Biomedical subjects
Publications and source records attributed to W Schramm.
Combined oral contraceptives show clear differences in effect on the tissue factor-initiated coagulation test of activated protein C resistance, which is dependent on the presence and dosage of levonorgestrel. Multiphasic levonorgestrol oral contraceptives differ from monophasic contraceptives and resemble third-generation contraceptives.
Due to the complexity of alterations in hemostasis, replacement therapy in multiple organ dysfunction is a domain for nonspecific replacement therapy by means of fresh frozen plasma. Refined methods of virus inactivation as well as the consequent declaration of the major components of plasma derivatives have led to an increasing use of high-purity blood coagulation factor concentrates. Furthermore, the problem of activated factors and their inherent thrombogenic effect is meanwhile considerably attenuated. In the future, the availability of high-purity blood coagulation factor concentrates with a defined amount and quality of their factor content will enable a specific replacement therapy in single or multiple organ dysfunction in addition to unspecific replacement therapy by fresh frozen plasma
HISTORY AND ADMISSION FINDINGS: A 52-year-old woman was admitted because of pain for several days in the lower left leg and increasing pretibial swelling with livid discoloration. Six months before she had undergone a bilateral adnexectomy with removal of the omentum and subsequent chemotherapy for ovarian cancer. INVESTIGATIONS: Duplex sonography on the day of admission revealed thrombosis of the left popliteal vein with an unobstructed femoral vein. Both the quick value (89%) and partial thromboplastin time (PTT, 35.9 s) were within normal limits. Computed tomography and sonography were highly suspicious of a local recurrence of the ovarian cancer with peritoneal carcinomatosis. TREATMENT AND COURSE: PTT-effective heparinization (heparin-Na) was initiated together with overlapping anticoagulation with phenprocoumon (thromboplastin time 20-30%). On the 9th day after starting phenprocoumon painful, black necrotic changes began to appear on the skin of the left first to fourth toes. Assuming these to be due to phenprocoumon, anticoagulation was switched to low-molecular heparin (Enoxaparin), and antithrombin III and protein C were administered. A few days later thrombosis of the right iliac vein occurred, probably caused by local recurrence of the ovarian cancer. No palliative chemotherapy was undertaken in view of the thrombotic complications. The patient died a few months later from the cancer. CONCLUSION: If there is an underlying malignancy, chemotherapy and therapeutic vitamin-K antagonism in the presence of thromboembolic complications increases the risk of lowering protein C activity and may cause the rare complication of skin necrosis, induced by phenprocoumon.
The purpose of this study was to investigate the safety and efficacy of a novel vascular sealing device that incorporates a unique low-profile balloon-positioning catheter and a procoagulant delivered after diagnostic cardiac catheterization and percutaneous transluminal coronary angioplasty (PTCA) procedures. Current management of the vascular access site after percutaneous interventions is associated with patient discomfort and complications. Based on previously reported successful results in canine models, we proceeded with this first human feasibility and safety study. Immediately after an invasive procedure, the sealing device was successfully deployed at the femoral arterial access site in 24 of 24 procedures (diagnostic 19, PTCA 5). All patients were followed up at 1 month with clinical assessment, ankle-brachial index measurement, and Doppler ultrasound. Successful hemostasis was achieved in all patients. The activated clotting time before sealing device deployment was 125.5 +/- 22.2 and 267.8 +/- 60.0 seconds for diagnostic and PTCA patients, respectively. The time to hemostasis was 2.5 +/- 0.9 minutes for diagnostic and 6.0 +/- 2.2 minutes for PTCA patients. No major complications were observed. Coagulation markers (fibrinogen, D-dimer, thrombin-antithrombin-3 complex, and prothrombin fragment 1 and 2) measured before and after sealing device deployment did not reveal excessive intravascular thrombin generation or other coagulopathy. This novel vascular sealing device successfully achieves safe and effective vascular access site hemostasis immediately after cardiac catheterization and PTCA. These promising first human results will need to be confirmed by a multicenter randomized trial.
BACKGROUND: Studies over the last years provided empirical evidence that low-molecular weight heparins (LMWH) have advantages over unfractionated heparin (UFH) as post-operative thromboprophylactic agents. A detailed perspective economic evaluation for Germany is not available. METHODS: A deterministic decision-tree analysis was developed to estimate the main cost-relevant pathophysiological events: deep vein thrombosis (DTV), pulmonary embolism (PE) and major bleeding complications (BC) in general and orthopaedic surgery. The specific costs were analysed, summed up and put into relation with saved lifeyears from the perspective of society, third party payer and hospital management. The robustness of these results were substantiated by a detailed sensitivity analysis. RESULT: LMWH avoids pathophysiological events, saves costs and lifeyears in general and orthopaedic surgery from all perspectives. CONCLUSION: The use of LMWH as post-operative thromboprophylactic agents is more cost-effective than UFH in Germany.
