under force, these oligomers showed sawtooth shaped force-extension patterns characteristic of unfolding proteins with a peak-to-peak separation of approximately 26 nm, consistent with the independent unfolding of the coiled-coils. These results were then reproduced using a Monte Carlo simulation with parameters in the same range as those previously used for unfolding globular domains. In particular, we found that the refolding time was negligible on experimental time and force scales in contrast to previous work on simpler coiled-coils. We suggest that this difference may be due to fibrinogen's structurally and topologically more complex coiled-coils and that an interaction between the alpha C and central domains may be involved. These results suggest a new functional property of fibrinogen and that the coiled-coil is more than a passive structural element of this molecule.

  8. [Fixing of osteochondral fragments with fibrinogen glue. Clinical experiences (author's transl)].

    PubMed

    Zilch, H; Friedebold, G

    1981-08-01

    Small osteochondral fragments are well fixed with the fibrinogen glue. This method is really a progress in comparison with the traditional fixation by screws or K-wires. The fragments were revascularized early. This is demonstrated by 31 glued osteochondral fragments which healed well. The joints must be immobilized during a period of 3 weeks. PMID:6118021

  9. Problems with nonspecific binding in radioimmunoassay for fibrinogen fragment D

    SciTech Connect

    Thornton, R.D.; Kulkarni, P.; Wilson, J.E.

    1982-07-01

    Because of problems associated with non-specific binding in the competetive inhibition radioimmunoassay, the author, in a letter, recommends running a blank (without the first antibody) for each dilution of the antigen. He adds, further, that normal human plasma can be used a diluent when preparing standard curves if non-specific binding is found. (JMT)

  10. Revealing fibrinogen monolayer conformations at different pHs: electrokinetic and colloid deposition studies.

    PubMed

    Nattich-Rak, Małgorzata; Adamczyk, Zbigniew; Wasilewska, Monika; Sadowska, Marta

    2015-07-01

    Adsorption mechanism of human fibrinogen on mica at different pHs is studied using the streaming potential and colloid deposition measurements. The fibrinogen monolayers are produced by a controlled adsorption under diffusion transport at pH of 3.5 and 7.4. Initially, the electrokinetic properties of these monolayers and their stability for various ionic strength are determined. It is shown that at pH 3.5 fibrinogen adsorbs irreversibly on mica for ionic strength range of 4×10(-4) to 0.15 M. At pH 7.4, a partial desorption is observed for ionic strength below 10(-2) M. This is attributed to the desorption of the end-on oriented molecules whereas the side-on adsorbed molecules remain irreversibly bound at all ionic strengths. The orientation of molecules and monolayer structure is evaluated by the colloid deposition measurements involving negatively charged polystyrene latex microspheres, 820 nm in diameter. An anomalous deposition of negative latex particles on substrates exhibiting a negative zeta potential is observed. At pH 3.5 measurable deposition of latex is observed even at low ionic strength where the approach distance of latex particles exceeded 70 nm. At pH 7.4 this critical distance is 23 nm. This confirms that fibrinogen monolayers formed at both pHs are characterized by the presence of the side-on and end-on oriented molecules that prevail at higher coverage range. It is also shown that positive charge is located at the end parts of the αA chains of the adsorbed fibrinogen molecules. Therefore, it is concluded that the colloid deposition method is an efficient tool for revealing protein adsorption mechanisms at solid/electrolyte interfaces. PMID:25453169

  11. The novel fibrinogen-binding protein FbsB promotes Streptococcus agalactiae invasion into epithelial cells.

    PubMed

    Gutekunst, Heike; Eikmanns, Bernhard J; Reinscheid, Dieter J

    2004-06-01

    Streptococcus agalactiae is a major cause of bacterial sepsis and meningitis in human newborns. The interaction of S. agalactiae with host proteins and the entry into host cells thereby represent important virulence traits of these bacteria. The present report describes the identification of the fbsB gene, encoding a novel fibrinogen-binding protein that plays a crucial role in the invasion of S. agalactiae into human cells. In Western blots and enzyme-linked immunosorbent assay (ELISA) experiments, the FbsB protein was demonstrated to interact with soluble and immobilized fibrinogen. Binding studies showed the N-terminal 388 residues of FbsB and the Aalpha-subunit of human fibrinogen to recognize each other. By reverse transcription (RT)-PCR, the fbsB gene was shown to be cotranscribed with the gbs0851 gene in S. agalactiae. Deletion of the fbsB gene in the genome of S. agalactiae did not influence the binding of the bacteria to fibrinogen, suggesting that FbsB does not participate in the attachment of S. agalactiae to fibrinogen. In tissue culture experiments, however, the fbsB deletion mutant was severely impaired in its invasion into lung epithelial cells. Bacterial invasion could be reestablished by introducing the fbsB gene on a shuttle plasmid into the fbsB deletion mutant. Furthermore, treatment of lung epithelial cells with FbsB fusion protein blocked S. agalactiae invasion of epithelial cells in a dose-dependent fashion. These results suggest an important role of the FbsB protein in the overall process of host cell entry by S. agalactiae. PMID:15155657

  12. Fibrinogen Availability and Coagulation Function after Hemorrhage and Resuscitation in Pigs

    PubMed Central

    Martini, Wenjun Z

    2011-01-01

    Hemorrhagic coagulopathy (without neurological injuries) constitutes 40% of injury-related death in civilian hospitals and on the battlefield, and the underlying contributing mechanisms remain unclear. The purpose of this study is to investigate the effects of fibrinogen availability on coagulation function after hemorrhage in pigs. Sixteen crossbred commercial Yorkshire swine were randomized into the control group (group C) (n = 8) and hemorrhage group (group H) (n = 8). Hemorrhage was induced in group H by bleeding 35% of the estimated total blood volume, followed by resuscitation with lactated Ringer solution at three times the bled volume. Pigs in group C were not hemorrhaged or resuscitated. Blood samples were withdrawn at baseline, 15 min, 3 h, 6 h, and 24 h after hemorrhage and lactated Ringer (LR) resuscitation (H–LR). Coagulation was assessed by using thrombelastography. All baseline measurements were similar between groups C and H. Hemorrhage caused a decrease in mean arterial pressure and an increase in heart rate in group H, but LR resuscitation corrected these changes within 1 h. Compared to baseline values, fibrinogen concentrations in group H decreased at 15 min, 3 h and 6 h after H–LR, but increased to double that of the baseline value at 24 h; platelet counts decreased throughout the study; clot strength was decreased at 15 min, 3 h and 6 h, but returned to baseline value at 24 h after H–LR. Hemorrhage caused decreases in fibrinogen and platelets, and compromised clot strength. The rebound of fibrinogen at 24 h restored clot strength despite platelet deficit. These data suggest the potential compensatory role of fibrinogen in restoring coagulation function in vivo after hemorrhagic shock. PMID:21327301

  13. Signal transduction pathways in erythrocyte nitric oxide metabolism under high fibrinogen levels

    NASA Astrophysics Data System (ADS)

    Saldanha, Carlota; Freitas, T.; Lopez de Almeida, J. P.; Silva-Herdade, A.

    2014-05-01

    Previous studies show that the fibrinogen molecule modulates the metabolism of nitric oxide (NO) in erythrocyte. The in vitro induced hiperfibrinogenemia interferes in the metabolism of the NO in the erythrocyte in dependence of the phosphorylation degree of the band 3. The soluble form of fibrinogen binds into CD47 protein present in the erythrocyte membrane. The soluble thrombomodulin is an inflammatory marker that binds to the erythrocyte CD47 in a site with a sequence peptide known as 4N1K. A study done in vitro shows that when hiperfibrinogenemia was induced in the presence of the peptide 4N1K agonist of CD47 it were observed variations in the efflux of NO from erythrocyte and an increase in the concentrations of GSNO, peroxinitrite, nitrite and nitrate of the erythrocytes. The aim of this work was to study the influence of the peptide 4N1K, on the metabolism of NO in the erythrocyte under high fibrinogen concentration and in the presence of inhibitors of the status of phosphorylation of protein band 3. In this in vitro study, whole blood samples were harvested from healthy subjects and NO, peroxynitrite, nitrite, nitrate and S-nitro-glutathione (GSNO) were determined in presence of 4N1K, calpeptine, Syk inhibitor and under high fibrinogen concentrations. The results obtained in erythrocytes under high fibrinogen levels when 4N1K is present with the Syk inhibitor or with calpeptine, showed in relation to the control samples increased significant concentrations of efflux of NO and of peroxynitrite, nitrite, nitrate and GSNO. In conclusion it was verified that in the in vitro model of hiperfibrinogenemia the peptide 4N1K, agonist of CD47, induces mobilization of NO in the erythrocyte in dependence of the status of phosphorylation of protein band 3.

  14. Changes in fibrinogen availability and utilization in an animal model of traumatic coagulopathy

    PubMed Central

    2013-01-01

    Background Impaired haemostasis following shock and tissue trauma is frequently detected in the trauma setting. These changes occur early, and are associated with increased mortality. The mechanism behind trauma-induced coagulopathy (TIC) is not clear. Several studies highlight the crucial role of fibrinogen in posttraumatic haemorrhage. This study explores the coagulation changes in a swine model of early TIC, with emphasis on fibrinogen levels and utilization of fibrinogen. Methods A total of 18 landrace pigs were anaesthetized and divided into four groups. The Trauma-Shock group (TS) were inflicted bilateral blast femoral fractures with concomitant soft tissue injury by a high-energy rifle shot to both hind legs, followed by controlled exsanguination. The Shock group (S) was exposed to shock by exsanguination, whereas a third group was exposed to trauma only (T). A fourth group (C) served as control. Physiological data, haematological measurements, blood gas analyses and conventional coagulation assays were recorded at baseline and repeatedly over 60 minutes. Thrombelastometry were performed by means of the tissue factor activated ExTEM assay and the platelet inhibiting FibTEM assay. Data were statistically analysed by repeated measurements analyses method. Results A significant reduction of fibrinogen concentration was observed in both the TS and S groups. INR increased significantly in the S group and differed significantly from the TS group. Maximum clot firmness (MCF) of the ExTEM assay was significantly reduced over time in both TS and S groups. In the FibTEM assay a significant shortening of the clotting time and an increase in MCF was observed in the TS group compared to the S group. Conclusion Despite a reduction in clotting capability measured by ExTEM MCF and a reduced fibrinogen concentration, extensive tissue trauma may induce an increased fibrin based clotting activity that attenuates the hypocoagulable tendency in exsanguinated animals. PMID

  15. Immunohistochemical evaluation of tissue factor, fibrin/fibrinogen and D-dimers in canine gliomas.

    PubMed

    de la Fuente, Cristian; Pumarola, Martí; Blasco, Ester; Fernández, Francisco; Viu, Judit; Añor, Sònia

    2014-06-01

    In human gliomas, tissue factor (TF) is overexpressed, associated with the grade of malignancy and influences tumour biology. Intra-tumoural fibrin/fibrinogen deposition and activation of the fibrinolytic system also play a role in tumour cell proliferation and angiogenesis. The first aim of the present study was to investigate TF expression and the presence of fibrin/fibrinogen and D-dimers in canine glioma biopsies, graded according to the World Health Organization (WHO) classification of tumours of the central nervous system. The second aim was to investigate the occurrence of intravascular thrombosis (IVT) in canine gliomas, as a potential histological marker of glioma type or grade of malignancy. An immunohistochemical study using antibodies against TF, fibrin/fibrinogen and D-dimers was performed with 24 glioma samples, including 15 oligodendrogliomas, 6 astrocytomas and 3 mixed gliomas. Immunohistochemical data were statistically analysed to determine whether there was any relationship between glioma type and grade of malignancy. All gliomas were moderate to strongly positive for TF and the staining score was significantly higher (P = 0.04) in high-grade (III or IV) than in low-grade (II) gliomas. Intra-tumoural fibrin/fibrinogen deposition was detected in all tumour biopsies assessed, and D-dimers were detected in 17/24 gliomas. IVT was a frequent finding, but was not linked to a specific glioma type or malignancy grade. TF expression, fibrin/fibrinogen deposition, extravascular fibrinolytic system activation and IVT occur in canine gliomas. Canine glioma might be a suitable model for studying coagulation and fibrinolysis as potential therapeutic targets for human gliomas. PMID:24745770

  16. Fibrinogen and thrombin concentrations are critical for fibrin glue adherence in rat high-risk colon anastomoses

    PubMed Central

    Buen, Eliseo Portilla-de; Orozco-Mosqueda, Abel; Leal-Cortés, Caridad; Vázquez-Camacho, Gonzalo; Fuentes-Orozco, Clotilde; Alvarez-Villaseñor, Andrea Socorro; Macías-Amezcua, Michel Dassaejv; González-Ojeda, Alejandro

    2014-01-01

    OBJECTIVE: Fibrin glues have not been consistently successful in preventing the dehiscence of high-risk colonic anastomoses. Fibrinogen and thrombin concentrations in glues determine their ability to function as sealants, healers, and/or adhesives. The objective of the current study was to compare the effects of different concentrations of fibrinogen and thrombin on bursting pressure, leaks, dehiscence, and morphology of high-risk ischemic colonic anastomoses using fibrin glue in rats. METHODS: Colonic anastomoses in adult female Sprague-Dawley rats (weight, 250-350 g) treated with fibrin glue containing different concentrations of fibrinogen and thrombin were evaluated at post-operative day 5. The interventions were low-risk (normal) or high-risk (ischemic) end-to-end colonic anastomoses using polypropylene sutures and topical application of fibrinogen at high (120 mg/mL) or low (40 mg/mL) concentrations and thrombin at high (1000 IU/mL) or low (500 IU/mL) concentrations. RESULTS: Ischemia alone, anastomosis alone, or both together reduced the bursting pressure. Glues containing a low fibrinogen concentration improved this parameter in all cases. High thrombin in combination with low fibrinogen also improved adherence exclusively in low-risk anastomoses. No differences were detected with respect to macroscopic parameters, histopathology, or hydroxyproline content at 5 days post-anastomosis. CONCLUSIONS: Fibrin glue with a low fibrinogen content normalizes the bursting pressure of high-risk ischemic left-colon anastomoses in rats at day 5 after surgery. PMID:24714834

  17. Selective Plasma Exchange for Critically Ill Patients Accompanied With Thrombocytopenia.

    PubMed

    Nakae, Hajime; Fukuda, Hirokazu; Okuyama, Manabu; Igarashi, Toshiko

    2016-08-01

    Selective plasma exchange is a blood purification therapy in which simple plasma exchange is performed using a selective membrane plasma separator (pore size of 0.03 µm). Seven critically ill patients accompanied with thrombocytopenia were treated with selective plasma exchange using fresh frozen plasma. The total bilirubin levels and prothrombin time international normalized ratios decreased significantly after treatment. The total protein, albumin, and fibrinogen levels increased significantly after treatment. Selective plasma exchange may be a useful blood purification therapy for removing causal substances and retaining coagulation factors in patients accompanied with thrombocytopenia. PMID:27523072

  18. The use of fibrinogen uptake test in screening for deep vein thrombosis in patients with hip fracture

    SciTech Connect

    Fauno, P.; Suomalainen, O.; Bergqvist, D.; Fredin, H.; Kettunen, K.; Soimakallio, S.; Cederholm, C.; Karjalainen, P.; Vissinger, H.; Justesen, T. )

    1990-11-01

    255 hip fracture patients were studied by {sup 125}I-fibrinogen uptake test and bilateral phlebography. We found the sensitivity of fibrinogen scanning to be 44% for the non-operated limb and 50% for the calves. The predictive value of a negative result was found to be 92% and 93% respectively. We conclude that the use of fibrinogen uptake test as single diagnosticum is not valid and can only be recommended in combination with phlebography when studying patient where the frequency of DVT is expected to be low.

  19. The Dual Role of Fibrinogen as Inhibitor and Nucleator of Calcium Phosphate Phases: The Importance of Structure.

    PubMed

    Tsortos; Ohki; Zieba; Baier; Nancollas

    1996-01-15

    Constant composition and free drift methods have been used to investigate the abilities of human serum albumin (HSA) and fibrinogen to influence calcium phosphate precipitation. Both molecules inhibit hydroxyapatite (HAP) crystal growth when present in the solution phase. Fibrinogen, when immobilized at hydrophobicized germanium or silica surfaces, is able to nucleate calcium phosphate phases; at clean germanium or silica surfaces, it appears to be inactive. The apparent configuration of fibrinogen molecules at germanium or silica surfaces on which octadecyltrichlorosilane (OTS) was deposited probably exposes more negative sites for participation in nucleation. PMID:10479440

  20. Aggregation efficiency of activated normal or fixed platelets in a simple shear field: effect of shear and fibrinogen occupancy.

    PubMed Central

    Xia, Z; Frojmovic, M M

    1994-01-01

    Shear rate can affect protein adsorption and platelet aggregation by regulating both the collision frequency and the capture efficiency (alpha). These effects were evaluated in well defined shear field in a micro-couette for shear rate G = 10 - 1000 s-1. The rate of protein binding was independent of G, shown for adsorption of albumin to latex beads and PAC1 to activated platelets. The initial aggregation rate for ADP-activated platelets in citrated platelet-rich plasma followed second order kinetics at the initial platelet concentrations between 20,000 and 60,000/microliters. alpha values, which dropped nearly fivefold for a 10-fold increase in G, were approximately proportional to G-1, contrary to a minor drop predicted by the theory that includes protein cross-bridging. Varying ADP concentration did not change alpha of maximally activated platelet subpopulations, suggesting that aggregation between unactivated and activated platelets is negligible. Directly blocking the unoccupied but activated GPIIb-IIIa receptors without affecting pre-bound Fg on "RGD"-activated, fixed platelets (AFP) by GRGDSP or Ro 43-5054 eliminated aggregation, suggesting that cross-bridging of GPIIb-IIIa on adjacent platelets by fibrinogen mediates aggregation. Alpha for AFP remained maximal (approximately 0.24) over 25-75% Fg occupancy, otherwise decreasing rapidly, with a half-maximum occurring at around 2% occupancy, suggesting that very few bound Fg were required to cause significant aggregation. Images FIGURE 1 PMID:8075353

  1. A regenerative label-free fiber optic sensor using surface plasmon resonance for clinical diagnosis of fibrinogen

    PubMed Central

    Nguyen, Tan Tai; Bea, Sun Oh; Kim, Dong Min; Yoon, Won Jung; Park, Jin-Won; An, Seong Soo A; Ju, Heongkyu

    2015-01-01

    Purpose We present the regenerative label-free fiber optical biosensor that exploits surface plasmon resonance for quantitative detection of fibrinogen (Fbg) extracted from human blood plasma. Materials and methods The sensor head was made up of a multimode optical fiber with its polymer cladding replaced by metal composite of nanometer thickness made of silver, aluminum, and nickel. The Ni layer coated allowed a direct immobilization of histidine-tagged peptide (HP) on its metal surface without an additional cross-linker in between. On the coated HP layer, immunoglobulin G was then immobilized for specific capturing of Fbg. Results We demonstrated a real-time quantitative detection of Fbg concentrations with limit of detection of ~10 ng/mL. The fact that the HP layer could be removed by imidazole with acid also permitted us to demonstrate the regeneration of the outermost metal surface of the sensor head for the sensor reusability. Conclusion The sensor detection limit was estimated to be ~10 pM, which was believed to be sensitive enough for detecting Fbg during the clinical diagnosis of cardiovascular diseases, myocardial infarction, strokes, and Alzheimer’s diseases. PMID:26347331

  2. Evidence for Steric Regulation of Fibrinogen Binding to Staphylococcus aureus Fibronectin-binding Protein A (FnBPA)*

    PubMed Central

    Stemberk, Vaclav; Jones, Richard P. O.; Moroz, Olga; Atkin, Kate E.; Edwards, Andrew M.; Turkenburg, Johan P.; Leech, Andrew P.; Massey, Ruth C.; Potts, Jennifer R.

    2014-01-01

    The adjacent fibrinogen (Fg)- and fibronectin (Fn)-binding sites on Fn-binding protein A (FnBPA), a cell surface protein from Staphylococcus aureus, are implicated in the initiation and persistence of infection. FnBPA contains a single Fg-binding site (that also binds elastin) and multiple Fn-binding sites. Here, we solved the structure of the N2N3 domains containing the Fg-binding site of FnBPA in the apo form and in complex with a Fg peptide. The Fg binding mechanism is similar to that of homologous bacterial proteins but without the requirement for “latch” strand residues. We show that the Fg-binding sites and the most N-terminal Fn-binding sites are nonoverlapping but in close proximity. Although Fg and a subdomain of Fn can form a ternary complex on an FnBPA protein construct containing a Fg-binding site and single Fn-binding site, binding of intact Fn appears to inhibit Fg binding, suggesting steric regulation. Given the concentrations of Fn and Fg in the plasma, this mechanism might result in targeting of S. aureus to fibrin-rich thrombi or elastin-rich tissues. PMID:24627488

  3. [Fibrinogen/fibrin-specific enzymes from copperhead (Agkistrodon halys halys) and cobra (Naja oxiana eichwald) snake venoms].

    PubMed

    Yunusova, E S; Sadykov, E S; Sultanalieva, N M; Shkinev, A V

    2016-03-01

    Ability of fractions of cobra's (Naja oxiana Eichwald) and copperhead snake's (Agkistrodon halys halys) venoms to hydrolyze fibrinogen/fibrin was studied. In cobra's snake a component with molecular mass of nearly 60 kDa was found to hydrolyze a-chain of fibrinogen but failed to hydrolyze casein/azocasein and fibrin. A fibrinogen-specific metalloproteinase, the enzyme was inhibited by EDTA. Cobra's venom reduced the mass of donor's fresh blood clots. The copperhead snake's venom and the fractions obtained by gel-filtration (HW-50) and ion exchange chromatography (DEAE-650) were found to hydrolyze casein/azocasein, a- and b-chains of fibrinogen/fibrin and donor's blood clots. The results from the study of the venom and proteolytically active fractions are the evidence for a thrombolytic potential in a copperhead snake's venom. PMID:27420616

  4. Impact of High-Normal Blood Pressure Measured in Emergency Room on Adverse Cardiac Events in Acute Myocardial Infarction

    PubMed Central

    Yoon, Nam Sik; Ahn, Youngkeun; Kim, Jong Hyun; Chae, Shung Chull; Kim, Young Jo; Hur, Seung Ho; Seong, In Whan; Hong, Taek Jong; Choi, Donghoon; Cho, Myeong Chan; Kim, Chong Jin; Seung, Ki Bae; Chung, Wook Sung; Jang, Yang Soo; Cho, Jeong Gwan; Park, Seung Jung

    2012-01-01

    Background and Objectives Prehypertension according to JNC7 is common and is associated with increased vascular mortality. The importance of management in high-normal blood pressure (BP) is underemphasized. Subjects and Methods We analyzed major adverse cardiac events (MACEs) in the Korea Acute Myocardial Infarction Registry in normal BP (group I) and high-normal BP (group II) patients. Results Among 14871 patients, 159 (61±12.3 years, 122 males) satisfied the study indication. Six-month and one-year clinical follow-up rate was 88.9% and 85.8%, respectively. Group I had 78 patients (60.9±12.4 years). Group II had 81 patients (61.6±12.5 years). Demographics of patients were not different between groups. Treatment strategy was not different. Initial Thrombolysis in Myocardial Infarction flow grade 0 was less frequent in group II (n=32, 47.1%) than in group I (n=16, 21.9%) (p=0.001). Successful intervention rate was not different between group II (93.8%) and group I (97.1%) (p=0.590). Six-month MACE occurred in 3 patients in group I (4.4%) and 10 in group II (15.6%) (p=0.031). Compared with normal BP, the odds ratio for patients with high-normal BP was 1.147 (p=0.045, 95% confidence interval 1.011-1.402) for 6-month MACE. Conclusion Even though high-normal BP patients had a better baseline clinical status, the prognosis was poorer than patients with normal BP. Therapeutic BP target goal for the patients with acute myocardial infarction should be <140/90 mm Hg, which is recommended in JNC7. PMID:22701132

  5. Interfacial adsorption of fibrinogen and its inhibition by RGD peptide: a combined physical study

    NASA Astrophysics Data System (ADS)

    Armstrong, Johanna; Salacinski, Henryk J.; Mu, Qingshan; Seifalian, Alex M.; Peel, Louise; Freeman, Neville; Holt, Cathy M.; Lu, Jian R.

    2004-07-01

    The Arg-Gly-Asp (RGD) peptide sequence is known as a cell recognition site for numerous adhesive proteins present in the extracellular matrix (ECM) and in blood. Whilst surface immobilized RGD groups enhance cell attachment, RGD components present in solution can effectively inhibit cell attachment by competing with endogenous ligands for the same recognition site. In contrast to the widely reported binding to cell integrin, this study demonstrates a new RGD feature: its inhibitive effect on fibrinogen adsorption. Through a combined analysis of spectroscopic ellipsometry, neutron reflection and dual polarization interferometry, we show that the kinetic process of fibrinogen adsorption as a model pro-coagulant at the silica/solution interface and in the absence of any cells can be substantially reduced by the addition of RGD in solution and that the extent of the reduction is dependent on the relative concentration of RGD.

  6. Canine intracranial meningiomas: Immunohistochemical evaluation of tissue factor, fibrin/fibrinogen and D-dimers.

    PubMed

    Font, Cristina; de la Fuente, Cristian; Pumarola, Martí; Blasco, Ester; Fernández, Francisco; Viu, Judit; Añor, Sònia

    2015-12-01

    The haemostatic system influences angiogenesis, cell growth and metastasis in solid tumours. The aim of this study was to investigate tissue factor (TF) expression, fibrin/fibrinogen and D-dimer deposition, as well as the occurrence of intravascular thrombosis (IVT) in canine intracranial meningiomas using immunohistochemistry. All but three (26/29) meningiomas expressed TF. TF immunolabelling was significantly higher in high-grade (grades II and III) than in low-grade (grade I) meningiomas. Fibrin/fibrinogen and D-dimer deposits were detected in all meningiomas and staining scores were statistically different between different meningioma grades. IVT was detected in 19/29 specimens, but no statistical differences were observed between different malignancy grades. In conclusion, the haemostatic system may be involved in meningioma pathobiology and may be a potential therapeutic target for canine meningiomas, as also suggested for human meningiomas. PMID:26526524

  7. Fibrin Clot Structure and Mechanics Associated with Specific Oxidation of Methionine Residues in Fibrinogen

    PubMed Central

    Weigandt, Katie M.; White, Nathan; Chung, Dominic; Ellingson, Erica; Wang, Yi; Fu, Xiaoyun; Pozzo, Danilo C.

    2012-01-01

    Using a combination of structural and mechanical characterization, we examine the effect of fibrinogen oxidation on the formation of fibrin clots. We find that treatment with hypochlorous acid preferentially oxidizes specific methionine residues on the α, β, and γ chains of fibrinogen. Oxidation is associated with the formation of a dense network of thin fibers after activation by thrombin. Additionally, both the linear and nonlinear mechanical properties of oxidized fibrin gels are found to be altered with oxidation. Finally, the structural modifications induced by oxidation are associated with delayed fibrin lysis via plasminogen and tissue plasminogen activator. Based on these results, we speculate that methionine oxidation of specific residues may be related to hindered lateral aggregation of protofibrils in fibrin gels. PMID:23283239

  8. Fibrinogen Concentrate Improves Survival During Limited Resuscitation of Uncontrolled Hemorrhagic Shock in a Swine Model

    PubMed Central

    White, Nathan J.; Wang, Xu; Liles, W. Conrad; Stern, Susan

    2014-01-01

    The purpose of this study was to evaluate the effect of fibrinogen concentrate, as a hemostatic agent, on limited resuscitation of uncontrolled hemorrhagic shock. We use a swine model of hemorrhagic shock with free bleeding from a 4mm aortic tear to test the effect of adding a one-time dose of fibrinogen concentrate given at the onset of limited fluid resuscitation. Immature female swine were anesthetized and subjected to catheter hemorrhage and aortic tear to induce uniform hemorrhagic shock. Animals (N=7 per group) were then randomized to receive either; 1. No fluid resuscitation (Neg Control), 2. Limited resuscitation in the form of two boluses of 10ml/kg of 6% hydroxyethyl starch solution (HEX) given 30 minutes apart, or 3. The same fluid regimen with one dose of 120mg/kg fibrinogen concentrate given with the first HEX bolus (FBG). Animals were then observed for a total of 6 hours with aortic repair and aggressive resuscitation with shed blood taking place at 3 hours. Survival to 6 hours was significantly increased with FBG (7/8, 86%) vs. HEX (2/7, 29%), and Neg Control (0/7, 0%) (FBG vs. HEX, Kaplan Meier LR p=0.035). Intraperitoneal blood loss adjusted for survival time was increased in HEX (0.4ml/kg/min) when compared to FBG (0.1mg/kg/min, p=0.047) and Neg Control (0.1ml/kg/min, p=0.041). Systemic and cerebral hemodynamics also showed improvement with FBG vs. HEX. Fibrinogen concentrate may be a useful adjunct to decrease blood loss, improve hemodynamics, and prolong survival during limited resuscitation of uncontrolled hemorrhagic shock. PMID:25337778

  9. Modification of fibrin network ultrastructure by Fab fragments specific for different domain of fibrinogen.

    PubMed

    Cierniewski, C S; Janiak, A; Wyroba, E

    1986-01-01

    Kinetics of inhibition of fibrin monomer polymerization produced by Fab fragments prepared from immunochemically purified monospecific antibodies to the surface epitopes of different domains of fibrinogen molecule has been correlated with electron microscopic observations of resulting specimens. Fab fragments prepared from anti FgD antisera were the most efficient inhibitors of thrombin-catalysed conversion of fibrinogen to fibrin; polymerization of fibrin monomers as detected spectrophotometrically was abolished at 2:1 molar ratio of anti FgD Fab fragments to fibra monomer. These Fab fragments acting as a steric hindrance of polymerization sites inhibited the first stage of fibrin monomer aggregation. Interaction of Fab fragments derived from antibodies specific for alpha 239-476 with corresponding segment of fibrinogen molecule resulted in a weak inhibition of fibrin monomer polymerization. However, fibrin obtained in the presence of these Fab fragments was significantly modified and showed no periodicity. This observation may suggest that anti alpha 239-476 Fab impaired the course of the second stage of fibrin monomer polymerization, i.e. lateral association of fibrin fibrils. PMID:2433859

  10. Overexpression, purification and preliminary crystallographic analysis of human M-ficolin fibrinogen-like domain

    SciTech Connect

    Tanio, Michikazu; Kondo, Shin; Sugio, Shigetoshi; Kohno, Toshiyuki

    2006-07-01

    Human M-ficolin fibrinogen-like domain has been overexpressed in P. pastoris, purified and crystallized. Diffraction data have been collected to 1.9 Å. Ficolins, which are comprised of a collagen-like domain and a fibrinogen-like domain, are a kind of pattern-recognition molecule for pathogens in the innate immunity system. To investigate the molecular mechanism of the discrimination between self and non-self by ficolins, human M-ficolin fibrinogen-like domain (FD1), which contains the ligand-binding site, was overexpressed in Pichia pastoris, purified and crystallized using the vapour-diffusion method at 293 K. The crystals belong to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 55.16, b = 117.45, c = 55.19 Å, β = 99.88°, and contain three molecules per asymmetric unit. An X-ray data set was collected to 1.9 Å resolution using synchrotron radiation at beamline BL24XU at the SPring-8 facility in Japan.

  11. The influence of residual water on the secondary structure and crystallinity of freeze-dried fibrinogen.

    PubMed

    Wahl, Verena; Scheibelhofer, Otto; Roessl, Ulrich; Leitgeb, Stefan; De Beer, Thomas; Khinast, Johannes

    2015-04-30

    The purpose of this work was to investigate the influence of water content on the secondary structure of a freeze-dried protein (fibrinogen) after a storage period of two weeks. To that end, attenuated reflectance Fourier transformed infrared (ATR-FTIR) and Raman spectra were generated and evaluated and the crystalline state of the fibrinogen bulks was determined via X-ray diffraction. First, a PCA (principal component analysis) of the spectral data was performed. While the α-helix and β-turn contents were increasing with the increasing water content, the β-sheet content was decreasing. A partial least squares (PLS) model was developed to correlate the mid-infrared and Raman spectral changes with the degree of crystallinity. The obtained R(2) value of 0.953 confirmed a correlation between changes in the secondary structure and crystallinity of the samples. The results demonstrated that the combined ATR-FTIR and Raman approach could be used to predict the crystalline state in freeze-dried fibrinogen products. PMID:25701629

  12. Characterization of the 5'-flanking region for the human fibrinogen beta gene.

    PubMed Central

    Huber, P; Dalmon, J; Courtois, G; Laurent, M; Assouline, Z; Marguerie, G

    1987-01-01

    To identify the possible regulatory sequences in the genetic expression of fibrinogen, a human genomic DNA library raised in lambda EMBL 4 phage was screened using cDNA probes coding for the A alpha, B beta and gamma chains of human fibrinogen. The entire fibrinogen locus was characterized and its organization analysed by means of hybridization and restriction mapping. Among the clones identified, a single recombinant lambda phage contained the beta gene and its 5'- and 3'-flanking regions. A 1.5 kb fragment of the immediate 5'-flanking region was sequenced and S1 mapping experiments revealed three transcription start points. Comparison of this sequence with that previously reported for the same region upstream from the human gamma gene revealed no significant homology which suggests that the potential promoting sequences of these genes are different. In contrast, comparison of the 5'-flanking regions of human and rat beta genes revealed a 142 bp sequence of 80% homology situated 16 bp upstream from the human beta gene. This highly conserved region may well represents a potential candidate for a regulatory sequence of the human beta gene. Images PMID:3029722

  13. An in vitro evaluation of fibrinogen and gelatin containing cryogels as dermal regeneration scaffolds.

    PubMed

    Allan, I U; Tolhurst, B A; Shevchenko, R V; Dainiak, M B; Illsley, M; Ivanov, A; Jungvid, H; Galaev, I Y; James, S L; Mikhalovsky, S V; James, S E

    2016-06-24

    Macroporous cryogels containing mixtures of two key components of the dermal extracellular matrix, fibrinogen and collagen-derived gelatin, were evaluated for use as dermal tissue regeneration scaffolds. The infiltration of human dermal fibroblasts into these matrices was quantitatively assessed in vitro using a combination of cell culture and confocal laser scanning microscopy. The extent of cellular infiltration, as measured by the number of cells per distance travelled versus time, was found to be positively correlated with the fibrinogen concentration of the cryogel scaffolds; a known potentiator of cell migration and angiogenesis within regenerating tissue. An analysis of the proteins expressed by infiltrating fibroblasts revealed that the cells that had migrated into the interior portion of the scaffolds expressed predominantly F-actin along their cytoplasmic stress fibres, whereas those present on the periphery of the scaffolds expressed predominantly α-smooth muscle actin, indicative of a nonmotile, myofibroblast phenotype associated with wound contraction. In conclusion, the cryogels produced in this study were found to be biocompatible and, by alteration of the fibrinogen content, could be rendered more amenable to cellular infiltration. PMID:27138753

  14. Identification and molecular characterisation of a fibrinogen binding protein from Streptococcus iniae.

    PubMed Central

    Baiano, Justice CF; Tumbol, Reiny A; Umapathy, Aarti; Barnes, Andrew C

    2008-01-01

    Background Binding of serum components by surface M-related proteins, encoded by the emm genes, in streptococci constitutes a major virulence factor in this important group of organisms. The present study demonstrates fibrinogen binding by S. iniae, a Lancefield non-typeable pathogen causing devastating fish losses in the aquaculture industry and an opportunistic pathogen of humans, and identifies the proteins involved and their encoding genes. Results Fibrinogen binding by S. iniae significantly reduced respiratory burst activity of barramundi peritoneal macrophages in primary cultures compared to BSA-treated or untreated controls, indicating a potentially important role for fibrinogen binding cell-surface proteins in avoiding phagocytic attack in fish. We describe a novel emm-like gene, simA, encoding a 57 kDa fibrinogen binding M-like protein in S. iniae. These SiM proteins and their corresponding tetrameric structures from some sequevar types (~230 kDa) bound fibrinogen in Western blots. simA was most closely related (32% identity) to the demA gene of S. dysgalactiae. Genome walking and sequencing determined the genetic organization of the simA region had similarities to the mgrC regulon in GCS and to S. uberis. Moreover, a putative multigene regulator, mgx was orientated in the opposite direction to the simA gene in common with S. uberis, but contrary to findings in GAS and GCS. In GAS, diversity among emm-genes and consequent diversity of their M-related proteins results in substantial antigenic variation. However, an extensive survey of S. iniae isolates from diverse geographic regions and hosts revealed only three variants of the gene, with one sequevar accounting for all but two of the 50 isolates analysed. Conclusion These proteins play a role in avoiding oxidative attack by phagocytic cells during infection of fish by S. iniae, but genetic diversity amongst these key surface proteins has not yet arisen. This lack of diversity coupled with a functional

  15. Thermodynamics of native protein/foreign surface interactions. IV. Calorimetric and microelectrophoretic study of human fibrinogen sorption onto glass and LTI-carbon.

    PubMed

    Chiu, T H; Nyilas, E; Lederman, D M

    1976-01-01

    1. According to a working hypothesis put forward in the previous papers of this series2-4, the initial phases of native blood/foreign surface interactions have been considered within the framework of a physicochemical model of contact activation at the molecular level. The salient features of this hypothesis are: a) the arrival and adsorption of native plasma proteins on a contact surface overwhelmingly precedes that of the cellular blood components; b) the interaction energy that arises between a particular foreign surface and native plasma proteins settling on it, is a characteristic quantity depending upon the effective surface molecular structure as well as the nature of the proteins; c) the "intensity" of native protein/foreign surface interactions can be treated in terms of thermodynamic quantities since these energy terms are independent of the type of forces acting between protein and surface; and d) depending upon the degree to which the adsorption of a native protein is thermodynamically favored by enthalpy and/or entropy factors, the interaction energy can be utilized to induce conformational changes of varying degree in the sorbed protein. 2. Using glass and low temperature isotropic (LTI) carbon adsorbents, i.e., a known procoagulant and a relevant biomaterial, respectively, the adsorption properties and the potential surface-induced conformational changes of high-purity native human fibrinogen (clottability greater than or equal to 92%) were studied, at 25 degrees C, by 3 independent methods. In all of the experiments performed, a) both adsorbents were employed in the form of particles less than or equal to 1.0 mu representing specific surface areas of 9.85 M2/Gm and 27.7 (nominal) M2/Gm for the glass and LTI-carbon powders, respectively, and b) the fibrinogen was absorbed from a standaridized buffer (pH = 7.2, ionic strength 0.05) using the same fixed surface area/protein solution volume ratio with a given adsorbent. 3. The 25 degrees C adsorption

  16. Histamine-induced airway mucosal exudation of bulk plasma and plasma-derived mediators is not inhibited by intravenous bronchodilators.

