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1.
Nature ; 590(7847): 566-570, 2021 02.
Article in English | MEDLINE | ID: mdl-33627809

ABSTRACT

When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning1; this phenomenon has been a mystery in nuclear physics for over 40 years2,3. The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum4-12. Nevertheless, the consensus is that excitation of collective vibrational modes generates the intrinsic spin before the nucleus splits (pre-scission). Here we show that there is no significant correlation between the spins of the fragment partners, which leads us to conclude that angular momentum in fission is actually generated after the nucleus splits (post-scission). We present comprehensive data showing that the average spin is strongly mass-dependent, varying in saw-tooth distributions. We observe no notable dependence of fragment spin on the mass or charge of the partner nucleus, confirming the uncorrelated post-scission nature of the spin mechanism. To explain these observations, we propose that the collective motion of nucleons in the ruptured neck of the fissioning system generates two independent torques, analogous to the snapping of an elastic band. A parameterization based on occupation of angular momentum states according to statistical theory describes the full range of experimental data well. This insight into the role of spin in nuclear fission is not only important for the fundamental understanding and theoretical description of fission, but also has consequences for the γ-ray heating problem in nuclear reactors13,14, for the study of the structure of neutron-rich isotopes15,16, and for the synthesis and stability of super-heavy elements17,18.

2.
Circulation ; 104(12): 1336-42, 2001 Sep 18.
Article in English | MEDLINE | ID: mdl-11560847

ABSTRACT

BACKGROUND: Vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule (ICAM)-1, and E-selectin mediate adhesion and transmigration of leukocytes to the vascular endothelial wall and may promote plaque growth and instability. In a prospective study, we evaluated the effect of soluble adhesion molecules on the risk of future cardiovascular events among patients with angiographically documented coronary artery disease (CAD). Methods and Results- -We obtained baseline samples from a prospective cohort of 1246 patients with CAD. Besides various markers of inflammation, soluble VCAM-1 (sVCAM-1), sICAM-1, and sE-selectin were determined. Follow-up information on cardiovascular events was obtained (mean, 2.7; maximum, 4.1 years). Independently higher levels of sVCAM-1 (1932 versus 1128 ng/mL; P<0.0001), sICAM-1 (353 versus 287 ng/mL; P=0.015), and sE-selectin (81 versus 63 ng/mL; P=0.003) were observed in patients with future death from cardiovascular causes. In a multivariate model, fatal risk was 2.1-fold (1.1 to 4.0) higher in patients within the top quartile of baseline sVCAM-1 concentrations compared with lower quartiles. This association was present independent of general inflammatory response as reflected by low or high C-reactive protein (hs-CRP) levels. In a model that simultaneously controlled for all inflammatory and soluble adhesion markers determined, only sVCAM-1 remained independently significant for future fatal cardiovascular events, with a 2.8-fold increase in risk (P=0.003). CONCLUSIONS: Soluble adhesion molecules sVCAM-1, sICAM-1, and sE-selectin were significantly related to future death from cardiovascular causes among patients with documented CAD. Especially sVCAM-1 added to the predictive value of classic risk factors and hs-CRP in determining the risk of future cardiovascular death.


Subject(s)
Cell Adhesion Molecules/blood , Coronary Disease/blood , Coronary Disease/mortality , Aged , C-Reactive Protein/analysis , Cohort Studies , E-Selectin/blood , Female , Follow-Up Studies , Germany/epidemiology , Humans , Intercellular Adhesion Molecule-1/blood , Male , Middle Aged , Predictive Value of Tests , Proportional Hazards Models , Prospective Studies , Risk Factors , Sensitivity and Specificity , Survival Rate , Vascular Cell Adhesion Molecule-1/blood
3.
Circulation ; 104(1): 25-31, 2001 Jul 03.
Article in English | MEDLINE | ID: mdl-11435333

ABSTRACT

BACKGROUND: The number of infectious pathogens to which an individual has been exposed (infectious burden) may correlate with coronary artery disease (CAD). In a prospective study, we evaluated the effect of 8 pathogens and the aggregate pathogen burden on the risk for future fatal cardiac events among patients with angiographically documented CAD. Methods and Results-In 1018 patients, IgG or IgA antibodies to herpes simplex virus types 1 and 2, cytomegalovirus, Epstein-Barr virus, Haemophilus influenzae, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Helicobacter pylori were determined. Moreover, highly sensitive C-reactive protein was measured. Follow-up information on cardiovascular events was obtained (mean 3.1 years, maximum 4.3 years). Seropositivities to Epstein-Barr virus (P=0.001), H pylori (P=0.002), and herpes simplex virus type 2 (P=0.045) were independently associated with the future risk of cardiovascular death. An increasing number for pathogen burden was significantly predictive of the long-term prognosis (P<0.0001). Infectious burden divided into 0 to 3, 4 or 5, and 6 to 8 seropositivities was associated with an increasing mortality of 3.7%, 7.2%, and 12.6%, respectively. Patients seropositive to >5 pathogens compared with those seropositive to <4 pathogens had a 5.1 (1.4 to 18.3) higher risk of future cardiac death. This result was mainly driven by the pathogen burden of seropositivities to Herpesviridae (P<0.0001). The prognostic impact of total or viral pathogen burden was independent of the C-reactive protein level. CONCLUSIONS: These results support the hypothesis that the number of infectious pathogens to which an individual has been exposed independently contributes to the long-term prognosis in patients with documented CAD.


