Structural-functional model of the mitotic chromosome.

In the present review the structural role of noncoding DNA, mechanisms of differential staining of mitotic chromosomes, and structural organization of different levels of DNA compactization are discussed. A structural-functional model of the mitotic chromosome is proposed based on the principle of discreteness of structural levels of DNA compactization.

Fusion, fragmentation, and fission of mitochondria.

Individual mitochondria which form the chondriom of eucaryotic cells are highly dynamic systems capable of fusion and fragmentation. These two processes do not exclude one another and can occur concurrently. However, fragmentation and fusion of mitochondria regularly alternate in the cell cycle of some unicellular and multicellular organisms.

[Traditional esophagectomy and esophago-gastrectomy vs. laparoscopic surgery. Evaluation and results].

The therapeutical choice in patients affected with esophagus disease depends on patients' conditions, as well as on the benign or malignant nature of the lesion. Actually, the surgical option is strongly conditioned by the state of health, particularly, the surgical therapy of resection, that is a mayor kind of surgery, has to value the heavy engagement to which the patient is submitted, meant as a clinical stress, caused by the clinical situation in which the patient can frequently feel: malnutrition, immunological and hematological conditions. It is in this field that the mininvasive surgery can be considered the most important surgical choice.

Organization of higher-level chromatin structures (chromomere, chromonema and chromatin block) examined using visible light-induced chromatin photo-stabilization.

The method of chromatin photo-stabilization by the action of visible light in the presence of ethidium bromide was used for investigation of higher-level chromatin structures in isolated nuclei. As a model we used rat hepatocyte nuclei isolated in buffers which stabilized or destabilized nuclear matrix. Several higher-level chromatin structures were visualized: 100nm globules-chromomeres, chains of chromomeres-chromonemata, aggregates of chromomeres-blocks of condensed chromatin.