[Surgical management of dural arteriovenous fistulae in six patients]. / Manejo quirúrgico de las malformaciones arteriovenosas durales craneales. Serie de seis casos.

OBJECTIVES: In this article, we describe our experience in surgical management of dural arteriovenous fistulae (dAVF). MATERIALS AND METHODS: From August 2001 to February 2006 a total of six patients, were admitted at our hospital, 2 women and 4 men with ages between 40 and 68 years. RESULTS: Four of the six cases were entered through the service of Emergency Service by neurological deficit (in two cases) or decrease in the level of consciousness (in two patients); the remaining two patients were referred by lengthy headache and alterations on neuroimaging studies suggestive of dAVF. All of them showed dAVF in different locations which were treated successfully with surgery after angiographic studies. CONCLUSION: Although multiple therapeutic options are available, surgery is the treatment of choice in dAVF which shows aggressive clinical course, especially intracranial hemorrhage.

Manejo quirúrgico de las malformaciones arteriovenosas durales craneales. Serie de seis casos / Surgical management of dural arteriovenous fistulae in six patients

Objetivos. En este artículo describimos la experiencia quirúrgica de nuestro centro en el manejo quirúrgico de las malformaciones arteriovenosas duralesintracraneales (MAVd´s).Material y métodos. Presentamos una serie de seis casos, dos mujeres y cuatro hombres, con edades comprendidas entre 40 y 68 años, en el periodo que transcurre entre los años 2001 y 2006, en el Hospital Clínico San Carlos de Madrid. Resultados. Cuatro de los seis casos fueron ingresados a través del servicio de Urgencias por clínica deficitaria (en dos casos) o disminución del nivel de conciencia (en dos pacientes); los dos restantes fueron remitidos desde consultas externas por cefalea de larga evolución y alteraciones en el estudio de neuroimagen sugerentes de FAVd o MAVd. En todos ellos el tratamiento quirúrgico fue definitivo. Conclusiones. A pesar las múltiples opciones terapéuticas, la cirugía es de elección en MAVd que presenta especial tendencia a comportarse de forma agresiva; fundamentalmente con riesgo de hemorragia intracraneal

Objetives. In this article, we describe our experience in surgical management of dural arteriovenous fistulae (dAVF).Materials and methods. From Agust 2001 to Febrery2006 a total of six patients, were admitted at our hospital, with ages between 40 and 68 years. Results. Four of the six cases were entered through the service of Emergency Service by neurological defecit (in two cases) or decrease in the level of consciousness(in two patients); the remaining two patients were refered by lengthy headache and alterations on neuroimagen studies suggestive of dAVF. All of them showed dAVF in different locations which were treated successfully with surgery of the unique mortality of treatment after angiographical studies. Conclusion. Although multiple therapeutic option sare avaible, surgery is in dAVF which shows aggressive clinical course, especially intracranial hemorrhage

A comparison between capillary and venous blood international normalized ratio determinations in a portable prothrombin time device.

The CoaguChek PT system is a portable point-of-care device for prothrombin time testing that can be used with capillary and venous whole blood. This system had been calibrated by the manufacturer in terms of the international normalized ratio (INR) for monitoring oral anticoagulant therapy. The purpose of the present study was to compare capillary blood with venous blood INRs from healthy volunteers and patients treated with oral anticoagulants using the same CoaguChek PT system. Two different CoaguChek PT strip formulations [international sensitivity index (ISI), 1.5 and 1.1] were used in separate test series. The differences between capillary and venous blood INRs were statistically significant (P < 0.001) but the magnitude of the differences was small. The mean relative deviations of the INR were 5.8 and 2.8% for the strips with ISI 1.5 and 1.1, respectively. These deviations are clinically acceptable. It is concluded that capillary blood can be replaced by venous blood for the calibration of the CoaguChek PT system.

Effect of plasma pooling on the International Sensitivity Index of prothrombin time systems.

