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Biomedical subjects

U Essers

Publications and source records attributed to U Essers.

At least 37 records · Page 2Linked to original sources
PubMed1979

[On the existence of a myeloproliferative factor in patients with a myeloproliferative syndrome (author's transl)].

Serum of patients suffering from a chronic myeloproliferative disorder (polycythaemia, era, osteomyelofibrosis, chronic myeloid leukaemia) and serum of lethally irradiated rats injected before application of a single doses of erythropoietin did not enhance the effect of erythropoietin -- measured with the iron incorporation rate of polycythemic mice. The rationale for these experiments is to try to find a "myeloproliferative factor", which augments the number of stem cells as described in sera of patients with polycythaemia vera, osteomyelofibrosis, and lethally irradiated mice.

Adult↗
PubMed1978

Preparative isolation of middle molecular weight fractions from the hemofiltrate of patients with chronic uremia.

Fractions in the molecular weight range of the so-called middle molecules (500--3000 daltons) were isolated on a preparative scale from hemofiltrate of patients. Hemofiltration was performed with an RP-6 dialyzer using a predilution technique. The hemofiltrate was concentrated and desalinated by reverse osmosis with membranes with a normal cut-off of 500 daltons. The retentate was freeze-dried, redissolved in volatile buffer and fractionated on Sephadex G-15 macrocolumns. The middle molecule molecular weight range in the elution profiles (detected at 206 and 280 nm simultaneously) was marked with peptides. Isolated fractions in the middle molecule molecular weight range showed strong inhibitory activity upon 3H-thymidine incorporation into rat bone-marrow cells in vitro. The described combination of hemofiltration, reverse osmosis and gel chromatography is suggested as a useful approach to the isolation of these ninhydrin-positive substances which, according to their proved heterogeneity, are to be subfractionated by further procedures.

Chromatography, Gel↗
PubMed1975

[Effect of higher molecular urine metabolites on lymphocyte transformation and autohemolysis (author's transl)].

Possible toxic effects of lyophilised not dialysable residue from urine of healthy persons obtained by 4 days dialysing against water were investigated. Therefore, the substance dissolved at a concentration of 2.22 mg/ml in Medium TC 199 respectively in physiological saline solution was added with increasing quantities (0.1 to 1.0 ml) to lymphocyte cultures (3 x 10(6) cells in 4 ml medium) and to erythrocytes (3 ml of blood after separation of granulocytes) from healthy persons. Spontaneous 3H-thymidine uptake of the lymphocytes ascertained 5 days after beginning of incubation was markedly depressed with dependence upon the doses up to 30.4% of the control value, whereas only 65.2% was reached after stimulation with 400 mug PHA. In both cases LDH activity in the supernatant culture medium measured as a parameter of cell destruction showed a dose-dependent increase with inverse trend as compared to 3H-thymidine uptake levels. This negative correlation may be due to impaired cell viability as the main cause for depressed lymphocyte transformation. The autohemolysis of the erythrocytes was diminished with dependence upon the doses until to 59.3% of the control value. Therefore, only cytotoxic effects of uremic serum on the lymphocytes may be due to higher molecular urine metabolites retained in uremia whereas increased autohemolysis will be induced by toxins of lower molecular weight.

Cell Survival↗
PubMed1975

[Spontaneous lymphocyte transformation in chronic renal insufficiency (author's transl)].

3H-thymidine uptake of lymphocytes cultured from patients with regular dialysis treatment was determined at the time of maximal transformation, which was ascertained in previous investigations to be 5 days after the beginning of incubation. Spontaneous DNS synthesis was found to be significantly depressed: 1137 plus or minus 1122 c.p.m./culture; controls: 9783 plus or minus 7499 c.p.m./culture, whereas LDH activity in the supernatant culture medium measured as a parameter of continuous cell destruction showed no alteration. After stimulation with 400 mug PHA DNS synthesis in 7 patients was also decreased, but elevated in 5 patients with previous infections. After incubation with added serum from 11 chronic uremic patients, spontaneous lymphocyte transformation in cultures sampled from 2 healthy subjects was also found to be depressed with positive correlation to the hemoglobin and hematocrit levels in the corresponding blood. The significantly increased LDH activity values in the medium as the consequence of impaired cll viability showed also positive correlation with 3-H-thymidine uptake levels; therefore depressed DNS synthesis cannot be due alone to accelerated cell destruction. In analogy to the erythrocytes, two stimultaneous effects of uremic toxins in serum are assumed to be exerted on the lymphocytes: metabolic inhibition of DNS synthesis and impaired cell viability.

Blood Urea Nitrogen↗