Subject(s)
Bacterial Infections/diagnosis , Coronary Disease/microbiology , Virus Diseases/diagnosis , Antibodies, Bacterial/blood , Antibodies, Viral/blood , Bacterial Infections/epidemiology , Bacterial Infections/immunology , C-Reactive Protein/metabolism , Chlamydophila pneumoniae/immunology , Comorbidity , Coronary Disease/diagnosis , Coronary Disease/epidemiology , Coronary Disease/immunology , Cytomegalovirus/immunology , Female , Follow-Up Studies , Haemophilus influenzae/immunology , Helicobacter pylori/immunology , Herpesvirus 1, Human/immunology , Herpesvirus 2, Human/immunology , Herpesvirus 4, Human/immunology , Humans , Immunoglobulin G/blood , Male , Middle Aged , Mycoplasma pneumoniae/immunology , Odds Ratio , Prognosis , Risk Assessment , Seroepidemiologic Studies , Virus Diseases/epidemiology , Virus Diseases/immunology
4.
Circulation ; 103(24): 2915-21, 2001 Jun 19.
Article in English | MEDLINE | ID: mdl-11413080

ABSTRACT

BACKGROUND: Prospective data relating previous exposure to cytomegalovirus (CMV) to the risk of cardiac mortality are controversial. We investigated the effect of previous exposure to CMV infection on the risk of future cardiac disease-related death in relation to an underlying inflammatory response. METHODS AND RESULTS: coronary angiography was performed in 1134 subjects, and 989 patients with documented coronary artery disease were studied prospectively. CMV-IgG titers and interleukin (IL)-6 levels were measured before angiography. Increasing titers of CMV correlated with the elevation of IL-6 levels (P<0.001) after adjustment for possible confounders. All patients were followed up for a median of 3.1 years (maximum 4.3 years). During follow-up, 96 patients died, 70 of cardiac disease. Overall, CMV seropositivity was not related to cardiac mortality after adjustment for confounding variables (P=0.19). In contrast, in patients with elevated IL-6 levels (>/=11.9 pg/mL, median level), CMV seropositivity was independently associated with a 3.2-fold (95% CI 1.4 to 7.3, P=0.007) increase in risk of future cardiac death, whereas in individuals without IL-6 elevation, previous CMV infection had no effect on cardiac mortality. CONCLUSIONS: MV seropositivity in patients with an inflammatory response is independently associated with future cardiac mortality, whereas this association is lost in patients who do not demonstrate an inflammatory response. These data support the hypothesis that the atherosclerotic effects of CMV are mediated through an underlying inflammatory response.


Subject(s)
Coronary Disease/blood , Coronary Disease/mortality , Cytomegalovirus Infections/blood , Cytomegalovirus Infections/diagnosis , Interleukin-6/blood , Aged , Antibodies, Viral/blood , C-Reactive Protein/metabolism , Cholesterol, HDL/blood , Coronary Angiography , Coronary Disease/complications , Coronary Disease/diagnosis , Cytomegalovirus Infections/complications , Enzyme-Linked Immunosorbent Assay , Female , Follow-Up Studies , Germany , Humans , Inflammation/blood , Inflammation/complications , Male , Middle Aged , Odds Ratio , Predictive Value of Tests , Prognosis , Prospective Studies , Regression Analysis , Risk Assessment , Risk Factors , Survival Rate
5.
Circulation ; 104(25): 3125-31, 2001 Dec 18.
Article in English | MEDLINE | ID: mdl-11748112

ABSTRACT

BACKGROUND: Complement activation during reperfusion of ischemic myocardium augments myocardial injury, and complement inhibition with C1-esterase inhibitor (C1-INH) at the time of reperfusion exerts marked cardioprotective effects in experimental studies. Application of C1-INH in newborns, however, was recently reported to have dangerous and even lethal side effects. This study addresses the essential role of dosage in studies using C1-INH. METHODS AND RESULTS: Cardioprotection by C1-INH was examined in a pig model with 60 minutes of coronary occlusion followed by 120 minutes of reperfusion. C1-INH was administered intravenously 5 to 10 minutes before coronary reperfusion without heparin at a dose of 40, 100, and 200 IU/kg body wt. Compared with the NaCl controls, C1-INH 40 IU/kg reduced myocardial injury (44.1+/-13.8% versus 76.7+/-4.6% necrosis of area at risk, P/=100 IU/kg) of C1-INH will provoke detrimental side effects, probably via its procoagulatory action.