    PubMed

    Svensson, C; Alkner, U; Pipkorn, U; Persson, C G

    1994-01-01

    Experimental data suggest the possibility that common bronchodilators, such as the xanthines and beta 2-adrenoceptor agonists, may produce microvascular anti-permeability effects in the subepithelial microcirculation of the airways. In this study, we have examined the effect of bronchodilators given intravenously on exudation of different-sized plasma proteins (albumin and fibrinogen) and the generation of plasma-derived peptides (bradykinins) in human nasal airways challenged with histamine. In a double-blind, crossover, placebo-controlled and randomised trial, 12 normal volunteers were given i.v.infusions of terbutaline sulphate, theophylline and enprofylline to produce therapeutic drug levels. The effect of topical nasal provocation with histamine was closely followed by frequently nasal lavage with saline. The lavage fluid levels of albumin, fibrinogen and bradykinins increased significantly after each histamine provocation. The ratio of albumin-to-fibrinogen in plasma and the lavage fluid was 24 and 56, respectively, indicating that topical histamine provocation induced a largely non-sieved flux of macromolecules across the endothelial-epithelial barriers. The systemically administered drugs did not affect the nasal symptoms (sneezing, secretion and blockage), nor did they significantly reduce the levels of plasma proteins and plasma-derived mediators in the nasal lavage fluids. The present data suggest that systemic xanthines and beta 2-adrenoceptor agonists, at clinically employed plasma levels, may not affect the microvascular (and epithelial) exudative permeability and the bradykinin forming capacity of human airways. PMID:8005188

  17. Associations of the β-Fibrinogen Hae III and Factor XIII Val34Leu Gene Variants with Venous Thrombosis

    PubMed Central

    Cushman, Mary; Cornell, Alexandra; Folsom, Aaron R.; Wang, Lu; Tsai, Michael Y.; Polak, Joseph; Tang, Zhonghua

    2008-01-01

    Introduction The factor XIII Val34Leu (100 G→T) and β-fibrinogen Hae III (-455 G→A) gene variants have been associated with reduced risk of venous thrombosis, but not in all studies. Methods We investigated the associations of these polymorphisms with risk of venous thrombosis in a prospective, population-based study of 21,680 men and women aged 45–100 years at enrollment. Factor XIII 100 G/T and β-fibrinogen -455 G/A were analyzed on stored DNA from 511 thrombosis cases and 1028 control subjects without thrombosis during follow up. Results The β-fibrinogen A allele was present in 24.4% of cases and 32.3% of controls. Compared to GG subjects, the age, race, and sex adjusted odds ratio (OR) of venous thrombosis was 0.77 (95% CI 0.59–0.99) for GA subjects, and 0.60 (95% CI 0.31–1.16) for AA subjects. The adjusted OR of thrombosis associated with factor XIII 100 G/T was 1.01 (95% CI 0.81–1.26) for GT subjects and 0.45 (95% CI 0.44–1.19) for TT subjects, compared to GG. For both genotypes, ORs of thrombosis were similar in whites and non-whites, although there were no non-white fibrinogen AA cases. β-Fibrinogen -455GA or AA attenuated the thrombosis risk associated with obesity (from 2.14 to 1.25) and factor V Leiden (from 3.89 to 2.36). Conclusions β-fibrinogen -455 G/A, but not factor XIII 100 G/T, was associated with a lower risk of venous thrombosis in this general population sample. β-Fibrinogen -455A may attenuate the increased thrombosis risk associated with obesity or factor V Leiden. PMID:17582472

  18. Sleep and biomarkers in the English Longitudinal Study of Ageing: associations with C-reactive protein, fibrinogen, dehydroepiandrosterone sulfate and hemoglobin.

    PubMed

    Jackowska, Marta; Kumari, Meena; Steptoe, Andrew

    2013-09-01

    Sleep duration and quality are associated with adverse physical health outcomes. The mechanisms are not well understood, and little is known about associations with biomarkers in older population cohorts. This study assessed cross-sectional associations between self-reported sleep measures and biomarkers in a representative sample of British people aged 50 years and above. Participants were 6465 men and women aged 50-99 years from the English Longitudinal Study of Ageing (ELSA). Associations of sleep duration and sleep disturbance with C-reactive protein (CRP), fibrinogen, dehydroepiandrosterone sulfate (DHEAS) and hemoglobin were analyzed, adjusting for age, wealth, body mass index (BMI), smoking, physical activity, limiting long-standing illness and depressive symptoms. In men, long sleep duration (OR: 1.50, 1.05-2.14) and greater sleep disturbance (OR: 1.29, C.I. 1.05-1.59) were associated with raised CRP levels, while long sleep was also related to raised plasma fibrinogen (P=0.001). DHEAS levels were lower among men reporting more sleep disturbances (P=0.016), but were not related to sleep duration. Sleep duration (P=0.015) and sleep disturbance (P=0.039) were associated with lower hemoglobin levels, and anemia was more prevalent among men with disturbed sleep (OR: 1.73, C.I. 1.13-2.65). In women more disturbed sleep was associated with greater likelihood of anemia (OR: 1.59, C.I. 1.02-2.46), but there was no relationship between sleep disturbance or duration with other biomarkers. This study suggests that self-reported sleep duration and disturbance are related to biological risk factors in community-dwelling older adults, with different associations being present in men and women. A better understanding of these relationships using longitudinal cohort studies will broaden our understanding of the mechanisms relating sleep indices and ill health in advancing age. PMID:23352806

  19. Ablation of matrix metalloproteinase-9 gene decreases cerebrovascular permeability and fibrinogen deposition post traumatic brain injury in mice.

    PubMed

    Muradashvili, Nino; Benton, Richard L; Saatman, Kathryn E; Tyagi, Suresh C; Lominadze, David

    2015-04-01

    Traumatic brain injury (TBI) is accompanied with enhanced matrix metalloproteinase-9 (MMP-9) activity and elevated levels of plasma fibrinogen (Fg), which is a known inflammatory agent. Activation of MMP-9 and increase in blood content of Fg (i.e. hyperfibrinogenemia, HFg) both contribute to cerebrovascular disorders leading to blood brain barrier disruption. It is well-known that activation of MMP-9 contributes to vascular permeability. It has been shown that at an elevated level (i.e. HFg) Fg disrupts blood brain barrier. However, mechanisms of their actions during TBI are not known. Mild TBI was induced in wild type (WT, C57BL/6 J) and MMP-9 gene knockout (Mmp9(-/-)) homozygous, mice. Pial venular permeability to fluorescein isothiocyanate-conjugated bovine serum albumin in pericontusional area was observed 14 days after injury. Mice memory was tested with a novel object recognition test. Increased expression of Fg endothelial receptor intercellular adhesion protein-1 and formation of caveolae were associated with enhanced activity of MMP-9 causing an increase in pial venular permeability. As a result, an enhanced deposition of Fg and cellular prion protein (PrP(C)) were found in pericontusional area. These changes were attenuated in Mmp9(-/-) mice and were associated with lesser loss of short-term memory in these mice than in WT mice. Our data suggest that mild TBI-induced increased cerebrovascular permeability enhances deposition of Fg-PrP(C) and loss of memory, which is ameliorated in the absence of MMP-9 activity. Thus, targeting MMP-9 activity and blood level of Fg can be a possible therapeutic remedy to diminish vasculo-neuronal damage after TBI. PMID:24771110

  20. Ablation of matrix metalloproteinase-9 gene decreases cerebrovascular permeability and fibrinogen deposition post traumatic brain injury in mice

    PubMed Central

    Muradashvili, Nino; Benton, Richard L.; Saatman, Kathryn E.; Tyagi, Suresh C.; Lominadze, David

    2014-01-01

    Traumatic brain injury (TBI) is accompanied with enhanced matrix metalloproteinase-9 (MMP-9) activity and elevated levels of plasma fibrinogen (Fg), which is a known inflammatory agent. Activation of MMP-9 and increase in blood content of Fg (i.e. hyperfibrinogenemia, HFg) both contribute to cerebrovascular disorders leading to blood brain barrier disruption. It is well-known that activation of MMP-9 contributes to vascular permeability. It has been shown that at an elevated level (i.e. HFg) Fg disrupts blood brain barrier. However, mechanisms of their actions during TBI are not known. Mild TBI was induced in wild type (WT, C57BL/6J) and MMP-9 gene knockout (Mmp9−/−) homozygous, mice. Pial venular permeability to fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) in pericontusional area was observed 14 days after injury. Mice memory was tested with a novel object recognition test. Increased expression of Fg endothelial receptor intercellular adhesion protein-1 and formation of caveolae were associated with enhanced activity of MMP-9 causing an increase in pial venular permeability. As a result, an enhanced deposition of Fg and cellular prion protein (PrPC) were found in pericontusional area. These changes were attenuated in Mmp9−/− mice and were associated with lesser loss of short-term memory in these mice than in WT mice. Our data suggest that mild TBI-induced increased cerebrovascular permeability enhances deposition of Fg-PrPC and loss of memory, which is ameliorated in the absence of MMP-9 activity. Thus, targeting MMP-9 activity and blood level of Fg can be a possible therapeutic remedy to diminish vasculo-neuronal damage after TBI. PMID:24771110

  1. A fibrinogen-related protein identified from hepatopancreas of crayfish is a potential pattern recognition receptor.

    PubMed

    Chen, Qiming; Bai, Suhua; Dong, Chaohua

    2016-09-01

    Fibrinogen-related protein (FREP) family is a large group of proteins containing fibrinogen-like (FBG) domain and plays multiple physiological roles in animals. However, their immune functions in crayfish are not fully explored. In the present study, a novel fibrinogen-like protein (designated as PcFBN1) was identified and characterized from hepatopancreas of red swamp crayfish Procambarus clarkii. The cDNA sequence of PcFBN1 contains an open reading frame (ORF) of 1353 bp encoding a protein of 450 amino acids. Sequence and structural analysis indicated that PcFBN1 contains an FBG domain in C-terminal and a putative signal peptide of 19 amino acids in N-terminal. Semi-quantitative PCR revealed that the main expression of PcFBN1 was observed in hepatopancreas and hemocyte. Temporal expression analysis exhibited that PcFBN1 expression could be significantly induced by heat-killed Aeromonas hydrophila. Tissue distribution and temporal change of PcFBN1 suggested that PcFBN1 may be involved in immune responses of red swamp crayfish. Recombinant PcFBN1 protein binds and agglutinates both gram-negative bacteria Escherichia coli and gram-positive bacteria Micrococcus lysodeikticus. Moreover, binding and agglutination is Ca(2+) dependent. Further analysis indicated that PcFBN1 recognizes some acetyl group-containing substance LPS and PGN. RNAi experiment revealed that PcFBN1 is required for bacterial clearance and survival from A. hydrophila infection. Reduction of PcFBN1 expression significantly decreased the survival and enhanced the number of A. hydrophila in the hemolymph. These results indicated that PcFBN1 plays an important role in the innate immunity of red swamp crayfish as a potential pattern recognition receptor. PMID:27417229

  2. A family of cell-adhering peptides homologous to fibrinogen C-termini

    SciTech Connect

    Levy-Beladev, Liron; Levdansky, Lilia; Gaberman, Elena; Friedler, Assaf; Gorodetsky, Raphael

    2010-10-08

    Research highlights: {yields} Cell-adhesive sequences homologous to fibrinogen C-termini exist in other proteins. {yields} The extended homologous cell-adhesive C-termini peptides family is termed Haptides. {yields} In membrane-like environment random coiled Haptides adopt a helical conformation. {yields} Replacing positively charged residues with alanine reduces Haptides activity. -- Abstract: A family of cell-adhesive peptides homologous to sequences on different chains of fibrinogen was investigated. These homologous peptides, termed Haptides, include the peptides C{beta}, preC{gamma}, and C{alpha}E, corresponding to sequences on the C-termini of fibrinogen chains {beta}, {gamma}, and {alpha}E, respectively. Haptides do not affect cell survival and rate of proliferation of the normal cell types tested. The use of new sensitive assays of cell adhesion clearly demonstrated the ability of Haptides, bound to inert matrices, to mediate attachment of different matrix-dependent cell types including normal fibroblasts, endothelial, and smooth muscle cells. Here we present new active Haptides bearing homologous sequences derived from the C-termini of other proteins, such as angiopoietin 1 and 2, tenascins C and X, and microfibril-associated glycoprotein-4. The cell adhesion properties of all the Haptides were found to be associated mainly with their 11 N-terminal residues. Mutated preC{gamma} peptides revealed that positively charged residues account for their attachment effect. These results suggest a mechanism of direct electrostatic interaction of Haptides with the cell membrane. The extended Haptides family may be applied in modulating adhesion of cells to scaffolds for tissue regeneration and for enhancement of nanoparticulate transfection into cells.

  3. Characterization of peptides cleaved by plasmin from the C-terminal polymerization domain of human fibrinogen.

    PubMed

    Southan, C; Thompson, E; Panico, M; Etienne, T; Morris, H R; Lane, D A

    1985-10-25

    The C-terminal region of the fibrinogen gamma chain is known to participate in several functional interactions including fibrin polymerization. This part of the molecule is retained on the gamma chain of fragment D (FgD) when fibrinogen is digested by plasmin in the presence of calcium to produce the fragment D-fragment E (FgD X FgE) complex but is lost if FgD is prepared in the absence of calcium. In an attempt to characterize the C-terminal polymerization domain we have used three techniques to examine this further degradation of FgD following the addition of EDTA and plasmin. Analysis of the digestion by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a progressive cleavage of the gamma chain to two small remnants. The polymerization-inhibitory activity of the whole digest was studied using acid-solubilized fibrin. A progressive loss of inhibitory activity was associated with gamma chain shortening, reaching greater than a 120-fold reduction at the end of digestion. The cleavage of peptides was followed by reverse-phase high performance liquid chromatography and the release of a characteristic peptide triplet was associated with gamma chain cleavage. Manual sequencing, amino acid analysis, and fast atom bombardment mass spectrometry established the three peptides as gamma 303-356, 357-373, and 374-405. These peptides have sequences in common with those peptides recently reported by other investigators to be potent polymerization inhibitors. However, when a mixture of the three peptides was added in a 200-fold molar excess to polymerizing fibrin, no inhibitory activity could be demonstrated. It is concluded that the C-terminal polymerization domain of fibrinogen may be an extended region which includes the sequence gamma 303-405, when this is contiguous with the remainder of the gamma chain. PMID:2932434

  4. Differential effects of insulin deficiency on albumin and fibrinogen synthesis in humans.

    PubMed Central

    De Feo, P; Gaisano, M G; Haymond, M W

    1991-01-01

    Insulin deficiency decreases tissue protein synthesis, albumin mRNA concentration, and albumin synthesis in rats. In contrast, insulin deficiency does not change, or, paradoxically, increases estimates of whole body protein synthesis in humans. To determine if such estimates of whole body protein synthesis could obscure potential differential effects of insulin on the synthetic rates of individual proteins, we determined whole body protein synthesis and albumin and fibrinogen fractional synthetic rates using 5-h simultaneous infusions of [14C]leucine and [13C]bicarbonate, in six type 1 diabetics during a continuous i.v. insulin infusion (to maintain euglycemia) and after short-term insulin withdrawal (12 +/- 2 h). Insulin withdrawal increased (P less than 0.03) whole body proteolysis by approximately 35% and leucine oxidation by approximately 100%, but did not change 13CO2 recovery from NaH13CO3 or estimates of whole body protein synthesis (P = 0.21). Insulin deficiency was associated with a 29% decrease (P less than 0.03) in the albumin fractional synthetic rate but a 50% increase (P less than 0.03) in that of fibrinogen. These data provide strong evidence that albumin synthesis in humans is an insulin-sensitive process, a conclusion consistent with observations in rats. The increase in fibrinogen synthesis during insulin deficiency most likely reflects an acute phase protein response due to metabolic stress. These data suggest that the absence of changes in whole body protein synthesis after insulin withdrawal is the result of the summation of differential effects of insulin deficiency on the synthesis of specific body proteins. PMID:1909352

  5. Human cardiomyocyte interaction with electrospun fibrinogen/gelatin nanofibers for myocardial regeneration.

    PubMed

    Balasubramanian, Preethi; Prabhakaran, Molamma P; Kai, Dan; Ramakrishna, Seeram

    2013-01-01

    Myocardial infarction is the major cause of death in many industrialized nations as it leads to end-stage heart failure. Tissue engineering (TE) approaches for treatment of the infarcted tissue have gained huge attention over the recent years and research in this direction mainly aims for the optimization of a biomaterial scaffold with suitable cell source for tissue regeneration. In this regard, we fabricated completely natural polymeric scaffolds using fibrinogen and gelatin in two different weight ratios and performed cross-linking [Fib/Gel(1:4)-CL; Fib/Gel(2:3)-CL] while cross-linked fibrinogen scaffolds were used as the control. The fiber diameters of the fabricated scaffolds were obtained in the range of 150-300 nm. Chemical characterization of the scaffolds confirmed the presence of both the proteins and showed the absence of any chemical reactions between them. The tensile strength and the stiffness values of Fib/Gel(1:4)-CL matrices were found to be 0.0125 and 0.46 MPa, respectively, which were much similar to the innate properties of the native myocardium. Cell culture studies using human cardiomyocytes revealed higher cell proliferation on Fib/Gel(1:4)-CL scaffolds compared to cell proliferation on Fib/Gel(2:3)-CL scaffolds, which was even higher than the cell proliferation on cross-linked fibrinogen scaffolds. Moreover, the cardiomyocytes seeded on composite substrates expressed the typical functional cardiac proteins such as alpha-actinin, troponin I, connexin-43, and myosin heavy chain, and could be potential for application in cardiac TE. PMID:23611504

  6. Air Pollution and Inflammation (Interleukin-6, C-Reactive Protein, Fibrinogen) in Myocardial Infarction Survivors

    PubMed Central

    Rückerl, Regina; Greven, Sonja; Ljungman, Petter; Aalto, Pasi; Antoniades, Charalambos; Bellander, Tom; Berglind, Niklas; Chrysohoou, Christina; Forastiere, Francesco; Jacquemin, Bénédicte; von Klot, Stephanie; Koenig, Wolfgang; Küchenhoff, Helmut; Lanki, Timo; Pekkanen, Juha; Perucci, Carlo A.; Schneider, Alexandra; Sunyer, Jordi; Peters, Annette

    2007-01-01

    Background Numerous studies have found that ambient air pollution has been associated with cardiovascular disease exacerbation. Objectives Given previous findings, we hypothesized that particulate air pollution might induce systemic inflammation in myocardial infarction (MI) survivors, contributing to an increased vulnerability to elevated concentrations of ambient particles. Methods A prospective longitudinal study of 1,003 MI survivors was performed in six European cities between May 2003 and July 2004. We compared repeated measurements of interleukin 6 (IL-6), fibrinogen, and C-reactive protein (CRP) with concurrent levels of air pollution. We collected hourly data on particle number concentrations (PNC), mass concentrations of particulate matter (PM) < 10 μm (PM10) and < 2.5 μm (PM2.5), gaseous pollutants, and meteorologic data at central monitoring sites in each city. City-specific confounder models were built for each blood marker separately, adjusting for meteorology and time-varying and time-invariant covariates. Data were analyzed with mixed-effects models. Results Pooled results show an increase in IL-6 when concentrations of PNC were elevated 12–17 hr before blood withdrawal [percent change of geometric mean, 2.7; 95% confidence interval (CI), 1.0–4.6]. Five day cumulative exposure to PM10 was associated with increased fibrinogen concentrations (percent change of arithmetic mean, 0.6; 95% CI, 0.1–1.1). Results remained stable for smokers, diabetics, and patients with heart failure. No consistent associations were found for CRP. Conclusions Results indicate an immediate response to PNC on the IL-6 level, possibly leading to the production of acute-phase proteins, as seen in increased fibrinogen levels. This might provide a link between air pollution and adverse cardiac events. PMID:17637925

  7. Autophagy-enhancing drug carbamazepine diminishes hepatocellular death in fibrinogen storage disease.

    PubMed

    Puls, Florian; Goldschmidt, Imeke; Bantel, Heike; Agne, Clemens; Bröcker, Verena; Dämmrich, Maximilian; Lehmann, Ulrich; Berrang, Jens; Pfister, Eva-Doreen; Kreipe, Hans Heinrich; Baumann, Ulrich

    2013-09-01

    Fibrinogen storage disease (FSD) is a rare autosomal-dominant hereditary disorder characterized by hypofibrinogenemia and accumulation of fibrinogen aggregates within the hepatocellular endoplasmatic reticulum (ER). Some FSD patients present with elevated amino-transferases and fibrosis/cirrhosis similar to alpha-1-antitrypsin deficiency (ATD), also an ER storage disease. Pharmacological stimulation of autophagy has been shown to mediate clearance of protein aggregates and halt progression of liver fibrosis in in vivo models of ATD. Our aim was to evaluate the presence of autophagy and a possible response to autophagy-enhancing therapy in patients with FSD. Hepatic fibrosis was assessed by transient elastography in 2 newly identified FSD families with fibrinogen Aguadilla and Brescia mutations, encompassing 8 affected members. Available liver biopsies were assessed for autophagy. Two patients, who had had elevated alanine amino-transaminase levels (2-5 above upper limit of normal), were treated with the autophagy enhancer carbamazepine (CBZ). Transient elastography did not show evidence of significant fibrosis in any affected family members. Quantitative electron microscopy of one patient showed a 5.15-fold increase of late stage autophagocytic vacuoles compared to control livers. CBZ at low anticonvulsive treatment levels led to rapid normalization of alanine-aminotransferase and decrease of caspase-cleaved and uncleaved cytokeratin-18 fragments (M30 and M65). These effects reversed after discontinuation of treatment. Response to CBZ may be mediated by pharmacologically enhanced autophagy resulting in reduction of aggregate-related toxicity in FSD. These results suggest clinical applicability of pharmacological stimulation of autophagy in FSD, but potentially also in other related disorders. PMID:23707368

  8. Control of Integrin αIIbβ3 Outside-In Signaling and Platelet Adhesion by Sensing the Physical Properties of Fibrin(ogen) Substrates†

    PubMed Central

    Podolnikova, Nataly P.; Yermolenko, Ivan S.; Fuhrmann, Alexander; Lishko, Valeryi K.; Magonov, Sergei; Bowen, Benjamin; Enderlein, Joerg; Podolnikov, Andriy V.; Ros, Robert; Ugarova, Tatiana P.

    2015-01-01

    The physical properties of substrates are known to control cell adhesion via integrin-mediated signaling. Fibrin and fibrinogen, the principal components of hemostatic and pathological thrombi, may represent biologically relevant substrates whose variable physical properties control adhesion of leukocytes and platelets. In our previous work, we have shown that binding of fibrinogen to the surface of fibrin clot prevents cell adhesion by creating an antiadhesive fibrinogen layer. Furthermore, fibrinogen immobilized on various surfaces at high density supports weak cell adhesion whereas at low density it is highly adhesive. To explore the mechanism underlying differential cell adhesion, we examined the structural and physical properties of surfaces prepared by deposition of various concentrations of fibrinogen using atomic force microscopy and force spectroscopy. Fibrinogen deposition at high density resulted in an aggregated multilayered material characterized by low adhesion forces. In contrast, immobilization of fibrinogen at low density produced a single layer in which molecules were directly attached to the solid surface, resulting in higher adhesion forces. Consistent with their distinct physical properties, low- but not high-density fibrinogen induced strong αIIbβ3-mediated outside-in signaling in platelets, resulting in their spreading. Moreover, while intact fibrin gels induced strong signaling in platelets, deposition of fibrinogen on the surface of fibrin resulted in diminished cell signaling. The data suggest that deposition of a multilayered fibrinogen matrix prevents stable cell adhesion by modifying the physical properties of surfaces, which results in reduced force generation and insufficient signaling. The mechanism whereby circulating fibrinogen alters adhesive properties of fibrin clots may have important implications for control of thrombus formation and thrombogenicity of biomaterials. PMID:19929007

  9. [Fibrinogen--acute phase protein as a marker of immunological process as atherosclerosis].

    PubMed

    Rajtari, Renata; Kloch, Małgorzata; Kiec-Wilk, Beata; Kolasińska-Kloch, Władysława

    2005-01-01

    The most important CAD risk factors are: smoking, high level of LDL-cholesterol and low level of HDL-cholesterol, hypertriglyceridemia, diabetes, obesity, hypertension, men sex, age over 45 in men and over 55 in women. Carl von Rokitański was the first who suggested the role of thrombosis and fibrynolisis in the development of atherosclerosis and was the author of thrombolic theory. The recently studies show that atherosclerosis is an immuno-inflamatory process. Fibrinogen as an acute phase protein is a new marker of ischemic heart disease and its role in atherosclerosis needs further investigations. PMID:17037285

  10. Mechanisms of fibrinogen adsorption at the silica substrate determined by QCM-D measurements.

    PubMed

    Kubiak, Katarzyna; Adamczyk, Zbigniew; Wasilewska, Monika

    2015-11-01

    Adsorption kinetics of fibrinogen at a silica substrate was thoroughly studied in situ using the QCM-D method. Because of low dissipation, the Sauerbrey's equation was used for calculating the wet mass per unit area (wet coverage of the protein). Measurements were done for various bulk suspension concentrations, flow rates and pHs. These experimental data were compared with the theoretical dry coverage data derived from the solution of the mass transfer equation. In this way, the hydration functions and water factors of fibrinogen monolayers were quantitatively evaluated for various pHs. In the case of pH 7.4 and ionic strength of 0.15 M, the hydration function changed from 0.75 to 0.6 for the dry coverage Γ(d) equal to 0 and 4 mg m(-2), respectively. Interestingly, for pH 7.4 and 4.5 (ionic strength of 10(-2) M) a minimum of the hydration function appeared at Γ(d) ca. 2 mg m(-2). Analytical polynomial expressions were formulated for the interpolation of the experimental results. By using the hydration functions, the fibrinogen adsorption/desorption runs derived from QCM-D measurements were converted to the Γ(d) vs. the time relationships. This allowed to precisely determine the maximum coverage that varied between 1.2 mg m(-2) at pH 3.5 and 4.2 mg m(-2) at pH 7.4 for ionic strength of 0.15 M. These results agree with theoretical modeling and previous experimental data derived by using ellipsometry, OWLS and TIRF. Various fibrinogen adsorption mechanisms were revealed by exploiting the maximum coverage data whose validity was also confirmed by the dissipation vs. the dry mass relationships. Beside significance to basic science, these results enable to develop a robust technique, based on the QCM-D measurements, suitable for precisely determining the dry mass of protein monolayers adsorbed under various physicochemical conditions. PMID:26209759

  11. The conversion of fibrinogen to fibrin. XIII. Dissolution of fibrin and inhibition of clotting by various neutral salts.

    PubMed

    SHULMAN, S; KATZ, S; FERRY, J D

    1953-07-01

    1. Fibrin clots prepared in the absence of calcium can be dissolved in solutions of lithium chloride and bromide and sodium bromide and iodide, as well as of guanidine hydrochloride and urea. These salts do not denature fibrinogen under the same conditions of concentration, temperature, and time. Sedimentation experiments on the fibrin solutions show in each case a single sharp peak with a sedimentation constant close to that of fibrinogen. 2. At lower concentrations, these salts inhibit the clotting of fibrinogen by thrombin, but in the case of lithium bromide and sodium iodide, at least, allow an intermediate polymer to accumulate whose sedimentation constant is close to that of the polymer observed in systems inhibited by hexamethylene glycol or urea. PMID:13069679

  12. /sup 111/In-platelet and /sup 125/I-fibrinogen deposition in the lungs in experimental acute pancreatitis

    SciTech Connect

    Goulbourne, I.A.; Watson, H.; Davies, G.C.

    1987-12-01

    An experimental model of acute pancreatitis in rats has been used to study intrapulmonary /sup 125/I-fibrinogen and /sup 111/In-platelet deposition. Pancreatitis caused a significant increase in wet lung weight compared to normal, and this could be abolished by heparin or aspirin pretreatment. /sup 125/I-fibrinogen was deposited in the lungs of animals to a significantly greater degree than in controls (P less than 0.01). /sup 125/I-fibrinogen deposition was reduced to control levels by pretreatment with aspirin or heparin (P less than 0.05). The uptake of radiolabeled platelets was greater in pancreatitis than in controls (P less than 0.001). Pancreatitis appears to be responsible for platelet entrapment in the lungs. Platelet uptake was reduced by heparin treatment but unaffected by aspirin therapy.

  13. Surveillance of deep vein thrombosis in asymptomatic total hip replacement patients. Impedance phlebography and fibrinogen scanning versus roentgenographic phlebography

    SciTech Connect

    Paiement, G.; Wessinger, S.J.; Waltman, A.C.; Harris, W.H.

    1988-03-01

    Nine hundred thirty-seven limbs in 537 patients over the age of 39 years who underwent total hip replacement were studied by roentgenographic phlebography, cuff-impedance phlebography, and iodine-125 fibrinogen scanning. Cuff-impedance phlebography had a sensitivity of only 12.3 percent for thigh thrombi. Fibrinogen scanning had a sensitivity of only 59.1 percent for calf thrombi and 13.7 percent for thigh thrombi. The combined use of the two methods resulted in only a 23.2 percent sensitivity for thigh thrombi and an overall sensitivity of 47.4 percent. We have concluded that in asymptomatic patients, in contrast with symptomatic patients, the combination of cuff-impedance phlebography and fibrinogen scanning is not an effective screening method.

  14. Effect of therapeutic plasma exchange on coagulation parameters in patients on warfarin.

    PubMed

    Zantek, Nicole D; Morgan, Shanna; Zantek, Paul F; Mair, David C; Bowman, Robert J; Aysola, Agnes

    2014-04-01

    Therapeutic plasma exchange (TPE) without plasma replacement results in coagulation factor removal. Warfarin decreases the activity of vitamin K dependent coagulation factors. The combined effect of TPE and warfarin on the coagulation system has not been studied. A prospective, observational study was conducted in patients undergoing TPE while on warfarin. One plasma volume TPEs were performed on the COBE Spectra Apheresis System (Terumo BCT, Lakewood, CO) with 5% albumin. International normalized ratio (INR), fibrinogen, and factor II activity were obtained pre and post procedure. Eight patients underwent 121 TPEs that met study criteria with pre and post data. The average pre values were INR 2.09 ± 0.58, fibrinogen 263 ± 76 mg/dl, and factor II 29 ± 16% and the average post values were INR 4.12 ± 1.44, fibrinogen 105 ± 31 mg/dl, and factor II 13 ± 7%. The pre-INR was ≥2.00 for 55% of TPEs. The pre value (Y0 ) predicts the post value (Y) by the following equations Y = -0.54 + 2.21Y0 , Y =12.10 + 0.35Y0, and Y =1.83 + 0.39Y0 for INR, fibrinogen, and factor II respectively. In conclusion, pre procedure laboratory values can predict the post laboratory values for patients on warfarin receiving single plasma volume TPE with albumin replacement. The post-INR is approximately twice the pre-INR. At normal and mildly elevated pre-INR, the effect of TPE on the INR is less marked. A single plasma volume TPE decreases the plasma level by ∼65% for fibrinogen and 60% for factor II. PMID:24000079

  15. Expression of binding of plasminogen, thrombospondin, vitronectin, and fibrinogen, and adhesive properties by Escherichia coli strains isolated from patients with colonic diseases.

    PubMed Central

    Shen, W; Steinrück, H; Ljungh, A

    1995-01-01

    Escherichia coli strains isolated from patients with colonic disorders (n = 27) and strains isolated from the rectal mucosa of healthy subjects (n = 24) were compared with respect to expression of cell surface hydrophobicity, carriage of intestinal virulence factors, adhesion to tissue culture cells, and expression of binding of extracellular matrix proteins and plasma proteins. Strains isolated from patients with colonic disease did not express a more hydrophobic cell surface than strains from healthy subjects. Few strains from both groups carried genes encoding for recognised virulence factors of E coli. Only one strain, carrying the eae gene induced actin polymerisation in tissue culture cells. Strains from patients with colonic diseases adhered to HT29 cells, which are of intestinal origin, to a higher extent than E coli from healthy subjects. Significantly more strains from patients with colonic disorders than E coli from healthy subjects expressed binding of fibronectin, collagens, laminin, vitronectin, plasminogen, throbospondin, and fibrinogen. Expression of binding of these proteins may influence the pathogenesis of colonic disease by mediating binding to ulcerated tissue, preventing complement induced lysis of bacteria and by exerting proteolytic activity. There was no correlation between serotype, expression of cell surface hydrophobicity, and binding of extracellular matrix and plasma proteins. PMID:7535283

  16. Multi-Step Fibrinogen Binding to the Integrin αIIbβ3 Detected Using Force Spectroscopy

    PubMed Central

    Litvinov, Rustem I.; Bennett, Joel S.; Weisel, John W.; Shuman, Henry

    2005-01-01

    The regulated ability of integrin αIIbβ3 to bind fibrinogen plays a crucial role in platelet aggregation and hemostasis. We have developed a model system based on laser tweezers, enabling us to measure specific rupture forces needed to separate single receptor-ligand complexes. First of all, we performed a thorough and statistically representative analysis of nonspecific protein-protein binding versus specific αIIbβ3-fibrinogen interactions in combination with experimental evidence for single-molecule measurements. The rupture force distribution of purified αIIbβ3 and fibrinogen, covalently attached to underlying surfaces, ranged from ∼20 to 150 pN. This distribution could be fit with a sum of an exponential curve for weak to moderate (20–60 pN) forces, and a Gaussian curve for strong (>60 pN) rupture forces that peaked at 80–90 pN. The interactions corresponding to these rupture force regimes differed in their susceptibility to αIIbβ3 antagonists or Mn2+, an αIIbβ3 activator. Varying the surface density of fibrinogen changed the total binding probability linearly >3.5-fold but did not affect the shape of the rupture force distribution, indicating that the measurements represent single-molecule binding. The yield strength of αIIbβ3-fibrinogen interactions was independent of the loading rate (160–16,000 pN/s), whereas their binding probability markedly correlated with the duration of contact. The aggregate of data provides evidence for complex multi-step binding/unbinding pathways of αIIbβ3 and fibrinogen revealed at the single-molecule level. PMID:16040750

  17. Effects of fibrinogen concentrate after shock/resuscitation – A comparison between in vivo microvascular clot formation and thromboelastometry

    PubMed Central

    Martini, Judith; Cabrales, Pedro; Fries, Dietmar; Intaglietta, Marcos; Tsai, Amy G.

    2014-01-01

    Objective Dilutional coagulopathy after resuscitation with crystalloids/colloids clinically often appears as diffuse microvascular bleeding. Administration of fibrinogen reduces bleeding and increases maximum clot firmness (MCF), measured by thromboelastometry. Study objective was to implement a model where microvascular bleeding can be directly assessed by visualizing clot formation in microvessels, and correlations can be made to thromboelastometry. Design Randomized animal study. Setting University research laboratory. Subjects Male Syrian Golden hamsters. Interventions Microvessels of Syrian Golden hamsters fitted with a dorsal window chamber were studied using videomicroscopy. After 50% hemorrhage followed by 1 hr of hypovolemia resuscitation with 35% of blood volume using a high molecular weight (MW) HES solution (Hextend®, Hospira, MW 670 kD) occurred. Animals were then treated with 250 mg/kg fibrinogen iv (Laboratoire français du Fractionnement et des Biotechnologies (LFB), Paris, France) or an equal volume of saline before venular vessel wall injuries were made by directed laser irradiation and the ability of microthrombus formation was assessed. Measurements and main results Thromboelastometric measurements of MCF were performed at the beginning and at the end of the experiment. Resuscitation with HES and sham treatment significantly decreased FIBTEM MCF from 32 ± 9 at baseline vs. 13 ± 5 mm after sham treatment (p < 0.001). Infusion of fibrinogen concentrate significantly increased MCF, restoring baseline levels (baseline 32 ± 9 mm; after fibrinogen administration 29 ± 2 mm). In vivo microthrombus formation in laser injured vessels significantly increased in fibrinogen treated animals compared with sham (77% vs. 18%). Conclusions Fibrinogen treatment leads to increased clot firmness in dilutional coagulopathy as measured with thromboelastometry. At the microvascular level this increased clot strength, corresponds to an increased incidence of

  18. Fibrinogen and inflammatory cytokines in spontaneous sputum of sulfur-mustard-exposed civilians--Sardasht-Iran Cohort Study.

    PubMed

    Yaraee, Roya; Hassan, Zuhair Mohammad; Pourfarzam, Shahryar; Rezaei, Abbas; Faghihzadeh, Soghrat; Ebtekar, Massoumeh; Soroush, Mohammad-Reza; Ardestani, Sussan K; Kazemi, Hadi; Mahmoudi, Mahmoud; Ghazanfari, Zeinab; Foroutan, Abbas; Jalaie, Shohreh; Ghazanfari, Tooba

    2013-11-01

    Sulfur mustard (SM) causes late complications in respiratory system of exposed individuals. In this preliminary study, the levels of IL-1α and β, TNF, IL-1Ra, IL-6 and fibrinogen in the spontaneous sputum of SM-exposed individuals were examined 20 years after exposure and the correlation with pulmonary function was tested. The participants were categorized into two major subgroups (hospitalized and non-hospitalized) based on the severity of the clinical complications immediately after exposure. Every participant was visited by a physician; the respiratory functions were checked using spirometry and were categorized as normal, mild, moderate or severe pulmonary complications. The levels of cytokines in the sputum and serum samples were measured using ELISA method. The mean values of TNF, IL-1α and IL-1β were 524.15, 115.15, 1951.33 pg/ml respectively, and the mean levels of IL-1Ra and IL-6 were 6410.52 and 124.44 pg/ml respectively; fibrinogen was 71.59 ng/ml and index of IL-Ra/IL-1β was 7.78. There was more TNF-α and IL-1β and less IL-1Ra and fibrinogen in the sputum of the hospitalized subgroup. The level of TNF-α and IL-1β also increased in moderate and severe pulmonary status comparing with the group with mild disorders, while fibrinogen was lower or decreased significantly in problematic patients. IL-1β and TNF showed positive correlation (r=0.5, and r=0.59, respectively); fibrinogen and IL1Ra/IL-1β have negative correlation with lung function according to the GOLD classification (r=-0.4, and r=-0.61, respectively). It is concluded that sputum cytokines and fibrinogen, reflect the degree of the severity of airway inflammation and the cytokine levels in the sputum might be completely different from the serum fluctuations. PMID:23375935

  19. Combination of recombinant factor VIIa and fibrinogen corrects clot formation in primary immune thrombocytopenia at very low platelet counts.

    PubMed

    Larsen, Ole H; Stentoft, Jesper; Radia, Deepti; Ingerslev, Jørgen; Sørensen, Benny

    2013-01-01

    Haemostatic treatment modalities alternative to platelet transfusion are desirable to control serious acute bleeds in primary immune thrombocytopenia (ITP). This study challenged the hypothesis that recombinant activated factor VII (rFVIIa) combined with fibrinogen concentrate may correct whole blood (WB) clot formation in ITP. Blood from ITP patients (n = 12) was drawn into tubes containing 3·2% citrate and corn trypsin inhibitor 18·3 μg/ml. WB [mean platelet count 22 × 10(9) /l (range 0-42)] was spiked in vitro with buffer, donor platelets (+40 × 10(9) /l), rFVIIa (1 or 4 μg/ml), fibrinogen (1 or 3 mg/ml), or combinations of rFVIIa and fibrinogen. Coagulation profiles were recorded by tissue factor (0·03 pmol/l) activated thromboelastometry. Coagulation in ITP was characterized by a prolonged clotting time (CT, 1490 s (mean)) and a low maximum velocity (MaxVel, 3·4 mm × 100/s) and maximum clot firmness (MCF, 38·2 mm). Fibrinogen showed no haemostatic effect, whereas rFVIIa reduced the CT and increased the MaxVel. The combination of fibrinogen and rFVIIa revealed a significant synergistic effect, improving all parameters (CT 794 s, MaxVel 7·9 mm × 100/s, MCF 50·7 mm) even at very low platelet counts. These data suggest that rFVIIa combined with fibrinogen corrects the coagulopathy of ITP even at very low platelet counts, and may represent an alternative to platelet transfusion. PMID:23151086

  20. Distinct Adsorption Configurations and Self-Assembly Characteristics of Fibrinogen on Chemically Uniform and Alternating Surfaces including Block Copolymer Nanodomains

    PubMed Central

    2015-01-01

    Understanding protein–surface interactions is crucial to solid-state biomedical applications whose functionality is directly correlated with the precise control of the adsorption configuration, surface packing, loading density, and bioactivity of protein molecules. Because of the small dimensions and highly amphiphilic nature of proteins, investigation of protein adsorption performed on nanoscale topology can shed light on subprotein-level interaction preferences. In this study, we examine the adsorption and assembly behavior of a highly elongated protein, fibrinogen, on both chemically uniform (as-is and buffered HF-treated SiO2/Si, and homopolymers of polystyrene and poly(methyl methacrylate)) and varying (polystyrene-block-poly(methyl methacrylate)) surfaces. By focusing on high-resolution imaging of individual protein molecules whose configurations are influenced by protein–surface rather than protein–protein interactions, fibrinogen conformations characteristic to each surface are identified and statistically analyzed for structural similarities/differences in key protein domains. By exploiting block copolymer nanodomains whose repeat distance is commensurate with the length of the individual protein, we determine that fibrinogen exhibits a more neutral tendency for interaction with both polystyrene and poly(methyl methacrylate) blocks relative to the case of common globular proteins. Factors affecting fibrinogen–polymer interactions are discussed in terms of hydrophobic and electrostatic interactions. In addition, assembly and packing attributes of fibrinogen are determined at different loading conditions. Primary orientations of fibrinogen and its rearrangements with respect to the underlying diblock nanodomains associated with different surface coverage are explained by pertinent protein interaction mechanisms. On the basis of two-dimensional stacking behavior, a protein assembly model is proposed for the formation of an extended fibrinogen network

  1. TGFβ2 differentially modulates smooth muscle cell proliferation and migration in electrospun gelatin-fibrinogen constructs.

