Syphilis as a chronic systemic infection

During the last STDs'epidemic in Russia (1994 - 2004) over 2.7 min people have been infected with syphilis. At present the structure of syphilis morbidity is characterized by 37% of latent forms, including 1.5% late latency. The increased level of late latency may result from: an ever-growing number of those with asymptomatic syphilis; disorderly and self-dependent usage of antibacterial preparations; spread of the virus chronic infections (herpes, hepatitis B, C) altering the macroorganism immune response; alcohol and drug abuse which decreases the efficacy of specific therapy. In general, chronization of the syphilitic infection may be caused by antigenically inert treponemal cell surface; paucity of outer membrane protein; residence of treponemas within an immunoprotective niche; uncompleted phagocytosis of treponemes with macrophages. Syphilis remains an "infectio magna" and demands thorough attention to all diagnostic and therapeutic procedures on every stage of the disease.     

Biogeochemical interactions between iron and sulphate in freshwater wetlands and their implications for interspecific competition between aquatic macrophytes

1. Wetlands are threatened by desiccation, eutrophication and changing water quality, generally leading to greatly altered biogeochemical processes. Sulphate pollution can lead to severe eutrophication and sulphide toxicity, but may also interact with the availability of iron and other metals. 2. In the present study, we examined the biogeochemical interactions between sulphate and iron availability, and their effects on aquatic macrophytes, in a field experiment with enclosures. The natural iron supply by groundwater was mimicked by adding iron to the sediment, and the effect of increased sulphate concentrations in the surface water was also studied. The enclosure experiment was performed in a mesotrophic, anaerobic ditch in a peat meadow reserve in the Netherlands. In all enclosures, three Stratiotes aloides plants were introduced to serve as indicator species. 3. Addition of sulphate led to the mobilisation of phosphate, whereas addition of iron or both iron and sulphate did not affect P mobilisation. Growth of S. aloides was decreased by both iron addition and sulphate addition (sulphide toxicity). Addition of iron under sulphidic conditions, however, led to mutual detoxification of both toxicants (iron and sulphide) and did not decrease S. aloides growth. The uptake of metals was highest in the treatment involving sulphate addition, probably as a result of increased mineralisation of the peat soil. 4. Growth of Elodea nuttallii, which grew naturally in the enclosures, was stimulated by iron or iron plus sulphate addition. It did not, however, grow in the enclosures with sulphate addition, as a result of sulphide toxicity or sulphide‐induced iron deficiency. Under iron‐rich conditions, E. nuttallii appeared to be a better competitor than S. aloides and depressed the growth of the latter species. 5. We propose that the growth of S. aloides is directly regulated by interactions between sulphide and iron and indirectly by the effects of both compounds on the competitive strength of E. nuttallii. In general, we conclude that biogeochemical interactions between sulphate and iron can have a strong influence on plant species composition in freshwater wetlands, because of direct effects or changes in the competitive strength of plant species related to differential sensitivity to either iron or sulphide.     

Oncolytic poxviruses

The latest data on selection and construction of poxviruses capable of specifically lysing tumor cells of different genesis, inducing antitumor immunity and apoptosis of malignant cells are discussed. The review concerns several directions: virus attenuation, insertion of immunomodulatory protein genes, and anti-tumor protein genes. Thymidine kinase and viral growth factor genes make the greatest contribution to the virus attenuation as their inactivation results in the virus inability to replicate in non-dividing cells, thereby contributing to increased selectivity with respect to tumor cells. Among the immunomodulatory proteins, interleukins 2, 12, and granulocyte-macrophage colony-stimulating factor proved to be most promising for oncolytic virotherapy. An attempt to use p53 protein gene expressed by vaccinia virus for addressed apoptosis of tumor cells was reported. The use of the double and triple viral recombinants carrying genes of multidirectional action seems to be most promising. Encouraging results were obtained using vaccinia virus in the oncotherapy with prodrugs and angiogenesis inhibitors. At present, two poxviral strains are undergoing Phase III clinical trials as anti-tumor preparations in the USA.     

