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Biomedical subjects

K Kainulainen

Publications and source records attributed to K Kainulainen.

44 records · Page 3Linked to original sources

Progestin induction of 17 beta-hydroxysteroid dehydrogenase enzyme protein in the T-47D human breast-cancer cell line.

Steroid regulation of 17 beta-hydroxysteroid dehydrogenase (17-HSD) was studied in the T-47D human breast-cancer cell line, using a radioimmunoassay. In addition, 3 mRNA species (2.4, 1.4, and 0.9 kb) specific for the enzyme were shown to be present in these cells. All the synthetic progestins tested (ORG 2058, R5020, medroxyprogesterone acetate) significantly increased the immunoreactive enzyme protein concentration, while other types of steroids, such as testosterone, oestradiol and dexamethasone, were ineffective. The progestin-specific induction of 17-HSD was dose-related and was maximum in about 5 days. An antiprogestin, RU 486, when used in combination with synthetic progestins, blocked the progestin-induced increase of 17-HSD concentration very effectively. A good correlation was observed in the different experiments between the enzyme activity and the immunoreactive 17-HSD concentration. We conclude that progestins induce 17-HSD in T-47D cells and that the induction occurs via an increased accumulation of enzyme protein.

Breast Neoplasms↗

Deficient expression of the gene coding for decorin in a lethal form of Marfan syndrome.

The markedly decreased level of the messenger RNA of decorin, an abundant dermatan/chondroitin sulfate proteoglycan was found in the skin fibroblast culture of a lethally sick Marfan infant. Also, the amount of decorin polypeptide in the culture medium of the fibroblasts of this infant was markedly decreased. When the effect of interleukin-1 beta on the transcription of decorin was tested in these fibroblasts, the response was deficient as compared to control fibroblasts whereas transcription of type I and III collagen genes and versican was stimulated normally. The decreased decorin mRNA level, unresponsive to interleukin-1 beta in this lethally sick Marfan patient, stresses the significance of this proteoglycan in the formation of normal connective tissue. Furthermore, the low expression of this gene could be responsible for the connective tissue findings in this patient, representing a rare type of Marfan syndrome. The identical finding in three other, unrelated Marfan individuals suggests a more general significance of deficient decorin expression in this disease.

Blotting, Western↗

Location on chromosome 15 of the gene defect causing Marfan syndrome.

BACKGROUND: Marfan syndrome, "the founding member" of the heritable disorders of connective tissue, is a common autosomal dominant disorder with highly variable clinical manifestations in the skeletal, ocular, and cardiovascular systems. The fundamental defect leading to this disease has escaped definition despite decades of research efforts by several groups of investigators. METHODS AND RESULTS: Using linkage analyses with polymorphic markers of the human genome, we mapped the genetic defect to chromosome 15 in five families with Marfan syndrome. With three polymorphic markers we obtained definitive proof of linkage in these families (lod score = 3.92, theta = 0.0 +/- 0.11). The most probable location of the gene for the disease is currently D15S45 (lod score = 3.32, theta = 0.0 +/- 0.12). CONCLUSIONS: The chromosomal localization of the mutation in Marfan syndrome is a first step toward the isolation and characterization of the defective gene and serves as a diagnostic test in families in which cosegregation of these markers with the disease has been confirmed.

Chromosome Mapping↗

Marfan syndrome: exclusion of genetic linkage to five genes coding for connective tissue components in the long arm of chromosome 2.

Marfan syndrome represents a heterogeneous connective tissue disease, the symptoms arising in several tissues and organs. The defective gene(s) behind this autosomal dominant condition has not been found despite considerable research. The main targets of the research have been the genes coding for connective tissue components. Several of the candidate genes suspected to be defective in Marfan syndrome are located on the long arm of chromosome 2. These genes include a cluster of two genes coding for fibrillar collagens COL3A1 and COL5A2, and a third member of the collagen gene family: COL6A3. Furthermore, genes for elastin (ELN) and fibronectin (FN) are also located in this area of chromosome 2. We studied this chromosomal area using restriction fragment length polymorphism (RFLP) linkage analysis in five Finnish Marfan families with affected members in three generations. In two point linkage analyses, Lod scores of -3.192 (theta = 0.1) to COL3A1, -1.683 (theta = 0) to COL6A3 and -2.664 (theta = 0.01) to FN were obtained, whereas the linkage analysis between elastin and the disease was non-informative (Lod score 0.444, theta = 0). With the multipoint linkage analysis that permits simultaneous examination of several loci and more efficient use of family data, we obtained an exclusion of all these loci as the site of the mutation leading to Marfan syndrome in these families.

Chromosomes, Human, Pair 2↗

APOE alleles in Alzheimer's disease and vascular dementia in a population aged 85+.

Apolipoprotein E genotyping was carried out in a stratified random sample of 52 patients with Alzheimer's disease, 48 patients with vascular or mixed dementia, and 49 nondemented controls in a population-based study of people aged 85 and older (the Vantaa 85+ Study). Our results indicate that the apolipoprotein E epsilon 4 allele is associated with approximately a twofold increase in clinically diagnosed Alzheimer's disease in this very old general population aged 85+. When combined with previous studies, our data also suggest that the association is decreasing with age. In contrast, there appears to be no relation between apolipoprotein E alleles and clinically diagnosed vascular dementia.

Aged↗

Testing of human homologues of murine obesity genes as candidate regions in Finnish obese sib pairs.

The human homologues of recently discovered murine obesity genes provide relevant candidates to study the genetic component of obesity in humans. We analysed the human counterparts to murine obesity genes ob, db, agouti, tub, melanocortin 4-receptor (MC4-R) and mitochondrial uncoupling proteins 2 and 3 (UCP2 and UCP3), as well as two other chromosomal regions reported to be linked to obesity-related phenotypes in restricted populations. We found no significant evidence for linkage to any analysed loci in our total study material of 105 affected sib pairs collected from the genetically homogenous population of Finland. However, several markers on 14 cM chromosomal region flanking the MC4-R gene showed sharing of alleles identical-by-descent (IBD) more frequently than expected. A selected subset of non-diabetic obese sib pairs strengthened the P values down to 0.003 in this particular region. The smallest P value (P = 0.001) was obtained with a marker D18S487 in a subgroup containing only sib pairs with one lean and one obese parent. We therefore screened seven obese subjects included in our sib pair material for sequence changes in their MC4-R gene, but no mutations of apparent causal relationship were found. In conclusion, we could not find evidence for significant contribution of the chromosomal loci corresponding to the murine single gene obesity genes for human morbid obesity, but additional studies are still needed to clarify whether DNA alterations within or adjacent to the MC4-R gene play some role.

Adaptor Proteins, Signal Transducing↗