Subject(s)
Complement C1 Inactivator Proteins/pharmacology , Myocardial Ischemia/complications , Reperfusion Injury/prevention & control , Anaphylatoxins/metabolism , Animals , Blood Gas Analysis , Cardiac Output/drug effects , Complement C1 Inactivator Proteins/metabolism , Coronary Circulation/drug effects , Creatine Kinase/blood , Creatine Kinase/drug effects , Dose-Response Relationship, Drug , Heart Ventricles/drug effects , Heart Ventricles/pathology , Heart Ventricles/physiopathology , Hemodynamics/drug effects , Lactic Acid/blood , Microscopy, Electron , Myocardial Ischemia/blood , Myocardial Ischemia/physiopathology , Myocardium/metabolism , Myocardium/pathology , Myocardium/ultrastructure , Necrosis , Oxygen/blood , Partial Pressure , Reperfusion Injury/etiology , Swine , Troponin T/blood , Troponin T/drug effects
6.
J Am Coll Cardiol ; 33(5): 1365-71, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10193740

ABSTRACT

OBJECTIVES: The impact of infection-associated antiphospholipid antibodies (APA) on endothelial cell activation, blood coagulation and fibrinolysis was evaluated in patients with infective endocarditis with and without major embolic events. BACKGROUND: An embolic event is a common and severe complication of infective endocarditis. Despite the fact that APAs are known to be associated with infectious diseases, their pathogenic role in infective endocarditis has not been clearly defined. METHODS: The relationship among the occurrence of major embolic events, echocardiographic vegetation size, endothelial cell activation, thrombin generation, fibrinolysis and APA was examined in 91 patients with definite infective endocarditis, including 26 patients with embolic events and 65 control subjects without embolic events. RESULTS: Overall, 14.3% of patients exhibited elevated APA levels. Embolic events occurred more frequently in patients with elevated levels of APA than in patients without (61.5% vs. 23.1%; p = 0.008). Patients with elevated levels of APA showed higher levels of prothrombin-fragment F1 +2 (p = 0.005), plasminogen-activator inhibitor 1 (p = 0.0002), von Willebrand factor (p = 0.002) and lower levels of activated protein C (p = 0.001) than patients with normal levels of APA. Thrombin generation and endothelial cell activation were both positively correlated with levels of APA. The occurrence of elevated APA levels was frequently associated with structural valve abnormalities (p = 0.01) and vegetations >1.3 cm (p = 0.002). CONCLUSIONS: Infection-associated elevated APA levels in patients with infective endocarditis are related to endothelial cell activation, thrombin generation and impairment of fibrinolysis. This may contribute to the increased risk for major embolic events in these patients.


Subject(s)
Antibodies, Antiphospholipid/analysis , Endocarditis, Bacterial/immunology , Intracranial Embolism and Thrombosis/immunology , Adult , Aged , Biomarkers/blood , Cerebral Angiography , Echocardiography, Transesophageal , Endocarditis, Bacterial/complications , Endocarditis, Bacterial/diagnosis , Enzyme-Linked Immunosorbent Assay , Female , Fibrinolysis , Follow-Up Studies , Heart Valves/diagnostic imaging , Humans , Intracranial Embolism and Thrombosis/diagnosis , Intracranial Embolism and Thrombosis/etiology , Male , Middle Aged , Plasminogen Activator Inhibitor 1/metabolism , Prognosis , Protein C/metabolism , Retrospective Studies , Risk Factors , Thrombin/metabolism , Tomography, X-Ray Computed , Ultrasonography, Doppler
7.
J Am Coll Cardiol ; 26(7): 1637-42, 1995 Dec.
Article in English | MEDLINE | ID: mdl-7594097

ABSTRACT

OBJECTIVES: This study was performed to evaluate the efficacy of peri-interventional treatment with recombinant hirudin (r-hirudin [HBW 023]) compared with heparin in the prevention of troponin T release in patients with unstable angina. BACKGROUND: Percutaneous transluminal coronary angioplasty in patients with unstable angina is associated with a high risk of acute thrombotic complications. METHODS: Serial troponin T measurements were performed in 61 patients with unstable angina during the 48-h observation period after coronary angioplasty of the ischemia-related lesion. Patients were randomly assigned to peri-interventional intravenous treatment with either r-hirudin (dosage group I: 0.3-mg/kg body weight bolus, 0.12 mg/kg per h for 24 h; dosage group II: 0.5-mg/kg bolus, 0.24 mg/kg per h for 24 h) or heparin (150-IU/kg bolus, 20 IU/kg per h for 24 h). All patients received acetylsalicylic acid before coronary angiography. After 24 h, patients received a constant low dose infusion of either hirudin (0.04 mg/kg per h) or heparin (7 IU/kg per h) for another 24 h. The power of the study to detect a decrease in abnormal troponin T levels from 60% (heparin group) to 20% (combined r-hirudin groups) was 88%. RESULTS: Serial troponin T measurements revealed two peaks within the 48 h after coronary angioplasty in the heparin but not the hirudin groups. An elevated serum troponin T concentration (> 0.2 ng/ml) within 48 h of coronary angioplasty was found in 9 (24%) of 38 patients in the hirudin groups (5 [25%] of 20 in dosage group I; 4 [22%] of 18 in dosage group II) compared with 11 (58%) of 19 in the heparin group (p = 0.01). We observed major cardiac events (death, myocardial infarction, abrupt vessel closure) in 1 (4.8%) of 21 patients in dosage group I, 1 (5.3%) of 19 in dosage group II and 3 (14.3%) of 21 in the heparin group (p = 0.33). CONCLUSIONS: In this pilot trial, hirudin appears to be superior to heparin in preventing troponin T release after coronary angioplasty.