Lymphoid regulation of the proliferative stage in regeneration of the intestines and esophagus of rats

After the removal of a half of small intestine in the rats, the lymphocytes acquired the ability to stimulate the mitotic activity of crypts of the small intestine, large intestine and oesephagus in syngenic recipients. The ratio of mitotic phases in the experimental animals suffered no changes, the number of cells in the crypts increased reliably thus suggesting the true stimulation of proliferation. The lymphocytes of pseudooperated rats had no such ability.     

Principle of the supramolecular stacking of the cellular deoxyribonucleoprotein complex

Using cytofluorimetry with acridine orange staining and a modified thermal denaturation technique of cellular DNP, it has been shown that chromatin melting profiles of normal human nuclei (from lymphocytes and granulocytes) have distinct regularities. It is believed that these regularities reflect specific supramolecular chromatin organization. Parallel comparative analysis performed using electrophoretic fractionation and isoelectric focussing of nuclear proteins has revealed that: 1) peculiarities of chromatin melting profiles are independent of the quantity and molecular weights of chromatin proteins; 2) the lack of principal differences in chromatin melting profiles and the data on isoelectric points of nuclear proteins of granulocytes and lymphocytes from the same patient indicate that specific supramolecular organization of DNP-complex depends on the chromatin protein charge.     

Melting profiles for lymphocyte chromatin of healthy subjects and Down's disease patients obtained by the technic of cellular DNA absorption in ultraviolet light

Integral values of optical density (E260) were obtained for lymphocyte nuclei from normal people and those suffering from Down's syndrome during the melting of cells in media of varying ionic strength (0.15 M NaCl - control; 0.015, 0.0015 and 0.00015 M NaCl - experimental). The differences in E260 were obtained only during the melting of cells in 0.15 M NaCl. In lymphocytes from normal people, the distinctly reproducible hyperchromic effect was detected from 78 degrees (up to 35--40%), reaching the plateau by 96 degrees C (P less than 0.01). In identical conditions, the hyperchronic effect on aneuploid cells was revealed only after 98 degrees C (P less than 0.01). The data presented confirm the authors' concept of the greater condensation of aneuploidic genome.     

Characteristics of liver regeneration and growth in 3-week-old mice of different strains]

Three-week mice of C57BL strain are characterized by low proliferative activity of hepatocytes during normal growth of the liver. Hepatocytes of mice of this strain also had low proliferative activity 44 hours after partial hepatectomy (16%). Mice of the same age, but of other strains (mongrel, CBA, CC57BR) had higher mitotic indices both during normal growth and during regeneration (42; 70 and 60%, respectively). This peculiarity in the mitotic activity of hepatocytes of mice of different strains was also present 7 days after the beginning of the experiment. The data obtained indicated the genetic determination of the level of proliferative activity of hepatocytes.     

Dynamics of the activity of the normal mouse spleen killers after partial splenectomy

The activity of natural killers from the mouse spleen was determined by 51Cr clearance from labeled target cells (YAC-1) at different times after resection of the two-thirds of the spleen. In the early periods after operation, there was a decrease in the natural cytotoxic activity of splenocytes followed by a relatively rapid rise for 8 days until the maximum exceeding the cytotoxicity of intact spleen cells was reached. However, the total lytic potential of the regenerating spleen did not return to normal during 28 days.     

Phosphorylated derivitaves of All-Z and 3-demethyl-tri-TRANS, di-cis- hexaprenols as substrates for O-antigen polysaccharide biosynthesis in Salmonella anatum]

Phosphates of all-Z- and 3-demethyl-tri-trans, di-cis-hexaprenols have been prepared and studied as substrates for enzymes of the Salmonella anatum O-specific polysaccharide biosynthesis. Methyl group in alpha-isoprenic unit proved to be essential for the enzyme-substrate interaction, whereas the presence of E-isoprenic units near the omega-end of the polyprenol is not significant.