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Biomedical subjects

H Riess

Publications and source records attributed to H Riess.

At least 91 records · Page 5Linked to original sources
PubMed1996

Internal jugular vein thrombosis caused by resistance to activated protein C as a complication of ovarian hyperstimulation after in-vitro fertilization.

We present a case of a 24 year old woman who became pregnant (twins) after human menopausal gonadotrophin (HMG)-induced ovarian stimulation, in-vitro fertilization (IVF) and subsequent embryo transfer. She developed a right internal jugular vein thrombosis as a complication of severe ovarian hyperstimulation syndrome (OHSS) 28 days after embryo transfer. The thrombosis developed in spite of anticoagulation with low-dose heparin. Later a resistance to activated protein C (APC) or Dahlbäck disease was diagnosed. Due to a new test procedure (accelerin inactivation test), the diagnosis was possible even under anticoagulation treatment. The coincidence of hyperstimulation and internal jugular vein thrombosis with the concurrent diagnosis of resistance to APC has not been published previously. The benefit of general screening for resistance to APC before admission to the IVF programme should be weighed. Targeted selection of a group of high-risk women would therefore be made possible.

Adult↗
PubMed1996

Simple and rapid detection of factor V Leiden by allele-specific PCR amplification.

Resistance to activated protein C is the most common hereditary cause for thrombosis and significantly linked to factor V Leiden. In this study, primers were designed to identify the factor V mutation by allele-specific PCR amplification. 126 patients with thromboembolic events were analysed using this technique, PCR-RFLP and direct sequencing. The concordance between these techniques was 100%. In 27 patients a heterozygous factor VGln506 mutation was detected, whereas one patient with recurrent thromboembolism was homozygous for the point mutation. Due to its time- and cost-saving features allele-specific amplification should be considered for screening of factor VGln506.

Alleles↗
PubMed1995

Malignant liver tumors treated with MR imaging-guided laser-induced thermotherapy: technique and prospective results.

PURPOSE: To evaluate magnetic resonance (MR) imaging-guided laser-induced thermotherapy (LITT) of liver metastases. MATERIALS AND METHODS: In a phase II study, 20 patients with 33 metastases from colorectal carcinoma (75%) or other primary tumors (25%) underwent LITT. MR thermometry performed with fast low-angle shot sequences was used to monitor therapy on-line, and dynamic and static contrast material-enhanced MR images enabled estimation of the degree of resultant necrosis. Follow-up studies were performed 3 months after thermotherapy. RESULTS: The thermosequences enabled accurate on-line monitoring in 85% of lesions. In 69% of lesions 20 mm in diameter or smaller, contrast-enhanced MR images depicted substantial necrosis, with a local tumor control rate of 69% after 6 months and 44% after 12 months. Among lesions larger than 20 mm, necrosis was frequently incomplete, with a local control rate of only 41% after 6 months and 27% after 12 months. CONCLUSION: MR imaging-guided LITT of liver metastases is a safe and promising therapy for liver metastases.

Adult↗
PubMed1995

A clinical comparative investigation of a non-linear versus linear hearing aid.

The objective of this study was to compare the effect and performance of a hearing aid (HA) having a non-linear amplification below 1600 Hz (test HA) with a linear amplifying HA (control HA), aiming towards identical target groups of hearing-disabled people. The investigation was designed as a single-blind crossover interview study, i.e. the interviewer was blind. Thirty-two experienced HA users at a median age of 74 years participated. The observation period was 6-8 weeks for both HAs. For several evaluation parameters the participants found the test HA superior to the control HA, and a significantly better effect of the test HA was indicated in person-to-person conversation in quiet surroundings. Also, quality of sound was significantly better in the test HA, and thus these parameters support the test HA, being preferred by 75%. No significant differences were found in the objectively evaluated parameter, i.e. speech recognition score in background noise (SRSN: S/N = 0) between the two aids. A one-year follow-up examination of those preferring the test HA demonstrated continuously frequent use and satisfaction with the automatic volume control. It is concluded that skilled HA users with a wide range of hearing impairment at an age of 60-80 years prefer a non-linear HA to their current linear HA when fitted monaurally--however, a certain bias in the unblinded test subjects cannot be excluded.

Aged↗
PubMed1995

[Graft-vs.-host reaction: a severe complication after orthotopic liver transplantation].