Subject(s)
Angina, Unstable/therapy , Angioplasty, Balloon, Coronary , Hirudin Therapy , Hirudins/analogs & derivatives , Troponin/blood , Angina, Unstable/blood , Angina, Unstable/diagnostic imaging , Angina, Unstable/pathology , Angioplasty, Balloon, Coronary/adverse effects , Coronary Angiography , Heparin/therapeutic use , Humans , Myocardium/pathology , Necrosis , Pilot Projects , Premedication , Recombinant Proteins/therapeutic use , Thrombosis/etiology , Thrombosis/prevention & control , Troponin T
8.
Arterioscler Thromb Vasc Biol ; 21(10): 1668-73, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11597943

ABSTRACT

P-selectin is a cellular adhesion molecule that mediates the interaction of activated endothelial cells or platelets with leukocytes. Increased levels of soluble P-selectin have been reported in various cardiovascular disorders. We measured serum soluble P-selectin levels as well as 3 polymorphisms of the P-selectin gene (C-2123G, A-1969G, and Thr715Pro) in a large cohort of patients with documented coronary artery disease (n=869) and a healthy control group (n=334). The 3 P-selectin polymorphisms were strongly associated with P-selectin levels and altogether explained 7.3% and 18.6% of the P-selectin variability in patients and controls, respectively. Genotype distributions did not significantly differ between patients and controls. P-selectin levels were increased in patients younger than 55 years of age compared with controls (135.2 vs 114.3 ng/mL, P<0.01). On the contrary, patients older than 65 years of age had significantly lower P-selectin levels than did controls (121.5 vs 134.7 ng/mL, P<0.02). In intermediate age groups, P-selectin levels did not significantly differ between the 2 groups. In conclusion, this study revealed a strong association between P-selectin gene polymorphisms and serum P-selectin levels and a complex age-dependent relation between soluble P-selectin levels and coronary artery disease, which suggests that this molecule might have different roles in the atherothrombotic process.


Subject(s)
Coronary Artery Disease/etiology , Coronary Artery Disease/genetics , P-Selectin/blood , P-Selectin/genetics , Polymorphism, Single Nucleotide , Cohort Studies , Coronary Artery Disease/blood , Female , Humans , Male , Middle Aged , Risk Factors , Smoking/adverse effects
9.
Hamostaseologie ; 25(3): 272-8; quiz 279-80, 2005 Aug.
Article in German | MEDLINE | ID: mdl-16113751

ABSTRACT

Anticoagulation during renal replacement therapy is recommended to avoid thrombosis of the filter devices and to maintain the blood flow. However, in the case of multiorgan failure and sepsis, an imminent bleeding complication in patients with acute renal failure may cause the need for an extracorporeal circulation without anticoagulation. The most common drug used in renal replacement therapy is the unfractionated heparin (UFH). With low molecular weight heparin (LMWH) good experiences are reported, too. Based on the level of evidence from clinical studies plasma measurement of heparin is indispensable for patients with renal insufficiency. The activated whole blood clotting time (ACT), the activated partial thromboplastin time (aPTT), and the determination of the anti-factor Xa activity (anti Xa) with chromogenic substrates are available as routine as well as as point-of-care tests. To monitor plasma levels of LMWH the anti Xa assay serves exclusively as a suitable monitoring. The anti Xa assay using chromogenic substrates is the most specific and valid one for monitoring heparin therapy. In lack of large controlled studies for the anticoagulation therapy and its monitoring with the anti Xa test in acute renal failure, the current experiences are based on the results of chronic renal replacement therapy.


Subject(s)
Heparin/therapeutic use , Renal Dialysis/methods , Anticoagulants/therapeutic use , Drug Monitoring , Humans , Kidney Failure, Chronic/therapy
10.
Stroke ; 31(9): 2127-33, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10978041

