Biomedical subjects

J Krisinger

Publications and source records attributed to J Krisinger.

23 records · Page 2Linked to original sources

PubMed1989

Methylation of the vitamin D-dependent CaBP gene (calbindin 9 Kd) does not mediate tissue or vitamin D regulation.

The vitamin D-dependent intestinal calcium binding protein gene is predominantly expressed in the intestine. In this report we have examined the possibility that methylation of the gene might play a role in its tissue-specific expression employing genomic Southern analysis. None of the Hpa II and Hha I sites examined by the indicated probes in and around the gene were found to be methylated in the intestine, kidney and liver. No change in the methylation of these sites was detected in response to 1,25-dihydroxy-vitamin D3 administration to vitamin D-deficient rats under conditions which stimulate the expression of the gene. These results indicate that the rat intestinal calcium binding protein gene is not methylated in these tissues, at the indicated sites and, therefore, methylation seems not to be involved in the regulation of this gene's expression.

Animals↗

PubMed1989

[The effect of benzenecarboxylic acids--in particular mellitic acid--in in vitro biological system].

Influence of Benzenecarboxylic Acids, Particularly Mellitic Acid, on Biological in vitro Systems. In a first part of the present paper influences of mellitic acid and some other benzenecarboxylic acids on reduplication of Ehrlich ascites tumor cells cultured in vitro are reported. Mellitic acid in the concentration range between 1 and 5 mmol/l caused an increase, in concentrations of 10 mmol/l and above an inhibition of cell multiplication. Benzoic acid, phthalic acid, hemimellitic acid and pyromellitic acid showed in concentrations above 6 to 10 mmol/l inhibitory effects on cell multiplication. The second part reports studies on potential influences of mellitic acid on growth and mesenchymal metabolism of explanted murine fetal tibiae cultured in vitro for six days. Mellitic acid effected in concentrations between 0.5 and 15 mmol/l as compared with control cultures a concentration dependent inhibition of calcification and in concentrations above 2 mmol/l significant increases of the glycosaminoglycan content and growth of the explants, whereas DNA-, total protein- and hydroxyprolin content were not significantly influenced by concentrations up to 10 mmol/l.

Animals↗

PubMed1988

Structure and nucleotide sequence of the rat intestinal vitamin D-dependent calcium binding protein gene.

The vitamin D-dependent intestinal calcium binding protein (ICaBP, 9 kDa) is under transcriptional regulation by 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], the hormonal active form of the vitamin. To study the mechanism of gene regulation by 1,25-(OH)2D3, we isolated the rat ICaBP gene by using a cDNA probe. Its nucleotide sequence revealed 3 exons separated by 2 introns within approximately 3 kilobases. The first exon represents only noncoding sequences, while the second and third encode the two calcium binding domains of the protein. The gene contains a 15-base-pair imperfect palindrome in the first intron that shows high homology to the estrogen-responsive element. This sequence may represent the vitamin D-responsive element involved in the regulation of the ICaBP gene. The second intron shows an 84-base-pair-long simple nucleotide repeat that implicates Z-DNA formation. Genomic Southern analysis shows that the rat gene is represented as a single copy.

Amino Acid Sequence↗

PubMed1987

Molecular cloning of the cDNA and chromosomal gene for vitamin D-dependent calcium-binding protein of rat intestine.

A cDNA encoding the vitamin D-dependent rat intestinal calcium-binding protein has been isolated by screening a rat intestinal cDNA library. The cDNA is 406 nucleotides long and appears to contain all the sequences of the mRNA. The cDNA includes the entire protein coding region. It consists of 237 nucleotides coding for 79 amino acids, including the starting methionine, flanked by 62 and 107 noncoding nucleotides at the 5' and 3' ends, respectively. Using the cloned cDNA, we have isolated a genomic clone from a rat liver genomic library. Restriction mapping and Southern analysis using synthetic oligonucleotides localized the gene to a 4.0-kilobase-pair HindIII fragment.

Amino Acid Sequence↗

PubMed1986

Effects of mellitic acid (MA) and sodium fluoride (NaF) on the histological appearance of murine fetal tibiae cultured in vitro.

The aim of this study was to develop a standardized image analysis method for localization and quantitative measurement of calcified structures of murine fetal tibiae cultured in vitro as a completion and verification of previous biochemical studies. The calcified structures of bone stained by von Kossa silver technique and the epiphyseal cartilages showing intensive metachromasia with toluidine-blue staining were converted with grey-value window programs and afterwards the areas of the selected structures were measured. The histomorphological investigations showed that the murine tibiae, incubated for a period of 6 days in a medium with addition of 5 mmol mellitic acid, showed both a significant reduction of calcium deposits and an increase of epiphyseal intercellular cartilage matrix. The tibiae incubated in a medium with addition of 0.5 mmol sodium fluoride significantly showed an increase of calcium deposits in the thickened lamellae of the compacta. These histomorphological results confirm previous biochemical studies.

Animals↗