Chromosomal polymorphism of constitutive heterochromatin regions of chromosome 1, 9, 16, and Y is a stable evolutionary feature that is thought to cause no phenotypic alterations. The presence of definite ethinic and age-related peculiarities of chromosomal polymorphism variants was established. Some authors reported the relationship of the separate variants with the phenotypic characteristics, such as reproductive function, physiological and anthropometric indices, and oncological diseases. Nevertheless, the role of constitutive heterochromatin is still unknown. We experienced and reported short children associated with polymorphisms in chromosme 1qh+ and 16qh+.
Child ; Chromosomes, Human, Pair 1 ; Heterochromatin ; Humans

PURPOSE: This experimental study investigates the effect of mitomycin C(MMC) on the healing of sinus mucosal opening. METHODS: One hundred and twenty rabbits were used and divided into 8 groups of fifteen rabbits. A small(1.35 mm) or large(2.7 mm) diameter mucosal opening was created by drilling in the medial wall of the left maxillary sinus of rabbits and treated with MMC at a concentration of 0.2 or 2.0 mg/ml for 5 or 30 minutes. Five rabbits from each group were sacrificed at 1,2 & 4 weeks. The size of a remained mucosal opening was measured and light and electron microscopic examination were performed. RESULTS: After comparing the sizes of remained mucosal openings among the small opening groups(group 1,3 & 5), group 5 maintained larger opening at 2 weeks than the control group(P<0.05). Light microscopy of the specimens showed inflammatory and degenerative changes. The bone of the maxillary sinus exhibited minimal change induced by MMC. Scanning electron micrographs showed heterochromatin in nuclei and mitochondrial swelling of the epithelium. CONCLUSIONS: The MMC was effective in maintaining a larger mucosal opening than control group at least for 2 weeks following surgery.
Epithelium ; Heterochromatin ; Maxillary Sinus ; Microscopy ; Mitochondrial Swelling ; Mitomycin* ; Rabbits*

Roberts syndrome is an autosomal recessive disorder accompanied by limb defects, craniofacial abnormalities, pre-and postnatal growth retardation. Patients with Roberts syndrome have characteristic premature separation of heterochromatin of many chromosomes and abnormalties in celldivision cycle. We have experienced a case of Roberts syndrome in an immature neonate The patients showed characteristic clinical features of multiple, severe facial mid-line clefts, and tetraphoco-amelia. The brief review of the literlature was made.
Craniofacial Abnormalities ; Ectromelia ; Extremities ; Heterochromatin ; Humans ; Infant, Newborn

Aging ; Cellular Senescence ; Heterochromatin ; Humans ; Sirtuins ; genetics ; Stem Cells

Mitomycin C(MMC) is one of the alkylating agents, which is commonly used adjunctively to inhibit the over-growth of the fibroblasts in high-risk filtering surgery. However, it increases the incidence of the complications including persistent postoperative hypotony. The hypotony may be caused by the toxic effect of MMC on the ciliary epithelium. The morphological changes of the ciliary epithelium were evaluated using transmission electron microscope four and twelve weeks after the application of balanced salt solution(BSS) and MMC on the exposed sclera against the ciliary body in the rabbit eyes. There was no specific change in the ciliary epithelium four and twelve weeks after the application of BSS. Four weeks after the application of 0.2mg/ml of MMC, the mitochondria in the nonpigmented epithelium of the applied region were swollen mildly. The mitochondria of both pigmented and nonpigmented epithelia were swollen moderately in the region applied with 0.5mg/ml of MMC. Twelve weeks after the application of either 0.2 or 0.5mg/ml of MMC, the mitochondria were swollen markedly, the nuclear membranes in the pigmented and nonpigmented epithelia were wrinkled, and the heterochromatins of the nuclei faded in both applied and contralateral ciliary epithelia. These findings indicate that mitomycin C causes degenerative changes in the ciliary epithelium decrease aqueous production.
Alkylating Agents ; Ciliary Body ; Epithelium* ; Fibroblasts ; Filtering Surgery ; Heterochromatin ; Incidence ; Mitochondria ; Mitomycin* ; Nuclear Envelope ; Sclera

Activator protein-1 (AP-1) is an inducible transcription factor that contributes to the generation of chronic inflammation in response to oxidative and electrophilic stress. Previous studies have demonstrated that the PI3K/Akt1 pathway plays an important role in the transcriptional regulation of AP-1 expression. Although the histone post-translational modifications (PTMs) are assumed to affect the AP-1 transcriptional regulation by the PI3K/Akt pathway, the detailed mechanisms are completely unknown. In the present study, we show that heterochromatin 1 gamma (HP1gamma) plays a negative role in TPA-induced c-Jun and c-Fos expression. We show that TPA-induced Akt1 directly phosphorylates HP1gamma, abrogates its suppressive function and increases the interaction between histone H3 and 14-3-3epsilon. Collectively, these our data illustrate that the activation of PI3K/Akt pathway may play a permissive role in the recruitment of histone readers or other coactivators on the chromatin, thereby affecting the degree of AP-1 transcription.
Chromatin ; Heterochromatin ; Histones ; Inflammation ; Phosphorylation* ; Protein Processing, Post-Translational ; Transcription Factor AP-1* ; Transcription Factors

