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Biomedical subjects

H Riess

Publications and source records attributed to H Riess.

At least 109 records · Page 6Linked to original sources
PubMed1993

Influence of prostaglandin E1 infusion on hemostasis in orthotopic liver transplantation.

In the control group, a significant decrease in platelet aggregability could be demonstrated after reperfusion. This was paralleled by a decrease in platelet counts. When PGE1 was infused during OLT, the post-reperfusional decreases in platelet aggregability and platelet counts in the control group could be prevented. Furthermore, our investigation demonstrated that PGE1 infusion led to higher t-PA activity during the anhepatic phase. This was paralleled and followed by lower alpha 2AP levels at the end of the anhepatic phase and after reperfusion. The higher t-PA levels in the PG group did not result in clinical signs of hyperfibrinolysis during OLT. The aprotinin administration in both groups is most certainly responsible for the absence of hyperfibrinolytic signs in the TEG and the low overall requirement for transfusions, explaining the comparable transfusion rate in the two groups (Fig. 5). Further investigations involving more patients are required to evaluate the clinical effect of PGE1 therapy.

Alprostadil↗
PubMed1993

Changes in urokinase-type plasminogen activator in orthotopic liver transplantation.

Elevated levels of u-PA Ag and scu-PA preoperatively and before revascularization of the graft are explained by an impaired clearance function by the diseased liver. They are parallel preoperatively and in the beginning of OLT by increased tcu-PA activity. This may reflect a role of the intrinsic fibrinolytic system in the "hyperfibrinolytic state" observed in patients with end stage liver disease. u-PA Ag and scu-PA normalize following reperfusion. The increase in tcu-PA observed during the anhepatic phase coincided with greatly increased fibrinolysis, as demonstrated by thrombelastography. This indicates that u-PA seems to be involved in the development of fibrinolysis during OLT. It had been demonstrated in previous investigations that a significant increase of t-PA activity was seen in the late anhepatic phase leading to an elevated plasmin generation. Since plasmin is a major activator of scu-PA, a t-PA mediated scu-PA activation would explain the concomitant increase in both plasminogen activators.

Aprotinin↗
PubMed1993

Evidence that intraoperative prostaglandin E1 infusion reduces impaired platelet aggregation after reperfusion in orthotopic liver transplantation.

Recent investigations measuring platelet aggregation during 10 orthotopic liver transplantations showed a significant decrease in platelet aggregation immediately after reperfusion and in the perfusate. As prostaglandin E1 has been shown to exhibit a beneficial effect in the treatment of ischemic injury of the liver, we investigated in a prospective, randomized, and open study the effect of PGE1 infusion during OLT on platelet function. Ten patients were randomized to receive a continuous PGE1 infusion (PG group) and another ten patients served as controls. Platelet function was determined ex vivo by measuring the adenosine diphosphate-, collagen-, and ristocetin-induced aggregation in platelet-rich plasma. A significantly higher platelet aggregability was measured in the PG group throughout the whole operation for ADP (1 and 2 mumol/L) and collagen (0.5 micrograms/ml). The same was true for collagen (1 microgram/ml) and ristocetin (1.2 mg/ml) after reperfusion. Not only the postreperfusional decrease in platelet aggregation but also the decline in platelet count that occurred in the control group could be prevented greatly by PGE1 infusion. In the perfusate, released from the liver graft vein by flushing with arterial blood, a significantly lower platelet aggregability was seen in comparison with the systemic circulation before reperfusion in the control group, a difference that was not found when PGE1 infusion was given intraoperatively. However, blood product requirements during OLT were comparable in both groups. In conclusion, PGE1 therapy during OLT preserves platelet function and prevents the drop in platelet count observed in the control group after revascularization.

Adenosine Diphosphate↗
PubMed1993

Microcirculatory effects of hyperthermia and 5-fluorouracil in the skin of nude mice.

During cancer chemotherapy physical manipulation of skin perfusion by hyperthermia can limit therapeutic efficacy. Because it is important to know microcirculatory responses to those forms of treatment, we used the ear of the lightly or not at all anesthetized nude mouse (rnü/rnü). To test, if whole body hyperthermia (WBH) and 5-fluorouracil (5-FU) acutely affect skin microvessels, we applied red light (group 1). 5-FU was injected prior to WBH, to test for effects of 5-FU on WBH (group 2). Respiratory rate increased and medium sized and small arterioles constricted during WBH in both groups and cutaneous perfusion decreased. 5-FU did not change these results. There were more leucocytes rolling along the vessel wall of small and medium-sized venules after 5-FU treatment (compared to BL). Our data suggest that activation of sympathetic tone by an external heat source compromises skin perfusion and could decrease the amount of cytostatic agents to that organ during WBH. Finally, there is more intense interaction among leucocytes and endothelial cells omit in response to 5-FU.

Animals↗
PubMed1992

Different aprotinin applications influencing hemostatic changes in orthotopic liver transplantation.