INTRODUCTION: Patients with solid-organ transplantation are at risk for Graft-versus-host disease (GVHD) even though GVHD is a rare phenomenon after orthotopic liver transplantation (OLT). CASE REPORT: The 30 yrs old male patient received an ABO compatible orthotopic liver graft for acute liver failure due to intoxication with amanita phalloides. Twenty-four days after OLT the patient developed high temperatures up to 40.0 degrees C and pancytopenia and was treated for CMV-infection. On postoperative day (POD) 32 an erythematous maculo-papular rash developed. A drug induced toxic epidermal necrolysis was suspected and treated with plasmapheresis for three days. Acute renal failure and respiratory insufficiency occurred while liver function was not impaired. A skin biopsy at that time showed no specific signs for GVHD. On POD 42 HLA-typing of circulating lymphocytes presented donor HLA phenotype and GVHD was established. Therapy with ATG was started but the clinical status of the patient did not improve. Following administration of OKT3 on POD 48 a reduction of activated CD-3 lymphocytes from 90% to 60% could be achieved. Due to the low platelet count the patient died of intracerebral hemorrhage on POD 52. CONCLUSION: Since a fully developed GVHD is rare after OLT and the similarity of the clinical findings to viral or drug induced diseases is high, diagnosis is often made late in the course of the disease. Furthermore, therapeutic measures for GVHD are scarce and diagnosis has to be established as early as possible, hence pretransplant procurement of donor and recipient mononuclear cells for later study should be considered to decrease the time period between clinical suspicion and diagnosis.

Adult↗
PubMed1995

[Laser-induced thermotherapy of liver metastases with MRI control. Prospective results of an optimized therapy procedure].

In a prospective study MR-guided laser-induced thermotherapy (LITT) of liver metastases was optimized and the clinical parameters evaluated. Seventeen patients (4 women, 13 men) with a total of 29 lesions underwent LITT in 25 sessions through 1 March 1994. Twelve of them suffered from colorectal carcinomas, 5 from other primary tumors. Under local anesthesia a maximum of 5 lesions per patient were treated. For MR-guided LITT a neodymium yttrium aluminum garnet laser (Nd-YAG 1064 nm) with energy varying from 3 to 7.5 W was used. Energy and application time were defined through a computer program; they varied, dependent on the lesion size, location and consistency. To monitor the progress of LITT two special thermosensitive MR sequences (Thermo-Turbo-FLASH and FLASH-2D sequences) were individually optimized, whereby the increase in temperature correlates with an increase in signal loss. All procedures were well tolerated without significant early or late side effects. In only one patient was minimal air documentated in the pleural cavity with spontaneous resorption. Patients were dismissed without complaints after 24-h hospitalization. The control parameters of the contrast-enhanced dynamic MRI documented at optimal response a hypointense signal around the tip of the laser applicator, in accordance with laser-induced necrosis. In lesions 20 mm or smaller, nearly 100% tumor necrosis was achieved and in lesions larger than 20 mm, only 50%. Follow-up evaluation 6 months after treatment shows a significantly better response in lesions with a diameter of 20 mm or smaller, with a local tumor control rate of 66%. In lesions larger than 20 mm only a local tumor control rate of 35% could be achieved. Laser-induced thermotherapy (LITT) represents a new, minimally invasive technique for tumor destruction and a high response rate in small liver metastases.

Adult↗
PubMed1994

Protein S in end stage liver disease and in the course of liver transplantation.

Protein S (PS) is mainly synthesized in the liver and in endothelial cells. Determination of PS levels is complicated by the fact that total PS antigen (total PS Ag) exists in plasma as free and functionally active protein (free PS Ag) and in a reversible inactive complex with C4b-binding protein. In blood samples from patients with end stage liver diseases we studied PS levels before, during and after orthotopic liver transplantation (OLT). Median levels of total and free PS Ag were below and within the lower part of the reference interval, respectively. Two different groups in PS distribution could be distinguished. In 70% of the patients with preoperative levels of total and free PS Ag within the reference interval showed an impaired free/total PS Ag ratio towards higher unbound and free PS Ag levels. With reperfusion of the graft liver total and free PS Ag decreased significantly and the free/total PS Ag ratio normalized. In 30% of the patients reduced PS Ag levels together with a normal free/total PS Ag ratio were seen. In the reperfusion phase no further reduction of total and free PS Ag could be observed.

Adult↗
PubMed1994

Thrombomodulin: a marker for endothelial damage during orthotopic liver transplantation.