    PubMed

    Ardila, Diana C; Tamimi, Ehab; Danford, Forest L; Haskett, Darren G; Kellar, Robert S; Doetschman, Tom; Vande Geest, Jonathan P

    2015-01-01

    A main goal of tissue engineering is the development of scaffolds that replace, restore and improve injured tissue. These scaffolds have to mimic natural tissue, constituted by an extracellular matrix (ECM) support, cells attached to the ECM, and signaling molecules such as growth factors that regulate cell function. In this study we created electrospun flat sheet scaffolds using different compositions of gelatin and fibrinogen. Smooth muscle cells (SMCs) were seeded on the scaffolds, and proliferation and infiltration were evaluated. Additionally, different concentrations of Transforming Growth Factor-beta2 (TGFβ2) were added to the medium with the aim of elucidating its effect on cell proliferation, migration and collagen production. Our results demonstrated that a scaffold with a composition of 80% gelatin-20% fibrinogen is suitable for tissue engineering applications since it promotes cell growth and migration. The addition of TGFβ2 at low concentrations (≤ 1 ng/ml) to the culture medium resulted in an increase in SMC proliferation and scaffold infiltration, and in the reduction of collagen production. In contrast, TGFβ2 at concentrations >1 ng/ml inhibited cell proliferation and migration while stimulating collagen production. According to our results TGFβ2 concentration has a differential effect on SMC function and thus can be used as a biochemical modulator that can be beneficial for tissue engineering applications. PMID:25453947

  2. Combined fibrinogen concentration and neutrophil-lymphocyte ratio as a prognostic marker of gastric cancer

    PubMed Central

    ARIGAMI, TAKAAKI; UENOSONO, YOSHIKAZU; MATSUSHITA, DAISUKE; YANAGITA, SHIGEHIRO; UCHIKADO, YASUTO; KITA, YOSHIAKI; MORI, SHINICHIRO; KIJIMA, YUKO; OKUMURA, HIROSHI; MAEMURA, KOSEI; ISHIGAMI, SUMIYA; NATSUGOE, SHOJI

    2016-01-01

    Certain patients with early gastric cancer succumb to recurrent disease and cancer-associated complications. The key cause of recurrence is challenging to determine, since clinical blood markers that are able to predict the tumor properties of gastric cancer are limited. The present study investigated the fibrinogen concentration and neutrophil-lymphocyte ratio (NLR) in blood specimens from patients with gastric cancer, and assessed the clinical applicability of combining the fibrinogen concentration with the NLR (CFS-NLR) as a prognostic marker of gastric cancer. The present study consisted of 275 patients with gastric cancer, who were divided into three groups: Those possessing hyperfibrinogenemia (≥305 mg/dl) and a high NLR (≥2.34; CFS-NLR 2 group); those possessing either hyperfibrinogenemia or a high NLR (CFS-NLR 1 group); or those that possessed neither abnormality (CFS-NLR 0 group). The CFS-NLR was significantly associated with the depth of tumor invasion, lymph node metastasis, lymphovascular invasion and tumor stage (P<0.0001). The prognostic differences among the three groups were significant (P=0.0016). Therefore, the CFS-NLR may be a potentially useful blood marker for predicting tumor progression and the prognosis of patients with gastric cancer. PMID:26893776

  3. Modulation of Dental Pulp Stem Cell Odontogenesis in a Tunable PEG-Fibrinogen Hydrogel System

    PubMed Central

    Lu, Qiqi; Pandya, Mirali; Rufaihah, Abdul Jalil; Rosa, Vinicius; Tong, Huei Jinn; Seliktar, Dror; Toh, Wei Seong

    2015-01-01

    Injectable hydrogels have the great potential for clinical translation of dental pulp regeneration. A recently developed PEG-fibrinogen (PF) hydrogel, which comprises a bioactive fibrinogen backbone conjugated to polyethylene glycol (PEG) side chains, can be cross-linked after injection by photopolymerization. The objective of this study was to investigate the use of this hydrogel, which allows tuning of its mechanical properties, as a scaffold for dental pulp tissue engineering. The cross-linking degree of PF hydrogels could be controlled by varying the amounts of PEG-diacrylate (PEG-DA) cross-linker. PF hydrogels are generally cytocompatible with the encapsulated dental pulp stem cells (DPSCs), yielding >85% cell viability in all hydrogels. It was found that the cell morphology of encapsulated DPSCs, odontogenic gene expression, and mineralization were strongly modulated by the hydrogel cross-linking degree and matrix stiffness. Notably, DPSCs cultured within the highest cross-linked hydrogel remained mostly rounded in aggregates and demonstrated the greatest enhancement in odontogenic gene expression. Consistently, the highest degree of mineralization was observed in the highest cross-linked hydrogel. Collectively, our results indicate that PF hydrogels can be used as a scaffold for DPSCs and offers the possibility of influencing DPSCs in ways that may be beneficial for applications in regenerative endodontics. PMID:26124841

  4. Coagulase and Efb of Staphylococcus aureus Have a Common Fibrinogen Binding Motif

    PubMed Central

    Ko, Ya-Ping; Kang, Mingsong; Ganesh, Vannakambadi K.; Ravirajan, Dharmanand; Li, Bin

    2016-01-01

    ABSTRACT Coagulase (Coa) and Efb, secreted Staphylococcus aureus proteins, are important virulence factors in staphylococcal infections. Coa interacts with fibrinogen (Fg) and induces the formation of fibrin(ogen) clots through activation of prothrombin. Efb attracts Fg to the bacterial surface and forms a shield to protect the bacteria from phagocytic clearance. This communication describes the use of an array of synthetic peptides to identify variants of a linear Fg binding motif present in Coa and Efb which are responsible for the Fg binding activities of these proteins. This motif represents the first Fg binding motif identified for any microbial protein. We initially located the Fg binding sites to Coa’s C-terminal disordered segment containing tandem repeats by using recombinant fragments of Coa in enzyme-linked immunosorbent assay-type binding experiments. Sequence analyses revealed that this Coa region contained shorter segments with sequences similar to the Fg binding segments in Efb. An alanine scanning approach allowed us to identify the residues in Coa and Efb that are critical for Fg binding and to define the Fg binding motifs in the two proteins. In these motifs, the residues required for Fg binding are largely conserved, and they therefore constitute variants of a common Fg binding motif which binds to Fg with high affinity. Defining a specific motif also allowed us to identify a functional Fg binding register for the Coa repeats that is different from the repeat unit previously proposed. PMID:26733070

  5. Novel locus for fibrinogen in 3' region of LEPR gene in island population of Vis (Croatia).

    PubMed

    Tomas, Željka; Petranović, Matea Zajc; Škarić-Jurić, Tatjana; Barešić, Ana; Salihović, Marijana Peričić; Narančić, Nina Smolej

    2014-11-01

    Leptin, a possible mediator between energy homeostasis, inflammation and cardiovascular disease (CVD), acts via leptin receptors. We investigated association of single-nucleotide polymorphisms (SNPs) and haplotypes of the leptin receptor gene (LEPR) with several CVD risk factors: body mass index, waist circumference (WC), serum lipids, fibrinogen and C-reactive protein levels. Thirty-one SNPs in and near LEPR gene were analyzed in 986 inhabitants of the island of Vis, Croatia and 29 SNPs in the inland sample (N=499). We assessed linkage disequilibrium (LD), SNP and haplotype associations with the selected phenotypes. rs4291477 significantly associated with fibrinogen (P=0.003) and rs7539471 marginally significantly with high-density lipoprotein (P=0.004), but only in the Vis sample, while rs10493384 marginally significantly associated with triglyceride levels (P=0.006) in the inland sample. SNPs were grouped into eight LD blocks in Vis and in seven blocks in the inland population. Haplotype A-C-A-A-G-A in block 5 in Vis (rs1782754, rs1171269, rs1022981, rs6673324, rs3790426, rs10493380) and haplotype A-A-A-A in block 4 in the inland data (rs1782754, rs1022981, rs6673324, rs1137100) were nominally associated with WC, P=7.085 × 10(-22) (adjusted P=0.0979) and P=5.496 × 10(-144) (adjusted P=0.1062), respectively. PMID:25296580

  6. Tracheal anastomosis using indocyanine green dye enhanced fibrinogen with a near-infrared diode laser

    NASA Astrophysics Data System (ADS)

    Auteri, Joseph S.; Jeevanandam, Valluvan; Oz, Mehmet C.; Libutti, Steven K.; Kirby, Thomas J.; Smith, Craig R.; Treat, Michael R.

    1990-06-01

    A major obstacle to lung transplantation and combined heart- lung transplantation is dehiscence of the tracheobronchial anastomosis. We explored the possibility of laser welded anastomoses in canine tracheas in vivo. Laser anastomoses were performed on three-quarter circumferential anterior tracheotomies. A continous wave diode laser (808 +1 nm) at a power density of 9.6 watts/cm was used. Human fibrinogen was mixed with indocyanine green dye (ICG, max absorbance 805 nm) and applied to the anastomosis site prior to laser exposure. Animals were sacrificed at 0, 21 and 28 days post-operatively. At sacrifice weld bursting pressures were measured by raising intratracheal pressure using forced ventilation via an endotracheal tube. Sutured and laser welded anastomoses had similar bursting pressures, and exhibited satisfactory histologic evidence of healing. However, compared to polypropylene sutured controls, the laser welded anastomoses exhibited less peritracheal inflammatory reaction and showed visibly smoother luminal surfaces at 21 and 28 days post- operatively. Tracheal anastomosis using ICG dye enhanced fibrinogen combined with the near-infrared diode laser is a promising extension of the technology of laser tissue fusion and deserves further study.

  7. [A preemptive combined liver-kidney transplantation in Aalpha fibrinogen chain renal amyloidosis].

    PubMed

    Delabre, Jean-Philippe; Pageaux, Georges-Philippe; Le Quellec, Alain; Raynaud, Pierre; Grateau, Gilles; Mourad, Georges

    2009-04-01

    The predominant cause of hereditary renal amyloidosis is a mutation of the fibrinogen Aalpha chain (AFib), the most common being the E526V mutation. The evolution towards terminal renal insufficiency is constant and raises the question of renal transplantation and the risk of recurrence. We describe the case of a Portuguese woman with the E526V mutation without any renal or hepatic history in her family which developed a nephrotic syndrome at the age of 35, followed by stage 5 renal insufficiency. Because of the risk of recurrence of amyloidosis on its transplant, we carried out a combined transplantation liver-kidney despite the absence of clinical or biological hepatic abnormalities. Four years later, the result is excellent and there is no sign of the disease on the new organs. This successful experience as well as the five other published cases of combined liver-kidney transplantation in Aalpha fibrinogen chain amyloidosis, demonstrates the feasibility and efficacy of this treatment in AFib amyloidosis. PMID:19013120

  8. Molecular interaction studies of hemostasis: fibrinogen ligand-human platelet receptor interactions.

    PubMed

    Lee, Imshik; Marchant, Roger E

    2003-01-01

    The interactions between fibrinogen ligands and platelet receptor alpha(IIb)beta(3) were studied under physiological conditions by atomic force microscopy (AFM). Two linear peptide sequences in fibrinogen, RGD and HHLGGAKQAGDV, play central roles in the regulation of hemostasis and thrombosis by facilitating adhesion and aggregation of platelets. In order to measure the interactions (i.e., debonding force), oligopeptides, GSSSGaaa, where aaa is -RGDSPA or -HHLGGAKQAGDV, were synthesized and grafted on to the surface of AFM probe tips. The interaction forces between a peptide-modified AFM probe tip and platelet surface were determined from pN to nN levels using AFM force measurements. Our results show that the zero kinetic off-rate, K(off)(0), for RGDSPA is significantly smaller than that for HHLGGAKQAGDV, under the consideration of flexible receptor surfaces. From our analysis, the K(off)(0), the single molecular binding energy E(b), and the transition state x(b), were extracted from the data, and estimated to be 1.53s(-1), -2.64x10(-20)J and 1.03A for the RGD-alpha(IIb)beta(3) system, and 47.58s(-1), 2.67x10(-20), 1.09A for the HHLGGAKQAGDV-alpha(IIb)beta(3) system, respectively. PMID:12801687

  9. A detailed consideration of a principal domain of vertebrate fibrinogen and its relatives.

    PubMed Central

    Doolittle, R. F.

    1992-01-01

    Vertebrate fibrinogen is a complex multidomained protein, the structure of which has been inferred mainly from electron microscopy and amino acid sequence studies. Among its most prominent features are two terminal globules, moieties that are mostly composed of the carboxyl-terminal two-thirds of the beta and gamma chains. Sequences homologous to the latter segments are found in several other animal proteins, always as the carboxyl-terminal contributions. An alignment of 15 amino acid sequences from various fibrinogens and related proteins has been used to make judgments about secondary structure. The nature of amino acids at each position in the alignment was used to distinguish alpha helices and beta structure on the one hand from loops and turns on the other, and the resulting assignments compared with predictions of secondary structure by other methods. Additionally, constraints imposed by the locations of cystines, carbohydrate attachment residues, and proteinase-sensitive points provided further insights into the general organization of the postulated secondary structures. Other ancillary data, including the effects of bound calcium and the locations of labeled or variant residues, were also considered. An intriguing similarity to a portion of the recently reported structure of a calcium-dependent lectin is noted. PMID:1304888

  10. Optical tweezers study of red blood cell aggregation and disaggregation in plasma and protein solutions

    NASA Astrophysics Data System (ADS)

    Lee, Kisung; Kinnunen, Matti; Khokhlova, Maria D.; Lyubin, Evgeny V.; Priezzhev, Alexander V.; Meglinski, Igor; Fedyanin, Andrey A.

    2016-03-01

    Kinetics of optical tweezers (OT)-induced spontaneous aggregation and disaggregation of red blood cells (RBCs) were studied at the level of cell doublets to assess RBC interaction mechanics. Measurements were performed under in vitro conditions in plasma and fibrinogen and fibrinogen + albumin solutions. The RBC spontaneous aggregation kinetics was found to exhibit different behavior depending on the cell environment. In contrast, the RBC disaggregation kinetics was similar in all solutions qualitatively and quantitatively, demonstrating a significant contribution of the studied proteins to the process. The impact of the study on assessing RBC interaction mechanics and the protein contribution to the reversible RBC aggregation process is discussed.

  11. Aestivation induces changes in transcription and translation of coagulation factor II and fibrinogen gamma chain in the liver of the African lungfish Protopterus annectens.

    PubMed

    Hiong, Kum C; Tan, Xiang R; Boo, Mel V; Wong, Wai P; Chew, Shit F; Ip, Yuen K

    2015-12-01

    This study aimed to sequence and characterize two pro-coagulant genes, coagulation factor II (f2) and fibrinogen gamma chain (fgg), from the liver of the African lungfish Protopterus annectens, and to determine their hepatic mRNA expression levels during three phases of aestivation. The protein abundance of F2 and Fgg in the liver and plasma was determined by immunoblotting. The results indicated that F2 and Fgg of P. annectens were phylogenetically closer to those of amphibians than those of teleosts. Three days of aestivation resulted in an up-regulation in the hepatic fgg mRNA expression level, while 6 days of aestivation led to a significant increase (3-fold) in the protein abundance of Fgg in the plasma. Hence, there could be an increase in the blood-clotting ability in P. annectens during the induction phase of aestivation. By contrast, the blood-clotting ability in P. annectens might be reduced in response to decreased blood flow and increased possibility of thrombosis during the maintenance phase of aestivation, as 6 months of aestivation led to significant decreases in mRNA expression levels of f2 and fgg in the liver. There could also be a decrease in the export of F2 and Fgg from the liver to the plasma so as to avert thrombosis. Three to 6 days after arousal from 6 months of aestivation, the protein abundance of F2 and Fgg recovered partially in the plasma of P. annectens; a complete recovery of the transcription and translation of f2/F2 in the liver might occur only after refeeding. PMID:26449974

  12. Fibrinogen Test

    MedlinePlus

    ... Related tests: PT and INR , PTT , D-dimer , Coagulation Factors , Thrombin Time , hs-CRP At a Glance ... and D-dimer to help diagnose disseminated intravascular coagulation (DIC) or abnormal fibrinolysis Occasionally to help monitor ...

  13. Plasma viscosity elevations with simulated weightlessness

    NASA Technical Reports Server (NTRS)

    Martin, D. G.; Convertino, V. A.; Goldwater, D.; Ferguson, E. W.; Schoomaker, E. B.

    1986-01-01

    A hypothesis correlating an increase in blood viscosity during bed rest to a decrease in aerobic capacity during simulated weightlessness is tested. Eight human subjects were studied on the sixth day of bed rest during two consecutive 10-d bed rest periods separated by a 14-d recovery interval designed to simulate the flight-layover schedule of Shuttle astronauts. Plasma viscosity and volume were measured, together with maximal aerobic capacity (VO2max). An increase in hematocrit, plasma protein, and fibrinogen concentrations was found, contributing to an elevation in plasma viscosity. VO2max decreased significantly in the first, but not the second bed rest cycle, and though many individuals exhibited a decrease in plasma volume and aerobic capacity coupled with elevated plasma viscosity, correlations between these variables were lacking. It is concluded that the decrease in VO2max observed following simulated weightlessness cannot be attributed to alterations in muscle blood flow resulting from increased blood viscosity.

  14. [Dysfibrinogenemia developed in a pregnant woman who has fibrinogen AαThr312Ala (ACT/GCT) polymorphism].

    PubMed

    Yamaguchi, Ayaka; Taga, Atsuko; Kamei, Saori; Wada, Michiko; Fujita, Yohta; Wada, Hideo; Fujita, Kohei

    2016-01-01

    Blood coagulation factors play an essential role in pregnancy. We describe a 30-year-old pregnant woman whose course was complicated by dysfibrinogenemia with polymorphism of fibrinogen AαThr312Ala (rs6050) GG genotype. She was admitted to our hospital for genital bleeding and a huge subchorionic hematoma at 6 gestational weeks. Her first pregnancy and delivery had been uneventful, whereas her second and third pregnancies had resulted in spontaneous abortions with massive subchorionic hematomas. Her fibrinogen activity level was 125 mg/dl and this was lower than her fibrinogen antigen level. We administered tranexamic acid early in the pregnancy, and the subchorionic hematoma diminished in size in accordance with the increase of her fibrinogen level. At 16 gestational weeks, her D-dimer levels were elevated, and heparin treatment was initiated as an alternative. A male infant was delivered at 36 gestational weeks. Intrapartum hemorrhage was 600 g. Patients with coagulation abnormalities are often asymptomatic in the absence of pregnancy. However, when they become pregnant, the spontaneous abortion rate is high. Careful observation and effective management of coagulation abnormalities are essential for such patients to carry their pregnancies to term. PMID:26861101

  15. Macrophage-derived IL-18 and increased fibrinogen deposition are age-related inflammatory signatures of vascular remodeling.

    PubMed

    Rodriguez-Menocal, Luis; Faridi, Mohd Hafeez; Martinez, Laisel; Shehadeh, Lina A; Duque, Juan C; Wei, Yuntao; Mesa, Annia; Pena, Angela; Gupta, Vineet; Pham, Si M; Vazquez-Padron, Roberto I

    2014-03-01

    Aging has been associated with pathological vascular remodeling and increased neointimal hyperplasia. The understanding of how aging exacerbates this process is fundamental to prevent cardiovascular complications in the elderly. This study proposes a mechanism by which aging sustains leukocyte adhesion, vascular inflammation, and increased neointimal thickness after injury. The effect of aging on vascular remodeling was assessed in the rat balloon injury model using microarray analysis, immunohistochemistry, and LINCOplex assays. The injured arteries in aging rats developed thicker neointimas than those in younger animals, and this significantly correlated with a higher number of tissue macrophages and increased vascular IL-18. Indeed, IL-18 was 23-fold more abundant in the injured vasculature of aged animals compared with young rats, while circulating levels were similar in both groups of animals. The depletion of macrophages in aged rats with clodronate liposomes ameliorated vascular accumulation of IL-18 and significantly decreased neointimal formation. IL-18 was found to inhibit apoptosis of vascular smooth muscle cells (VSMC) and macrophages, thus favoring both the formation and inflammation of the neointima. In addition, injured arteries of aged rats accumulated 18-fold more fibrinogen-γ than those of young animals. Incubation of rat peritoneal macrophages with immobilized IL-18 increased leukocyte adhesion to fibrinogen and suggested a proinflammatory positive feedback loop among macrophages, VSMC, and the deposition of fibrinogen during neointimal hyperplasia. In conclusion, our data reveal that concentration changes in vascular cytokine and fibrinogen following injury in aging rats contribute to local inflammation and postinjury neointima formation. PMID:24414074

  16. Macrophage-derived IL-18 and increased fibrinogen deposition are age-related inflammatory signatures of vascular remodeling

    PubMed Central

    Rodriguez-Menocal, Luis; Faridi, Mohd Hafeez; Martinez, Laisel; Shehadeh, Lina A.; Duque, Juan C.; Wei, Yuntao; Mesa, Annia; Pena, Angela; Gupta, Vineet; Pham, Si M.

    2014-01-01

    Aging has been associated with pathological vascular remodeling and increased neointimal hyperplasia. The understanding of how aging exacerbates this process is fundamental to prevent cardiovascular complications in the elderly. This study proposes a mechanism by which aging sustains leukocyte adhesion, vascular inflammation, and increased neointimal thickness after injury. The effect of aging on vascular remodeling was assessed in the rat balloon injury model using microarray analysis, immunohistochemistry, and LINCOplex assays. The injured arteries in aging rats developed thicker neointimas than those in younger animals, and this significantly correlated with a higher number of tissue macrophages and increased vascular IL-18. Indeed, IL-18 was 23-fold more abundant in the injured vasculature of aged animals compared with young rats, while circulating levels were similar in both groups of animals. The depletion of macrophages in aged rats with clodronate liposomes ameliorated vascular accumulation of IL-18 and significantly decreased neointimal formation. IL-18 was found to inhibit apoptosis of vascular smooth muscle cells (VSMC) and macrophages, thus favoring both the formation and inflammation of the neointima. In addition, injured arteries of aged rats accumulated 18-fold more fibrinogen-γ than those of young animals. Incubation of rat peritoneal macrophages with immobilized IL-18 increased leukocyte adhesion to fibrinogen and suggested a proinflammatory positive feedback loop among macrophages, VSMC, and the deposition of fibrinogen during neointimal hyperplasia. In conclusion, our data reveal that concentration changes in vascular cytokine and fibrinogen following injury in aging rats contribute to local inflammation and postinjury neointima formation. PMID:24414074

  17. Insulin counter-regulatory factors, fibrinogen and C-reactive protein during olanzapine administration: effects of the antidiabetic metformin.

    PubMed

    Baptista, Trino; Sandia, Ignacio; Lacruz, Anny; Rangel, Nairy; de Mendoza, Soaira; Beaulieu, Serge; Contreras, Quilianio; Galeazzi, Tatiana; Vargas, Doritza

    2007-03-01

    In this study, the Authors assessed some insulin counter-regulatory factors, fibrinogen and C-reactive protein after olanzapine administration, and the effect of metformin on these variables, 37 patients with chronic schizophrenia were given olanzapine (10 mg/day for 14 weeks). Nineteen patients received metformin (850-2550 mg/day) and 18 received placebo in a randomized, double-blind protocol. The following variables were quantified before and after olanzapine: cortisol, leptin, tumor necrosis factor-alpha, glucagon, growth hormone, fibrinogen and C-reactive protein. Results were correlated with the changes in body weight and the insulin resistance index. We have reported elsewhere that metformin did not prevent olanzapine-induced weight gain, and the insulin resistance index significantly decreased after metformin and placebo; Baptista T, et al. Can J Psychiatry 2006; 51: 192-196. Cortisol, tumor necrosis factor-alpha and fibrinogen levels significantly decreased in both groups. Glucagon significantly increased after metformin (P=0.03). Leptin tended to increase after placebo (P=0.1) and displayed a small nonsignificant reduction after metformin. The C-reactive protein did not change significantly in any group. Contrarily to most published studies, olanzapine was associated with decreased insulin resistance. Decrements in cortisol, fibrinogen and tumor necrosis factor-alpha levels point to an improvement in the metabolic profile. The trend for leptin to increase after placebo, but not after metformin in spite of similar weight gain suggests a beneficial effect of this antidiabetic agent. PMID:17293706

  18. Influence of spacer length on heparin coupling efficiency and fibrinogen adsorption of modified titanium surfaces

    PubMed Central

    Tebbe, David; Thull, Roger; Gbureck, Uwe

    2007-01-01

    Background Chemical bonding of the drug onto surfaces by means of spacer molecules is accompanied with a reduction of the biological activity of the drug due to a constricted mobility since normally only short spacer molecule like aminopropyltrimethoxysilane (APMS) are used for drug coupling. This work aimed to study covalent attachment of heparin to titanium(oxide) surfaces by varying the length of the silane coupling agent, which should affect the biological potency of the drug due to a higher mobility with longer spacer chains. Methods Covalent attachment of heparin to titanium metal and TiO2 powder was carried out using the coupling agents 3-(Trimethoxysilyl)-propylamine (APMS), N- [3-(Trimethoxysilyl)propyl]ethylenediamine (Diamino-APMS) and N1- [3-(Trimethoxy-silyl)-propyl]diethylenetriamine (Triamino-APMS). The amount of bound coupling agent and heparin was quantified photometrically by the ninhydrin reaction and the tolidine-blue test. The biological potency of heparin was determined photometrically by the chromogenic substrate Chromozym TH and fibrinogen adsorption to the modified surfaces was researched using the QCM-D (Quartz Crystal Microbalance with Dissipation Monitoring) technique. Results Zeta-potential measurements confirmed the successful coupling reaction; the potential of the unmodified anatase surface (approx. -26 mV) shifted into the positive range (> + 40 mV) after silanisation. Binding of heparin results in a strongly negatively charged surface with zeta-potentials of approx. -39 mV. The retaining biological activity of heparin was highest for the spacer molecule Triamino-APMS. QCM-D measurements showed a lower viscosity for adsorbed fibrinogen films on heparinised surfaces by means of Triamino-APMS. Conclusion The remaining activity of heparin was found to be highest for the covalent attachment with Triamino-APMS as coupling agent due to the long chain of this spacer molecule and therefore the highest mobility of the drug. Furthermore, the

  19. Non-Covalent Interaction of α2-Antiplasmin with Fibrin(ogen): Localization of α2-Antiplasmin Binding Sites

    PubMed Central

    Tsurupa, Galina; Yakovlev, Sergiy; McKee, Patrick; Medved, Leonid

    2010-01-01

    Covalent incorporation (cross-linking) of plasmin inhibitor α2-antiplasmin (α2-AP) into fibrin clots increases their resistance to fibrinolysis. We hypothesized that α2-AP may also interact non-covalently with fibrin prior to its covalent cross-linking. To test this hypothesis, we studied binding of α2-AP to fibrin(ogen) and its fragments by ELISA and Surface Plasmon Resonance. The experiments revealed that α2-AP binds to polymeric fibrin and surface-adsorbed fibrin(ogen) while no binding was observed with fibrinogen in solution. To localize the α2-AP-binding sites, we studied the interaction of α2-AP with the fibrin(ogen)-derived D1, D-D and E3 fragments, and the recombinant αC region and its constituents, αC-connector and αC-domain and its sub-domains, which together encompass practically the whole fibrin(ogen) molecule. In ELISA, α2-AP bound to immobilized D1, D-D, αC region, αC-domain and its C-terminal sub-domain. The binding was Lys-independent and was not inhibited by plasminogen or tPA. Furthermore, the affinity of α2-AP to D-D was significantly increased in the presence of plasminogen while that to the αC-domain remained unaffected. Altogether, these results indicate that the fibrin(ogen) D region and the C-terminal sub-domain of the αC-domain contain high affinity α2-AP-binding sites that are cryptic in fibrinogen and exposed in fibrin or adsorbed fibrinogen, and the presence of plasminogen facilitates interaction of α2-AP with the D regions. The discovered non-covalent interaction of α2-AP with fibrin may contribute to regulation of the initial stage of fibrinolysis and provide proper orientation of the cross-linking sites to facilitate covalent cross-linking of α2-AP to the fibrin clot. PMID:20687529

  20. Characterization of the gene encoding a fibrinogen-related protein expressed in Crassostrea gigas hemocytes.

    PubMed

    Skazina, M A; Gorbushin, A M

    2016-07-01

    Four exons of the CgFrep1 gene (3333 bp long) encode a putative fibrinogen-related protein (324 aa) bearing a single C-terminal FBG domain. Transcripts of the gene obtained from hemocytes of different Pacific oysters show prominent individual variation based on SNP and indels of tandem repeats resulted in polymorphism of N-terminus of the putative CgFrep1 polypeptide. The polypeptide chain bears N-terminal coiled-coil region potentially acting as inter-subunit interface in the protein oligomerization. It is suggested that CgFrep1 gene encodes the oligomeric lectin composed of at least two subunits. PMID:27189918

  1. Identification of carboxyl terminal peptide of Fibrinogen as a potential serum biomarker for gastric cancer.

    PubMed

    Wu, Cheng; Luo, Zhiwen; Tang, Dan; Liu, Lijie; Yao, Dingkang; Zhu, Liang; Wang, Zhiqiang

    2016-05-01

    Gastric cancer (GC) is a very common disease worldwide where new serum biomarkers are urgently needed to improve their early diagnosis. In this study, we aim to search for the potential serum protein/peptide biomarkers of GC by using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). We first obtained the serum protein/peptide profiles from a training dataset including 30 patients with GC, 16 cases with chronic benign gastric disease (CGD), and 30 normal controls (CON) where 15 protein peaks were identified to exhibit the obvious deviation (P < 0.001, Wilcoxon rank sum test) among GC, CGD, and CON analyzed by Biomarker Wizard 3.1 software with three protein peaks with mass-to-charge (m/z) ratio 5910, 5342, and 6439 further confirmed in the validation dataset. Among the three protein peaks, peak 5910 displayed the most significantly different which could distinguish GC patients from CGD and CON with a sensitivity of 86.3 %, a specificity of 91.3 %, and the area under the receiver operating characteristic curve (AUC) of 0.89 by using the optimal cutoff value of 17.3. We further identified peak 5910 as the carboxyl terminal fraction of Fibrinogen α by LC-MS and validated its identity by antiserum-mediated SELDI-based immunodepletion assays. In sum, SELDI-TOF-MS method could effectively generate serum peptidome in cancer patients and provide a new approach to identify potentially diagnostic and prognostic biomarkers for cancer. The carboxyl terminal fraction of Fibrinogen α may be a potential serological biomarker for GC diagnosis. PMID:26662807

  2. Vascular pentraxin 3 controls arterial thrombosis by targeting collagen and fibrinogen induced platelets aggregation

    PubMed Central

    Bonacina, F.; Barbieri, S.S.; Cutuli, L.; Amadio, P.; Doni, A.; Sironi, M.; Tartari, S.; Mantovani, A.; Bottazzi, B.; Garlanda, C.; Tremoli, E.; Catapano, A.L.; Norata, G.D.

    2016-01-01

    Aim The long pentraxin PTX3 plays a non-redundant role during acute myocardial infarction, atherosclerosis and in the orchestration of tissue repair and remodeling during vascular injury, clotting and fibrin deposition. The aim of this work is to investigate the molecular mechanisms underlying the protective role of PTX3 during arterial thrombosis. Methods and results PTX3 KO mice transplanted with bone marrow from WT or PTX3 KO mice presented a significant reduction in carotid artery blood flow following FeCl3 induced arterial thrombosis (− 80.36 ± 11.5% and − 95.53 ± 4.46%), while in WT mice transplanted with bone marrow from either WT or PTX3 KO mice, the reduction was less dramatic (− 45.55 ± 1.37% and − 53.39 ± 9.8%), thus pointing to a protective effect independent of a hematopoietic cell's derived PTX3. By using P-selectin/PTX3 double KO mice, we further excluded a role for P-selectin, a target of PTX3 released by neutrophils, in vascular protection played by PTX3. In agreement with a minor role for hematopoietic cell-derived PTX3, platelet activation (assessed by flow cytometric expression of markers of platelet activation) was similar in PTX3 KO and WT mice as were haemostatic properties. Histological analysis indicated that PTX3 localizes within the thrombus and the vessel wall, and specific experiments with the N-terminal and the C-terminal PTX3 domain showed the ability of PTX3 to selectively dampen either fibrinogen or collagen induced platelet adhesion and aggregation. Conclusion PTX3 interacts with fibrinogen and collagen and, by dampening their pro-thrombotic effects, plays a protective role during arterial thrombosis. PMID:26976330

  3. Characterization of the 5'-flanking region of the gene for the alpha chain of human fibrinogen.

    PubMed

    Hu, C H; Harris, J E; Davie, E W; Chung, D W

    1995-11-24

    The 5'-flanking region of the gene coding for the alpha chain of human fibrinogen was isolated, sequenced, and characterized. The principal site of transcription initiation was determined by primer extension analysis and the RNase protection assay and shown to be at an adenine residue located 55 nucleotides upstream from the initiator methionine codon, or 13,399 nucleotides down-stream from the polyadenylation site of the gene coding for the gamma chain. Transient expression of constructs containing sequentially deleted 5'-flanking sequences of the alpha chain gene fused to the chloramphenicol acetyltransferase reporter gene showed that the promoter was liver-specific and inducible by interleukin 6 (IL-6). The shortest DNA fragment with significant promoter activity and full response to IL-6 stimulation encompassed the region from -217 to +1 base pairs (bp). Although six potential IL-6 responsive sequences homologous to the type II IL-6 responsive element were present, a single sequence of CTGGGA localized from -122 to -127 bp was shown to be a functional element in IL-6 induction. A hepatocyte nuclear factor 1 (HNF-1) binding site, present from -47 to -59 bp, in combination with other upstream elements, was essential for liver-specific expression of the gene. A functional CCAAT/enhancer binding protein site (C/EBP, -134 to -142 bp) was also identified within 217 bp from the transcription initiation site. An additional positive element (-1393 to -1133 bp) and a negative element (-1133 to -749 bp) were also found in the upstream region of the alpha-fibrinogen gene. PMID:7499335

  4. Studies of activated GPIIb/IIIa receptors on the luminal surface of adherent platelets. Paradoxical loss of luminal receptors when platelets adhere to high density fibrinogen.

    PubMed Central

    Coller, B S; Kutok, J L; Scudder, L E; Galanakis, D K; West, S M; Rudomen, G S; Springer, K T

    1993-01-01

    The accessibility of activated GPIIb/IIIa receptors on the luminal surface of platelets adherent to damaged blood vessels or atherosclerotic plaques is likely to play a crucial role in subsequent platelet recruitment. To define better the factors involved in this process, we developed a functional assay to assess the presence of activated, luminal GPIIb/IIIa receptors, based on their ability to bind erythrocytes containing a high density of covalently coupled RGD-containing peptides (thromboerythrocytes). Platelets readily adhered to wells coated with purified type I rat skin collagen and the adherent platelets bound a dense lawn of thromboerythrocytes. With fibrinogen-coated wells, platelet adhesion increased as the fibrinogen-coating concentration increased, reaching a plateau at about 11 micrograms/ml. Thromboerythrocyte binding to the platelets adherent to fibrinogen showed a paradoxical response, increasing at fibrinogen coating concentrations up to approximately 4-6 micrograms/ml and then dramatically decreasing at higher fibrinogen-coating concentrations. Scanning electron microscopy demonstrated that the morphology of platelets adherent to collagen was similar to that of platelets adherent to low density fibrinogen, with extensive filopodia formation and ruffling. In contrast, platelets adherent to high density fibrinogen showed a bland, flattened appearance. Immunogold staining of GPIIb/IIIa receptors demonstrated concentration of the receptors on the filopodia, and depletion of receptors on the flattened portion of the platelets. Thus, there is a paradoxical loss of accessible, activated GPIIb/IIIa receptors on the luminal surface of platelets adherent to high density fibrinogen. Two factors may contribute to this result: engagement of GPIIb/IIIa receptors with fibrinogen on the abluminal surface leading to the loss of luminal receptors, and loss of luminal filopodia that interact with thromboerythrocytes. These data provide insight into the differences

  5. Polyphenol-rich juices reduce blood pressure measures in a randomised controlled trial in high normal and hypertensive volunteers.

    PubMed

    Tjelle, Torunn Elisabeth; Holtung, Linda; Bøhn, Siv Kjølsrud; Aaby, Kjersti; Thoresen, Magne; Wiik, Siv Åshild; Paur, Ingvild; Karlsen, Anette Solli; Retterstøl, Kjetil; Iversen, Per Ole; Blomhoff, Rune

    2015-10-14

    Intake of fruits and berries may lower blood pressure (BP), most probably due to the high content of polyphenols. In the present study, we tested whether consumption of two polyphenol-rich juices could lower BP. In a randomised, double-blinded, placebo-controlled trial of 12 weeks, 134 healthy individuals, aged 50-70 years, with high normal range BP (130/85-139/89 mmHg, seventy-two subjects) or stage 1-2 hypertension (140/90-179/109 mmHg, sixty-two subjects), were included. They consumed 500 ml/d of one of either (1) a commercially available polyphenol-rich juice based on red grapes, cherries, chokeberries and bilberries; (2) a juice similar to (1) but enriched with polyphenol-rich extracts from blackcurrant press-residue or (3) a placebo juice (polyphenol contents 245·5, 305·2 and 76 mg/100 g, respectively). Resting BP was measured three times, with a 1 min interval, at baseline and after 6 and 12 weeks of intervention. Systolic BP significantly reduced over time (6 and 12 weeks, respectively) in the pooled juice group compared with the placebo group in the first of the three measurements, both for the whole study group (6·9 and 3·4 mmHg; P= 0·01) and even more pronounced in the hypertensive subjects when analysed separately (7·3 and 6·8 mmHg; P= 0·04). The variation in the BP measurements was significantly reduced in the pooled juice group compared with the placebo group (1·4 and 1·7 mmHg; P= 0·03). In conclusion, the present findings suggest that polyphenol-rich berry juice may contribute to a BP- and BP variability lowering effect, being more pronounced in hypertensive than in normotensive subjects. PMID:26227795

  6. Specific Effects of Fibrinogen and the γA and γ′-Chain Fibrinogen Variants on Angiogenesis and Wound Healing

    PubMed Central

    Cheung, Elim Y.L.; Weijers, Ester M.; Tuk, Bastiaan; Scheffer, Reinilde; Leebeek, Frank W.; van Neck, Johan W.; Koolwijk, Pieter

    2015-01-01

    In a newly formed wound, the natural fibrin network provides the first temporary matrix for tissue repair. Topical application of fibrin to a new wound may improve wound healing. A matrix of the common natural γ′ fibrin variant may further improve wound healing because it is expected to have a different architecture and this will influence angiogenesis, because it possesses increased thrombin and factor XIII binding and decreased platelet binding, when compared with the common γA fibrin matrix. Our objective was to determine the effect of fibrinogen and its γA and γ′ variants on angiogenesis and wound healing. We used in vitro angiogenesis models and an in vivo rat full-thickness excisional wound healing model. When comparing γA and γ′ fibrin in vitro, more tube-like structures were formed on day 7 in γA fibrin than in γ′ fibrin (13.83±6.12 AU vs. 6.1±1.46 AU). Wounds treated with fibrin demonstrated improved healing in vivo with more perfusion (47%±3% vs. 26%±4%, p<0.01 in placebo) and higher CD34 density score (2.0±0.4 vs. 2.8±0.1, p<0.01) on day 21 with fibrin matrices when compared with placebo-treated wounds. Increased perfusion was observed in γA fibrin-treated wounds on day 21 (53%±10% vs. 41%±7% for γ′ fibrin). The other parameters showed slightly improved (not significant) wound healing with γA fibrin compared with γ′ fibrin matrices. In conclusion, the use of fibrin and fibrin variant matrices offers an interesting methodology to stimulate the wound healing process. PMID:24974891

  7. [The radioimmunological assay of fibrinogen breakdown products with E antigen during postoperative venous thromboses. Study in 46 cases of arthroplasty for osteoarthrosis of the hip (author's transl)].