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The PROSIT (Proteinuria Screening and Intervention) Project started in 1993 in order to obtain data on the prevalence of micro- and macroalbuminuria in diabetic patients treated in primary care, to establish an easy screening programme for microalbuminuria, in which also diabetic patients can participate in self-responsibility, and to implement a specific intervention programme for incipient nephropathy. In 58 representative doctor's offices 647 diabetic patients were included, who performed at home self-tests for microalbuminuria on three days within one week using the early morning urine and a newly developed qualitative immunologic test-strip for microalbuminuria. After storage they returned the same urine samples to their doctors' offices for semiquantitative retesting with the immunologic test-strip Micral-Test II. In case of positive results the proteinuria dipstick Combur-9-Test was applied in order to exclude other causes of positive microalbuminuria (e.g. urinary tract infection). Data of 569 patients (6% Type 1, 88% Type 2 and 6% secondary diabetes) could be analysed. Both qualitative self-testing for microalbuminuria at home and semiquantitative retesting in doctors' offices were found to be feasible. Based on semiquantitative retesting the prevalences of microalbuminuria (macroalbuminuria) were 19.6% (0%) in Type 1 diabetes, 17.2% (10.8%) in Type 2 diabetes and 11.7% (7.8%) in secondary diabetes. Type 2 diabetic patients showed a clear correlation between albuminuria and diabetes duration, HbA1c, serum creatinine, triglycerides as well as micro- and macrovascular complications. 227 patients with micro- or macroalbuminuria were included into the ongoing PROSIT intervention programme.
BACKGROUND: Early detection of vascular impairments after free tissue transfers are essential to prevent flap failure. Near-infrared spectroscopy showed good promise to monitor flaps at deep levels successfully without being invasive. The purpose of this study was to test whether the INVOS 3100 cerebral oxymeter is capable of detecting circulatory impairments. METHODS: In 10 healthy adults, near-infrared spectroscopy was used to measure regional saturation values during tourniquet ischemia and venous outflow restriction, in two test cycles. The probe, containing an infrared-light-emitting source and two infrared-light sensors, was placed below the elbow above the brachioradialis muscle. Statistical comparison of the data was performed using the Friedman test and the Wilcoxon-Wilcox test. RESULTS: Venous and arterial occlusions were characterized by an instantaneous fall of the regional saturation. Arterial occlusion showed a mean decrease of the saturation values down to 28+/-9%, whereas venous occlusion showed a mean fall of saturation values down to 51+/-12%. These falls were significant after 3 minutes of occlusion compared with baseline values (74+/-6%). The differences between arterial and venous occlusions were statistically significant. CONCLUSION: This study, designed to test less-expensive equipment, was able to measure absolute values, and was not prone to interference caused by probe movement, providing information on the oxygenation profile accurately and noninvasively, and distinguishing between arterial and venous occlusion.
This study was performed to determine the feasibility of using saliva as a diagnostic medium for the detection of antibodies to human immunodeficiency virus type 1 (HIV-1) and HIV-2 under nonlaboratory conditions and to evaluate the performance characteristics of such a test. We developed for this purpose a self-contained kit (Saliva. Strip [ST]), which combines the collection and processing, as well as the analysis, of the specimen. The kit's performance was evaluated in a blinded study. Saliva collection was facilitated with a specially designed device that contains a sample adequacy indicator, and immunochromatography test strips were used for the analysis. A total of 1,336 matched serum and saliva specimens (684 reactive and 652 nonreactive specimens) were tested. We tested sera using an enzyme immunoassay (EIA) and a rapid strip test. Sera reactive in one of the assays were also analyzed by Western blotting. Sensitivity and specificity were 99.4 and 99.4%, respectively, for ST, 100 and 99.1%, respectively, for EIA, and 99.7 and 100%, respectively, for the serum strip test. The saliva test performed well when HIV-2-positive sera or a low-titer performance panel (HIV-1) of serum or plasma specimens were diluted (1:2,000) in nonreactive saliva. Because the methodology we present here uses a noninvasively obtained medium, the methodology may be suitable for use in the field where laboratory support and personnel are limited, such as community outreach programs, doctors' offices, surveillance studies, and community hospitals.
In AIDS therapy, attempts have been made to inhibit the virus-encoded enzymes, e.g. HIV-1 protease, using active site-directed inhibitors. This approach is questionable, however, due to virus mutations and the high toxicity of the drugs. An alternative method to inhibit the dimeric HIV protease is the targeting of the interface region of the protease subunits in order to prevent subunit dimerization and enzyme activity. This approach should be less prone to inactivation by mutation. A list of improved 'dimerization inhibitors' of HIV-1 protease is presented. The main structural features are a short 'interface' peptide segment, including non-natural amino acids, and an aliphatic N-terminal blocking group. The high inhibitory power of some of the lipopeptides [e.g. palmitoyl-Tyr-Glu-Leu-OH, palmitoyl-Tyr-Glu-(L-thyronine)-OH, palmitoyl-Tyr-Glu-(L-biphenyl-alanine)-OH] with low nanomolar Ki values in the enzyme test suggests that mimetics with good bio-availability can be derived for AIDS therapy.
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Recently, discussions focused on the question whether acquired activated (APC) resistance is a clue to the observed association between venous thromboembolism (VTE) risk and oral contraceptive (OC) use, especially with the so-called third-generation OC. The objective of our study was to check the validity of acquired APC resistance regarding VTE risk in a case-control study. Sixty-seven women with confirmed VTE diagnosis (n = 67) were consecutively ascertained in primary health care settings, interviewed and blood samples taken (at the earliest 6 months after VTE). Cases were age-matched to 290 population controls. Acquired APC resistance was measured as normalized APC ratio (APCRN). The effect of APC on tissue factor initiated thrombin generation was measured in plasma using alpha 2-macroglobulin attached thrombin activity as an endpoint. Higher risk (odds) ratio with 95% CI) of VTE for carriers of heterozygote Factor V Leiden mutation was confirmed [OR = 2.72 (CI:1.51-4.92)]. However, there is no association between VTE and the level of APCRN OR 0.65 (CI:0.35-1.22). We conclude that acquired APC resistance, measured with a tissue factor initiated test, is unlikely to have a direct association to the clinical outcome of venous thromboembolism.