Granulometric composition of embryozems in the technogenic landscapes of the forest-steppe zone of Kuzbass

The fractional composition and size distribution of the soil of man-made landscapes is considered. The dependence of the formation of a certain type of embryozems in the forest-steppe zone of Kuzbass on the granulometric composition of soil-forming rocks was revealed. The content of physical clay throughout the profile of embryozems was calculated.     

Morphology and Antigenic Properties of Recombinant Analogs of the Marburg Virus Nucleoprotein

The full-length gene for Marburg virus (MV) nucleoprotein (NP) was cloned in prokaryotic pQE32 under the control of the T5 promoter and in eukaryotic pTM1 under the control of the T7 RNA polymerase promoter. Recombinant NP was synthesized in Escherichia coliand in human kidney cell line 293 cotransfected with recombinant vaccinia virus vTF7-3 expressing T7 RNA polymerase. On evidence of electron microscopy with immune detection, recombinant NP formed tubules of two types in E. coliand of a single type in cell line 293. ELISA and immunoblotting with polyclonal and monoclonal antibodies revealed common antigenic determinants in recombinant NP and natural MV NP.     

Effects of double ligation of Stensen's duct on the rabbit parotid gland

Salivary gland duct ligation is an alternative to gland excision for treating sialorrhea or reducing salivary gland size prior to tumor excision. Duct ligation also is used as an approach to study salivary gland aging, regeneration, radiotherapy, sialolithiasis and sialadenitis. Reports conflict about the contribution of each salivary cell population to gland size reduction after ductal ligation. Certain cell populations, especially acini, reportedly undergo atrophy, apoptosis and proliferation during reduction of gland size. Acini also have been reported to de-differentiate into ducts. These contradictory results have been attributed to different animal or salivary gland models, or to methods of ligation. We report here a bilateral double ligature technique for rabbit parotid glands with histologic observations at 1, 7, 14, 30, 60 days after ligation. A large battery of special stains and immunohistochemical procedures was employed to define the cell populations. Four stages with overlapping features were observed that led to progressive shutdown of gland activities: 1) marked atrophy of the acinar cells occurred by 14 days, 2) response to and removal of the secretory material trapped in the acinar and ductal lumens mainly between 30 and 60 days, 3) reduction in the number of parenchymal (mostly acinar) cells by apoptosis that occurred mainly between 14–30 days, and 4) maintenance of steady-state at 60 days with a low rate of fluid, protein, and glycoprotein secretion, which greatly decreased the number of leukocytes engaged in the removal of the luminal contents. The main post- ligation characteristics were dilation of ductal and acinar lumens, massive transient infiltration of mostly heterophils (rabbit polymorphonuclear leukocytes), acinar atrophy, and apoptosis of both acinar and ductal cells. Proliferation was uncommon except in the larger ducts. By 30 days, the distribution of myoepithelial cells had spread from exclusively investing the intercalated ducts pre-ligation to surrounding a majority of the residual duct-like structures, many of which clearly were atrophic acini. Thus, both atrophy and apoptosis made major contributions to the post-ligation reduction in gland size. Structures also occurred with both ductal and acinar markers that suggested acini differentiating into ducts. Overall, the reaction to duct ligation proceeded at a considerably slower pace in the rabbit parotid glands than has been reported for the salivary glands of the rat.     

Synthesis and antiviral activity of new 5-substituted 2'-deoxyuridine derivatives

New 5-azole- and 5-oxime-substituted analogues of 2'-deoxyuridine are synthesized. The analogues with azole ring manifest low toxicities and antiherpetic activities on Vero cell culture, the imidazole derivative being the most active. The inhibitory effects of oximes of 5-formyl-deoxyuridine are comparable with those of the azole-containing nucleoside analogues, although their cytotoxicities are found to be higher; oxime of 5-formyldeoxyuridine is particularly toxic. The nucleoside analogues synthesized exhibit no marked activity on cell cultures infected with various variants of poxvirus. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2005, vol. 31, no. 6; see also http://www.maik.ru.     

Sequence of a cDNA for mouse thymidylate synthase reveals striking similarity with the prokaryotic enzyme

We report the nucleotide sequence of a cloned cDNA, pMTS-3, that contains a 1-kb insert corresponding to mouse thymidylate synthase (E.C. 2.1.1.45). The open reading frame of 921 nucleotides from the first AUG to the termination codon specifies a protein with a molecular mass of 34,962 daltons. The predicted amino acid sequence is 90% identical with that of the human enzyme. The mouse sequence also has an extremely high degree of similarity (as much as 55% identity) with prokaryotic thymidylate synthase sequences, indicating that thymidylate synthase is among the most highly conserved proteins studied to date. The similarity is especially pronounced (as much as 80% identity) in the 44-amino-acid region encompassing the binding site for deoxyuridylic acid. The cDNA sequence also suggests that mouse thymidylate synthase mRNA lacks a 3' untranslated region, since the termination codon, UAA, is followed immediately by a poly(A) segment.