Coherent population trapping with controlled interparticle interactions

We investigate coherent population trapping in a strongly interacting ultracold Rydberg gas. Despite the strong van der Waals interactions and interparticle correlations, we observe the persistence of a resonance with subnatural linewidth at the single-particle resonance frequency as we tune the interaction strength. This narrow resonance cannot be understood within a mean-field description of the strong Rydberg-Rydberg interactions. Instead, a many-body density matrix approach, accounting for the dynamics of interparticle correlations, is shown to reproduce the observed spectral features.

Effects of a heparin-binding protein on blood coagulation and platelet function

The objective of this study was to characterize the heparin-binding properties of a protein secreted by mouse myeloma cells. The characterization was performed using clinical assays, such as heparin activity assays and heparin-induced thrombocytopenia (HIT) platelet activation assays. The tests were performed in the presence of heparin, low-molecular-weight heparins (LMWH), or heparinoids and either heparin-binding protein (HBP) or saline to determine whether the HBP affects the activity of heparins. The characterization of the HBP using heparin activity assays showed that the HBP shortened the prolonged clotting times of the activated partial thromboplastin time (aPTT) and thrombin clotting time induced by high concentrations of unfractionated heparin. The chromogenic assays for antithrombin (AT), thrombin inhibition, and factor Xa inhibition demonstrated that this effect is related to heparin concentrations below 0.5 IU/ml. The Heptest assay did not detect these differences. The HBP did not modify the anticoagulant effect of any LMWH or low- or high-sulfated glycosaminoglycans in the aPTT assay. Activation of donor platelets in the presence of unfractionated heparin, platelet factor 4 (PF4), and HIT-serum was not counteracted by the HBP in any of the assays. The characterization of the HBP using a PF4-enzyme-linked immunosorbent assay (ELISA) confirmed the lack of structural identity with PF4. However, the optical density data indicated that the protein structure may be similar to PF4 by binding to a PF4 antibody. These data suggest that the HBP isolated from mouse myeloma cells has a low affinity to heparin and interacts with the secondary binding site to AT and also perhaps to PF4.

Determination of serotonin release from platelets by enzyme immunoassay in the diagnosis of heparin-induced thrombocytopenia

[14C]-Serotonin release assay (14C-SRA) from platelets is considered to be the most sensitive test for laboratory confirmation of heparin-induced thrombocytopenia (HIT). This study compared 14C-SRA with an enzyme immunoassay (EIA) to determine the release of serotonin from platelets in the presence of heparin and serum from HIT patients. The normal range (median, 2.5 and 97.5 percentiles) of serotonin release from platelets in healthy subjects (n = 149) is 38 ng/ml (19 and 62) measured by EIA-SRA. Serum from HIT patients (n = 42) released 2548 ng/ml (244 and 7987) serotonin in the presence of 0.1 IU/ml heparin and 29 ng/ml (13 and 76) in the presence of 100 IU/ml heparin. One hundred per cent and 15% of HIT samples exhibited an elevated serotonin release from platelets in the presence of 0.1 IU/ml low molecular weight (LMW) heparin, 2100 ng/ml (869 and 5968), or danaparoid, 272 ng/ml (143 and 403), respectively. The sensitivity and specificity of the EIA-SRA was 100% and 97.4% and of the 14C-SRA 100% and 92.9% in HIT patients. No false-positive results were found in patients receiving heparin (n = 28), in patients with elevated levels of bilirubin (n = 5), in patients with antiphospholipid antibody syndrome (n = 10) or in non-HIT patients (n = 78) with both assays. The EIA technique to quantify serotonin release from platelets provides a reliable non-radioactive method to diagnose heparin-induced thrombocytopenia and to assess in vitro crossreactivity of low molecular weight heparins and heparinoid.

