Biomedical subjects

C van den Bogert

Publications and source records attributed to C van den Bogert.

21 records · Page 2Linked to original sources

PubMed1981

Fluorometric determination of tetracyclines in small blood and tissue samples.

A reported fluorometric method to determine tetracycline in biological material was modified to determine low levels of the antibiotics when using only small amounts of starting material. The method is applicable to tissue distribution studies in small experimental animals and also can be used for serial determinations in blood samples of these animals and for biopsy material. The tetracyclines are extracted in the presence of ethylenediaminetetraacetic acid, and the phosphate precipitation steps are omitted. This omission makes the procedures considerably less time consuming. The recoveries of the tetracyclines, oxytetracycline and doxycycline, are approximately 80-100%. The values obtained by this method were consistent with those from microbiological assays, and its reliability was shown further in a comparison with the fate of radioactive tetracycline.

Bacillus cereus↗

PubMed1981

Arrest of in vivo proliferation of Zajdela tumor cells by inhibition of mitochondrial protein synthesis.

The proliferation of Zajdela tumor cells, grown in vivo in Wistar rats, is arrested by low amounts of oxytetracycline. Oxytetracycline is administered by means of continuous infusion in such a way that the oxytetracycline concentration in serum and ascitic fluid is maintained at a level at which only mitochondrial protein synthesis is blocked. Under these conditions, Zajdela mitochondrial tumor cells cease dividing after a few cell generations, an event which is preceded by reduction of cytochrome c oxidase activity of the tumor cells. Toxicity to host tissues is limited to the immune system which is apparently suppressed by the drug. Even so, oxytetracycline might have therapeutic potential in human cancer therapy, especially because it does not influence the hemopoietic system.

Animals↗

PubMed1976

The mitochondrial ribosomes of Neurospora crassa. II. Comparison of the proteins from Neurospora crassa mitochondrial ribosomes with ribosomal proteins from Neurospora cytoplasm, from rat liver mitochondria and from bacteria.

1. It has been shown by Datema et al. (Datema, R., Agsteribbe, E. and Kroon, A.M. (1974) Biochim. Biophys. Acta 335, 386--395) that Neurospora mitochondria isolated in a Mg2+-containing medium (or after homogenization of the mycelium in this medium and subsequent washing of the mitochondria in EDTA-containing medium) possess 80-S ribosomes; mitochondria homogenized and isolated in EDTA medium yield 73-S ribosomes. The ribosomal proteins of the subunits of 80-S and 73-S ribosomes were compared by two-dimensional electrophoresis. The protein patterns of the large, as well as of the small subunits are very similar but not completely identical; the most conspicuous difference is that the large subunit of 80 S contains about eight more proteins than the large subunit of 73 S. 2. The contamination by Neurospora cytoplasmic 77-S ribosomes in the 80-S preparations, if present, is only minor. 3. Neurospora cytoplasmic ribosomes contain 31 proteins in the large, and 21 proteins in the small subunit. 4. Neurospora 80- mitochondrial ribosomes contain 39 proteins in the large, and 30 proteins in the small subunit 30 proteins. 5. Rat liver mitochondrial ribosomes contain 40 proteins in the large and at least 30 proteins in the small subunit. About 50% of these proteins has an isoelectric point below pH 8.6. 6. The pattern of Paracoccus denitrificans is very similar to that of other bacterial ribosomes, the large subunit contains 29, the small subunit 18 proteins.

Animals↗