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Biomedical subjects

D Paar

Publications and source records attributed to D Paar.

At least 37 records · Page 2Linked to original sources

A new method of veno-venous bypass during human orthotopic liver transplantation.

Veno-venous bypass is commonly used during orthotopic liver transplantation, but there is some controversy as to whether it contributes to a better outcome. Low shunt flows frequently reduce the efficacy of portofemoro-axillary systems and so a percutaneous cannulation technique for the subclavian and femoral vein with large bore catheters was developed in order to facilitate bypass management. This study reports the performance and complications of a portofemoro-subclavian bypass system during the anhepatic phase of human orthotopic liver transplantation in 85 patients. A percutaneous cannulation technique and two 7 mm (subclavian and femoral) catheters, inserted pre-operatively, were used in a pump driven portofemoro-subclavian bypass system. Coagulation profiles, shunt flows, haemodynamic parameters, and peri-operative complications associated with bypass were recorded for each patient. Percutaneous cannulation of the left femoral and subclavian vein was successful in 78 patients (91.8%). Mean femoro-subclavian shunt flow was 1.45 l.min-1 (SD 0.37), and mean portofemoro-subclavian flow was 4.28 l.min-1 (SD 1.03). Although oxygen delivery was not maintained at pre-shunt levels (559.7 (SD 147) vs 506 (SD 107) ml.min-1.m-2, p < 0.05) renal perfusion pressure stayed above 50 mmHg (during shunt it was 56 (SD 9) mmHg). One intra-operative air embolism was observed (1.2%), and in one patient a myocardial infarction occurred during the anhepatic phase; neither complication was considered to be related to the percutaneous cannulation technique. There were no bleeding complications. After operation, all chest X rays were normal and clinical examination revealed no adverse effects of portofemoro-subclavian bypass.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Basophilic leukocytes in hypothyroidism.

Since in the literature basophilia is frequently related to myxedema, we evaluated basophilic leukocytes in patients with hypothyroidism, applying routine techniques used in clinical laboratories. The study included normal persons, untreated patients with hypothyroidism, and euthyroid subjects with hyperlipidemia. The number of circulating basophils was determined by differential counts of Pappenheim stained blood smears. No difference in relative and total basophil counts was detected in patients with hypothyroidism as compared to healthy controls (1.0% and 58.1 basophils/microliters vs. 0.8% and 50.8 basophils/microliters, respectively). The percentage of basophils in myxedema associated with hypercholesterolemia amounted to 1.0%, their absolute number to 57.6/microliters; in hypothyroid patients presenting normal serum cholesterol levels, the relative and absolute numbers of basophilic leukocytes was not statistically different (0.83% and 61.1 basophils/microliters, respectively). We conclude that in patients with hypothyroidism the number of basophils is not statistically different from the values of basophils in healthy controls. Furthermore, the number of peripheral blood basophils in hypothyroidism is not related to the serum cholesterol level.

Adult↗

Hemostatic changes due to the venom gland extract of the red-necked keelback snake (Rhabdophis subminiatus).

After a bite by the aglyphous red-necked keelback snake Rhabdophis subminiatus a complete defibrinogenation syndrome with severe hemorrhagic diathesis developed in a 25-year-old man. In vitro studies showed that the venom gland extract of the snake contains a very active prothrombin (Factor II) activator. The thrombin generated is inhibited neither by antithrombin III nor the antithrombin-III-heparin complex. The venom gland extract stimulated also the tissue plasminogen activator; however, it did not cause direct activation of plasminogen, protein C, Factor X or direct degradation of fibrinogen.

Adult↗

[Thrombocytapheresis with the (Baxter) A 201 cell separator--initial data of biocompatibility].

The cell separator A 201 was a new platelet pheresis prototype designed to carry out a discontinuous apheresis while platelet-rich plasma (PRP) is sampled continuously. After donation, a platelet concentrate (PC) and a fresh frozen plasma was collected from the PRP by the plasma cell-C device. The PC contained 2.6 +/- 0.7 x 10(11) platelets with a leucocyte contamination of 3.9 +/- 3.9 x 10(8) and an erythrocyte contamination of 3.0 +/- 3.0 x 10(8). The fresh frozen plasma was nearly cell-free. Prior, during and after apheresis we analysed hemolysis and coagulation parameters. There was no evidence for hemolysis. The analysis of the coagulation factors and of the Thrombin-Antithrombin III-complex, however, gave a hint of an activation of coagulation.

Biocompatible Materials↗

Intraperitoneal heparin in peritoneal dialysis and its effect on fibrinopeptide A in plasma and dialysate.