Guidelines set by the World Health Organization (WHO) state that in order to calibrate a prothrombin time system for International Sensitivity Index (ISI), freshly prepared specimens from 20 normal individuals and 60 patients receiving coumarin are required. These numbers are required to obtain a precise value of the calibration line slope when there is considerable scatter of individual data about the regression line. The scatter can be reduced by pooling individual plasma samples. In the present study, four pooled plasmas were prepared, one from 20 normal individuals and three from three groups of 30 patients receiving treatment with long-term oral anticoagulants. Prothrombin times were determined with four thromboplastins, HepatoQuick (rabbit thromboplastin combined with adsorbed plasma), Recombiplastin (recombinant human thromboplastin), Thromborel-S (human placenta), and Thromboplastin-C Plus (rabbit brain). Calibration line slopes were calculated for the six possible combinations of thromboplastins using the set of all individual plasma samples and the set of four pooled plasmas. In most comparisons, the WHO calibration model was appropriate, i.e. the line calculated for the patients' samples passed through the mean of the normals. The calibration line slopes obtained with the set of four pooled plasmas did not differ by more than 5% from the corresponding slopes calculated with the original individual plasmas. For some combinations of thromboplastins non-linear relations were observed both with the individual plasmas and with the pooled plasmas. We conclude that pooling individual plasmas does not significantly change the calibration relation between prothrombin times determined with the original individual plasmas. Freshly pooled plasmas can be used to determine the ISI of prothrombin time systems with an acceptable degree of precision.

Treatment of humoral rejection after heart transplantation.

BACKGROUND: Until a few years ago, the incidence of humoral rejection after heart transplantation was underestimated. These episodes were frequently very aggressive and often fatal, because the maintenance and emergency immunosuppression available at the time only inadequately covered the humoral branch of the immune response. In spite of individual case reports, the effects of blood purification procedures or cyclophosphamide in this situation can only be insufficiently estimated. METHODS: To evaluate this therapy concept, 20 dog-lymphocyte-antigen-matched dogs underwent heterotopic neck-heart transplantation. Fourteen dogs underwent transplantation after having been previously sensitized through multiple skin transplantations, 6 dogs were not sensitized (control). The animals received an induction with 3x 250 mg prednisolone, as well as triple immunosuppression (cyclosporine, azathioprine, and cortisone). Biopsy (light microscopy, immunofluorescence), intramyocardial voltage, electric myocardial impedance (>200 kHz, <10 kHz), and echocardiographic (left ventricular wall thickness, diastolic relaxation velocity) examinations were performed daily to monitor rejection. Rejection therapy was continued for 3 days according to the following regimen: apheresis, cortisone boluses (CB), and cyclophosphamide in group A1 (n = 4), apheresis and CB without cyclophosphamide in group A2 (n = 4), and CB only in group C (n = 6). The subsequent course under triple immunosuppression was then observed. RESULTS: In the sensitized animals the onset of severe humoral rejection on the fifth day deteriorated cardiac function down to 75% (70% to 80%) of the initial values. In groups A1 and A2, apheresis resulted in recovery to near-control values (89% to 94%) within two hours, and indeed to complete recovery (97% to 101%) after the second apheresis, that is, within 1 day. In group C recovery was delayed (2 days) and incomplete (84% to 91 %). After therapy was discontinued, rejection-related functional deterioration recurred immediately in group C, and from 2 to 3 days after apheresis, regardless of whether cyclophosphamide therapy was performed (group A1) or not (group A2). In the control group all animals showed a rejection-free posttransplantation course. CONCLUSIONS: By diluting inflammatory mediators, apheresis leads to a rapid improvement in cardiac function during severe humoral rejection after head transplantation. Neither apheresis nor cyclophosphamide therapy are able to have an immediate positive influence on the activation of the immune cascade and to prevent an ongoing rejection.

Influence of plasma volumetric errors on the prothrombin time ratio and International Sensitivity Index.

