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H Wurm

Publications and source records attributed to H Wurm.

46 records · Page 3Linked to original sources
PubMed1984

beta 2-Glycoprotein-I (apolipoprotein H) interactions with phospholipid vesicles.

The binding characteristics of the human serum protein beta 2-glycoprotein-I, also called apolipoprotein H, with multilamellar phospholipid vesicles has been studied. It was found that beta 2-G-I is not or almost not bound to the "neutral" phospholipids phosphatidylcholine (PC), phosphatidylethanolamine (PE) and sphingomyelin (SM). The negatively charged compounds phosphatidylserine (PS) and phosphatidylinositol (PI) interact strongly with beta 2-G-I. In terms of phospholipid concentration the binding to PS is about one order of magnitude greater than to PI. The binding capacity is influenced by several parameters such as the molarity of buffer, presence of mono- or divalent cations as well as ethylenediaminotetraacetic acid (EDTA). Proteins like bovine serum albumin (BSA), human serum albumin (HSA) or horse gamma-globulin (HGG) influence the binding also in a concentration dependent manner.

Edetic Acid↗
PubMed1982

Physiological and clinical aspects of respiration control in infants with relation to the sudden infant death syndrome.

We have examined the behavior of several variables which are related to respiratory control in 114 infants (up to 6 months of age) in order to assess the risk for the sudden infant death syndrome (SIDS), 23 of the infants had already had demonstratable serious or life threatening apneas or respiratory problems during surgical anesthesia. These infants were assigned as a risk group, and the rest of the investigated babies was taken as a control group. We found that practically all infants of the risk group had apneas during sleep, which lasted longer than 8 s each. Only 22% of the infants of the control group had apneas of such a duration. As a statistical parameter, calculated from at least 1 hour recording of respiration, we defined the mean apnea duration (MA-value) as average value of apnea duration time in seconds per minute of recording. The MA-value proved to be significantly elevated in the infants of the risk group. The trend to hypoxia in the infants of the risk group was also indicated by the observation of lower transcutaneous PO2-values (tc-PO2) during sleep, when compared with control infants. In agreement with this observation is the increase of the 2,3-DPG concentration and the decrease of the density of erythrocytes of the infants of the risk group. Breathing hypoxic gas mixtures tended to depress respiration in all infants tested, and, especially in the risk group, to elicit irregular respiratory patterns. On the other hand, we observed that inhalation of pure oxygen markedly stimulated respiration in all infants investigated. We conclude from these observations that a risk for SIDS may be related to a particular response pattern of the respiratory center during the early postnatal life. We are able to distinguish infants with a higher risk for SIDS from other children by determination of the MA-value during sleep.

Aminophylline↗
PubMed1982

Studies on the possible function of beta 2-glycoprotein-I: influence in the triglyceride metabolism in the rat.

Seven rats were infused with 14C-labeled Intralipid at a constant rate of 0.38 ml per hour over a time period of 4 hours. Four rats served as controls and received an infusion of 0.15 M NaCl or of serum albumin two hours after the start of the experiment. In these animals the plasma triglyceride concentration rose linearly from 30 to 240 min and paralleled the total blood radioactivity. The triglyceride concentrations at the end of the experiments were about 25 times as high as at the beginning. Three rats receiving 2 hr after the start an additional infusion of beta 2-glycoprotein-I at a rate of 10 mg per hr showed a markedly enhanced triglyceride removal from the plasma, reaching a steady state which lasted for more than 30 min. It is concluded that beta 2-glycoprotein-I affects the triglyceride clearance under these experimental conditions.

Animals↗
PubMed1981

Studies on the composition of the protein part of triglyceride rich lipoproteins of human serum: isolation of polymorphic forms of beta 2-glycoprotein-I.

Isoelectric focusing (IEF) of the apoproteins of triglyceride rich human serum lipoproteins gives rise to the separation of some 15-20 protein bands. Three of these bands have been isolated in pure form and were characterized as isoelectric species of beta 2-glycoprotein-I (beta 2G-I). To compare the amino acid composition of these polymorphic forms with a representative specimen of beta 2G-I from total serum it was also necessary to apply a novel isolation procedure using Rivanol, perchloric acid and Heparin-Sepharose affinity chromatography. With the possible exception of the Pro content, the three isoforms were chemically and immunochemically identical. The isoelectric points of the polymorphic forms were 5.75, 6.0 and 6.2. Their molecular weight was identical by SDS polyacryl amide gel electrophoresis (54 000 D).

Amino Acids↗
PubMed1980

[The influence of hemolysis on capillary blood plasma density measurements using the mechanical oscillator technique (author's transl)].

Sampling of capillary blood often yields slightly hemolytic plasma. We investigated the influence of hemolysis on plasma density using the mechanical oscillator technique. Plasma density rose by approximately 0.1 milligram when the hemoglobin content increased by 0.5 milligram. These values correspond to 0.3% hemolysis and were not exceeded in more than 70% of the investigated capillary plasma samples. In general, hemolysis must be taken into account if plasma density measurements are to be made with an accuracy better than 0.5 milligram, which corresponds to 2-3% of the plasma protein content.

Adolescent↗
PubMedDate not supplied

Platelet activation in normo- and hyperlipoproteinemias.

In the last few years it became obvious that platelets are involved in the development of atherosclerotic diseases. This involvement of platelets has been taken into account in the "response to injury" hypothesis of atherosclerosis. The hypothesis is based on the assumption that atherosclerotic lesions result from endothelial injury, followed by the interaction of vessel wall constituents with lipoproteins, macrophages, and platelets. In the first part of this review, general aspects of platelet activation are summarized and the pathways of platelet aggregation as well as their involvement in blood coagulation are discussed. The second part of this paper describes the influence of cholesterol, lipoproteins, and apolipoproteins upon the activation and metabolic behavior of platelets. Physiological and pathophysiological processes particularly occurring in different types of hyperlipoproteinemias and atherosclerotic disorders are discussed in this context.

Adenosine Diphosphate↗