ABSTRACT

BACKGROUND AND PURPOSE: Chronic infection with Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus (CMV), and herpes simplex virus (HSV) has been implicated in the pathogenesis of atherosclerosis. The carotid intima-media thickness (IMT) can be taken to indicate early atherosclerosis, the presence of a carotid stenosis is a marker of a manifest carotid atherosclerosis, and an increase in arterial stiffness is used as marker of structural and functional changes in an atherosclerotic vessel wall. METHODS: In 504 patients (75% men; mean age 62.9 [SD 10] years), we measured the IMT and the elastic pressure modulus (EP; n=445) of the common carotid artery and the prevalence of a internal or external carotid artery stenosis. Blood samples were taken, and antibodies against C pneumoniae, H pylori, CMV, and HSV types 1 and 2 were evaluated. Statistical evaluation was performed with regression procedures and multivariate logistic regression analyses. RESULTS: Seropositivity for C pneumoniae was an independent predictor for a combined end point of highest category of IMT and carotid artery stenosis (OR 1.8, 95% CI 1.1 to 3.1; adjusted) for IgG titers. Independently, CMV increased the risk for the combined end point (OR 1.7, 95% CI 1.1 to 2.8; adjusted) for IgG titers and for IgA titers (OR 2.3, 95% CI 1.1 to 4. 9; adjusted). We found a significant correlation between IgG antibodies against CMV and EP; HSV type 2 IgG titers were associated with IMT and carotid stenosis, but the latter results were no longer significant after adjustment. There was no association with H pylori or HSV type 1. CONCLUSIONS: We found a significant association of IgG antibodies against C pneumoniae and CMV with early and advanced carotid atherosclerosis. CMV was also correlated to functional changes of the carotid artery, but this could not be confirmed after adjustment.


Subject(s)
Arteriosclerosis/microbiology , Carotid Arteries/microbiology , Carotid Stenosis/etiology , Chlamydophila pneumoniae , Cytomegalovirus , Helicobacter pylori , Simplexvirus , Arteriosclerosis/virology , Carotid Arteries/pathology , Carotid Arteries/virology , Chlamydia Infections/complications , Cytomegalovirus Infections/complications , Helicobacter Infections/complications , Herpes Simplex/complications , Humans , Male , Middle Aged , Regression Analysis
11.
J Comp Neurol ; 174(3): 397-416, 1977 Aug 01.
Article in English | MEDLINE | ID: mdl-903413

ABSTRACT

The synthesis and distribution of 3H-leucine labeled protein was studied under conditions of diurnal lighting in the retinula cells of the crayfish retina with both light and electron microscopic autoradiography. Times ranging from two minutes to seven days after an intracardiac injection were analyzed. Quantification of the electron microscopic autoradiograms revealed that labeling of the cytoplasm was greater than the rhabdome at 2, 5, and 30 minutes and reached a peak at 12 hours. The rhabdome showed increasing activity after 5, 30, and 60 minutes, also reaching a peak at 12 hours. Radioactive label in cytoplasmic multivesicular bodies was higher than activity measured in either the total cytoplasm or rhabdome at all times except two minutes. Two temporally different microvillar labeling patterns were seen under diurnal lighting conditions. (1) Microvilli forming the slightly enlarged distal tip of the rhabdome retained their radioactivity at 1, 3, and 7 days, when labeling of the rest of the rhabdome microvilli was decreasing. (2) In the remainder of the microvilli, labeling at 1 and 12 hours appeared as a gradient which declined toward the proximal end of the rhabdome. This gradient subsequently reversed itself, showing heavier proximal labeling at three days. In a second experiment, labeling patterns in light and dark adapted rhabdomes were compared. In the dark, a distinct gradient of activity was observed with radioactivity concentrated distally and declining toward the proximal end of the rhabdome. A more even distribution of label was present in the light adapted eye, but a slight distal-proximal gradient was still present. The dark adapted rhabdomes had more radioactivity per unit area than those exposed to light.


Subject(s)
Astacoidea/metabolism , Nerve Tissue Proteins/metabolism , Retina/metabolism , Adaptation, Ocular , Animals , Light , Nerve Tissue Proteins/biosynthesis , Time Factors
12.
Biotechniques ; 30(4): 852-6, 858, 860 passim, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11314268

ABSTRACT

We have demonstrated the isothermal in vitro amplification and multimerization of several different linear DNA targets using only two primers and the strongly strand-displacing exonuclease-negative Bst DNA polymerase. This reaction has been termed linear target isothermal multimerization and amplification (LIMA). LIMA has been compared with cascade rolling-circle amplification and has been found to be less sensitive but to yield similar variable-length multimeric dsDNA molecules. Products from several different LIMA reactions were characterized by restriction analysis and partial sequence determination. They were found to be multimers of subsets of the target sequence and were not purely primer derived. The sensitivities with respect to target concentration of several different LIMA reactions were determined, and they varied from 0.01 amol to 1 fmol. The sensitivity and specificity of LIMA were further tested using E. coli genomic DNA, and the selective amplification of a transposon fragment was demonstrated. A successful strategy for reducing LIMA-dependent background DNA synthesis in rolling-circle amplification embodiments was devised. This entailed the affinity purification of circular DNA templates before amplification.


