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Biomedical subjects

C Gauwerky

Publications and source records attributed to C Gauwerky.

9 recordsLinked to original sources
PubMed1980

Growth hormone polypeptides stimulate proliferation of K562 human erythroleukemia cells.

The growth-promoting effect of growth hormones and related polypeptides was examined in vitro with a clonogenic assay using human erythroleukemic cells (K562). The erythroleukemia cells were grown in a serum-substituted methylcellulose culture system and colonies counted after 4 days' incubation. Human growth hormone (hGH) was a potent stimulant for K562 cell growth (60% augmentation). The cys(Cam)53-hGH(1-134) fragment of hGH and human chorionic somatomammotropin had less than half the activity of the intact hGH molecule. Bovine growth hormone was inactive in enhancing K562 colony formation. K562 cell proliferation was stimulated by hGH at concentrations as low as 0.1 ng/ml. Insulin stimulated K562 cell proliferation most effectively at a concentration of 1 ng/ml. The K562 culture system may conveniently be employed for determining the in vitro bioactivity of hGH.

Cell Division↗
PubMed1980

Hormonal effects on cell proliferation in a human erythroleukemia cell line (K562).

We have investigated the hormonal responsiveness of K562 cells using a serum-substituted in vitro clonogenic assay. Dexamethasone inhibited colony formation by the K562 cells, and the inhibitory effect could be reversed by progesterone (10(-6) M). Fluoxymesterone caused a prominent enhancement of K562 colony growth, whereas estriol had no effect. Stimulation by triiodothyronine was maximal at 10(-7) M, and the thyroid effect could be abrogated by the beta 2-adrenergic antagonist butoxamine in equimolar concentrations. Using standard tissue culture conditions, the beta-adrenergic agent isoproterenol, but not the alpha catecholamine phenylephrine, enhanced the proliferation of K562 cells. When K562 cells were grown under hormone-depleted conditions, they developed responsiveness to phenylephrine and were no longer stimulated by isoproterenol. DbcAMP and prostaglandins of the E series also caused K562 colony enhancement. Prostaglandin F2 alpha had no effect on cell proliferation. Insulin was an effective stimulant of colony formation of K562 cells, as were human growth hormone and ovine prolacin. Bovine growth hormone had no effect. Our results are consistent with the identificaiton of K562 as an erythroid line, and they indicate that K562 cells respond to endocrine hormones in a manner analogous to normal erythroid progenitors.

Butoxamine↗
PubMed1975

[Electrode problems in pacemaker wearers (experiences with three electrode types) (author's transl)].

3 types of electrodes (Medtronic 6903, EMT 588, MIP 2000) of 123 patients are examined by following criterial 1. rate of dislocation, 2. development of threshold, 3. time of application. We found: The Medtronic has the smallest rate of dislocation, the lowest range of threshold and is quickly placed in the right ventricle. The rate of dislocation of the EMT 588 is still just acceptable and it also has a sufficient low threshold, but in comparison to the other helical-wire electrodes the disadvantage of being rather difficult to place in the right ventricle. The MIP 2000 has not proved to be useful due to its large rate of dislocation.

Electrodes, Implanted↗
PubMed1975

[New protease-inhibitors with broad specificity in the polychaet Sabellastarte indica (Savingny), I (author's transl)].

In this paper we describe new and so far unknown protease inhibitors present in the tentacles of the annelid Sabellastarte indica Savingny. At least five different isoinhibitors with inhibitory activity towards trypsin, plasmin, chymotrypsin and kallikrein can be separated electrophoretically. Our protease inhibitor active material differs from the other well known protease inhibitors found in invertebrates in its high molecular weight, in that it is heat-labile and in the occurrence of the isoelectric point in the weakly acid region. On the other hand, the new protease inhibitors have some similarities to the soybean inhibitor described by Kunitz, and to ovomucoid. We also discuss the possibility that these inhibitors may influence the fibrinolytic system.

Animals↗