Long-term anticoagulation of outpatients with adverse events to oral anticoagulants using low-molecular-weight heparin

Bleeding complications are one of the major risks during oral anticoagulation. If further anticoagulation is indicated, low-molecular-weight heparin (LMWH) may offer an alternative treatment in those patients. In a prospective, nonrandomized study, 120 patients have been switched from oral anticoagulants to LMWH because of bleeding complications or other severe side effects during treatment with vitamin K antagonists. Indication for further anticoagulation was prophylaxis of recurrent thromboembolism, artificial heart valve replacement, atrial fibrillation with embolism and cardiomyopathy. The treatment period ranged from 2 months to 10.8 years. No fatal embolism occurred. One major but not severe episode of gastrointestinal bleeding occurred in a patient with an as yet unknown colon carcinoma. The cumulative treatment period amounts to 250 years. No drop in platelet count occurred in any patient. No other side effects were observed. LMWH was injected subcutaneously at doses ranging from 2500 to 15,000 anti-factor Xa units per day by the patient himself. The dose was adjusted on the basis of body weight, bleeding risk and thromboembolic risk. The results indicate that LMWH may be effectively and safely used as alternative anticoagulant regimen in patients with side effects or other complications on oral anticoagulants.

Resistance and vulnerability of crustaceans to cytolytic sea anemone toxins

Crustaceans (Mithraculus, Neopetrolisthes, Periclimenes, Stenorhynchus sp.) living in association with sea anemones, shore crabs (Metopograpsus oceanicus) and brine shrimps (Artemia salina) were found to be resistent to the exposure of cytolytic sea anemone toxins (up to 100 micrograms/ml) and to other membrane-active compounds such as gramicidin A and saponin. The gill filaments of the crustaceans were not affected, indicating that the chitin layer protects the epithelium from the action of the cytolytic toxins. However, crustaceans are highly susceptible to sea anemone toxins when injected parenterally.

[The Heidelberg trichina dispute. A parasitologic episode from the year 1840]

Since the initial zoological description of "Trichina spiralis" (later renamed "Trichinella spiralis") by Owen in 1835 several other scientists had observed trichinas in human muscles, when an inglorious dispute about priorities arose between the anatomists Kobelt and Bischoff at the Heidelberg University in 1840 because of one of those findings. The genesis of trichinosis was only to be explained in 1860 by Zenker, while Bischoff, who was among the leading 19th century embryologists, then still believed in a "generatio spontanea" as it has been described in the context of the chronological outline of the "trichina dispute".

[The effect of prophylactically administered n-acetylcysteine on clinical indicators for tissue oxygenation during hyperoxic ventilation in cardiac risk patients]

Hyperoxic ventilation, used to prevent hypoxia during potential periods of hypoventilation, has been reported to paradoxically decrease whole-body oxygen consumption (VO2). Reduction in nutritive blood flow due to oxygen radical production is one possible mechanism. We investigated whether pretreatment with the sulfhydryl group donor and O2 radical scavenger N-acetylcysteine (NAC) would preserve VO2 and other clinical indicators of tissue oxygenation in cardiac risk patients.

METHODS

Thirty patients, requiring hemodynamic monitoring (radial and pulmonary artery catheters) because of cardiac risk factors, were included in this randomized investigation. All patients exhibited stable clinical conditions (hemodynamics, body temperature, hemoglobin, F1O2 < 0.5). Cardiac output was determined by thermodilution and VO2 by cardiovascular Fick. After baseline measurements, patients randomly received either 150 mg kg-1 NAC (n = 15) or placebo (n = 15) in 250 ml 5% dextrose i.v. over a period of 30 min. Measurements were repeated 30 min after starting NAC or placebo infusion, 30 min after starting hyperoxia (F1O2 = 1.0), and 30 min after resetting the original F1O2.

