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U Willenbockel

Publications and source records attributed to U Willenbockel.

6 recordsLinked to original sources
PubMed1995

Thrombomodulin and ristocetincofactor in homocystinuria: a study in two siblings.

Homocystinuria due to cystathionine-beta-synthase deficiency (CBS-def-HOCY) initially often presents with vascular disorders, e.g. thromboembolic events. The measurement of vascular endothelial markers in plasma could help to assess endothelial damage. We determined von Willebrand factor (measured as Ristocetincofactor, RiCoF) and thrombomodulin (TM), two endothelial cell markers to our knowledge not measured systematically before in homocystinuria patients in a longitudinal study of two homocystinuric patients: Patient1 with thromboembolic disease and his asymptomatic sister, patient2. Before start of therapy in patient 1, TM and RiCoF levels both were increased. In patient 2 a moderately elevated RiCoF and a normal level of TM were found. Vitamin therapy with 15 mg folate and 600 mg pyridoxine per day led to almost complete normalization of amino acids in urine and plasma, and complete normalization of RiCoF and TM levels in both patients. Thus, TM and RiCoF elevations demonstrate that CBS-def-HOCY leads to endothelial cell damage, which resolved under vitamin therapy in the patients studied.

Adult↗
PubMed1994

Coagulation factors and markers of activation of coagulation in homocystinuria (HOCY): a study in two siblings.

Homocystinuria due to cystathionine-beta-synthase deficiency (CBS-def-HOCY) initially often present with thromboembolic events. In most cases in which coagulation factors have been analysed, a deficiency of AT-IIIc and factor VIIc has been reported, the cause of which has not been elucidated. Activation of coagulation with consumption of coagulation factors has been postulated as the mechanism. This paper reports a longitudinal study of two patients: patient 1 with thromboembolic disease and his asymptomatic sister, patient 2. Before start of therapy in patient 1, a reduction of FVIIc, other coagulation factors, and AT-IIIc was found. Markers of activation of coagulation (F1 + 2, TAT, FM, D-dimers) were elevated only in patient 1, and only at the time of thrombotic complications. In patient 2 reduced levels of FVIIc and other coagulation proteins, and a low borderline AT-IIIc level was found. Thus, in the two patients, sustained activation of coagulation can be reasonably excluded to be the cause of low levels of coagulation proteins. Vitamin therapy with 15 mg folate and 600 mg pyridoxine per day led to almost complete normalization of amino acids in urine and plasma. Thrombosis has not recurred to date. FVIIc and the other coagulation proteins and AT-IIIc increased in parallel with the biochemical remission. Direct inhibition of the activity of AT-III and coagulation factor VIII and other factors by homocysteine was attempted in vitro but could not be shown at HC concentrations known to occur in the plasma of HOCY patients. Therefore, in these patients, deficient synthesis of coagulation factors and AT-III due to a disturbance of amino acid metabolism is still the most probable explanation for the observed low levels.

Adult↗
PubMed1983

Survival time in cystinosis. A collaborative study.

In a retrospective study the overall survival time of 205 cystinotic patients of six countries was determined. The median survival time was 8.5 years. The median time for 'renal death' (age at death due to uraemia or age at starting renal replacement therapy) was 9.2 years. The youngest patient dying of renal death was 5.2 years. No sex difference in survival time was noticed. Furthermore no difference in survival time was noted between the different countries. The analysis of the overall survival curve indicates no clear differences between the infantile and adolescent types of cystinosis.

Adolescent↗