The aim of this investigation was to elucidate the changes in the cytoplasmic distribution of beta-actin, fibronectin, and laminin through mainly the morphological changes occurring in HeLa and L929 cancer cell treated with paclitaxel. Whether or not paclitaxel regulates cell proliferation was assessed with MTT assay. Possible influence on the distribution of beta-actin, fibronectin, and laminin in these cells was confirmed with immunocytochemistry and analySIS Auto software program. The changes in cell morphology were observed under inverted and electron microscope. The MTT assay showed that 1 micrometer and 10 micrometer concentrations of paclitaxel inhibited HeLa cell growth approximately by 20% to 80% and L929 cell by 27% to 44% in a dose- and time-dependent manner. The distribution of these proteins was changed from the condensed around nucleus and strong reaction to the weak throughout cytoplasm. The morphological changes indicated that paclitaxel changes the location or number of protein synthesis apparatus: damages of RERs, Golgi complex, and increase of heterochromatin. These data suggest that the growth inhibition and morphological changes of tumor cells induced by paclitaxel might be modulated by the rearrangement and decreased production of beta-actin, fibronectin, and laminin in cytoplasm.
Actins* ; Cell Proliferation ; Cytoplasm ; Fibronectins* ; Golgi Apparatus ; HeLa Cells ; Heterochromatin ; Humans ; Immunohistochemistry ; Laminin* ; Paclitaxel*

Chromatin texture, which partly reflects nuclear organization, is evolving as an important parameter indicating cell activation or transformation. In this study, chromatin pattern was evaluated by image analysis of the electron micrographs of follicular and papillary carcinoma cells of the thyroid gland and tested for discrimination of the two neoplasms. Digital grey images were converted from the electron micrographs; nuclear images, excluding nucleolus and intranuclear cytoplasmic inclusions, were obtained by segmentation; grey levels were standardized; and grey level histograms were generated. The histograms in follicular carcinoma showed Gaussian or near-Gaussian distribution and had a single peak, whereas those in papillary carcinoma had two peaks(bimodal), one at the black zone and the other at the white zone. In papillary carcinoma. the peak in the black zone represented an increased amount of heterochromatin particles and that at the white zone represented decreased electron density of euchromatin or nuclear matrix. These results indicate that the nuclei of follicular and papillary carcinoma cells differ intheir chromatin pattern and the difference may be due to decondensed chromatin and/or matrix substances.
Carcinoma, Papillary ; Chromatin* ; Discrimination (Psychology)* ; Euchromatin ; Heterochromatin ; Inclusion Bodies ; Normal Distribution ; Nuclear Matrix ; Thyroid Gland*

Prenatal chromosome analysis of amniotic cells at 18 weeks of gestation showed a male fetus to carry a large 15p+ derivative chromosome inherited from his mother. Extra genetic material on the short arm of chromosome IS was silver-negative with Ag-NOR (nucleolus organizer regions) stain, but stained darkly with C-banding method like the distal heterochromatic segment of the Y long arm. Fluorescence in situ hybridization (FISH) using two DNA probes (DYZ1 and D15Zl) showed a red fluorescent signal on 15p+ In addition to a green chromosome 15 centromere signal, confirming 15p to be from the distal Yq heterochromatin.
Arm ; Centromere ; Chromosomes, Human, Pair 15 ; DNA Probes ; Fetus ; Fluorescence ; Heterochromatin ; Humans ; In Situ Hybridization ; Male ; Mothers ; Pregnancy

Genomic instability, which occurs through both genetic mechanisms (underlying inheritable phenotypic variations caused by DNA sequence-dependent alterations, such as mutation, deletion, insertion, inversion, translocation, and chromosomal aneuploidy) and epigenomic aberrations (underlying inheritable phenotypic variations caused by DNA sequence-independent alterations caused by a change of chromatin structure, such as DNA methylation and histone modifications), is known to promote tumorigenesis and tumor progression. Mechanisms involve both genomic instability and epigenomic aberrations that lose or gain the function of genes that impinge on tumor suppression/prevention or oncogenesis. Growing evidence points to an epigenome-wide disruption that involves large-scale DNA hypomethylation but specific hypermethylation of tumor suppressor genes, large blocks of aberrant histone modifications, and abnormal miRNA expression profile. Emerging molecular details regarding the modulation of these epigenetic events in cancer are used to illustrate the alterations of epigenetic molecules, and their consequent malfunctions could contribute to cancer biology. More recently, intriguing evidence supporting that genetic and epigenetic mechanisms are not separate events in cancer has been emerging; they intertwine and take advantage of each other during tumorigenesis. In addition, we discuss the collusion between epigenetics and genetics mediated by heterochromatin protein 1, a major component of heterochromatin, in order to maintain genome integrity.
Biology ; Carcinogenesis ; Chromatin ; DNA ; DNA Methylation ; Epigenomics* ; Genes, Tumor Suppressor ; Genetics* ; Genome ; Genomic Instability ; Heterochromatin ; Histones ; MicroRNAs ; Sequence Deletion