In 6 patients on continuous ambulatory peritoneal dialysis we investigated the inhibition of intraperitoneal fibrin formation by heparin. A continuous addition of 500 U of heparin per liter dialysate was used for 52 h. In plasma no heparin activity could be detected, even 52 h after intraperitoneal administration of heparin. The fibrin formation was determined by fibrinopeptide A, a thrombin-induced split product of fibrinogen. In patients under regular continuous ambulatory peritoneal dialysis we determined the fibrinopeptide A concentrations in plasma. The values were comparable with the fibrinopeptide A concentrations measured in disseminated intravascular coagulopathy. They decreased during intraperitoneal administration of heparin from 63.2 +/- 11.8 to 4.9 +/- 1.7 ng/ml. The fibrinopeptide A concentration in the 4-hour intraperitoneal dialysate (155.8 +/- 15.7 ng/ml) decreased after heparin administration to 8.5 +/- 2.0 ng/ml and was always higher than in plasma. We conclude that 500 U heparin per liter dialysate prevents the intraperitoneal fibrin formation. The low antithrombin III concentration (0.44 +/- 0.13 mg/dl) in protein-poor dialysate seems to be sufficient to inhibit the thrombin activity after acceleration by heparin.

Ascitic Fluid↗

Reactogenicity and immunogenicity of a new recombinant yeast-derived hepatitis B vaccine.

Under randomized double-blind conditions, 220 medical students were vaccinated with either a 2.5, 5, 10, or 20 micrograms dose of a recombinant yeast-derived hepatitis B or a 20 micrograms dose of a plasma-derived vaccine. Vaccines were administered at months 0, 1, and 2. After 11 months, all vaccinees received a 20 micrograms booster dose of the recombinant vaccine. There were no significant differences in adverse reactions between the study groups. Induction of IgE antibodies to yeast was not observed. One month after the third vaccination, seroconversion rates reached 100% in all vaccines. Mean anti-HBs levels varied between 150 and 1470 IU/l after 3 vaccinations, with the lowest dose resulting in the lowest titres. Following the booster vaccination, dose-dependent effects were no longer observed. Anti-HBs concentrations were reanalyzed 29 and 36 months after the study had started. The data indicate that the recombinant hepatitis B vaccine is safe and immunogenic for use in man and comparable to the plasma-derived vaccine in terms of safety and efficacy.

Antibodies, Fungal↗

Adult respiratory distress syndrome as a specific manifestation of a general permeability defect in trauma patients.

To establish whether a general dysfunction, i.e., an increase in permeability, had occurred in 16 trauma patients (6 with adult respiratory distress syndrome [ARDS]), we measured beta 2-microglobulin (beta 2MG), myoglobin (MG), immunoglobulin G (IgG), and transferrin (TF) concentrations in bronchoalveolar lavage fluid (BAL), serum, and urine as well as extravascular lung water content (EVLW) over a period of 14 days. Our results show a positive correlation (p = 0.03) between increases of EVLW, reflecting lung edema, and beta 2MG concentrations in urine of all patients with ARDS, indicating systemically increased permeability. Generalized increase of permeability can also explain the elevation of MG urine concentrations (p = 0.03) together with an EVLW increase, and an increase of BAL protein concentrations (IgG, TF, p less than 0.01) in the early post-trauma phase during the first 48 h after admission. In contrast, commonly used kidney function tests remained unchanged over the time course of 14 days.

Adolescent↗

Lupus anticoagulant associated syndrome in benign and malignant systemic disease--analysis of ten observations.

The clinical and laboratory findings in seven female patients with primary autoimmune diseases, one female patient with lymphoplasmacytoid (LP) immunocytoma and IgM paraproteinemia, and two male patients with multiple myeloma are described. The common denominator in all patients was a lupus anticoagulant or a closely related coagulation disorder. Recurrent thrombosis was observed in six patients with autoimmune diseases and in two patients with malignant monoclonal gammopathies. Other clinical manifestations included cerebral disorders (four patients with autoimmune disease/two patients with monoclonal gammopathy), repeated obstetric complications (6/1), asymptomatic valvular heart disease (6/1), renal dysfunction (6/2), hepatic involvement (2/2), and arthropathy (2/0). Laboratory investigations revealed a biologic false-positive serological test for syphilis in six patients with autoimmune disease and one with monoclonal gammopathy, antinuclear antibodies (4/0), antibodies against DNA (4/1), and a positive direct Coombs test (3/1) which was accompanied by hemolytic anemia in two patients (1/1). Additionally slight leukocytopenia (2/1) and thrombocytopenia (6/2) were observed; abnormal bleeding was only seen in one patient with severe thrombocytopenia. Other complications characteristic of LP immunocytoma or multiple myeloma were missing. The obvious similarities between the patients with autoimmune diseases and the patients with malignant monoclonal gammopathies suggest analogous pathogenetic mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Spontaneous↗

Lupus anticoagulant associated syndrome in benign and malignant systemic disease.