RESULTS

There were no significant differences between groups in any of the measurements before treatment and after the return to baseline F1O2 at the end of the study, respectively. NAC, but not placebo infusion, caused a slight but not significant increase in cardiac index (CI), left ventricular stroke work index (LVSWI) and a decrease in systemic vascular resistance. Significant differences between groups during hyperoxia were: VO2 (NAC: 108 +/- 38 ml min-1m-2 vs placebo: 79 +/- 22 ml min-1m-2; P < or = 0.05), CI (NAC: 4.6 +/- 1.0 vs placebo: 3.7 +/- 1.11 min-1m-2; P < or = 0.05) and LVSWI (NAC: 47 +/- 12 vs placebo: 38 +/- 9; P < or = 0.05). The mean decrease of VO2 was 22% in the NAC group vs 47% in the placebo group (P < or = 0.05) and the mean difference between groups in venoarterial carbon dioxide gradient (PvaCO2) was 14% (P < or = 0.05). ST segment depression ( > 0.2 mV) was significantly less marked in the NAC group (NAC: -0.02 +/- 0.17 vs placebo: -0.23 +/- 0.15; P < or = 0.05).

CONCLUSIONS

NAC helped preserve VO2, oxygen delivery, CI, LVSWI and PvaCO2 during brief hyperoxia in cardiac risk patients. Clinical signs of myocardial ischemia did not occur such as ST-depression if patients were prophylactically treated with NAC. This suggests that pretreatment with NAC could be considered to attenuate impaired tissue oxygenation and to preserve myocardial performance better in cardiac risk patients during hyperoxia.

["...that subsequently homeopathy will become nowhere as common as in veterinary medicine"--the history of veterinary homeopathy in Germany]

The subject of this article is the historical development of veterinary homoeopathy in Germany until 1945. Turning away from drastic healing methods around 1800, Samuel Hahnemann started to develop his homoeopathic system which since the 1820ies was also applied in the treatment of animals, especially by laymen. The number of homoeopathically-oriented veterinarians remained small. This is also true for veterinary-homoeopathic articles claiming to be scientific while there was a considerable number of popular articles to be found. The professors of the veterinary teaching institutions rejected homoeopathy. At the end of the 19th century hardly anything was heard about veterinary homoeopathy, at least among the professionals. Scientific success in human and veterinary medicine pushed Hahnemann's teachings and those of his successors into the background. In the 1920ies homoeopathy was revived and the position of the renowned surgeon August Bier played an important part in that. Members of the "Studiengemeinschaft für tierärztliche Homöopathie" (Study Group for Veterinary Homoeopathy) which was founded in 1936 started to investigate the effects of homoeopathic drugs systematically. The war put an end to this project. The present situation of veterinary homoeopathy in Germany can be described as follows: Neither have allopathy and homoeopathy been united, as it had been predicted, nor has classical medicine accepted homoeopathy as a scientific discipline. Hahnemann's demand to make his teachings a part of the veterinary studies remains unfulfilled until today.

[History of veterinary medicine as a branch of learning--lessons and possibilities]

History of veterinary medicine--which has always been under-rated in the curricula--is the only discipline within the professional training of a veterinary surgeon which encompasses all subjects. It therefore has a uniting, virtually encyclopaedic, mediating function. The intention of a lecture must be to impart a historic view, to inspire the students to consider the responsibility which man has for animals, and to make them sensitive in their professional life for a critical reflection of the basic intellectual concepts of our time and our society beyond the limits of their knowledge of veterinary medicine. It is the veterinary surgeon's "professional culture"--and an essential part of it is the history of veterinary medicine and domestic animals--which demands that this permanent reflection be the basis for the meaningful work of a veterinary surgeon.

["With effort and much pain and an unspeakable, truly stupid patience." Theodor Ludwig Wilhelm von Bischoff (1807-1882) as an embryologist]

Theodor L. W. von Bischoff (1807-1882), who worked as an anatomist and physiologist in Heidelberg, Giessen and Munich, is among the most excellent embryologists of the 19th century. His work on the history of development of mammals and of man (1842), his finding proof of spontaneous periodic ovulation in mammals (1844), but above all his directive monographies on rabbits, dogs, guinea pigs and deer (1842-1854) provided the most comprehensive research into the history of the development of mammals which had been done so far. He was less successful, however, with his physiological research including a project on urea as a measure for metabolic activity (1853) which had been initiated by Justus Liebig. The same is true for his studies of the weight of the human brain and his comparative anatomical research into the anatomy of the skull and brain of primates, which had been his main interest since 1860. Bischoff, who had been raised to nobility for his merits, did not confine his activities to science, but engaged in questions of medical education and in the politics of his profession as a member of influential committees, fiercely opposing the admission of women to medical studies (1872).