Subject(s)
DNA Polymerase I/genetics , Geobacillus stearothermophilus/genetics , Nucleic Acid Amplification Techniques/methods , Base Sequence , Cloning, Molecular , DNA Primers , DNA, Bacterial/analysis , DNA, Circular/isolation & purification , Escherichia coli , Geobacillus stearothermophilus/enzymology , Indicators and Reagents , Molecular Sequence Data , Sensitivity and Specificity , Streptavidin
13.
Biotechniques ; 31(5): 1122-4, 1126, 1128-9, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11730018

ABSTRACT

Linear dsDNA composed of tandem repeats may be exponentially amplified by the strongly strand-displacing Bst DNA polymerase (large fragment) and two primers specific for opposite strands. When the repetitive DNA is derivedfrom rolling circle replication of a circular template, the reaction is termed cascade rolling circle amplification (CRCA). We have developed a variant of CRCA in which one primer is attached to the surface of a microwell and the other is labeled, thus enabling detection of amplified material using an ELISA-like protocol. The circular template is derived by annealing and ligation of a padlock on target DNA. It was found that there was good correlation between the synthesis of amplified material and signal. The specificity of the reaction with respect to single-nucleotide polymorphisms was investigated, and it was found that Bst DNA polymerase is prone to extension from primers with mismatched 3' ends. Reliable single nucleotide specificity was only obtained when pre-synthesized amplified material was interrogated by competitive primer extension.


Subject(s)
DNA Primers/genetics , DNA-Directed DNA Polymerase/genetics , Nucleic Acid Amplification Techniques , Polymorphism, Single Nucleotide , Sensitivity and Specificity
14.
Br J Pharmacol ; 126(4): 849-58, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10193764

ABSTRACT

1. This study investigates the effects of two agonists of the prostanoid EP3-receptor (M&B 28767 and GR 63799X) on the infarct size caused by regional myocardial ischaemia and reperfusion in the anaesthetized rat. 2. One hundred and sixty-seven, male Wistar rats were anaesthetized (thiopentone, 120 mg kg(-1) i.p.), ventilated (8-10 ml kg(-1), 70 strokes min(-1), inspiratory oxygen concentration: 30%; PEEP: 1-2 mmHg) and subjected to occlusion of the left anterior descending coronary artery (LAD, for 7.5, 15, 25, 35, 45 or 60 min) followed by reperfusion (2 h). Infarct size was determined by staining of viable myocardium with a tetrazolium stain (NBT), histological evaluation by light and electron microscopy and determination of the plasma levels of cardiac troponin T. 3. M&B 28767 (0.5 microg kg(-1) min(-1), i.v., n=7) or GR 63799X (3 microg kg(-1) min(-1), i.v., n=7) caused significant reductions in infarct size from 60+/-3% (25 min ischaemia and 2 h reperfusion; saline-control, n=8) to 39+/-6 and 38+/-4% of the area at risk, without causing a significant fall in blood pressure. Pretreatment of rats with 5-hydroxydecanoate (5-HD), an inhibitor of ATP-sensitive potassium channels, attenuated the cardioprotective effects of both EP3-receptor agonists. The reduction in infarct size afforded by M&B 28767 was also abolished by glibenclamide and the protein kinase C (PKC) inhibitors staurosporine and chelerythrine. 4. Thus, M&B 28767 and GR 63799X reduce myocardial infarct size in the rat by a mechanism(s) which involves the activation of PKC and the opening of ATP-sensitive potassium channels.


Subject(s)
Alprostadil/analogs & derivatives , Myocardial Infarction/drug therapy , Myocardial Ischemia/drug therapy , Prostaglandins E, Synthetic/pharmacology , Receptors, Prostaglandin E/agonists , Alprostadil/pharmacology , Anesthesia , Animals , Hemodynamics/drug effects , Male , Myocardial Reperfusion , Potassium Channels/physiology , Protein Kinase C/antagonists & inhibitors , Protein Kinase C/physiology , Rats , Rats, Wistar , Troponin T/blood
15.
Br J Pharmacol ; 128(5): 945-52, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10556930

ABSTRACT

1 This study investigated the effects of soluble complement receptor type 1 (sCR1) or sCR1sLex, agents which function as a complement inhibitor or as a combined complement inhibitor and selectin adhesion molecule antagonist, respectively, on the infarct size and cardiac troponin T (cTnT) release caused by regional myocardial ischaemia and reperfusion in the rat. 2 Eighty-two, male Wistar rats were subjected to 30 min occlusion of the left anterior descending coronary artery (LAD) followed by 2 h of reperfusion. Haemodynamic parameters were continuously recorded and at the end of the experiments infarct size (with p-nitro-blue tetrazolium) and cTnT release were determined. 3 Infusion of sCR1 (1, 5 or 15 mg kg-1, each n=7) or sCR1sLe(x) (1, 5 or 15 mg kg-1, n=7, 13 or 13, respectively) 5 min prior to LAD-reperfusion caused a reduction in infarct size from 59+/-2% (PBS - control, n=12) to 46+/-6%, 25+/-9% and 37+/-6% or 42+/-6%, 35+/-6% and 35+/-4%, respectively. 4 Infusion of sCR1 (15 mg kg-1, n=5) or sCR1sLe(x) (15 mg kg-1, n=5) also reduces the myocardial TnT release from 80+/-20 ng ml-1 (control) to 13+/-7 or 4+/-1 ng ml-1, respectively. 5 Thus, sCR1 or sCRsLe(x) significantly reduce infarct size and cardiac TnT release caused by 30 min of regional myocardial ischaemia and 2 h of reperfusion in the rat. The mechanisms of the cardioprotective effects of sCR1 or sCR1sLe(x) are not entirely clear, but may be due complement inhibition and/or prevention of the adhesion and activation of neutrophils.


