[Automatic morphometric analysis as a method for determining the level of extracellular matrix components and for quantifying nuclear antigens]. / Avtomatizirovannyi morfometricheskii analiz kak metod opredeleniia soderzhaniia komponentov vnekletochnogo matriksa i kolichestvennoi otsenki iadernykh antigenov.

Automated image analysis methods are highly important for biotechnology research. The authors developed and tested a program for the morphometric analysis of photomicrographs of the sections processed using the standard immunohistochemical examination protocols. The color deconvolution method used in the algorithm was proven to be effective in mapping the distribution of DAB chromogen in the sample containing multiple dyes. The experiment demonstrated that the level of extracellular matrix proteins could be comparatively quantified in different groups of samples. The effective methods for the quantitative analysis of the Ki-67 labelling index were also tested using the same algorithms. The developed program was published under free GPL 3.0.

Exfoliative cytology as a tool for monitoring pre-malignant and malignant lesions based on combined stains and morphometry techniques.

BACKGROUND: Prevention and early diagnosis have the greatest potential for public health and are the most effective method in the long-term to control oral cancer. The aim was to apply PAP staining together with AgNOR staining and morphometric analysis in oral exfoliative cytology, to determine the sensitivity and specificity of these methods in the detection of malignant changes for the purposes of both initial population monitoring and follow-up. METHODS: AgNOR, Papanicolau, and morphometric tests were conducted in samples of patients with oral cancer, oral potentially malignant disorders and controls (opposite side of lesions). Specificity and sensitivity values for each stain method and the curve under ROC area were estimated. RESULTS: The diagnostic variables which allowed greatest accuracy in identifying malignancy relative to the healthy control were cluster (76.92%), satellite (75.64%), and total (90%). The diagnosis was seen to be associated with PAP and total AgNOR, total AgNOR and PAP, total AgNOR and satellites and clusters, and total AgNOR nuclear area/cytoplasmic area ratio. CONCLUSIONS: The total number of AgNOR is a reliable marker for detecting neoplastic cells; this method increases sensitivity and specificity by decreasing the likelihood of false negatives or positives, as the accuracy obtained was 90%. It is also a low-cost, non-invasive, simple methodology that can be recommended to help the early detection of oral cancer and monitoring of patients with a first diagnosis of cancer.

Three-dimensional organization of promyelocytic leukemia nuclear bodies.

Promyelocytic leukemia nuclear bodies (PML-NBs) are mobile subnuclear organelles formed by PML and Sp100 protein. They have been reported to have a role in transcription, DNA replication and repair, telomere lengthening, cell cycle control and tumor suppression. We have conducted high-resolution 4Pi fluorescence laser-scanning microscopy studies complemented with correlative electron microscopy and investigations of the accessibility of the PML-NB subcompartment. During interphase PML-NBs adopt a spherical organization characterized by the assembly of PML and Sp100 proteins into patches within a 50- to 100-nm-thick shell. This spherical shell of PML and Sp100 imposes little constraint to the exchange of components between the PML-NB interior and the nucleoplasm. Post-translational SUMO modifications, telomere repeats and heterochromatin protein 1 were found to localize in characteristic patterns with respect to PML and Sp100. From our findings, we derived a model that explains how the three-dimensional organization of PML-NBs serves to concentrate different biological activities while allowing for an efficient exchange of components.

To the nucleolar density and size in apoptotic human leukemic myeloblasts produced in vitro by Trichostatin A.

The present study was designed to provide more information on nucleoli in apoptotic cells,which were represented in the present study by cultured leukemic myeloblasts (Kasumi-1 cells). The apoptotic process in these cells was produced by trichostatin A (TSA) that is a histone deacetylase inhibitor with strong cytostatic effects. The selected TSA concentration added to cultures facilitated to study apoptotic and not-apoptotic cells in one and the same specimen. The nucleolar diameter and density were determined using computer assisted measurement and densitometry in specimens stained for RNA. In comparison with not-apoptotic cells, in apoptotic cells, nucleolar mean diameter did not change significantly and nucleolar RNA density was also not apparently different. On the other hand, the cytoplasmic RNA density in apoptotic cells was markedly reduced. Thus it seemed to be possible that the transcribed RNA remained "frozen"within the nucleolus but its transport to the cytoplasm decreased or stopped. However, the possibility of the RNA degradation in the cytoplasm of apoptotic cells based on the present study cannot be eliminated. At this occasion it should be added that AgNORs reflecting nucleolar biosynthetic and cell proliferation activity in apoptotic cells decreased in number or disappeared. The presented results also indicated that large nucleoli intensely stained for RNA need not be necessarily related to the high nucleolar biosynthetic or cell proliferation activity and may be also present in apoptotic cells responding to the cytostatic treatment.

Proliferative activity in oral carcinomas studied with Ag-NOR and electron microscopy.

This study was conducted on 61 patients (27 males and 34 females). The age ranged from 27 to 81 years (mean 54 years). All suffered from oral squamous cell carcinoma and were treated by surgery and deep X-ray therapy (DXT). The UICC and TNM classification and staging recommendations were used for evaluation of the patients. All sections were stained with Ag-NORs stain for examination of the proliferative activity of the squamous cell carcinomas. Biopsies were also taken from another 6 cases--3 cases with normal striated muscle and 3 cases from normal oral mucosa--and served as controls. Statistical studies of Ag-NOR scores were classified into 3 scores: the p values of score I (ANOVA test) were .0001, score II (ANOVA test) was .0001, and score III (ANOVA test) was 06. Both scores I and II were highly significant and score III was significant. Electron microscopy (EM) showed tumor cells with irregular shape and size and with remarkable division of nuclei and chromatin clumps emarginated toward nuclear membrane, and some cases showed chromatin condensed at one pole of the nucleus. Few mitochondria with dilated cristae (?) and abundant rough endoplasmic reticulum (RER) were observed. Few apoptotic changes were noted. This study showed a high proliferation in poorly differentiated squamous cell carcinomas. The amount of Ag-NOR in poorly differentiated squamous cell carcinomas was a prognostic factor and represented an unfavorable prognostic feature in squamous cell carcinoma of the oral mucosa.

Structural model of full-length human Ku70-Ku80 heterodimer and its recognition of DNA and DNA-PKcs.

Recognition of DNA double-strand breaks during non-homologous end joining is carried out by the Ku70-Ku80 protein, a 150 kDa heterodimer that recruits the DNA repair kinase DNA-dependent protein kinase catalytic subunit (DNA-PKcs) to the lesion. The atomic structure of a truncated Ku70-Ku80 was determined; however, the subunit-specific carboxy-terminal domain of Ku80--essential for binding to DNA-PKcs--was determined only in isolation, and the C-terminal domain of Ku70 was not resolved in its DNA-bound conformation. Both regions are conserved and mediate protein-protein interactions specific to mammals. Here, we reconstruct the three-dimensional structure of the human full-length Ku70-Ku80 dimer at 25 A resolution, alone and in complex with DNA, by using single-particle electron microscopy. We map the C-terminal regions of both subunits, and their conformational changes after DNA and DNA-PKcs binding to define a molecular model of the functions of these domains during DNA repair in the context of full-length Ku70-Ku80 protein.