Heparin excretion in intact and hepatectomized rats.

Metabolism and kinetics of 3H-heparin were compared in intact and hepatectomized rats. Rats were divided into three groups: 1) intact rats with biliary fistulas and cystostomies 2) intact rats with only cystostomies and 3) hepatectomized rats with cystostomies. Radioactivity in blood, bile and urine besides anticoagulant activity in blood and urine were examined. In addition, column chromatography of urine was used to isolate possible metabolites. Seventy percent and 80% of the radioactive dose was found in the urine of intact rats at 24 hr and 48 hr. Close to 5% of the radioactivity was found in bile or rats with a biliary fistula after 48 hr. The APTT declined to near normal values at 1 hr whether rats had a biliary fistula or not. In contrast, only 25% of the radioactivity could be exerted into the urine of hepatectomized rats in 24 hr; the APTT did not decline as fast and at 5 hr, it was still 100 seconds. Only one radioactive component could be isolated on chromatography from all urines of these animals and appears to be similar to the original heparin. Thus, the liver has no important role to play in regulating the anticoagulant effects and excretion of heparin.

Antithrombin III and Factor VIII in patients with neoplasms.

Possible increased activation of the coagulation pathway was measured in a group of patients with neoplastic diseases. In addition to standard tests, the thromboplastin generation test, thrombin generation test and immunologic and coagulant activities of both Factor VIII and antithrombin III were utilized in the evaluation. The correlation between immuno-Factor VIII (VIII-Ag) and its clotting activity (VIII-C1) was good (r = 0.83). In contrast, this was not the situation for antithrombin III-Ag and its clotting activity. Thromboplastin generation was accelerated in 60% and thrombin generation was accelerated in 40% of the patients. Fibrinogen was elevated in half the cases: in most of these patients, thrombin times were slightly prolonged. These results indicate that some patients who have cancer have abnormal clotting patterns and are often in a potentially hypercoagulable state that is reflected by the thromboplastin generation test, thrombin generation test, and high levels of Factor VIII (both VIII-Ag and VIII-C1).

Asbestos-related fibrin formation in human plasma.

This study was designed to test the hypothesis that asbestos is responsible for the activation of clotting, for the reduction in activity of clotting factors and for the formation of fibrin when human plasma is exposed to asbestos chrysotile fibers in vitro. The recalcification time was accelerated in the early phase and was found to be greatly prolonged at 24 hours. The activated partial thromboplastin time showed marked changes at 24 hours only. One group of clotting factors, consisting of factors V, IX and X, showed the greatest decrease in their plasmatic activity. The factors least changed were factors XII and VIII; the other clotting factors were found in between these groups. Histologic examination demonstrated fibrin fibers in close proximity to the asbestos. Thus, chrysotile asbestos fibers activate clotting with the subsequent decrease in activity of some coagulation factors resulting in the formation of fibrin.

Analytical metrological characterization of the three-parameter sine fit algorithm.

The three-parameter sine fit is a well known algorithm used in IEEE standard 1241-2000 for ADC characterization to estimate sine wave parameters from recorded data. An analytical metrological characterization of that algorithm is carried out in terms of its design parameters, namely the sampling rate and the number of samples. Optimal and sub-optimal parameters' sets are found. Focusing on the amplitude estimation, an approximated statistical characterization of the second order is given in the most general case of zero mean additive noise, whereas the exact probability density function is found for the optimal set of algorithm parameters in the case of additive white Gaussian noise. In this particular case, the frequency behavior of the algorithm is fully analyzed and the exact frequency response of the amplitude is also found. An approximated expression that is easier to use is then presented and discussed. Simulation results for a single set of parameters are presented in order to graphically illustrate the analytical results.

Upgrade of the resonance ionization laser ion source at ISOLDE on-line isotope separation facility: new lasers and new ion beams.

The resonance ionization laser ion source (RILIS) produces beams for the majority of experiments at the ISOLDE on-line isotope separator. A substantial improvement in RILIS performance has been achieved through a series of upgrade steps: replacement of the copper vapor lasers by a Nd:YAG laser; replacement of the old homemade dye lasers by new commercial dye lasers; installation of a complementary Ti:Sapphire laser system. The combined dye and Ti:Sapphire laser system with harmonics is capable of generating beams at any wavelength in the range of 210-950 nm. In total, isotopes of 31 different elements have been selectively laser-ionized and separated at ISOLDE, including recently developed beams of samarium, praseodymium, polonium, and astatine.

