Biomedical subjects

M Jochum

Publications and source records attributed to M Jochum.

131 records · Page 8Linked to original sources

PubMed1981

Effect of human granulocytic elastase on isolated human antithrombin III.

The interaction of elastase isolated from human granulocytes with purified human antithrombin III was investigated. Antithrombin III did not display any inhibitory effect on granulocytic elastase. Dependent on enzyme concentration, however, granulocytic elastase induced progressive inactivation of antithrombin III leading to an almost complete loss of the thrombin inhibitory activity at a molar ratio of elastase: antithrombin III = 0.4:1 within 5 min at 25 degrees C. Antithrombin III is not drastically degraded by elastase as revealed by polyacrylamide gel electrophoretic and rocket immunoelectrophoretic investigations. However, characterization by two-dimensional immunoelectrophoresis with heparin in the first dimensional gel layer revealed a distinct change in the electrophoretic mobility of the inhibitor preincubated with elastase compared to native antithrombin III. This indicates that heparin binding sites of antithrombin III are occupied or affected by the elastase-induced peptide bond cleavage(s). Granulocytic proteinase inhibitors (eglin, Bowman-Birk inhibitor) proved to be highly effective in preventing the antithrombin III inactivation by degradation due to elastase. It is assumed that at least part of the antithrombin III consumption in diseases such as septicemia or endotoxemia is due to proteolysis by granulocytic proteinases. Application of specific inhibitors in the early phase of these ailments should be able to prevent this unspecific degradation of the endogenous antithrombin III.

Antithrombin III↗

PubMed1979

[Hyperdynamic septic shock in man: concentration course of selected coagulation factors and plasma proteins].

Coagulation factors and plasma proteins are significantly decreased in patients with hyperdynamic septic shock. Besides the activation of the coagulation system, the endotoxin-induced release of granulocyte proteases is responsible for a septic disseminated intravascular coagulation. In this situation special emphasis should be placed on the levels of antithrombin III regarding application of heparin.

Antithrombin III↗

PubMedDate not supplied

[3D-Culturing of human osteoblastic cells with vessel like nutrient supply].

AIM: The treatment of large, critical-size bone defects is a major therapeutic problem in orthopaedic and reconstructive surgery. The engineering of bone tissue could be used to replace lost bone mass. However, scaffolds seeded with vital cells and cultured in vitro suffer from poor oxygen and nutrient supply centrally, when the constructs exceed a critical volume. Therefore, we have established an osteoblastic cell culture in a new 3D-culture chamber with an artificial, vessel-like central membrane, allowing continuous nutrient supply. METHOD: Human osteoblasts were cultured in a 3D-like manner using a perfusion chamber for one week. In this system, the nutrient supply is guaranteed by a vessel-like, semipermeable polysulfone membrane with a continuous flow of medium. After fixation and cryosectioning, histological and immunohistological staining and scanning electron microscopy was carried out. RESULTS: Examinations reveal 3D cell growth around the central vessel. Formation of an extracellular matrix, rich in collagen type I and fibronectin, was detected immunohistochemically. Furthermore, we demonstrated cell adherence to the membrane and examined the surface morphology by scanning electron microscopy. CONCLUSION: The innovative approach for 3D-culturing of human osteoblasts in a system with a central nutrient supply opens up new possibilities for the in vitro cultivation for tissue engineering.

Cell Culture Techniques↗

PubMedDate not supplied

Granulocyte elastase as a sensitive diagnostic parameter of silent male genital tract inflammation.

Elastase, a specific inflammatory parameter of polymorphonuclear (PMN) granulocytes, was quantified with a sensitive enzyme immunoassay in the ejaculates of 188 patients consulting the andrological outpatient service. Correlations of the elastase concentrations to other parameters used up to now for the diagnosis of silent male genital tract inflammation were statistically evaluated by the CHI2-test. A correlation was found neither to the percentage of morphologically intact spermatozoa in the differential spermiocytogram and the total number of spermatozoa nor to the pH-value and viscosity of the ejaculate. However, release of elastase into the ejaculates was clearly associated with the occurrence of bacteria in native and stained smears or with the numbers of round cells present. Moreover, leukocyte counts in stained smears as well as an inflammation coefficient were highly significantly correlated to elastase concentrations. Obviously, quantification of granulocyte elastase in seminal plasma enables a rapid diagnosis of silent male genital tract inflammation, since even a single determination gives a reliable criterion and sequential determinations may allow the control of the course of the disease during therapy.

Adolescent↗

PubMedDate not supplied

Release of granulocyte proteinases during hemodialysis.

Neutral proteinases of neutrophilic polymorphonuclear leukocytes were followed up cytochemically in blood smears of 12 patients submitted to regular hemodialysis treatment (RDT). Halo formation (ring-shaped area around each neutrophil due to protein degradation) was reduced in all patients with end-stage renal disease under RDT. Concomitant to the development of leukopenia, a maximal increase of the plasma levels of the granulocytic elastase in complex with alpha 1-proteinase inhibitor was observed 3 h after starting hemodialysis (+409%; p less than 0.001). On the other hand, the proteolytic activity of the plasma samples against azocasein as substrate, being significantly higher (+244%; p less than 0.001) in RDT patients compared with healthy controls, decreased permanently during therapy (-71%; p less than 0.001; 3 h after initiation of the treatment). The mechanisms of release as well as of elimination of proteolytic activity due to RDT are discussed.

Adult↗