    PubMed

    Dechavanne, M; Ville, D; Clermont, N; Pouillaude, J M; Clermont, A; Viala, J J; de Mourgues, G

    1977-11-26

    Twenty six patients (without thrombosis) had a normal 125I-fibrinogen test, among whom 15 had a normal phlebography; 18 patients (with thrombosis) had a positive 125I-fibrinogen test among whom 11 had a positive phlebography. There was a discrepancy between phlebography and 125I-fibrinogen test in 2 patients. In patients with thrombosis, there is a significantly increase of FgE levels for several days after the intervention. However the measurement of FgE is not a reliable test (4% of false positive and 38% of false negative); but it is always elevated in femoral and popliteal thrombosis. PMID:604924

  8. Aggregation of human platelets by endotoxic glycolipid-bearing Salmonella minnesota Re595 is prevented by synthetic peptide analogs of cell adhesion sites of fibrinogen and fibronectin

    SciTech Connect

    Timmons, S.; Grabarek, J.; Kloczewiak, M.; Hawiger, J.

    1986-03-01

    Thrombocytopenia often accompanies sepsis due to endotoxin producing gram-negative bacteria. The authors have observed that mutant Re595 of S. minnesota induced aggregation of human platelets separated from plasma fibrinogen (Theta) and other proteins. This aggregation is dependent on ADP secreted from storage granules in response to mutant Re595. Platelet aggregation induced by mutant Re595 was prevented by simultaneously added EDTA and EGTA (5mM), whereas secretion of /sup 14/C-serotonin was maintained. Preincubation of platelets with chelators (1 hr, 37/sup 0/C), known to dissociate irreversibly the platelet membrane glycoprotein IIb x IIIa complex, abolished aggregation while serotonin secretion was decreased by only one fourth. Since the GPIIb x IIIa complex constitutes the receptor for Theta, its role was examined using synthetic peptide analogs of sites on gamma and alpha chains of Theta. Gamma 400-411 (225 ..mu..M) inhibited platelet aggregation induced by mutant Re595 while serotonin secretion was unaffected. Alpha 572-575 (RGDS; 100 ..mu..M), analogous to cell adhesion site of fibronectin, also prevented aggregation induced by mutant Re595. Thus, mutant Re595 causes platelet aggregation which is divalent cation-dependent and proceeds via receptor pathway for secreted adhesive macromolecules.

  9. Platelets in hemostasis and thrombosis: Novel mechanisms of fibrinogen-independent platelet aggregation and fibronectin-mediated protein wave of hemostasis

    PubMed Central

    Hou, Yan; Carrim, Naadiya; Wang, Yiming; Gallant, Reid C.; Marshall, Alexandra; Ni, Heyu

    2015-01-01

    Abstract Platelets are small anucleate cells generated from megakaryocytes in the bone marrow. Although platelet generation, maturation, and clearance are still not fully understood, significant progress has been made in the last 1-2 decades. In blood circulation, platelets can quickly adhere and aggregate at sites of vascular injury, forming the platelet plug (i.e. the first wave of hemostasis). Activated platelets can also provide negatively charged phosphatidylserine-rich membrane surface that enhances cell-based thrombin generation, which facilitates blood coagulation (i.e. the second wave of hemostasis). Platelets therefore play central roles in hemostasis. However, the same process of hemostasis may also cause thrombosis and vessel occlusion, which are the most common mechanisms leading to heart attack and stroke following ruptured atherosclerotic lesions. In this review, we will introduce the classical mechanisms and newly discovered pathways of platelets in hemostasis and thrombosis, including fibrinogen-independent platelet aggregation and thrombosis, and the plasma fibronectin-mediated “protein wave” of hemostasis that precedes the classical first wave of hemostasis. Furthermore, we briefly discuss the roles of platelets in inflammation and atherosclerosis and the potential strategies to control atherothrombosis. PMID:26541706

  10. Srr2, a multifaceted adhesin expressed by ST-17 hypervirulent Group B Streptococcus involved in binding to both fibrinogen and plasminogen.

    PubMed

    Six, Anne; Bellais, Samuel; Bouaboud, Abdelouhab; Fouet, Agnès; Gabriel, Christelle; Tazi, Asmaa; Dramsi, Shaynoor; Trieu-Cuot, Patrick; Poyart, Claire

    2015-09-01

    The Group B Streptococcus (GBS) 'hypervirulent' ST-17 clone is strongly associated with invasive neonatal meningitis. Comparative genome analyses revealed that the serine-rich repeat (Srr) glycoprotein Srr2 is a cell wall-anchored protein specific for ST-17 strains, the non-ST-17 isolates expressing Srr1. Here, we unravel the binding capacity of GBS Srr proteins to relevant components of the host fibrinolysis pathway. We demonstrate that: (i) Srr2 binds plasminogen and plasmin whereas Srr1 does not; (ii) the ability of ST-17 strains to bind fibrinogen reflects a high level surface display of Srr2 combined with a higher affinity of Srr2 than Srr1 to bind this ligand; and (iii) Srr2 binding to host plasma proteins results in the formation of bacterial aggregates that are efficiently endocytosed by phagocytes. Importantly, we show that Srr2 increased bacterial survival to phagocytic killing and bacterial persistence in a murine model of meningitis. We conclude that Srr2 is a multifaceted adhesin used by the ST-17 clone to hijack ligands of the host coagulation system, thereby contributing to bacterial dissemination and invasiveness, and ultimately to meningitis. PMID:26094503

  11. Association of a high normalized protein catabolic rate and low serum albumin level with carpal tunnel syndrome in hemodialysis patients.

    PubMed

    Huang, Wen-Hung; Hsu, Ching-Wei; Weng, Cheng-Hao; Yen, Tzung-Hai; Lin, Jui-Hsiang; Lee, Meng

    2016-06-01

    Carpal tunnel syndrome (CTS) is the most common mononeuropathy in patients with end-stage renal disease (ESRD). The association between chronic inflammation and CTS in hemodialysis (HD) patients has rarely been investigated. HD patients with a high normalized protein catabolic rate (nPCR) and low serum albumin level likely have adequate nutrition and inflammation. In this study, we assume that a low serum albumin level and high nPCR is associated with CTS in HD patients. We recruited 866 maintenance hemodialysis (MHD) patients and divided them into 4 groups according to their nPCR and serum albumin levels: (1) nPCR <1.2 g/kg/d and serum albumin level <4 g/dL; (2) nPCR ≥1.2 g/kg/d and serum albumin level <4 g/dL; (3) nPCR <1.2 g/kg/d and serum albumin level ≥4 g/dL; and (4) nPCR ≥1.2 g/kg/d and serum albumin level ≥4 g/dL. After adjustment for related variables, HD duration and nPCR ≥1.2 g/kg/d and serum albumin level <4 g/dL were positively correlated with CTS. By calculating the area under the receiver-operating characteristic curve, we calculated that the nPCR and HD duration cut-off points for obtaining the most favorable Youden index were 1.29 g/kg/d and 7.5 years, respectively. Advance multivariate logistic regression analysis revealed that in MHD patients, nPCR ≥1.29 g/kg/d and serum albumin <4 g/dL, and also HD duration >7.5 years were associated with CTS. A high nPCR and low serum albumin level, which likely reflect adequate nutrition and inflammation, were associated with CTS in MHD patients. PMID:27368039

  12. Association of a high normalized protein catabolic rate and low serum albumin level with carpal tunnel syndrome in hemodialysis patients

    PubMed Central

    Huang, Wen-Hung; Hsu, Ching-Wei; Weng, Cheng-Hao; Yen, Tzung-Hai; Lin, Jui-Hsiang; Lee, Meng

    2016-01-01

    Abstract Carpal tunnel syndrome (CTS) is the most common mononeuropathy in patients with end-stage renal disease (ESRD). The association between chronic inflammation and CTS in hemodialysis (HD) patients has rarely been investigated. HD patients with a high normalized protein catabolic rate (nPCR) and low serum albumin level likely have adequate nutrition and inflammation. In this study, we assume that a low serum albumin level and high nPCR is associated with CTS in HD patients. We recruited 866 maintenance hemodialysis (MHD) patients and divided them into 4 groups according to their nPCR and serum albumin levels: (1) nPCR <1.2 g/kg/d and serum albumin level <4 g/dL; (2) nPCR ≥1.2 g/kg/d and serum albumin level <4 g/dL; (3) nPCR <1.2 g/kg/d and serum albumin level ≥4 g/dL; and (4) nPCR ≥1.2 g/kg/d and serum albumin level ≥4 g/dL. After adjustment for related variables, HD duration and nPCR ≥1.2 g/kg/d and serum albumin level <4 g/dL were positively correlated with CTS. By calculating the area under the receiver-operating characteristic curve, we calculated that the nPCR and HD duration cut-off points for obtaining the most favorable Youden index were 1.29 g/kg/d and 7.5 years, respectively. Advance multivariate logistic regression analysis revealed that in MHD patients, nPCR ≥1.29 g/kg/d and serum albumin <4 g/dL, and also HD duration >7.5 years were associated with CTS. A high nPCR and low serum albumin level, which likely reflect adequate nutrition and inflammation, were associated with CTS in MHD patients. PMID:27368039

  13. [In vivo rheologic studies of plasma substitutes].

    PubMed

    Dewachter, P; Laxenaire, M C; Donner, M; Kurtz, M; Stoltz, J F

    1992-01-01

    The aim of this study was to compare in 60 ASA1 patients, the rheological effects of a 500 ml plasma substitute infusion at induction of general anaesthesia. The 60 patients were allocated into 6 groups of 10. Each group received either albumin 4%, or dextran 40 3.5%, or dextran 60 6%, or hydroxyethylstarch (HES) 200 6%, or modified fluid gelatin or Ringer lactate. The infusion extended over 30 minutes. In blood samples obtained before infusion, immediately after the end, three and 24 hours after the end of infusion, osmotic pressure, oncotic pressure, proteins and fibrinogen concentration were measured. Following rheological parameters were also assessed: plasma viscosity, blood viscosity at two shear rates (0.5 and 128 s-1), erythrocyte aggregation by primary and final aggregation times as well as total and partial dissociation thresholds. The determinations were carried out at haematocrit corrected to 40%. At intergroup analysis of the different substitutes compared to albumin 4%, with the exception of Ringer lactate, there was no significant modification of osmotic and oncotic pressures or fibrinogen concentrations. Only gelatin and dextran 60 modified the rheological parameters. The intragroup comparison did not demonstrate significant variations of osmotic and oncotic pressures. Fibrinogen concentrations remained unchanged up to the 24th hours, where they increased as a reaction to surgery. Similar changes of rheological parameters occurred for Ringer lactate, albumin 4% and dextran 40: decrease of plasma viscosity (< 10%) and blood viscosity (< 20% at shear rate of 0.5 s-1), increase of primary aggregation time (30-50%) with decrease of total dissociation threshold (10-20%). These changes ended 24 hours after infusion. Dextran 60 and gelatin elicited a modification of blood rheology until the 24th hour after the end of infusion. Such modifications did not occur with HES. It is concluded that when a rheological effect is required albumin 4% or dextran 40 3

  14. Preoperative neutrophil–lymphocyte ratio and fibrinogen level in patients distinguish between muscle-invasive bladder cancer and non-muscle-invasive bladder cancer

    PubMed Central

    Ma, Chengquan; Lu, Bingxin; Diao, Chengwen; Zhao, Kun; Wang, Xinpeng; Ma, Baojing; Lu, Baojian; Sun, Erlin

    2016-01-01

    Introduction The aim of this study was to explore if the preoperative neutrophil–lymphocyte ratio (NLR) and fibrinogen level can help in distinguishing between muscle-invasive bladder cancer (MIBC) and non-muscle-invasive bladder cancer (NMIBC). Methods We identified 669 patients who underwent surgery at our institution, and evaluated their preoperative NLRs and fibrinogen levels. Patients were divided into two groups, NMIBC (group-I) and MIBC (group-II), according to the postoperative pathology. For the intergroup comparison, data obtained from the two groups were evaluated using independent samples t-test. The cutoff value of the NLR, fibrinogen level, and integrated NLR and fibrinogen level was determined with receiver operating characteristic (ROC) curve. Results The mean NLRs of group-I and group-II were found as 2.71±2.46 and 4.66±8.00, respectively (P<0.001). The fibrinogen levels of the two groups were ~3.13±0.70 g/L and 3.41±0.84 g/L, respectively (P=0.001). Whether the NLR, fibrinogen level, and integrated NLR and fibrinogen level can help in distinguishing between MIBC and NMIBC was evaluated with ROC curve. The cutoff value of NLR was estimated as 2.01 according to the Youden index. With this value, sensitivity was found as 67.1%, specificity was 52.7%, and area under receiver operating characteristic (ROC) curve (AUC) was 0.601 (P=0.031). The cutoff value of fibrinogen level was estimated as 3.17 g/L according to the Youden index. Accordingly, sensitivity was found as 58%, specificity was 58%, and AUC was 0.60 (P=0.001). The cutoff value of integrated NLR and fibrinogen level was found as 0.166; the sensitivity was found as 86%, specificity was 42%, and AUC was 0.801 (P=0.01). Conclusion The data obtained in this study suggested that 67.1% of Ta-T1 tumors were likely to be invasive if the NLR was >2.01 and 58% were likely to be invasive if the fibrinogen level was >3.17 g/L. When we used both the NLR and fibrinogen level to distinguish between

  15. Fibrinogen-independent platelet adhesion and thrombus formation on subendothelium mediated by glycoprotein IIb-IIIa complex at high shear rate.

    PubMed Central

    Weiss, H J; Hawiger, J; Ruggeri, Z M; Turitto, V T; Thiagarajan, P; Hoffmann, T

    1989-01-01

    Platelet adhesion and thrombus formation on subendothelium, studied at a shear rate of 2,600 s-1, were inhibited by two synthetic peptides known to interact with GPIIb-IIIa. One peptide (HHLGGAKQAGDV) corresponds to the carboxyl terminal segment of the fibrinogen gamma-chain (gamma 400-411) and the other (RGDS) contains the amino acid sequence Arg-Gly-Asp (RGD) common to fibronectin, von Willebrand factor, vitronectin and the alpha-chain of fibrinogen. Neither platelet adhesion nor thrombus formation were decreased in a patient with severe congenital fibrinogen deficiency and this was equally true when his blood was further depleted of the small amounts of fibrinogen present utilizing an anti-fibrinogen antibody. In normal subjects, adhesion and thrombus formation were inhibited by the Fab' fragments of a monoclonal anti-GPIIb-IIIa antibody (LJ-CP8), which interferes with the interaction of platelets with all four adhesive proteins in both the fluid and solid phase. However, another anti-GPIIb-IIIa antibody (LJ-P5) that had minimal effects on the interaction of platelets with fibrinogen, but inhibited to varying degrees platelet interaction with other adhesive proteins, was equally effective. The findings demonstrate that, at a shear rate of 2,600 s-1, adhesive proteins other than fibrinogen are involved in GPIIb-IIIa-mediated platelet adhesion and thrombus formation on subendothelium. In addition, since LJ-P5 inhibited the binding of soluble von Willebrand factor and vitronectin, these adhesive proteins may be involved in platelet thrombus formation. In contrast to the results obtained at a shear rate of 2,600 s-1, fibrinogen could play a role in mediating platelet-platelet interactions with weak agonists or lower shear rates. PMID:2910912

  16. Effects of oral contraceptives, or lanosterol, on ADP-induced aggregation and binding of /sup 125/I-fibrinogen to rat platelets

    SciTech Connect

    McGregor, L.; Toor, B.; McGregor, J.L.; Renaud, S.; Clemetson, K.J.

    1984-03-01

    The aggregation to ADP and the binding of /sup 125/I-fibrinogen to platelets from rats treated with oral contraceptives or normal platelets treated in vitro with lanosterol were compared to their respective controls. Both types of platelets showed a significant increase in ADP-induced aggregation and in binding of fibrinogen, indicating that the effect of oral contraceptives could be partly due to increased levels of lanosterol in platelet membrane.

  17. Fabrication and physical and biological properties of fibrin gel derived from human plasma

    NASA Astrophysics Data System (ADS)

    Zhao, Haiguang; Ma, Lie; Zhou, Jie; Mao, Zhengwei; Gao, Changyou; Shen, Jiacong

    2008-03-01

    The fast development of tissue engineering and regenerative medicine drives the old biomaterials, for example, fibrin glue, to find new applications in these areas. Aiming at developing a commercially available hydrogel for cell entrapment and delivery, in this study we optimized the fabrication and gelation conditions of fibrin gel. Fibrinogen was isolated from human plasma by a freeze-thaw circle. Gelation of the fibrinogen was accomplished by mixing with thrombin. Absorbance of the fibrinogen/thrombin mixture at 550 nm as a function of reaction time was monitored by UV-VIS spectroscopy. It was found that the clotting time is significantly influenced by the thrombin concentration and the temperature, while less influenced by the fibrinogen concentration. After freeze-drying, the fibrin gel was characterized by scanning electron microscopy (SEM), revealing fibrous microstructure. Thermal gravimetric analysis found that the degradation temperature of the crosslinked fibrin gel starts from 288 °C, which is about 30 °C higher than that of the fibrinogen. The hydrogel has an initial water-uptake ratio of ~50, decreased to 30-40 after incubation in water for 11 h depending on the thrombin concentration. The fibrin gels lost their weights in PBS very rapidly, while slowly in DMEM/fetal bovine serum and DMEM. In vitro cell culture found that human fibroblasts could normally proliferate in the fibrin gel with spreading morphology. In conclusion, the fibrin gel containing higher concentration of fibrinogen (20 mg ml-1) and thrombin (5 U ml-1) has suitable gelation time and handling properties, and thus is applicable as a delivery vehicle for cells such as fibroblasts.

  18. Novel superhydrophilic poly(l-lactic acid-co-ε-caprolactone)/fibrinogen electrospun patch for rat abdominal wall reconstruction.

    PubMed

    Liu, Zhang; Li, Shaojie; Su, Ling; Sun, Kang; Wu, Xujun; Wu, Feng; Huang, Weihong; Yang, Li; Tang, Jianxiong; He, Hongbing

    2015-08-01

    A novel superhydrophilic hybrid scaffold was created by electrospinning a mixture of poly(l-lactic acid-co-ε-caprolactone) and formulated fibrinogen. The hybrid scaffolds possess the combined benefits of each individual component, such as moderate mechanical strength and excellent biocompatibility. In vitro studies also revealed that endothelial cells seeded on the hybrid scaffolds achieved a relatively high level of cell attachment after three days of culture and a significant increase in the proliferation rate after seven days of culture, compared with pure fibrinogen or poly(l-lactic acid-co-ε-caprolactone) scaffolds. A comparative study of hybrid and pure poly(l-lactic acid-co-ε-caprolactone) patches was performed in an abdominal wall defect model in rats. In both groups, implants degraded by six months, but muscle reconstruction was only observed in the hybrid patch group. PMID:25791683

  19. Rate of fibrinogen breakdown related to coronary patency and bleeding complications in patients with thrombolysis in acute myocardial infarction--results from the PRIMI trial.

    PubMed

    Ostermann, H; Schmitz-Huebner, U; Windeler, J; Bär, F; Meyer, J; van de Loo, J

    1992-09-01

    Four hundred and one patients with acute myocardial infarction of less than 4 h duration were randomized to receive intravenous thrombolytic treatment with either 80 mg of full length unglycosylated single-chain-urokinase plasminogen activator (INN saruplase) or 1.5 million IU of streptokinase delivered over a 60 min period. Angiographic patency rates were higher at 60 min in saruplase treated patients (71.8% vs 48%; P less than 0.001), but did not differ significantly at 90 min (71.2% vs 63.9%; P = 0.15). Fibrinogen levels dropped markedly in both groups, the decrease being delayed and less pronounced with saruplase. Total fibrin and fibrinogen degradation products and D-dimer values rose earlier and to higher peak values in streptokinase treated patients. In both groups marked plasminogen and alpha 2-antiplasmin consumption was observed. Lower fibrinogen levels, and in particular the faster rate of fibrinogen breakdown, were associated with higher patency rates at 90 min (P less than 0.05). Patients with bleeding complications had lower 'lowest points' and a more rapid decrease in fibrinogen (P less than 0.05). These findings were not related to the drug used. Increased heparin levels at 6 to 12 h were correlated to bleeding complications in streptokinase treated patients. It is concluded that the rate of fibrinogen breakdown during and following thrombolytic treatment for acute myocardial infarction is related to early vessel patency and bleeding complications. PMID:1396833

  20. The clearance of human fibrinogen fragments D1, D2, D3 and fibrin fragment D1 dimer in mice.

    PubMed

    Pizzo, S V; Pasqua, J J

    1982-10-01

    The clearance of human fibrinogen fragments D1, D2, D3 and fibrin fragment D1 dimer were studied in the mouse model. Clearance of these fragments is a complex process involving clearance from blood into three other compartments. The overall clearance of fragment D1 and its dimer were essentially identical. Fragments D2 and D3 cleared at a progressively slower rate. Competition studies were performed between 125I-labeled fragment D1 and large molar excesses of unlabeled human fragments D1, D2, D3, D1 dimer, fragment E, fibrinogen, macroalbumin, mannan and asialoorosomucoid. Of these ligands only the fragment D variants competed for the clearance of 125I-labeled fragment D1. Cross-competition was observed when 125I-labeled fragment D1 dimer was cleared in the presence of a large molar excesses of fragment D1. Autopsies demonstrated that injected fragments D1, D2, D3 and D1 dimer cleared primarily in liver and kidneys. In some clearance studies, livers were perfused with tissue culture fluid, subjected to light microscopic autoradiography, and silver grain counts performed to localize cleared fragment D1. These experiments indicated that 80% of the liver uptake was in hepatocytes. However, when silver grain counts were normalized for the number of parenchymal and nonparenchymal cells, the distribution of silver grains was essentially identical (1.8 and 1.6 grains per cells, respectively). It is concluded that fragments D1, D2, D3 and D1 dimer are recognized by a similar clearance pathway. Since neither fibrinogen nor fragment E competed for the clearance of fragment D1, it is suggested that determinants present in the fragment D domain become exposed after plasmin attack on fibrinogen and are responsible for clearance. PMID:7138910

  1. Introduction of the mec Element (Methicillin Resistance) into Staphylococcus aureus Alters In Vitro Functional Activities of Fibrinogen and Fibronectin Adhesins

    PubMed Central

    Vaudaux, Pierre E.; Monzillo, Vincenza; Francois, Patrice; Lew, Daniel P.; Foster, Tim J.; Berger-Bächi, Brigitte

    1998-01-01

    Some methicillin-resistant strains of Staphylococcus aureus are defective in the production of major surface components such as protein A, clumping factor, or other important adhesins to extracellular matrix components which may play a role in bacterial colonization and infection. To evaluate the impact of methicillin resistance (mec) determinants on bacterial adhesion mediated by fibrinogen or fibronectin adhesins, we compared the in vitro attachment of two genetically distinct susceptible strains (NCTC8325 and Newman) to protein-coated surfaces with that of isogenic methicillin-resistant derivatives. All strains containing an intact mec element in their chromosomes were found to be defective in adhesion to fibrinogen and fibronectin immobilized on polymethylmethacrylate coverslips, regardless of the presence or absence of additional mutations in the femA, femB, or femC gene, known to decrease expression of methicillin resistance in S. aureus. Western ligand affinity blotting or immunoblotting of cell wall-associated adhesins revealed similar contents of fibrinogen- or fibronectin-binding proteins in methicillin-resistant strains compared to those of their methicillin-susceptible counterparts. In contrast to methicillin-resistant strains carrying a mec element in their genomes, methicillin-resistant strains constructed in vitro, by introducing the mecA gene on a plasmid, retained their adhesion phenotypes. In conclusion, the chromosomal insertion of the mec element into genetically defined strains of S. aureus impairs the in vitro functional activities of fibrinogen or fibronectin adhesins without altering their production. This effect is unrelated to the activity of the mecA gene. PMID:9517933

  2. Associations of Toenail Selenium Levels With Inflammatory Biomarkers of Fibrinogen, High-Sensitivity C-Reactive Protein, and Interleukin-6

    PubMed Central

    Xun, Pengcheng; Liu, Kiang; Steven Morris, J.; Daviglus, Martha L.; Stevens, June; Jacobs, David R.; He, Ka

    2010-01-01

    The authors examined the associations of toenail selenium levels with blood concentrations of fibrinogen, high-sensitivity C-reactive protein (hs-CRP), and interleukin-6 (IL-6) in an 18-year follow-up study comprising 4,032 Americans aged 20–32 years at baseline (1987) from the Coronary Artery Risk Development in Young Adults (CARDIA) Trace Element Study. Toenail samples were collected in 1987, and selenium concentrations were measured by means of instrumental neutron-activation analysis. Fibrinogen level was analyzed in 1990, 1992, and 2005; hs-CRP was assessed in 1992, 2000, and 2005; and IL-6 was measured in 2005. After adjustment for potential confounders, no statistically significant associations between toenail selenium levels and any of the 3 inflammatory biomarkers were documented. Comparing the highest quintile of toenail selenium level with the lowest, odds ratios for elevated levels of fibrinogen (>460 mg/mL), hs-CRP (>3 μg/mL), and IL-6 (>3.395 pg/mL, 80th percentile) were 1.03 (95% confidence interval (CI): 0.77, 1.38; P for trend = 0.76), 1.02 (95% CI: 0.83, 1.27; P for trend = 0.92), and 0.98 (95% CI: 0.71, 1.36; P for trend = 0.82), respectively. Gender, race/ethnicity, smoking status, and selenium supplementation did not appreciably modify these results. This study found no associations between toenail selenium and inflammation as measured by fibrinogen, hs-CRP, and IL-6. PMID:20219762

  3. Effect of Cordycepin-Enriched WIB801C from Cordyceps militaris Suppressing Fibrinogen Binding to Glycoprotein IIb/IIIa

    PubMed Central

    Lee, Dong-Ha; Kim, Hyun-Hong; Lim, Deok Hwi; Kim, Jong-Lae; Park, Hwa-Jin

    2015-01-01

    In this study, we investigated the effects of cordycepin-enriched (CE)-WIB801C, a n-butanol extract of Cordyceps militaris-hypha on collagen-stimulated platelet aggregation. CE-WIB801C dose dependently inhibited collagen-induced platelet aggregation, and had a synergistic effect together with cordycepin (W-cordycepin) from CE-WIB801C on the inhibition of collagen-induced platelet aggregation. CE-WIB801C and cordycepin stimulated the phosphorylation of VASP (Ser157) and the dephosphorylation of PI3K and Akt, and inhibited the binding of fibrinogen to glycoprotein IIb/IIIa (αIIb/β3) and the release of ATP and serotonin in collagen-induced platelet aggregation. A-kinase inhibitor Rp-8-Br-cAMPS reduced CE-WIB801C-, and cordycepin-increased VASP (Ser157) phosphorylation, and increased CE-WIB801C-, and cordycepin-inhibited the fibrinogen binding to αIIb/β3. Therefore, we demonstrate that CE-WIB801C-, and cordycepin-inhibited fibrinogen binding to αIIb/β3 are due to stimulation of cAMP-dependent phosphorylation of VASP (Ser157), and inhibition of PI3K/Akt phosphorylation. These results strongly indicate that CE-WIB801C and cordycepin may have preventive or therapeutic potential for platelet aggregation-mediated diseases, such as thrombosis, myocardial infarction, atherosclerosis, and ischemic cerebrovascular disease. PMID:25593645

  4. Fibrinogen-related protein from amphioxus Branchiostoma belcheri is a multivalent pattern recognition receptor with a bacteriolytic activity.

    PubMed

    Fan, Chunxin; Zhang, Shicui; Li, Lei; Chao, Yeqing

    2008-07-01

    Fibrinogen-related proteins (FREPs) containing fibrinogen-like (FBG) domain have been shown to be involved in immune responses in both invertebrates and vertebrates, but the underlying mechanisms remain ill-defined. In this study we isolated a cDNA encoding amphioxus (Branchiostoma belcheri) FREP homolog, BbFREP. BbFREP encoded a protein of 286 amino acids, which included a C-terminal FBG domain and clustered together with human fibrinogen beta and gamma chains. Quantitative real time PCR revealed that the expression of BbFREP was significantly up-regulated following challenge with lipopolysaccharides (LPS) or lipoteichoic acid (LTA). The recombinant BbFREP expressed in Pichia pastoris was able to specifically recognize the pathogen-associated molecular patterns (PAMPs) on the bacterial surfaces including LPS, peptidoglycan (PGN) and LTA, and displayed strong bacteriolytic activities against both Gram-negative bacterium Escherichia coli and Gram-positive bacterium Staphylococcus aureus. BbFREP was also able to bind to both E. coli and S. aureus. In situ hybridization indicated that BbFREP was mainly expressed in the hepatic caecum and hind-gut, agreeing basically with the primary expression of vertebrate FREP genes in the liver. All these suggest that BbFREP can function as a pattern recognition receptor with a bacteriolytic activity via interaction with LPS, LTA and PGN. It also bolsters the notion that the hepatic caecum of amphioxus is equivalent to the vertebrate liver, acting as a major tissue in acute phase response. PMID:18533266

  5. Homozygosity for the E526V Mutation in Fibrinogen A Alpha-Chain Amyloidosis: The First Report

    PubMed Central

    Tavares, Isabel; Lobato, Luísa; Matos, Carlos; Santos, Josefina; Moreira, Paul; Saraiva, Maria João; Castro Henriques, António

    2015-01-01

    Systemic hereditary amyloidoses are autosomal dominant diseases associated with mutations in genes encoding ten different proteins. The clinical phenotype has implications on therapeutic approach, but it is commonly variable and largely dependent on the type of mutation. Except for rare cases involving gelsolin or transthyretin, patients are heterozygous for the amyloidogenic variants. Here we describe the first patient identified worldwide as homozygous for a nephropathic amyloidosis, involving the fibrinogen variant associated with the fibrinogen alpha-chain E526V (p.Glu545Val) mutation. In 1989, a 44-year-old woman presented with hypertension, hepatosplenomegaly, nephrotic syndrome, and renal failure. She started hemodialysis in 1990 and 6 years later underwent isolated kidney transplantation from a deceased donor. Graft function and clinical status were unremarkable for 16 years, despite progressively increased left ventricular mass on echocardiography. In 2012, 4 months before death, she deteriorated rapidly with severe heart failure, precipitated by Clostridium difficile colitis and urosepsis. Affected family members developed nephropathy, on average, nearly three decades later, which may be explained by the gene dosage effects on the phenotype of E526V (p.Glu545Val) fibrinogen A alpha-chain amyloidosis. PMID:26199771

  6. Cross-linked A alpha.gamma chain hybrids serve as unique markers for fibrinogen polymerized by tissue transglutaminase.

    PubMed Central

    Murthy, S N; Lorand, L

    1990-01-01

    Notwithstanding the high degree of amino acid sequence homologies between human factor XIIIa on the one hand and intracellular transglutaminases (protein-glutamine:amine gamma-glutamyltransferase, EC 2.3.2.13) from guinea pig liver or human erythrocytes on the other, we find that the two sets of enzymes differ remarkably in the mode of cross-linking the same protein substrate--i.e., human fibrinogen. In the program of polymerization with factor XIIIa, production of the known gamma-gamma' homologous chain pairs is the dominant feature, whereas with either intracellular transglutaminase, a series of hitherto unidentified A alpha.gamma hybrid chain combinations, designated A alpha p gamma q (p and q = 1, 2, 3...), is generated and practically no gamma-gamma' dimers are formed. Two-dimensional electrophoresis is particularly useful for demonstrating the production of A alpha p gamma q structures by protein staining as well as by immunoblotting against specific antibodies to the A alpha and gamma chains of fibrinogen. These findings should aid in deciding whether the direct cross-linking of fibrinogen by transglutaminase might contribute to thrombotic processes in addition to the thrombin- and factor XIIIa-dependent pathway of clot formation. Images PMID:1979874

  7. Multi Drug Loaded Thermo-Responsive Fibrinogen-graft-Poly(N-vinyl Caprolactam) Nanogels for Breast Cancer Drug Delivery.

    PubMed

    Rejinold, N Sanoj; Baby, Thejus; Chennazhi, K P; Jayakumar, R

    2015-03-01

    This study aims at the targeted delivery of 5-fluorouracil (5-FU) and Megestrol acetate (Meg) loaded fibrinogen-graft-poly(N-Vinyl caprolactam) nanogels (5-FU/Meg-fib-graft-PNVCL NGs) toward α5β1-integrins receptors expressed on breast cancer cells to have enhanced anti-cancer effect in vitro. To achieve this aim, we developed biocompatible thermoresponsive fib-graft-PNVCL NGs using fibrinogen and carboxyl terminated PNVCL via EDC/NHS amidation reaction. The Lower Critical Solution Temperature (LCST) of fib-graft-PNVCL could be tuned according to PNVCL/fibrinogen compositions. The 100-120 nm sized nanogels of fib-graft-PNVCL (LCST = 35 ?1 'C) was prepared using CaCl2 cross-linker. The 5-FU/Meg-fib-graft-PNVCL NGs showed a particle size of 150-170 nm size. The drug loading efficiency with 5-FU was 62% while Meg showed 74%. The 5-FU and Meg release was prominent above LCST than below LCST. The multi drug loaded fib-graft-PNVCL NGs showed enhanced toxicity, apoptosis and uptake by breast cancer (MCF-7) cells compared to their individual doses above their LCST. The in vivo assessment in Swiss albino mice showed sustained release of Meg and 5-FU as early as 3 days, confirming the therapeutic efficiency of the formulation. These results demonstrate an enhanced platform for the future animal studies on breast tumor xenograft model. PMID:26307823

  8. [Activity of Vegetative Nervous System and Levels of Inflammatory Cytokines During Glucose Tolerance Test in Subjects With Optimal and High Normal Blood Pressure].

    PubMed

    Mangileva, T A

    2015-01-01

    Fourteen patients with high normal (main group) and 15 subjects with optimal (control group) blood pressure (BP) were examined. Fasting and postprandial (60 and 120 min after oral intake of glucose) levels of glucose, insulin, interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and C-reactive protein were measured. At the same time spectral analysis of heart rate variability (HRV) was done. Body mass index (BMI) and insulin resistance index (as HOMA-IR) were calculated. In patients with high normal BP total power of HRV was decreased (p < 0.05) and dynamic changes of HRV after glucose loading were blunted. In persons with optimal BP transient elevation of low frequency component and low/high ratio in 60 min after onset of glucose tolerance test (GTT) were registered; values of both parameters were higher than in the main group (p < 0.05). Changes in vegetative nervous system activity in control group were accompanied by transient elevations of levels of inflammatory cytokines: IL-10 and TNF-α in 60 min, IL-6 in 120 min after GTT onset (p < 0.05), which at that moment were higher than in patients with high normal BP (p < 0.05). Fasting and postprandial insulin concentrations and glucose level 60 min after glucose intake were higher in patients from the main group (p < 0.05). In both groups positive correlations between BMI and HOMA-IR were observed (r1 = 0.70 & r2 = 0.78). Subjects with optimal and high normal BP have different variants of vegetative nervous system reactions to pulsatile hyperglycemia which is accompanied by changes of levels of inflammatory cytokines and worsening of carbohydrate metabolism in patients with high normal BP. PMID:26320287

  9. Haemostasis in Thyroid Surgery: Collagen-Fibrinogen-Thrombin Patch versus Cellulose Gauze—Our Experience

    PubMed Central

    Di Lascia, Alessandra; Lizzi, Vincenzo; Cianci, Pasquale; Fersini, Alberto; Ambrosi, Antonio; Neri, Vincenzo

    2016-01-01

    Purpose. Postoperative hemorrhage is fortunately uncommon but potentially life-threatening complication of thyroid surgery that increases the postoperative morbidity and the hospital stay. In this study we compare the efficacy of collagen patch coated with human fibrinogen and human thrombin (CFTP) (group C) and oxidized regenerated cellulose gauze (group B) versus traditional hemostatic procedures (group A) in thyroid surgery. Methods. From January 2011 to December 2013, 226 were eligible for our prospective, nonrandomized, comparative study. Patients requiring a video-assisted thyroidectomy without drain, “near total,” or hemithyroidectomy were excluded. Other exclusion criteria were a diagnosis of malignancy, substernal goiter, disorders of hemostasis or coagulation, and Graves or hyperfunctioning thyroid diseases. Outcomes included duration of operation, drainage volume, and postoperative complications. Results. Our results show a significant reduction in drainage volume in group C in comparison with the other two groups. In group C there was no bleeding but the limited numbers do not make this result significant. There were no differences in terms of other complications, except for the incidence of seroma in group B. Conclusion. The use of CFTP reduces the drainage volume, potentially the bleeding complications, and the hospital stay. These findings confirm the efficacy of CFTP, encouraging its use in thyroid surgery. PMID:27018148

  10. Adsorption and conformational modification of fibronectin and fibrinogen adsorbed on hydroxyapatite. A QCM-D study.

    PubMed

    Fernández-Montes Moraleda, Belén; San Román, Julio; Rodríguez-Lorenzo, Luís M

    2016-10-01

    Hydroxyapatite is a bioactive ceramic frequently used for bone engineering/replacement. One of the parameters that influence the biological response to implanted materials is the conformation of the first adsorbed protein layer. In this work, the adsorption and conformational changes of two fibroid serum proteins; fibronectin and fibrinogen adsorbed onto four different hydroxyapatite powders are studied with a Quartz Crystal Microbalance with Dissipation (QCM-D). Each of the calcined apatites adsorbs less protein than their corresponding synthesized samples. Adsorption on synthesized samples yields always an extended conformation whereas a reorganization of the layer is observed for the calcined samples. Fg acquires a "Side on" conformation in all the samples at the beginning of the experiment except for one of the synthesized samples where an "End-on" conformation is obtained during the whole experiment. The Extended conformation is the active conformation for Fn. This conformation is favored by apatites with large specific surface area (SSA) and on highly concentrated media. Apatite surface features should be considered in the selection or design of materials for bone regeneration, since it is possible to control the conformation mode of attachment of Fn and Fg by an appropriate selection of them. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2585-2594, 2016. PMID:27254464

  11. Correlating structure and function during the evolution of fibrinogen-related domains.

    PubMed

    Doolittle, Russell F; McNamara, Kyle; Lin, Kevin

    2012-12-01

    Fibrinogen-related domains (FReDs) are found in a variety of animal proteins with widely different functions, ranging from non-self recognition to clot formation. All appear to have a common surface where binding of one sort or other occurs. An examination of 19 completed animal genomes--including a sponge and sea anemone, six protostomes, and 11 deuterostomes--has allowed phylogenies to be constructed that show where various types of FReP (proteins containing FReDs) first made their appearance. Comparisons of sequences and structures also reveal particular features that correlate with function, including the influence of neighbor-domains. A particular set of insertions in the carboxyl-terminal subdomain was involved in the transition from structures known to bind sugars to those known to bind amino-terminal peptides. Perhaps not unexpectedly, FReDs with different functions have changed at different rates, with ficolins by far the fastest changing group. Significantly, the greatest amount of change in ficolin FReDs occurs in the third subdomain ("P domain"), the very opposite of the situation in most other vertebrate FReDs. The unbalanced style of change was also observed in FReDs from non-chordates, many of which have been implicated in innate immunity. PMID:23076991

  12. Interaction of fibrinogen and muramidase-released protein promotes the development of Streptococcus suis meningitis.

    PubMed

    Wang, Junping; Kong, Decong; Zhang, Shengwei; Jiang, Hua; Zheng, Yuling; Zang, Yating; Hao, Huaijie; Jiang, Yongqiang

    2015-01-01

    Muramidase-released protein (MRP) is as an important virulence marker of Streptococcus suis (S. suis) serotype 2. Our previous works have shown that MRP can bind human fibrinogen (hFg); however, the function of this interaction in S. suis meningitis is not known. In this study, we found that the deletion of mrp significantly impairs the hFg-mediated adherence and traversal ability of S. suis across human cerebral microvascular endothelial cells (hCMEC/D3). Measurement of the permeability to Lucifer yellow in vitro and Evans blue extravasation in vivo show that the MRP-hFg interaction significantly increases the permeability of the blood-brain barrier (BBB). In the mouse meningitis model, wild type S. suis caused higher bacterial loads in the brain and more severe histopathological signs of meningitis than the mrp mutant at day 3 post-infection. Western blot analysis and immunofluorescence observations reveal that the MRP-hFg interaction can destroy the cell adherens junction protein p120-catenin of hCMEC/D3. These results indicate that the MRP-hFg interaction is important in the development of S. suis meningitis. PMID:26441928

  13. αVβ3 Integrin Regulation of Respiratory Burst in Fibrinogen Adherent Human Neutrophils

    PubMed Central

    Kim, Hye-Yeong; Skokos, Eleni A.; Myer, Deborah J.; Agaba, Perez; Gonzalez, Anjelica L.