Gel chromatography of heparin.

It is assumed that heparin is a heterogeneous substance. In order to further investigate the purification of heparin, a column chromatographic technique for the fractionation of heparin is described using various diameters of bead form cross-linked dextran gels and an automated apparatus. It was observed that Sephadex G-50 resulted in the separation of three well formed peaks and provided superior resolution compared to all other gels. One of the peaks, representing 51% of the original material, possessed strong anticoagulant activity as measured by the recalcification time, partial thromboplastin time, thrombin time and the anti-Xa test. This peak also possessed strong metachromasia after electrophoresis as well as having a very potent anticoagulant effect in vivo. This technique may have a significant role in the purification of this agent from tissue sources.

Treatment of "intractable childhood epilepsy" with high doses of intravenous gamma-globulins.

The authors refer their experience in the treatment of intractable childhood epilepsies (18 cases) with intravenous gamma globulin. Seven patients showed great reduction or indeed disappearance of the seizures whereas modest improvement was observed in other 4 cases. A better organization of the EEG corresponded to this clinical improvement with a reduction or disappearance of paroxysmal anomalies, and also a better result in motor and cognitive capacities.

Fisher syndrome. An infantile case.

A case of acute onset of partial ophthalmoplegia, ataxia and areflexia in a child is described. This case closely resembles those described by Fisher (Fisher syndrome). Clinical data, also in relation to the few cases previously reported, are discussed.

Correlations between abnormalities on brain SPECT scan and interictal EEG-foci in children with 'intractable' partial epilepsy.

SPECT scanning with Tc99mHM-PAO was performed on 40 children with 'intractable' partial epilepsy; 27 patients had abnormalities on SPECT images consisting of areas of decreased cerebral blood flow. In 18 of these 27 subjects there was a good correlation between site of the abnormalities on SPECT scan and interictal EEG foci. 12 patients with regionally decreased CBF had also neuroimaging (C.T. and/or R.M.I.) abnormalities. The brain SPECT provides more precise detection of epileptogenic foci, when used to complement EEG, also in childhood-onset epilepsy.

Brain SPECT and migraine in childhood.

The recent development of SPECT has introduced a new procedure to evaluate neurological diseases. By mean of Tc99mHM-PAO we studied a group of 19 pediatric subjects (7 males and 12 females) with different form of migraine, within five days after the last headache attack. Postictally SPECT shows regionally decreased CBF in 3/4 of HM, in 5/6 of BAM, in 5/5 of CM and in 2/4 of M.

Levels of antithrombin III, alpha 2-macroglobulin, and alpha 1-antitrypsin in acute ischemic heart disease.

Since measurements of AT III and other possible coagulation inhibitors might provide an index of hypercoagulability, the goal was to measure over a 3-month period individual changes in blood levels of AT III, alpha 2-microglobulin, and alpha 1-antitrypsin in 51 patients with acute ischemic heart disease who were admitted to a Coronary Care Unit with the following diagnosis: unstable angina (26 patients), acute transmural myocardial infarction (20 patients), or subendocardial myocardial infarction (5 patients). Some patients received prophylactic antithrombotic therapy. AT III was measured by the von Kaulla, Owen, Thrombo-Screen, chromogenic, immunodiffusion, and immunoelectrophoretic methods. Alpha 2-macroglobulin and alpha 1-antitrypsin were measured by immunodiffusion. All inhibitors were measured on three different occasions: (1) on admission to hospital, (1) day of departure from hospital, and (3) at 3 months after hospitalization. Alpha 1-antitrypsin showed a significant increase compared to the control and remained elevated during the 3-month interval. Compared to normal control values, AT III was found to be significantly diminished when measured by one functional method (von Kaulla) in all three blood samples from patients with unstable angina and transmural myocardial infarction and by one immunological method (immunodiffusion) in patients with unstable angina, transmural myocardial infarction, and subendocardial myocardial infarction. Most methods determining functional AT III detected a significant increase 3 months after the acute ischemic episode; this rise was observed more often in patients with myocardial infarction than in those with unstable angina. Stepwise discriminant analysis separated the patients of the three groups. Subcutaneous heparin has no significant effect on AT III levels. Unexplained discrepancies still exist between the results obtained by various functional and immunological methods for determining AT III. It appears, however, that methods measuring functional AT III seem to be more suited than immunological methods to detect changes in AT III levels that might occur during and after an acute episode of ischemic heart disease.