[Humans and animals in the Middle Ages]

Some aspects of mediaeval human-animal relationships are presented. In addition to the role of the horse in Germanic cult sacrifices and the significance of domestic animals for the agricultural society of the Middle Ages, the attitude of Christianity to animals is also described. The integration of animals as religious symbolic figures in christian iconography and literature, trials against animals, the importance of tournament sports and hunting for the aristocracy are considered as well as the hippiatry of the court equerries, the equestrian medical practices of the blacksmiths, the possibilities of mediaeval veterinary medicine in the treatment of sick cattle and the use of animal products in medicine. Further sections are dedicated to the nutrition of the mediaeval population and related problems of hygiene, to the introduction of meat inspections and to parasitic disease from food.

Studies on the immunomodulatory effects of anthracycline antibiotics in mice: effects on immune responses and graft immunogenicity

The immunomodulatory effects of adriamycin, a clinically used tumor antibiotic, were studied. A 5-day course of adriamycin therapy in mice led to a suppression of the primary but not of the secondary humoral response to sheep erythrocytes without significant alterations in peripheral blood leukocyte subsets or lymphocyte subpopulations in the spleen. The delayed type hypersensitivity (DTH) response to ovalbumin or alloantigens was not inhibited. Adriamycin-treated spleen cells were unable to stimulate an allogeneic mixed leukocyte reaction, which shows that antigen presentation is inhibited by this drug. Adriamycin-treated murine skin grafts show a prolonged survival after allotransplantation despite their unimpaired ability to induce DTH. The possible cellular mechanisms of these effects and clinical relevance of adriamycin are discussed.

Biological activity and safety of the subcutaneous administration of high doses of low molecular weight heparin for 8 days in human volunteers

This study reports on the biological activity and safety of high dose low molecular weight (LMW) heparin therapy administered by two subcutaneous (s.c.) injections daily for 8 days in healthy human volunteers. Group 1 received 2 x 30 aPTT units LMW heparin/kg bodyweight, and group 2 received 2 x 50 aPTT units/kg per day. In group 1, activated partial thromboplastin time (aPTT) and thrombin clotting time (TCT) were uniformly prolonged by 3-5 sec 4 hrs after s.c. administration of heparin. Heptest coagulation time values were prolonged consistently as well by 57 sec on day 1 to 68 sec on day 8. Factor Xa inhibition measured by the S 2222 chromogenic substrate method continuously increased from 0.16 units/ml on day 1 to 0.28 units/ml on day 8. In group 2 prolongation of a aPTT and TCT values increased from 6 sec on day 1 to 15 sec on day 8 and of Heptest time from 70 sec on day 1 to 110 sec on day 8. S 2222 method showed factor Xa inhibitory activity which increased from 0.5 units/ml on day 1 to 0.75 units/ml on day 8. The clinical tolerance of the treatment was good. No changes in clinical chemistry parameters were detected, except for a reversible increase of serum transaminases. The coagulation studies demonstrate accumulation of LMW heparin when high doses are given twice daily. The half life of LMW heparin of factor Xa inhibition increases with increasing doses. Heptest coagulation values were prolonged to 4-6 times the normal values during administration of heparin.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative study on a new one-stage clotting assay for heparin and its low molecular weight derivatives