    2015-01-01

    In response to inflammatory stimuli, microvascular endothelial cells become activated, initiating the capture and exit of neutrophils from the blood vessel and into the extravascular extracellular matrix (ECM). In the extravascular space, neutrophils bind to ECM proteins, regulating cellular functions via signaling through adhesion molecules known as integrins. The αVβ3 integrin is an important mediator of neutrophil adhesion to ECM proteins containing the Arg-Gly-Asp (RGD) peptide sequence, including fibrinogen and fibronectin. Despite the abundance of RGD sequence in the ECM, adhesion molecule-mediated neutrophil activity has been focused on the β2 (Mac-1, CD11b/CD18) and β1 integrin response to matrix proteins. Here we investigated αVβ3 integrin-mediated reactive oxidant suppression as a consequence of human neutrophil adhesion to RGD containing proteins. Using integrin ligand-modified (poly)ethylene glycol hydrogels and reactive oxygen species (ROS) sensitive fluorescent probes (dihydrotetramethylrhosamine, H2TMRos), we evaluated integrin–peptide interactions that effectively regulate ROS generation. This study demonstrates that neutrophil adhesion suppresses ROS production in an αVβ3-dependent manner. Additionally, we determine that p38 mitogen-activated protein kinase in the respiratory burst signaling pathway is interrupted by integrin-mediated adhesion. These data indicate that ECM/integrin interactions can induce αVβ3-mediated adhesion dependent downstream signaling of ROS regulation via a Mac-1 independent mechanism. PMID:25632307

  14. [Comparison of thrombosis rate after laparoscopic and conventional interventions with the I(125) fibrinogen test].

    PubMed

    Kopánski, Z; Cienciała, A; Ulatowski, Z; Micherdziński, J

    1996-01-01

    The purpose of the present work was to compare the frequency of thrombosis in patients after laparoscopic and conventional operations. The diagnosis of thrombotic complications of the veins of the legs was determined by means of the I125 fibrinogen test. This isotopic test was chosen because it enables the early diagnosis of a thrombosis of the venous sinus of the calf at a stage at which no clinical symptoms have yet appeared. It was shown that in the group of patients submitted to laparoscopic intervention only 19 (18.8%) developed thrombotic complications out of the 101 patients, whereas in the group of conventionally operated patients 42 cases (45.7%) occurred in the 92 patients. Moreover, there was a statistically significant difference in the incidence of thrombotic complications in patients after laparoscopic cholecystectomy in comparison with the traditional operative method, with 14 cases (23.3%) out of 60 patients versus 35 (62.5%) out of 56 patients, respectively. PMID:8867483

  15. Differentiation of Human Mesenchymal Stem Cells Toward Quality Cartilage Using Fibrinogen-Based Nanofibers.

    PubMed

    Forget, Jeremy; Awaja, Firas; Gugutkov, Dencho; Gustavsson, Juhan; Gallego Ferrer, Gloria; Coelho-Sampaio, Tatiana; Hochman-Mendez, Camila; Salmeron-Sánchez, Manuel; Altankov, George

    2016-09-01

    Mimicking the complex intricacies of the extra cellular matrix including 3D configurations and aligned fibrous structures were traditionally perused for producing cartilage tissue from stem cells. This study shows that human adipose derived mesenchymal stem cells (hADMSCs) establishes significant chondrogenic differentiation and may generate quality cartilage when cultured on 2D and randomly oriented fibrinogen/poly-lactic acid nanofibers compared to 3D sandwich-like environments. The adhering cells show well-developed focal adhesion complexes and actin cytoskeleton arrangements confirming the proper cellular interaction with either random or aligned nanofibers. However, quantitative reverse transcription-polymerase chain reaction analysis for Collagen 2 and Collagen 10 genes expression confirms favorable chondrogenic response of hADMSCs on random nanofibers and shows substantially higher efficacy of their differentiation in 2D configuration versus 3D constructs. These findings introduce a new direction for cartilage tissue engineering through providing a simple platform for the routine generation of transplantable stem cells derived articular cartilage replacement that might improve joint function. PMID:27276166

  16. Platelet Rich Plasma and Knee Surgery

    PubMed Central

    Sánchez, Mikel; Sánchez, Pello; Orive, Gorka; Anitua, Eduardo; Padilla, Sabino

    2014-01-01

    In orthopaedic surgery and sports medicine, the knee joint has traditionally been considered the workhorse. The reconstruction of every damaged element in this joint is crucial in achieving the surgeon's goal to restore the knee function and prevent degeneration towards osteoarthritis. In the last fifteen years, the field of regenerative medicine is witnessing a boost of autologous blood-derived platelet rich plasma products (PRPs) application to effectively mimic and accelerate the tissue healing process. The scientific rationale behind PRPs is the delivery of growth factors, cytokines, and adhesive proteins present in platelets and plasma, as well as other biologically active proteins conveyed by the plasma such as fibrinogen, prothrombin, and fibronectin; with this biological engineering approach, new perspectives in knee surgery were opened. This work describes the use of PRP to construct and repair every single anatomical structure involved in knee surgery, detailing the process conducted in ligament, meniscal, and chondral surgery. PMID:25302310

  17. Effects of two different fibric acid derivatives on lipoproteins, cholesteryl ester transfer, fibrinogen, plasminogen activator inhibitor and paraoxonase activity in type IIb hyperlipoproteinaemia.

    PubMed

    Durrington, P N; Mackness, M I; Bhatnagar, D; Julier, K; Prais, H; Arrol, S; Morgan, J; Wood, G N

    1998-05-01

    We have investigated the effects of two fibric acid derivatives, bezafibrate mono (400 mg daily) and gemfibrozil (600 mg b.d.), in 29 patients with type IIb hyperlipoproteinaemia. All patients received placebo and each drug for 8 weeks in randomised order in a double-blind, cross-over study designed to evaluate any different effects of the drugs on serum lipoproteins, cholesteryl ester transfer protein (CETP), cholesteryl ester transfer activity (CETA), plasma fibrinogen, plasminogen activator inhibitor-I (PAI-1) or paraoxonase. Serum cholesterol decreased (P < 0.05) with gemfibrozil, but the effect of bezafibrate on serum cholesterol did not achieve statistical significance (placebo 8.34 +/- 1.05 (mean +/- S.D.), gemfibrozil 7.70 +/- 1.23 and bezafibrate 7.8 +/- 1.37 mmol/l). Both drugs decreased the serum triglyceride concentration (both P < 0.001) (placebo 4.39 (3.13-5.75) (median (interquartile range)), bezafibrate 2.26 (1.89-3.89) and gemfibrozil 2.00 (1.30-3.30) mmol/l) and very low density lipoprotein (VLDL) cholesterol (both P < 0.001) (placebo 1.18 (0.74-2.30), bezafibrate 0.59 (0.34-0.85) and gemfibrozil 0.48 (0.34-0.68) mmol/l). Discontinuous gradient ultracentrifugation (DGU) revealed that Sf 60-400 (large VLDL) decreased by more than 50% and Sf 20-60 (small VLDL) by more than 30% with each of the drugs (both P < 0.001), neither of which affected the composition of these lipoproteins. Gemfibrozil decreased the concentration of Sf 12-20 lipoprotein (intermediate density lipoprotein; IDL) by 23% (P < 0.01), whereas the effect of bezafibrate on this lipoprotein did not achieve statistical significance. Neither drug altered the concentration of apolipoprotein B or of total Sf 0-12 lipoproteins (low density lipoprotein, (LDL)). Both, however, significantly increased the quantity of free cholesterol in Sf 0-12 lipoproteins (P < 0.05). Overall the concentration of triglycerides decreased significantly in all lipoproteins isolated by DGU (Sf 0-12, Sf 12-20, Sf

  18. Exposure of the lysine in the gamma chain dodecapeptide of human fibrinogen is not enhanced by adsorption to poly(ethylene terephthalate) as measured by biotinylation and mass spectrometry.

    PubMed

    Ovod, Vitaliy; Scott, Evan A; Flake, Megan M; Parker, Stanley R; Bateman, Randall J; Elbert, Donald L

    2012-03-01

    Conformational changes in adsorbed fibrinogen may enhance the exposure of platelet adhesive sites that are inaccessible in solution. To test this hypothesis, mass spectrometric methods were developed to quantify chemical modification of lysine residues following adsorption of fibrinogen to biomaterials. The quantitative method used an internal standard consisting of isotope-labeled fibrinogen secreted by human HepG2 cells in culture. Lysine residues in the internal standard were partially reacted with NHS-biotin. For the experimental samples, normal human fibrinogen was adsorbed to poly(ethylene terephthalate) (PET) particles. The adsorbed fibrinogen was reacted with NHS-biotin and then eluted from the particles. Constant amounts of internal standard were added to sample fibrinogen and analyzed by liquid chromatography/tandem mass spectrometry. Biotinylation of the lysine residue in the platelet-adhesive gamma chain dodecapeptide (GCDP) was quantified by comparison with the internal standard. Approximately 80% of the GCDP peptides were biotinylated when fibrinogen was reacted with NHS-biotin in solution or adsorbed onto PET. These results are generally consistent with previous antibody binding studies and suggest that other regions of fibrinogen may be crucial in promoting platelet adhesion to materials. The results do not directly address but are consistent with the hypothesis that only activated platelets adhere to adsorbed fibrinogen. PMID:22213354

  19. Pharmacokinetic study of the structural components of adenosine diphosphate-encapsulated liposomes coated with fibrinogen γ-chain dodecapeptide as a synthetic platelet substitute.

    PubMed

    Taguchi, Kazuaki; Ujihira, Hayato; Ogaki, Shigeru; Watanabe, Hiroshi; Fujiyama, Atsushi; Doi, Mami; Okamura, Yosuke; Takeoka, Shinji; Ikeda, Yasuo; Handa, Makoto; Otagiri, Masaki; Maruyama, Toru

    2013-08-01

    Fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV, H12)-coated, ADP-encapsulated liposomes [H12-(ADP)-liposomes] were developed as a synthetic platelet alternative that specifically accumulates at bleeding sites as the result of interactions with activated platelets via glycoprotein IIb/IIIa and augments platelet aggregation by releasing ADP. The aim of this study is to characterize the pharmacokinetic properties of H12-(ADP)-liposomes and structural components in rats, and to predict the blood retention of H12-(ADP)-liposomes in humans. With use of H12-(ADP)-liposomes in which the encapsulated ADP and liposomal membrane cholesterol were radiolabeled with (14)C and (3)H, respectively, it was found that the time courses for the plasma concentration curves of (14)C and (3)H radioactivity showed that the H12-(ADP)-liposomes remained intact in the blood circulation for up to 24 hours after injection, and were mainly distributed to the liver and spleen. However, the (14)C and (3)H radioactivity of H12-(ADP)-liposomes disappeared from organs within 7 days after injection. The encapsulated ADP was metabolized to allantoin, which is the final metabolite of ADP in rodents, and was mainly eliminated in the urine, whereas the cholesterol was mainly eliminated in feces. In addition, the half-life of the H12-(ADP)-liposomes in humans was predicted to be approximately 96 hours from pharmacokinetic data obtained for mice, rats, and rabbits using an allometric equation. These results suggest that the H12-(ADP)-liposome has potential with proper pharmacokinetic and acceptable biodegradable properties as a synthetic platelet substitute. PMID:23735758

  20. Improved fibronectin-immobilized fibrinogen microthreads for the attachment and proliferation of fibroblasts

    PubMed Central

    Rajangam, Thanavel; An, Seong Soo A

    2013-01-01

    The aim of this study was to fabricate fibrinogen (Fbg) microfibers with different structural characteristics for the development of 3-D tissue-engineering scaffolds. Fabricated Fbg microfibers were investigated for their biomolecule encapsulation, cell adhesion, and proliferations. Microfibers with three different concentrations of Fbg (5, 10, and 15 wt%) were prepared by a gel solvent-extraction method using a silicone rubber tube. Fbg microfibers were covalently modified with fibronectin (FN) by using water-soluble 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as the cross-linking agent. Fbg microfibers were characterized by their FN cross-linking properties, structural morphology, and in vitro degradation. Furthermore, FN/Fbg microfibers were evaluated for cell attachment and proliferation. The bio-compatibility and cell proliferation of the microfibers were assessed by measuring adenosine triphosphate activity in C2C12 fibroblast cells. Cell attachment and proliferation on microfibers were further examined using fluorescence and scanning electron microscopic images. FN loading on the microfibers was confirmed by fluorescence and infrared spectroscopy. Surface morphology was characterized by scanning electron microscopy, and showed highly aligned nanostructures for fibers made with 15 wt% Fbg, a more porous structure for fibers made with 10 wt% Fbg, and a less porous structure for those made with 5 wt% Fbg. Controlled biodegradation of the fiber was observed for 8 weeks by using an in vitro proteolytic degradation assay. Fbg microfibers with highly aligned nanostructures (15 wt%) showed enhanced biomolecule encapsulation, as well as higher cell adhesion and proliferation than another two types of FN/Fbg fibers (5 and 10 wt%) and unmodified Fbg fibers. The promising results obtained from the present study reveal that optimal structure of Fbg microfibers could be used as a potential substratum for growth factors or drug release, especially in wound healing and

  1. Adhesins of Leptospira interrogans Mediate the Interaction to Fibrinogen and Inhibit Fibrin Clot Formation In Vitro

    PubMed Central

    Oliveira, Rosane; Domingos, Renan F.; Siqueira, Gabriela H.; Fernandes, Luis G.; Souza, Natalie M.; Vieira, Monica L.; de Morais, Zenaide M.; Vasconcellos, Silvio A.; Nascimento, Ana L. T. O.

    2013-01-01

    We report in this work that Leptospira strains, virulent L. interrogans serovar Copenhageni, attenuated L. interrogans serovar Copenhageni and saprophytic L. biflexa serovar Patoc are capable of binding fibrinogen (Fg). The interaction of leptospires with Fg inhibits thrombin- induced fibrin clot formation that may affect the haemostatic equilibrium. Additionally, we show that plasminogen (PLG)/plasmin (PLA) generation on the surface of Leptospira causes degradation of human Fg. The data suggest that PLA-coated leptospires were capable to employ their proteolytic activity to decrease one substrate of the coagulation cascade. We also present six leptospiral adhesins and PLG- interacting proteins, rLIC12238, Lsa33, Lsa30, OmpL1, rLIC11360 and rLIC11975, as novel Fg-binding proteins. The recombinant proteins interact with Fg in a dose-dependent and saturable fashion when increasing protein concentration was set to react to a fix human Fg concentration. The calculated dissociation equilibrium constants (KD) of these reactions ranged from 733.3±276.8 to 128±89.9 nM for rLIC12238 and Lsa33, respectively. The interaction of recombinant proteins with human Fg resulted in inhibition of fibrin clot by thrombin-catalyzed reaction, suggesting that these versatile proteins could mediate Fg interaction in Leptospira. Our data reveal for the first time the inhibition of fibrin clot by Leptospira spp. and presents adhesins that could mediate these interactions. Decreasing fibrin clot would cause an imbalance of the coagulation cascade that may facilitate bleeding and help bacteria dissemination PMID:24009788

  2. Association of Soluble Fibrinogen-like Protein 2 with the Severity of Coronary Artery Disease.

    PubMed

    Cheng, Jing; Chen, Yingying; Xu, Banglong; Wu, Jixiong; He, Fei

    2016-01-01

    Objective The purpose of this study was to investigate the relationship between circulating soluble fibrinogen-like protein 2 (sFGL2) concentrations and the severity of coronary artery disease (CAD) in patients who underwent first-time angiography for suspected CAD. Methods Serum sFGL2 concentrations were measured in 102 consecutive patients by an enzyme-linked immunosorbent assay (ELISA). The number of circulating CD4(+)CD25(+)CD127(low) T regulatory cells (Tregs) was determined by flow cytometry and effecter cytokines, including transforming growth factor-β1 and interleukin-10 (IL-10), were also evaluated by an ELISA. Associations between sFGL2 and Tregs with angiographic indexes of the severity of CAD (i.e., number of diseased vessels and the modified Gensini score) were estimated. Results The sFGL2 levels in patients with angiographically confirmed CAD were significantly lower than those in patients with normal coronary arteries (26.95±8.53 vs. 9.88±5.46 ng/mL, p<0.001). Significant correlations were observed between the serum sFGL2 level and number of diseased vessels (r=-0.860, p<0.001) and modified Gensini score (r=-0.833, p<0.001). Using a multivariate analysis, the serum sFGL2 level was independently associated with the presence and severity of CAD. Conclusion The serum sFGL2 levels are significantly lower in the presence of CAD and correlate with the severity of the disease. Further clinical studies are needed to confirm the use of sFGL2 as a biomarker for the detection and extent of CAD. PMID:27580532

  3. pH Dependence of Adsorbed Fibrinogen Conformation and Its Effect on Platelet Adhesion.

    PubMed

    Hu, Yu; Jin, Jing; Liang, Haojun; Ji, Xiangling; Yin, Jinghua; Jiang, Wei

    2016-04-26

    Quartz crystal microbalance with dissipation (QCM-D) and dual polarization interferometry (DPI) were used to investigate fibrinogen (Fib) adsorption behavior on different surfaces by changing the pH value. Moreover, integrin adhesion to the adsorbed Fibs was studied using DPI. Qualitative and quantitative studies of platelet adhesion to the adsorbed Fibs were performed using scanning electron microscopy (SEM), confocal laser scanning microscope (CLSM), and released lactate dehydrogenase (LDH) assay. Experimental results indicated that the conformation and orientation of the absorbed Fibs depended on surface property and pH cycling. For the hydrophilic surface, Fibs adsorbed at pH 7.4 and presented a αC-hidden orientation. As a result, no integrin adhesion was observed, and a small number of platelets were adhered because the αC-domains were hidden under the Fib molecule. By changing the rinsing solution pH from 7.4 to 3.2 and then back to 7.4, the adsorbed Fib orientation became αC-exposed via the transformation of Fib conformation during pH cycling. Therefore, integrin adhesion was more likely to occur, and more platelets were adhered and activated. For the hydrophobic surface, the adsorbed Fibs became more spread and stretched due to the strong interaction between the Fibs and surface. αC-exposed orientation remained unchanged when the rinsing solution pH changed from 7.4 to 3.2 and then back to 7.4. Therefore, a large number of integrins and platelets were adhered to the adsorbed Fibs, and almost all of the adhered platelets were activated. PMID:27035056

  4. Adsorption of human fibrinogen and albumin onto hydrophobic and hydrophilic Ti6Al4V powder

    NASA Astrophysics Data System (ADS)

    Rodríguez-Sánchez, Jesús; Gallardo-Moreno, Amparo M.; Bruque, José M.; González-Martín, M. Luisa

    2016-07-01

    Adsorption of proteins on solid surfaces has been widely studied because of its importance in various biotechnological, medical and technical applications, such as medical implants or biosensors. One of the main problems is the adsorption-induced conformational changes because they often modify the biological activity of the proteins, which is believed to be a key factor on the subsequent cellular adhesion. The aim of this work is the study of the adsorption of human fibrinogen (Fg) and human serum albumin (HSA) onto Ti6Al4V particles, commercially available on different size, that are used to elaborate scaffolds to provide structural support to cell proliferation, promoting tissue development and bone regeneration among others. The study was done through the analysis of the adsorption isotherms and the electrical characterization of surfaces after adsorption in terms of the zeta potential (ζ). From this analysis it seems that Fg adsorbs preferentially vertically oriented (end-on) and HSA moves sequentially over the surface of the Ti6Al4V particles through dimmer formation, allowing adsorption progress over this initial bilayer. The zeta potential values of both proteins remain constant when the monolayer is formed. The study also extends the analysis of both adsorption behaviour and ζ potential characterization factors to the influence of the substrate hydrophobicity as this property can be modified for the Ti6Al4V by irradiating it with ultraviolet light (UV-C) without changes on its chemical composition [1,2]. Differences at low protein concentrations were found for both isotherms and zeta-potential values.

  5. Biomechanical Comparison of Glutaraldehyde-Crosslinked Gelatin Fibrinogen Electrospun Scaffolds to Porcine Coronary Arteries.

    PubMed

    Tamimi, E; Ardila, D C; Haskett, D G; Doetschman, T; Slepian, M J; Kellar, R S; Vande Geest, J P

    2016-01-01

    Cardiovascular disease (CVD) is the leading cause of death for Americans. As coronary artery bypass graft surgery (CABG) remains a mainstay of therapy for CVD and native vein grafts are limited by issues of supply and lifespan, an effective readily available tissue-engineered vascular graft (TEVG) for use in CABG would provide drastic improvements in patient care. Biomechanical mismatch between vascular grafts and native vasculature has been shown to be the major cause of graft failure, and therefore, there is need for compliance-matched biocompatible TEVGs for clinical implantation. The current study investigates the biaxial mechanical characterization of acellular electrospun glutaraldehyde (GLUT) vapor-crosslinked gelatin/fibrinogen cylindrical constructs, using a custom-made microbiaxial optomechanical device (MOD). Constructs crosslinked for 2, 8, and 24 hrs are compared to mechanically characterized porcine left anterior descending coronary (LADC) artery. The mechanical response data were used for constitutive modeling using a modified Fung strain energy equation. The results showed that constructs crosslinked for 2 and 8 hrs exhibited circumferential and axial tangential moduli (ATM) similar to that of the LADC. Furthermore, the 8-hrs experimental group was the only one to compliance-match the LADC, with compliance values of 0.0006±0.00018 mm Hg-1 and 0.00071±0.00027 mm Hg-1, respectively. The results of this study show the feasibility of meeting mechanical specifications expected of native arteries through manipulating GLUT vapor crosslinking time. The comprehensive mechanical characterization of cylindrical biopolymer constructs in this study is an important first step to successfully develop a biopolymer compliance-matched TEVG. PMID:26501189

  6. Cloning, sequencing, and expression of a fibronectin/fibrinogen-binding protein from group A streptococci.

    PubMed Central

    Courtney, H S; Li, Y; Dale, J B; Hasty, D L

    1994-01-01

    Lipoteichoic acid and several streptococcal proteins have been reported to bind fibronectin (Fn) or fibrinogen (Fgn), which may serve as host receptors. We searched for such proteins by screening a library of genes from M type 5 group A streptococci cloned into Escherichia coli. Lysates of clones were probed with biotinylated Fn and biotinylated Fgn. One clone expressed a 54-kDa protein that reacted with Fn and Fgn. The protein, termed FBP54, was purified and used to immunize rabbits. Anti-FBP54 serum reacted with purified, recombinant FBP54 and with a protein of similar electrophoretic mobility in extracts of M type 5, 6, and 24 streptococci. Anti-FBP54 serum also reacted with 5 of 15 strains of intact, live streptococci, suggesting that FBP54 may be a surface antigen. Southern blot analysis confirmed that the gene is found in group A streptococci but not in Staphylococcus aureus or E. coli. The cloned gene was sequenced and contained an open reading frame encoding a protein with a calculated molecular weight of 54,186. Partial amino acid sequencing of purified FBP54 confirmed that this open reading frame encoded the protein. As determined by utilizing fusion proteins containing truncated forms of FBP54, the primary Fn/Fgn-binding domain appears to be contained in residues 1 to 89. These data suggest that FBP54 may be a surface protein of streptococci that reacts with both Fn and Fgn and therefore may participate in the adhesion of group A streptococci to host cells. Images PMID:8063411

  7. Targeted disruption of fibrinogen like protein-1 accelerates hepatocellular carcinoma development

    SciTech Connect

    Nayeb-Hashemi, Hamed; Desai, Anal; Demchev, Valeriy; Bronson, Roderick T.; Hornick, Jason L.; Cohen, David E.; Ukomadu, Chinweike

    2015-09-18

    Fibrinogen like protein-1 (Fgl1) is a predominantly liver expressed protein that has been implicated as both a hepatoprotectant and a hepatocyte mitogen. Fgl1 expression is decreased in hepatocellular carcinoma (HCC) and its loss correlates with a poorly differentiated phenotype. To better elucidate the role of Fgl1 in hepatocarcinogenesis, we treated mice wild type or null for Fgl1 with diethyl nitrosamine and monitored for incidence of hepatocellular cancer. We find that mice lacking Fgl1 develop HCC at more than twice the rate of wild type mice. We show that hepatocellular cancers from Fgl1 null mice are molecularly distinct from those of the wild type mice. In tumors from Fgl1 null mice there is enhanced activation of Akt and downstream targets of the mammalian target of rapamycin (mTOR). In addition, there is paradoxical up regulation of putative hepatocellular cancer tumor suppressors; tripartite motif-containing protein 35 (Trim35) and tumor necrosis factor super family 10b (Tnfrsf10b). Taken together, these findings suggest that Fgl1 acts as a tumor suppressor in hepatocellular cancer through an Akt dependent mechanism and supports its role as a potential therapeutic target in HCC. - Highlights: • Fgl1 knockout mice (Fgl1KO) are more prone to carcinogen-induced liver cancer compared to wild type (WT) mates. • Tumors from the Fgl1KO are molecularly distinct with enhanced Akt and mTOR activity in comparison with Fgl1WT tumors. • Tumors from the Fgl1KO have enhanced expression of Trim35 and Tnfrsf10b, putative HCC tumor suppressors.

  8. The 894T allele of endothelial nitric oxide synthase gene is related to left ventricular mass in African Americans with high-normal blood pressure.

    PubMed Central

    Lapu-Bula, Rigobert; Quarshie, Alexander; Lyn, Deborah; Oduwole, Adefisayo; Pack, Cheryl; Morgan, Jan; Nkemdiche, Sunday; Igho-Pemu, Priscilla; Onwuanyi, Anekwe; Li, Rongling; Ofili, Elizabeth

    2005-01-01

    BACKGROUND AND OBJECTIVES: The 894T allele in exon 7 of the endothelial nitric oxide synthase (eNOS) gene has been inconsistently associated with hypertension in different racial groups. Because high-normal blood pressure (BP) confers an increased risk for the development of hypertension and other cardiovascular disorders, including left ventricular hypertrophy (LVH), we tested the hypothesis that the allelic variation (894T) in the eNOS gene would directly correlate with alterations in LV mass (LVM) in individuals with high-normal BP. METHODS: Genotype distribution of G894T was compared between 20 African Americans (10 females/10 males) with high-normal BP (systolic BP of 130-139 and/or diastolic BP of 85-89 mmHg) and 64 counterparts (37 females/27 males) with normal BP (<130/85 mmHg). Echocardiographic LVM was calculated (Devereux formula) and indexed to body surface area to define the presence of LVH (LVMI >134/110 g/m2 for men/women). RESULTS: For the entire group, the 894T allelic frequencies (15, 48%) and G894T genotype distributions were consistent with the Hardy-Weinberg equilibrium expectations (estimated disequilibrium coefficient = 0.0118, P=0.40). LVMI was significantly higher in homozygous carriers (TT) of the rare 894T allele (n = 3 females/0 males) than in heterozygous GT (n = 13 females/7 males) and individuals bearing the GG (n=34 females/27 males) variant (124 +/- 70 vs. 82 +/- 24 and 82 +/- 19 g/m2, respectively, P < 0.05). The observed relationship between eNOS 894T allele and LVMI was restricted to individuals with high-normal BP (r = 0.94, P = 0.03) but not in those with normal BP (r = 0.39, P =0.64), by analysis of variance (ANOVA) after adjusting for age, gender, body mass index, smoking and systolic BP. CONCLUSION: These findings, not previously described, provide important preliminary evidence to suggest an increased susceptibility to LVH in African Americans who carry the 894T variant of the eNOS gene and have high-normal blood pressure

  9. Structural basis for distinctive recognition of fibrinogen [gamma]C peptide by the platelet integrin [alpha][subscript IIb][beta]3

    SciTech Connect

    Springer, Timothy A.; Zhu, Jianghai; Xiao, Tsan

    2009-01-12

    Hemostasis and thrombosis (blood clotting) involve fibrinogen binding to integrin {alpha}{sub IIb}{beta}{sub 3} on platelets, resulting in platelet aggregation. {alpha}{sub v}{beta}{sub 3} binding fibrinogen via an Arg-Asp-Gly (RGD) motif in fibrinogen's {alpha} subunit. {alpha}{sub IIb}{beta}{sub 3} also binds to fibrinogen; however, it does so via an unstructured RGD-lacking C-terminal region of the {gamma} subunit ({gamma}C peptide). These distinct modes of fibrinogen binding enable {alpha}{sub IIb}{beta}{sub 3} and {alpha}{sub v}{beta}{sub 3} to function cooperatively in hemostasis. In this study, crystal structures reveal the integrin {alpha}{sub IIb}{beta}{sub 3}-{gamma}C peptide interface, and, for comparison, integrin {alpha}{sub IIb}{beta}{sub 3} bound to a lamprey {gamma}C primordial RGD motif. Compared with RGD, the GAKQAGDV motif in {gamma}C adopts a different backbone configuration and binds over a more extended region. The integrin metal ion-dependent adhesion site (MIDAS) Mg{sup 2+} ion binds the {gamma}C Asp side chain. The adjacent to MIDAS (ADMIDAS) Ca{sup 2+} ion binds the {gamma}C C terminus, revealing a contribution for ADMIDAS in ligand binding. Structural data from this natively disordered {gamma}C peptide enhances our understanding of the involvement of {gamma}C peptide and integrin {alpha}{sub IIb}{beta}{sub 3} in hemostasis and thrombosis.

  10. Novel osteoinductive photo-cross-linkable chitosan-lactide-fibrinogen hydrogels enhance bone regeneration in critical size segmental bone defects

    PubMed Central

    Kim, Sungwoo; Bedigrew, Katherine; Guda, Teja; Maloney, William J.; Park, Sangwon; Wenke, Joseph C.; Yang, Yunzhi Peter

    2014-01-01

    The purpose of this study was to develop and characterize a novel photo-cross-linkable chitosan-lactide-fibrinogen (CLF) hydrogel and evaluate the efficacy of bone morphogenetic protein-2 (BMP-2) containing CLF hydrogel for osteogenesis in vitro and in vivo. We synthesized the CLF hydrogels and characterized their chemical structure, degradation rate, compressive modulus, and in vitro BMP-2 release kinetics. We evaluated bioactivities of the BMP-2 containing CLF hydrogels (0, 50, 100, and 500 ng/ml) in vitro using W-20-17 preosteoblast mouse bone marrow stromal cells and C2C12 mouse myoblast cells. The effect of BMP-2 containing CLF gels (0, 0.5, 1, 2, and 5μg) on bone formation was evaluated using rat critical size segmental bone defects for 4 weeks. FTIR spectra and SEM images showed chemical and structural changes by addition of fibrinogen into chitosan-lactide copolymer. Incorporation of fibrinogen molecules significantly increased compressive modulus of the hydrogels. In vitro BMP-2 release study showed initial burst releases from the CLF hydrogels followed by sustained releases, regardless of the concentration of the BMP-2 over 4 weeks. Cells in all groups were viable in the presence of the hydrogels regardless of BMP-2 doses, indicating non-cytotoxicity of hydrogels. Alkaline phosphate activity and mineralization of cells exhibited dose dependence on BMP-2 containing CLF hydrogels. Radiographs, microcomputed tomography, and histology confirmed that the BMP-2 containing CLF hydrogels prompted neo-osteogenesis and accelerated healing of the defects in a dose-dependent manner. Thus the CLF hydrogel is a promising delivery system of growth factors for bone regeneration. PMID:25174669

  11. Contribution of the Interaction of Streptococcus mutans Serotype k Strains with Fibrinogen to the Pathogenicity of Infective Endocarditis

    PubMed Central

    Nomura, Ryota; Otsugu, Masatoshi; Naka, Shuhei; Teramoto, Noboru; Kojima, Ayuchi; Muranaka, Yoshinori; Matsumoto-Nakano, Michiyo; Ooshima, Takashi

    2014-01-01

    Streptococcus mutans, a pathogen responsible for dental caries, is occasionally isolated from the blood of patients with bacteremia and infective endocarditis (IE). Our previous study demonstrated that serotype k-specific bacterial DNA is frequently detected in S. mutans-positive heart valve specimens extirpated from IE patients. However, the reason for this frequent detection remains unknown. In the present study, we analyzed the virulence of IE from S. mutans strains, focusing on the characterization of serotype k strains, most of which are positive for the 120-kDa cell surface collagen-binding protein Cbm and negative for the 190-kDa protein antigen (PA) known as SpaP, P1, antigen I/II, and other designations. Fibrinogen-binding assays were performed with 85 clinical strains classified by Cbm and PA expression levels. The Cbm+/PA− group strains had significantly higher fibrinogen-binding rates than the other groups. Analysis of platelet aggregation revealed that SA31, a Cbm+/PA− strain, induced an increased level of aggregation in the presence of fibrinogen, while negligible aggregation was induced by the Cbm-defective isogenic mutant SA31CBD. A rat IE model with an artificial impairment of the aortic valve created using a catheter showed that extirpated heart valves in the SA31 group displayed a prominent vegetation mass not seen in those in the SA31CBD group. These findings could explain why Cbm+/PA− strains are highly virulent and are related to the development of IE, and the findings could also explain the frequent detection of serotype k DNA in S. mutans-positive heart valve clinical specimens. PMID:25287921

  12. Comparative study of the C3d receptor and 58-kilodalton fibrinogen-binding mannoproteins of Candida albicans.

    PubMed Central

    López-Ribot, J L; Martínez, J P; Chaffin, W L

    1995-01-01

    Using polyclonal antibodies (PAbs) raised against the Candida albicans C3d receptor (CR2; PAb anti-CR2) and the 58-kDa fibrinogen-binding mannoprotein (mp58; PAb anti-mp58) as well as ligand interactions, we have studied the relationship between these two receptors. In an indirect immunofluorescence assay with germ tubes, greater intensity was observed on the mother blastoconidium when PAb anti-CR2 was used, whereas greater intensity was localized to the hyphal extension when PAb anti-mp58 or binding of soluble fibrinogen was used. No competition or change in the fluorescence pattern was observed in dual-labeling experiments with PAb anti-CR2 and either fibrinogen or PAb anti-mp58. Binding competition also was not observed in an enzyme-linked immunosorbent assay using the components present in a beta-mercaptoethanol extract from the cell wall of germ tubes. In immunoblots, PAb anti-CR2 recognized three different discrete bands with apparent molecular masses of 21, 40, and 66 kDa in the beta-mercaptoethanol extracts from the cell wall, whereas a different, single, broader band with an apparent molecular mass of 58 kDa was detected with PAb anti-mp58. However, when nondenaturing conditions were used to separate the materials present in the cell wall extracts, no reactivity could be detected on Western blots (immunoblots) with PAb anti-mp58. When PAb anti-CR2 was used for analysis, a single band migrating in the area corresponding to approximately 40 kDa was detected. These observations suggest a higher molecular weight for mp58 and one or more of the components detected with PAb anti-CR2 in their native state. PMID:7768591

  13. Fibrinogen cleavage by the Streptococcus pyogenes extracellular cysteine protease and generation of antibodies that inhibit enzyme proteolytic activity.

    PubMed

    Matsuka, Y V; Pillai, S; Gubba, S; Musser, J M; Olmsted, S B

    1999-09-01

    The extracellular cysteine protease from Streptococcus pyogenes is a virulence factor that plays a significant role in host-pathogen interaction. Streptococcal protease is expressed as an inactive 40-kDa precursor that is autocatalytically converted into a 28-kDa mature (active) enzyme. Replacement of the single cysteine residue involved in formation of the enzyme active site with serine (C192S mutation) abolished detectable proteolytic activity and eliminated autocatalytic processing of zymogen to the mature form. In the present study, we investigated activity of the wild-type (wt) streptococcal protease toward human fibrinogen and bovine casein. The former is involved in blood coagulation, wound healing, and other aspects of hemostasis. Treatment with streptococcal protease resulted in degradation of the COOH-terminal region of fibrinogen alpha chain, indicating that fibrinogen may serve as an important substrate for this enzyme during the course of human infection. Polyclonal antibodies generated against recombinant 40- and 28-kDa (r40- and r28-kDa) forms of the C192S streptococcal protease mutant exhibited high enzyme-linked immunosorbent assay titers but demonstrated different inhibition activities toward proteolytic action of the wt enzyme. Activity of the wt protease was readily inhibited when the reaction was carried out in the presence of antibodies generated against r28-kDa C192S mutant. Antibodies produced against r40-kDa C192S mutant had no significant effect on proteolysis. These data suggest that the presence of the NH(2)-terminal prosegment prevents generation of functionally active antibodies and indicate that inhibition activity of antibodies most likely depends on their ability to bind the active-site region epitope(s) of the protein. PMID:10456870

  14. Fibrinogen Cleavage by the Streptococcus pyogenes Extracellular Cysteine Protease and Generation of Antibodies That Inhibit Enzyme Proteolytic Activity

    PubMed Central

    Matsuka, Yury V.; Pillai, Subramonia; Gubba, Siddeswar; Musser, James M.; Olmsted, Stephen B.