Subject(s)
Cardiovascular Agents/pharmacology , Myocardial Infarction/pathology , Oligosaccharides/pharmacology , Receptors, Complement/chemistry , Animals , Blood Pressure/drug effects , Blood Pressure/physiology , Glycosylation , Heart Rate/drug effects , Heart Rate/physiology , Hemodynamics/drug effects , Male , Monocytes/physiology , Myocardial Ischemia/pathology , Myocardium/cytology , Myocardium/metabolism , Rats , Rats, Wistar , Recombinant Proteins/pharmacology , Sialyl Lewis X Antigen , Troponin T/blood
16.
Intensive Care Med ; 17(1): 52-6, 1991.
Article in English | MEDLINE | ID: mdl-1645379

ABSTRACT

Despite the improvements in the development of dialyzer membranes with greater hemocompatibility, an activation of the coagulation system occurs when blood comes into contact with exogenous surfaces. The large number of heparin dosage regimens demonstrated the difficulty to adapt general therapeutic guidelines. Low molecular weight heparin (Fragmin) was administered as a single bolus dose for anticoagulation during 58 acute dialyses. Anti-Xa-activity, the plasma levels of the lysosomal elastase of the polymorphonuclear granulocytes ("PMN-elastase") and of the thrombin-antithrombin III-complex (TAT) were measured at hourly intervals. Therapeutic anti-Xa-levels did not show evidence of sufficient inhibition of thrombin formation. The PMN-elastase increased by 180 ng/ml 3 h after administration of the bolus dose, with no further increase occurring (plateau phase). This was considered to reflect adequate anticoagulative activity. Where anticoagulation was inadequate, the elastase values rose consistently. After 2 h the increase of the PMN-elastase showed that--and to what extent--coagulation had been activated. The determination of PMN-elastase, using the IMAC-principle, is a method which can be performed quickly with any conventional autoanalyzer. It makes it possible to monitor adequate anticoagulation, but PMN-elastase results must be proven during routine use before recommendation as a routine test.


Subject(s)
Acute Kidney Injury/blood , Antithrombin III/chemistry , Heparin, Low-Molecular-Weight/therapeutic use , Pancreatic Elastase/blood , Peptide Hydrolases/chemistry , Renal Dialysis/adverse effects , Thrombosis/blood , Acute Kidney Injury/drug therapy , Acute Kidney Injury/therapy , Aged , Female , Heparin, Low-Molecular-Weight/administration & dosage , Heparin, Low-Molecular-Weight/pharmacokinetics , Humans , Leukocyte Elastase , Male , Middle Aged , Thrombosis/drug therapy
17.
Arch Surg ; 126(12): 1510-3, 1991 Dec.
Article in English | MEDLINE | ID: mdl-1842181

ABSTRACT

We performed a retrospective review of 68 patients who underwent pelvic exenteration for colorectal adenocarcinoma. Forty-seven patients had surgery for primary disease and 21 for recurrence. Clinical recurrence developed in 30 (44%) of 68 patients overall. Of these, 17 (57%) developed locoregional disease only as their first recurrence. This included nine (56%) of 16 patients with primary disease and eight (57%) of 14 patients with recurrent disease. Clinical recurrence developed in 16 (34%) of 47 patients with primary disease and 14 (66%) of 21 patients with recurrent disease. The overall 5-year survival rates were 43% and 20%, respectively. We conclude that locoregional recurrence remains a significant problem for primary or recurrent colorectal carcinoma even after radical pelvic surgery.


Subject(s)
Adenocarcinoma/secondary , Adenocarcinoma/surgery , Colorectal Neoplasms/surgery , Pelvic Exenteration , Adenocarcinoma/mortality , Colorectal Neoplasms/mortality , Female , Humans , Male , Middle Aged , Neoplasm Recurrence, Local , Retrospective Studies , Survival Rate , Treatment Outcome
18.
Ann Thorac Surg ; 54(5): 898-901; discussion 902, 1992 Nov.
Article in English | MEDLINE | ID: mdl-1417282

ABSTRACT

Over a 4-year period, 25 patients with pulmonary complications of acquired immunodeficiency syndrome underwent open lung biopsy for diagnosis. Results of the biopsy led to a change in therapy in 15, and of this group, 8 patients improved clinically and were discharged. We believe that a select group of acquired immunodeficiency syndrome patients with pulmonary disease will benefit from open lung biopsy. Our indications for open lung biopsy are (1) a nondiagnostic bronchoscopy, (2) failed medical therapy after a diagnostic bronchoscopy, (3) failed empiric medical therapy after a nondiagnostic bronchoscopy or after a second nondiagnostic bronchoscopy, and (4) when any of the forementioned are accompanied with a worsening chest roentgenogram. Patients with acquired immunodeficiency syndrome who have a deteriorating respiratory status or require mechanical ventilation should not undergo open lung biopsy.