The International Sensitivity Index (ISI) for prothrombin time systems depends on the thromboplastin manufacturer's recommended method for use. The purpose of the present study was to investigate the influence of small deviations from the recommended sample volume on the prothrombin time ratio and ISI. Four commercial reagents were studied; three with low ISI and one with high ISI. The effects of volumetric errors on the ISI were used to assess the associated effects on the International Normalized Ratio (INR). The effect of 10% volume error on the INR was not greater than 5%. The effects with the three low-ISI reagents were slightly greater than those with the high-ISI reagent. It is recommended that each laboratory should check the volumes of sample and reagent used for the prothrombin time test.

Accelerated degradation test of lyophilized recombinant tissue factor-liposome preparations.

Accelerated degradation experiments were performed to assess the heat stability of lyophilized recombinant tissue factor-liposome preparations from two different manufacturers. When stored at 4 degrees C, these preparations did not show a significant change of the prothrombin time (PT). Two preparations (coded rTF-2 and rTF-a) showed a progressive prolongation of the PT on storage at 30 degrees C, 37 degrees C, and 44 degrees C. The third preparation showed an initial decrease of the PT at 37 degrees C and 44 degrees C followed by a progressive prolongation. Although none of the three preparations was absolutely stable at 30 degrees C, 37 degrees C and 44 degrees C, rTF-2 had the advantage that its PT-ratio (and hence its International Sensitivity Index) did not change under the conditions used in this study. The PT-ratio with a reference material for rabbit brain tissue factor (CRM149S) stored under similar conditions, did not change either.

Detection of inhibition of HIV-1 protease activity by an enzyme-linked immunosorbent assay (ELISA).

An ELISA is described for the detection of HIV-1 protease activity using an immobilized gag-related polyprotein as substrate. Proteolytic activity was demonstrated with either bacterial lysates expressing HIV-1 protease or purified protease. No cleavage was observed with a protein preparation from control bacteria not expressing HIV-1 protease. Under these conditions the aspartyl-type protease inhibitor, pepstatin A, was found to inhibit HIV-1 protease cleavage by > 90% at a concentration of 0.1 mM. This assay may be a useful tool for the study of both synthetic and natural inhibitors of HIV-1 protease.

[Biofreezer BF 80--a universally employed apparatus in preservation at very low temperatures]. / Biofreezer BF 80--eine universell einsetzbare Tieftemperaturkonservierungsapparatur.

A computer-controlled freezing apparatus is described which uses liquid nitrogen (LN2) as coolant. The freezing equipment BF 80 consists of a big cryochamber (volume 24 l), a LN2 tank and a computer for the control of the freezing procedure. The biofreezer functions in the range from 40 to -180 degrees C. A complete cooling curve can be composed of up 15 linear segments with freezing rates between 0 and 45 K.min-1. In the computer up to 80 different freezing curves can be stored and activated by simple operations. The reliability of the biofreezer BF 80 was successfully tested for the cryopreservation of lymphocytes.

[Immunochemical determination of human thiol protein disulfide oxidoreductase in cell and tissue homogenates by competitive EIA]. / Immunochemische Bestimmung der humanen Thiol-Proteindisulfid-Oxidoreduktase in Zell- und Gewebshomogenaten mit Hilfe eines kompetitiven EIA.

Different monospecific antisera against thiol-protein disulfide oxidoreductase (TPO, EC 1.8.4.2, protein-disulfide isomerase, EC 5.3.4.1) were raised in rabbits by immunization with purified human TPO and characterized by means of Laurell and immunoblot techniques. A competitive anti-TPO-EIA with insolubilized TPO has been used to determine this enzyme in cells and tissue homogenates. The assay shows a sensitivity of 1.2 ng/ml and a specificity of about 99%. The TPO content in relation to the total protein was found to be: in pancreas 0.65%, liver 0.45%, spleen 0.12%, placenta 0.16%, tonsils 0.06% and lymph nodes 0.03%.

[Controlled study of the effect of sports training on cardiopulmonary functions in asthmatic children and adolescents]. / Kontrollierte Untersuchung über die Wirkung sportlichen Trainings auf kardiopulmonale Funktionen bei asthmatischen Kindern und Jugendlichen.