    1999-01-01

    The extracellular cysteine protease from Streptococcus pyogenes is a virulence factor that plays a significant role in host-pathogen interaction. Streptococcal protease is expressed as an inactive 40-kDa precursor that is autocatalytically converted into a 28-kDa mature (active) enzyme. Replacement of the single cysteine residue involved in formation of the enzyme active site with serine (C192S mutation) abolished detectable proteolytic activity and eliminated autocatalytic processing of zymogen to the mature form. In the present study, we investigated activity of the wild-type (wt) streptococcal protease toward human fibrinogen and bovine casein. The former is involved in blood coagulation, wound healing, and other aspects of hemostasis. Treatment with streptococcal protease resulted in degradation of the COOH-terminal region of fibrinogen α chain, indicating that fibrinogen may serve as an important substrate for this enzyme during the course of human infection. Polyclonal antibodies generated against recombinant 40- and 28-kDa (r40- and r28-kDa) forms of the C192S streptococcal protease mutant exhibited high enzyme-linked immunosorbent assay titers but demonstrated different inhibition activities toward proteolytic action of the wt enzyme. Activity of the wt protease was readily inhibited when the reaction was carried out in the presence of antibodies generated against r28-kDa C192S mutant. Antibodies produced against r40-kDa C192S mutant had no significant effect on proteolysis. These data suggest that the presence of the NH2-terminal prosegment prevents generation of functionally active antibodies and indicate that inhibition activity of antibodies most likely depends on their ability to bind the active-site region epitope(s) of the protein. PMID:10456870

  15. Relationship of CRP, IL-6, and Fibrinogen with Right Ventricular Structure and Function: The MESA-Right Ventricle Study

    PubMed Central

    Harhay, Michael O.; Tracy, Russell; Bagiella, Emilia; Barr, R. Graham; Pinder, Diane; Hundley, W. Gregory; Bluemke, David A.; Kronmal, Richard A.; Lima, Joao A. C.; Kawut, Steven M.

    2013-01-01

    Background/objectives Inflammation contributes to the pathogenesis of disease associated with the left ventricle (LV); yet, our understanding of the effect of inflammation on the right ventricle (RV) is quite limited. Methods and results The relationships of C-reactive protein (CRP), interleukin-6 (IL-6) and fibrinogen with RV morphology and function (from cardiac MRI) were examined in participants free of clinical cardiovascular disease (n=4,009) from the Multi-Ethnic Study of Atherosclerosis (MESA)-RV study. Multivariable regressions (linear, quantile [25th and 75th] and generalized additive models [GAM]) were used to examine the independent association of CRP, IL-6 and fibrinogen with RV mass, RV end-diastolic volume (RVEDV), RV end-systolic volume (RVESV), RV stroke volume (RVSV) and RV ejection fraction (RVEF). Unadjusted and adjusted analyses revealed strong inverse associations between both CRP and IL-6 with RV mass, RVEDV, RVESV and RVSV (all p<0.01); there were no associations with RVEF. These relationships remained significant after adjustment for the respective LV parameters and lung function. However, GAM models suggested that extreme values of CRP and IL-6 might have positive associations with RV parameters. Fibrinogen showed significant associations in unadjusted models, but no associations after adjustment or in sensitivity analyses. Conclusion Levels of CRP and IL-6 are independently associated with RV morphology even after adjustment for the respective LV measure in this multi-ethnic population free of cardiovascular disease. Systemic inflammation may contribute to RV structural changes independent of effects on the LV. PMID:23932860

  16. Interaction study of bioactive molecules with fibrinogen and human platelets determined by 1H NMR relaxation experiments.

    PubMed

    Bonechi, Claudia; Martini, Silvia; Rossi, Claudio

    2009-02-15

    In order to investigate the interaction processes between bioactive molecules and macromolecular receptors NMR methodology based on the analysis of selective and non-selective spin-lattice relaxation rate enhancements of ligand protons was used. The contribution from the bound ligand fraction to the observed relaxation rate in relation to macromolecular target concentration allowed the calculation of the normalized affinity index[A(I)(N)](L)(T) in which the effects of motional anisotropies and different proton densities have been removed. In this paper, we applied this methodology to investigate the affinity of epinephrine and isoproterenol towards two different systems: fibrinogen and platelets. PMID:19157885

  17. [A novel molecular marker for thrombus formation and life prognosis--clinical usefulness of measurement of soluble fibrin monomer-fibrinogen complex (SF)].

    PubMed

    Koga, Shin

    2004-04-01

    plasma, it would serve as a strong tool to selectively kick up the state of thrombin generation. These results indicate that the SF could be a specific and reliable parameter for the diagnosis of DIC and contribute to legitimate managements of patients with DIC. The excessive life response to serious clinical insults, such as sepsis, severe pancreatitis, trauma and shock, is called systemic inflammatory response syndrome (SIRS). Once SIRS occurs, people may often die from serious complications such as adult respiratory distress syndrome (ARDS), acute lung injury (ALI), disseminated intravascular coagulation (DIC) and multiple organ failure (MOF). Especially, ALI followed by pneumoniae associated with SIRS could depend on patient's prognosis and life. That is to say, it seems to be urgent for clinicians to make differential diagnosis between Pneumoniae associated with SIRS and Coagulopathy (PASC) and Simple Pneumoniae (SP). Soluble fibrin monomer-fibrinogen complex(SF) is formed in the early-activated state of blood coagulation. Thus such a molecular complex is expected to serve as a parameter for the diagnosis of coagulopathy, in particular its early stage. The aim of the present study is to make differential diagnosis between Pneumoniae associated with SIRS and Coagulopathy (PASC) and Simple Pneumoniae(SP) by using a newly developed SF test utilizing an SF specific monoclonal antibody (IF-43). We measured SF together with established other parameters, hemogram, blood laboratory items in 7 patients with PASC and 17 patients with SP. The diagnosis of Pneumoniae was defined according to the criteria: clinical symptoms abnormal shadow in both Chest X-p and Chest CT, increased level of CRP, number of WBC. The diagnosis of SIRS was based on the criteria established by American College of Chest Physicians (ACCP)/Society of Critical Care Medicine (SCCM) Consensus Conference held in August of 1991 in Northbrook, IL (USA). Underlying disease includes leukemias, malignant lymphoma

  18. The influence of high-normal testosterone levels on risk-taking in healthy males in a 1-week letrozole administration study.

    PubMed

    Goudriaan, Anna E; Lapauw, Bruno; Ruige, Johannes; Feyen, Els; Kaufman, Jean-Marc; Brand, Matthias; Vingerhoets, Guy

    2010-10-01

    Human studies on the relation between testosterone levels and risk-taking behaviour are scarce. Related functions, like aggression, have been related to higher testosterone levels more consistently, especially in the animal literature. Estradiol affects several neurotransmitter systems that play a role in behaviour regulation. Existing human studies on neurocognitive functions and testosterone levels have largely ignored the interrelatedness of testosterone levels and estradiol levels. Therefore, in this study, the effects of a 1-week combined testosterone and estradiol intervention on risk-taking behaviours were investigated. Twenty-one healthy men, with a normal body mass index, were treated for 7 days with an aromatase inhibitor (letrozole 2.5 mg), resulting in high-normal levels of testosterone and low-normal levels of estradiol, or with a combination of an aromatase inhibitor and estradiol (75 μg/24 h), resulting in low-normal levels of testosterone and high-normal levels of estradiol. A randomized experimenter and participant-blind controlled design was applied. Neurocognitive measures of risk-taking and reward and punishment sensitivity were assessed before starting with the medication and after 7 days of drug administration: Balloon Analogue Risk Task (BART), Game of Dice Task (GDT), and Iowa Gambling Task (IGT). A group by time effect was present for the BART, indicating that the high-normal testosterone group showed an increase in risk-taking on the BART, from the first drug-naive BART performance, to the second BART performance (aromatase inhibitor), whereas such an increase was not present in the low-normal testosterone/high estradiol group. No group by time interactions were present in GDT or IGT performance. These results implicate that testosterone levels in healthy men are associated with increased risk-taking under conditions of unknown probabilities, but not in conditions of known probabilities (GDT) or of strategic decision making (IGT). PMID

  19. Pathogen reduction in human plasma using an ultrashort pulsed laser.

    PubMed

    Tsen, Shaw-Wei D; Kingsley, David H; Kibler, Karen; Jacobs, Bert; Sizemore, Sara; Vaiana, Sara M; Anderson, Jeanne; Tsen, Kong-Thon; Achilefu, Samuel

    2014-01-01

    Pathogen reduction is a viable approach to ensure the continued safety of the blood supply against emerging pathogens. However, the currently licensed pathogen reduction techniques are ineffective against non-enveloped viruses such as hepatitis A virus, and they introduce chemicals with concerns of side effects which prevent their widespread use. In this report, we demonstrate the inactivation of both enveloped and non-enveloped viruses in human plasma using a novel chemical-free method, a visible ultrashort pulsed laser. We found that laser treatment resulted in 2-log, 1-log, and 3-log reductions in human immunodeficiency virus, hepatitis A virus, and murine cytomegalovirus in human plasma, respectively. Laser-treated plasma showed ≥70% retention for most coagulation factors tested. Furthermore, laser treatment did not alter the structure of a model coagulation factor, fibrinogen. Ultrashort pulsed lasers are a promising new method for chemical-free, broad-spectrum pathogen reduction in human plasma. PMID:25372037

  20. Pathogen Reduction in Human Plasma Using an Ultrashort Pulsed Laser

    PubMed Central

    Tsen, Shaw-Wei D.; Kingsley, David H.; Kibler, Karen; Jacobs, Bert; Sizemore, Sara; Vaiana, Sara M.; Anderson, Jeanne; Tsen, Kong-Thon; Achilefu, Samuel

    2014-01-01

    Pathogen reduction is a viable approach to ensure the continued safety of the blood supply against emerging pathogens. However, the currently licensed pathogen reduction techniques are ineffective against non-enveloped viruses such as hepatitis A virus, and they introduce chemicals with concerns of side effects which prevent their widespread use. In this report, we demonstrate the inactivation of both enveloped and non-enveloped viruses in human plasma using a novel chemical-free method, a visible ultrashort pulsed laser. We found that laser treatment resulted in 2-log, 1-log, and 3-log reductions in human immunodeficiency virus, hepatitis A virus, and murine cytomegalovirus in human plasma, respectively. Laser-treated plasma showed ≥70% retention for most coagulation factors tested. Furthermore, laser treatment did not alter the structure of a model coagulation factor, fibrinogen. Ultrashort pulsed lasers are a promising new method for chemical-free, broad-spectrum pathogen reduction in human plasma. PMID:25372037

  1. Effect of zinc on the interaction between fibrinogen and platelet glycoprotein IIb/IIIa (GPIIb/IIIa)

    SciTech Connect

    Trybulec, M.; Cook, J.J.; Niewiarowski, S. )

    1991-03-11

    In the present study, the authors tested the effect of Zn++ on the interaction between fibrinogen (Fg) and its platelet membrane receptor in three different systems. (1) Fg binding to ADP-stimulated platelets showed a pronounced elevation in the presence of 1 mM zinc. Scatchard analysis of this data revealed a significant increase in the number of Fg binding sites, however, binding affinity was not changed. This increase was only partially blocked by a GPIIb/IIIa complex-specific monoclonal antibody (A{sub 2}A{sub 9}). (2) Zn++ enhanced Fg-induced aggregation of chymotrypsin-treated platelets. (3) Zn++ but not Mn++ or MG++, increased binding of purified GPIIb/IIIa to Fg immobilized on the ELISA plate in the presence of 0.5 mM calcium. The same extent of binding occurred even in the absence of calcium provided that Zn++ was present. A{sub 2}A{sub 9} antibody only partially blocked this reaction. The authors propose that zinc-induced changes in the structure of GPIIb/IIIa complex make the receptor more available to fibrinogen.

  2. Fibrinogen variant B[beta]D432A has normal polymerization but does not bind knob 'B'

    SciTech Connect

    Bowley, Sheryl R.; Lord, Susan T.

    2009-10-23

    Fibrinogen residue B{beta}432Asp is part of hole 'b' that interacts with knob 'B,' whose sequence starts with Gly-His-Arg-Pro-amide (GHRP). Because previous studies showed B{beta}D432A has normal polymerization, we hypothesized that B{beta}432Asp is not critical for knob 'B' binding and that new knob-hole interactions would compensate for the loss of this Asp residue. To test this hypothesis, we solved the crystal structure of fragment D from B{beta}D432A. Surprisingly, the structure (rfD-B{beta}D432A+GH) showed the peptide GHRP was not bound to hole 'b.' We then re-evaluated the polymerization of this variant by examining clot turbidity, clot structure, and the rate of FXIIIa cross-linking. The turbidity and the rate of - dimer formation for B{beta}D432A were indistinguishable compared with normal fibrinogen. Scanning electron microscopy showed no significant differences between the clots of B{beta}D432A and normal, but the thrombin-derived clots had thicker fibers than clots obtained from batroxobin, suggesting that cleavage of FpB is more important than 'B:b' interactions. We conclude that hole 'b' and 'B:b' knob-hole binding per se have no influence on fibrin polymerization.

  3. Aberrant hepatic processing causes removal of activation peptide and primary polymerisation site from fibrinogen Canterbury (A alpha 20 Val --> Asp).

    PubMed Central

    Brennan, S O; Hammonds, B; George, P M

    1995-01-01

    A novel mechanism of molecular disease was uncovered in a patient with prolonged thrombin time and a mild bleeding tendency. DNA sequencing of the fibrinogen A alpha chain indicated heterozygosity for a mutation of 20 Val --> Asp. The molar ratio of fibrinopeptide A to B released by thrombin was substantially reduced at 0.64 suggesting either impaired cleavage or that the majority of the variant alpha chains lacked the A peptide. The latter novel proposal arises from the observation that the mutation changes the normal 16R G P R V20 sequence to R G P R D creating a potential furin cleavage site at Arg 19. Synthetic peptides incorporating both sequences were tested as substrates for both thrombin and furin. There was no substantial difference in the thrombin catalyzed cleavage. However, the variant peptide, but not the normal, was rapidly cleaved at Arg 19 by furin. Predictably intracellular cleavage of the Aalpha-chain at Arg 19 would remove fibrinopeptide A together with the G P R polymerisation site. This was confirmed by sequence analysis of fibrinogen Aalpha chains after isolation by SDS-PAGE. The expected normal sequence was detected together with a new sequence (D V E R H Q S A-) commencing at residue 20. Truncation was further verified by nonreducing SDS-PAGE of the NH2-terminal disulfide knot which indicated the presence of aberrant homo- and heterodimers. Images PMID:8675656

  4. A comparison between radioimmunoassay and other immunological techniques for the measurement of fibrinogen/fibrin degradation products in serum.

    PubMed

    Ratky, S M; Martin, M J; Gordon, Y B; Baker, L R; Chard, T; Leslie, J

    1975-06-01

    Fibrinogen/fibrin degradation products (FDP) have been measured in serum by radioimmunoassay for fragment E (FgE), one of the terminal fragments in plasmic digestion of fibrinogen, and the results compared with those determined by both a tanned red cell haemagglutination inhibiton immunoassay (TRCHII) and a latex particle agglutination inhibition immunoassay. The detection limit of the FgE assay was 0.8 ng/ml, that of TRCHII was 625 ng/ml and the latex particle agglunitaion inhibition immunoassay was 10 mug/ml. All the samples measured had detectable levels of FDP with the FgE assay, whereas only 88% were measurable with the TRCHII and 2% by the latex particle agglutination inhibition immunoassay. A comparison of those samples giving a positive result with both the TRCHII and FgE assay showed overall agreement between the results of the two types of assay, but there was considerable scatter of FgE levels at each point of the TRCHII. The major advantages of the radioimmunoassay system are greater sensitivity, specificity and reproducibility. PMID:1201206

  5. Fibrin glue from stored human plasma. An inexpensive and efficient method for local blood bank preparation.

    PubMed

    Spotnitz, W D; Mintz, P D; Avery, N; Bithell, T C; Kaul, S; Nolan, S P

    1987-08-01

    European surgeons have used fibrin glue extensively during thoracic, cardiovascular, and general surgical operations. Until now, however, it has been available only as a commercial preparation made from pooled human plasma, and it has not been approved by the U.S. Food and Drug Administration for use in the United States because of a high associated risk of hepatitis and acquired immune deficiency syndrome. Methods of obtaining fibrinogen, an essential component of fibrin glue, from cryoprecipitate or fresh frozen plasma have been published recently. However, the cryoprecipitate method results in relatively low concentrations of fibrinogen, which can reduce glue effectiveness. The fresh frozen plasma method is more expensive and does not meet the standards of the American Association of Blood Banks for the "closed" system required for safe handling and management of blood component products. Both the cryoprecipitate and the fresh frozen plasma methods result in waste of unstable clotting factors. These factors are necessary to replace human plasma clotting deficiencies but are not necessary for the production of fibrin glue. The authors have developed an efficient, high-concentration blood bank method for producing and maintaining a local supply of a safer and less expensive but equally effective material derived from stored human plasma. This material is produced using approved blood bank techniques for a "closed" system in blood component production, thus reducing the risks of contamination and infection, and its fibrinogen concentration is higher than that of standard cryoprecipitate. The cost of 1 unit of this fibrin glue is comparable to that for 1 unit of cryoprecipitate and less than that for 1 unit of fresh frozen plasma.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2440358

  6. Recurring Extracorporeal Circuit Clotting During Continuous Renal Replacement Therapy Resolved after Single-Session Therapeutic Plasma Exchange

    PubMed Central

    Fülöp, Tibor; Cosmin, Adrian; Juncos, Luis A.

    2011-01-01

    We report a case of a 17 year old white male with multiple fractures and multi-organ failure who developed oliguric acute renal failure requiring continuous renal replacement therapy. Repeated clotting of the extracorporeal circuit (ECC) prevented delivery of a minimally acceptable dose of renal replacement therapy despite adequate anticoagulation and dialysis catheter exchanges. Evaluation for a primary hypercoagulable state was negative, but his fibrinogen was elevated (1,320 mg/dL, normal range: 150–400 mg/dL), likely induced by his severe inflammatory state. A single session of therapeutic plasma exchange (TPE) with albumin and normal saline replacement was performed with subsequent drop in fibrinogen to 615 mg/dL. No further episodes of premature ECC clotting occurred, suggesting plasma factor(s) removed may have contributed to the clinical hypercoagulable state. TPE may play an adjunctive role in select cases of recurrent ECC clotting refractory to current anticoagulation techniques. PMID:21618596

  7. Fibrinogen α-chain-derived peptide is upregulated in hippocampus of rats exposed to acute morphine injection and spontaneous alternation testing

    PubMed Central

    Maki, Agatha E; Morris, Kenneth A; Catherman, Kasia; Chen, Xian; Hatcher, Nathan G; Gold, Paul E; Sweedler, Jonathan V

    2014-01-01

    Fibrinogen is a secreted glycoprotein that is synthesized in the liver, although recent in situ hybridization data support its expression in the brain. It is involved in blood clotting and is released in the brain upon injury. Here, we report changes in the extracellular levels of fibrinogen α-chain-derived peptides in the brain after injections of saline and morphine. More specifically, in order to assess hippocampus-related working memory, an approach pairing in vivo microdialysis with mass spectrometry was used to characterize extracellular peptide release from the hippocampus of rats in response to saline or morphine injection coupled with a spontaneous alternation task. Two fibrinopeptide A-related peptides derived from the fibrinogen α-chain – fibrinopeptide A (ADTGTTSEFIEAGGDIR) and a fibrinopeptide A-derived peptide (DTGTTSEFIEAGGDIR) – were shown to be consistently elevated in the hippocampal microdialysate. Fibrinopeptide A was significantly upregulated in rats exposed to morphine and spontaneous alternation testing compared with rats exposed to saline and spontaneous alternation testing (P < 0.001), morphine alone (P < 0.01), or saline alone (P < 0.01), respectively. The increase in fibrinopeptide A in rats subjected to morphine and a memory task suggests that a complex interaction between fibrinogen and morphine takes place in the hippocampus. PMID:24855564

  8. Thrombin-induced conversion of fibrinogen to fibrin results in rapid platelet trapping which is not dependent on platelet activation or GPIb

    PubMed Central

    Jarvis, Gavin E; Atkinson, Ben T; Frampton, Jon; Watson, Steve P

    2003-01-01

    Activation of human platelets by thrombin is mediated by the proteolytic cleavage of two G-protein coupled protease-activated receptors, PAR-1 and PAR-4. However, thrombin also binds specifically to the platelet surface glycoprotein GPIb. It has been claimed that thrombin can induce aggregation of platelets via a novel GPIb-mediated pathway, which is independent of PAR activation and fibrinogen binding to αIIbβ3 integrin, but dependent upon polymerizing fibrin and the generation of intracellular signals. In the presence of both fibrinogen and the αIIbβ3 receptor antagonist lotrafiban, thrombin induced a biphasic platelet aggregation response. The initial primary response was small but consistent and associated with the release of platelet granules. The delayed secondary response was more substantial and was abolished by the fibrin polymerization blocking peptide GPRP. Cleavage of the extracellular portion of GPIb by mocarhagin partially inhibited thrombin-induced αIIbβ3-dependent aggregation and release, but had no effect on the secondary fibrin-dependent response. Fixing of the platelets abolished αIIbβ3-dependent aggregation and release of adenine nucleotides, whereas the fibrin-dependent response remained, indicating that platelet activation and intracellular signalling are not necessary for this secondary ‘aggregation'. In conclusion, the secondary fibrin-dependent ‘aggregation' response observed in the presence of fibrinogen and lotrafiban is a platelet trapping phenomenon dependent primarily on the conversion of soluble fibrinogen to polymerizing fibrin by thrombin. PMID:12598411

  9. Affinity purification and characterization of a fibrinogen-binding protein complex which protects mice against lethal challenge with Streptococcus equi subsp. equi.

    PubMed

    Meehan, M; Nowlan, P; Owen, P

    1998-04-01

    Cell-wall-associated proteins from Streptococcus equi subsp. equi, the causative agent of strangles, were analysed with a view to identifying a potential protective antigen. Preparations of these proteins, isolated from mutanolysin extracts of cell walls, were shown to contain one major high-M(r) protein species (apparent M(r) 220,000 and 550,000 when analysed by SDS-PAGE and gel-filtration chromatography, respectively). The high-M(r) protein bound horse fibrinogen and was purified under non-denaturing conditions using fibrinogen affinity chromatography. The fibrinogen-binding protein (FgBP) reacted with serum taken from horses recovering from strangles and protected mice against lethal challenge from S. equi subsp. equi. The sequence of the corresponding gene (fbp) was determined and shown to encode a mature protein (M(r) 54,597) with predicted coiled-coil structure. An FgBP truncate, lacking the C-terminal cell wall/membrane anchor domain, was overexpressed in and purified from Escherichia coli and was shown to behave in an analogous fashion to the wild-type product in terms of M(r) estimation, fibrinogen binding and seroreactivity. PMID:9579073

  10. PM-IRRAS investigation of the interaction of serum albumin and fibrinogen with a biomedical-grade stainless steel 316LVM surface.

    PubMed

    Desroches, Marie J; Chaudhary, Nida; Omanovic, Sasha

    2007-09-01

    Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was applied to investigate the interaction of bovine serum albumin (BSA) and fibrinogen with a biomedical-grade 316LVM stainless steel surface, in terms of the adsorption thermodynamics and adsorption-induced secondary structure changes of the proteins. Highly negative apparent Gibbs energy of adsorption values revealed a spontaneous adsorption of both proteins onto the surface, accompanied by significant changes in their secondary structure. It was determined that, at saturated surface coverages, lateral interactions between the adsorbed BSA molecules induced rather extensive secondary structure changes. Fibrinogen's two coiled coils appeared to undergo negligible secondary structure changes upon adsorption of the protein, while large structural rearrangements of the protein's globular domains occurred upon adsorption. The secondary structure of adsorbed fibrinogen was not influenced by lateral interactions between the adsorbed fibrinogen molecules. PM-IRRAS was deemed to be viable for investigating protein adsorption and for obtaining information on adsorption-induced changes in their secondary structures. PMID:17715960

  11. Adsorption of fibrinogen on a biomedical-grade stainless steel 316LVM surface: a PM-IRRAS study of the adsorption thermodynamics, kinetics and secondary structure changes.

    PubMed

    Desroches, Marie-Josee; Omanovic, Sasha

    2008-05-14

    Polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS) was employed to investigate the interaction of serum protein fibrinogen with a biomedical-grade 316LVM stainless steel surface, in terms of the adsorption thermodynamics, kinetics and secondary structure changes of the protein. Apparent Gibbs energy of adsorption values indicated a highly spontaneous and strong adsorption of fibrinogen onto the surface. The kinetics of fibrinogen adsorption were successfully modeled using a pseudo first-order kinetic model. Deconvolution of the amide I bands indicated that the adsorption of fibrinogen on 316LVM results in significant changes in the protein's secondary structure that occur predominantly within the first minute of adsorption. Among the investigated structures, the alpha-helix structure undergoes the smallest changes, while the beta-sheet and beta-turns structures undergo significant changes. It was shown that lateral interactions between the adsorbed molecules do not play a role in controlling the secondary structure changes. An increase in temperature induced changes in the secondary structure of the protein, characterized by a loss of the alpha-helical content and its transformation into the beta-turns structure. PMID:18446250

  12. A Bovine Fibrinogen-Enriched Fraction as a Source of Peptides with in Vitro Renin and Angiotensin-I-Converting Enzyme Inhibitory Activities.

    PubMed

    Lafarga, Tomas; Rai, Dilip K; O'Connor, Paula; Hayes, Maria

    2015-10-01

    Bovine fibrinogen is currently used in the food industry as a binding agent in restructured meat products. However, this protein is underused as a source of bioactive peptides. In this study, a number of novel angiotensin-I-converting enzyme (ACE-I) and renin inhibitory peptides were identified and enriched from a bovine fibrinogen fraction. Fibrinogen was isolated and enriched from bovine blood and hydrolyzed with the food-grade enzyme papain, which was selected for use using in silico analysis. The generated hydrolysate was subjected to ultrafiltration and its peptide profile characterized by liquid chromatography-tandem mass spectrometry. A number of peptides were identified and chemically synthesized to confirm their bioactivity in vitro. Identified peptides included the multifunctional tripeptide SLR, corresponding to f(35-37) of the β-chain of bovine fibrinogen with ACE-I and renin IC50 values of 0.17 and 7.2 mM, respectively. Moreover, the resistance of identified peptides to gastrointestinal degradation and their bitterness were predicted using in silico methods. PMID:26373334

  13. The value of combined strain gauge plethysmography and radioactive iodine fibrinogen scan of the leg in the diagnosis of deep vein thrombosis

    SciTech Connect

    AbuRahma, A.F.; Lawton, W.E. Jr.; Osborne, L.

    1983-05-01

    The fallibility of the clinical diagnosis of deep venous thrombosis has led to a variety of noninvasive diagnostic methods, for example, Doppler ultrasound, plethysmography, /sup 125/I fibrinogen and radionuclide phlebography. This study was undertaken to analyze the value of combined strain gauge plethysmography and /sup 125/I fibrinogen scan of the leg in the diagnosis of deep venous thrombosis. The study was carried out upon 368 patients with suggestive findings of venous thrombosis. Four hundred and fifty strain gauge plethysmograms were reviewed. Venograms were done upon 106 limbs and /sup 125/I fibrinogen leg scans, on 136 limbs. Of the 64 limbs with normal strain gauge plethysmograms which had venograms, 58 were normal, five had incompetent perforators and one limb had deep venous thrombosis. Of the 42 legs with abnormal strain gauge plethysmograms which had venograms, 25 had deep venous thrombosis, 15 had incompetent perforators and two were normal. Twenty-three of 24 legs having both abnormal strain gauge plethysmograms and leg scans were confirmed to have deep venous thrombosis at venography. Fourteen of 18 legs with abnormal strain gauge plethysmograms but normal scans were found to have incompetent perforators. We conclude, that the strain gauge plethysmogram is a reliable test in excluding deep venous thrombosis and, when combined with the fibrinogen leg scan, is reliable in its diagnosis.

  14. The lateral diffusion and fibrinogen induced clustering of platelet integrin αIIbβ3 reconstituted into physiologically mimetic GUVs.

    PubMed

    Gaul, Vinnie; Lopez, Sergio G; Lentz, Barry R; Moran, Niamh; Forster, Robert J; Keyes, Tia E

    2015-04-01

    Platelet integrin αIIbβ3 is a key mediator of platelet activation and thrombosis. Upon activation αIIbβ3 undergoes significant conformational rearrangement, inducing complex bidirectional signalling and protein recruitment leading to platelet activation. Reconstituted lipid models of the integrin can enhance our understanding of the structural and mechanistic details of αIIbβ3 behaviour away from the complexity of the platelet machinery. Here, a novel method of αIIbβ3 insertion into Giant Unilamellar Vesicles (GUVs) is described that allows for effective integrin reconstitution unrestricted by lipid composition. αIIbβ3 was inserted into two GUV lipid compositions that seek to better mimic the platelet membrane. First, "nature's own", comprising 32% DOPC, 25% DOPE, 20% CH, 15% SM and 8% DOPS, intended to mimic the platelet cell membrane. Fluorescence Lifetime Correlation Spectroscopy (FLCS) reveals that exposure of the integrin to the activators Mn(2+) or DTT does not influence the diffusion coefficient of αIIbβ3. Similarly, exposure to αIIbβ3's primary ligand fibrinogen (Fg) alone does not affect αIIbβ3's diffusion coefficient. However, addition of Fg with either activator reduces the integrin diffusion coefficient from 2.52 ± 0.29 to μm(2) s(-1) to 1.56 ± 0.26 (Mn(2+)) or 1.49 ± 0.41 μm(2) s(-1) (DTT) which is consistent with aggregation of activated αIIbβ3 induced by fibrinogen binding. The Multichannel Scaler (MCS) trace shows that the integrin-Fg complex diffuses through the confocal volume in clusters. Using the Saffman-Delbrück model as a first approximation, the diffusion coefficient of the complex suggests at least a 20-fold increase in the radius of membrane bound protein, consistent with integrin clustering. Second, αIIbβ3 was also reconstituted into a "raft forming" GUV with well defined liquid disordered (Ld) and liquid ordered (Lo) phases. Using confocal microscopy and lipid partitioning dyes, αIIbβ3 showed an affinity for

  15. Effect of Serum Fibrinogen, Total Stent Length, and Type of Acute Coronary Syndrome on 6-Month Major Adverse Cardiovascular Events and Bleeding After Percutaneous Coronary Intervention.

    PubMed

    Mahmud, Ehtisham; Ramsis, Mattheus; Behnamfar, Omid; Enright, Kelly; Huynh, Andrew; Kaushal, Khushboo; Palakodeti, Samhita; Li, Shiqian; Teh, Phildrich; Lin, Felice; Reeves, Ryan; Patel, Mitul; Ang, Lawrence

    2016-05-15

    This study evaluated the relation between baseline fibrinogen and 6-month major adverse cardiovascular events (MACE) and bleeding after percutaneous coronary intervention (PCI). Three hundred eighty-seven subjects (65.6 ± 16.1 years, 69.5% men, 26.9% acute coronary syndrome [ACS]) who underwent PCI with baseline fibrinogen and platelet reactivity (VerifyNow P2Y12 assay, Accumetrics, San Diego, California) measured were enrolled. Fibrinogen (368.8 ± 144.1 vs 316.8 ± 114.3 mg/dl; p = 0.001), total stent length (TSL; 44.5 ± 25.0 vs 32.2 ± 20.1 mm; p <0.001), and ACS presentation (40.6% vs 23.9%; p = 0.005) were independently associated with 6-month MACE rates (17.8%: myocardial infarction 9.8%, rehospitalization for ACS 3.6%, urgent revascularization 3.6%, stroke 0.5%, and death 0.3%). Measures of platelet reactivity were not associated with 6-month MACE. After multivariate analysis, fibrinogen ≥280 mg/dl (odds ratio [OR] 2.60, 95% CI 1.33 to 5.11, p = 0.005), TSL ≥32 mm (OR 3.21, 95% CI 1.82 to 5.64, p <0.001), and ACS presentation (OR 2.58, 95% CI 1.45 to 4.61, p = 0.001) were associated with higher 6-month MACE. In 271 subjects receiving chronic P2Y12 inhibitor therapy, 6-month Thrombolysis In Myocardial Infarction bleeding after PCI was 7.0%, but no difference in fibrinogen level (338.3 ± 109.7 vs 324.3 ± 113.8 mg/dl, p = 0.60) stratified by Thrombolysis In Myocardial Infarction bleeding was observed. In conclusion, elevated serum fibrinogen, ACS presentation, and longer TSL are independently associated with higher 6-month MACE after PCI, whereas no association with on-thienopyridine platelet reactivity and 6-month MACE was observed. Post-PCI bleeding was not associated with lower fibrinogen level. PMID:27040574

  16. Serum fibrin(ogen) degradation products in diagnosis of deep-vein thrombosis and pulmonary embolism after hip surgery.

    PubMed

    Cooke, E D; Bowcock, S A; Pilcher, M F; Ibbotson, R M; Gordon, Y B; Sola, C M; Chard, T; Ainsworth, M E

    1975-07-12

    Levels of fibrin(ogen) degradation products (F.D.P.) have been measured by radioimmunoassay for degradation product E (FgE) and by tanned-red-cell haemagglutination-inhibition immunoassay (T.R.C.H.I.I.) in the serum of thirty-three patients undergoing total hip replacement. Levels of F.D.P. did not correlate with thermographic evidence of deep-venous thrombosis. However, in 34 patients with pulmonary embolism, levels of F.D.P. measured by the T.R.C.H.I.I. were transiently raised at the time of embolus, and FgE concentrations were increased for up to 5 days preceding the embolus. Since the measurments of FgE is simple, convenient, and cheap, this estimation might constitute a valuable screening test for major thromboembolic episodes in the postoperative period. PMID:49650

  17. Familial mutations in fibrinogen Aα (FGA) chain identified in renal amyloidosis increase in vitro amyloidogenicity of FGA fragment.

    PubMed

    Sivalingam, Vishwanath; Patel, Basant K

    2016-08-01

    Amyloidoses are clinical disorders where deposition of β-sheet rich, misfolded protein aggregates called amyloid occurs in vital organs like brain, kidney, liver or heart etc. Aggregation of several proteins such as immunoglobulin light chain, fibrinogen Aα chain (FGA) and lysozyme have been found to be associated with renal amyloidosis. Fibrinogen amyloidosis (AFib) is predominantly familial and is associated with the deposition of mutant FGA amyloid, primarily in kidneys. Over ten substitution and frame-shift mutations in FGA have been identified from AFib patients. Whether wild-type FGA is also involved in AFib is yet unknown. The affected tissues from AFib patients usually show ∼10 kDA peptide from C-terminal 80 amino acid residues of mutant FGA. Notably, this region also encompasses all known disease-related mutations. Whether these point mutations increase the amyloidogenicity of FGA leading to disease progression, have not been studied yet. Here, we have investigated the role of two disease-related mutations in affecting amyloidogenic propensity of an FGA(496-581) fragment. We found that at physiological pH, the wild-type FGA(496-581) fragment remains monomeric, whereas its E540V mutant forms amyloid-like fibrils as observed by AFM. Also, FGA(496-581) harbouring another familial mutation, R554L, converts in vitro into globular, β-sheet rich aggregates, showing amyloid-like properties. These findings suggest that familial mutations in FGA may have role in renal amyloidosis via enhanced amyloid formation. PMID:27126074

  18. Equilibrium binding of thrombin to recombinant human thrombomodulin: Effect of hirudin, fibrinogen, factor Va, and peptide analogues

    SciTech Connect

    Tsiang, Manuel; Lentz, S.R.; Dittman, W.A.; Wen, D.; Scarpati, E.M.; Sadler, J.E. )

    1990-11-01

    Thrombomodulin is an endothelial cell surface receptor for thrombin that acts as a physiological anticoagulant. The properties of recombinant human thrombomodulin were studied in COS-7, CHO, CV-1, and K562 cell lines. Thrombomudlin was expressed on the cell surface as shown by the acquisition of thrombin-dependent protein C activation. Like native thrombomodulin, recombinant thrombomodulin contained N-linked oligosaccharides, had M{sub r} {approximately} 100 000, and was inhibited or immunoprecipitated by anti-thrombomodulin antibodies. Binding studies demonstrated that nonrecombinant thrombomodulin expressed by A549 carcinoma cells and recombinant thrombomodulin expressed by CV-1 and K562 cells had similar K{sub d}'s for thrombin of 1.3 nM, 3.3 nM, and 4.7 nM, respectively. The K{sub d} for DIP-thrombin binding to recombinant thrombomodulin on CV-1(18A) cells was identical with that of thrombin. Increasing concentrations of hirudin or fibrinogen progressively inhibited the binding of {sup 125}I-DIP-thrombin, while factor Va did not inhibit binding. Three synthetic peptides were tested for ability to inhibit DIP-thrombin, while factor Va did not inhibit binding. Three synthetic peptides were tested for ability to inhibit DIP-thrombin binding. Both the hirudin peptide Hir{sup 53-64} and the thrombomodulin fifth-EGF-domain peptide Tm{sup 426-444} displaced DIP-thrombin from thrombomodulin, but the factor V peptide FacV{sup 30-43} which is similar in composition and charge to Hir{sup 53-64} showed no binding inhibition. The data exclude the significant formation of a ternary complex consisting of thrombin, thrombomodulin, and hirudin. These studies are consistent with a model in which thrombomodulin, hirudin, and fibrinogen compete for binding to DIP-thrombin at the same site.

  19. Ranking reactive glutamines in the fibrinogen αC region that are targeted by blood coagulant factor XIII.

    PubMed

    Mouapi, Kelly Njine; Bell, Jacob D; Smith, Kerrie A; Ariëns, Robert A S; Philippou, Helen; Maurer, Muriel C

    2016-05-01

    Factor XIIIa (FXIIIa) introduces covalent γ-glutamyl-ε-lysyl crosslinks into the blood clot network. These crosslinks involve both the γ and α chains of fibrin. The C-terminal portion of the fibrin α chain extends into the αC region (210-610). Crosslinks within this region help generate a stiffer clot, which is more resistant to fibrinolysis. Fibrinogen αC (233-425) contains a binding site for FXIIIa and three glutamines Q237, Q328, and Q366 that each participate in physiological crosslinking reactions. Although these glutamines were previously identified, their reactivities toward FXIIIa have not been ranked. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and nuclear magnetic resonance (NMR) methods were thus used to directly characterize these three glutamines and probe for sources of FXIIIa substrate specificity. Glycine ethyl ester (GEE) and ammonium chloride served as replacements for lysine. Mass spectrometry and 2D heteronuclear single quantum coherence NMR revealed that Q237 is rapidly crosslinked first by FXIIIa followed by Q366 and Q328. Both (15)NH4Cl and (15)N-GEE could be crosslinked to the three glutamines in αC (233-425) with a similar order of reactivity as observed with the MALDI-TOF mass spectrometry assay. NMR studies using the single αC mutants Q237N, Q328N, and Q366N demonstrated that no glutamine is dependent on another to react first in the series. Moreover, the remaining two glutamines of each mutant were both still reactive. Further characterization of Q237, Q328, and Q366 is important because they are located in a fibrinogen region susceptible to physiological truncations and mutation. The current results suggest that these glutamines play distinct roles in fibrin crosslinking and clot architecture. PMID:26951791

  20. Antithrombin III and fibrinogen degradation product (fragment E) in diabetic nephropathy.

    PubMed

    Chan, V; Yeung, C K; Chan, T K

    1982-06-01

    Plasma antithrombin III (AtIII), serum fragment E (FgE) and urine AtIII and FgE were measured in 25 diabetic patients with proteinuria above 1 g per day and compared to that in 25 patients with non-diabetic nephropathy, matched for the degree of proteinuria. Plasma AtIII concentrations were normal in both groups but FgE concentrations were increased. The level of plasma AtIII was directly related to HbA1 concentrations in the diabetics. For the same degree of proteinuria, the diabetic patients lost more AtIII and FgE in the urine. Urine AtIII was found to be mostly bound to activated procoagulants. Both urine AtIII and urine FgE correlated inversely with creatinine clearance. It was concluded that intraglomerular thrombosis probably contributes to the deteriorating renal function in diabetic nephropathy and is reflected in the concentrations of urine AtIII and FgE. PMID:7085916

  1. Antithrombin III and fibrinogen degradation product (fragment E) in diabetic nephropathy.

    PubMed Central

    Chan, V; Yeung, C K; Chan, T K

    1982-01-01

    Plasma antithrombin III (AtIII), serum fragment E (FgE) and urine AtIII and FgE were measured in 25 diabetic patients with proteinuria above 1 g per day and compared to that in 25 patients with non-diabetic nephropathy, matched for the degree of proteinuria. Plasma AtIII concentrations were normal in both groups but FgE concentrations were increased. The level of plasma AtIII was directly related to HbA1 concentrations in the diabetics. For the same degree of proteinuria, the diabetic patients lost more AtIII and FgE in the urine. Urine AtIII was found to be mostly bound to activated procoagulants. Both urine AtIII and urine FgE correlated inversely with creatinine clearance. It was concluded that intraglomerular thrombosis probably contributes to the deteriorating renal function in diabetic nephropathy and is reflected in the concentrations of urine AtIII and FgE. Images PMID:7085916

  2. Plasmin cleaves fibrinogen and the human complement proteins C3b and C5 in the presence of Leptospira interrogans proteins: A new role of LigA and LigB in invasion and complement immune evasion.