The effects of a normal and a low molecular weight (LMW) heparin fraction were compared by four coagulation methods. Plasma samples of patients were investigated who were treated with normal heparin or with a LMW heparin. The study was undertaken to analyze the interrelationship between the coagulation methods: Heptest, activated partial thromboplastin time, thrombin clotting time, and S 2222 chromogenic anti-factor Xa test. The results showed a high correlation between Heptest and S 2222 anti-factor Xa method for unfractionated and LMW heparin (r = 0.91 and 0.90). Comparing the coagulation times in seconds of Heptest and aPTT, the correlations were r = 0.56 (normal heparin) and 0.15 (LMW heparin). The correlation between the coagulation times of Heptest and thrombin clotting time were r = 0.65 and 0.25, respectively. The correlations between the coagulation methods were higher, when coagulation times rather than transformed values to units per liter of the Heptest and of the S 2222 anti-factor Xa method were employed. Furthermore, the data demonstrate a high sensitivity of the Heptest to conventional and LMW heparin, whereas activated partial thromboplastin time and thrombin clotting time are less sensitive to either heparin. For laboratory control of LMW heparin, Heptest and S 2222 chromogenic method are reliable tests. Therapeutic ranges will have to be established.

Monitoring of heparin and low molecular weight heparin with capillary and venous whole blood

A method for determination of antifactor Xa-like activity in capillary whole blood obtained from the fingertip is described, which employs the Heptest coagulation assay. Values obtained with capillary whole blood are compared to values of corresponding plasma and venous whole blood samples. Normal values in plasma, venous whole blood, and capillary blood from the fingertip were 17.1 +/- 2.1, 10.0 +/- 1.3 and 10.4 +/- 1.3 sec, respectively. The intraindividual coefficients of variations range from 0.4 to 1.8% in all assays. The day to day coefficient of variation of normal values ranged between 0.8 and 2.0% for all assays. The within assay coefficients of variation ranged from 3.0 to 7.7% for whole blood samples and from 1.5 to 2.2% for plasma samples after addition of no, 0.2 or 1.0 units of normal or LMW heparin to the samples. After administration of heparin or LMW heparin in healthy persons the coagulation values of the different coagulation assay systems displayed coefficients of correlation between r = 0.87 and r = 0.95. Correlation coefficients between the coagulation tests and the S 2222 chromogenic substrate method ranged from r = 0.77 to r = 0.92. In patients, who received LMW heparin for prophylaxis of thromboembolism the coagulation assay correlated between r = 0.78 and 0.92. The coagulation assays and the S 2222 method displayed coefficients of correlation between r = 0.74 and r = 0.83. The data indicate that Heptest sensitively measures antifactor Xa-like activity in capillary whole blood as well as venous whole blood samples containing low quantities of heparin or LMW heparin.

Effect of dried garlic on blood coagulation, fibrinolysis, platelet aggregation and serum cholesterol levels in patients with hyperlipoproteinemia

The effects of intake of dried garlic on blood coagulation, fibrinolysis, platelet aggregation, serum cholesterol levels, and blood pressure were studied in 20 patients with hyperlipoproteinemia over a period of four weeks. Fibrinogen and fibrinopeptide A significantly decreased by 10%. Streptokinase activated plasminogen and fibrinopeptide B beta 15-42 significantly increased by about 10%. Serum cholesterol levels significantly decreased by 10%. Systolic and diastolic blood pressure decreased. ADP and collagen induced platelet aggregation were not influenced.

[Neutralization of low molecular weight heparin Kabi 2165 by protamine chloride]

Low molecular weight (LMW) heparin Kabi 2165 possesses improved pharmacodynamic properties compared with conventional heparin. It is currently investigated in the prophylaxis of thromboembolism. The neutralization of Kabi 2165 by protamine chloride was analysed after i.v. injection of both the agent and the antidot in healthy persons. The anticoagulant effects of the LMW heparin on the activated partial thromboplastin time, thrombin, and thromboelastography are completely and immediately suppressed by protamine chloride. The inhibition of factor Xa is antagonized up to 50%-60%. The bleeding time remained unaffected. The data indicate that protamine chloride may be used in clinical situations as an antidot to the LMW heparin Kabi 2165. A rebound phenomenon of the anticoagulant effect does not occur.