Thrombomodulin is a surface protein of vascular endothelial cells. A smaller form of thrombomodulin in blood and urine, the soluble (s)thrombomodulin, appears to be derived from injured endothelial cells or to be proteolytically cleaved from thrombomodulin by proteases. Several in vitro and in vivo studies have suggested (s)thrombomodulin as a marker of endothelial damage. In orthotopic liver transplantation, platelet and leukocyte activation as well as prothrombin activation are suspected of being caused by damaged endothelial cells in the graft liver. We determined (s)thrombomodulin antigen as well as thrombin-antithrombin III complexes, protein C, and antithrombin III activities in the course of 23 orthotopic liver transplantations. Samples were taken at 7 different time-points intraoperatively, as well as out of the perfusate released from the graft liver vein during the flushing procedure with arterial blood prior to the opening of the hepatocaval anastomosis. Levels of (s)thrombomodulin antigen and thrombin-antithrombin III complexes showed a significant increase with reperfusion of the graft liver and levels in the perfusate were higher (both: P = 0.0001) than the corresponding systemic levels. In parallel, antithrombin III decreased significantly with reperfusion and perfusate levels of antithrombin III and protein C activities were lower in the systemic circulation (both: P = 0.0001). In conclusion, high levels of (s)thrombomodulin antigen in the early reperfusion phase and in the perfusate strongly indicate endothelial damage to the graft liver vascular bed, paralleled and followed by signs of prothrombin activation.

Antigens↗
PubMed1994

The effect of methylene blue phototreatment on plasma proteins and in vitro coagulation capability of single-donor fresh-frozen plasma.

BACKGROUND: Photodynamic virus inactivation of fresh-frozen plasma (FFP) may result in its impaired coagulation capability. STUDY DESIGN AND METHODS: Double-volume plasmapheresis samples from 11 donors were divided in pairs of 250 mL. One group underwent methylene blue (MB) phototreatment (MB-FFP). The other group was treated according to the standards of the American Association of Blood Banks for preparation and storage of FFP. Parameters of hemostasis and clinically important plasma proteins were tested in native plasma, thawed MB-FFP, thawed FFP, and twice-frozen and thawed FFP (FFP-II). RESULTS: Mean activities of factor V (73.4 vs. 94.5%; p < 0.01), factor VIII (58.1 vs. 86.7%; p < 0.001), and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) were reduced in MB-FFP as compared to those in FFP. The comparison of MB-FFP to FFP-II revealed reduced activities of factor VIII (58.1 vs. 85.2%; p < 0.001) and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) but no changes in factor V. Activated partial thromboplastin time in MB-FFP was prolonged beyond the upper normal range (+5.3 sec; p < 0.001) and prothrombin time increased in MB-FFP versus FFP (+0.96 sec; p < 0.001). CONCLUSION: MB phototreatment reduces the in vitro coagulation capacity of FFP, most likely as a result of the effects of an additional freezing and thawing procedure and photooxidation-induced protein damage.

Blood Coagulation↗
PubMed1994

Mediators of leukocyte activation play a role in disseminated intravascular coagulation during orthotopic liver transplantation.

Leukocytes play an important role in the development of disseminated intravascular coagulation (DIC). In the reperfusion phase of OLT a DIC-like situation has been described and has been held responsible for the high blood loss during this phase. We investigated the role of leukocytes in the pathogenesis of DIC in OLT by measuring the leukocytic mediators released upon activation (cathepsin B, elastase, TNF, neopterin) and the levels of thrombin-antithrombin III (TAT) complexes, seen as markers of prothrombin activation. Arterial blood samples were taken at 10 different time points during and after OLT. Samples were also taken of the perfusate released from the liver graft vein during the flushing procedure before the reperfusion phase. Aprotinin was given as a continuous infusion (0.2-0.4 Mill. KIU/hr) and its plasma levels were determined. Significantly elevated levels of neopterin (15-fold; P < 0.01), cathepsin B (440-fold; P < 0.01) in the perfusate, as compared with the systemic circulation, as well as their significant increases in the early reperfusion phase suggested that they were released by the graft liver. This was paralleled by elevated levels of elastase (1.3-fold, P < 0.05), TNF (1.5-fold, P = NS), and TAT complexes (1.4-fold; P < 0.1) in the perfusate. Significant correlations could be identified between the parameters of leukocyte activation and TAT complexes, whereas no correlation was observed between any of the parameters investigated and the aprotinin levels. Our results strongly indicate a release of leukocytic mediators from the graft liver during its reperfusion which seems to be related to the parallely increased prothrombin activation. No correlation could be seen between levels of aprotinin and levels of leukocytic mediators.

Adult↗
PubMed1994

Increased urokinase-type plasminogen activator (u-PA) levels in graft liver perfusate and decreased single chain u-PA activation with higher levels of aprotinin.