    PubMed

    Castiblanco-Valencia, Mónica Marcela; Fraga, Tatiana Rodrigues; Pagotto, Ana Helena; Serrano, Solange Maria de Toledo; Abreu, Patricia Antonia Estima; Barbosa, Angela Silva; Isaac, Lourdes

    2016-05-01

    Plasminogen is a single-chain glycoprotein found in human plasma as the inactive precursor of plasmin. When converted to proteolytically active plasmin, plasmin(ogen) regulates both complement and coagulation cascades, thus representing an important target for pathogenic microorganisms. Leptospira interrogans binds plasminogen, which is converted to active plasmin. Leptospiral immunoglobulin-like (Lig) proteins are surface exposed molecules that interact with extracellular matrix components and complement regulators, including proteins of the FH family and C4BP. In this work, we demonstrate that these multifunctional molecules also bind plasminogen through both N- and C-terminal domains. These interactions are dependent on lysine residues and are affected by ionic strength. Competition assays suggest that plasminogen does not share binding sites with C4BP or FH on Lig proteins at physiological molar ratios. Plasminogen bound to Lig proteins is converted to proteolytic active plasmin in the presence of urokinase-type plasminogen activator (uPA). Lig-bound plasmin is able to cleave the physiological substrates fibrinogen and the complement proteins C3b and C5. Taken together, our data point to a new role of LigA and LigB in leptospiral invasion and complement immune evasion. Plasmin(ogen) acquisition by these versatile proteins may contribute to Leptospira infection, favoring bacterial survival and dissemination inside the host. PMID:26822552

  3. Effects of infection on plasma levels of copper and zinc in ewes.

    PubMed

    Lamand, M; Levieux, D

    1981-01-01

    Plasma copper and zinc in 20 ewes, healthy or infected with chronic postpartum metritis or mastitis, have been determined by atomic absorption spectrophotometry. Plasma protein profile was measured by electrophoresis on cellulose acetate plates, and albumin and ceruloplasmin were determined colorimetrically. For the ten initial days, plasma copper and ceruloplasmin increased in plasma zinc decreased in spite of a daily drenching of 200 mg Zn/ewe (as sulfate). Fibrinogen and IgG2 increased and albumin decreased slightly indicating an infectious process. After a five day period of intramuscular injection with chloramphenicol, tetracycline and prednisolone, plasma zinc increased but copper remained unchanged. It may be concluded that hypozincemia should not be attributed to a zinc deficiency without any information on biochemical parameters specific for inflammation of infection. An inflammatory hypozincemia is not affected by a zinc treatment even at a high level. PMID:7200753

  4. Fibulin-1 purification from human plasma using affinity chromatography on Factor H-Sepharose.

    PubMed

    DiScipio, Richard G; Liddington, Robert C; Schraufstatter, Ingrid U

    2016-05-01

    A method is reported to purify Fibulin-1 from human plasma resulting in a 36% recovery. The steps involve removal of the cryoglobulin and the vitamin K dependent proteins followed by polyethylene glycol and ammonium sulfate precipitations, DEAE-Sephadex column chromatography and finally Factor H-Sepharose affinity purification. The procedure is designed to be integrated into an overall scheme for the isolation of over 30 plasma proteins from a single batch of human plasma. Results from mass spectroscopy, SDS-PAGE, and Western blotting indicate that human plasma Fibulin-1 is a single chain of the largest isotype. Functional binding assays demonstrated calcium ion dependent interaction of Fibulin-1 for fibrinogen, fibronectin, and Factor H. The procedure described is the first to our knowledge that enables a large scale purification of Fibulin-1 from human plasma. PMID:26826315

  5. Impact of Transcendental Meditation® on cardiovascular function at rest and during acute stress in adolescents with high normal blood pressure

    PubMed Central

    Barnes, Vernon A.; Treiber, Frank A.; Davis, Harry

    2011-01-01

    Objective This study examined the impact of the Transcendental Meditation (TM) program on cardiovascular (CV) reactivity in adolescents with high normal blood pressure (BP). Method Thirty-five adolescents [34 African Americans (AAs), 1 Caucasian American (CA); ages 15–18 years] with resting systolic blood pressure (SBP) between the 85th and 95th percentile for their age and gender on three consecutive occasions, were randomly assigned to either TM (n = 17) or health education control (CTL, n = 18) groups. The TM group engaged in 15-min meditation twice each day for 2 months including sessions during school lunch break. Primary CV outcome measures were changes in BP, heart rate (HR), and cardiac output (CO) at rest and in response to two laboratory stressors, a simulated car driving stressor and an interpersonal social stressor interview. Results The TM group exhibited greater decreases in resting SBP (P < .03) from pre- to post-intervention, compared to the CTL group. The TM group exhibited greater decreases from pre- to postintervention in SBP, HR, and CO reactivity (P’s < .03) to the simulated car driving stressor, and in SBP reactivity (P < .03) to the social stressor interview. Conclusion The TM program appears to have a beneficial impact upon CV functioning at rest and during acute laboratory stress in adolescents at-risk for hypertension. PMID:11595248

  6. In vivo effects and interactions of recombinant interleukin 1 and tumor-necrosis factor in radioprotection and induction of fibrinogen. Scientific report

    SciTech Connect

    Neta, R.

    1988-01-01

    Although interleukin 1 (IL-1) and tumor necrosis factor (TNF) are both produced by stimulated macrophage-monocytes, they are molecularly distinct, act via separate receptors, but show striking resemblance in their biological activity. Both cytokines are pyrogenic, induce colony-stimulating factor and acute-phase proteins, activate neutrophils, reduce cytochrome P-450 functions, and inhibit lipoprotein lipase. Furthermore, IL-1 and TNF have been reported to induce the release of one another. Because of this mutual induction, the relative contribution of IL-1 or TNF to the induction of a given activity becomes difficult to establish. In an attempt to determine whether these two cytokines act independently, the effect of administrating them separately or in combination is compared on the radioprotection and on the induction of an acute-phase reactant - fibrinogen. IL-1 and TNF have synergistic effects on radioprotection and on the levels of circulating fibrinogen.

  7. A hemocyte-expressed fibrinogen-related protein gene (LvFrep) from the shrimp Litopenaeus vannamei: Expression analysis after microbial infection and during larval development.

    PubMed

    Coelho, Jaqueline da Rosa; Barreto, Cairé; Silveira, Amanda da Silva; Vieira, Graziela Cleusa; Rosa, Rafael Diego; Perazzolo, Luciane Maria

    2016-09-01

    Fibrinogen-related proteins (FREPs) comprise a large family of microbial recognition proteins involved in many biological functions in both vertebrate and invertebrate animals. By taking advantage of publicly accessible databases, we have identified a FREP-like homolog in the most cultivated penaeid shrimp, Litopenaeus vannamei (LvFrep). The obtained sequence showed a conserved fibrinogen-related domain (FReD) and displayed significant similarities to FREP-like proteins from other invertebrates and to ficolins from crustaceans. The expression of LvFrep appeared to be limited to circulating hemocytes. Interestingly, LvFrep gene expression was induced in shrimp hemocytes only in response to a Vibrio infection but not to the White spot syndrome virus (WSSV). Moreover, LvFrep transcript levels were detected early in fertilized eggs, suggesting the participation of this immune-related gene in the antimicrobial defenses during shrimp development. PMID:27380968

  8. The influence of riboflavin photochemistry on plasma coagulation factors

    PubMed Central

    Larrea, Luis; Calabuig, María; Roldán, Vanesa; Rivera, José; Tsai, Han-Mou; Vicente, Vicente; Roig, Roberto

    2011-01-01

    Studies with riboflavin in the 1960s showed that it could be effective at inactivating pathogens when exposed to light. The principal mode of action is through electron transfer reactions, most importantly in nucleic acids. This suggested that it could act as a photosensitizer useful in the inactivation of pathogens found in blood products. Objective To study the influence of photo-inactivation with riboflavin on the coagulation factors of plasma. Methods The photo-inactivation procedure of riboflavin plus light was applied. Fifty isogroup pools of two plasmas were made from 100 U of plasma that were derived from whole blood products that had previously been held overnight. Pools were split into two bags. One of them was photo-inactivated, and post inactivation samples were obtained. The second bag was not photo-inactivated and samples were taken. Total protein, fibrinogen, FII, FV, FVII, FVIII, FIX, FX, FXI, FXIII, antithrombin III, PC, PS, α-2 antiplasmin and vWF:Ag, the multimeric structure of vWF and ADAMTS-13 were analyzed. Results In plasma, the proteins most sensitive to photo-inactivation were fibrinogen, FXI, FVIII, FV, and FIX (33%, 32%, 30%, 18% and 18% loss, respectively). Coagulation inhibitors, PS, antithrombin III and PC showed little decrease (all 2%). Retention of vWF and ADAMTS-13 were 99% and 88%, respectively. Conclusions As with other pathogen reduction procedures for plasma products, treatment with riboflavin and UV light resulted in reduction in the activity levels of several pro-coagulant factors. Coagulation inhibitors are well preserved. PMID:19782644

  9. Plasma turbulence

    SciTech Connect

    Horton, W.; Hu, G.

    1998-07-01

    The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates.

  10. Effects on fibrinogen, fibrin, and blood coagulation of proteolytic extracts from fruits of Pseudananas macrodontes, Bromelia balansae, and B. hieronymi (Bromeliaceae) in comparison with bromelain.

    PubMed

    Errasti, María E; Prospitti, Anabela; Viana, Carolina A; Gonzalez, Mariana M; Ramos, Márcio V; Rotelli, Alejandra E; Caffini, Néstor O

    2016-06-01

    Extracts rich in cysteine proteases obtained from fruits of Pseudananas macrodontes (Pm), Bromelia balansae (Bb), and B. hieronymi (Bh) have previously shown an anti-inflammatory effect on animal models. Given the close relationship between hemostasis and inflammation, it is attractive to investigate therapeutic agents capable of modulating both systems. The aim of this work was to study the effect of Pm, Bb, and Bh on fibrin(ogen) and blood coagulation compared with stem bromelain (Bro). Action on fibrinogen was electrophoretically and spectrophotometrically evaluated, fibrinolytic activity was measured both electrophoretically and by the fibrin plate assay, and the effect on blood coagulation was studied by conventional coagulation tests (PT and APPT). All extracts showed the same proteolytic preference for fibrinogen subunits, that is Aα > Bβ, whereas γ was partially hydrolyzed by 100-fold concentration increase. Unlike Bro, cysteine proteases of Pm, Bb, and Bh increased absorbance at 540 nm of fibrinogen solution, suggesting thrombin-like activity, which was time-dependent and reached maximum values at lower concentration. All extracts showed the same proteolytic preference for fibrin subunits; however Pm, Bb, and Bh showed lower fibrinolytic activity than Bro at the assayed concentrations. Although Bb acted only as anticoagulant, Pm, Bh, and unexpectedly Bro showed dual action on blood coagulation: at low concentration showed procoagulant effect and at high concentration anticoagulant effect. Results reveal new plant species as potential sources of pharmacological agents for the treatment of a wide range of hemostatic disorders as well as to wound healing. PMID:26886361

  11. Differences between neonates and adults in tissue-type-plasminogen activator (t-PA)-catalyzed plasminogen activation with various effectors and in carbohydrate sequences of fibrinogen chains.

    PubMed

    Ries, M; Easton, R L; Longstaff, C; Zenker, M; Corran, P H; Morris, H R; Dell, A; Gaffney, P J

    2001-08-01

    Our study investigates the effect of fetal and adult soluble fibrin (SF), fetal and adult fibrinogen Aalpha- and gamma-chains, as well as adult CNBr-fibrinogen fragments on tissue-type plasminogen activator (t-PA)-catalyzed plasminogen activation of both fetal and adult Glu-plasminogen types 1 and 2. In addition, we determined carbohydrate sequences of fetal and adult Bbeta- and gamma-chains by mass spectrometric analysis. In the absence of an effector, no substantial differences in the rate of plasmin formation could be seen between the fetal and adult plasminogen types. In the presence of an effector, both fetal Glu-plasminogen types revealed lower values for k(cat app) than the respective adult types. No differences could be seen in the values for K(m app). The resulting differences in catalytic efficiencies between the fetal and adult plasminogen types were much less than previously reported. No differences could be seen between fetal and adult effectors in stimulating t-PA-catalyzed plasminogen activation. Detailed analyses of the activation kinetics revealed a longer initial phase of slow plasmin formation of both fetal Glu-plasminogen types compared to their respective adult types, indicating a slower plasmin-induced modification of CNBr-fibrinogen fragments or SF by fetal plasmin. Mass spectrometric analysis of the N-glycans present on adult and fetal Bbeta- and gamma-fibrinogen chains showed the presence of a major monosialylated biantennary structure with lesser amounts of the disialylated form. In contrast to previous data, we conclude that catalytic efficiency of t-PA-catalyzed plasminogen activation in neonates is only slightly lower than in adults. PMID:11672579

  12. Fibrinogen-Related Proteins in Tissue Repair: How a Unique Domain with a Common Structure Controls Diverse Aspects of Wound Healing

    PubMed Central

    Zuliani-Alvarez, Lorena; Midwood, Kim S.

    2015-01-01

    Significance: Fibrinogen-related proteins (FRePs) comprise an intriguing collection of extracellular molecules, each containing a conserved fibrinogen-like globe (FBG). This group includes the eponymous fibrinogen as well as the tenascin, angiopoietin, and ficolin families. Many of these proteins are upregulated during tissue repair and exhibit diverse roles during wound healing. Recent Advances: An increasing body of evidence highlights the specific expression of a number of FRePs following tissue injury and infection. Upon induction, each FReP uses its FBG domain to mediate quite distinct effects that contribute to different stages of tissue repair, such as driving coagulation, pathogen detection, inflammation, angiogenesis, and tissue remodeling. Critical Issues: Despite a high degree of homology among FRePs, each contains unique sequences that enable their diversification of function. Comparative analysis of the structure and function of FRePs and precise mapping of regions that interact with a variety of ligands has started to reveal the underlying molecular mechanisms by which these proteins play very different roles using their common domain. Future Directions: Fibrinogen has long been used in the clinic as a synthetic matrix serving as a scaffold or a delivery system to aid tissue repair. Novel therapeutic strategies are now emerging that harness the use of other FRePs to improve wound healing outcomes. As we learn more about the underlying mechanisms by which each FReP contributes to the repair response, specific blockade, or indeed potentiation, of their function offers real potential to enable regulation of distinct processes during pathological wound healing. PMID:26005593

  13. 1H NMR sequential assignments and secondary structure analysis of human fibrinogen gamma-chain C-terminal residues 385-411

    SciTech Connect

    Mayo, K.H.; Burke, C.; Lindon, J.N.; Kloczewiak, M. )

    1990-04-03

    The human fibrinogen gamma-chain, C-terminal fragment, residues 385-411, i.e., KIIPFNRLTIGEGQQHHLGGAKQAGDV, contains two biologically important functional domains: (1) fibrinogen gamma-chain polymerization center and (2) platelet receptor recognition domain. This peptide was isolated from cyanogen bromide degraded human fibrinogen and was investigated by 1H NMR (500 MHz) spectroscopy. Sequence-specific assignments of NMR resonances were obtained for backbone and side-chain protons via analysis of 2D NMR COSY, double quantum filtered COSY, HOHAHA, and NOESY spectra. The N-terminal segment from residues 385-403 seems to adopt a relatively fixed solution conformation. Strong sequential alpha CH-NH NOESY connectivities and a continuous run of NH-NH NOESY connectivities and several long-lived backbone NH protons strongly suggest the presence of multiple-turn or helix-like structure for residues 390 to about 402. The conformation of residues 403-411 seems to be much less constrained as evidenced by the presence of weaker and sequential alpha CH-NH NOEs, the absence of sequential NH-NH NOEs, and the lack of longer lived amides. Chemical shifts of resonances from backbone and side-chain protons of the C-terminal dodecapeptide, residues 400-411, differ significantly from those of the parent chain, suggesting that some preferred C-terminal conformation does exist.

  14. M1 macrophage infiltrations and histological changes in the liver after portal vein embolization using fibrinogen and OK432 in the rat.

    PubMed

    Sato, Tetsu; Marubashi, Shigeru; Kenjo, Akira; Tsuchiya, Takao; Kimura, Takashi; Sato, Naoya; Watanabe, Junichiro; Tasaki, Kazuhiro; Hashimoto, Yuko; Wada, Ikuo; Gotoh, Mitsukazu

    2016-05-01

    The mechanism of anti-tumor effect of transarterial Immuno-Embolization (TIE) using OK-432 has not been well elucidated. In this study, we aimed to investigate the tissue injury and immune response after portal venous embolization (PVE) with/without OK-432. Embolic materials (L group: lipiodol, LF group: lipiodol+fibrinogen, LO group: lipiodol+OK-432, LFO group: lipiodol+fibrinogen+OK-432) were administered via the right portal vein in Wistar rats. The histological findings in LFO group demonstrated liver damage with severe architectural changes. The concentrations of CD68(+) cells were observed in a time-dependent manner; it was significantly increased in the LO group on day 1 and in the LFO group on day 3. CD68(+)CD163(-) macrophages significantly increased in the LFO group on day 7 (P<0.05). In conclusion, PVE with fibrinogen and OK-432 markedly increased the CD68(+)CD163(-) infiltrating macrophages around the peri-portal area in the liver. This novel technique could be applied as immune-enhanced chemo-embolization of liver tumors. PMID:27062693

  15. Ligands to the platelet fibrinogen receptor glycoprotein IIb-IIIa do not affect agonist-induced second messengers Ca2+ or cyclic AMP.

    PubMed Central

    Williams, J A; Ashby, B; Daniel, J L

    1990-01-01

    Previous studies have suggested that the platelet glycoprotein complex GPIIb-IIIa, which is the putative fibrinogen receptor, regulates Ca2+ influx into platelets, possibly operating as a Ca2+ channel. We have used RGD-peptides (peptides containing the sequence Arg-Gly-Asp; disintegrins), isolated from snake venoms, that have a high affinity and specificity for the fibrinogen-binding site of GPIIb-IIIa to address the question of whether blocking this site inhibits Ca2+ movement from the extracellular medium to the cytosol. Using fura-2-loaded human platelets, we found that neither disintegrins nor a monoclonal antibody (M148) to the GPIIb-IIIa complex altered the level of cytosolic Ca2+ obtained when the cells were stimulated with various agonists in the presence of either nominal or 1 mM extracellular Ca2+. In the presence of Mn2+, an ion that quenches fura-2 fluorescence, fura-2-loaded platelets were stimulated with thrombin or ADP. Neither disintegrins nor the monoclonal antibody altered the kinetics or the amount of quenching of fura-2 fluorescence by Mn2+. These data indicate that the binding of ligands to the fibrinogen receptor is not associated with an inhibition of Ca2+ movement through a receptor-operated channel. Furthermore, the disintegrins have no effect on platelet cyclic AMP metabolism in either the presence or the absence of phosphodiesterase inhibitors. PMID:2168700

  16. Influence of high-normal serum TSH levels on major cardiovascular risk factors and Visceral Adiposity Index in euthyroid type 2 diabetic subjects.

    PubMed

    Giandalia, A; Russo, G T; Romeo, E L; Alibrandi, A; Villari, P; Mirto, A A; Armentano, G; Benvenga, S; Cucinotta, D

    2014-09-01

    Although several observations indicate that serum TSH levels in the high normal range are related to cardiovascular (CVD) risk factors in the general population, similar data are limited in diabetic subjects. The aim of this study was to investigate the potential associations between TSH serum levels within the normal range and major metabolic and non-metabolic CVD risk factors in a cohort of euthyroid type 2 diabetic subjects. Thyroid hormones, TSH levels, anthropometric parameters, lipid profile, glucose control, and blood pressure were measured in 490 euthyroid type 2 diabetic subjects, consecutively attending two outpatient diabetic units in Southern Italy. In all subjects, we also calculated the Visceral Adiposity Index (VAI), an obesity-related index associated with CVD risk. Diabetic women showed higher mean serum TSH levels and lower FT4 concentration than diabetic men, while FT3 levels were comparable in the two genders. Stratifying the study population according to quartiles of TSH levels, subjects in the highest TSH quartile were more likely to be female and younger, with higher values of BMI and waist circumference (P = 0.05 both), higher triglycerides (P = 0.002) and non-HDL cholesterol concentrations (P = 0.01), higher VAI values (P = 0.02), and lower FT4 levels (P = 0.05), when compared to those in the lowest quartile. At multivariate analysis, a younger age, female gender, triglycerides levels, and waist circumference were independently associated with higher TSH levels. In conclusion, in type 2 diabetic subjects with no evidence of thyroid disease, higher TSH concentrations within the normal range were more frequent in women and in younger subjects, and they were associated with visceral obesity and higher triglycerides concentrations, two well-known CVD risk factors. PMID:24385267

  17. Ancrod revisited: viscoelastic analyses of the effects of Calloselasma rhodostoma venom on plasma coagulation and fibrinolysis.

    PubMed

    Nielsen, Vance G

    2016-08-01

    Fibrinogen depletion via catalysis by snake venom enzymes as a therapeutic strategy to prevent or treat thrombotic disorders was utilized for over four decades, with ancrod being the quintessential agent. However, ancrod eventually was found to not be of clinical utility in large scale stroke trial, resulting in the eventual discontinuation of the administration of the drug for any indication. It was hypothesized that ancrod, possessing thrombin-like activity, may have unappreciated robust coagulation kinetics. Using thrombelastographic methods, a comparison of equivalent tissue factor initiated thrombin generation and Calloselasma rhodostoma venom (rich in ancrod activity) on plasmatic coagulation kinetics was performed. The venom resulted in thrombi that formed nearly twice as fast compared to thrombin formed clots, and there was no difference in fibrinolytic kinetics initiated by tissue-type plasminogen activator. In plasma containing iron and carbon monoxide modified fibrinogen, which may be found in patients at risk of stroke, the coagulation kinetic differences observed with venom was still more vigorous than that seen with thrombin. These phenomena may provide insight into the clinical failure of ancrod, and may serve as an impetus to revisit the concept of fibrinogen depletion via fibrinogenolytic enzymes, not those with thrombin-like activity. PMID:26905070

  18. Plasma protein induced clustering of red blood cells in micro capillaries

    NASA Astrophysics Data System (ADS)

    Wagner, Christian; Brust, Mathias; Aouane, Othmane; Flormann, Daniel; Thiebaud, Marine; Verdier, Claude; Coupier, Gwennou; Podgorski, Thomas; Misbah, Chaouqi; Selmi, Hassib

    2013-11-01

    The plasma molecule fibrinogen induces aggregation of RBCs to clusters, the so called rouleaux. Higher shear rates in bulk flow can break them up which results in the pronounced shear thinning of blood. This led to the assumption that rouleaux formation does not take place in the microcapillaries of the vascular network where high shear rates are present. However, the question is of high medical relevance. Cardio vascular disorders are still the main cause of death in the western world and cardiac patients have often higher fibrinogen level. We performed AFM based single cell force spectroscopy to determine the work of separation. Measurements at low hematocrit in a microfluidic channel show that the number of size of clusters is determined by the adhesion strength and we found that cluster formation is strongly enhanced by fibrinogen at physiological concentrations, even at shear rate as high as 1000 1/s. Numerical simulations based on a boundary integral method confirm our findings and the clustering transition takes place both in the experiments and in the simulations at the same interaction energies. In vivo measurements with intravital fluorescence microscopy in a dorsal skin fold chamber in a mouse reveal that RBCs indeed form clusters in the micrcapillary flow. This work was supported by the German Science Foundation research imitative SFB1027.

  19. Immunoconglutinin and antibody against fibrinogen products in hemolytic anemia and nephritis resulting from infection with a Haemobartonella-like agent.

    PubMed

    Thoongsuwan, S; Cox, H W

    1981-08-01

    An agent morphologically similar to Haemobartonella muris was isolated from the blood of rats infected with a strain of Trypanosoma lewisi kept at this Department. It caused acute hemolytic anemia, splenomegaly, glomerulonephritis, and death within 5 to 8 days in mature Sprague-Dawley rats. The disease was less severe in weanling rats which usually recovered within 3 to 4 wk. The anemia was accompanied by phagocytosis of erythrocytes by monocytes of the spleen and bone marrow, by high titers of cold-active hemagglutinin, high titers of antibody to the third component of fixed complement (immunoconglutinin), and antibody to fibrinogen/fibrin related products. Filtrates of blood from anemic rats passing a 0.20-micron filter did not produce disease or signs of infections, but filtrate from a 0.45-micron filter was infective. Attempts to grow the agent on rat embryo fibroblast cultures and in embryonated chicken eggs were successful. Tests for bacteria, mycoplasma, and spirochetes gave negative results. Blood of infected rats did not produce signs of infections when inoculated into laboratory mice, and normal rats housed in cages with acutely infected rats did not develop signs of infection or disease. Morphological similarity did not allow differentiation of the agent from H. muris. However, its virulence for mature rats differs markedly from that usually seen in H. muris infection. PMID:7264835

  20. Ablation of MMP9 gene ameliorates paracellular permeability and fibrinogen-amyloid beta complex formation during hyperhomocysteinemia.

    PubMed

    Muradashvili, Nino; Tyagi, Reeta; Metreveli, Naira; Tyagi, Suresh C; Lominadze, David

    2014-09-01

    Increased blood level of homocysteine (Hcy), called hyperhomocysteinemia (HHcy) accompanies many cognitive disorders including Alzheimer's disease. We hypothesized that HHcy-enhanced cerebrovascular permeability occurs via activation of matrix metalloproteinase-9 (MMP9) and leads to an increased formation of fibrinogen-β-amyloid (Fg-Aβ) complex. Cerebrovascular permeability changes were assessed in C57BL/6J (wild type, WT), cystathionine-β-synthase heterozygote (Cbs+/-, a genetic model of HHcy), MMP9 gene knockout (Mmp9-/-), and Cbs and Mmp9 double knockout (Cbs+/-/Mmp9-/-) mice using a dual-tracer probing method. Expression of vascular endothelial cadherin (VE-cadherin) and Fg-Aβ complex formation was assessed in mouse brain cryosections by immunohistochemistry. Short-term memory of mice was assessed with a novel object recognition test. The cerebrovascular permeability in Cbs+/- mice was increased via mainly the paracellular transport pathway. VE-cadherin expression was the lowest and Fg-Aβ complex formation was the highest along with the diminished short-term memory in Cbs+/- mice. These effects of HHcy were ameliorated in Cbs+/-/Mmp9-/- mice. Thus, HHcy causes activation of MMP9 increasing cerebrovascular permeability by downregulation of VE-cadherin resulting in an enhanced formation of Fg-Aβ complex that can be associated with loss of memory. These data may lead to the identification of new targets for therapeutic intervention that can modulate HHcy-induced cerebrovascular permeability and resultant pathologies. PMID:24865997

  1. Using Neutron Reflectometry to Discern the Structure of Fibrinogen Adsorption at the Stainless Steel/Aqueous Interface.

    PubMed

    Wood, Mary H; Browning, Kathryn L; Barker, Robert D; Clarke, Stuart M

    2016-06-23

    Neutron reflectometry has been successfully used to study adsorption on a stainless steel surface by means of depositing a thin steel film on silicon. The film was characterized using XPS (X-ray photoelectron spectroscopy), TOF-SIMS (time-of-flight secondary ion mass spectrometry), and GIXRD (grazing incidence X-ray diffraction), demonstrating the retention both of the austenitic phase and of the required composition for 316L stainless steel. The adsorption of fibrinogen from a physiologically-relevant solution onto the steel surface was studied using neutron reflectometry and QCM (quartz crystal microbalance) and compared to that on a deposited chromium oxide surface. It was found that the protein forms an irreversibly bound layer at low concentrations, with maximum protein concentration a distance of around 20 Å from the surface. Evidence for a further diffuse reversibly-bound layer forming at higher concentrations was also observed. Both the structure of the layer revealed by the neutron reflectometry data and the high water retention predicted by the QCM data suggest that there is a significant extent of protein unfolding upon adsorption. A lower extent of adsorption was seen on the chromium surfaces, although the adsorbed layer structures were similar, suggesting comparable adsorption mechanisms. PMID:27244444

  2. Overexpression of Fibrinogen-Like Protein 2 Promotes Tolerance in a Fully Mismatched Murine Model of Heart Transplantation.

    PubMed

    Bartczak, A; Chruscinski, A; Mendicino, M; Liu, H; Zhang, J; He, W; Amir, A Z; Nguyen, A; Khattar, R; Sadozai, H; Lobe, C G; Adeyi, O; Phillips, M J; Zhang, L; Gorczynski, R M; Grant, D; Levy, G A

    2016-06-01

    Fibrinogen-like protein 2 (FGL2) is an immunomodulatory protein that is expressed by regulatory T cells (Tregs). The objective of this study was to determine if recombinant FGL2 (rFGL2) treatment or constitutive FGL2 overexpression could promote transplant tolerance in mice. Although rFGL2 treatment prevented rejection of fully mismatched cardiac allografts, all grafts were rejected after stopping treatment. Next, we generated FGL2 transgenic mice (fgl2(Tg) ) that ubiquitously overexpressed FGL2. These mice developed normally and had no evidence of the autoimmune glomerulonephritis seen in fgl2(-/-) mice. Immune characterization showed fgl2(Tg) T cells were hypoproliferative to stimulation with alloantigens or anti-CD3 and anti-CD28 stimulation, and fgl2(Tg) Tregs had increased immunosuppressive activity compared with fgl2(+/+) Tregs. To determine if FGL2 overexpression can promote tolerance, we transplanted fully mismatched cardiac allografts into fgl2(Tg) recipients. Fifty percent of cardiac grafts were accepted indefinitely in fgl2(Tg) recipients without any immunosuppression. Tolerant fgl2(Tg) grafts had increased numbers and proportions of Tregs and tolerant fgl2(Tg) mice had reduced proliferation to donor but not third party antigens. These data show that tolerance in fgl2(Tg) recipients involves changes in Treg and T cell activity that contribute to a higher intragraft Treg-to-T cell ratio and acceptance of fully mismatched allografts. PMID:26718313

  3. Fibrinogen and fibrin based micro and nano scaffolds incorporated with drugs, proteins, cells and genes for therapeutic biomedical applications

    PubMed Central

    Rajangam, Thanavel; An, Seong Soo A

    2013-01-01

    Over the past two decades, many types of natural and synthetic polymer-based micro- and nanocarriers, with exciting properties and applications, have been developed for application in various types of tissue regeneration, including bone, cartilage, nerve, blood vessels, and skin. The development of suitable polymers scaffold designs to aid the repair of specific cell types have created diverse and important potentials in tissue restoration. Fibrinogen (Fbg)- and fibrin (Fbn)-based micro- and nanostructures can provide suitable natural matrix environments. Since these primary materials are abundantly available in blood as the main coagulation proteins, they can easily interact with damaged tissues and cells through native biochemical interactions. Fbg- and Fbn-based micro and nanostructures can also be consecutively furnished/or encapsulated and specifically delivered, with multiple growth factors, proteins, and stem cells, in structures designed to aid in specific phases of the tissue regeneration process. The present review has been carried out to demonstrate the progress made with micro and nanoscaffold applications and features a number of applications of Fbg- and Fbn-based carriers in the field of biomaterials, including the delivery of drugs, active biomolecules, cells, and genes, that have been effectively used in tissue engineering and regenerative medicine. PMID:24106425

  4. Mechanical Transition from α-Helical Coiled-Coils to β-Sheets in Fibrin(ogen)

    PubMed Central

    Zhmurov, Artem; Kononova, Olga; Litvinov, Rustem I.; Dima, Ruxandra I.; Barsegov, Valeri; Weisel, John W.

    2012-01-01

    We characterized the α-to-β transition in α-helical coiled-coil connectors of human fibrin(ogen) molecule using biomolecular simulations of their forced elongation, and theoretical modeling. The force (F) - extension (X) profiles show three distinct regimes: (1) the elastic regime, in which the coiled-coils act as entropic springs (F < 100–125 pN; X < 7–8 nm); (2) the constant-force plastic regime, characterized by a force-plateau (F≈150 pN; X≈10–35 nm); and (3) the non-linear regime (F >175–200 pN; X > 40–50 nm). In the plastic regime, the three-stranded α-helices undergo a non-cooperative phase transition to form parallel three-stranded β-sheets. The critical extension of α-helices is 0.25 nm, and the energy difference between the α-helices and β-sheets is 4.9 kcal/mol per helical pitch. The soft α-to-β phase transition in coiled-coils might be a universal mechanism underlying mechanical properties of filamentous α-helical proteins. PMID:22953986

  5. PLASMA GENERATOR

    DOEpatents

    Foster, J.S. Jr.

    1958-03-11

    This patent describes apparatus for producing an electricity neutral ionized gas discharge, termed a plasma, substantially free from contamination with neutral gas particles. The plasma generator of the present invention comprises a plasma chamber wherein gas introduced into the chamber is ionized by a radiofrequency source. A magnetic field is used to focus the plasma in line with an exit. This magnetic field cooperates with a differential pressure created across the exit to draw a uniform and uncontaminated plasma from the plasma chamber.

  6. Solute removal capacity of high cut-off membrane plasma separators.

    PubMed

    Ohkubo, Atsushi; Kurashima, Naoki; Nakamura, Ayako; Miyamoto, Satoko; Iimori, Soichiro; Rai, Tatemitsu

    2013-10-01

    In vitro blood filtration was performed by a closed circuit using high cut-off membrane plasma separators, EVACURE EC-2A10 (EC-2A) and EVACURE EC-4A10 (EC-4A). Samples were obtained from sampling sites before the plasma separator, after each plasma separator, and from the ultrafiltrate of each separator. The sieving coefficient (S.C.) of total protein (TP), albumin (Alb), IgG, interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), fibrinogen (Fib), antithrombin III (AT-III), and coagulation factor XIII (FXIII) were calculated. The S.C. of each solute using EC-2A and EC-A4 were as follows; TP: 0.25 and 0.56, Alb: 0.32 and 0.73, IgG: 0.16 and 0.50, IL-6:0.73 and 0.95, IL-8:0.85 and 0.82, TNF-α: 1.07 and 0.99, Fib: 0 and 0, FXIII: 0.07 and 0.17, respectively. When compared with the conventional type of membrane plasma separators, EVACURE could efficiently remove cytokines while retaining coagulation factors such as fibrinogen. Moreover, EC-2A prevented protein loss, whereas EC-4A could remove approximately 50% of IgG. PMID:24107276

  7. Molecular cloning of cDNA for the B beta subunit of Xenopus fibrinogen, the product of a coordinately-regulated gene family.

    PubMed

    Bhattacharya, A; Shepard, A R; Moser, D R; Roberts, L R; Holland, L J

    1991-02-01

    Fibrinogen, the principal blood-clotting protein, is made up of three different subunits synthesized in the liver. In vitro administration of glucocorticoids to liver cells from the frog Xenopus laevis causes a dramatic increase in fibrinogen synthesis. Investigations of molecular mechanisms underlying this hormonal stimulation at the mRNA level require cDNA clones complementary to the mRNAs coding for the three fibrinogen subunits, called A alpha, B beta, and gamma. We describe here the isolation and characterization of cDNA clones for the B beta subunit of Xenopus fibrinogen. cDNA libraries in both plasmid (pBR322) and phage (lambda gt10) cloning vectors were constructed from frog liver mRNA and screened with a rat B beta cDNA. Clones thus isolated hybridized to two Xenopus liver mRNAs 2500 and 1800 bases long, the previously-determined sizes for B beta mRNAs. The identity of the plasmid clone B beta-27 was confirmed by hybridization-selection of complementary mRNA which translated in vitro into the B beta polypeptide, as determined by size and susceptibility to thrombin cleavage. lambda/B beta 10, a clone representing nearly all of the 2500-base B beta mRNA, was isolated from the phage cDNA library. The 3'-end of this clone includes a polyadenylation signal about 20 residues upstream of a stretch of 34 adenosine residues, which probably represents the 3'-poly(A) tail of the messenger RNA. lambda/B beta 10 lacks only 20 nucleotides of full-length B beta mRNA at the 5'-end and there is one major start site of transcription. The 2500-base B beta mRNA has a 700-base extension at the 3'-end that is not present in the 1800-base mRNA. The Xenopus laevis genome contains two or three genes for the B beta fibrinogen subunit. Using the cDNA clone as a probe, B beta mRNA was shown to be induced at least 20-fold by glucocorticoid treatment of purified parenchymal cells of Xenopus liver maintained in primary culture. PMID:2050271

  8. Control of the blood-polymer interface by plasma treatment.

    PubMed

    Dumitrascu, Nicoleta; Borcia, Catalin; Borcia, Gabriela

    2008-11-01

    Plasma that is generated using dielectric barrier discharge is used to modify the surface properties of polymers used in medicine, at atmospheric pressure. Treatments are performed on films of polyamide-6, high density polyethylene, polymethylmetacrylate, and polytetrafluorethylene, selected for their medical applications. The plasma treatment conditions are discussed, in relation with relevant parameters for the adhesion properties, like the surface energy components, interfacial tension, surface topography, structural changes, and chemical composition. The interface properties are analyzed using the most important fluids implicated in the interfacial events related to the coagulation process at the interface of blood-polymer surface, respectively, water, whole blood, fibrinogen, and albumin. The physical and chemical modification of the surface is theoretically favorable to the interaction of the polymer with the blood and its components, by means of interfacial tension reduction, polarity increase, cleaning, ordering of molecular chains, functionalization, and stabilization effects. PMID:18435402

  9. Plasma Medicine

    NASA Astrophysics Data System (ADS)

    Laroussi, M.; Kong, M. G.; Morfill, G.; Stolz, W.

    2012-05-01

    Foreword R. Satava and R. J. Barker; Part I. Introduction to Non-equilibrium Plasma, Cell Biology, and Contamination: 1. Introduction M. Laroussi; 2. Fundamentals of non-equilibrium plasmas M. Kushner and M. Kong; 3. Non-equilibrium plasma sources M. Laroussi and M. Kong; 4. Basic cell biology L. Greene and G. Shama; 5. Contamination G. Shama and B. Ahlfeld; Part II. Plasma Biology and Plasma Medicine: 6. Common healthcare challenges G. Isbary and W. Stolz; 7. Plasma decontamination of surfaces M. Kong and M. Laroussi; 8. Plasma decontamination of gases and liquids A. Fridman; 9. Plasma-cell interaction: prokaryotes M. Laroussi and M. Kong; 10. Plasma-cell interaction: eukaryotes G. Isbary, G. Morfill and W. Stolz; 11. Plasma based wound healing G. Isbary, G. Morfill and W. Stolz; 12. Plasma ablation, surgery, and dental applications K. Stalder, J. Woloszko, S. Kalghatgi, G. McCombs, M. Darby and M. Laroussi; Index.

  10. High-normal 2 h glucose is associated with defects of insulin secretion and predispose to diabetes in Chinese adults.