Subject(s)
Acquired Immunodeficiency Syndrome/complications , Biopsy , Lung Diseases/complications , Lung Diseases/diagnosis , Lung/pathology , Adult , Biopsy/adverse effects , Humans , Lung Diseases/therapy , Male
19.
Ann Thorac Surg ; 65(3): 667-73, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9527193

ABSTRACT

BACKGROUND: The antifibrinolytic efficacy of a high-dose regimen of epsilon-aminocaproic acid (epsilon-ACA) was compared with aprotinin in first-time coronary operations. METHODS: In a prospective, double-blinded, randomized study, 20 patients received high-dose epsilon-ACA (10 g both as a loading and cardiopulmonary bypass priming dose, 2.5 g/h until 4 hours after protamine), and another 20 patients received aprotinin (2 x 10(6) KIU [280 mg] for loading and priming, 0.5 x 10(6) KIU/h [70 mg/h]). Ten untreated patients served as controls. RESULTS: Both agents reduced postoperative levels of thrombin/antithrombin III complexes, D-dimers, fibrin degradation products, free plasma hemoglobin (epsilon-ACA versus aprotinin, p = not significant; p < 0.05 versus controls), and amount of retransfused autologous blood (p < 0.001). Epsilon-ACA increased, aprotinin suppressed antiplasmin-plasmin complex generation (epsilon-ACA versus controls, p < 0.02; epsilon-ACA versus AP, p < 0.0001). For 4 hours after discontinuation, more chest drainage occurred with epsilon-ACA than aprotinin (137 +/- 90 mL versus 62 +/- 29 mL; means +/- standard deviation; p < 0.02). Cumulative 12-hour drainage was similar for aprotinin (391 +/- 220 mL) and epsilon-ACA (582 +/- 274 mL), but higher without inhibitor (1,091 +/- 541 mL; p < 0.001 versus drugs). Postoperatively, aprotinin was associated with the lowest autologous retransfusion incidence and highest hematocrits (p < 0.01 versus epsilon-ACA). Homologous transfusion exposures did not differ. CONCLUSIONS: In first-time coronary operations, higher postoperative hematocrit and less shed blood retransfusion constitute only subtle advantages of aprotinin over high-dose epsilon-ACA.


Subject(s)
Aminocaproic Acid/administration & dosage , Antifibrinolytic Agents/administration & dosage , Aprotinin/administration & dosage , Cardiopulmonary Bypass , Hemostatics/administration & dosage , Myocardial Revascularization , Aminocaproic Acid/adverse effects , Antifibrinolytic Agents/adverse effects , Aprotinin/adverse effects , Blood Coagulation/drug effects , Blood Transfusion , Blood Transfusion, Autologous , Double-Blind Method , Fibrinolysis/drug effects , Hematocrit , Hemostatics/adverse effects , Humans , Prospective Studies
20.
Thromb Res ; 98(6): 473-83, 2000 Jun 15.
Article in English | MEDLINE | ID: mdl-10899346

ABSTRACT

In 234 trauma surgery patients, thrombosis prophylaxis with Nadroparin-Calcium low-molecular-weight heparin (LMWH) was adjusted according to levels of D-Dimer. Basic prophylaxis was 2,850 IU per day. If D-Dimer concentrations rose above 2 mg/L after the fourth postoperative (p.o.) day, LMWH was administered twice a day. Color Doppler ultrasound was performed between the fifth and seventh p.o. days. Patients were divided into a high-risk (group 1: hip, femur, or knee replacement surgery, n=102) and a moderate-risk group (group 2: other surgery of the knee, tibia, fibula, or foot, n=132). Group 1 showed significantly higher D-Dimer levels than group 2 (p<0.001). Measurement of D-Dimer on days 2 and 4 p.o. showed a sensitivity of 100% and a specificity of 72.8% in identifying patients at risk (i.e., D-Dimer>2 mg/L after day 4 p.o.). The overall deep vein thrombosis (DVT) rate in group 1 was 3.9%, and the rate of proximal DVT was 1.96%. In group 2, one distal DVT (0.8%) occurred. The results show that D-Dimer is a useful marker to monitor p.o. coagulation activation and to manage LMWH prophylaxis in trauma surgery patients.


Subject(s)
Fibrin Fibrinogen Degradation Products/metabolism , Venous Thrombosis/prevention & control , Wounds and Injuries/drug therapy , Adult , Aged , Aged, 80 and over , Antifibrinolytic Agents/blood , Antithrombin III/metabolism , Biomarkers/blood , Female , Fractures, Bone/complications , Fractures, Bone/surgery , Humans , Leg Injuries/complications , Male , Middle Aged , Nadroparin/administration & dosage , Peptide Hydrolases/metabolism , Risk Factors , Sensitivity and Specificity , Time Factors , Venous Thrombosis/blood , Venous Thrombosis/drug therapy , Wounds and Injuries/complications , Wounds and Injuries/surgery
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