A strong correlation exists between the presence of an in vitro plasma coagulation inhibitor, named "lupus anticoagulant", and a clinical syndrome of recurrent arterial and venous thromboses, neurological abnormalities, repeated obstetrical complications, thrombocytopenia, a biologic false-positive serological test for syphilis, and a variety of rarer manifestations. This syndrome has predominantly been observed in patients with autoimmune diseases, but it may be of similar importance in association with monoclonal gammopathies. As an introduction to a detailed analysis of ten observations which will also be published in this journal, this article reviews the clinical findings, the proposed pathogenetic mechanisms and the approaches to management of the lupus anticoagulant associated syndrome.

Autoantibodies↗

Multicentre dose range study of a yeast-derived hepatitis B vaccine.

Healthy young adult volunteers, 778 in number, without HBV markers were randomly distributed into groups and administered different lots of a yeast-derived hepatitis B vaccine (YDV) at different dose levels or a commercial plasma-derived vaccine (PDV), according to a 0, 1, 2, 12-month vaccination schedule. The YDV proved to be safe and well tolerated, even when partly purified lots were given. Reactions were mild and transient, comparable to those observed after PDV. One month after three YDV doses, 0-7% of subjects overall had failed to seroconvert; all those evaluated one month after the booster dose had seroconverted. No significant difference was found between the two vaccine types as far as seroconversion rates were concerned. Geometric mean anti-HBs levels following three vaccine doses were higher in seroconverters of the PDV groups. However, a booster dose of YDV resulted in high anti-HBs levels in all groups varying from 11,474 to 51,404 IU l-1 (purified YDV lot), 4915 to 18,832 IU l-1 (partly purified YDV lots) and 11,008 to 15,805 IU l-1 (PDV lots). Of seroconverters to the purified lots of YDV 93% attained 1000 IU l-1 after the booster dose, thus ensuring protection for a number of years. Dose-response studies provided a basis for the selection of 20 micrograms of highly purified YDV as the standard dose.

Adult↗

Effects of a recombinant yeast-derived hepatitis B vaccine in healthy adults.

Under randomized, double-blind conditions, 220 medical students were vaccinated with either a 2.5, 5, 10, or 20 micrograms dose of a recombinant yeast-derived hepatitis B or a 20 micrograms dose of a plasma-derived vaccine. Vaccines were administered at months 0, 1, and 2. After 11 months, all vaccinees received a 20 micrograms booster of the recombinant vaccine. There were no significant differences in adverse reactions between the study groups. Induction of IgE antibodies to yeast was not observed. One month after the third vaccination, seroconversion rates reached 100% in all vaccinees. Mean anti-HBs levels varied between 150 and 1470 IU/l after 3 vaccinations, with the lowest dose resulting in the lowest titres. Following the booster vaccination, dose-dependent effects were no longer observed. These data indicate that the recombinant hepatitis B vaccine is safe and immunogenic for use in man and comparable to the plasma-derived vaccine in terms of safety and efficacy.

Antigens↗

[Tonsillectomy in factor XII deficiency].

A case of tonsillectomy in a 22-year-old female patient suffering from isolated deficiency of factor XII is presented. The importance of close cooperation of surgeon and haemostaseologist is pointed out. Preoperative, intraoperative and postoperative precautions are discussed.

Adult↗

Intraperitoneal fibrin-formation and its inhibition in CAPD.

The intraperitoneal fibrin formation and its inhibition by intraperitoneal heparin (5000 U) was investigated in six patients on CAPD. The intraperitoneal heparin concentration decreased linearily from 1.78 U/ml to 1.13 U/ml during a 4-hour dwell time. The antithrombin III-concentration increased to 0.56 +/- 0.1 mg/dl, reaching 1.87% of normal plasma values. The antithrombin III-portion of total protein was 0.62% in plasma and 0.79% in dialysate. The fibrinopeptide A-concentration, a specific product of thrombin action on fibrinogen was 37.1 +/- 11.8 ng/ml in plasma (normal range: less than 2.5 ng/ml) and 153.4 +/- 16.8 ng/ml in dialysate during regular CAPD. After the addition of 5000 U heparin the fibrinopeptide A-concentration in dialysate decreased to 11.6 +/- 2.6 ng/ml during a 4-hour dwell time. In vitro experiments showed no remarkable inhibition of fibrin formation by heparin without antithrombin III in dialysate. We suggest that the fibrinopeptide A is produced intraperitoneally and the antithrombin III-concentration in dialysate is sufficient to inhibit the fibrin formation after acceleration by heparin.

Antithrombin III↗