    PubMed

    Lin, Ziwei; Zhou, Jian; Li, Xiaowen; Song, Lige; Hou, Xuhong; Tang, Junling; Wang, Chen; Jia, Weiping

    2015-02-01

    The purpose of the study was to determine whether impaired beta-cell function exists in Chinese individuals within the normal range of glucose tolerance (NGT), and these individuals are predisposed to diabetes later in life. The cross-sectional study included 843 NGT subjects and 562 isolated impaired glucose tolerance (IGT) patients and the longitudinal study included 1,724 NGT subjects. Insulin secretion was assessed using indices derived from oral glucose tolerance test and adjusted by insulin resistance. NGT subjects were sub-divided into two groups: NGT-l (2hPG<125 mg/dl) and NGT-h (2hPG 125-140 mg/dl). Normal weight subjects were individuals with BMI<25 kg/m2, and overweight were with BMI≥25 kg/m2. In normal weight subjects, the first- and second-phase insulin secretion indices were significantly higher in NGT-h and NGT-l subjects compared with IGT subjects. However, in overweight subjects, first-phase insulin secretion index in NGT-h subjects was significantly lower than that in NGT-l subjects, but similar to that in IGT patients. The second-phase insulin secretion was comparable between NGT-h and NGT-l subjects. After an average follow-up of 43.80±11.25 months, totally 25 (1.5%) NGT subjects at baseline developed diabetes. The incidence rate of diabetes was higher in NGT-h overweight subjects (9.2%) than in NGT-l overweight subjects (1.5%) with a risk ratio (RR) reaching 6.655 [95% confidence interval (CI) 2.347-18.867]. This risk remained after adjustment for sex, age, BMI, systolic pressure, and diastolic pressure (RR 8.315, 95% CI 2.649-26.108). It is concluded that overweight NGT adults with high-normal 2hPG (≥125 mg/dl) had a defect in first-phase insulin secretion and were with the increasing risk for developing new diabetes. PMID:24711220

  11. Effect of high-normal compared with low-normal arterial pH on protein balances in automated peritoneal dialysis patients1234

    PubMed Central

    Bross, Rachelle; Wang, Huiyuan; Appell, Marilyn; Tso, Lai; Kopple, Joel D

    2009-01-01

    Background: Although the protein catabolic effects of metabolic acidosis are well established, it is unclear whether the entire reference range of arterial pH (7.37–7.44) is equivalent for protein balance. Objective: We undertook this study to test the hypothesis that in patients undergoing automated peritoneal dialysis, an arterial pH of 7.43–7.45, as compared with a pH of 7.36–7.38, is associated with more-positive nitrogen balances. Design: Eight stable subjects (5 men) aged 43.1 ± 15.3 y completed a randomized, crossover nitrogen balance study for ≥42 d. Arterial pH was varied by changing the daily doses of sodium citrate/citric acid and ammonium chloride. Results: The subjects attained mean (±SD) arterial pH values of 7.37 ± 0.01 and 7.44 ± 0.02 during the low-normal and high-normal pH phases, respectively. The higher arterial pH was associated with higher net nitrogen balances (3.22 ± 1.37 compared with 2.29 ± 2.18 g/d; P = 0.06), lower serum urea nitrogen (54.1 ± 13.7 compared with 64.4 ± 20.2 mg/dL; P = 0.01), higher fasting leucine flux (P = 0.02), and increased fasting total-body protein synthesis (P = 0.01) and degradation (P = 0.02). In 7 of 8 study subjects, nitrogen balances were more positive at the higher arterial pH (P = 0.004). There were no significant changes in anthropometric measurements, other biochemical measurements, and the mRNA content of selected proteins in skeletal muscle. Conclusion: This study suggests that in most stable automated peritoneal dialysis patients, a mean arterial pH of 7.44, as compared with 7.37, is associated with more-positive nitrogen balances. This trial was registered at clinical trials.gov as NCT00586131. PMID:19846545

  12. Altered plasma fibrin clot properties in essential thrombocythemia.

    PubMed

    Małecki, Rafał; Gacka, Małgorzata; Kuliszkiewicz-Janus, Małgorzata; Jakobsche-Policht, Urszula; Kwiatkowski, Jacek; Adamiec, Rajmund; Undas, Anetta

    2016-03-01

    Patients with increased thromboembolic risk tend to form denser fibrin clots which are relatively resistant to lysis. We sought to investigate whether essential thrombocythemia (ET) is associated with altered fibrin clot properties in plasma. Ex vivo plasma fibrin clot permeability coefficient (Ks), turbidimetry and clot lysis time (CLT) were measured in 43 consecutive patients with ET (platelet count from 245 to 991 × 10(3)/µL) and 50 control subjects matched for age, sex and comorbidities. Fibrinolysis proteins and inhibitors together with platelet activation markers were determined. Reduced Ks (-38%, p < 0.0001) and prolonged CLT (+34%, p < 0.0001) were observed in ET. The differences remained significant after adjustment for fibrinogen and platelet count. ET was associated with a slightly shorter lag phase (-5%, p = 0.01) and higher maximum absorbency of the turbidimetric curve (+6%, p < 0.001). The ET patients had higher plasma P-selectin by 193% (p < 0.00001) and platelet factor 4 (PF4) by 173% (p < 0.00001), with higher P-selectin observed in 19 (44%) patients with JAK-2 gene V617F mutation. Higher t-PA (+20%, p < 0.001), 23% higher plasminogen activator inhibitor-1, PAI-1 (+23%, p < 0.01) and unaltered thrombin-activatable fibrinolysis inhibitor, plasminogen and α2-antiplasmin activity were found in the ET group. Ks inversely correlated with fibrinogen, PF4 and C-reactive protein. CLT positively correlated only with PAI-1. Patients with ET display prothrombotic plasma fibrin clot phenotype including impaired fibrinolysis, which represents a new prothrombotic mechanism in this disease. PMID:25989112

  13. Zeolite Nanoparticles for Selective Sorption of Plasma Proteins

    NASA Astrophysics Data System (ADS)

    Rahimi, M.; Ng, E.-P.; Bakhtiari, K.; Vinciguerra, M.; Ahmad, H. Ali; Awala, H.; Mintova, S.; Daghighi, M.; Bakhshandeh Rostami, F.; de Vries, M.; Motazacker, M. M.; Peppelenbosch, M. P.; Mahmoudi, M.; Rezaee, F.

    2015-11-01

    The affinity of zeolite nanoparticles (diameter of 8-12 nm) possessing high surface area and high pore volume towards human plasma proteins has been investigated. The protein composition (corona) of zeolite nanoparticles has been shown to be more dependent on the plasma protein concentrations and the type of zeolites than zeolite nanoparticles concentration. The number of proteins present in the corona of zeolite nanoparticles at 100% plasma (in vivo state) is less than with 10% plasma exposure. This could be due to a competition between the proteins to occupy the corona of the zeolite nanoparticles. Moreover, a high selective adsorption for apolipoprotein C-III (APOC-III) and fibrinogen on the zeolite nanoparticles at high plasma concentration (100%) was observed. While the zeolite nanoparticles exposed to low plasma concentration (10%) exhibited a high selective adsorption for immunoglobulin gamma (i.e. IGHG1, IGHG2 and IGHG4) proteins. The zeolite nanoparticles can potentially be used for selectively capture of APOC-III in order to reduce the activation of lipoprotein lipase inhibition during hypertriglyceridemia treatment. The zeolite nanoparticles can be adapted to hemophilic patients (hemophilia A (F-VIII deficient) and hemophilia B (F-IX deficient)) with a risk of bleeding, and thus might be potentially used in combination with the existing therapy.

  14. Zeolite Nanoparticles for Selective Sorption of Plasma Proteins

    PubMed Central

    Rahimi, M.; Ng, E.-P.; Bakhtiari, K.; Vinciguerra, M.; Ahmad, H. Ali; Awala, H.; Mintova, S.; Daghighi, M.; Bakhshandeh Rostami, F.; de Vries, M.; Motazacker, M. M.; Peppelenbosch, M. P.; Mahmoudi, M.; Rezaee, F.

    2015-01-01

    The affinity of zeolite nanoparticles (diameter of 8–12 nm) possessing high surface area and high pore volume towards human plasma proteins has been investigated. The protein composition (corona) of zeolite nanoparticles has been shown to be more dependent on the plasma protein concentrations and the type of zeolites than zeolite nanoparticles concentration. The number of proteins present in the corona of zeolite nanoparticles at 100% plasma (in vivo state) is less than with 10% plasma exposure. This could be due to a competition between the proteins to occupy the corona of the zeolite nanoparticles. Moreover, a high selective adsorption for apolipoprotein C-III (APOC-III) and fibrinogen on the zeolite nanoparticles at high plasma concentration (100%) was observed. While the zeolite nanoparticles exposed to low plasma concentration (10%) exhibited a high selective adsorption for immunoglobulin gamma (i.e. IGHG1, IGHG2 and IGHG4) proteins. The zeolite nanoparticles can potentially be used for selectively capture of APOC-III in order to reduce the activation of lipoprotein lipase inhibition during hypertriglyceridemia treatment. The zeolite nanoparticles can be adapted to hemophilic patients (hemophilia A (F-VIII deficient) and hemophilia B (F-IX deficient)) with a risk of bleeding, and thus might be potentially used in combination with the existing therapy. PMID:26616161

  15. Zeolite Nanoparticles for Selective Sorption of Plasma Proteins.

    PubMed

    Rahimi, M; Ng, E-P; Bakhtiari, K; Vinciguerra, M; Ali Ahmad, H; Awala, H; Mintova, S; Daghighi, M; Bakhshandeh Rostami, F; de Vries, M; Motazacker, M M; Peppelenbosch, M P; Mahmoudi, M; Rezaee, F

    2015-01-01

    The affinity of zeolite nanoparticles (diameter of 8-12 nm) possessing high surface area and high pore volume towards human plasma proteins has been investigated. The protein composition (corona) of zeolite nanoparticles has been shown to be more dependent on the plasma protein concentrations and the type of zeolites than zeolite nanoparticles concentration. The number of proteins present in the corona of zeolite nanoparticles at 100% plasma (in vivo state) is less than with 10% plasma exposure. This could be due to a competition between the proteins to occupy the corona of the zeolite nanoparticles. Moreover, a high selective adsorption for apolipoprotein C-III (APOC-III) and fibrinogen on the zeolite nanoparticles at high plasma concentration (100%) was observed. While the zeolite nanoparticles exposed to low plasma concentration (10%) exhibited a high selective adsorption for immunoglobulin gamma (i.e. IGHG1, IGHG2 and IGHG4) proteins. The zeolite nanoparticles can potentially be used for selectively capture of APOC-III in order to reduce the activation of lipoprotein lipase inhibition during hypertriglyceridemia treatment. The zeolite nanoparticles can be adapted to hemophilic patients (hemophilia A (F-VIII deficient) and hemophilia B (F-IX deficient)) with a risk of bleeding, and thus might be potentially used in combination with the existing therapy. PMID:26616161

  16. Purification and characterization by fast-atom-bombardment mass spectrometry of the polymorphonuclear-leucocyte-elastase-generated A alpha (1-21) fragment of fibrinogen from human blood after incubation with calcium ionophore A23187.

    PubMed Central

    Dewey, R S; Liesch, J M; Williams, H R; Sugg, E E; Dolan, C A; Davies, P; Mumford, R A; Albers-Schönberg, G

    1992-01-01

    The stimulation of human blood with a Ca2+ ionophore, A23187, leads to activation of polymorphonuclear leucocytes (PMN) with release of small amounts of catalyticaly active elastase, as demonstrated by the formation of a characteristic product, the N-terminal A alpha (1-21) peptide of the Aa subunit of fibrinogen. The identity of the peptide was initially established by radioimmunoassay (r.i.a.) with an antibody raised to A alpha (1-21). We now provide independent confirmation of the formation of A alpha (1-21) by fast-atom-bombardment-m.s. analysis of the fractions separated chromatographically after spiking of plasma samples with peptide labelled with [2H8]Phe at position 8. Identity of the peptides was established on the basis of their chromatographic retention time and by the distinct peaks in the mass spectra of these fractions. The relative intensities of the molecular ions of natural and labelled peptides were measured. On the basis of a comparison of the peaks of similar intensities, the concentration of the natural peptide at the time of spiking was close (79%) to the amount obtained by r.i.a. An additional peptide, des-alanyl-A alpha (2-21), was also seen. The total amount of material measured by r.i.a. could be accounted for by the sum of these two provides. The addition of label and assay by m.s. has provided an independent physical-chemical method for identifying A alpha (1-21) as a characteristic product of PMN elastase release in whole blood, but which is absent in freshly drawn blood. PMID:1736899

  17. The regulatory T cell effector soluble fibrinogen-like protein 2 induces tubular epithelial cell apoptosis in renal transplantation.

    PubMed

    Zhao, Zitong; Yang, Cheng; Wang, Lingyan; Li, Long; Zhao, Tian; Hu, Linkun; Rong, Ruiming; Xu, Ming; Zhu, Tongyu

    2014-02-01

    Acute rejection (AR) hinders renal allograft survival. Tubular epithelial cell (TEC) apoptosis contributes to premature graft loss in AR, while the mechanism remains unclear. Soluble fibrinogen-like protein 2 (sFGL2), a novel effector of regulatory T cells (Treg), induces apoptosis to mediate tissue injury. We previously found that serum sFGL2 significantly increased in renal allograft rejection patients. In this study, the role of sFGL2 in AR was further investigated both in vivo and in vitro. The serum level of sFGL2 and the percentage of CD4(+)CD25(+)Foxp3(+) Treg in the peripheral blood were measured in renal allograft recipients with AR or stable renal function (n = 30 per group). The human TEC was stimulated with sFGL2, tumor necrosis factor (TNF)-α, or phosphate buffered saline and investigated for apoptosis in vitro. Apoptosis-associated genes expression in TEC was further assessed. Approval for this study was obtained from the Ethics Committee of Fudan University. Our results showed that the serum level of sFGL2, correlated with Treg in the peripheral blood, was significantly increased in the AR patients. In vitro, sFGL2 remarkably induced TEC apoptosis, with a significant up-regulation of proapoptotic genes, including CASP-3, CASP-8, CASP-9, CASP-10, TRADD, TNFSF10, FADD, FAS, FASLG, BAK1, BAD, BAX, and NF-KB1. However, no significant changes were observed in the expression of antiapoptotic genes, including CARD-18, NAIP, BCL2, IKBKB, and TBK1. Therefore, sFGL2, an effector of Treg, induces TEC apoptosis. Our study suggests that sFGL2 is a potential mediator in the pathogenesis of allograft rejection and provides novel insights into the role of Treg in AR. PMID:24414480

  18. Evolution of procalcitonin, C-reactive protein and fibrinogen levels in neutropenic leukaemia patients with invasive pulmonary aspergillosis or mucormycosis.

    PubMed

    Roques, Marjorie; Chretien, Marie Lorraine; Favennec, Camille; Lafon, Ingrid; Ferrant, Emmanuelle; Legouge, Caroline; Plocque, Alexia; Golfier, Camille; Duvillard, Laurence; Amoureux, Lucie; Bastie, Jean Noel; Maurin-Bernier, Lory; Dalle, Frederic; Caillot, Denis

    2016-06-01

    Unlike bacterial infections, the value of procalcitonin (PCT) in detecting fungal infections in leukaemia patients is not clear. To determine whether the monitoring of PCT coupled with C-reactive protein (CRP) and fibrinogen (Fib) could be helpful in the management of pulmonary aspergillosis (IPA) or mucormycosis (PM), we retrospectively analysed the evolution of PCT, CRP and Fib levels in 94 leukaemia patients with proven/probable IPA (n = 77) or PM (n = 17) from D-12 to D12 relative to IFI onset defined as D0. Overall, 2140 assays were performed. From D-12 to D0, 12%, 5% and 1.4% of patients had PCT >0.5, 1 and 1.5 μg l(-1) , respectively, while CRP was >50, 75 and 100 mg l(-1) in 84%, 70% and 57% and Fib was >4, 5 and 6 g l(-1) in 96%, 80% and 61% of cases respectively (P < 10(-7) ). The same trends were observed from D1 to D12. Overall, between D-12 and D12, only 6.4% of patients had PCT >1.5 μg l(-1) , while CRP >100 mg l(-1) and Fib >6 g l(-1) were observed in 80% and 75% of cases respectively (P < 10(-7) ). In leukaemia patients, IPA or PM was accompanied by a significant increase in CRP and Fib while PCT remained low. PMID:26931315

  19. Comparison of the serum fibrin-fibrinogen degradation products with cytokeratin 19 fragment as biomarkers in patients with lung cancer.

    PubMed

    So, Hee Jin; Hong, Seok-Il; Lee, Jin Kyung; Chang, Yoon Hwan; Kang, Sun Jung; Hong, Young Jun

    2014-09-01

    Lung cancer is one of the main causes of cancer-related mortality. The identification of early diagnostic biomarkers improved outcomes for lung cancer patients. Serum fibrin-fibrinogen degradation products (FDP) levels are elevated in numerous malignancies due to hemostatic alterations. The serum FDP levels were compared to the levels of cytokeratin 19 fragment antigen (CYFRA 21-1), another well-established biomarker. The serum samples from 193 lung cancer patients, 84 healthy controls and 106 patients with benign respiratory diseases were obtained. The serum FDP level was measured using the DR-70 immunoassay and the CYFRA 21-1 level was measured by electrochemiluminescence using the Roche Analytics E170. Receiver operating characteristics curves were used to assess the predictive sensitivity and specificity. The mean serum FDP level in lung cancer patients (35.01±229.02 μg/ml) was significantly higher compared to the 190 non-cancerous subjects (0.60±0.75 μg/ml; P=0.039). The mean serum CYFRA 21-1 level in lung cancer patients (4.50±6.67 ng/ml) was also significantly higher compared to the non-cancerous subjects (1.40±0.83 ng/ml; P<0.05). FDP exhibited clinical sensitivity and specificity of 86 and 75%, respectively, at an optimal cut-off at 0.67 μg/ml. CYFRA 21-1 exhibited clinical sensitivity and specificity of 77 and 74%, respectively, at a cut-off of 1.65 ng/ml. The serum FDP area under the curve (0.87) was slightly higher compared to CYFRA 21-1 (0.83). Therefore, it is apparent that serum FDP is comparable to CYFRA 21-1 as a lung cancer biomarker and can be used for clinical practice. PMID:25054020

  20. Preliminary Investigation of the Dissolution Behavior, Cytocompatibility, Effects of Fibrinogen Conformation and Platelet Adhesion for Radiopaque Embolic Particles

    PubMed Central

    Kehoe, Sharon; Tremblay, Marie-Laurence; Coughlan, Aisling; Towler, Mark R.; Rainey, Jan K.; Abraham, Robert J.; Boyd, Daniel

    2013-01-01

    Experimental embolic particles based on a novel zinc-silicate glass system have been biologically evaluated for potential consideration in transcatheter arterial embolization procedures. In addition to controlling the cytotoxicity and haemocompatibility for such embolic particles, its glass structure may mediate specific responses via dissolution in the physiological environment. In a 120 h in-vitro dissolution study, ion release levels for silicon (Si4+), sodium (Na+), calcium (Ca2+), zinc (Zn2+), titanium (Ti4+), lanthanum (La3+), strontium (Sr2+), and magnesium (Mg2+), were found to range from 0.04 to 5.41 ppm, 0.27–2.28 ppm, 2.32–8.47 ppm, 0.16–0.20 ppm, 0.12–2.15 ppm, 0.16–0.49 ppm and 0.01–0.12 ppm, respectively for the series of glass compositions evaluated. Initial release of Zn2+ (1.93–10.40 ppm) was only evident after 120 h. All compositions showed levels of cell viabilities ranging from 61.31 ± 4.33% to 153.7 ± 1.25% at 25%–100% serial extract dilutions. The conformational state of fibrinogen, known to induce thrombi, indicated that no changes were induced with respect of the materials dissolution by-products. Furthermore, the best-in-class experimental composition showed equivalency to contour PVA in terms of inducing platelet adhesion. The data generated here provides requisite evidence to continue to in-vivo pre-clinical evaluation using the best-in-class experimental composition evaluated. PMID:24956083

  1. Investigation of the adsorption of blood plasma proteins by activated carbon fiber material

    SciTech Connect

    Eretskaya, E.V.; Nikolaev, V.G.; Sergeev, V.P.; Stefanov, A.V.; Vovyanko, S.I.

    1987-01-01

    The authors study the adsorption of fibrinogen, albumin, and gamma globulin by carbon fibrous materials by physical immobilization of protein ligands on their surface. The adsorption of proteins from model solutions under standard conditions was studied by an indirect method according to the decrease in the concentration of the adsorbate in solution, determining the protein content. The adsorption of the same proteins from the plasma and their desorption from activated carbon fibrous materials were estimated by a direct radiometric method using /sup 125/I-labeled proteins.

  2. Plasma fibronectin promotes thrombus growth and stability in injured arterioles

    PubMed Central

    Ni, Heyu; Yuen, Peter S. T.; Papalia, Jessie M.; Trevithick, Jane E.; Sakai, Takao; Fässler, Reinhard; Hynes, Richard O.; Wagner, Denisa D.

    2003-01-01

    Mice lacking both of the best-known platelet ligands, von Willebrand factor and fibrinogen, can still form occlusive thrombi in injured arterioles. The platelets of these animals accumulate excessive amounts of fibronectin (FN). These observations led us to examine the contribution of plasma FN (pFN) to thrombus formation. Inactivation of the FN gene in FN conditional knockout mice reduced pFN levels to <2% and platelet FN to ≈20% of the levels in similarly treated control mice. The mice were then observed in a model of arterial injury to evaluate their capacity to form thrombi. The deficiency of pFN did not affect the initial platelet adhesion, but a delay of several minutes in thrombus formation was observed in the arterioles of pFN-deficient mice as compared with control mice. The thrombi that formed in the absence of pFN were stably anchored to the vessel wall but continuously shed platelets or small platelet clumps, thus slowing their growth significantly; the platelet/platelet cohesion was apparently diminished. Consequently the occlusion of pFN-deficient vessels was delayed, with the majority of vessels remaining patent at the end of the 40-min observation period. We conclude that, in addition to von Willebrand factor and fibrinogen, FN plays a significant role in thrombus initiation, growth, and stability at arterial shear rates and that deficiency in each of the three platelet ligands has its own specific impact on platelet plug formation. PMID:12606706

  3. Circulating levels of fibrin/fibrinogen degradation fragment E in normal pregnancy, and in association with intrauterine growth retardation and perinatal asphyxia.

    PubMed

    Gordon, Y B; Ratky, S M; Sola, C M; Lewis, J; Baker, L R; Chard, T

    1975-12-01

    Levels of fibrin/fibrinogen degradation products have been measured by aspecific and sensitive radioimmunoassay for degradation fragment E (FgE) in pregnant patients. Maternal FgE levels rose from the 16th week reaching a plateau at the 36th week in normal pregnancy. There was no correlation between maternal FgE levels and maternal age, parity or the occurrence of perinatal asphyxia. A minority of patients (5 per cent) with evidence of intrauterine growth retardation showed prolonged elevation of FgE levels. PMID:1203212

  4. Platelet-activating factor (PAF-acether) induces high- and low-affinity binding of fibrinogen to human platelets via independent mechanisms.

    PubMed Central

    Kloprogge, E; Akkerman, J W

    1986-01-01

    When human platelets are incubated with 500 nM-PAF-acether (platelet-activating factor. 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) under equilibrium conditions (60 min, 22 degrees C, non-stirred suspensions), two classes of fibrinogen binding sites are exposed: one class with a high affinity [Kd (7.2 +/- 2.1) X 10(-8) M, 2367 +/- 485 sites/platelet, n = 9] and one class with a low affinity [Kd (5.9 +/- 2.4) X 10(-7) M, 26972 +/- 8267 sites/platelet]. Preincubation with inhibitors of cyclo-oxygenase (acetylsalicylic acid, indomethacin) or thromboxane synthetase (UK 38.485) completely abolishes high-affinity binding, leaving low-affinity binding unchanged. In contrast, ADP scavengers (phosphocreatine/creatine kinase or phosphoenol pyruvate/pyruvate kinase) completely prevent low-affinity binding, leaving high-affinity binding unaltered. Initial binding studies (2-10 min incubation) confirm these findings with a major part of the binding being sensitive to ADP scavengers, a minor part sensitive to indomethacin and complete blockade with both inhibitors. Increasing the temperature to 37 degrees C decreases the number of low affinity-binding sites 6-fold without changing high-affinity binding. Aggregation, measured as the rate of single platelet disappearance, then depends on high-affinity binding at 10 nM-fibrinogen or less, whereas at 100 nM-fibrinogen or more low-affinity binding becomes predominant. These findings point at considerable platelet activation during binding experiments. However, arachidonate metabolism [( 3H]arachidonate mobilization and thromboxane synthesis) and secretion [( 14C]serotonin and beta-thromboglobulin) are about 10% or less of the amounts found under optimal conditions (5 units of thrombin/ml 37 degrees C, stirring). We conclude that PAF-acether induces little platelet activation under binding conditions. The amounts of thromboxane A2 and secreted ADP, however, are sufficient for initiating high- and low-affinity fibrinogen binding

  5. Effect of glucocorticoids, insulin and a growth promoting tripeptide on the biosynthesis of plasma proteins in serum-free hepatocyte cultures.

    PubMed

    Fouad, F M; Abd-El-Fattah, M; Scherer, R; Ruthenstroth-Bauer, G

    1981-01-01

    The effect of cortisol, dexamethasone, insulin and a liver cell growth promoting tripeptide on the secretion of plasma proteins into the medium of rat hepatocytes in monolayer cultures was studied. Cortisol and dexamethasone resulted in equal to or approximately 2.5-fold increase in the fibrinogen synthesis with general suppression of albumin and alpha-lipoprotein synthesis. On the other hand, insulin inhibited the biosynthesis of most plasma proteins except for the complement system and transferrin. Concentrations of alpha-lipoprotein, alpha-1-macroglobulin and haptoglobin were moderately elevated when the tripeptide Gly-His-Lys was applied in low concentration. PMID:7018103

  6. Plasma proteins in children with trichuris dysentery syndrome.

    PubMed Central

    Cooper, E S; Ramdath, D D; Whyte-Alleng, C; Howell, S; Serjeant, B E

    1997-01-01

    AIMS: To determine whether in Trichuris trichiura dysentery there is (1) evidence of a systemic inflammatory response, (2) evidence that the plasma protein disturbance has special characteristics compared with uninfected children in the endemic environment. METHODS: Three groups of children (age 1.6 to 11.4 years) were studied: 53 cases of trichuris dysentery syndrome (TDS), 16 cases of chronic non-secretory diarrhoea not infected with the parasite ("disease controls", DC), and 20 asymptomatic, parasite-free primary schoolchildren (normal controls, NC). C reactive protein, alpha 1 antitrypsin, caeruloplasmin, albumin, total globulin, fibrinogen, fibronectin, ferritin, and transferrin were measured on a single occasion for each. The study was thus a cross sectional descriptive survey for group comparison. Plasma viscosity was measured on admission for TDS and DC and repeated after six weeks and six months for TDS. RESULTS: Plasma C reactive protein, alpha 1 antitrypsin, total globulin, fibronectin, and viscosity were significantly higher in TDS than in NC. DC children also had acute phase protein elevations (C reactive protein, caeruloplasmin, viscosity). However, the increase in caeruloplasmin was specific to the DC group while an increase in fibronectin was specific to the TDS group. Serial measurement of viscosity in TDS showed a modest but significant fall during the six months following treatment. CONCLUSIONS: There is an acute phase response in intense trichuriasis and a specific elevation of plasma fibronectin. Plasma viscosity remains abnormally high six months after treatment, although lower than at diagnosis. Images PMID:9155675

  7. Hematologic and plasma biochemical reference values in Indian peafowl (Pavo cristatus).

    PubMed

    Samour, Jaime; Naldo, Jesus; Rahman, Habeeb; Sakkir, Mohammed

    2010-06-01

    Blood samples were collected from captive, adult, clinically normal Indian peafowl (Pavo cristatus) for hematologic and plasma biochemical analyses. Hematologic parameters investigated were total red blood cell count, hemoglobin, packed cell volume, fibrinogen, mean cell volume, mean cell hemoglobin, mean cell hemoglobin concentration, total white blood cell count, differential white blood cell count, and thrombocyte count. Plasma biochemical parameters investigated were alanine aminotransferase, alkaline phosphatase, amylase, aspartate aminotransferase, bile acids, total bilirubin, blood urea nitrogen, calcium, cholesterol, creatinine, creatine kinase, gamma glutamyltransferase, lactate dehydrogenase, glucose, iron, phosphorus, and uric acid, as well as plasma protein electrophoresis. Results were compared with values from studies done in houbara bustards (Chlamydotis undulata), kori bustards (Ardeotis kori), stone curlews (Burhinus oedicnemus), and taxonomically related species, including ring-necked pheasants (Phasianus colchicus), red-legged partridges (Alectoris rufa), Kashmir native fowl (Kashmirfavorella), and Bangladesh native, Fayoumi, and Assil fowl (Gallus domesticus). PMID:20806654

  8. Measurement of canine gastric vascular permeability to plasma proteins in the normal and protein-losing states

    SciTech Connect

    Wood, J.G.; Davenport, H.W.

    1982-04-01

    An isolated segment of the greater curvature of a dog's stomach was perfused at constant flow through a single cannulated artery with donor blood containing 131I-albumin, 125I-fibrinogen, and papaverine. Perfusion pressure was 30-50 mmHg, and venous pressure was set at 15 mmHg. Venous blood was collected in 1-min samples for 60 min. Filtration of fluid and loss of labeled proteins were calculated as the difference between measured arterial inflow and venous outflow. Permeability-surface area products (PS) were calculated for the proteins, and reflection coefficients (sigma) were calculated from solute flux and filtration. Intraarterial infusion of histamine (1.6-1.9 microgram . ml-1) increased filtration and PS and decreased sigma for albumin but not fibrinogen. When protein-losing was established by topical irrigation with 10 mM dithiothreitol in neutral solution, filtration and PS increased, and sigma for albumin but not fibrinogen decreased. Irrigation of the mucosa with 10 mM salicylic acid in 100 mN HCl caused bleeding that was quantitated by addition of 51Cr-erythrocytes to perfusing blood. Filtration and PS increased, and sigma for albumin but not fibrinogen decreased. Hematocrit of blood lost remained low during extensive mucosal damage. Effects of histamine infusion were attenuated or abolished by cimetidine (4 mg . kg-1 loading, 1.4 mg . kg-1 . h-1 continuous infusion) or by pyrilamine maleate (5 mg . kg-1 bolus injection at beginning of irrigation, repeated at 40-50 min). Pyrilamine attenuated or abolished effects of topical dithiothreitol or salicylic acid. We conclude that during protein loss caused by dithiothreitol or salicylic acid, histamine released within the mucosa causes increased vascular permeability for plasma proteins.

  9. Surface Assembly Configurations and Packing Preferences of Fibrinogen Mediated by the Periodicity and Alignment Control of Block Copolymer Nanodomains.

    PubMed

    Xie, Tian; Vora, Ankit; Mulcahey, Patrick J; Nanescu, Sonia E; Singh, Manpreet; Choi, Daniel S; Huang, Jeffrey K; Liu, Chi-Chun; Sanders, Daniel P; Hahm, Jong-In

    2016-08-23

    The ability to control the specific adsorption and packing behaviors of biomedically important proteins by effectively guiding their preferred surface adsorption configuration and packing orientation on polymeric surfaces may have utility in many applications such as biomaterials, medical implants, and tissue engineering. Herein, we investigate the distinct adhesion configurations of fibrinogen (Fg) proteins and the different organization behaviors between single Fg molecules that are mediated by the changes in the periodicity and alignment of chemically alternating nanodomains in thin films of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) block copolymer (BCP). Specifically, the adsorption characteristics of individual Fg molecules were unambiguously resolved on four different PS-b-PMMA templates of dsa PS-b-PMMA, sm PS-b-PMMA, com PS-b-PMMA, and PS-r-PMMA. By direct visualization through high resolution imaging, the distinct adsorption and packing configurations of both isolated and interacting Fg molecules were determined as a function of the BCP template-specific nanodomain periodicity, domain alignment (random versus fully aligned), and protein concentration. The three dominant Fg adsorption configurations, SP∥, SP⊥, and TP, were observed and their occurrence ratios were ascertained on each PS-b-PMMA template. During surface packing, the orientation of the protein backbone was largely governed by the periodicity and alignment of the underlying PS-b-PMMA nanodomains whose specific direction was explicitly resolved relative to the polymeric nanodomain axis. The use of PS-b-PMMA with a periodicity much smaller than (and comparable to) the length of Fg led to a Fg scaffold with the protein backbone aligned parallel (and perpendicular) to the nanodomain major axis. In addition, we have successfully created fully Fg-decorated BCP constructs analogous to two-dimensional Fg crystals in which aligned protein molecules are arranged either side-on or end

  10. Effect of hepatocyte-stimulating factor and glucocorticoids on plasma fibronectin levels.

    PubMed Central

    Amrani, D L; Mauzy-Melitz, D; Mosesson, M W

    1986-01-01

    We evaluated the effects of hepatocyte-stimulating factor (HSF) and a glucocorticoid (dexamethasone) on changes in the levels, in vivo and in vitro, of plasma fibronectin (Fn), a glycoprotein that is synthesized and secreted by hepatocytes. In turpentine-treated chickens, plasma levels of Fn, which peaked at 48 h (whereas fibrinogen levels were maximum at 72 h) rose 200-250% over basal levels, whereas albumin levels decreased by 20-40%. Corticosterone levels in serum samples taken between 5 and 48 h after injection revealed a 124% increase in hormone levels at 24 h in turpentine-treated chickens. We also showed that circulating HSF levels were maximal 8 to 12 h after injection and that HSF activity, as assessed by molecular-exclusion chromatography, was eluted in the 30-45 kDa range. Addition of either serum-derived HSF or dexamethasone (2 nM) to chick hepatocyte cultures resulted in a 130-150% increase in secreted Fn as well as in fibrinogen. When HSF and dexamethasone were added together, a 360-489% increase in the secreted levels of both proteins was found. Chicken mononuclear phagocytic cells treated with lipopolysaccharide secreted an HSF activity that was eluted in two peaks, a minor peak at approximately 70 kDa and a major peak in the 25-40 kDa range. Addition of mononuclear-cell-derived HSF resulted in a greater increase in Fn levels than did the addition of serum HSF. These findings indicate that Fn, like fibrinogen, is an acute-phase protein, the production of which, at least in chickens, is stimulated by HSF and glucocorticoids in an additive manner. PMID:3099768

  11. Localization of the equine IgG-binding domain in the fibrinogen-binding protein (FgBP) of Streptococcus equi subsp. equi.

    PubMed

    Meehan, Mary; Lewis, Melanie J; Byrne, Caroline; O'Hare, David; Woof, Jenny M; Owen, Peter

    2009-08-01

    Fibrinogen-binding protein (FgBP, also termed SeM) is a cell-wall-associated anti-phagocytic M-like protein of the equine pathogen Streptococcus equi subsp. equi, and binds fibrinogen (Fg) and IgG. FgBP binds Fg avidly through residues located at the extreme N terminus of the molecule, whereas the IgG-binding site is more centrally located between the A and B repeats. FgBP binds equine IgG4 and IgG7 subclasses through interaction with the CH2-CH3 interdomain region of IgG-Fc, and possesses overlapping Fc-binding sites with protein A and protein G. In this study, FgBP truncates containing defined internal deletions were used to identify a stretch of 14 aa (residues 335-348) critical for IgG binding. Protein chimeras consisting of the non-IgG-binding alpha-helical coiled-coil M5 protein fused to FgBP sequences were used to identify a minimal equine IgG-binding domain consisting of residues 329-360. Competition ELISA tests suggested that IgG does not compromise Fg binding and vice versa. PMID:19423628

  12. An echistatin C-terminal peptide activates GPIIbIIIa binding to fibrinogen, fibronectin, vitronectin and collagen type I and type IV.

    PubMed Central

    Wright, P S; Saudek, V; Owen, T J; Harbeson, S L; Bitonti, A J

    1993-01-01

    Integrin binding to proteins often involves recognition of domains containing the arginine-glycine-aspartate (RGD) motif. Different binding affinities and specificities of the integrin-ligand protein interactions involve additional protein domains. The n.m.r. structure of the snake-venom protein echistatin suggested that the C-terminal portion of the molecule might be important, in addition to the RGD domain, in binding to the integrin glycoprotein IIbIIIa (GPIIbIIIa) [Saudek, Atkinson and Pelton (1991) Biochem. 30, 7369-7372]. The synthetic C-terminal peptide, echistatin-(40-49), PRNPHKGPAT, (1) inhibited binding of GPIIbIIIa to immobilized echistatin (IC50 3-6 mM), but did not inhibit binding of GPIIbIIIa to immobilized fibrinogen (up to 5 mM peptide), (2) activated GPIIbIIIa binding to fibronectin and vitronectin, usual ligands for the activated integrin, (3) activated binding of GPIIbIIIa to collagen type I and type IV, proteins not usually regarded as ligands for the integrin, and (4) stimulated 125I-fibrinogen binding by human platelets. These findings argue for an interaction of this non-RGD domain in echistatin with GPIIbIIIa, leading to activation of the integrin and extension of the ligand specificity to include immobilized collagen. PMID:7687129

  13. Human immunoglobulin G recognizing fibrinogen-binding surface proteins is protective against both Staphylococcus aureus and Staphylococcus epidermidis infections in vivo.

    PubMed

    Vernachio, John H; Bayer, Arnold S; Ames, Brenda; Bryant, Dawn; Prater, Bradley D; Syribeys, Peter J; Gorovits, Elena L; Patti, Joseph M

    2006-02-01

    A human donor-selected immunoglobulin G for intravenous injection (IGIV) product with elevated titers against the staphylococcal fibrinogen-binding MSCRAMM proteins ClfA and SdrG (INH-A21) was tested in vitro and in vivo. INH-A21 contained a significantly increased ability to inhibit the fibrinogen-binding activity of recombinant forms of both ClfA and SdrG. Evaluation of the opsonizing potential of INH-A21 was evaluated using fluorescently labeled bacteria; this assay indicated an increase in phagocytic activity compared to normal IGIV. The prophylactic efficacy of INH-A21 against an intraperitoneal challenge of methicillin-resistant Staphylococcus epidermidis (MRSE) was evaluated in a neonatal rat model. INH-A21 was also evaluated for prophylactic and therapeutic efficacy in a rabbit model of catheter-induced aortic valve infective endocarditis caused by either MRSE or methicillin-resistant Staphylococcus aureus (MRSA). Results from the in vivo models demonstrated potent prophylactic and therapeutic efficacy against both MRSE and MRSA. These data suggest that INH-A21 may be an important tool for the prevention and treatment of staphylococcal infections, especially in high-risk populations. PMID:16436704

  14. Human Immunoglobulin G Recognizing Fibrinogen-Binding Surface Proteins Is Protective against both Staphylococcus aureus and Staphylococcus epidermidis Infections In Vivo

    PubMed Central

    Vernachio, John H.; Bayer, Arnold S.; Ames, Brenda; Bryant, Dawn; Prater, Bradley D.; Syribeys, Peter J.; Gorovits, Elena L.; Patti, Joseph M.

    2006-01-01

    A human donor-selected immunoglobulin G for intravenous injection (IGIV) product with elevated titers against the staphylococcal fibrinogen-binding MSCRAMM proteins ClfA and SdrG (INH-A21) was tested in vitro and in vivo. INH-A21 contained a significantly increased ability to inhibit the fibrinogen-binding activity of recombinant forms of both ClfA and SdrG. Evaluation of the opsonizing potential of INH-A21 was evaluated using fluorescently labeled bacteria; this assay indicated an increase in phagocytic activity compared to normal IGIV. The prophylactic efficacy of INH-A21 against an intraperitoneal