Complex Analysis of Diffusion Transport and Microstructure of an Intervertebral Disk.

We studied the relationship between diffusion transport and morphological and microstructural organization of extracellular matrix of human intervertebral disk. Specimens of the lumbar intervertebral disks without abnormalities were studied ex vivo by diffusion-weighed magnetic resonance imaging, histological and immunohistochemical methods, and electron microscopy. Distribution of the diffusion coefficient in various compartments of the intervertebral disk was studied. Significant correlations between diffusion coefficient and cell density in the nucleus pulposus, posterior aspects of annulus fibrosus, and endplate at the level of the posterior annulus fibrosus were detected for each disk. In disks with nucleus pulposus diffusion coefficient below 15×10-4 mm2/sec, collagens X and XI were detected apart from aggrecan and collagens I and II. The results supplement the concept on the relationship between the microstructure and cell composition of various compartments of the intervertebral disk and parameters of nutrient transport.

[The possibilities for diagnostics of prescription of death coming based on the changes in the lumbar intervertebral disks (the comparison of the morphological, immunohistochemical and topographical findings)]. / Vozmozhnosti diagnostiki davnosti nastupleniia smerti po izmeneniiam v poiasnichnykh mezhpozvonkovykh diskakh (sopostavlenie morfologicheskikh, immunogistokhimicheskikh i tomograficheskikh rezul'tatov).

The objective of the present study was the comprehensive analysis of the postmortem changes in the lumbar intervertebral disks within different periods after death. A total of seven vertebromotor segments were distinguished in the lumbosacral region of the vertebral column based on the examination of 7 corpses. All these segments were divided into three groups in accordance with the prescription of death coming as follows: up to 12 hours (group 1), between 12 and 24 hours (group 2), and between 24 and 36 hours (group 3) after death. The models of the segments thus obtained were subjected to the study by means of diffusion weighted MRI. The removed intervertebral disks were used for morphological and immunohistochemical investigations. The comparison of the diffusion coefficients (DI) revealed the significant difference between the intervertebral disks assigned to groups 1 and 2 (p<0.01). The number of the cells in the pulpal core, the vertebral end plate, and the fibrous ring in all the above groups of the intervertebral disks was significantly reduced (p<0.01). The analysis of the correlation dependence between cell density and diffusion coefficients has demonstrated the well apparent relationship between these characteristics of the intervertebral disks comprising groups 1 and 2. It is concluded that diffusion weighted MRI in the combination with the calculation of diffusion coefficients for the intervertebral disks provides a tool for diagnostics of prescription of death coming as confirmed by the results of the morphometric studies and immunohistochemical analysis.

[Study of DC-SIGN gene polymorphism in patients infected with Mycobacterium Tuberculosis strains of different genotypes in the Irkutsk Region].

Polymorphism of the promoter of DC-SIGN gene in Caucasians was studied at positions -336A/G and -871/G in 134 patients with pulmonary tuberculosis and 112 healthy individuals, who lived in the Irkutsk Region, Eastern Siberia. In 90 patients from the patient cohort M. tuberculosis DNA was isolated and investigated using the MIRU-VNTR typing test by 12 loci. Comparison of DC-SIGN gene polymorphism in patients with tuberculosis and healthy controls revealed no significant differences in loci -336A/ G and -871A/G. Analysis of MIRU-VNTR patterns identified 50 unique profiles, among which there were genotypes of the families Beijing, T. LAM, Haarlem, "Ural" (Haarlem 4) and X. Among 90 MIRU-VNTR genotypes, 42 profiles belonged to the Beijing family. Moreover, the minimum spanning tree (MST) test revealed a number of Beijing-like strains. The genotypes of the subjects affected with Beijing and Beijing-like strains and those affected with the strains of other families (non-Beijing) were compared. A significance reduction was found in the incidence of the -336G genotype among the subjects affected with Beijing strains versus those infected with non-Beijing strains at a frequency of 0.09 and 0.24, respectively (chi2 = 7.64; p = 0.006; OR = 2.7; 95% CI 1.1-6.1).