PubMed · 13965108
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
G ASBOE-HANSEN. 1963. Connective tissue.. https://doi.org/10.1146/annurev.ph.25.030163.000353
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Arrested follicular maturation is a characteristic feature of polycystic ovary syndrome (PCOS). Follicles mature in ovarian stroma composed of extracellular matrix (ECM). However, little is known of the expression of ECM genes in polycystic ovaries. The present study compares the expression levels of genes coding for collagens, matrix metalloproteinases (MMP), their inhibitors (TIMP) and cathepsins in polycystic ovaries using fertile and post-menopausal ovaries as controls. In northern analyses, the gene expression profiles of type I and III collagen of PCOS samples resembled those observed in normal follicular phase ovaries, while mRNA levels of proalpha1(IV) collagen and TIMP-3 mRNA were significantly lower in polycystic than control ovaries. During the normal menstrual cycle, an increase was observed in MMP-9 gene expression during the luteal phase. In post-menopausal ovaries, mRNA levels for type I, III and IV collagens and osteonectin were reduced, while the MMP, TIMP (excluding TIMP-3) and cathepsins did not reflect this metabolic down-regulation. Immunohistochemical staining for MMP-9 and TIMP-4 suggested differences between polycystic and normally functioning ovaries. These data demonstrate that normal ovarian functions are associated with changes in production and degradation of ECM. The alterations observed in the production and/or distribution of type IV collagen, TIMP-3 and TIMP-4 suggest involvement of basement membranes in the pathogenesis of PCOS.
Monochromatic x-ray computed tomography (CT) at two different energies provides information about electron density of human tissue without ambiguity due to the beam hardening effect. This information makes the treatment planning for proton and heavy-ion radiotherapy more precise. We have started a feasibility study on dual energy x-ray CT by using synchrotron radiation. A translation-rotation scanning CT system was developed for quantitative measurement in order to clarify what precision in the measurement was achieved. Liquid samples of solutions of K2HPO4 and solid samples of tissue equivalent materials were used to simulate human tissue. The experiments were carried out using monochromatic x-rays with energies of 40, 70 and 80 keV produced by monochromatizing synchrotron radiation. The solid samples were also measured in a complementary method using high-energy carbon beams to evaluate the electron densities. The measured electron densities were compared with the theoretical values or the values measured in the complementary method. It was found that these values were in agreement in 0.9% on average. Effective atomic numbers were obtained as well from dual-energy x-ray CT. The tomographic image based on each of the electron densities and the effective atomic number presents a different feature of the material, and its contrast drastically differs from that in a conventional CT image.
Explore the source record for details and available documents.