In orthotopic liver transplantation (OLT) the graft liver is perfused with arterial blood prior to the opening of the hepatocaval anastomosis. In the present investigation we focused on the reperfusion of the graft liver in order to study the hepatic influence in the regulation of urokinase-type plasminogen activator (u-PA levels). Two different aprotinin schedules were used in 43 patients. We measured u-PA levels in the perfusate and in the corresponding systemic circulation. u-PA levels were higher in the perfusate as compared to systemic blood samples despite the dilution of the perfusate sample by the preservation fluid. This suggests u-PA secretion by the graft liver. In the presence of lower aprotinin levels signs of single-chain u-PA (scu-PA) activation was in the perfusate more prominent than systemically--a difference which was not seen in the presence of higher aprotinin levels. This seems to be an argument for the effectiveness of higher dosed aprotinin application in preventing scu-PA activation.

Adult↗
PubMed1994

Ondansetron for efficient emesis control during total body irradiation.

Ondansetron is a 5-hydroxytryptamine receptor antagonist which has shown activity in the prevention of emesis following cytotoxic and radiation therapy for cancer. We describe our experience using ondansetron in 25 patients undergoing fractionated total body irradiation (TBI) 12 Gy/3 days as conditioning for bone marrow transplantation. Antiemetic efficiency was investigated during the 3 days of TBI prior to high-dose cytotoxic chemotherapy. Twenty-two of the 25 patients (88%) achieved sufficient emesis control with less than three emetic episodes whereas the remaining 12% experienced three to five emetic events during their worst 24-h period. Eleven patients (44%) had complete control with no vomiting at all. Of 75 'patient days', 52 (69%) were without any emesis, 20 (27%) were associated with one to two and only three (4%) with three to five emetic episodes. Headache occurred in four patients (16%). No other significant adverse effects were seen, in particular no extrapyramidal reactions due to ondansetron. Our data confirm that ondansetron plays a major role in the antiemetic management of patients undergoing TBI.

Adolescent↗
PubMed1994

Relation between leucocyte depletion and storage.

We intended to answer two questions: (1) Does storage time of platelet concentrates (PCs) influence the efficacy of leucocyte depletion by filtration? (2) Does pre-storage leucocyte depletion by filtration of PCs improve the post-storage quality? To this end we tested in parallel the halves of 10 double-sized PCs, one half stored after filtration through a polyester filter (PL 50, Pall), the other half filtered after a 5-day storage period. Efficacy of leucocyte depletion showed to be independent of the age of PCs, and pre-storage leucocyte depletion of PCs was not able to improve the quality of PCs stored for 5 days, as long as the leucocyte contamination of unfiltered PCs was lower than 0.5 x 10(8)/unit.

Adenosine Diphosphate↗
PubMed1993

Evolution of urokinase-type plasminogen activator (u-PA) and tissue-type plasminogen activator (t-PA) in orthotopic liver transplantation (OLT).

In orthotopic liver transplantation (OLT) hyperfibrinolysis seems to be of causative importance for intra- and postoperative bleeding. Although recently hyperfibrinolysis has been successfully reduced by intraoperative aprotinin treatment, small increases of fibrinolysis still remain during OLT. Originally, tissue-type plasminogen activator (t-PA) was considered to be responsible for the increases, but the efficacy of aprotinin which inhibits besides plasmin also kallikrein and urokinase-type plasminogen activator (u-PA) suggested also a role for the intrinsic and contact system-dependent plasminogen activators. We investigated the role of u-PA. From 29 patients undergoing OLT with intraoperative aprotinin infusion arterial blood samples were taken at 7 different time points. The preoperative median values for u-PA antigen (u-PA Ag) and plasmin-activatable single-chain u-PA (scu-PA) levels, which were more than 2-fold above normal (both: p < 0.01), decreased slightly during the preanhepatic phase and remained unchanged during the anhepatic phase. With reperfusion of the graft liver the two levels decreased significantly (p = 0.0003 and p = 0.006, respectively) to almost normal values, probably due to clearance by the graft liver. Active two-chain u-PA (tcu-PA) was preoperatively 2-fold above the detection limit, remained stable during the preanhepatic phase and increased 2-fold in the anhepatic phase (p = 0.0018). As expected tcu-PA also relapsed upon reperfusion, but to the preoperatively enhanced level, possibly caused by sustained activation of scu-PA by cathepsin B. t-PA activity levels were at the upper end of the normal range preoperatively, slightly increased during preanhepatic and anhepatic phases and decreased significantly with reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