The influence of physical training on the cardiopulmonary system and on lung function of asthmatic children was determined in a controlled study. The children were all indoor patients of the Hochgebirgsklinik Davos, Switzerland. 36 children at the age of 10 to 16 years entered the study. They were placed into either a "free running group", a "swimming group" or a "control group." The children of the training groups underwent a training of at least 10 units of 30 minutes each in 3 weeks. The control group did not participate in any regular physical training. Heart rate was measured before and after a bicycle ergometer exercise of 5 minutes at 2.5 watts/kg body weight. This was repeated at the end of the study. In the "free running group" a significant decrease of the heart rate at rest (p less than 0.05) and at the end of bicycle ergometer exercise (p less than 0.01) could be seen. In the "swimming group" the decrease of the latter was significant (p less than 0.05). In both groups an increase in work tolerance could be demonstrated, but not in the "control group." In all three groups an improvement of lung function (IVC, FEV1) was found, but it was not significant in any of the groups. The small improvement might be due to a reduction in allergen exposure and better medical treatment. The study confirms the possibility of physical training of children with asthma even if exercise-induced asthmatic signs and symptoms are present.

[Determination of cellular and humoral parameters of fatty liver]. / Untersuchungen von zellulären und humoralen Parametern bei Patienten mit Fettleber.

Cellular and humoral immunological parameters were examined in mononuclear cells from peripheral blood of patients with alcoholic and nonalcoholic steatosis hepatis. The ratio of T4 and T8 positive lymphocytes and the number of monocytes of these patients were in the normal range. The percentage of NK-cells, B-lymphocytes and DR-antigen-positive cells was increased.

[Fc-IgG and Fc-IgM receptor-carrying lymphocytes in human blood. Optimization of determining T(M) lymphocytes]. / Fc-IgG- und Fc-IgM-Rezeptor tragende Lymphozyten im menschlichen Blut. Optimierung der Bestimmung der TM-Lymphozyten.

Several methods for enumeration of Fc receptor bearing T lymphocytes and mononuclear cells from human peripheral blood were compared. The detection of Fc receptors is based on the formation of EA rosettes by using bovine erythrocytes and purified rabbit IgG or IgM antibodies. As alternative method the mixed rosette assay (EA rosettes plus sheep erythrocyte rosettes) (3) was applied for determining TG lymphocytes without the need of T cell separation. Independent of the method used for T cell separation (preparative rosetting with sheep erythrocytes stabilized by AET or HSA) the number of TG and TM lymphocytes was found to be identical. TG values obtained by use of the mixed rosette assay were significant lower (10 +/- 2%) than those obtained with the classical test (18 +/- 5%) (EA rosettes after T cell separation). Obviously this difference is due to a contamination of T lymphocyte preparations by non-T cells. On freshly isolated T lymphocytes without overnight culture we obtained 29% and 35%, respectively TM lymphocytes after separation of T cells using sheep erythrocyte rosettes stabilized with AET or HSA. The expression of FcIgM receptors was found to be strongly dependent on the composition and pH value of the culture medium. In the presence of human AB serum the maximum of FcIgM receptor expression on isolated T cells was obtained at pH 8.5. Under optimum conditions we found 63% and 66% respectively TM lymphocytes after T cell separation using AET or HSA stabilized sheep erythrocytes.

The thiol-proteindisulfide-oxidoreductase--a new marker enzyme of monocytes from peripheral blood.

Monocytes were enumerated by three different methods, cytochemical staining for alpha-naphthyl-acetate esterase-activity, immunofluorescence test using the monoclonal antibody BL-M/G and immunochemical staining for the enzyme thiol-proteindisulfide-oxidoreductase (TPO, EC 1.8.4.2) using a polyclonal rabbit anti-rat TPO immunoglobulin. For the comparison of these methods mononuclear cells from peripheral blood of healthy volunteers, patients with different diseases and adherent cell populations were tested. Statistical analysis showed no differences between the markers within these groups (H-test) and a significant correlation between the numbers of monocytes. TPO was found to be also valid for enumeration of monocytes obtained by adherence methods.