The effect of different aprotinin applications on hemostatic changes and blood product requirements in orthotopic liver transplantation was investigated in a prospective, open, and randomized study. From November 1989 to June 1990, 13 patients received aprotinin as a bolus of 0.5 Mill. Kallikrein inactivator units (KIU) on three occasions in the course of an OLT, whereas 10 other patients were treated with continuous aprotinin infusion of 0.1-0.4 Mill. KIU/hr. Before and after reperfusion of the graft liver, signs of hyperfibrinolysis, measured by thrombelastography, were significantly lower in the infusion group. Tissue-type plasminogen activator (t-PA) activity increased during the anhepatic phase but to a significantly lesser extent in the infusion group. Blood product requirements during OLT were tendentiously higher in the bolus group but not significantly so. However, the use of packed red blood cells was significantly lower in the postoperative period, whereas there was no significant difference in fresh frozen plasma requirements between the two groups. All 23 patients have survived, and only one woman of each group required retransplantation due to severe host-versus-graft reactions. Furthermore, we investigated the perfusate of the graft liver in both groups and detected signs of a decreased t-PA release in the infusion group. Our results demonstrate an advantage of aprotinin given as continuous infusion over bolus application in OLT.

Aprotinin↗
PubMed1992

Decreased platelet aggregation after reperfusion in orthotopic liver transplantation.

Increased blood loss is a major contributory factor to postoperative short- and longterm outcome in orthotopic liver transplantation (OLT). Hyperfibrinolysis, occurring mainly in the anhepatic phase, and disseminated intravascular coagulation (DIC), starting immediately after reperfusion, have been observed to parallel increased bleeding tendency. However, other factors may also contribute. For the first time we investigated platelet aggregation during the course of 10 OLTs and found a marked reduction of adenosine diphosphate-, collagen-, and ristocetin-induced platelet aggregation immediately after reperfusion. Since this is the point at which increased bleeding tendency is known to occur, it would seem that, apart from DIC and hyperfibrinolysis, an intermediate dysfunction of platelet aggregation may be a major cause of intraoperative bleeding.

Adenosine Diphosphate↗
PubMed1992

[Effect of leukocyte depleting polyester filters on thrombocytapheresis concentrates].

We studied platelet loss, leukocyte depletion, T/B cell ratio, platelet morphology and platelet function (aggregation, hypotonic shock reaction, retention and retraction) prior to and after filtration through two different polyester filters (Sepacell PL-5A, Pall PL100) as well as the posttransfusional platelet increment 1 h after transfusion in 8 pairs of single-donor platelet concentrates (Cobe Spectra, Fresenius AS 104). Leukocyte depletion was effective (>99.9%) and platelet loss acceptable in both filters, all tests showing no indication of a diminished platelet function by filtration.

Blood Component Transfusion↗
PubMed1992

[Changes in thrombocytapheresis concentrations caused by leukocyte depletion with polyester filters].

We studied platelet loss, leukocyte depletion, T/B-cell-ratio, platelet morphology and platelet function (aggregation, hypotonic shock reaction, retention and retraction) prior to and after filtration through two different polyester filters (Sepacell PL-5A, Pall PL100) as well as the posttransfusional platelet increment 1 h after transfusion in 8 pairs of single donor platelet concentrates (Cobe Spectra, Fresenius AS 104). Leukocyte depletion was effective (greater than 99.9%) and platelet loss acceptable in both filters, all tests showing no indication of a diminished platelet function by filtration.

Hemofiltration↗
PubMed1992

[The place of radioimmunoscintigraphy in the diagnosis and follow-up of ovarian cancer in comparison with computed tomography and second-look surgery].

In this prospective study the diagnostic capability of radioimmunoscintigraphy (RIS) was compared with that of computed tomography (CT) and of "second look" surgery as primary diagnostic procedures in 27 patients and in the follow-up of 52 women suspected of suffering from ovarian cancer. The results were compared with immunohistochemical findings and CA125 serum levels. For primary diagnosis sensitivity, specificity and diagnostic accuracy of RIS was 100%, 60% and 90%, resp. In follow-up, sensitivity for local recurrencies was 75% and specificity 68%. Peritoneal carcinosis in the pelvis and lower abdominal region was better detectable by RIS, but for detection of liver metastases CT showed better results. CT and RIS could not replace "second look" surgery.

Adult↗
PubMed1991

[Recurrent thromboembolism due to increased acetylsalicylic acid-resistant platelet aggregation].

A 49-year-old man had for 30 years suffered from severe recurrent thromboembolism with leg-vein thrombosis, pulmonary emboli, mesenteric infarction, cerebrovascular accident, cerebral vein thrombosis, portal vein thrombosis and femoral artery occlusion requiring leg amputation. In addition to moderately increased clotting activation with single-fold positive demonstration of fibrin monomers and a D-dimer concentration of 1 mg/l platelet aggregation was increased and could not be influenced by aspirin, 300 mg daily. Despite aspirin there were recurrent transitory attacks of cerebral ischaemia. Fibrin monomers were threefold positive and D-dimer concentration was increased to 4 mg/l (elevated clotting activation). Ticlopidine administration (250 mg daily) reduced adenosine diphosphate-induced platelet aggregation by 30% without effect on collagen-induced platelet aggregation. In parallel to these changes the patient's general condition clearly improved: fibrin monomers were no longer demonstrated and the D-dimer level fell to 0.5 mg/l.

Aspirin↗